Sunday, August 29, 2010

Prion Disease Round Table Conducted Wednesday December 11, 2003 at Denver, Colorado R-CALF-USA Sponsored (REVISITED AUGUST 2010)

From: Terry S. Singeltary Sr.

Sent: Sunday, August 29, 2010 11:49 AM

Subject: Prion Disease Round Table Conducted Wednesday December 11, 2003 at Denver, Colorado R-CALF-USA Sponsored (REVISITED AUGUST 2010)


Below is the full text (unedited version) of the Prion Round Table Conducted Wednesday December 11, 2003 at Denver, Colorado R-CALF-USA Sponsored (REVISITED AUGUST 2010 by me). Periodically, I will comment on science that has changed since this Prion Round Table, and will reference the update scientific data. So the full text of the 2003 PRION ROUND TABLE IS HERE, but is broke up intermittently with my comments and updated scientific facts. It is interested for sure, to see the thought process in 2003 by the Government and the Industry, and compare to today. The ever emerging TSE science is changing, mutating and becoming more virulent, but sadly, the SSS policy is still going strong in the USA. OF course, Canada is finding cases, they are the only ones searching for cases in North America. Ramifications from all this, human TSE i.e. CJD and the new prionopathy there from is on the rise. ...TSS

Prion Disease Round Table Conducted Wednesday December 11, 2003 at Denver, Colorado R-CALF-USA Sponsored (REVISITED AUGUST 2010)

R-CALF-USA Sponsored Prion Disease Round Table Conducted Wednesday December 11, 2003 at Denver, Colorado

On Thursday, December 11, 2003, R-CALF-USA and a number of its affiliate cattle organizations sponsored a Prion Disease Roundtable in Denver, Colorado. Dr. R. M. Thornsberry, President of the Missouri Stockgrower’s Association was commissioned by R-CALF President Leo McDonnel to organize the roundtable and invite prion specialists to present information at the roundtable that would benefit the education of livestock producers throughout the United States.

Dr. Stanley Prusiner, the scientist who discovered prions, for which he won the Nobel Prize in medicine, was invited to the roundtable. Notes from Dr. Prusiner’s presentation on prions and prion diseases were presented to the roundtable by Dr. Thornsberry, who had attended one of Dr. Prusiner’s lectures on prion diseases. Although unable to attend the roundtable, Dr. Prusiner provided the roundtable with five papers published in prestigious peer reviewed medical and science journals. These papers were provided to all the attendees and key points from these papers were discussed at the beginning of the roundtable discussion. Dr. Prusiner emphasized normal cooking temperatures do not inactivate prions. This point is especially important when humans are exposed to Bovine Spongiform Encephalopathy (BSE) prions in the normal process of consuming beef muscle cuts that may contain significant nerve tissue. Dr. Prusiner’s laboratory is currently developing a live animal test to determine whether or not an animal is carrying BSE prions prior to entering the food chain for human consumption.

Dr. Jason Bartz, an applied science researcher from Creighton University, Omaha, Nebraska, was the second presenter at the roundtable. Dr. Bartz presented current research data on prion diseases and particularly outlined the pathogenesis of prion diseases. Dr. Bartz presented data that defined the ability of prions to replicate in secondary lymphoreticular system tissues, and the ability of prions to travel throughout the nervous system, finally locating within the brain or brain stem tissues where pathological changes occur. Dr. Bartz also presented data to illustrate the severity of prion disease appears to increase as the disease is passed from animal to animal. Dr. Bartz presented data to illustrate the infectivity and persistency of prions. Prions in brain tissue were heated to 600 degrees Celsius--that is over 1200 degrees Fahrenheit--and injected into brain tissue. These heat treated prions were still capable of causing prion disease changes. In other words, there is no commonly utilized method with which to inactivate prions on surgical instruments, surfaces, pens, corrals, chutes, ground, etc. Dr. Bartz also presented data that indicates tongue lesions or sores provide the mechanism for prions to enter brain tissue through the nerve that supplies the muscle tissue of an animal’s tongue. ...snip...end...(TSS/2010)

Completely Edited Version


Dr. Max Thornsberry: The question was asked: What brought this roundtable about? I was fortunate enough to listen to Dr. Prusiner's lecture by satellite at Washington State University on prion-related diseases. I was fascinated by the information he presented and the research he had administered. A number of livestock producers in the West this fall have found deer and elk on their property that have tested positive for chronic wasting disease. During a joint telephone conversation representing South Dakota Stockgrower’s Association, Montana Stockgrower’s Association, Missouri Stockgrower’s Association and others, the question was asked: Is chronic wasting disease infectious to cattle? Is it possible for cattle to get BSE (Mad Cow Disease) from deer and elk? From that series of questions came this meeting.

I'm going to go on the program first and go over Dr. Prusiner's lecture—the information I took down and thought was most pertinent. We want to have a basic understanding of what the human medical field thinks in terms of prion-relation diseases. Dr. Prusiner has won the Nobel Prize in Medicine for making the discovery that BSE is caused by an abnormal protein, which he calls prion Scrapie (PrPSc). For many, that's kind of a generic term for an aberrant prion. It may not mean it's the literal Scrapie prion, so he refers to all aberrant prions as Scrapie prions.

There are normal cellular prions, and Dr. Prusiner believes that sometimes, in some particular animals, the normal prion is converted into a prion Scrapie. That Scrapie prion is acquired at a certain level, and somehow stimulates the cell to start producing more of this abnormal prion. A conversion process takes place within the cell that converts normal cellular prions into abnormal Scrapie prions. The cell cannot clear these abnormal prions fast enough, resulting in the eventual death of the cell.

BSE is also called new variant Creutzfeldt-Jakob Disease (CJD) in human patients. Aberrant metabolism and the resultant accumulation of this BSE prion protein is what causes BSE or CJD in people.

The normal prion is soluble in a non-denaturing detergent, but prion pre-Scrapie is not soluble. This is a very tough piece of protein. Where the normal prion is readily digested by protease enzymes, the Scrapie prion is radically resistant to protease digestion.

Dr. Prusiner said BSE in humans is caused by consuming tainted beef. Apparently he is totally convinced of that. He also made a very poignant comment about a young woman, about nineteen, who has Creutzfeldt-Jakob Disease. They can find nothing in her history that would indicate she ever consumed beef. She was raised as a vegetarian. However, she was a consumer of gelatin in the form of Jello salads. He believes she picked that prion up through gelatin, and he's convinced that the normal processes that are used to denature protein and produce gelatin have no negative effect on the Scrapie prion and don't destroy the infective nature of this Scrapie prion.

He also says it's possible the normal prion is converted to the Scrapie prion. Something triggers the conversion process within the cell structure itself. It becomes, then, what he called, an inherited prion disease. There are some people who have, within their metabolism, the ability for this to occur. When it does occur, it somehow gets the cell oriented to producing more of the abnormal protein, and then it literally kills itself.

I'm sure you're familiar with a lot of these prion diseases, such as Kuru from cannibalism. Dr. Prusiner lists six ways for prion diseases to be transmitted from person to person:

Kuru—Ritualistic cannibalism of brain and nervous tissues.

Improperly sterilized brain electrodes (transfers the disease from person to person). He knows of no effective way to sterilize a brain probe.

Cornea transplants.

Use of human pituitary-gland proteins (growth hormone, HCG)

Dura mater graphs (surgery for spinal bifida)

Protein X—a factor defined by molecular genetic studies that binds the normal protein and facilitates prion pre-Scrapie formation


WE now know that blood can transmit nvCJD, and BSE can be transmitted to sheep by blood ;

Eurosurveillance, Volume 12, Issue 3, 18 January 2007 Articles Editorial team1


Citation style for this article: Editorial team. Fourth case of transfusion-associated vCJD infection in the United Kingdom. Euro Surveill. 2007;12(3):pii=3117. Available online:

Date of submission:

Fourth case of transfusion-associated vCJD infection in the United Kingdom

Asymptomatic vCJD abnormal prion protein in a haemophilia patient A person with haemophilia was recently found to have evidence of the agent (abnormal prion protein) that causes variant Creutzfeldt-Jakob Disease (vCJD) only in his spleen at post mortem.[1] This is the first time that vCJD abnormal prion protein has been found in a patient with haemophilia. To date, no haemophilia or bleeding disorder patients have been diagnosed with or died from clinical vCJD.

The investigations into the possible routes of infection for this patient are now complete and a risk assessment [2] has been carried out by the Department of Health. Assuming that the abnormal prion protein did indicate vCJD infection, the risk assessment considers four possible infection routes: dietary exposure to BSE; surgical procedures; transfusions with several units of red cells; and treatment with large amounts of UK-sourced Factor VIII. This included two batches of Factor VIII 8Y that were sourced from plasma pools which included plasma from a single donor who later developed clinical vCJD.

vCJD Risk Assessment Calculations for a Patient with Multiple Routes of Exposure Peter Bennett and Jenny Ball Health Protection Analytical Team Department of Health Wellington House 133-155 Waterloo Road London SE1 8UG 5th June 2009 Preface

News Archives

Volume 3 No 7; 20 February 2009

HPR Home Archives 2009 news

Post mortem finding of asymptomatic variant Creutzfeldt-Jakob Disease abnormal prion protein in a person with haemophilia

Multi-agency response to Wiltshire mine fire

Post mortem finding of asymptomatic variant Creutzfeldt-Jakob Disease abnormal prion protein in a person with haemophilia

A person with haemophilia has been found to have evidence of the abnormal prion protein that causes variant Creutzfeldt-Jakob Disease (vCJD) only in their spleen at post mortem. The post mortem was carried out as part of a study jointly co-ordinated by the UK Haemophilia Centre Doctors Organisation (UKHCDO) and the National CJD Surveillance Unit.

This haemophilia patient had been treated in the 1990s with several batches of UK sourced clotting factors, including one batch of Factor VIII that was manufactured using plasma from a donor who went on to develop vCJD. The plasma donor developed symptoms of vCJD six months after donating the plasma in 1996. The haemophilia patient, who was over 70 years old, died of a condition unrelated to vCJD, 11 years and one month after receiving the batch of implicated Factor VIII. The patient had no signs or symptoms of vCJD or other neurological disease when alive.

A final view as to how vCJD abnormal prion protein was transmitted to this haemophilia patient has yet to be reached because investigations are continuing to determine the most likely route of transmission. This is the first time that vCJD abnormal prion protein has been found in a patient with haemophilia, or any patient treated with plasma products.

All patients with bleeding disorders [1] who have been treated with UK-sourced pooled factor concentrates or antithrombin [2] between 1980 and 2001 [3] are classified as 'at risk of vCJD for public health purposes'. Special infection control precautions and other safety measures apply to these patients. This new finding does not change this advice.

This case does not change the public health vCJD 'at risk' status or management of any patients with bleeding disorders.

All haemophilia centre doctors were informed on Monday 16 February 2009 and asked to send a letter to their patients with bleeding disorders. Further information is available at

Letter to chief executives - July 2009 (PDF, 73 KB) Added/updated: 16 July 2009

Information for healthcare staff - June 2010 (PDF, 164 KB) Added/updated: 15 June 2010

vCJD Algorithm for pre-surgical roles - June 2010 (PDF, 28 KB) Assessment for patients undergoing surgery on high risk tissues or neuro-endoscopy. Roles and responsibilities for healthcare staff Added/updated: 24 June 2010

Highly transfused vCJD risk assessment form - July 2009 (Word Document, 328 KB) Added/updated: 16 July 2009

Letter to other blood laboratories - July 2009 (Word Document, 31 KB) Added/updated: 16 July 2009

vCJD Information for presurgical patients - July 2009 (PDF, 29 KB) Added/updated: 16 July 2009

Highly transfused vCJD risk assessment form and tool - February 2010 (Excel Spreadsheet, 2.7 MB) Added/updated: 12 February 2010


Great Britain has had one million cattle die of BSE and the average incubation time was five years. Dr. Prusiner has documented that brain extracts from cows with BSE will cause BSE-like disease if injected in the brain of cattle, sheep, mice, pigs and mink. It can occur in a little time as 200 to 300 days. The theory that this is a long-term incubation disease depends on the exposure. If the exposure is into the nervous system, then the incubation period appears to be much shorter.

There is no reliable specific test for prion diseases in a live animal that is known or available to the scientific community at this time.

Dr. Prusiner's theory is that BSE accumulated in Great Britain because of a major change in the manufacture of meat and bone meal. They went from a heat-type extraction to a chemical solvent extraction. When this change was made, they were able to solubalize and accumulate much more fat, and with that fat goes neural tissue. As they fed cattle to cattle and more cattle were slaughtered, it became an epidemic.

They are still seeing cases of BSE in those countries, but nothing like they were. Several new cases this past year have occurred in much younger animals that were not exposed to meat and bone meal and were born from animals not fed meat and bone meal. Where are these animals getting exposed to BSE prions? That is an unanswered question at this point.

Twenty-five percent of mice were able to develop CJD in 60 days when brain tissue from young people with new variant CJD was injected into the brains of susceptible mice. These prions are considered to be extremely infective. Dr. Prusiner believes new variant CJD is an infectious disease. If we get these prions into an environment where they can be consumed or come in contact with people, they are extremely infectious. His theory is that humans get new variant CJD from consuming BSE prions from cows.

He also made some comments about sheep and Scrapie. He said sheep with Scrapie may have a few BSE prions, but when the rendering process takes place, there is a transformation from the Scrapie prion or those prions die off or are inactivated. The only ones that survive are the BSE prions. Dr. Prusiner's theory is that when they were using sheep for meat and bone meal, the Scrapie prion was inactivated, but the BSE prion was much more resistant to inactivation, so in the processing of sheep for meat and bone meal, they actually concentrated the prion that he believes causes BSE.

He also developed a few therapeutic approaches to treating people with BSE. They have discovered these therapies through cell cultures. They've found that thorazine, chlorpromazine, and acepromazine have some effect in slowing down the progression of the disease. But the most interesting discovery was with a synthetic quinine product, Quinacrine. In cell culture, they have been able, literally, to slow the progression of prion diseases. They've had some clinical improvement in CJD patients. They have to use it at such high levels, a toxicity problem occurs.

In a minority of patients where the disease progression is slowed, some patients actually have a measured decrease in PRP Scrapie levels.

He classified prion diseases into three classes: Infectious (BSE, chronic wasting disease), sporadic, and genetic. He believes there are prion-related diseases such as ALS and Parkinson's disease.

Dr. Prusiner commented a number of times that prions are infectious. This is not an end-stage disease. He talked about the potential for spreading it through after-birth and the licking of newborn calves and possibly decomposing carcasses.

Prions contain protein. They are miss-formed proteins and they have no RNA or DNA. Somehow they are able to get a cell to reproduce themselves without the presence of genetic material. Prions also do not trigger the immune system, so there is no way to vaccinate against this disease, in his opinion. PRP Scrapie prions are natural at low levels in human patients, but the cells are able to clear that abnormal protein in a normal situation.

Dr. Prusiner said we don’t know the function of a normal PRP Scrapie prion in cells, but he believes there is a normal level of abnormal prions in cellular tissue of human patients. We don't know what that level is or when it reaches the point where it kills the cell. He believes there is some PRP Scrapie being formed all the time from normal prions, but the cell has a mechanism to clear the abnormal prion before it ever accumulates to a dangerous level.

The question was asked following the lecture: "How did BSE start in cows?" Dr. Prusiner believes in two theories. One is the sheep Scrapie theory mentioned previously. He does not believe the BSE prion is the sheep Scrapie prion. He believes they are two distinct prions, and the sheep Scrapie prion is much easier to inactivate than the BSE prion.

He also believes in a theory of spontaneous BSE or sporadic BSE. I thought Pasteur disproved spontaneous generation a long time ago, but evidently it's come back in vogue because Dr. Prusiner believes, and stands by the hypothesis that, for some reason, a cow just starts producing these abnormal BSE prions. He believes that cow died and ended up in the meat and bone meal and then the process started. That's the theory he outlines as his most significant hypothesis.

Dr. Spraker: If all people and animals always have a small amount of this abnormal prion, then why would you need a theory of spontaneous disease? Why not say something allows the abnormal to accumulate?

Dr. Thornsberry: Dr. Prusiner made that comment. He listed several human prion-related diseases and what the percentage was in the population. He feels that some of the prion-related diseases are genetic and some are spontaneous in a certain percentage of human patients. That was his hypothesis. I was surprised at the idea of spontaneous generation being brought up. That was the big theory before Pasteur came along—that maggots spontaneously came out of a piece of rotting meat. But that was exactly what he said: Spontaneous or sporadic BSE caused this disease to start to England

Dr. Bartz: I think of it as a stochastic process in humans. Sporadic CJD, to me, is real. You get sporadic production of an infectious agent. The way I look at it, the reason you don't see it in cattle or in sheep is a time factor. People come down with the clinical forms of sporadic CJD in their fifties and sixties. Cattle and sheep don't live that long. The theory is that as PrPC is being produced in the cell, it mis-folds into the Sc conformation randomly. If you're unlucky enough that this happens to you at an early stage of your life, it can progress and cause clinical signs.

Dr. Thornsberry: He believes that that occurs in everybody a little bit and then for some reason some individuals are not able to clear that abnormal prion?

Dr. Bartz: That I'm not sure about. I think sporadic CJD and familial CJD—something with mutations in the prion protein of the host—you increase the probability of this miss-folding.

Dr. Thornsberry: Here's another question—How does a prion get from the intestinal tract to the brain? Dr. Prusiner says it takes one billion or more prions orally to cause BSE to multiply in the lymphoid cells. From there, it goes to the brain. It may travel up the nerves, the spinal cord, or by the blood, the theory being that its primary means of getting to the brain is by traveling through spinal tissue.

The question was asked "How do you disinfect medical instruments?" His answer to that question was "Throw them away." He has found no effective way to disinfect them from prions.

There is no reliable blood test for prion-related diseases at this time. Conversion of PRP normal to PRP Scrapie occurs on the cell membrane with the relationship to cholesterol-rich domains on the cell membrane. This was the comment he made about natural conversion taking place.

"How do they multiply?" New prion pre-normal proteins are being formed and degraded into prion pre-Scrapie. As the Scrapie increases, more of it is somehow stimulated to be degraded into the Scrapie prion. In a situation where the Scrapie prion is there, as normal prion is being converted into abnormal prion, then the abnormal prion somehow triggers more abnormal prion to be converted until it builds up enough that it kills the cell.

Dr. Prusiner made some comments about Parkinson's disease. He said a protein being improperly handled in the substantia nigra cells is what causes Parkinson's disease because it causes a decrease in dopamine production. His theory is that Parkinson’s disease is a prion-related problem, that Parkinson's disease is the direct result of those cells being killed because of prion accumulation that he believes is a familial transfer.

"Can it be transmitted by blood transfusions?" His answer is that We don't know. We believe that ALS, or Lou Gehrig's disease, is a prion-related disease.

The last question that was asked of Dr. Prusiner was a simple question. The person said, "Dr. Prusiner, do you eat meat?" He answered immediately "Not in Europe." He was asked to elaborate, and he said these prion-related diseases are all over Europe. He said wherever you go, if you eat meat, you have the potential of picking them up. He believes the prions are in the muscle tissue. He does not believe they're just in the spinal column.

My son is an M.D. and they are getting a lot of information on these prion-related diseases and most of it is coming from Dr. Prusiner. The medical community has an understanding about prion-related diseases that's much different from that of the veterinary community, from what I can determine

At this point, I'd like each of you to introduce yourself and give a short summary of what you do.

Dr. Linda Detwiler: I formally worked for the USDA in the area of Transmissible Spongioform Encepthalopathy diseases. I work currently as an independent consultant to the food service industry, particularly, McDonalds Corporation, ….rest of comments inaudible…….

Dr. Susan Keller: After graduating from veterinary school, I had practiced for ~10 years as a predominately large animal veterinarian in North Dakota before becoming the Deputy State Veterinarian with the North Dakota Board of Animal Health and the North Dakota Department of Agriculture in 1997. Current responsibilities include serving as the Designated Scrapie Epidemiologist for ND and have been certified at Plumb Island as a Foreign Animal Disease Diagnostician.

Dr. Jason Bartz: I received a PhD from the University of Wisconsin in 1998 and I worked with Drs. Judd Akin and Dick Marsh. I studied mechanisms of inter-species transmission of prion diseases. I was a post-doctoral fellow with Richard Besson. I studied pathogenesis, asking questions about how the agent gets from the periphery to the central nervous system. In September, I started a faculty position at Creighton University and I'm setting up a lab to continue study of prion pathogenesis.

Dr. Terry Spraker: I graduated from vet school in 1972. I have a PhD in pathology and I'm board-certified in veterinary pathology. I saw CWD as a graduate student and didn't know what it was at that time. I've been working with it since then, looking at pathogenesis of the disease.

Dr. Thornsberry: I feel honored to have you all here and I hope we'll have an interesting dialogue. We want to make this information available to the cattle industry and to veterinarians, so anything you think is pertinent, please tell us.


Dr. Jason Bartz: Dr. Thornsberry asked me to talk about what is the risk of transmission of chronic wasting disease in cattle? Unfortunately, I cannot directly answer that. What I'm going to talk about is some of the basis science behind it and what we know about interspecies transmission. You can have five factors affecting interspecies transmission in the natural setting. The first is the question "is infectivity shed into the environment?" Can PrPSc survive in the environment? Can PrPSc reach a new host species? Is the agent transferred between deer and cattle? I'm going to spend most of the time on these last two points: "how does the agent get from the periphery to the central nervous system where it causes disease?" Finally, I'll talk about the species barrier effect. "Can PRPSC from one species convert to the PRPSC from the host into a new PRPSC molecule?"

What are prion diseases? All prion diseases are transmissible. They're neurodegenerative diseases and they have long incubation periods of months to decades. They're characterized by the spongiform degeneration. Clinically, they have motor and/or behavioral/cognitive deficits. There's no effective therapeutic treatment. They're all inevitably fatal. There's no adaptive immune response and there are no antibodies produced.

The animal prion diseases include Scrapie, found in sheep and goats. It's been known in the United Kingdom for over 200 years. It was first identified in the US in 1947. It has a worldwide occurrence with the exception of New Zealand and Australia

Transmissible mink encephalopathy is a prion disease of ranch-raised mink. It was first identified in the 1940s. There have been three major occurrences in the United States. The latest outbreak was in Wisconsin in 1985. It's a rare disease.

Bovine spongiform encephalopathy was first identified in the UK in 1986. Clinically it's characterized by an aggressive behavior and it's named mad cow disease. It was appreciated that it was a food-borne disease, so in 1988, a bovine feed ban was instituted. Amidst concerns about the transmission of BSE to humans, a specified risk materials ban was put in place in 1990. This banned tissues such as central nervous system tissues and spleen, which harbor high level of infectivity in cattle, from going into the human food chain. In 1996, a variant Creutzfeldt-Jakob disease was identified. It's distinct from the classical forms of CJD. First of all, the age of onset of variant CJD is much younger. The first few cases of variant CJD were people in their teens and twenties. Normally this disease is in people in their fifties and sixties.

The neuropathology is very distinct in variant CJD compared to other forms of CJD. Stains reveal distinctive amyloid plaques that are not observed in other forms of CJD. In the original study that identified variant CJD, an epidemiological study was performed and the only common risk factor that was identified was the emergence of BSE in the UK at that time. This suggested that BSE was able to infect people, resulting in variant CJD.

Two studies support this hypothesis. The first is experimental transmission of BSE to macaques. The neuropathology of BSE in infected macaques is indistinguishable from that of variant CJD. The second series of experiments uses a technique called lesion profile. Lesion profiling is a technique where you can distinguish distinct prion strains by passage in mice, by quantifying their neuropathological features. In this series of experiments, mice were infected with either BSE, variant CJD, or sporadic CJD. The mice became clinically ill. Their neuropathological features were quantified and represented as lesion profiles. Importantly, the lesion profile of mice infected with BSE is the same as that of mice infected with variant CJD and it's distinct from that of mice infected with sporadic CJD. This indicates that the same prion strain that causes BSE also causes variant CJD and is consistent with the hypothesis that BSE was able to infect humans, resulting in variant CJD.

I'd like to speak a little bit about chronic wasting disease. It was first identified in 1967 in Ft. Collins, Colorado. It has an expanding geographical range. It's been found in several states in captive herds and has also been found in wild deer and elk. The clinical signs include excessive salivation, reduced fear of humans, and distribution of infectivity in the host. It seems to differ in deer infected with chronic wasting disease, PRPSC seems more predominant in the secondary lymphoreticular tissues compared to elk.

There have been quite a few experimental transmission studies of CWD. It's been successfully transmitted by the IC route in goats, mink, ferrets, cattle, and squirrel monkeys.

Physical Properties and Etiological Agents

This agent is highly resistant to UV radiation. UV radiation historically is used to inactivate agents, and a mechanism it uses is to destroy the nucleic acid of the infectious agent. However, prion diseases are very resistant to UV inactivation. One of the practical aspects of this is that for persistence of an agent in an environment, sunlight is a very good means of handling it by destroying nucleic acid genomes.

The prion agent is very stable in acid and alkali. Little infectivity is lost between ranges of pH 2.5 and 10. However, you can lose infectivity in protein denaturance or chemotropic agents such a phenol or high concentrations of urea. RNAase and DNAase do not have any elicitable effect on infectivity.

Treatments that destroy protein and nucleic acids do not destroy infectivity. This has ramifications in what the etiological agent really is.

Another physical property is that it can survive in the environment. This is a paper by Brown in 1991 where he buried the prion in flower pots in his garden for three years. When he dug up the flower pots, there was still infectivity detected in the soil but not in the sub-soil. The two points we want from this paper are that (1) the agent can survive in the soil for three years and (2) based on this study, it does not seem to be leaching out.

In another paper from Brown in 2000, he took either fresh brain or formalin fixed brain and treated it at different temperatures ranging from 150 degrees Celsius to 1000 degrees Celsius. When he treated brain material at 600 degrees Celsius, the brain material actually caught on fire and all that was left was black ash. When he took this material and inoculated it back into recipient animals by the IC route, these animals came down with disease, indicating how resistant this agent is to different environmental and physical treatments.

What Do We Know About the Agent?

When you enrich the amyloid deposits or amyloid plaques that occur in the CNS of prion-infected animals and examine them by electronmicroscopy, you see these plaques are comprised of linear non-branching amyloid fibrils. When you do biochemical analysis of this amyloid fibrils, the main component of the amyloid fibrils is the prion protein. When you enrich the plaques from the brain and the fibrils from the plaques and the protein from the fibrils, you enrich for infectivity. Subsequent studies have shown that the prion protein is encoded by the host, and this is important because it eliminates the possibility that the prion protein is a viral by-product.

This suggests the prion agent is comprised solely of protein. The idea for a self-replicating protein is not new. It was first proposed in 1967 by a mathematician name Griffith. In 1982, following the identification of the prion protein, Stan Prusiner developed the prion hypothesis that states that the etiological agent for these diseases is comprised solely of the prion protein.

The prion protein exists in two forms. It's encoded by the host. The PRPC is for cellular and the PRPSC is for Scrapie. PRPC has a high ________ content. It's sensitive to proteinase digestion. It's soluble in detergents. It's not associated with infectivity. The function of PRPC right now is not known.

PRPSC is post-translationally-derived from PRPC. It has a high beta sheet content and this is consistent with PRPSC being an amyloid protein. It has a core that is highly resistant to protease digestion. PRPSC is a soluble in detergent and it is thought to be the sole component of the infectious agent, although I should point out this has not been formally proven.

How does a protein replicate? I think replication is a poor word for what prions do. "Conversion" is a much better descriptive word. One mechanism that's been proposed is nucleation dependent polymerization where in the infectious form of the disease, where the PRPSC of aggregate is being inoculated into the host, it encounters a PRPC molecule from the host, and it is incorporated into the growing amyloid fibril. Based on this model, PRPC should be very limiting in this conversion step. This has been borne out by transmission studies wherein normal mice, if you IC inoculate, that incubation period is about 130 days. If you take out PRPC, this is in transgenic mice that do not express PRPC, these are resistant to infection. Then if you make transgenic animals that over-express PRPC, these animals have a much shorter incubation period.

This is a paper showing that RNA is enhancing PRPC to PRPSC. What we know where the conversion occurs in the cell, there's not a good likelihood of RNA being located there. I don't know if RNA has specific properties that aid in conversion that another molecule in the cell may have.

Strain Diversity in Prions

Historically, prion strains have been characterized by differences in incubation period, and most importantly, differences in neuropathological features in the central nervous system. Sometimes they even have different clinical signs. One of the main arguments against the prion hypothesis has been "how do you have strain diversity in the absence of the nucleic acid genome, since, according to biological dogma, the differences in the genome of an infectious agent result in strain differences? It's recently becoming increasingly clear, that the conformation of PRPSC can encode for strain diversity. Different strains have different properties such as susceptibility to protease digestion, migration, polypeptide migration on western blot analysis. FTIR analysis has been used to demonstrate that the hyper and drowsy strains of TME have different ratios of alpha and beta sheet structure.

Investigators have also used a technique called glycoform ratio where they quantify the three different glycoforms of PRPSC and come up with a distinct ratio that correlates with strain properties as well. Based on these and many other studies, it seems that the conformation of PRPSC is actually the molecule that encodes for strain diversity in prion diseases. So here's a mechanism to try to explain how an agent in the absence of nucleic acid genome can have strain diversity.

To summarize the agent, there's no nucleic acid genome. It seems to be comprised solely of PRPSC. It's very resistant to physical degradation. The strains of prions are encoded by the conformation of PRPSC.


How does the agent get from the periphery to the central nervous system where is causes disease? I'll talk about oral exposure, since there's experimental and epidemiological evidence that this likely occurs in kuru through the practice of ritualistic cannibalism, and also in TME and BSE through contaminated foodstuffs. People have speculated it happens in variant CJD through the consumption of BSE-contaminated food, and also in chronic wasting disease and Scrapie in sheep and goats.

Infectivity, or PRPSC, is first detected in secondary lymphoreticular tissues, such as spleen and lymph nodes. Within spleen and lymph nodes, PRPSC accumulates in follicular dendritic cells. One the agent replicates in secondary LRS tissues, it's next detected in the central nervous system. There is rapidly replicates in the CNS. It's thought this replication kills neurons, leading to the onset of clinical signs and eventual death of the host.

In lymphoreticular system tissues, PRPSC is mainly detected in follicular dendritic cells, but also to a limited extent in tingible body macrophages. This and other studies have fairly clearly demonstrated that FDCs can replicate prions, and right now it's unclear if the tingible body macrophages are replicating agents or simply just phagocytosing PrPSc

Two pathways of neuro-invasion have been identified. One utilizes sympathetic internervation. This was an experiment performed by Kimberlin in 1989. This was following intra-gastric infection of rodents with prions. At selected time points, tissues were collected and inoculated back into recipient mice to assay for infectivity. The first place that infectivity was detected was in secondary LRS, tissues, such as Peyer's patches and lymph nodes. The first place in the central nervous system that infectivity was detected was in the thoracic spinal cord, and once it reached the thoracic spinal cord, it could travel caudally and cranially, eventually reaching the brain and killing the host. From this and numerous other studies, it seems that infectivity can spread via the enteric and sympathetic nervous system to the thoracic spinal cord and then eventually reach the brain.

A second route of neuro-invasion has been identified that utilizes para-sympathetic internervation. From experiments in hamsters, it seems that following oral infection, the agent can be transported directly to the brain stem via the vagal nerve to the DMNV.

To summarize these two routes of infection, once the agent gets of the GI tract, it can go up sympathetic internervation to the thoracic spinal cord and travel to the brain, or it can get into parasympathetic internervation and be directly transmitted to the brain stem.

This part of the pathway has been fairly well worked out. So what's happening in the gut to get it into the nerve? This is not so well worked out. One study looks at transporting it across the gut lumen into the host. It seems that M cells are able to transport PRPSC across the lumen. Once it gets across the lumen, it's thought it associated with follicular dendritic cells, replicates, and then can neuro-invade.

So how does the agent get from the follicular dendritic cell into the nerve? That's another black box. Recently there's been a paper where they use transgenic animals, and in these transgenic animals, the distance between the follicular dendritic cells and the sympathetic internervation has been reduced. When you reduce the distance between the nerves and the FDCs, you reduce the incubation period. This suggests there's a direct transfer between infectivity from FDCs and to the nerves.

Some of the work I've been involved in is figuring out alternative routes following oral exposure. Once the agent gets into the gut, it neuro-invades via sympathetic or parasympathetic internervation. I was interested in alternative routes along the alimentary tract. A tissue that is highly internervated and also has associated LRS tissue is the tongue. But as you know, the tongue has an epithelial layer that prevents infectious agents from crossing it. The epithelial lay can become damaged. Infections of the oral cavity can damage the epithelial layer. Microbial agents such as thrush, which are common in infants but also can occur in many compromised adults can degrade the epithelial layer of the oral cavity.

More common than tongue infections is probably lesions in the oral cavity. In animals, especially ruminant species, cuts in the oral cavity are quite common. We wanted to test the hypothesis that if the agent can get in the tongue, it can cause disease. To do that, we inoculated hamsters in the lingual muscles of the tongue with a hamster-adaptive strain of TME called hyper-TME. We found that it can cause disease and the incubation period is 79 days. To put this into context, if you inoculate animals directly into the brain, the incubation period is 59 days. If you inoculate in the peripheral nervous system, in the sciatic nerve, it's slightly longer—68 days. When you go extra-neurally, the incubation period is much longer. Intraperitoneal is 101 days; IV is 118; IM is 142. When you take the same dose of agent and dry it on a food pellet and feed it to an animal, this is a long incubation period and very inefficient. Only one out of six animals comes down with clinical signs.

A short incubation period does not necessarily mean an efficient establishment of infection. To test for efficiency, we did the dose-response curve. In this experiment, we took 10-fold serial-dilutions of agent and inoculated them into the lingual muscles of the tongue. What we found was that, as you dilute out the agent, you extend the incubation period. You get about 107 dilution and only one of the five animals comes down with this very long incubation period. From this we can calculate the titer. The titer by this route is 108.4 LD-50s per gram of inoculum. When we do the same sort of dose-response experiment, this time directly inoculating into the brain, the relative titer is 109.8 LD-50s per gram of inoculum and you can see that inter-tongue infection is only 10100-fold less efficient than a direct inoculation to the brain.

When we do this same experiment drying the inoculum on a food pellet and feeding it, it's a very inefficient route of infection, 103.4 LD-50s per gram, and this indicates that inter-tongue infection is 100,000-fold more efficient at causing disease than ingestion of the agent.

Next we wanted to ask the question, "Can lesions on the surface of the tongue increase the susceptibility of the host to prion infection?" Here we had four experimental groups. Our positive control was direct inoculation of the tongue, and as expected they came down with a short incubation period, 182 days. All the animals got the disease.

Our second control group was per os. Here, three of the 15 animals came down with the clinical signs at 185 days. For our third group, we placed inoculum on the surface of an unlesioned tongue. In these animals, five of the 15 developed clinical signs with an incubation period of 184 days, similar to the per os. In our experimental group, a small lesion was placed on the surface of the tongue. The same dose of inoculum was placed on that lesion, and in this group, all fifteen animals developed clinical signs with an incubation period of 161 days. Interestingly, these first five animals had an incubation period similar to direct inoculation of the tongue. This experiment demonstrates that a lesion on the surface of the tongue can increase the susceptibility of a host to prion infection.

To summarize the transmission data, inoculation into the tongue is 100,000-fold more effective than ingestion, at least in hamsters. Lesions on the surface of the tongue increase the susceptibility of the host to TME infection.

Routes of Efficiency

Why is this route so efficient? If we go back to our general schematic of prion replication, in peripheral routes, prions replicate in secondary LRS tissues prior to neuro-invasion. We set up a temporal study. Following tongue infection, we collected spleen and the sub-mandibular lymph node (the lymph node that drains the oral cavity, including the tongue). In the spleen, we were unable to detect PRPSC by western blot out to 10 weeks post-infection. This was just prior to the onset of clinical signs. As a positive control, we took a spleen from an animal that was intra-cerebrally inoculated and we could detect PRPSC in the spleen.

In the sub-mandibular lymph node, we were able to detect PRPSC at one week post-infection. It increased in abundance to three weeks post-infection and then plateaued out at five weeks post-infection. Based on this data, we would think the sympathetic route was involved in transport of the agent to the central nervous system. Based on this model, following inter-tongue infection, the agent drains to the sub-mandibular lymph node, replicates in this lymph node, travels via sympathetic internervation through the superior cervical ganglia, down the sympathetic chain. It should first be detected in the central nervous system in the thoracic spinal cord.

To test this, we set up a temporal study following inter-tongue infection and we collected the spinal cord and did western blot analysis. At seven weeks post-infection, we could not detect PRPSC in the cord. At eight weeks post-infection, we could detect PRPSC in the spinal cord. We detected it not only on the thoracic segments but also in the cervical segments. At nine and 10 weeks post-infection, PRPSC levels accumulate. This data was inconclusive in that not only was it in the thoracic, but in the cervical.

Next we asked the question, "Where in the brain or brain stem do you first see PRPSC following IT infection?" This time we used immunohisto-chemistry. We found that the first place PRPSC is identified is in the hypoglossal nucleus. By six weeks post-infection, PRPSC staining was wide-spread throughout the hypoglossal nucleus. The significance of this staining is that the hypoglossal nucleus contains only motor neurons, and the only function of the motor neurons in the hypoglossal nucleus is to internervate the tongue.

Dr. Detwiler: Do you say that the prion goes from the tongue to the sub-mandibular lymph node through nerves or through the lymphatic flow?

Dr. Bartz: We think it gets to the lymph node just via the lymphatic flow. There's no neural connection between the lymph node and the tongue.

Dr. Thornsberry: So when the lymphatic flow gets to the lymph node, then it dumps into the blood.

Dr. Bartz: Right. But why do we see PRPSC in the sub-mandibular lymph node at one week post-infection, but by the time clinical disease occurs, we can't detect it in the spleen? If it's in the blood, it should seed all the lymphatics in the host, but it doesn't

Dr. Spraker: Deer lymph nodes are 10 times better than spleen.

Dr. Detwiler: In sheep with sheep Scrapie, on this widespread distribution from multiple tissues at multiple sites, within the incubation period, how would you explain that from the spread of either the sympathetic or the para-sympathetic without some kind of circulatory process?

Dr. Bartz: It could get in the blood and it could be neuro-invading by 10 different routes. We don't know. But this is the main route, so the first place we see it is in the hypoglossal nucleus. It's the only place we see it in the brain until four weeks post-infection.

This mapping study is consistent with previous reports. When people use trans-neural viral tracers such as rabies and they inject the hypoglossal nerve, they find that it goes to the hypoglossal nucleus, and then the second order neurons that project afferents onto the hypoglossal nucleus in this reticular formation and all the different structures we identify PRPSC, so it seems to be transynaptically transported to second-order neurons, the same as other trans-neural viral tracers.

To summarize inter-tongue, as we think of inter-tongue infection, the agent is getting into the hypoglossal nerve and is being retrogradily transported at the hypoglossal nerve to the hypoglossal nucleus. It can replicate in the hypoglossal nucleus and then be transynaptically transported to second-order neurons, and eventually we think that PRPSC gets to the clinical target areas, resulting in clinical signs and death of the host.

Replication and Neuro-Invasion

The hypoglossal nucleus was not the first place we identified PRPSC in the host. It was in the sub-mandibular lymph node. We wanted to ask the question, is replication in the LRS system required for neuro-invasion following inter-tongue infections? To investigate this, we used mMT mice, which are transgenic mice that has a disruption in the immunoglobulin chain and they lack B lymphocytes. Since they lack B lymphocytes, which secrete factors that support FDC maintenance, they do not have follicular dendritic cells.

Previous studies using these in prion diseases have shown that they're susceptible to IC infection, and this means that once the agent gets to the brain, it can replicate and cause disease. But following a IP infection, they don't come down with disease. If you look in secondary LRS tissues, there's no detectable infectivity or PRPSC.

Using these mice following inter-tongue infection, if the animals come down, that would mean that replication in the secondary LRS tissues is not required for neuro-invasion and to set up this experiment, we had two different sets of mice. We had the mMT mice, which cannot replicate agent in the secondary LRS tissues, and we used C-57 black six mice, which can replicate prions in secondary LRS tissues. We inoculated them directly into the brain and had an incubation period of 160 days. We did an IP inoculation. Wild types come down at 216 days. The mMT’s are resistant. All of this is consistent with previously-published studies. We did an IT inoculation into wild type mice with 213 days incubation. All the mice came down. We did an IT inoculation with the mMT mice and got a similar incubation period—217 days with five of the six mice developing clinical signs. We did western blot analysis on secondary LRS tissue in all these mice, and consistent with what other people found, we were unable to detect PRPSC in the spleen or sub-mandibular lymph node. This data is consistent with the hypothesis that replication in secondary LRS tissues is not required for neuro-invasion following inter-tongue infection.

To summarize the pathogenesis, in general, following a peripheral infection, you get transport and replication in secondary LRS tissues. Once it replicates in these tissues, neuro-invasion occurs and you get a rapid accumulation of PRPSC in the brain. So far there have been three routes of neuro-invasion identified following oral infection, two of which originate in the gut using either sympathetic or parasympathetic internervation. The third are the studies with motor neurons—the oral cavity directly transporting agent to the brain.

Question: You said that's the normal progression of infection—that it normally goes into those tissues and then makes its way to the nervous system. But you've proven that's not required?

Dr. Bartz: I think the LRS is an amplifier of the agent in the periphery. You probably need a certain dose. You either need the agent to be in proximity to the nerve or replicate to a high enough dose it can get there. You can probably overcome this with a high enough dose, but if you give a low dose, you probably need replication in the host. So I think the LRS is a spot in the host where the agent can replicate in the periphery to facilitate neuro-invasion. The LRS tissues that prions replicate in—as far as I know, there's no deficit in these tissues.

Comment: With deer, the hypoglossal nucleus is one of the latter nuclei to be infected. In deer, 99% of the lymphoid tissue will be infected in early cases, even before the brain is infected. On the opposite side, there's a percentage of elk infected that do not have PRP in lymph nodes. So an alternate route of infection has been postulated.

Dr. Bartz: I'm not making any sort of assertion that this happens in natural cases. The only reason I think it's interesting to discuss is because it's so efficient.

Question: Why couldn’t you have multiple routes?

Dr. Bartz: You could. If it occurs in one out of every thousand cases, would we find it? Maybe, maybe not.

Question: If you look at lymphoid tissue only for diagnosing CWD, you're going to miss a few. If there are several different route of infection, one of them could be straight to the nerve in heavy doses.

Dr. Bartz: The last think I want to touch upon is interspecies transmission. What are the outcomes of inter-species transmission? First, it cannot convert the host PRPC. There's no infection, no clinical disease. End of story. The second thing that can happen is the agent can convert the host PRPC and you get clinical disease. Or the agent can convert host PRPC and there's no clinical disease, and this is persistence.

I'm going to start with the occurrence of clinical disease and break this up into two parts. What is the species barrier effect? An example is if you take mink that have transmissible mink encephalopathy and do an IC inoculation into the same host species, the incubation period is four months. But if you go into a new host species, this time the ferret, and do an IC inoculation, you get a huge extension of the incubation period of 28 to 30 months. The mink and ferret are both mustalids and differ by only two amino acids.

When you keep passaging the TME in the same host species—the ferret, eventually you see a shortening of the incubation period and eventual stabilization of the agent for the new host species. I break down the species barrier effect into two components. The first is the inter-species transmission and the second is adaptation of the agent for the new host species.

One way to look at the species barrier effect is a technique called cell-free conversion. This technique was developed in Byron Caughey's lab at NIH. It takes PRPC that's radio-labeled and growing tissue culture. You purify it and incubate it with brain-derived PRPSC, and when you co-incubate these two molecules, if the PRPSC can convert the radio-labeled PRPC to a PK resistant form, when you put this onto a piece of film, the only thing that should be radioactive is the converted radioactive PRPSC, which is proteinase-K sensitive to a PK-resistant form.

We know that PRPC is resistant to proteinase-K digestion. When you treat PRPSC with PK, it all goes away. If you incubate the radio-labeled mouse PRPC with mouse PRPSC, you'll get mouse PRPSC converting the mouse PRPC to a PK-resistant form. What's nice about this system is that you can use it to start to ask questions. What is important between the host PRPC and the agent PRPSC as far as inter-species transmission? This example uses hamster PRPSC. We know that if you inoculate hamster PRPSC into mice, there are no clinical signs. If you take hamster PRPSC, incubate it with the radio-labeled mouse PRPC, and treat it with proteinase-K, consistent with the biological properties, there's no conversion.

Now you can use this methodology and map out areas of PRPC that are important for inter-species transmission. Hamster PRPSC cannot convert. When you start to use these different chimeras, you can use it to start to map out regions of the molecule that are important for interspecies transmission.

You can also use it to try to predict species barriers where you don't know where transmission data is. This is a paper from Raymond in 2000. Here you can take PRPSC from sheep Scrapie with a certain genotype and incubate it with radio-labeled PRPC of sheep with the same genotype, and that's said to be 100% conversion because we know it's the same PRPSC going by intra-species transmission. You can start doing modifications where you use different genotypes of sheep PRPC, and you get a reduction in conversion, and then you can go to different species. Here they looked at mule deer, white tail deer or elk. You get a reduction in conversion.

You can also look at human PRPC, and there's a very low conversion. This low conversion is thought to be consistent, at least in sheep and humans. Epidemiologically, there's no evidence of sheep Scrapie transmitting to humans. You can also use this to assess the transmission of the white-tail deer PRPSC again using PRPC from a mule deer or a white tail deer of the same genotype. You can start modifying the genotypes of either deer or elk PRPC, and you get either an increase or decrease in conversion. You can ask questions about converting bovine PRPC and human PRPC. You get these much-reduced abilities to convert in this assay.

This reduction in conversion, then, one would predict would correlate with the transmission studies if they were done.

Inter-Species Transmission

The host genotype is important in whether the host is susceptible or not. I want to talk about the subsequent transmissions in the same host species. Why are you getting a reduction in the incubation period and adaptation or the intra-species transmission? When you have PRPSC from one host species interacting with PRPC from another, you get conversion to PRPSC. But I don't think you always get just one prion strain. On this inter-species transmission, you can get multiple prion strains. Data to support this hypothesis comes from some work I did using transmissible mink encephalopathy where we took biologically-cloned transmissible mink encephalopathy agent and transmitted it into hamsters. The bottom line is when we took the single strain and put it into hamsters, we were able to get the hyper and drowsy strains out. On first interspecies transmission, incubation periods are very long and there's quite a range—219 days to 501 days. They ranged anywhere from 130 days out to over 600 days.

In passage line B, 219-day incubation period, PRPSC was similar to that of hyper TME. The second passage has a reduction to 67 _____________

[tape change]

On western blots, we can tell hyper and drowsy apart. Otherwise, you have to do lesion profiling. So this is a nice system for trying to work this out.

In this passage line A, this first inter-species transmission, PRPSC is like drowsy TME. Drowsy is clinically characterized by lethargy. Hyper is clinically characterized by hyper-excitability ataxia. When you passage this, if you passage it at a high titer, now you have mixture clinical signs but you also have PRPSC that looks like a mixture of both hyper and drowsy. By fourth passage, you get the emergence of hyper. If you passage this animal at a low titer, you can get the emergence of drowsy. What we think is going on here is that inter-species transmission of the single TME strain in hamsters produces at least the hyper and drowsy strains, and we think, depending on the ratio of the strains produced in this first inter-species transmission, will result in either the rapid emergence or a longer emergence of the prion disease.

Dr. Detwiler: How would you explain that biochemically?

Dr. Bartz: When PRPC is converted to PRPSC, it's misfolded. There have to be many different stable energy states for the misfolded protein. I would hypothesize that mink PRPSC, when it interacts with hamster PRPC, it can fold into several different stable PRPSC molecules. So initially you get the mink interacting with hamster, and then you get a strain produced. I think early on in those first few rounds of replication, whatever strain is produced is probably going to be the predominant one because it has a jump start on the rest of them. On this really complicated western blot, we are mixing hyper and drowsy at known ratios, and basically we can mimic these effects. So it really is the ratio of hyper/drowsy produced by interspecies transmission that's causing this sort of effect.

To summarize inter-species transmission, we have PRPSC interacting with the new host PRPC molecule to change it into PRPSC. We think that, in certain instances, multiple strains can be produced. Intra-species transmission results in competition between these strains and eventual emergence of a predominant strain. We think the initial ratio of strains is important and affects this whole passage history. Probably the replication properties of strains is important. We think that drowsy is the predominant strain produced, but hyper replicates so much faster, it has an advantage.

One really important thing I want to point out here is that strain properties can change upon inter-species transmission. Chronic wasting disease doesn't cause disease when you passage it in a hamster, but if you passage CWD into ferrets, and then take that ferret passage tissue, it can cause disease in hamsters. So inter-species transmission can expand the host range. Also, with the hyper and drowsy, the more hamster passages you do, if you back-passage the inoculum into mink, hyper loses pathogenicity for mink quite quickly, where drowsy retains pathogenicity for mink.

The important point I want to make is that, when you're assessing inter-species transmission and you do a transmission study and it's negative, you have to be careful in saying it's negative for the strains you looked at. With this example, it's clear you could take hyper TME, inoculate mink, and they don't come down with the disease, so you might assume hamster prions don't cause disease in mink. That strain doesn't. You have to be careful assessing negative transmission results based on what's known about the strain properties.

The last thing I want to talk about is persistence. This would be the case where PRPSC interacts with the host PRPC and you get really slow replication. The replication agent is so slow that the animal dies of old age before clinical signs can occur.

This study is from Rick Race at NIH, transmitting hamster PRPSC into mice. He collected animals post-infection out to 782 days. None of these animals had clinical signs of prion disease, which is consistent with everything we knew about this species barrier. But when he went back and looked for PRP residue in these animals, he couldn't detect hamster PRP residue, but in a few of these animals with very long times post-infection, he could detect mouse PRP residue.

When he did the second passage, into either hamsters or mice, clinical signs appeared in the second passage. The point is that first inter-species transmission may not cause clinical signs, but you still can get replication to agent that subsequently, when you passage it into the same host species, results in clinical signs of the disease.

In the cell-free conversion studies, hamster PRPSC could not convert mouse PRPSC. Every sort of assay has limitations. The cell-free conversion said it couldn’t replicate. It could, but it was so slow and so long that the assay could not detect them.

I think persistence is very important. If you have inter-species transmission occurring and it doesn't cause clinical disease, and if you take the tissue and keep feeding it to that same host species, you’re going to get amplification and potentially emergence of the disease.

Is PRPSC shed in the environment? I have no idea. Terry can talk about that. Does PRPSC survive in the environment? The studies on deer PRPSC have not been done, but if deer PRPSC behaves like any other PRPSC, yes it can survive in the environment. Can PRPSC reach a new host species? I don't know. If they share common pastures, it's a possibility. Can PRPSC get to the central nervous system? Clearly, cattle are susceptible to oral infection, so that's yes. Can deer PRPSC convert cattle PRPC to the host PRPSC? Self-reconversion experiments would say yes, but very inefficiently. But really, the gold standard is the transmission studies, and there are two of these ongoing right now. One is at the USDA at Ames, and this is intra-cerebral inoculation. They are susceptible to IC infections. This means that once the agent reaches the brain, it can cause disease, but obviously in the field, that's not the natural route. Beth Williams is doing some oral infection studies, but I'm not sure of the status of those.

Dr. Thornsberry: So what you’re saying is that, inter-cerebrally, we can get CWD/PRPSC conversion, but that has not occurred, to anyone's knowledge, in the natural route.

Dr. Bartz: Right. IC inoculation is used because it has a short incubation period. It only tells us that replication can occur once the agent reaches the brain.

Dr. Thornsberry: Let's hypothesize that I had some cattle on the eastern slope and they were in the same pasture with elk with CWD. If a cow had been exposed to the PRP Scrapie and it did develop disease four years later, would that look like BSE? Would there be a way to determine if it came from CWD?

Dr. Bartz: The IC studies in cattle indicate it does not look like BSE. The clinical signs of the IC/CWD cattle are more like downer cattle, and not aggressive. As far as finding the source of a bovine TSE, the gold standard is the lesion profile study where you take cattle tissue and inoculate it into mice with appropriate controls, wait until the mice come down, and do the lesion profiling.

Dr. Thornsberry: There were two cases in Japan, but they indicated that tissue was not classical BSE as seen in Europe. Have you heard anything about that?

Dr. Bartz: This is based on differences on migration and the glycoform ratio of PrPSc.

Dr. Detwiler: Canada based that question because the herd that that animal came from was in Saskatchewan, in an area with CWD. That was one of the questions they faced right off the bat: is this BSE or is this some kind of transmission from CWD-infected elk in the area? Not only the histological lesions were classic BSE lesions, but clinically it's very difficult because if you miss the other behavioral changes, which this owner did. It was someone who had been a catfish farmer. He missed the early signs. The animal presented to slaughter as a down animal, non-responsive. Clinically it looked like just a down cow, but they did send that on to the United Kingdom and they did do some comparison glycoform patterns. Those haven’t been validated, but at least on preliminary work, it looked like classical BSE.

The Japanese case was a 23-month-old which was born in October. Their scientists say the western blot pattern looked different. The most recent case, which was a 21-month-old, looked more like classic BSE. The Italian cases were older animals, 15 and 16 years of age. But is it methodology? Is it really standard? That has to be sorted out before too much can be said.

Dr. Bartz: Glycoform ratio is dependent on very technical matters, what antibodies you use, what detection system you use. Those have to be standardized before you can start comparing from one lab to another.

Dr. Detwiler: The Japanese used a western blot they'd developed in their lab. It can't be compared across laboratories.

Dr. Bartz: That's problematic.


Dr. Terry Spraker: Max asked me to give an overview of CWD and then talk about the research being done at CSU. CWD was first noticed in the Colorado Division of Wildlife pens in Ft. Collins. CWD in the literature was first said to be seen in captive deer pens in 1967. I remember being there and those deer pens weren't even built until 1968, so the early history of CWD is confusing, but CWD was at least seen in the very early 1970’s as far as I can remember.

Beth Williams verified that is was truly a spongiform encephalopathy in the deer. She and Stuart Young described CWD in deer and elk in Colorado and Wyoming. George Bear A big Game Biologist for the Colorado Division of Wildlife found a sick elk in Rocky Mountain National Park in 1981 and I posted it for him and it turned out to be a case of CWD. At that time, there was lots of interchange from the Colorado Division of Wildlife with the animals from Rocky Mountain National Park. They took animals from the deer facilities and released them into the park to study food habits, and brought the deer and elk back.

We found the first case in mule deer in 1984 about half a mile west of the Colorado Division of Wildlife deer pens. In 1985, we found the first case in white-tail deer in Loveland, about 30 miles south of Ft. Collins. There has in the past been a question whether CWD started in the CDOW deer pens or came from the wild. The man who built the deer pens in 1968 did put deer and sheep together. These animals were placed on starvation trials. He obtained the sheep from CSU. This is where this theory has come about that one biologist started CWD in the Colorado Division of Wildlife deer pens. He still has sheep today from the original group, and he's never had a case of scrapie. There is no real evidence that this was the start of CWD.

The other part of the history of CWD was when it was first found in captive elk in 1996. The man who had CWD in Canada has gotten elk from a place in South Dakota that had CWD for probably 10 years, but it was not diagnosed. The year after it was diagnosed in Canada, it was diagnosed on his farm in South Dakota. He claims he received deer from Colorado. So there is a fairly good link from deer and elk originally from Colorado and spreading northward.

The natural host for CWD is only three cervids: mule deer, elk and white-tail deer. Recently, CWD has been found everywhere north of Interstate 70 in Colorado. Now a case has been found south of I-70 and one in central Utah. We just looked at several deer from Mexico and those were negative. CWD has been found in wild populations in Wyoming, Nebraska, Wisconsin, Utah, South Dakota, New Mexico, and Illinois.

Dr. Thornsberry: I have a classmate who deals with the Wisconsin Department of Natural Resources, and he's done a lot of work with them on CWD. How did we get this hot pocket of CWD in Wisconsin? Did they trace that to somebody introducing it, or did it just show up?

Dr. Spraker: No one knows. People bring carcasses back to their homes. I've had calls from so many states and people want to know what to do with the carcass. One guy in Maine called me after he'd already thrown the carcass away. One person has taken six cases of CWD to British Columbia. The last couple he said he fed to the crabs—threw them in the ocean. There is a lot of movement of animals and lots of movement of animal parts. There was a big trade of Wisconsin deer that somehow went to Missouri and then were released in Texas.

Dr. Spraker: The captive herds are primarily in the same areas where there's lots of CWD in the wild. I'm sure there's some evidence that it goes both ways. What are some of the epidemiological observations? There is evidence of transmission of the disease in captive animals to wild and vice versa. In the wild, there's natural expansion.

Clinical signs include emaciation. These clinical signs are not manifested until the terminal aspects of the disease, so an animal might have the disease for two or three years without showing clinical signs. You'll see emaciation and occasionally you'll see hair loss. There are similarities to Scrapie, although you don’t get the weight loss with Scrapie.

The clinical signs are obvious only in the terminal stages. They are depressed and you'll find them lying down. If you approach them, they do not get up.

Dr. Thornsberry: Is the chronic weight loss due to lack of neural functions of the muscles, or is it due to being mentally affected and they just don’t eat?

Dr. Spraker: I don’t know. The rumens are always full, so they are eating right up to the end. Because of the olfactory system that's heavily hit in these animals, I think that, at least in the wild, they lose their sense of smell. Deer are very dependent on smell for which forages to eat. Prion is present in the retina, so their eyes are affected also.

Dr. Detwiler: In Ohio, we did see a wasting condition associated with sheep. I don't think anyone's ever done a study, but there also seems to be an association, at least in flocks, with the abomasal emptying disorder.

Dr. Spraker: We have looked at a few cases of this abomasal emptying syndrome in sheep. We check them for prion disease, because it looks like a classical manifestation of an unusual manifestation of scrapie. We've never been able to show anything. We see abomasal ulcers in deer, but never in elk. With captive deer, you see a slowing of the emptying of the rumen and the animals will drink a lot of water. A clinical sign in captive deer is the sloshing of the rumen when the animal would run.

One clinical sign deer will manifest is excessive salivation. We saw this early in animals in Estes Park. We see animals eating out of food bins, salivating into them, and then other deer would come and eat out of that same feeder. One possible transmission is through the saliva. But when you find the prion in the lymphoid tissue of the gut, it could easily go out the feces also. Excessive salivation is a common clinical sign in terminal cases.

This is a gross necropsy of a deer, fairly typical. You'll see there's no fat at all in this animal. This anterior ventral aspect of the apical lobe is pneumonic. This is typical of aspiration pneumonia and you see this in both elk and deer. It's most likely associated with innervation of swallowing. The animals have trouble swallowing and they'll aspirate food into the lung. Actually, one of the first cases of CWD in captive elk in the US was seen in 1995, a year before the cases found in Canada, and these pathologists in South Dakota missed three or four cases of CWD in elk because they saw the pneumonia and stopped there. This went to court. The elk rancher felt it cost him money because the pathologist missed it. The court ruled in favoroft the pathologist because it had not been diagnosed. The bottom line is that CWD has been missed because people have found pneumonia and have stopped the necropsy. When we see pneumonia in deer or elk, the first thing we think of is CWD.

The clinical signs and gross lesions in the elk are identical to the deer and white tail deer. The histological lesions are similar in all of these TSEs, at least in the ruminants where you have the vacuolization of neuropil cytoplasm, vacuolization of gray matter and the neurons, vacuolization within the neurons, and neural degeneration. You see plaques in a lot of these diseases. They’re not as florid as you see in humans. They are areas of accumulation of prion.

In the literature, you see absence of inflammation. I don't believe this anymore because of the proliferation of the glial cells. The early lesions you see with CWD are the vacuolization within the neuropil. The neurons look good and there's no evidence of neuronal degeneration.

The immunohistochemical stain has been helpful with CWD. At first we were using H&E to diagnose CWD and it was very difficult. With the advent of the antibodies made for scrapie, we showed that the CWD agent also stained with the scrapie agent.

Dr. Thornsberry: If it doesn't stimulate an immune response, how do you get an antibody to it?

Dr. Spraker: The antibody is made in a different animal like a mouse or rabbit, but most of these antibodies are made in cell cultures. The animals do make antibodies or the proteins from other hosts.

Dr. Thornsberry: So the statement that there's no immune response to it is not true.

Dr. Spraker: Deer do not make antibody to their own PRP, but if you put in one that's not recognized as self, it will make antibody. There are hundreds of antibodies made to PRP.

Dr. Thornsberry: So you get a hamster immunized against a deer prion. You're developing a hamster antibody to a deer prion. But you can’t develop a deer antibody to a deer prion.

Dr. Spraker: That's right. People take small segments of the prion and make a specific antibody for that amino acid sequence. This antibody is made for a six-amino-acid sequence. It's made in cell cultures. This antibody has worked very well.

Another boon was that, early on, we found lymphoid tissue being positive in deer and elk. This was an important finding. It was confusing at first. People have ingested deer that had positive lymphoid tissue and the brain being negative. At that time the positive lymphoid testing was quested by some agencies and it was considered not a valid test. Hundreds of people have ingested deer that had positive lymphoid tissues.

Katherine O'Rourke developed a third eyelid test in domestic sheep where they stained for the lymphoid tissue in the third eyelid. They can find positive follicles in the third eyelids of sheep and we've shown you can do this with the tonsils of deer. An article by Margaret Wild has shown you can diagnose CWD a couple of years before the animals come down with clinical signs by doing a tonsilar biopsy.

Dr. Detwiler: I think it's important to note the test could be negative or there could be lack of lymphoid tissue in the third eyelid. You see that especially in sheep. As they get older, it atrophies. So a negative is not definitive. But the positive is very significant. We shouldn’t undersell the fact that the third eyelid had added a new tool for us in the field and in the production side as well as the regulatory side so we can detect the disease in a live animal in the pre-clinical stage. We can get into flocks earlier and start to eliminate animals. It's very good for flock-screening and it's helped us identify flocks in an earlier timeframe. It's added diagnostic capability for us.

Dr. Spraker: Yes, that's very important. A negative test doesn't tell you anything, but a positive test tells you a lot.

Dr. Spraker: So far, we've found a couple of false positives with elk, but that's when we were playing with different techniques and not using PK. With the standard tests that have been published and used now, to my knowledge there have been no false positives. If you do not destroy all the PrP-cellular, you're going to get positive staining. These antibodies are made for the PrP-cellular, but part of the testing is that you are supposed to destroy all the PrP-cellular. There are several different ways of destroying the PrP-cellular.

Here's a suggested pathogenesis for CWD in the deer. I think we're just at the tip of the iceberg with pathogenesis. It appears, at least with deer and elk, there could be an ingestion of the prion. The prion does enter the Peyer's patches and some of this was shown by Christina Sirgudsen. I personally think there is an adaptive phase in the lymphoid tissue. It takes awhile to adapt, and then it goes, I think, up the vagal nerve. It enters the vagus nucleus and then there's an adaptation in the brain and then, after it adapts in the brain, it spreads throughout the brain fairly rapidly. Because of high prevalence of stainable PrP in the lymphoid tissue of the small intestines and colon, I wouldn’t be surprised if it does not go out through the feces and through the saliva because of the tonsil being so heavily infected. There is so much lymphoid involvement so close to the outside of the body. At least that's one way the prion may go out of the body.

The Research

I know only a little bit about what's happening with the Department of Wildlife. It's fairly well known that they're doing susceptibility trials with cattle. Beth Williams and Mike Miller are the two primary investigators on this. They have put 10 or 15 cattle in deer pens that have very high infections of CWD. With this, they're studying environmental contamination. I think Mike is putting some dead deer in certain areas and letting them rot and then later they'll put in other deer to see if they can feed in that area and come down with CWD. The problem with this is that we have so much CWD all around Fort Collins, it would be hard to determine the source. They're also doing a project feeding CWD material to mountain lions. This work is being done in Wyoming and Colorado.

At Ames, they've injected 13 cattle with CWD brain tissue. Five have died. The first three had some vague clinical signs. Prion was found in those cattle, but they had very little spongiform change. The author is Ahamir Hamir.

Dr. Lynn Creekmore is doing a project in Ft. Collins. She's with the National Center for Animal Health. She has purchased 20 fallow deer and has put them in one of the pens where there's a degree of CWD. They're being monitored. At the two-year mark, they show no evidence of CWD. It's a five-year study.

At CSU, there are three groups working. Ed Hoover is doing quite a bit of work on some of the pathogenesis. Barb Powers and I are doing some work with CWD and Mo Solomon in the Department of Environmental Health has done investigation into some of these ELISA tests.

Ed Hoover's graduate students showed that that oral transmission of CWD worked, and they found PRP in intestinal and cranial lymph nodes 42 days after ingestion. These were fawns that received five grams of the brain tissue. They've also done some work with dendritic follicular cells and they've shown that the B cells and the dendritic follicular cells play a part with recognition of prion. They’re also looking at normal location of cellular PRPC throughout the whole body of a deer.

They have a group of white-tail deer and they're going to look at transmission of saliva, feces and repeating the brain experiments, specifically seeing if saliva and feces and be used for transmission of CWD. They're using mule deer material going into white tail deer. I don't know how much of a species jump that's going to be. For all practical purposes, it doesn't look like there should be. Katherine O'Rourke has shown there's quite a bit of difference in the genetics of the PrP gene within white-tail deer and within mule deer.

Barb Powers is working with the Bio-Rad ELISA test. They did a tremendous amount of work last year in validating this test for elk and mule deer in Colorado. It was a political nightmare. Mo Solomon actually started it, doing comparison of Bio-Rad and Prionics. They took the tests that were used for BSE and tried to modify them to work with CWD. The people who produced Prionics and Bio-Rad sent their primary scientists to try to make the tests work. Bio-Rad was the better test of the two, so it was chosen for the extensive surveillance that happened last year that resulted in the validation of this test for CWD in the US for white tail, mule deer and elk. But it's only in the lymphoid tissue.

Dr. Detwiler: Since then, there have been two additional tests.

Dr. Spraker: The tests now are Idexx, validated for white tail deer, and VMRD, validated for white tail and mule deer. It's still only lymphoid tissue.

We found some of the first early cases and we showed that the captive animals and the wild animals had the same disease. That was a big question at first. We found you could not tell the difference between captive and wild mule deer when you looked at the lesions in the brain and at the patterns of lymphoid staining throughout the body.

We developed the IHC test with Katherine O'Rourke that's currently used throughout the US and Canada, and we mapped the prion in mule deer. These were all hunter-killed animals so the time of exposure for CWD was not determined. But we saw definite patterns of prion distribution. We had only the heads. When you do staining only in the tonsil and when you do serial sections of the brain, there's no evidence of prion in the brain.

Then we had an animal with a positive tonsil and a group that had prion only in the vagas nucleus. Then it would spread to the solitarius. What was odd was that the next area where the prion appeared was the hypothalamic region. We're starting to do this same mapping now in elk and the picture looks the same so far. The thing to notice here is that the cerebellum is not affected until the very end. I don't know how it is in sheep, but this is a characteristic we've seen in the deer.

When you're doing any kind of surveillance, if you used brain tissue, you have to get this vagas nucleus. If you don’t, you can miss a lot of the early cases.

We had a chance to work with the state and federal people when they were trying to eliminate CWD from the US and Canada. Between the US and Canada, 12,000 to 14,000 ranch elk were killed. We looked at a lot of the animals. We wanted to look for patterns and also compare the stainability of the lymphoid tissue, because in deer, it seems consistent that the lymphoid tissue was affected with the brain and you would have early cases where you'd have lymphoid staining and no brain staining. In mule deer, we found one case where there was staining in the brain and not staining in the lymph nodes. I think they've also found that in sheep, and we've found a little more of that in elk.

For all this testing we've used IHC. Two different machines are used —the Nexus and the Benchmark. We've used the antibody produced by Katherine O'Rourke. I know this antibody is being produced by VMRD and it's sold, but we have not had very good luck with this commercial antibody.

These are some of the different stages in the elk. We're starting the map the whole brain, so you may be able to look at one section to obex and predict where the prion is in the rest of the brain. A grade one is a negative animal and a grade two is an animal that had negative staining in the brain but positive lymphoid tissue. Grade three is where you may or may not have lymphoid staining, but you have what we call a one-plus staining in the obex. The first area you see affected is the lateral aspect of the middle third of the vagas. In cattle, one of the first areas to be affected is the solitarius nucleus. Another very important difference between BSE and CWD is that we would miss probably 30 to 40% of the cases if we did not use IHC. From what I'm told, with BSE, the immunostaining is not as good in cattle as it is in deer and elk. You can do very well with good H&E sections.

With elk, you see very little intra-nuclear staining, whereas with cattle, you see much more intra-nuclear staining of the prion.

A grade four means that the vagas nucleus is mostly affected. A brain plus three means it's filling the nucleus and the solitarius and it's beginning to spill out into some of the other nuclei. At this stage, the rest of the brain will begin to have prion in it.

We've found that the redex is the vagas is affected later than the nucleus, so the prion accumulates in the nucleus before you can see it in the redex of the vagas. The redex of the vagas is the conduit of nerves coming in and out.

With this grading of elk, we have a variance of CWD staining in the lymphoid tissue. It's not as neat as it is in deer. Even in the more terminal stages, we found a couple of elk that did not have staining. Some of this may be due to not cutting enough lymphoid tissue, but we've really looked at some of these animals and we have not been able to verify immunostaining in these lymphoid tissues. It's not as clean as it is in white tail deer.

We're trying to map the rest of the elk brain and do the same thing with white tail deer, and them compare them to what a single section of the obex would be. Also, we have a project looking at some of the micronutrients —copper, manganese, molybdenum, selenium and zinc—and seeing if that correlates with CWD. We're also looking at lymphoid tissue in really early cases of CWD.

Fear Factor

Another problem that has come up because of the rampant fear factor in the US and in Europe is disposal of carcasses, tissues, and reagents that have come in contact with TSE. In some places, you can't even think about using landfills to dispose of carcasses if they have CWD or Scrapie. At CSU, we have a sodium hydroxide digester that brings the temperature up to 300°F with 60 pounds of pressure, and you cook this material for six to right hours. This digester cost about a half a million dollars and we've sunk more money into it. Disposal is a big problem. Some communities have hampered the building of incineration facilities with the claim you can get CWD by breathing the air. These thoughts are being propagated and causing us a tremendous amount of trouble.

Dr. Detwiler: Even when you do non, do you still get an odor from the digester?

Dr. Spraker: Yes, especially when you dump it. If you put it into the sewer, it's okay. But our city charges for BOD (biologic oxygen demand). So it costs us $3000 to $4000 a month to dump it in the sewer, and they just came up with a half a million dollar surcharge for having the privilege to dump it. We can't afford it, so we've tried to make a dehydrator. The fragrance of the high ammonia escapes.

The rendering companies in Ft. Collins are going out of business. We were forced to go somewhere and incineration was very difficult, so we went to this system.

Dr. Bartz: Is the operating cost high?

Dr. Spraker: No, it's really not. But you have to take into account all the other problems.

This is the big question. This is the hypocrisy of this disease. We've had to reconvert all these buildings to make them where all the water goes into the digester because we couldn’t let it go down the sewer any more.

Dr. Detwiler: Was this EPA's idea?

Dr. Spraker: That's where it first started, yes.

Dr. Bartz: The digester is just for CWD-infected tissue?

Dr. Spraker: It's for TSE, Scrapie and CWD.

Dr. Bartz: What about rodents?

Dr. Spraker: If it's a TSE, it has to go in here, yes. This is the only way we dispose of animals now, but it's mandatory if it's a TSE—even gloves.

This is data we have to date. People ask Can humans get CWD? You never say never, but this is what we've seen so far: humans have been heavily exposed by handling and consuming CWD-positive deer and elk for the minimum of 35 years. I don't even want to think about how many deer we consumed from the deer pens when I was a graduate student.

This is very important: Prusiner says it and others have, too—that CWD can go to human and there's just not been enough exposure yet. This is my opinion: in Britain, when a cow had BSE it was ground up and diluted and spread. When a hunter kills a deer or elk with CWD, the immediate family eats the deer. They're exposed for a year. Most people take a year and a half to eat an elk. So if CWD is going to go to people, those people would have a high exposure rather than a diluted exposure. Exposure to brain is there, as some of these people do brain tanning. To date, there have been no unusual neuro-degenerative diseases found in people, and they have looked.

The fear factor is unreal. I had a man come to the office in a panic, and he was sincere. He said he'd gotten some drops of blood on his pickup from a deer that came from the CWD area. He thought the back of his pickup was contaminated. He asked if he should sell his pickup

Another man came in with a deer to dispose of it, and he knew it was positive, but when he looked at it, he decided to take it home.

I had a case where a hunter had shot an elk or deer and Game and Fish called and got his wife and told her the deer had CWD. The next day they had a party and fed the deer to their guests. A nasty divorce was going on, and after the party, the wife told her husband about the CWD. This was a group of MDs. As of now, all of them are fine.

Dr. Detwiler: If someone calls you and says he has a known positive animal and wants to know if he should eat it or not, what would you tell him?

Dr. Spraker: I'd tell him "no." I've thrown away a deer and an elk and I hated to do it, but I would not knowingly eat it. I'm not afraid to go and hunt in that area and test, but the test will miss early cases.

Dr. Bartz: Do you have an estimate of the numbers of people you think have been exposed?

Dr. Spraker: No, but I can tell you this year they found 200 positive deer and elk. On a smaller scale, just in Colorado, we’d average 100 to 125 positive cases of CWD. But no testing was done in these other states. A lot of people have eaten these deer for a long time, and they have gone throughout the United States. There have been claimed cases of hunters having CWD, but they were all other conditions.

Dr. Keller: The cause of death is not always known when people die of neuro-degenerative disease.

Dr. Spraker: Yes, but right now they are really paying close attention to that.

Dr. Detwiler: After being hammered by the public health community that we don’t test nearly enough cattle, they still ask how many full brains really get done. The human community does not do a systematic look at brains of neuro-degenerative diseases.

Dr. Keller: Animal health agencies are being encouraged to determine prevalence of CWD in cervid populations.

Dr. Spraker: But if we had this much CWD in this small of an area and this many people consumed it, I think they would have picked up something. Something would have spiked up. So far there's been no unusual incidence of any kind of clinical neuro-degenerative condition.

Dr. Thornsberry: Dr. Bartz, hearing that from Dr. Spraker, what is an explanation? You've probably done the studies to show that these prions are in the muscle tissue as well.

Dr. Bartz: Prions or PrPSc have been detected in muscle homogenates from prion-infected mink (Marsh et al., 1969), hamsters (Bartz et al., 2002, Thormzig et al., 2003) and humans (Glatzel et al., 2003). Additionally, immunohistochemical data has shown PrPSc to be associated with myocytes in humans with CJD (Kovacs et al., 2004) and in prion-infected hamsters (Mulcahy et al. from the lab of Dr. Richard Bessen, Journal of Virology in Press). It is still unclear if prions replicate in muscle cells, but the presences of PrPSc in muscle cells suggests that prion infectivity and PrPSc that is detected in muscle homogenates is not entirely from innervation of the muscle tissue.

Dr. Thornsberry: What would be an explanation to having that kind of exposure to prions and not developing into a Scrapie-type prion that we call disease?

Dr. Spraker: I don’t know, but I know people have consumed it.

Dr. Thornsberry: Fox news reported on a military man stationed in the Middle East who consumed the traditional breakfast in those Moslem countries—sheep brains scrambled with eggs. He's not be diagnosed with Creutzfeldt-Jakob type disease. They're trying to get military pay for him because of hazard of duty. They think he picked this prion up from Scrapie-infected sheep or goats, not cattle. Yet we know that the ability of that to go to humans is supposed to be minimal. Why are there not outbreaks all through the Middle East of Creutzfeldt-Jakob disease?

Dr. Spraker: We ship a lot of sheep brains over there. It's a complex situation.


James Alford _was_ diagnosed with CJD, and it was confirmed, see ;

Friday, August 22, 2008

Creutzfeldt Jakob Disease and Veterans and how they are treated at death

Friday, August 27, 2010


Thursday, August 19, 2010

SCRAPIE CANADA UPDATE Current as of 2010-07-31 The following table lists sheep flocks and/or goat herds confirmed to be infected with scrapie in Canada in 2010.

Current as of: 2010-07-31

Journal of Neurology Volume 226, Number 3, 219-220, DOI: 10.1007/BF00313385 Letter To The Editor

Inherited susceptibility, ovine brain consumption and Creutzfeldt-Jakob disease (CJD)

E. Mitrova and Vlastimil Mayer

I Research Institute of Preventive Medicine, 809 58 Bratislava

2 Institute of Virology, Slovak Academy of Sciences, 80939 Bratislava, Czechoslovakia

To The Editor:

The source of infection and the mechanism by which Creutzfeldt-Jakob disease spreads remain unknown [1-4]. There is evidence that susceptibility to CJD may involve genetic factors [5-7]. On the other hand, an hypothesis was advanced that CJD may be etiologicalIy related to scrapie in sheep [1,8,9]. According to the latter view, contamination with the scrapie agent during handling and/or ingestion of scrapied sheep tissues, especially brain, may initiate the infection. A contamination with infected brain through handling or consumption is postulated for kuru. Indeed, the elimination of cannibalism in connection with primitive burial ceremonies [1], has been associated with a decline in kuru.

We offer additional observations bearing on the hypothesis that CJD, in certain cases, may have a zoonotic origin perhaps combined with an innate tendency to CJD.

In a geographically limited are of Slovakia and adjacent Hungary, eleven neurohistologically confirmed cases of CJD have been observed over a few years [4]. Two of the eleven were blood relatives and, in addition raised, slaughtered, and ate sheep including brain.

Case Reports

A 55-year-old woman died in 1975 after a 3.5 months illness including neurological signs. A flu­like febrile illness preceded the neurological deterioration. Microscopic sections of the brain examined at necropsy showed the typical spongiform encephalopathy attributed to CJD. From early childhood, she had lived on a farm on which five to seven sheep were always maintained. The animals were periodically slaughtered by her and other family members. The meat, viscera and fresh brains were consumed. Brains were mixed with scrambled eggs.

* Corresnondins author


Mutation of the prion protein in Libyan Jews with Creutzfeldt-Jakob disease Article Abstract:

Creutzfeldt-Jakob disease (CJD) is a neurodegenerative disease of a class referred to as the spongiform encephalopathies. The disease can be transmitted experimentally and has also been transmitted accidentally. The causative agent in these transmissions is unlike any well characterized infectious agent and is referred to by many as a prion. Creutzfeldt-Jakob disease may occur in families, but is usually sporadic. The incidence of Creutzfeldt-Jakob disease is about one or two cases per million people. However, among Jews from Libya, the incidence is 100 times higher. Many possible explanations have been put forward to account for this unusually high incidence, but none has sustained any scrutiny. One of the more popular notions was that the eating of sheep brains, a popular delicacy in the region, infected people with scrapie, a prion disease of sheep similar to CJD. However, the eating of sheep brain is popular throughout the Mediterranean, and cannot explain the specificity of the increased incidence to Libyan Jews. Mediterranean sheep, if anything, have a lower rate of scrapie than other areas of Europe and North America. A study was undertaken to determine if the increased incidence of CJD among these people might be accounted for by genetic factors. The prion protein genes were analyzed in 11 Libyan Jews with Creutzfeldt-Jakob disease. Investigation of one patient revealed that a mutation had occurred in the 200th codon of the gene, that is, the 200th set of three DNA bases. The net result of this change would be to substitute a lysine for glutamine in the resulting protein. After this mutation was identified, it was confirmed in the other 10 Libyan patients. It is interesting to note that the mutation was not present in a Moroccan Jew with CJD. The results suggest that the increased incidence of Creutzfeldt-Jakob disease in this population is the result of a gene carried by this group. In eight of the present cases, a family history of CJD could be confirmed. Although not all families were cooperative in providing information of the ancestral heritage, all the families for which such information was available could be traced to Djerba, which is an island off the coast of Tunisia. (Consumer Summary produced by Reliance Medical Information, Inc.)

author: Scarlato, Guglielmo, Prusiner, Stanley B., Hsiao, Karen, Meiner, Zeev, Kahana, Esther, Cass, Carin, Kahana, Irit, Avrahami, Dana, Abramsky, Oded, Gabizon, Ruth Publisher: Massachusetts Medical Society Publication Name: The New England Journal of Medicine Subject: Health ISSN: 0028-4793 Year: 1991

Genetic aspects, Mutation (Biology), Mutation, Creutzfeldt-Jakob disease, Spongiform encephalopathy, Nervous system diseases

Read more:

Abstract Format Summary


Medicine (Baltimore). 1997 Jul;76(4):227-37.

Familial Creutzfeldt-Jakob disease. Codon 200 prion disease in Libyan Jews. Meiner Z, Gabizon R, Prusiner SB.

Department of Neurology, University of California San Francisco 94143, USA.

Abstract Creutzfeldt-Jakob disease (CJD) is the most prevalent of the human prion diseases, a group of fatal neurodegenerative disorders afflicting both humans and animals. The unique characteristic of these diseases, whether sporadic, dominantly inherited, or acquired by transmission, is the accumulation in the brain of an abnormal isoform (PrPSc) of the cellular prion protein (PrPc). Progress has been made in understanding inherited prion diseases by genetically linking clusters of familial CJD (fCJD) to mutations of the PrP gene (PRNP). One of the largest clusters of fCJD exists among Jews of Libyan origin. The clinical and pathologic manifestations of CJD in this community resemble those seen with sporadic CJD (sCJD), but the incidence is about 100 times higher than in the general population. Initially, this high incidence was attributed to infection via consumption of sheep brains or eyeballs, but a mutation at codon 200 in PRNP resulting in the substitution of lysine (K) for glutamate (E), designated E200K, was identified in this population. The onset of fCJD (E200K) is age dependent and shows nearly complete penetrance by age 85 years. fCJD in Libyan Jews is invariably associated with accumulation of the pathologic isoform PrPSc in the central nervous system. Using mutation-specific antibodies, it was shown that most PrPSc in the brain of these patients originated from the mutant protein. Some studies suggest that mutant PrP may accumulate in brain and other organs due to an impaired degradation, and its accumulation has been postulated to promote conversion into PrPSc. fCJD (E200K) has been transmitted to primates and transgenic mice, highlighting the need to address ethical and public health issues surrounding the possibility of human to human transmission.

PMID: 9279329 [PubMed - indexed for MEDLINE]

Original Articles

Creutzfeldt-Jakob disease and sheep brain a report from central and southern Italy

F. Lo Russo, G. Neri and L. Figà-Talamanca

Abstract The places of origin of 7 out of 8 patients with CJD coincide with the distribution of sheep-rearing in central and southern Italy, confirming the suggested link between this disease and eating and-or handling sheep CNS tissue. Since 6 of the 8 cases were women, it seems more likely that the virus responsible for CJD enters the body through a break in the skin of the hands and forearms in the process of foodhandling rather than via the Digestive tract. This aspect should be borne in mind when investigating the problems of CJD transmission. È stata studiata la distribuzione geografica dei luoghi di origine di 8 pazienti con CJD correlandola alla distribuzione, all'interno delle diverse regioni dell'Italia Centrale, e in parte Meridionale, delle aree a prevalente economia da pascolo, soprattutto pastorizia ovina. Si è indagata una eventuale connessione tra abitudini alimentari che comprendono la manipolazione a scopo alimentare ed il susseguente consumo di tessuti del SNC di ovini e la insorgenza della CJD. Viene avanzata la ipotesi che attraverso soluzioni di continuo nel rivestimento dei tegumenti delle estremità superiori, piuttosto che per la via della ingestione, l'agente virale della malattia potrebbe penetrare nell'organismo, per cui questo elemento sarebbe da tenere presente nell'affrontare i problemi connessi con le modalità di trasmissione della CJD. Key-Words Creutzfeldt-Jakob Disease - Sheep Brain - Sheep Rearing - Fondhandling

European Journal of Epidemiology Volume 7, Number 5, 520-523, DOI: 10.1007/BF00143133 “Clusters” of CJD in Slovakia: The first laboratory evidence of scrapie E. Mitrová, S. Huncaga, G. Hocman, O. Nyitrayova and M. Tatara

European Journal of Epidemiology © 1991 Springer.

Abstract Epidemic-like occurrence of Creutzfeldt-Jakob disease was observed in 1987 in Slovakia (Orava). Search for the cause of CJD focus indicated a concidence of genetic and environmental risks in clustering patients. Since Spongiform Encephalopathies might be transmitted orally, (Bovine Spongiform Encephalopathy), the possibility of zoonotic source of CJD cases in Orava was also considered. A deficient knowledge about the occurrence of scrapie in Slovakia stimulated an examination of sheep with signs of CNS disorders in two flocks of Valasky breed in Orava. In one flock, neurohistopathological examination revealed in sheep brains lesions characteristic for scrapie. Frozen brain tissue of these animals were used for the detection of scrapie associated fibrils. They were found in 2 animals from the same flock. This is the first laboratory confirmation of scrapie in Czecho-Slovakia. The possible epidemiological and economical implications are emphasized.

Peiffer, J. : Gerstmann-Straussler's disease, atypical multiple sclerosis and carcinomas in a family of sheepbreeders. Acta Neuropath. 56: 87-92, 1982. Peiffer (1982) described a family of sheepbreeders in which a father and 2 sons had GSS. All 3 also had congenital hip dysplasia, as did at least 3 other members of the kindred, all females. Atactic symptoms, dysarthria, and personality changes characterized the clinical course of this disorder, which might be labeled atypical multiple sclerosis. Like CJD , GSS is a form of subacute spongiform encephalopathy. Cases of GSS are clinically similar to the atactic type of CJD. Although there are many neuropathologic similarities, GSS differs from CJD by the presence of kuru-plaques and numerous multicentric, floccular plaques in the cerebral and cerebellar cortex, basal ganglia, and white matter. Whereas only 5 to 15% of CJD cases are familial, most cases of GSS are familial.

Neuroepidemiology. 1985;4(4):240-9.

Sheep consumption: a possible source of spongiform encephalopathy in humans. Davanipour Z, Alter M, Sobel E, Callahan M.

Abstract A fatal spongiform encephalopathy of sheep and goats (scrapie) shares many characteristics with Creutzfeldt-Jakob disease (CJD), a similar dementing illness of humans. To investigate the possibility that CJD is acquired by ingestion of contaminated sheep products, we collected information on production, slaughtering practices, and marketing of sheep in Pennsylvania. The study revealed that sheep were usually marketed before central nervous system signs of scrapie are expected to appear; breeds known to be susceptible to the disease were the most common breeds raised in the area; sheep were imported from other states including those with a high frequency of scrapie; use of veterinary services on the sheep farms investigated and, hence, opportunities to detect the disease were limited; sheep producers in the area knew little about scrapie despite the fact that the disease has been reported in the area, and animal organs including sheep organs were sometimes included in processed food. Therefore, it was concluded that in Pennsylvania there are some 'weak links' through which scrapie-infected animals could contaminate human food, and that consumption of these foods could perhaps account for spongiform encephalopathy in humans. The weak links observed are probably not unique to Pennsylvania.


If the scrapie agent is generated from ovine DNA and thence causes disease in other species, then perhaps, bearing in mind the possible role of scrapie in CJD of humans (Davinpour et al, 1985), scrapie and not BSE should be the notifiable disease. ...

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Sunday, April 18, 2010


see below

> Agussi is beginning to think that sporadic CJD is from sheep, but he doesn't have evidence.


Dr. Spraker: We ship a lot of sheep brains over there. It's a complex situation.

I think CWD is a unique spongiform encephalopathy. Whether it came from sheep or a spontaneous mutation, I don’t know. At the time, there's no evidence it can be naturally transmitted to any of these animals. If CWD is found to be naturally transmitted to cattle or sheep, there's going to be a lot of change.

Dr. Thornsberry: We do know you can give an intra-cranial injection of this prion and cause lesions? They've documented that. But what about intense natural exposure like the eating of elk placenta or the licking of an elk carcass?

Dr. Spraker: When you have captive animals, you see a lot higher incidence of CWD than in any wild population. A man in Nebraska fenced in some white tail deer, and they ended up killing them and 52% had CWD. When you concentrate them, whatever way they transmit it, you're going to have a lot higher incidence. This is one of the reasons they're killing so many deer, thinking they're going to reduce the number of animals and thus reduce the incidence of the disease. They'll never take it away.

Dr. Thornsberry: Is there a high prevalence of prions in placental tissues?

Dr. Spraker: We've had several elk and several deer that died of terminal CWD that were pregnant. We've not been able to demonstrate PRP in the placenta or any of the fetal tissues with IHC or with Bio-Rad. We can demonstrate IHC in the placentones of domestic sheep. A man out of Katherine O'Rourke's lab has a nice article on demonstrating PRP in the placenta, and Race has an article about finding PRP in the placenta and showing how the PRP of the placenta has different glycoforms than the PRP of the brain. In sheep, they've definitely shown that. For a long time, they said that Scrapies transmitted from the ewe to the lamb during lambing, but it does not go trans-placentally. But this does not seem to occur in elk and deer.

Dr. Detwiler: the important thing with sheep is not only PRP, but they've actually correlated the PRP detection of infectivity with detection of PRPSC, which added on to Patterson's work back in the sixties. In sheep they actually fed placenta to goats and caused the disease by oral ingestion of the placenta from Scrapie-infected animals.

Dr. Spraker: I'm trying to get some money to do that with deer because I have some sheep placentas.

Dr. Thornsberry: So to summarize, you do not believe, in the data you've examined and your experience in pathology, that there is much risk of transfer of CWD from a cervid to a bovine.

Dr. Spraker: There's been no evidence, but I haven't done any of that work.

Dr. Thornsberry: They're saying,”Is the prion going to be there forever?”

Dr. Spraker: That's the concern that some people are voicing about this. It's been a hot topic.

Dr. Spraker: There's been a project started by Jim Voss and Dan Guald. They talked a group of ranchers living within the enzootic area for CWD into turning in all the heads of their cull cows. The cattle came from enzootic areas for CWD. They had about 270 culled cows that had been in contact with deer from six to 12 years. They did histopath and IHC on these cattle and all were negative for any evidence of a TSE.

Dr. Thornsberry: With that knowledge, where in the world are these BSE cases coming from? Is this spontaneous generation theory going to hold up? If that's possible, then you should be able to get BSE anywhere in the world.

Dr. Spraker: They say that 85% of the CJD cases fall into the sporadic category. That means they cannot find any evidence of a source of the disease. Agussi is beginning to think that sporadic CJD is from sheep, but he doesn't have evidence. If that's the case, why don’t Australia and New Zealand have sporadic CJD? As far as I understand, with the sporadic cases, there's a deterioration or a degeneration of the prion that weakens some of the links and it turns or it changes its configuration.

Dr. Thornsberry: We were shown data that brain tissue heated to 600°C was still infectious.

Dr. Spraker: To me it's easier to think maybe it's associated with a metal and it comes alongside and causes the normal prion to change.

Dr. Thornsberry: We've established pretty well that CWD probably is not infecting cattle. It's probably not infecting humans. But we have established that it's very infective with deer and elk, and it’s a problem. Whatever transmission is taking place, it is infective. It is a dangerously infective prion within the species that it's established in. And yet we keep hearing this information, as veterinarians, that BSE is not infective. It's a terminal disease. The animal gets it and dies. We know that's not the case with many of these prion diseases.


These observations suggest striking differences in the ß-sheet alignment of PrPSc aggregates between prion-infected 170S and 170N animals and may provide a plausible starting point for clarifying the structural basis of prion species barriers that are highly relevant to public health, including the potential transmissibility of bovine and cervid prions to humans.

<<< As a possible exception to these observations, cattle may be susceptible to CWD from white-tailed deer (86). The latter finding suggests that specific prion strains can overrule the codon 170 homology requirement. <<<

This is not good either, considering that BSE, Scrapie, CWD, and CJD, all have mutated in North America. ...TSS

Monday, June 14, 2010

A molecular switch controls interspecies prion disease transmission in mice

please see full text ;

Susceptibility of Cattle to First-passage Intracerebral Inoculation with Chronic Wasting Disease Agent from White-tailed Deer

A. N. Hamir1, J. M. Miller1, R. A. Kunkle1, S. M. Hall2 and J. A. Richt1 + Author Affiliations 1National Animal Disease Center, ARS, USDA, Ames, IA 2Pathobiology Laboratory, National Veterinary Services Laboratories, Ames, IA Dr. A. N. Hamir, National Animal Disease Center, ARS, USDA, 2300 Dayton Avenue, PO Box 70, Ames, IA 50010 (USA). E-mail:


Fourteen, 3-month-old calves were intracerebrally inoculated with the agent of chronic wasting disease (CWD) from white-tailed deer (CWDwtd) to compare the clinical signs and neuropathologic findings with those of certain other transmissible spongiform encephalopathies (TSE, prion diseases) that have been shown to be experimentally transmissible to cattle (sheep scrapie, CWD of mule deer [CWDmd], bovine spongiform encephalopathy [BSE], and transmissible mink encephalopathy). Two uninoculated calves served as controls. Within 26 months postinoculation (MPI), 12 inoculated calves had lost considerable weight and eventually became recumbent. Of the 12 inoculated calves, 11 (92%) developed clinical signs. Although spongiform encephalopathy (SE) was not observed, abnormal prion protein (PrPd) was detected by immunohistochemistry (IHC) and Western blot (WB) in central nervous system tissues. The absence of SE with presence of PrPd has also been observed when other TSE agents (scrapie and CWDmd) were similarly inoculated into cattle. The IHC and WB findings suggest that the diagnostic techniques currently used to confirm BSE would detect CWDwtd in cattle, should it occur naturally. Also, the absence of SE and a distinctive IHC pattern of CWDwtd and CWDmd in cattle suggests that it should be possible to distinguish these conditions from other TSEs that have been experimentally transmitted to cattle.

second passage is even worse ;

Experimental Second Passage of Chronic Wasting Disease (CWDmule deer) Agent to Cattle

A. N. Hamir, R. A. Kunkle, J. M. Miller, J. J. Greenlee and J. A. Richt Agricultural Research Service, United States Department of Agriculture, National Animal Disease Center, 2300 Dayton Avenue, P.O. Box 70, Ames, IA 50010, USA


To compare clinicopathological findings in first and second passage chronic wasting disease (CWDmule deer) in cattle, six calves were inoculated intracerebrally with brain tissue derived froma first-passageCWD-affected calf in an earlier experiment. Two uninoculated calves served as controls. The inoculated animals began to lose both appetite and weight 10–12 months later, and five subsequently developed clinical signs of central nervous system (CNS) abnormality. By 16.5 months, all cattle had been subjected to euthanasia because of poor prognosis. None of the animals showed microscopical lesions of spongiform encephalopathy (SE) but PrPres was detected in their CNS tissues by immunohistochemistry (IHC) and rapid Western blot (WB) techniques. Thus, intracerebrally inoculated cattle not only amplified CWD PrPres from mule deer but also developed clinicalCNSsigns in the absence of SElesions.This situation has also been shown to occur in cattle inoculated with the scrapie agent. The study confirmed that the diagnostic techniques currently used for diagnosis of bovine spongiformencephalopathy (BSE) in theUS would detect CWDin cattle, should it occur naturally. Furthermore, it raised the possibility of distinguishing CWDfromBSE in cattle, due to the absence of neuropathological lesions and to a distinctive multifocal distribution of PrPres, as demonstrated by IHC which, in this study, appeared to be more sensitive than the WB technique. Published by Elsevier Ltd. Keywords: cattle; chronic wasting disease (CWD); deer; transmissible spongiform encephalopathy (TSE)



CWD, like all other TSEs, is characterized by a long incubation period, which in deer is seldom less than 18 months (Williams and Young, 1992). In an experimental study of cattle inoculated intracerebrally with CWD from mule deer (first passage), amplification of PrPres was demonstrated in only five of 13 (38%) cattle, after incubation periods that ranged from 23 to 63 months (Hamir et al., 2001a, 2005a). In contrast, all inoculated cattle in the present study were positive for PrPres within 16.5 months. This increased attack rate with shorter incubation periods probably indicates adaptation of the CWDmule deer agent to a new host.


The uniform susceptibility, relatively short incubation, and absence of microscopical lesions in cattle given CWD brain material passaged once through cattle resembled findings in cattle inoculated intracerebrally with the scrapie agent (Cutlip et al., 1997). In that experiment, 100% of cattle died 14–18 months after inoculation with material from the first cattle-passage of a US strain of the scrapie agent; none showed microscopical lesions and all were positive for PrPres.


Infection Studies in Two Species of Non-Human Primates and one Environmental reservoir infectivity study and evidence of two strains

Thursday, April 03, 2008

A prion disease of cervids: Chronic wasting disease

2008 1: Vet Res. 2008 Apr 3;39(4):41

A prion disease of cervids: Chronic wasting disease

Sigurdson CJ.


*** twenty-seven CJD patients who regularly consumed venison were reported to the Surveillance Center***,


full text ;

From: TSS (


Date: September 30, 2002 at 7:06 am PST

From: "Belay, Ermias"


Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"

Sent: Monday, September 30, 2002 9:22 AM


Dear Sir/Madam,

In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD. That assumption would be wrong.

I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091). Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.

Ermias Belay,

M.D. Centers for Disease Control and Prevention

-----Original Message-----


Sent: Sunday, September 29, 2002 10:15 AM

To:;; ebb8@CDC.GOV


Sunday, November 10, 2002 6:26 PM



A. Aguzzi - Chronic Wasting Disease (CWD) also needs to be addressed. Most serious because of rapid horizontal spread and higher prevalence than BSE in UK, up to 15% in some populations. Also may be a risk to humans - evidence that it is not dangerous to humans is thin.


Chronic Wasting Disease and Potential Transmission to Humans

Ermias D. Belay,* Ryan A. Maddox,* Elizabeth S. Williams,? Michael W. Miller,? Pierluigi Gambetti,§ and Lawrence B. Schonberger* *Centers for Disease Control and Prevention, Atlanta, Georgia, USA; ?University of Wyoming, Laramie, Wyoming, USA; ?Colorado Division of Wildlife, Fort Collins, Colorado, USA; and §Case Western Reserve University, Cleveland, Ohio, USA Suggested citation for this article: Belay ED, Maddox RA, Williams ES, Miller MW, Gambetti P, Schonberger LB.

Chronic wasting disease and potential transmission to humans.

Emerg Infect Dis [serial on the Internet]. 2004 Jun [date cited]. Available from:

Chronic wasting disease (CWD) of deer and elk is endemic in a tri-corner area of Colorado, Wyoming, and Nebraska, and new foci of CWD have been detected in other parts of the United States. Although detection in some areas may be related to increased surveillance, introduction of CWD due to translocation or natural migration of animals may account for some new foci of infection. Increasing spread of CWD has raised concerns about the potential for increasing human exposure to the CWD agent. The foodborne transmission of bovine spongiform encephalopathy to humans indicates that the species barrier may not completely protect humans from animal prion diseases. Conversion of human prion protein by CWD-associated prions has been demonstrated in an in vitro cell-free experiment, but limited investigations have not identified strong evidence for CWD transmission to humans. More epidemiologic and laboratory studies are needed to monitor the possibility of such transmissions.

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Volume 12, Number 10-October 2006 Research

Human Prion Disease and Relative Risk Associated with Chronic Wasting Disease

Samantha MaWhinney,* W. John Pape,? Jeri E. Forster,* C. Alan Anderson,?§ Patrick Bosque,?¶ and Michael W. Miller# *University of Colorado at Denver and Health Sciences Center, Denver, Colorado, USA; ?Colorado Department of Public Health and Environment, Denver, Colorado, USA; ?University of Colorado School of Medicine, Denver, Colorado, USA; §Denver Veteran's Affairs Medical Center, Denver, Colorado, USA; ¶Denver Health Medical Center, Denver, Colorado, USA; and #Colorado Division of Wildlife, Fort Collins, Colorado,

USA Suggested citation for this article

The transmission of the prion disease bovine spongiform encephalopathy (BSE) to humans raises concern about chronic wasting disease (CWD), a prion disease of deer and elk. In 7 Colorado counties with high CWD prevalence, 75% of state hunting licenses are issued locally, which suggests that residents consume most regionally harvested game. We used Colorado death certificate data from 1979 through 2001 to evaluate rates of death from the human prion disease Creutzfeldt-Jakob disease (CJD). The relative risk (RR) of CJD for CWD-endemic county residents was not significantly increased (RR 0.81, 95% confidence interval [CI] 0.40-1.63), and the rate of CJD did not increase over time (5-year RR 0.92, 95% CI 0.73-1.16). In Colorado, human prion disease resulting from CWD exposure is rare or nonexistent. However, given uncertainties about the incubation period, exposure, and clinical presentation, the possibility that the CWD agent might cause human disease cannot be eliminated.

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Dr. Spraker: You also hear that CWD is always fatal. I don’t believe that. I see too many cases of animals that are big and fat and healthy-looking, killed by a hunter, and they have so much prion in the brain it's unbelievable. Even in later cases, there are a lot of them that do not show clinical signs. The degree of spongiform degeneration is not nearly as high in some animals as in others. We're slowing pushing in that direction to see what the difference is.

Dr. Bartz: One of the hallmarks of inter-species transmission, at least in rodents, is that the spongiform degeneration is way out of proportion in the first transmission to what you see in subsequent transmission. If you just look at brain sections, you can always pick out the animal that's the first passage because the spongiform lesions are so much more intense.

Dr. Spraker: And the amount of accumulated prion is less, right?

Dr. Bartz: It can be less. That hasn't been looked at thoroughly enough.

Dr. Spraker: We see animals that have had this disease for three years and we see hardly any spongiform change, but yet you see lots of accumulation of PRP. But when they tell you that every animal that gets CWD dies, how do you prove that?

Dr. Thornsberry: If that animal doesn’t die and he's a plus three or plus four, he's shedding prions all over creation. So you have an infectious disease with an infectious agent in the environment.

Dr. Spraker: The state vets don't like to hear that. No one can prove it. But just with casual observation over the years, I don't believe that statement anymore. It might take a lifetime to prove it, but I think that not even thinking about it is more dangerous than trying it and not being able to prove it. That might help to explain all these mysterious crop-ups of CWD. If it does come from sheep, that would help, but it's not a simple thing. There are two or three cogs that have to go and prions are just one of them. You can make it work with one in the lab, but natural, it's going to take two or three.

Dr. Keller: Do you remember what the requirements are in Canada after finding a positive case of CWD on a cervid premises? I believe they do not let ruminants back into the same facility for three years or five years?

Dr. Spraker: It varies, but I think it’s around five. South Dakota is five.

Dr. Detwiler: They're changing again. They just recently discussed it.


Dr. Linda Detwiler: I'm going to take a different approach. I'm going to talk about scientific findings and how they're pertinent and why they're important to regulatory policy. We know there have been about 150 deaths from variant CJD from 1986. These are very tragic indeed, however, there are a lot more deaths from the flu and other diseases, yet this is what's made headlines and created a panic.

The objective is to review the research significant to regulatory issues and what's know and—equally important—what's not known. We'll look at the BSE case in Canada and what happened there and what may have happened in their feed cycle. We'll look at implications for the US and possible next steps.

It's important for us to know the similarities, and equally important to know the differences. The differences between species for control purposes, eradication, and prevention are so critical. If you don't know the differences in regards to transmission, pathogenesis, etc., you won't be able to control the diseases appropriately. For example you cannot control Scrapie like you do BSE with a feed ban.

My mantra is that you have to remember these long incubation diseases with limits to the pre-clinical. You have to be thinking. If you knew the disease was going to be here tomorrow, what should you have done yesterday? If you wait until the first time you find the disease, you are years too late. You might be one incubation cycle too late or multiple incubation cycles too late. The population you're concerned with, be it cows or sheep or elk or humans, it's already been infected and you're just going to live out the clinical manifestation of the disease.

Prevention is best, but if you know it’s been introduced, what can you do to limit the transmission? Europe has had to play it out.

The UK in 1988 put the ruminant-to-ruminant feed ban on, but they did not ban the total use. It's banned only for ruminants, so they had too much to use. It's not prohibited to go other places, so the meat and bone meal is sold to the continent. It dumps into France and starts to move throughout Europe. Add another five years incubation period, plus surveillance, and you see the manifestation of clinical detection in the Benelux countries.

Europe then started to restrict the use of meat and bone meal, and sale of it went on to other countries.

There are a lot of countries that probably have received product, but are not doing surveillance. This is something the US needs to watch out for. We don't classify countries like we do for other diseases, like foot and mouth. For BSE, we'll stop trade if a country is not okay, which is just the opposite from the policy for foot and mouth. This is something the US needs to change. We need to evaluate the countries of the world. Canada has done this and Canada will trade only if the BSE risk is at an acceptable level.

We can't forget other animal species are susceptible, such as cats. Domestic cats and large zoo cats are susceptible to the BSE agent, as well as TSEs of exotic ruminants. If exposed to the BSE agent, bison are susceptible.

Why is the distribution of infectivity important for us? There are several reasons from a regulatory standpoint. If you know where the infectivity is, it helps you eliminate high risk tissue, especially ones that might be a zoonotic risk. That is, What tissues might be more infectious to humans if it’s a zoonotic disease or out of the rations of other animlas if they’re susceptible. Also, it provides direction as to what tissues you might target for diagnostic purposes.

In natural cases of BSE, infectivity was in retina, brain and the spinal cord.

In the experimental challenges, calves were fed 100 grams of BSE-infected brain tissue. At certain intervals, some were sacrificed. Forty-some tissues from these calves were put into mice to be bio-assayed. The British were criticized, saying the mouse bio-assay is not as sensitive because of the species barrier, and that you should go back and repeat this in cattle—at least for the most important tissues. This study in cattle had actually generated some additional data { that is additional tissues where infectivity has been found}. The trigeminal ganglia, the dorsal ganglia, the distal ileum and the bone marrow were all from the original mouse pathogenesis study. Recently, tonsil has been found to have infectivity by a calf bio-assay.

Pre-clinically, the distal ileum was six months post-inoculation, and the tonsil was about 10 months post-inoculation. To date, cattle muscle samples have been put into mice and also back into cattle, and no infectivity has been found. Scrapie infectivity has been identified in brain, spinal cord, tonsil, the peripheral lymph nodes, nasal mucosa, placenta, liver, and the length of the intestine from the esophagus to the rectum. Nora Hunter has published work where both whole blood and buffy coat were taken from sheep and inoculated back into sheep from New Zealand, and those sheep did come down with TSE. Dr. Spraker: How did they demonstrate nasal mucosa?

Dr. Detwiler: Bill Hadwell collected nasal mucosa from Suffolk sheep and inoculated it into mice.

In baby ruminants, the cells of the distal ileum are a different cell type up until about nine months of age. The cell type is such that they allow the passage of large molecules to transported across the intestine. By about nine months, that function wanes. It's probably for colostral purposes, for colostral antibodies to transfer over. But some have asked if that's why there's an ease of transmission across the gut at a younger age. Horrigan's work at Mission, Texas, showed that after nine months, it appeared to be more difficult to transmit Scrapie. It may be there's a correlation with the change of cell types.

This is a chart I made for the OIE, the Office of International Epizootics to look at secretions and excretions in sheep and goats where, to date, no infectivity had been found in feces, urine, saliva, colostrum, milk and semen. Intra-cranial inoculation into mice resulted in no infectivity. But I want to point out that I don't think we should stop looking. Even with the blood. If you had asked someone prior to 2000 if infectivity was ever found in sheep's blood, he would have said "no," because work done to that time had not shown infectivity in sheep blood. But that work was all blood intra-cranially into mice. How much blood, feces and saliva can you put intra-cranially into a mouse?

Dr. Bartz: With BSE into mice, they estimated a 104 difference in sensitivity between the cow and the mouse.

Dr. Detwiler: How about nasal discharge? Is that a possibility for shed of the agent? We have to keep asking these questions, even for cattle. If it's in the lymphoid tissue of the distal ileum, the tonsil, or the lymphoid tissue of the third eyelid, would it not make sense that, at least at some low level, there might be some lymphoreticular distribution similar to the other animals with TSE. I think that's a valid question to ask, and the calf pathogenesis studies are not finished. I think we have to be careful definitively in saying it's limited to only two three peripheral tissues.

Dr. Detwiler:

Dr. Prusiner is examing muscle from cattle with BSE, and looking for presence of PRP and probably infectivity.

Dr. Thornsberry: He's very concerned about muscle tissue.

Dr. Bartz: There's one comment I'd like to make on the muscle infectivity studies. We need to remember that a lot of these are taking a biopsy. If you take a biopsy of muscle, what's in that? It's obviously muscle cells, but it's also nervous tissue and LRS tissue. It's in a muscle homogenate, which is consumed, but the question remains what cell type in that homogenate is the agent really in?

Dr. Detwiler: I asked that of Dr. Prusiner. How did they ascertain that it was muscle cells versus nerve tissue, etc. He said they were very careful in how they took the biopsy.

Dr. Thornsberry: Doesn't every muscle biopsy have some neural tissue in it?

Dr. Detwiler: There's some innervation going to those muscle groups.



Infectivity in skeletal muscle of BASE-infected cattle

Silvia Suardi1, Chiara Vimercati1, Fabio Moda1, Ruggerone Margherita1, Ilaria Campagnani1, Guerino Lombardi2, Daniela Gelmetti2, Martin H. Groschup3, Anne Buschmann3, Cristina Casalone4, Maria Caramelli4, Salvatore Monaco5, Gianluigi Zanusso5, Fabrizio Tagliavini1 1Carlo Besta” Neurological Institute,Italy; 2IZS Brescia, Italy; 33FLI Insel Riems, D, Germany; 4CEA-IZS Torino, Italy; 5University of Verona, Italy

Background: BASE is an atypical form of bovine spongiform encephalopathy caused by a prion strain distinct from that of BSE. Upon experimental transmission to cattle, BASE induces a previously unrecognized disease phenotype marked by mental dullness and progressive atrophy of hind limb musculature. Whether affected muscles contain infectivity is unknown. This is a critical issue since the BASE strain is readily transmissible to a variety of hosts including primates, suggesting that humans may be susceptible.

Objectives: To investigate the distribution of infectivity in peripheral tissues of cattle experimentally infected with BASE.

Methods: Groups of Tg mice expressing bovine PrP (Tgbov XV, n= 7-15/group) were inoculated both i.c. and i.p. with 10% homogenates of a variety of tissues including brain, spleen, cervical lymph node, kidney and skeletal muscle (m. longissimus dorsi) from cattle intracerebrally infected with BASE. No PrPres was detectable in the peripheral tissues used for inoculation either by immunohistochemistry or Western blot.

Results: Mice inoculated with BASE-brain homogenates showed clinical signs of disease with incubation and survival times of 175±15 and 207±12 days. Five out of seven mice challenged with skeletal muscle developed a similar neurological disorder, with incubation and survival times of 380±11 and 410±12 days. At present (700 days after inoculation) mice challenged with the other peripheral tissues are still healthy. The neuropathological phenotype and PrPres type of the affected mice inoculated either with brain or muscle were indistinguishable and matched those of Tgbov XV mice infected with natural BASE.

Discussion: Our data indicate that the skeletal muscle of cattle experimentally infected with BASE contains significant amount of infectivity, at variance with BSE-affected cattle, raising the issue of intraspecies transmission and the potential risk for humans. Experiments are in progress to assess the presence of infectivity in skeletal muscles of natural BASE. Selected by the scientific committee from the submitted abstracts

Thursday, June 24, 2010

Accumulation of L-type Bovine Prions in Peripheral Nerve Tissues

Volume 16, Number 7–July 2010

Muscle tissue has recently been detected with PrPSc in the peripheral nerves (sciatic nerve, tibial nerve, vagus nerve) of the 11th BSE cow in Japan (Yoshifumi Iwamaru et al). also recently, Aguzzi et al Letter to the Editor Vet Pathol 42:107-108 (2005), Prusiner et al CDI test is another example of detection of the TSE agent in muscle in sCJD, Herbert Budka et al CJD and inclusion body myositis:

Abundant Disease-Associated Prion Protein in Muscle, and older studies from Watson Meldrum et al Scrapie agent in muscle - Pattison I A (1990), references as follow ;

PrPSc distribution of a natural case of bovine spongiform encephalopathy

Yoshifumi Iwamaru, Yuka Okubo, Tamako Ikeda, Hiroko Hayashi, Mori- kazu Imamura, Takashi Yokoyama and Morikazu Shinagawa Priori Disease Research Center, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba 305-0856 Japan

Abstract Bovine spongiform encephalopathy (BSE) is a disease of cattle that causes progressive neurodegeneration of the central nervous system. Infectivity of BSE agent is accompanied with an abnormal isoform of prion protein (PrPSc). The specified risk materials (SRM) are tissues potentially carrying BSE infectivity. The following tissues are designated as SRM in Japan: the skull including the brain and eyes but excluding the glossa and the masse- ter muscle, the vertebral column excluding the vertebrae of the tail, spinal cord, distal illeum. For a risk management step, the use of SRM in both animal feed or human food has been prohibited. However, detailed PrPSc distribution remains obscure in BSE cattle and it has caused con- troversies about definitions of SRM. Therefore we have examined PrPSc distribution in a BSE cattle by Western blotting to reassess definitions of SRM.

The 11th BSE case in Japan was detected in fallen stock surveillance. The carcass was stocked in the refrigerator. For the detection of PrPSc, 200 mg of tissue samples were homogenized. Following collagenase treatment, samples were digested with proteinase K. After digestion, PrPSc was precipitated by sodium phosphotungstate (PTA). The pellets were subjected to Western blotting using the standard procedure. Anti-prion protein monoclonal antibody (mAb) T2 conjugated horseradish peroxidase was used for the detection of PrPSc. PrPSc was detected in brain, spinal cord, dorsal root ganglia, trigeminal ganglia, sublingual ganglion, retina. In addition, PrPSc was also detected in the peripheral nerves (sciatic nerve, tibial nerve, vagus nerve). Our results suggest that the currently accepted definitions of SRM in BSE cattle may need to be reexamined. ...


T. Kitamoto (Ed.) PRIONS Food and Drug Safety


ALSO from the International Symposium of Prion Diseases held in Sendai, October 31, to November 2, 2004; Bovine spongiform encephalopathy (BSE) in Japan


"Furthermore, current studies into transmission of cases of BSE that are atypical or that develop in young cattle are expected to amplify the BSE prion"

NO. Date conf. Farm Birth place and Date Age at diagnosis

8. 2003.10.6. Fukushima Tochigi 2001.10.13. 23

9. 2003.11.4. Hiroshima Hyogo 2002.1.13. 21

Test results

# 8b, 9c cows Elisa Positive, WB Positive, IHC negative, histopathology negative

b = atypical BSE case

c = case of BSE in a young animal

b,c, No PrPSc on IHC, and no spongiform change on histology

International Symposium of Prion Diseases held in Sendai, October 31, to November 2, 2004.

The hardback book title is 'PRIONS' Food and Drug Safety

T. Kitamoto (Ed.) Tetsuyuki Kitamoto Professor and Chairman Department of Prion Research Tohoku University School of Medicine 2-1 SeiryoAoba-ku, Sendai 980-8575, JAPAN TEL +81-22-717-8147 FAX +81-22-717-8148 e-mail; Symposium Secretariat Kyomi Sasaki TEL +81-22-717-8233 FAX +81-22-717-7656 e-mail:


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(American Journal of Pathology. 2006;168:927-935.) © 2006 American Society for Investigative Pathology

Detection and Localization of PrPSc in the Skeletal Muscle of Patients with Variant, Iatrogenic, and Sporadic Forms of Creutzfeldt-Jakob Disease

Alexander H. Peden, Diane L. Ritchie, Mark W. Head and James W. Ironside From the National Creutzfeldt-Jakob Disease Surveillance Unit and Division of Pathology, School of Molecular and Clinical Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom


Materials and Methods Results Discussion References

Variant Creutzfeldt-Jakob disease (vCJD) differs from other human prion diseases in that the pathogenic prion protein PrPSc can be detected to a greater extent at extraneuronal sites throughout the body, principally within lymphoid tissues. However, a recent study using a high-sensitivity Western blotting technique revealed low levels of PrPSc in skeletal muscle from a quarter of Swiss patients with sporadic CJD (sCJD). This posed the question of whether PrPSc in muscle could also be detected in vCJD, sCJD, and iatrogenic (iCJD) patients from other populations. Therefore, we have used the same high-sensitivity Western blotting technique, in combination with paraffin-embedded tissue blotting, to screen for PrPSc in muscle tissue specimens taken at autopsy from 49 CJD patients in the United Kingdom. These techniques identified muscle PrPSc in 8 of 17 vCJD, 7 of 26 sCJD, and 2 of 5 iCJD patients. Paraffin-embedded tissue blotting analysis showed PrPSc in skeletal muscle in localized anatomical structures that had the morphological and immunohistochemical characteristics of nerve fibers. The detection of PrPSc in muscle tissue from all forms of CJD indicates the possible presence of infectivity in these tissues, suggesting important implications for assessing the potential risk of iatrogenic spread via contaminated surgical instruments. Public Health Implications There is a strong correlation between the presence of PrPSc and infectivity in prion diseases. Hence these studies would suggest that prion infectivity is indeed present in the skeletal muscle tissue from all forms of CJD, both acquired and sporadic, albeit at levels two orders of magnitude lower than those found in the CNS. The presence of PrPSc in skeletal muscle suggests that the potential risk of iatrogenic spread may be a cause for concern for a range of surgical procedures, although further investigation is required to allow a full risk assessment.


To date the OIE/WAHO assumes that the human and animal health standards set out in the BSE chapter for classical BSE (C-Type) applies to all forms of BSE which include the H-type and L-type atypical forms. This assumption is scientifically not completely justified and accumulating evidence suggests that this may in fact not be the case. Molecular characterization and the spatial distribution pattern of histopathologic lesions and immunohistochemistry (IHC) signals are used to identify and characterize atypical BSE. Both the L-type and H-type atypical cases display significant differences in the conformation and spatial accumulation of the disease associated prion protein (PrPSc) in brains of afflicted cattle. Transmission studies in bovine transgenic and wild type mouse models support that the atypical BSE types might be unique strains because they have different incubation times and lesion profiles when compared to C-type BSE. When L-type BSE was inoculated into ovine transgenic mice and Syrian hamster the resulting molecular fingerprint had changed, either in the first or a subsequent passage, from L-type into C-type BSE.

In addition, non-human primates are specifically susceptible for atypical BSE as demonstrated by an approximately 50% shortened incubation time for L-type BSE as compared to C-type. Considering the current scientific information available, it cannot be assumed that these different BSE types pose the same human health risks as C-type BSE or that these risks are mitigated by the same protective measures.

14th ICID International Scientific Exchange Brochure -

Final Abstract Number: ISE.114 Session:

International Scientific Exchange

Transmissible Spongiform encephalopathy (TSE) animal and human TSE in North America update October 2009

T. Singeltary Bacliff, TX, USA

Background: An update on atypical BSE and other TSE in North America. Please remember, the typical U.K. c-BSE, the atypical l-BSE (BASE), and h-BSE have all been documented in North America, along with the typical scrapie's, and atypical Nor-98 Scrapie, and to date, 2 different strains of CWD, and also TME. All these TSE in different species have been rendered and fed to food producing animals for humans and animals in North America (TSE in cats and dogs ?), and that the trading of these TSEs via animals and products via the USA and Canada has been immense over the years, decades.

Methods: 12 years independent research of available data

Results: I propose that the current diagnostic criteria for human TSEs only enhances and helps the spreading of human TSE from the continued belief of the UKBSEnvCJD only theory in 2009. With all the science to date refuting it, to continue to validate this old myth, will only spread this TSE agent through a multitude of potential routes and sources i.e. consumption, medical i.e., surgical, blood, dental, endoscopy, optical, nutritional supplements, cosmetics etc.

Conclusion: I would like to submit a review of past CJD surveillance in the USA, and the urgent need to make all human TSE in the USA a reportable disease, in every state, of every age group, and to make this mandatory immediately without further delay. The ramifications of not doing so will only allow this agent to spread further in the medical, dental, surgical arena's. Restricting the reporting of CJD and or any human TSE is NOT scientific. Iatrogenic CJD knows NO age group, TSE knows no boundaries. I propose as with Aguzzi, Asante, Collinge, Caughey, Deslys, Dormont, Gibbs, Gajdusek, Ironside, Manuelidis, Marsh, et al and many more, that the world of TSE Transmissible Spongiform Encephalopathy is far from an exact science, but there is enough proven science to date that this myth should be put to rest once and for all, and that we move forward with a new classification for human and animal TSE that would properly identify the infected species, the source species, and then the route.

see page 114 ;


Dr. Detwiler: Parenterally, BSE does go into pigs. It was through three routes: intra-cranial, IV and IP with incubation times of 69 to 150 weeks. Seven out of 10 came down with BSE. Orally, it did not go after 84 months. It's important to note that infectivity was not confined only to the CNS, but also in stomach, jejunum, distal ileum and pancreas.

With chickens, both parenterally and orally, they did not find evidence of disease. They tried to sub-passage the chickens by taking brain from animals that had been exposed, to see if it adapted. I think you may have to do this multiple times. What the research in the UK did do was look at high-risk tissues from pigs and chickens that had been exposed to BSE, and put them into susceptible mice. Again, we have to be careful to say there's no residual infectivity at all. If continually fed to a species over time , there may be some kind of passage or adaptation over time. That's why, in other countries, they take out high-risk tissues and don't allow them to be fed at all. In Europe, they've gone to the extreme of taking out all animal tissue being fed to food-producing animals, to break this cycle.

Lateral Transmission

Scrapie and CWD spread animal to animal. In both embryo and semen studies, infectivity for transmission of BSE was not detected.

Two cases of disease with fairly significant numbers have been caused by making vaccines from tissues from animals incubating the disease. Just recently, a Mycoplasma aglacia vaccine that was given to sheep and goats in Italy caused infection in 600 to 700 premises.



Scrapie Louping-ill vaccine



Contaminated feed appears to be the primary if not sole source of infectivity. Animals that are incubating the disease get slaughtered, rendered, and fed back to other cattle, and they get sick in an average of three to six years.

This is significant to me when we talk about the British attack rate studies. In this experiment, infected brain was given orally. One gram killed seven of 10, so the British knew that had to go down to lower doses. They've now looked at a tenth of a gram and a hundredth and a thousandth of a gram. This is still underway, but at about 60 months, a tenth of gram has killed three of 15 animals affected with BSE, and a hundredth of a gram has killed one of 15 thus far at a 50-plus-month incubation. It doesn’t take too much brain material. The British message is to not underestimate the possibility of cross-contamination in the feed cycle. In the United States we allow mills and plant to use the same equipment when processing ruminant and non-ruminant material. Although a system of cleaning is required by the FDA, the science questions how effective the flush methodologies could really be. The same trucks may haul ruminant and non-ruminant feeds. Those are potentials for cross-contamination.

Dr. Keller: What about risk from feather meal/poultry litter?

Dr. Detwiler: Feather meal can pick up infectivity from other feeds.

Dr. Keller: Whenever you feed a ruminant product to chickens and then the feathers/litter are collected, they're collecting the ruminant material directly in the spillage.

Dr. Detwiler: Hold on to that thought and I'll address it later.

A big unknown for the whole world but important to answer involves sheep. BSE goes into sheep orally and maintains BSE characteristics. In research, it looks like Scrapie clinically and histologically. To date, the only valid way to differentiate BSE and Scrapie in sheep is a mouse bio-assay. Would it spread? If it does go naturally into sheep, would it spread like Scrapie through some kind of contagious nature?

So far, the distribution of infectivity is looking identical to Scrapie. The significance of this is that the worst case scenario would be BSE in sheep naturally. You would have a potentially zoonotic disease that could spread from sheep to sheep and could not be differentiated from a common endemic disease, would have a widespread tissue distribution, peripheral nerve, blood, so no tissue of the sheep would really be safe. What would countries do if they found this? That's about 40 million sheep.

Dr. Bartz: Do you know if anyone is taking material from the BSE-infected sheep and inoculating non-human primates, to see if it looks like variant CJD?

Dr. Detwiler: It seems a good idea, but I'm not aware of it.

Another important thing to get across to the public is that the negatives do not guarantee absence of infectivity. The animal could be early in the disease and the incubation period. Even sample collection is so important. If you're not collecting the right area of the brain in sheep, or if collecting lymphoreticular tissue, and you don't get a good biopsy, you could miss the area with the PRP in it and come up with a negative test.

There's a new, unusual form of Scrapie that's been detected in Norway. We have to be careful that we don’t get so set in the way we do things that we forget to look for different emerging variations of disease. We've gotten away from collecting the whole brain in our systems. We're using the brain stem and we're looking in only one area. In Norway, they were doing a project and looking at cases of Scrapie, and they found this where they did not find lesions or PRP in the area of the obex. They found it in the cerebellum and the cerebrum. It's a good lesson for us. Ames had to go back and change the procedure for looking at Scrapie samples. In the USDA, we had routinely looked at all the sections of the brain, and then we got away from it. They've recently gone back.

Dr. Keller: Tissues are routinely tested, based on which tissue provides an ‘official’ test result as recognized by APHIS Dr. Detwiler: That's on the slaughter. But on the clinical cases, aren’t they still asking for the brain? But even on the slaughter, they're looking only at the brainstem. We may be missing certain things if we confine ourselves to one area.



Spread of BSE prions in cynomolgus monkeys (Macaca fascicularis) after oral transmission

Edgar Holznagel1, Walter Schulz-Schaeffer2, Barbara Yutzy1, Gerhard Hunsmann3, Johannes Loewer1 1Paul-Ehrlich-Institut, Federal Institute for Sera and Vaccines, Germany; 2Department of Neuropathology, Georg-August University, Göttingen, Germany, 3Department of Virology and Immunology, German Primate Centre, Göttingen, Germany

Background: BSE-infected cynomolgus monkeys represent a relevant animal model to study the pathogenesis of variant Creutzfeldt-Jacob disease (vCJD).

Objectives: To study the spread of BSE prions during the asymptomatic phase of infection in a simian animal model.

Methods: Orally BSE-dosed macaques (n=10) were sacrificed at defined time points during the incubation period and 7 orally BSE-dosed macaques were sacrificed after the onset of clinical signs. Neuronal and non-neuronal tissues were tested for the presence of proteinase-K-resistant prion protein (PrPres) by western immunoblot and by paraffin-embedded tissue (PET) blot technique.

Results: In clinically diseased macaques (5 years p.i. + 6 mo.), PrPres deposits were widely spread in neuronal tissues (including the peripheral sympathetic and parasympathetic nervous system) and in lymphoid tissues including tonsils. In asymptomatic disease carriers, PrPres deposits could be detected in intestinal lymph nodes as early as 1 year p.i., but CNS tissues were negative until 3 – 4 years p.i. Lumbal/sacral segments of the spinal cord and medulla oblongata were PrPres positive as early as 4.1 years p.i., whereas sympathetic trunk and all thoracic/cervical segments of the spinal cord were still negative for PrPres. However, tonsil samples were negative in all asymptomatic cases.

Discussion: There is evidence for an early spread of BSE to the CNS via autonomic fibres of the splanchnic and vagus nerves indicating that trans-synaptical spread may be a time-limiting factor for neuroinvasion. Tonsils were predominantly negative during the main part of the incubation period indicating that epidemiological vCJD screening results based on the detection of PrPres in tonsil biopsies may mostly tend to underestimate the prevalence of vCJD among humans.


Transmission of atypical BSE in humanized mouse models

Liuting Qing1, Wenquan Zou1, Cristina Casalone2, Martin Groschup3, Miroslaw Polak4, Maria Caramelli2, Pierluigi Gambetti1, Juergen Richt5, Qingzhong Kong1 1Case Western Reserve University, USA; 2Instituto Zooprofilattico Sperimentale, Italy; 3Friedrich-Loeffler-Institut, Germany; 4National Veterinary Research Institute, Poland; 5Kansas State University (Previously at USDA National Animal Disease Center), USA

Background: Classical BSE is a world-wide prion disease in cattle, and the classical BSE strain (BSE-C) has led to over 200 cases of clinical human infection (variant CJD). Atypical BSE cases have been discovered in three continents since 2004; they include the L-type (also named BASE), the H-type, and the first reported case of naturally occurring BSE with mutated bovine PRNP (termed BSE-M). The public health risks posed by atypical BSE were largely undefined.

Objectives: To investigate these atypical BSE types in terms of their transmissibility and phenotypes in humanized mice. Methods: Transgenic mice expressing human PrP were inoculated with several classical (C-type) and atypical (L-, H-, or Mtype) BSE isolates, and the transmission rate, incubation time, characteristics and distribution of PrPSc, symptoms, and histopathology were or will be examined and compared.

Results: Sixty percent of BASE-inoculated humanized mice became infected with minimal spongiosis and an average incubation time of 20-22 months, whereas only one of the C-type BSE-inoculated mice developed prion disease after more than 2 years. Protease-resistant PrPSc in BASE-infected humanized Tg mouse brains was biochemically different from bovine BASE or sCJD. PrPSc was also detected in the spleen of 22% of BASE-infected humanized mice, but not in those infected with sCJD. Secondary transmission of BASE in the humanized mice led to a small reduction in incubation time. The atypical BSE-H strain is also transmissible with distinct phenotypes in the humanized mice, but no BSE-M transmission has been observed so far.

Discussion: Our results demonstrate that BASE is more virulent than classical BSE, has a lymphotropic phenotype, and displays a modest transmission barrier in our humanized mice.

BSE-H is also transmissible in our humanized Tg mice. The possibility of more than two atypical BSE strains will be discussed.

Supported by NINDS NS052319, NIA AG14359, and NIH AI 77774.


Transmission of BSE to Cynomolgus Macaque, a Non-human Primate; Development of Clinical Symptoms and Tissue Distribution of PrPSC

Yamakawa, Y1; Ono, F2; Tase, N3; Terao, K3; Tannno, J3; Wada, N4; Tobiume, M5; Sato, Y5; Okemoto-Nakamura, Y1; Hagiwara, K1; Sata, T5 1National Institure of Infectious diseases, Cell biology and Biochemistry, Japan; 2Corporation for Production and Research Laboratory Primates., Japan; 3National Institure of Biomedical Innovation, Tsukuba Primate Reserch Center, Japan; 4Yamauchi Univ., Veterinary Medicine, Japan; 5National Institure of Infectious diseases, Pathology, Japan

Two of three cynomolgus monkeys developed abnormal neuronal behavioral signs at 30-(#7) and 28-(#10) months after intracerebral inoculation of 200ul of 10% brain homogenates of BSE affected cattle (BSE/JP6). Around 30 months post inoculation (mpi), they developed sporadic anorexia and hyperekplexia with squeal against environmental stimulations such as light and sound. Tremor, myoclonic jerk and paralysis became conspicuous during 32 to 33-mpi, and symptoms become worsened according to the disease progression. Finally, one monkey (#7) fell into total paralysis at 36-mpi. This monkey was sacrificed at 10 days after intensive veterinary care including infusion and per oral supply of liquid food. The other monkey (#10) had to grasp the cage bars to keep an upright posture caused by the sever ataxia. This monkey was sacrificed at 35-mpi. EEG of both monkeys showed diffuse slowing. PSD characteristic for sporadic CJD was not observed in both monkeys. The result of forearm movement test showed the hypofunction that was observed at onset of clinical symptoms. Their cognitive function determined by finger maze test was maintained at the early stage of sideration. However, it was rapidly impaired followed by the disease progression. Their autopsied tissues were immunochemically investigated for the tissue distribution of PrPSc. Severe spongiform change in the brain together with heavy accumulation of PrPSc having the type 2B/4 glycoform profile confirmed successful transmission of BSE to Cynomolgus macaques. Granular and linear deposition of PrPSC was detected by IHC in the CNS of both monkeys. At cerebral cortex, PrPSC was prominently accumulated in the large plaques. Sparse accumulation of PrPSc was detected in several peripheral nerves of #7 but not in #10 monkey, upon the WB analysis. Neither #7 nor #10 monkey accumulated detectable amounts of PrPSc in their lymphatic organs such as tonsil, spleen, adrenal grands and thymus although PrPSc was barely detected in the submandibular lymph node of #7 monkey. Such confined tissue distribution of PrPSc after intracerebral infection with BSE agent is not compatible to that reported on the Cynomolgus macaques infected with BSE by oral or intra-venous (intra-peritoneal) routs, in which PrPSc was accumulated at not only CNS but also widely distributed lymphatic tissues.


Experimental BSE Infection of Non-human Primates: Efficacy of the Oral Route

Holznagel, E1; Yutzy, B1; Deslys, J-P2; Lasmézas, C2; Pocchiari, M3; Ingrosso, L3; Bierke, P4; Schulz-Schaeffer, W5; Motzkus, D6; Hunsmann, G6; Löwer, J1 1Paul-Ehrlich-Institut, Germany; 2Commissariat à l´Energie Atomique, France; 3Instituto Superiore di Sanità, Italy; 4Swedish Institute for Infectious Disease control, Sweden; 5Georg August University, Germany; 6German Primate Center, Germany

Background: In 2001, a study was initiated in primates to assess the risk for humans to contract BSE through contaminated food. For this purpose, BSE brain was titrated in cynomolgus monkeys.

Aims: The primary objective is the determination of the minimal infectious dose (MID50) for oral exposure to BSE in a simian model, and, by in doing this, to assess the risk for humans. Secondly, we aimed at examining the course of the disease to identify possible biomarkers.

Methods: Groups with six monkeys each were orally dosed with lowering amounts of BSE brain: 16g, 5g, 0.5g, 0.05g, and 0.005g. In a second titration study, animals were intracerebrally (i.c.) dosed (50, 5, 0.5, 0.05, and 0.005 mg).

Results: In an ongoing study, a considerable number of high-dosed macaques already developed simian vCJD upon oral or intracerebral exposure or are at the onset of the clinical phase. However, there are differences in the clinical course between orally and intracerebrally infected animals that may influence the detection of biomarkers.

Conclusions: Simian vCJD can be easily triggered in cynomolgus monkeys on the oral route using less than 5 g BSE brain homogenate. The difference in the incubation period between 5 g oral and 5 mg i.c. is only 1 year (5 years versus 4 years). However, there are rapid progressors among orally dosed monkeys that develop simian vCJD as fast as intracerebrally inoculated animals.

The work referenced was performed in partial fulfilment of the study “BSE in primates“ supported by the EU (QLK1-2002-01096).

Simian vCJD can be easily triggered in cynomolgus monkeys on the oral route using less than 5 g BSE brain homogenate.

WE know now, and we knew decades ago, that 5.5 grams of suspect feed in TEXAS was enough to kill 100 cows.

look at the table and you'll see that as little as 1 mg (or 0.001 gm) caused 7% (1 of 14) of the cows to come down with BSE;

Risk of oral infection with bovine spongiform encephalopathy agent in primates

Corinne Ida Lasmézas, Emmanuel Comoy, Stephen Hawkins, Christian Herzog, Franck Mouthon, Timm Konold, Frédéric Auvré, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Nicole Salès, Gerald Wells, Paul Brown, Jean-Philippe Deslys

Summary The uncertain extent of human exposure to bovine spongiform encephalopathy (BSE)--which can lead to variant Creutzfeldt-Jakob disease (vCJD)--is compounded by incomplete knowledge about the efficiency of oral infection and the magnitude of any bovine-to-human biological barrier to transmission. We therefore investigated oral transmission of BSE to non-human primates. We gave two macaques a 5 g oral dose of brain homogenate from a BSE-infected cow. One macaque developed vCJD-like neurological disease 60 months after exposure, whereas the other remained free of disease at 76 months. On the basis of these findings and data from other studies, we made a preliminary estimate of the food exposure risk for man, which provides additional assurance that existing public health measures can prevent transmission of BSE to man.


BSE bovine brain inoculum

100 g 10 g 5 g 1 g 100 mg 10 mg 1 mg 0·1 mg 0·01 mg

Primate (oral route)* 1/2 (50%)

Cattle (oral route)* 10/10 (100%) 7/9 (78%) 7/10 (70%) 3/15 (20%) 1/15 (7%) 1/15 (7%)

RIII mice (ic ip route)* 17/18 (94%) 15/17 (88%) 1/14 (7%)

PrPres biochemical detection

The comparison is made on the basis of calibration of the bovine inoculum used in our study with primates against a bovine brain inoculum with a similar PrPres concentration that was inoculated into mice and cattle.8 *Data are number of animals positive/number of animals surviving at the time of clinical onset of disease in the first positive animal (%). The accuracy of bioassays is generally judged to be about plus or minus 1 log. ic ip=intracerebral and intraperitoneal.

Table 1: Comparison of transmission rates in primates and cattle infected orally with similar BSE brain inocula

Published online January 27, 2005

It is clear that the designing scientists must also have shared Mr Bradleys surprise at the results because all the dose levels right down to 1 gram triggered infection.

it is clear that the designing scientists must have also shared Mr Bradleys surprise at the results because all the dose levels right down to 1 gram triggered infection.


Infectivity in skeletal muscle of BASE-infected cattle

Silvia Suardi1, Chiara Vimercati1, Fabio Moda1, Ruggerone Margherita1, Ilaria Campagnani1, Guerino Lombardi2, Daniela Gelmetti2, Martin H. Groschup3, Anne Buschmann3, Cristina Casalone4, Maria Caramelli4, Salvatore Monaco5, Gianluigi Zanusso5, Fabrizio Tagliavini1 1Carlo Besta” Neurological Institute,Italy; 2IZS Brescia, Italy; 33FLI Insel Riems, D, Germany; 4CEA-IZS Torino, Italy; 5University of Verona, Italy

Background: BASE is an atypical form of bovine spongiform encephalopathy caused by a prion strain distinct from that of BSE. Upon experimental transmission to cattle, BASE induces a previously unrecognized disease phenotype marked by mental dullness and progressive atrophy of hind limb musculature. Whether affected muscles contain infectivity is unknown. This is a critical issue since the BASE strain is readily transmissible to a variety of hosts including primates, suggesting that humans may be susceptible.

Objectives: To investigate the distribution of infectivity in peripheral tissues of cattle experimentally infected with BASE.

Methods: Groups of Tg mice expressing bovine PrP (Tgbov XV, n= 7-15/group) were inoculated both i.c. and i.p. with 10% homogenates of a variety of tissues including brain, spleen, cervical lymph node, kidney and skeletal muscle (m. longissimus dorsi) from cattle intracerebrally infected with BASE. No PrPres was detectable in the peripheral tissues used for inoculation either by immunohistochemistry or Western blot.

Results: Mice inoculated with BASE-brain homogenates showed clinical signs of disease with incubation and survival times of 175±15 and 207±12 days. Five out of seven mice challenged with skeletal muscle developed a similar neurological disorder, with incubation and survival times of 380±11 and 410±12 days. At present (700 days after inoculation) mice challenged with the other peripheral tissues are still healthy. The neuropathological phenotype and PrPres type of the affected mice inoculated either with brain or muscle were indistinguishable and matched those of Tgbov XV mice infected with natural BASE.

Discussion: Our data indicate that the skeletal muscle of cattle experimentally infected with BASE contains significant amount of infectivity, at variance with BSE-affected cattle, raising the issue of intraspecies transmission and the potential risk for humans. Experiments are in progress to assess the presence of infectivity in skeletal muscles of natural BASE.


Differences in the expression levels of selected genes in the brain tissue of cattle naturally infected with classical and atypical BSE.

Magdalena Larska1, Miroslaw P. Polak1, Jan F. Zmudzinski1, Juan M. Torres2 1National Veterinary Institute, Poland; 2CISA/INIA

Background: Recently cases of BSE in older cattle named BSE type L and type H were distinguished on the basis of atypical glycoprofiles of PrPres. The nature of those strains is still not fully understood but it is suspected that the atypical BSE cases are sporadic. Hitherto most BSE cases were studied in respect to the features of PrPSc. Here we propose gene expression profiling as a method to characterize and distinguish BSE strains.

Objectives: The aim of the study was to compare the activities of some factors which are known to play a role in TSE’s pathogenesis in order to distinguish the differences/similarities between all BSE types.

Methods: 10 % homogenate of brain stem tissue collected from obex region of medulla oblongata from 20 naturally infected BSE cows (8 assigned as classical BSE, other 8 and 4 infected with atypical BSE L type and H type respectively) was used in the study. As negative control animals we’ve used 8 animals in the age between 2.5 and 13 years. The genes were relatively quantified using SYBR Green real time RT-PCR. Raw data of Ct values was transformed into normalized relative quantities using Qbase Plus®.

Results and Discussion: In most of the tested genes significant differences in the expression levels between the brain stem of healthy cattle and animals infected with different BSE types were observed. In c-type BSE in comparison to healthy and atypical BSE the overexpression of the gene of bcl-2, caspase 3, 14-3-3 and tylosine kinase Fyn was significant. Simultaneously in atypical BSEs type-L and type-H the levels of prion protein, Bax and LPR gene was elevated in comparison to c-BSE. Additionally L-BSE was characterized by the overexpression of STI1 and SOD genes compared to the other of BSE types. The downregulation of the gene encoding NCAM1 was observed in all BSE types in comparison to healthy cows. Different gene expression profiles of bovine brains infected with classical and atypical BSE indicates possible different pathogenesis or source of the disease.

NOW, highly suspect banned mad cow feed in commerce USA a review 2010 ;



PRODUCT Bulk cattle feed made with recalled Darling’s 85% Blood Meal, Flash Dried, Recall # V-024-2007 CODE Cattle feed delivered between 01/12/2007 and 01/26/2007

RECALLING FIRM/MANUFACTURER Pfeiffer, Arno, Inc, Greenbush, WI. by conversation on February 5, 2007. Firm initiated recall is ongoing.

REASON Blood meal used to make cattle feed was recalled because it was cross-contaminated with prohibited bovine meat and bone meal that had been manufactured on common equipment and labeling did not bear cautionary BSE statement.





RECALLING FIRM/MANUFACTURER Rangen, Inc, Buhl, ID, by letters on February 13 and 14, 2007. Firm initiated recall is complete.

REASON Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement.




Sunday, January 17, 2010

BSE USA feed inspection violations 01/01/2009 to 01/17/2010 FDA BSE/Ruminant Feed Inspections Firms Inventory Report

Friday, January 15, 2010

New York Firm Recalls Beef Carcass That Contains Prohibited Materials (BSE)

Friday, September 4, 2009

FOIA REQUEST ON FEED RECALL PRODUCT 429,128 lbs. feed for ruminant animals may have been contaminated with prohibited material Recall # V-258-2009

Saturday, August 29, 2009

FOIA REQUEST FEED RECALL 2009 Product may have contained prohibited materials Bulk Whole Barley, Recall # V-256-2009


----- Original Message -----

From: "Terry S. Singeltary Sr."
Sent: Thursday, November 05, 2009 9:25 PM
Subject: [BSE-L] re-FOIA REQUEST ON FEED RECALL PRODUCT contaminated with prohibited material Recall # V-258-2009 and Recall # V-256-2009

Thursday, November 12, 2009

BSE FEED RECALL Misbranding of product by partial label removal to hide original source of materials 2009

CVM Annual Report Fiscal Year 2008: October 1, 2007-September 30, 2008


Monday, March 1, 2010


Terry S. Singeltary Sr. (Submitted question): Monday, April 5, 2010 Update on Feed Enforcement Activities to Limit the Spread of BSE April 5, 2010

Friday, April 23, 2010

Upcoming BSE Webinar on Thursday, April 22, 2010 a review

Owner and Corporation Plead Guilty to Defrauding Bovine Spongiform Encephalopathy (BSE) Surveillance Program

An Arizona meat processing company and its owner pled guilty in February 2007 to charges of theft of Government funds, mail fraud, and wire fraud. The owner and his company defrauded the BSE Surveillance Program when they falsified BSE Surveillance Data Collection Forms and then submitted payment requests to USDA for the services. In addition to the targeted sample population (those cattle that were more than 30 months old or had other risk factors for BSE), the owner submitted to USDA, or caused to be submitted, BSE obex (brain stem) samples from healthy USDA-inspected cattle. As a result, the owner fraudulently received approximately $390,000. Sentencing is scheduled for May 2007.



USDA: In 9,200 cases only one type of test could be used WASHINGTON (AP)--

The U.S. Department of Agriculture acknowledged Aug. 17 that its testing options for bovine spongiform encephalopathy were limited in 9,200 cases despite its effort to expand surveillance throughout the U.S. herd. In those cases, only one type of test was used--one that failed to detect the disease in an infected Texas cow. The department posted the information on its website because of an inquiry from The Associated Press. Conducted over the past 14 months, the tests have not been included in the department's running tally of BSE tests since last summer. That total reached 439,126 on Aug. 17. "There's no secret program," the department's chief veterinarian, John Clifford, said in an interview. "There has been no hiding, I can assure you of that." Officials intended to report the tests later in an annual report, Clifford said. These 9,200 cases were different because brain tissue samples were preserved with formalin, which makes them suitable for only one type of test--immunohistochemistry, or IHC. In the Texas case, officials had declared the cow free of disease in November after an IHC test came back negative. The department's inspector general ordered an additional kind of test, which confirmed the animal was infected. Veterinarians in remote locations have used the preservative on tissue to keep it from degrading on its way to the department's laboratory in Ames, Iowa. Officials this year asked veterinarians to stop using preservative and send fresh or chilled samples within 48 hours. The department recently investigated a possible case of BSE that turned up in a preserved sample. Further testing ruled out the disease two weeks ago. Scientists used two additional tests--rapid screening and Western blot--to help detect BSE in the country's second confirmed case, in a Texas cow in June. They used IHC and Western blot to confirm the first case, in a Washington state cow in December 2003. "The IHC test is still an excellent test," Clifford said. "These are not simple tests, either." Clifford pointed out that scientists reran the IHC several times and got conflicting results. That happened, too, with the Western blot test. Both tests are accepted by international animal health officials. Date: 8/25/05

"These 9,200 cases were different because brain tissue samples were preserved with formalin, which makes them suitable for only one type of test--immunohistochemistry, or IHC."



The U.S. Department of Agriculture was quick to assure the public earlier this week that the third case of mad cow disease did not pose a risk to them, but what federal officials have not acknowledged is that this latest case indicates the deadly disease has been circulating in U.S. herds for at least a decade. The second case, which was detected last year in a Texas cow and which USDA officials were reluctant to verify, was approximately 12 years old. These two cases (the latest was detected in an Alabama cow) present a picture of the disease having been here for 10 years or so, since it is thought that cows usually contract the disease from contaminated feed they consume as calves. The concern is that humans can contract a fatal, incurable, brain-wasting illness from consuming beef products contaminated with the mad cow pathogen. "The fact the Texas cow showed up fairly clearly implied the existence of other undetected cases," Dr. Paul Brown, former medical director of the National Institutes of Health's Laboratory for Central Nervous System Studies and an expert on mad cow-like diseases, told United Press International. "The question was, 'How many?' and we still can't answer that." Brown, who is preparing a scientific paper based on the latest two mad cow cases to estimate the maximum number of infected cows that occurred in the United States, said he has "absolutely no confidence in USDA tests before one year ago" because of the agency's reluctance to retest the Texas cow that initially tested positive. USDA officials finally retested the cow and confirmed it was infected seven months later, but only at the insistence of the agency's inspector general. "Everything they did on the Texas cow makes everything USDA did before 2005 suspect," Brown said. ...


CDC - Bovine Spongiform Encephalopathy and Variant Creutzfeldt ... Dr. Paul Brown is Senior Research Scientist in the Laboratory of Central Nervous System ... Address for correspondence: Paul Brown, Building 36, Room 4A-05, ...

Saturday, June 19, 2010



Why Do We Do Surveillance?

Is the disease present? You absolutely have to do surveillance to find out if the disease is present. It will also tell you if your prevention has been successful. If you have the disease, it will also give you indication that your controls are working. That's how Britain knew the feed ban had a big effect. They continued to monitor disease and they saw it peak and they saw it come down about five years after the implementation of the feed ban.

You also need surveillance for buyer confidence and for trade confidence with our international partners. BSE is found in older animals, over 24 months of age, high risk, those exposed to contaminated feed, neurologically ill cattle, any fallen stock and emergency slaughter. This is important to collect samples through active surveillance as owners will sometimes miss subtle signs.

In regards to inactivation, Paul Brown did some work and had to repeat it because people didn't believe it. He found that, at 600° degrees Celius, there was survival in the ash. However, there was none in air emission or the residue. At 1000° Celius, he found no survival.

Canada has actually had two cases of BSE. The first was an imported case in 1993—a UK import. This animal had a broken leg, but because it was a UK import, the owner called the government veterinary staff and they had it looked it. The Canadians had to do extensive tracings on all their UK imports because of this case.

The native case was, of course, in May 2003. This animal was six years old, an Angus type, presented for slaughter as down with signs of pneumonia. It was condemned at slaughter, so it did not go for human consumption. The head was taken for BSE surveillance, and the rest of the carcass went to rendering.

The 2003 animal was not related to any of the imports. Was it spontaneous, or was it a case of chronic wasting disease Epidemiologically, the animal was born in the spring of 1997 and was most likely infected at that time. Canada did import 182 head of cattle from the United Kingdom between 1981 and 1990, and there were 11 in the high-risk period, possibly incorporated into the animal feed chain. They also did a risk assessment, which showed they had a low risk of introduction.

They did trace-backs, and that helped to keep the public calm. There was no crisis. In fact, beef consumption went up in Canada. But they tried to find the herd of birth, which is really key in BSE. They narrowed it down to three herds, and all of these were put under quarantine. The cattle in those groups were pretty much depopulated.

When the positive animal was identified, CFIA did trace-backs, and that helped to keep the public calm. There was no crisis. In fact, beef consumption went up in Canada. But they tried to find the herd of birth, which is really key in BSE. They narrowed it down to three herds, and all of these were put under quarantine. The cattle in those groups were pretty much depopulated.

They do have a national ID system, but it had been in place for only two years. So they had to use other types of identification to trace back the animal. Subsequent to the depopulations, one herd was identified as the herd of birth.

One thing the OIE requires is that, for a country to resume trade in animals and animal products, they should depopulate progeny if it's a BSE-infected cow, along with birth cohorts. They had to depopulate over 100 head in these trace-forward herds.

The positive cow itself went to the slaughter plant and was condemned. The head went to the lab and the remaining carcass went to a renderer. From the renderer, the material could have gone to three farms. Two of these were poultry farms. The poultry farms also had cattle, and there was an admission that the cattle were fed the same material as the poultry. Again this is prohibited by the feed ban, but it happens on the farm. These three farms were depopulated in their eintirety.

This renderer did not have dedicated lines, so he made ruminant feed and non-ruminant, prohibited and non-prohibited. They used a barley flush. After the positive cow was processed, the barley flush went to one of these farms and could have been fed to cattle. That was another breakdown in the feed system. That's not supposed to happen, but it did.

It went to two pet-food plants. Material from the renderer at the time the animal might have been processed also went to a feed mill that had 1800 clients, but none of these was depopulated. There were violations. The message is that there are not a lot of resources for checking on-farm compliance with the feed ban. The rubber hits the road on the farm.

I already talked about the epidemiological investigation, the trace-forwards and the trace-backs. CFIA depopulated 2700 animals. They tested approximately 2000 of those. They also brought in an international review team made up of scientists from Switzerland, the US and New Zealand, who reviewed the epi investigation and found it to be thorough and complete. They made recommendations that Canada really had to get an SRM ban to take the high-risk materials out of the human good chain now. Canada has done that.

The committee told CFIA they needed to increase surveillance which examined high risk cattle in large numbers. The review team also said they had to find mechanisms to prevent this cross contamination in the animal food chain. Take out high-risk materials from the animal food chain period. Have dedicated mills, plants, etc.

The media was kind. There was no panic. However, rendering, slaughter and the producer level impacts are still significant. Initially, there was no place for the meat and bonemeal to go. The whole system started to back up. The renderers couldn’t sell it, so they filled their silos. The feed-mills filled their silos. They stopped slaughtering older cows because the system couldn’t take any more. The government started to help, and some things started to go to landfill.

Canada did put the SRM ban in place for public protection, but not yet for animals. CFIA is working on increasing surveillance, and they need to look at changes in the feed rule.

More Surveillance

North America needs Canada to increase surveillance. Right now, it's a black box. We need to know if it's a single, isolated case or not. With the way BSE works, that's not likely. Or are the ones that were exposed dead and long gone? If there were to be more cases, how many? And very important, if there are additional cases, how old are they? If they were all born prior to the feed ban, that lets us know the feed ban has been very effective. If not, we have had leaks.

This year (2003) for surveillance in Canada, they'll come to about the same level they had last year, about 3700 brains tests. They really need to kick this up. The recommendation by the international committee and even by their own government is up to the level of about 40,000.

Think about the whole task of on-farm compliance. You have hundreds of thousands of farms. How do you get 100% compliance? That's very difficult. You can’t be on all farms at all times. My philosophy is choke infectivity out high. If you take your infectivity out of the system at the highest point, what leaks through on the farm won’t matter. Take your high-risk material, your brains and spinal cords and your deads and downs, and get them completely out of the animal food chain. If people inadvertently feed the wrong material on the farm, it won't have the infectivity to keep the cycle going.

It doesn’t take much to introduce BSE into a country. Identification is extremely important. We don’t have a national ID system in place. We're moving in that direction, but how about if tomorrow we found a case of BSE here and we couldn't trace it back? We couldn’t stand up in front of the American public and say, "We don’t know where this animal came from." What would be the reaction?

Disposal itself can cause emergency situations and we need an infrastructure—not only for TSEs but for all animal diseases. The US and Canada both need some kind of infrastructure for proper animal disposal, for animal health and public health reasons.

Can it happen here in the US? Would we find it? To me, we could not have been more fortunate. We got a warning shot right in our neighbor's back yard. We now know that before May 20, we thought we had escaped the bullet of the agent coming to North America. May 20 showed us we were wrong. We know the agent entered North America in the indigenous population. We now have time to re-evaluate the risk, to look the lessons not only in Canada, but around the world. We can do it without having this crisis upon us.

We have import regulations, feed bans, etc. We've had import regulations in place since 1989 on live ruminants and ruminant products. This shouldn't be down-played. This is significant. Look at the way it spread through Europe. That was from imports of high-risk products.


Saturday, August 14, 2010

BSE Case Associated with Prion Protein Gene Mutation (g-h-BSEalabama) and VPSPr PRIONPATHY (see mad cow feed in COMMERCE IN ALABAMA...TSS)

g-h-BSE-alabama E211K mad cows USA how many would that be annually ???

if our ciphering is correct (?), that would be about 35 g-h-BSE-alabama E211K mad cows going into the food chain a year.

an incidence of less than 1 in 2000.

let's see, that's 500 such per million.

or 50,000 cows per 100 million (US herd size).

even at less than 1 in a million, with 35 million slaughtered, that's 35 infected cows going into the food chain each year.

hmmm, friendly fire there from ???

Wednesday, July 28, 2010

re-Freedom of Information Act Project Number 3625-32000-086-05, Study of Atypical BSE UPDATE July 28, 2010

Friday, August 27, 2010



Molecular characterization of BSE in Canada Jianmin

Yang1, Sandor Dudas2, Catherine Graham2, Markus Czub3, Tim McAllister1, Stefanie Czub1 1Agriculture and Agri-Food Canada Research Centre, Canada; 2National and OIE BSE Reference Laboratory, Canada; 3University of Calgary, Canada

Background: Three BSE types (classical and two atypical) have been identified on the basis of molecular characteristics of the misfolded protein associated with the disease. To date, each of these three types have been detected in Canadian cattle.

Objectives: This study was conducted to further characterize the 16 Canadian BSE cases based on the biochemical properties of there associated PrPres.

Methods: Immuno-reactivity, molecular weight, glycoform profiles and relative proteinase K sensitivity of the PrPres from each of the 16 confirmed Canadian BSE cases was determined using modified Western blot analysis.

Results: Fourteen of the 16 Canadian BSE cases were C type, 1 was H type and 1 was L type. The Canadian H and L-type BSE cases exhibited size shifts and changes in glycosylation similar to other atypical BSE cases. PK digestion under mild and stringent conditions revealed a reduced protease resistance of the atypical cases compared to the C-type cases. N terminal- specific antibodies bound to PrPres from H type but not from C or L type. The C-terminal-specific antibodies resulted in a shift in the glycoform profile and detected a fourth band in the Canadian H-type BSE.

Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan. This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada. It also suggests a similar cause or source for atypical BSE in these countries.

Wednesday, August 11, 2010


Thursday, August 19, 2010


Thursday, August 19, 2010

SCRAPIE CANADA UPDATE Current as of 2010-07-31 The following table lists sheep flocks and/or goat herds confirmed to be infected with scrapie in Canada in 2010. Current as of: 2010-07-31


Surveillance: We've looked at all the groups you're supposed to look at for BSE in all the high-risk categories of the downers, etc. We've looked at about 20,000 for the last two years. We should go higher. We've had the same feed ban date as Canada. We do have a few different exceptions.

We've done formal risk assessments—one by the USDA, one by the European Union, and one by Harvard. Harvard's assessment was the most extensive. They looked at the potential pathways. They found that ,although US is resistant to BSE, there is still a potential for a low animal and human exposure. We still allow the use of high-risk material in the US—brain, spinal cord, and advanced meat recovery. Advanced meat recovery is the process where the bones will go through a machine to remove more muscle tissue. The allows some potential exposure if you have BSE infectivity in the system because the spinal column (even if you remove the spinal cord) still has dorsal ganglia that could be incorporated into AMR. That can still introduce infectivity into the AMR product.

Harvard found the feed ban is key to protection and that the leaks will allow amplification, at least in pockets. Why is the risk not zero? Science, trading patterns, existing regulations and human error all constitute a risk. The US, like Canada, does not have dedicated facilities or transport.

The UK imports into the US. There were 496 total, and 173 of the UK imports could have entered the US feed system. People don't like to hear this, but it's possible that one of the UK imports in the US entered the animal feed system and was exported to Canada. That's a possibility, because they import 50% of their feed from the US.

From 1994, we imported 11 million head of cattle from Canada. Most of these were feedlot animals for slaughter, but there were about 500,000 breeding animals. A number of Canada’s cull cows were slaughtered here and could have introduced infectivity into our system. Even today we have Canadian imports in the country, breeding animals that were brought in prior to the ban and reside here.

We have feed ban exemptions: plate waste, poultry litter. We still allow that if it comes off a human plate, or if it's trimmings, it can be palletized and fed to ruminants. That might be a small amount, but it could allow spinal cord in certain cuts to be fed back to ruminants. Poultry litter or feather meal could be significant. Poultry is getting quite a bit of ruminant material in the US because it cannot go back to ruminants. Poultry and pigs are getting a substantial amount. Poultry litter is not only what passes through the chicken, but think about how chickens eat. They spill a lot on the floor. That stuff is still allowed to be fed back to cattle. That's a direct break in the ban, except that it's legal. Ruminants are getting ruminant material.

Unfiltered tallow: tallow is a lipid material. However, if it's not filtered, there are protein residues. That's meat and bone meal. That's allowed to be fed, so that's another legal exception where you can feed ruminant meat and bone meal through unfiltered tallow. We don't have an SRM ban and the 40 animals are the ones that if you have the agent, they introduce the most infectivity back into the animal food chain when they're rendered.

What's our on-farm compliance? We really don't know.


Harvard BSE Risk Assessment MY comments/questions are as follows ;

1. SINCE the first Harvard BSE Risk Assessment was so flawed and fraught with error after the PEER REVIEW assessment assessed this fact, how do you plan on stopping this from happening again, will there be another peer review with top TSE Scientist, an impartial jury so-to-speak, to assess this new and updated Harvard BSE/TSE risk assessment and will this assessment include the Atypical TSE and SRM issues ?

*** Suppressed peer review of Harvard study October 31, 2002 ***

Sunday, February 14, 2010

[Docket No. FSIS-2006-0011] FSIS Harvard Risk Assessment of Bovine Spongiform Encephalopathy (BSE)


Dr. Thornsberry: What about blood meal?

Dr. Detwiler: Although there's not been infectivity found in cattle blood, the one thing we have to be concerned about is the stunning method. You can have micro-emboli of brain material in blood, and we do allow the legal feeding of blood meal. You could have a contamination from these emboli. Also the brain drips into the blood.

In the past a stun gun that injected air into the cranium had been used. It was so high pressure that it scrambled the brain, pushed it through the foramen magnum, rippled the spinal cord and went down into the azygous venous system. Big parts of the brain and spinal cord were being found in the heart, the lungs, the liver. The industry has gone away from using this stun gun, but there's no regulation that prohibits it.


Identification and traceability aren’t going to stop the disease, but they are essential for locating herd cohorts and identifying other animals that may have been exposed. OIE requires birth cohorts and progeny of a BSE positive cow to be removed.





PRODUCT Bulk cattle feed made with recalled Darling’s 85% Blood Meal, Flash Dried, Recall # V-024-2007 CODE Cattle feed delivered between 01/12/2007 and 01/26/2007

RECALLING FIRM/MANUFACTURER Pfeiffer, Arno, Inc, Greenbush, WI. by conversation on February 5, 2007. Firm initiated recall is ongoing.

REASON Blood meal used to make cattle feed was recalled because it was cross-contaminated with prohibited bovine meat and bone meal that had been manufactured on common equipment and labeling did not bear cautionary BSE statement.





RECALLING FIRM/MANUFACTURER Rangen, Inc, Buhl, ID, by letters on February 13 and 14, 2007. Firm initiated recall is complete.

REASON Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement.




Terry S. Singeltary Sr. (Submitted question): Monday, April 5, 2010 Update on Feed Enforcement Activities to Limit the Spread of BSE April 5, 2010

Monday, May 12, 2008


Tuesday, July 21, 2009

Transmissible mink encephalopathy - review of the etiology

Saturday, December 01, 2007

Phenotypic Similarity of Transmissible Mink Encephalopathy in Cattle and L-type Bovine Spongiform Encephalopathy in a Mouse Model Volume 13, Number 12–December 2007 Research

Monday, December 21, 2009

Distinct Molecular Signature of Bovine Spongiform Encephalopathy Prion in Pigs

Friday, August 6, 2010

Is the presence of abnormal prion protein in the renal glomeruli of feline species presenting with FSE authentic?

Monday, March 8, 2010

Canine Spongiform Encephalopathy aka MAD DOG DISEASE

Greetings, Another Big Myth about Transmissible Spongiform Encephalopathy, is that TSE will not transmit to dogs. This is simply NOT TRUE. IT is perfectly legal to feed dogs and cats here in the USA bovine meat and bone meal. Canine dementia is real. how many dogs and cats here in the USA are tested for mad cow disease ? I just received this F.O.I.A. request, and thought I would post it here with a follow up on MAD DOG DISEASE. This is a follow up with additional data I just received on a FOIA request in 2009 ;

see full text, and be sure to read the BSE Inquiry documents toward the bottom ;

Friday, August 20, 2010

USDA: Animal Disease Traceability August 2010



Identification and traceability aren’t going to stop the disease, but they are essential for locating herd cohorts and identifying other animals that may have been exposed. OIE requires birth cohorts and progeny of a BSE positive cow to be removed.

Canada implemented what the international scientific committee told them to do: they're taking all these tissues out of the food supply for people. You can't remove the dorsal ganglia, the trigeminal ganglia out of the bony tissues so you have both the skull and veretabral column be SRM. The distal ileum is coming out of all ages.

AMR is one thing the US needs to look at. It's a wide dissemination of nervous tissue in the meat product, especially if the process is not done correctly. Even if you remove the spinal cord, you still have the dorsal ganglia associated with the vertebral column and the dura that protects the spinal cord. It would be prudent for the government to move now on restricting ARM.

Harvard's first model did 1000 runs and found the mean ID-50s to humans was 35. Eleven of these were from brain and spinal cord. Twenty—more than half—were from AMR. In the recent runs with Canada, they had some where the ID-50s were up in the hundreds and, in the worst-case scenario- over 1000. Half of those were from AMR. So even if you remove brain and spinal cord from the human food chain, AMR will still deliver more potential doses of infectivity to the public than brain and spinal cord combined.

Dr. Bartz: Exactly what is AMR? Why does it increase infectivity?

Dr. Detwiler: You put the vertebral column through a machine that beats everything off of it.

Dr. Bartz: So you’re saying that if you pull out the spinal cord, when it goes through the ARM, it's pulling off DRGs and the dura.

Dr. Detwiler: And then that gets incorporated into ground beef and it's widely disseminated. In the United States, food has to be labeled. You wouldn't go to a store and buy something that had brain and spinal cord in it. It would have to be labeled so you would know you were eating it.

Dr. Thornsberry: I don't remember the percentage, but it was over half of all advanced meat recovery material we were manufacturing was going into the commodity-type systems.

Dr. Detwiler: That doesn't have to be labeled AMR, so you don’t know what's in and what's not. That could be incorporated into any mixed meat product. The public would feel betrayed and they wouldn't know what products to avoid because of the labeling requirements. McDonald's has never allowed it in their product, even before BSE risk. They continue to not allow it. I don’t know about the other fast-food chains.

Dr. Thornsberry: It looks like a paste. It doesn't have a consistency and it's got a lot of water in it. It's a paste of junk. You combine that and make a sausage or a salami. The average person wouldn't get a piece of AMR meat, but might get some specialty meat that had AMR in it.

Dr. Detwiler: If it's in ground beef, it has to be done in a smaller percentage. It technically could, in a lower percent, go into some ground beef.

Some of these large dairies are looking for protein sources and they mix their own on-farm. Two practitioners in California told me their dairies are feeding pet food. What goes into pet food?
A lot of the down cows. It never crosses their mind that this could be ruminant material.

The 4D risk is significant. In the Harvard study the model showed that if BSE was circulating in the cattle production system, 1500 ID-50s would come from healthy cattle at slaughter, and 37,000 from the 4D. Think about it. If a cow dies from BSE it is at the end stage disease where the level of infectivity is highest. If there are leaks in the feed ban, this population re-introduce the highest level of infectivity back to your cattle population.

Dr. Spraker: What are the four Ds?

Dr. Detwiler: Dead, dying, down, diseased. They're a lump sum of the animals that don’t make it for human consumption.


However, feeding those dead stock downer cows to children for over 4 years was something they should never ever be able to forget about. dead stock downer cows are the most high risk animal for mad cow disease, and they knew this when the feeding to our children of this product was taking place. the USDA et al via the NSLP fed our children all across the USA, from state to state, the largest beef recall in history, they fed our children DEAD STOCK DOWNER COWS, the most HIGH RISK CATTLE FOR MAD COW DISEASE, they fed them to our children, and hid the largest beef recall in USA history, hid this recall under the guise of 'animal abuse'. then told the parents not to worry because none of the kids had been sick or died from it to date. CJD can incubate for decades. anyway, just wanted to tell you about this, and thank you for what you are trying to do...


Do you actually believe that the USDA et al jumped in on the law suit against Westland/Hallmark, at the time the largest beef recall in USA history, just because a few animals were abused on a video, or to cover their ass, for letting our children, from school district to school district, from state to state, be fed dead stock downer cows.

>>>In the papers, the government alleges the meatpacking plant slaughtered and processed downer cows for nearly four years — from January 2004 to September 2007 — at the average rate of one every six weeks... <<<

Do you actually believe all these schools recalled this meat because of a few cattle being abused, see list ;

FNS All Regions Affected School Food Authorities By State United States Department of Agriculture Food and Nutrition Service National School Lunch Program March 24, 2008 School Food Authorities Affected by Hallmark/Westland Meat Packing Co. Beef Recall February 2006 - February 2008

IF url does not work above, go to this link to find out if any of your children and their school were part of this recall ;

go to this site ;

left hand corner search ;

Hallmark/Westland Meat Packing Co. Beef Recall your should get this ;

1 through 1 of 1 matching documents, best matches first. sort by date 1: Hallmark - Westland SFA Reporting by State - 3-24-2008.xls Lunch Program March 24, 2008 School Food Authorities Affected by Hallmark/Westland Meat Packing Co. Beef Recall February 2006 - February 2008 The U.S. Department of Agriculture ...


Members of The HSUS are also concerned about the meat products provided to their children through the National School Lunch Program. More than 31 million school children receive lunches through the program each school day. To assist states in providing healthful, low-cost or free meals, USDA provides states with various commodities including ground beef. As evidenced by the HallmarkNVestland investigation and recall, the potential for downed animals to make their way into the National School Lunch Program is neither speculative nor hypothetical.


Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.


The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...

PLEASE be aware, for 4 years, the USDA fed our children all across the Nation dead stock downer cows, the most high risk cattle for BSE aka mad cow disease and other dangerous pathogens. who will watch our children for CJD for the next 5+ decades ???


Tuesday, August 24, 2010

USDA Encourages Schools to Take the Healthier

US School Challenge to Help Improve the Nutrition of School Children Nationwide



We have to be careful that the absence of evidence is not evidence of absence, and when we say there's absolutely no scientific evidence. We need to be very careful when we talk to the public, and even producers, to make sure there is scientific evidence, and if there's not, to tell that to the public. A case in point is the UK with the link to human disease. In 1989, some experts said that there was absolutely no scientific evidence that the disease could go to humans. That was a correct statement then, however, it was not the entire story. What should have followed was that there is no evidence to definitively state that BSE could not cross species. The bottom line was that we don’t have much evidence period. We have to be careful of predictions from TSE’s in other species, as these long incubations dieeases are like wolves in sheep’s clothing.

Prevention with adverse action or significant cost is very difficult to sell. I spent my whole career with APHIS trying to sell prevention—first with Scrapie and then with BSE. If BSE didn't go to humans, I don't think we'd ever have sold the feed ban. Now the industry is glad we did. Failure to prevent is an easy target, but how do you measure success? Regulations: if people believe it will protect them, you don't need much compliance. If people aren't cognizant or don't realize how it will protect them, you need a lot of compliance. Driving is a good example. People believe seat belts will at least reduce fatality. You don't need a cop in your car to wear your seatbelt. But speeding is a different story. How many people drive the speed limit? By statistics, the higher the speed limit, the more you increase your chance of fatality. We need to know how much your producers and clients believe in the feed ban.

Disposal: positive solutions for one problem may create more expensive problems. It's easy to say "ban everything," but then what do you do with it? That's something we need to educate the public on. It's not as easy as it appears. You create environmental problems.

Dr. Keller: Do you know what they're doing with the rendered product? We heard at one time they were using it in the UK to make asphalt.

Dr. Detwiler: There are a lot of different things now. Some places are combining it with concrete and asphalt because it's a binder. Most of it gets rendered first and then the rendered material is used. They're using it as a fuel source—the meat and bone meal and the tallow. The tallow, apparently, burns well. Some of the rendering plants in California converted their systems when energy prices rose and ran off their own tallow.

There's a cement company in the US that wants to burn meat and bone meal in their kilns. Temperatures will go up into the thousands of degrees.

Regaining scientific credibility and public confidence may require extreme measures. That's why I think it's so important for the countries not to lose public confidence. Japan lost it, and they've had to take extreme measures, like testing every cow for human consumption.

Dr. Thornsberry: Two years ago, I worked as a consultant in Missouri and I had a couple of clients who owned large swine operations. They were cleaning out their swine feed bins and feeding it to their cows. They were feeding for a large corporate entity, and that entity would remove a group of hogs and they might leave two or three tons of hog feed. The hog feed contained meat and bone meal. It wasn't a real high level. Sometimes it was porcine meal and sometimes it was bovine, but it was in there. I got in contact with the state veterinarian and it went up to the FDA level concerning the feeding of this and the feeding of poultry litter. I asked if they'd made any rulings about the feeding of poultry litter because I knew that 5% of our feed is lost without ever being consumed. The FDA veterinarian’s comment to me was, "Dr. Thornsberry, until there are dead bodies lying in the street, you will not see a change made on the feeding of poultry litter."

I said, "You know there's a potential epidemiological link between the spread of this disease and the feeding of poultry litter, and you're telling me you have to have dead bodies before you make a ruling on it."

He said yes. What's going on with our government?

Dr. Thornsberry: We need to put the pressure on.

Dr. Detwiler: That's right, and there are different entities that are saying this to the government. The Food Marketing Institute, the chain restaurants, do have a position statement they've put together that say they'd like to see the exemptions gone. They feel there are reasons to close the loopholes.

Dr. Thornsberry: I got a memo this summer that Canada agreed not to use AMR from that point on, but it is not prohibited in Canada.

Dr. Detwiler: Right, and that's crucial. Vertebral column is considered a risk material and it cannot be used. The United States has not done that. We're testing products to see if evidence of nervous tissue can be found, but that's not every product. It's done on a random basis by FSIS. We are still allowing AMR.


Thursday, April 9, 2009

Docket No. FDA2002N0031 (formerly Docket No. 2002N0273) RIN 0910AF46 Substances Prohibited From Use in Animal Food or Feed; Final Rule: Proposed

Monday, August 17, 2009

FDA asked to ban poultry litter from feed AGAIN 17 Aug 2009 Ban that Poop !



Dr. Keller: My focus is mainly on questions I have from a state perspective. Although I had about 10 years of veterinary practice experience, my education, with respect to prions, began when I started working for the State of North Dakota in ~1997. Serving as ND’s Designated Scrapie Epidemiologist (DSE) and working with their mandatory Chronic Wasting Disease (CWD) surveillance program, has further increased my appreciation for regulatory challenges associated with TSEs.

Recently, state animal health officials have had the task of drafting comments for the proposed BSE rule, which attempts to address ‘minimal risk countries.’

Background: In ND, the North Dakota Board of Animal Health is charged with protecting the health of domestic animals and also non-traditional livestock. In our state, that includes everything from captive birds to farmed cervids, to lions and tigers and bears. When in a state regulatory position, these responsibilities are not optional, they are required of animal health officials by statute. We are also to prevent escape and release of animals injurious or competitive with agriculture, horticulture, forestry, and other natural resource interests; thereby addressing potential environmental concerns.

We're also charged with taking any steps necessary to control, suppress, eradicate, any and all contagious and infectious diseases. Since prion diseases are indeed considered infectious, they fall under that statute. The State Veterinarian also has the responsibility, if warranted, to quarantine domestic animals and non-traditional livestock. He is to regulate and prohibit arrival or departure from our state of any animals that may be exposed or infected with the disease. Where this could get interesting, is when a state doesn't think the federal regulations are protecting the state’s animal health or is not responsive enough in addressing urgent concerns.

Also, it is very difficult trying to regulate prion diseases when you have limited ‘official live animal tests’ available, such as are available for TB and Brucellosis where you can get more definitive answers quickly. In that situation, prevention is always the best policy.

The industry groups and state agencies need to have a clearer understanding of the prion agent, its pathogenicity, and how it's transmitted so that more useful comments can be submitted on proposed rules.

We need to be concerned about what is an ‘acceptable risk’ of having possible disease transmission to other animals. We also cannot over look the economic damage done by diseases. Look at what one case of BSE did to Canada from an economic standpoint! Another area of responsibility we are charged with, is addressing zoonotic diseases. BSE is one prion disease that is currently considered to be zoonotic.

We have zero tolerance in this country for fecal contamination of our food, so what are we going to determine is an ‘acceptable risk’ for BSE contamination? And if we do allow animals in from countries where there is a risk, what are the mitigating factors or measures that need to be taken? It is my opinion that we need to have extensive measures in place to prevent the introduction of the disease and to maintain the identity of animals from other countries, even if they are only considered to be of ‘minimal risk’.

When we talk about identifying a country as minimal risk because they've had only one case, could this then be extrapolated to other countries? We may end up comparing apples and oranges though. For example, if we have a country in Europe that has one case of BSE, it's not really the same because it's on a different continent with different neighbors. We may not even be fully familiar with the extent of their country’s animal movements or the quality of their surveillance.

Dr. Detwiler: That's a very good point. This rule will allow other countries to apply for minimal-risk status, and I can tell you there are countries other than Canada that have only one case—Greece, Austria, Finland—that have much higher surveillance levels and have had measures in place a lot longer. So this is a reality that this situation could happen.

Dr. Keller: Those countries are watching the situation closely and may be waiting to make their application should the proposed BSE rule be approved as is.

So what would happen if the US found one case of BSE? In our department, there would be immediate attention to what we would say to the producers and to the consuming public. We would need to have factual information available to address food safety concerns. How would we do that? We would need to be able to say we were doing a thorough epidemiologic investigation, and quickly get information back to consumers and our international trading partners as it became available. Two critical actions need to be done: country of origin labeling through maintenance of import identification of live animal and products and identification of individual animals. Another question that needs to be posed is which is easier and more cost effective to do first? There is identity on animals that come into this country, but when we've looked into that, there's no requirement for anyone to maintain that identity. In the past, this country has relied on the use of the brucellosis tags, auction-market back tags and brand inspection. But this does not allow for complete tracking of animals. Especially as the Brucellosis program winds down. There is an obvious need for individual animal identification.

The tattoos that have been suggested as a way to track animals long-term are not a fail-safe method. Everyone has their own idea of what a tattoo should be, what type of ink to use, etc. The reality is, you could have a very good tattoo but it’s not user-friendly. We'd have trouble getting compliance if we asked feedlots to rely on running every animal through a chute to read a tattoo. Running multiple animals down an alley and using RFID readers to collect their information as they run by, might be a workable system. A second form of ID will be needed in case of ID failure.

What's the international standard when we talk about BSE? OIE does not necessarily require seven years since the last case before you can move animals, but OIE has certain requirements for regions to qualify as minimal-risk regions in countries where BSE was identified fewer than seven years ago. For a minimal-risk zone or in a country, these are the things that have to be done: It has to have been based on fewer than one case per million during each of the last four consecutive 12-month periods, within the cattle population that’s over 24 months. These are very specific requirements. Whenever we talk about being consistent with OIE, we really need to consider that, since other countries usually recognize the status assigned by the OIE.

What are the consequences of being more lenient than international standards? It could be used in the marketplace against us and thus lead to a loss of consumer confidence. Other countries would be quick to speak up if they have more stringent standards in avoiding SRMs. When we have a case, it may become a marketing tool for another country.

When our standards are lower, we tend to be the country that would be exposed to the movement of animals that are at risk for bringing in BSE. We could have a ripple effect where we would have loss of consumer confidence, loss of markets, and devastation to the US cattle industry.

If we have another country that's not using SRM and we're looking at identifying that country as a minimal risk area, but we bring in animals that they're not using SRMs from, and the US is still allowing use of SRMS, will that not possibly affect consumer confidence in this country or give our trading partners a reason to question the rationale?

Dr. Detwiler: How about the animals we have now? As I mentioned, if breeding animals were north of the border and they went to slaughter like the cull dairy cows, they'd have their SRMs removed to protect the Canadian public. Below the border, those same animals do not have their SRMs removed.

Dr. Keller: I agree. The number of Canadian birth cohorts you refer to that have entered the US is significant and has not yet been addressed by APHIS. There again, another country could be quick to point out the lack of attention by our epidemiologists to that group of animals, should we ever have a case of BSE in a US born and raised bovine. The main point is that we need to have a standard. The list of SRMs has expanded through research, and I think we’re hearing today that it’s possible even more SRMs may be added. Whatever the list of SRMs is, it needs to be consistent among countries, and the OIE needs to define what the SRMs are.

Obviously there's going to be resistance to taking additional precautions due to costs, but the costs will be even greater and farther reaching if we don’t. We need to be proactive on this issue, not reactive.

The feeding of feather meal is also a major concern. Does feather meal risk increase when you’re moving animals in that are from minimal-risk countries? I believe it would be a potential route of amplification of the prion in our ruminant feed supply. The Harvard Risk Assessment warned against it.

Dr. Schuler, the ND State Veterinarian discovered that in the proposed BSE rule, where they use the terminology "designated feedlot," that it means only the feedlot name listed on a health certificate. It does not mean that the animals going to a designated feedlot are actually going to go to slaughter immediately under a verified protocol. When animals from another country go to a designated feedlot, there's nothing to prevent their tags from being removed and animals being deviated out of the slaughter channel they were originally intended for.

Dr. Detwiler: How did they ever identify what animals ___________________

Dr. Keller: That's a very good question, and it goes back to "what is a designated feedlot?" and "why doesn’t the ID have to be maintained on those animals?" Actions must be taken to address the need for maintenance of ID.

Dr. Thornsberry: We're required in the state of Nebraska to write on the health certificate that these animals are for feeding purposes only and must go to slaughter. But that doesn’t mean that they do.

Dr. Detwiler: A lot of the feedlots will come in and remove the ear-tags and put their own lot tags in order to make a consistent lot, so you lose that ID. That was a problem when the US wanted to investigate what animals were already in feedlots. There's no regulation for that animal to retail that ID.

Dr. Thornsberry: I thought there was, for disease control.

Dr. Detwiler: There might be for Mexican steers, but not others.

Dr. Keller: Most people are not aware that all state animal health officials know from the health certificates, is the first point of destination. For example, feedlot heifers might be brought in from another country and when the feedlot manager discovers some of them are bred, they may be pulled out to be sold as breeding animals and no one may ever know.


Tuesday, July 13, 2010


AUSTRALIAN QUESTIONNAIRE TO ASSESS BSE RISK (OIE) Terrestrial Animal Health Code, 2009 and USA export risk factor for BSE to Australia

Saturday, August 14, 2010


US denies it's illegally sending beef to Australia ?

Friday, 13/08/2010

Saturday, June 19, 2010


Sunday, August 15, 2010



Environmental Contamination

We're finding out on a smaller scale with CWD and Scrapie that environmental contamination is becoming a big concern. It's something we’ve never had to deal with. Even with anthrax, we never had as much interest like we’re seeing with prions. If potential environmental contamination is a problem, then how do you safely dispose of suspect animals? It takes a lot of time and communication with the health department and the landfill owners in trying to get everybody to a comfort level. Legal concerns do need to be addressed.

It is a ripple effect. You may have feedlot contamination, and then you have all the water that ran off. In many of these large feedlots, they're using that water run-off to irrigate fields nearby.

Unfortunately, perception often wins over science in these situations, whether it is a real risk or not!


Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

T.A. Nichols,1,2 Bruce Pulford,1 A. Christy Wyckoff,1,2 Crystal Meyerett,1 Brady Michel,1 Kevin Gertig,3 Edward A. Hoover,1 Jean E. Jewell,4 Glenn C. Telling5 and Mark D. Zabel1,*

1Department of Microbiology, Immunology and Pathology; College of Veterinary Medicine and Biomedical Sciences; Colorado State University; Fort Collins, CO USA; 2National Wildlife Research Center; Wildlife Services; United States Department of Agriculture; Fort Collins, CO USA; 3Fort Collins Utilities; Fort Collins; CO USA; 4Department of Veterinary Sciences; Wyoming State Veterinary Laboratory; University of Wyoming; Laramie, WY USA; 5Department of Microbiology, Immunology, Molecular Genetics and Neurology; Sanders Brown Center on Aging; University of Kentucky; Lexington, KY USA Key words: prions, chronic wasting disease, water, environment, serial protein misfolding cyclic amplification Abbreviations: CWD, chronic wasting disease; sPMCA, serial protein misfolding cyclic amplification; PrPC, cellular prion protein; PrPSc, disease-related, misfolded murine PrP; PrPCWD, disease-related, misfolded cervid PrP; PrPRES, protease-resistant PrP; FCWTF, Fort Collins water treatment facility

Chronic wasting disease (CWD) is the only known transmissible spongiform encephalopathy affecting free-ranging wildlife. Although the exact mode of natural transmission remains unknown, substantial evidence suggests that prions can persist in the environment, implicating components thereof as potential prion reservoirs and transmission vehicles.1-4 CWD-positive animals may contribute to environmental prion load via decomposing carcasses and biological materials including saliva, blood, urine and feces.5-7 Sensitivity limitations of conventional assays hamper evaluation of environmental prion loads in soil and water. Here we show the ability of serial protein misfolding cyclic amplification (sPMCA) to amplify a 1.3 x 10-7 dilution of CWD-infected brain homogenate spiked into water samples, equivalent to approximately 5 x 107 protease resistant cervid prion protein (PrPCWD) monomers. We also detected PrPCWD in one of two environmental water samples from a CWD endemic area collected at a time of increased water runoff from melting winter snow pack, as well as in water samples obtained concurrently from the flocculation stage of water processing by the municipal water treatment facility. Bioassays indicated that the PrPCWD detected was below infectious levels. These data demonstrate detection of very low levels of PrPCWD in the environment by sPMCA and suggest persistence and accumulation of prions in the environment that may promote CWD transmission.


CWD has been endemic in the area for forty years, and it remains unclear how long prions can persist in the environment. If persistent for at least several years, CWD prions deposited into the environment from thousands of infected carcasses may accumulate on soil and vegetation such that it can be washed into surface water draining the basin during snowmelt or rainstorms. Symptomatic and asymptomatic positive animals can also contribute to environmental CWD load via biological materials such as saliva, blood, urine and feces.5-7,32,36,38 Deer and elk defecate approximately 900,000 kg of feces and urinate approximately 14 million liters of urine in the area immediately surrounding the Cache la Poudre river per year.39-42 Although urine and feces likely contain much lower prion loads than blood or saliva, the sheer amount of excreta may contribute significantly to overall environmental prion contamination. The data presented here demonstrate that sPMCA can detect low levels of PrPCWD in the environment, corroborate previous biological and experimental data suggesting long term persistence of prions in the environment2,3 and imply that PrPCWD accumulation over time may contribute to transmission of CWD in areas where it has been endemic for decades. This work demonstrates the utility of sPMCA to evaluate other environmental water sources for PrPCWD, including smaller bodies of water such as vernal pools and wallows, where large numbers of cervids congregate and into which prions from infected animals may be shed and concentrated to infectious levels.

see full text ;

Wednesday, October 14, 2009

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area


Here's an example of a situation we dealt with in our state. A wild deer was shot in a state that has areas endemic with CWD. This animal was harvested just outside of that area. We received a call that this animal had tested positive. The brain had been pulled in that state, but the carcass was allowed to leave with the hunter before the results were reported. By that time, the hunter had taken the meat to a ND processor for final processing and packaging. Then we had to tell the processing plant that they'd had a CWD-positive animal go through their facility and we gave them advice on a recommended cleaning process.

Dr. Bartz: What is the recommended cleaning process?

Dr. Keller: There is no ‘officially approved’ disinfectant for surface cleaning, but strong chlorine solutions, sodium hydroxide or Environ LPH have been recommended.

Dr. Thornsberry: Steam cleaning is part of the process.

Dr. Keller: There has been discussion about the potential approval of Environ LPH for surface cleaning.

Dr. Detwiler: Rick Race has a publication coming out on the different versions of the LPh. The company's supposed to come back out with the old formulation. It's not as corrosive.

Dr. Spraker: When you use it, hold your breath.

Dr. Keller: Another concern I have that's been talked about today already is ‘what is the infectious dose’ and how does that affect the incubation period? We have been focusing on animals, but I know that human health concerns usually supercede animal health concerns in our state.

What's at stake? Supposedly an estimate came out of Canada saying they were still losing $10 million per day. Extrapolating that to the number of cattle in our country, you could be looking at up to $50 million a day. I think that's a very conservative estimate.

Price of human life: should we be talking money when we're talking about a disease with so many unknowns yet about its pathogenicity and infectivity? It appears we can’t talk about zero tolerance anymore, because prions are here in many forms (normal and abnormal). And we will not ever make all prion diseases just ‘go away’, but we do need to put all the effective mitigating factors in place that we can to decrease the introduction and amplification of prion diseases. We need to look at what we can do to ‘prevent’ and then also be ready to deal with the disease if needed.

Dr. Detwiler: I went through one of the biggest cull cow plants up in Canada. They have to do the full SRM—the vertebral column and everything. I asked what it cost to implement that and it's about two cents per pound. That's really not much when you consider the ramifications.

Dr. Keller: If there are going to be costs, they usually trickle down in the cattle business to the producer. But there's probably not a producer who wouldn't spend a few cents to save his industry and assure his customer about the safety of the final product. From the estimates I’ve read, I don’t think cost is as big an issue as some would like us to believe.

Dr. Thornsberry: If the USDA decides to open the border the first of March with no restrictions, does North Dakota have the authority to turn away Canadian cattle?

Dr. Keller: We cannot stop animals coming through our state, but we could prevent them from unloading in North Dakota.

Dr. Thornsberry: So some state along the border could put a stop to cattle coming into the state to stay. The interesting thing about Missouri, where I live, is that Canada will not allow us to export any cattle. We are a southern state with endemic Anaplasmosis and we have potential blue tongue virus infection in our cattle herd. They have all these restrictions based on those two disease control programs, but yet the government is going to force us to take cattle from Canada. Our state veterinarian is under the impression that, if they open the border, there's no way we can restrict them coming in. In Missouri, it's a federal rule. My understanding was that the state veterinarian could make a ruling that because of disease control, nothing could come in to Missouri.

Dr. Keller: I'm really not the person to answer this from a legal perspective, but we've always been counseled that state laws could be more restrictive than federal laws.

Dr. Detwiler: If you recall some of the conference calls where the states had more restrictive rules, the federal government said they would challenge those in court.

Dr. Thornsberry: California has always been able to do that for years, and everybody seems to abide by it.

Dr. Detwiler: Our attorney says that's wrong; they can't. I've heard it both ways. I've heard it from the federal side that yes, you can be restrictive on some diseases, and then they say no on others.

Dr. Thornsberry: I'd like Dr. Detwiler and Dr. Keller to comment on the Harvard risk assessment. The USDA is kind of using that as a carte blanche for opening up the border to Canada, and I think they've already made their mind up. Yet the Harvard risk assessment, if you get into the depth of it a little bit, says that yes, there is an inherent risk of bringing prion-related diseases into this country if the border is opened. Nobody can say that risk is not there. What we’re saying is if it does come in, we have enough safe-guards in place to contain it. That one case in Japan created the loss of 40% of their demand for beef products overnight, and it lasted for several months until they instituted the program to test every animal. I'm not sure we'd have that much of a ramification. However, just saying we can identify the case is not sufficient. Our government should be more oriented toward preventing a case from ever coming rather than letting us figure out how to deal with it once it gets here.

I have a meat plant in Missouri and I have a zero tolerance for Listeria spp., for E. coli O157:H7, and Salmonella, which are sometimes fatal to children and older people. Everyone else survives. If they find that in my plant, I'm shut down until I can prove to USDA that it's not there. And yet we're going to open up our borders and allow a disease to come through that's 100% fatal if a human being should contract the disease. There's an inconsistency in the regulations concerning these animal diseases. One of the comments we're probably going to make to the USDA as a veterinary group, is that the Harvard risk assessment is fine, but once one case is here and identified, we now have potentially seeded large areas with prions. And we know they exist forever. How should the livestock industry view the Harvard risk assessment?

Dr. Keller: I think we need to look at the big picture. There are bits and pieces that people quote from the HRA, but even if you look at the executive summary of the update, there are significant things it says. It's true that the United States is robust and resistant. If the disease is introduced, it will go away because of the system. Other countries have demonstrated that by feed bans. But it also says we're not totally resistant to the introduction, and that if you look at the possible scenarios, it could potentially be a 20-year decline of the agent. It won’t be like it's here today and gone tomorrow. That's one thing that's very significant—to say that you have to expect a 20-year period to eliminate the agent.

The other thing is that there are weaknesses in the system, and it's so important that we don't have high risk SRMs being introduced into our food supply, because if the agent is in the United States, however small there's the perception of a potential public health risk. And, the HRA indicated that there is definitely a potential for further transmission to animals if there are leaks in the feed ban.

The most significant item is that, in the worst-case scenario, if the agent comes from Canada, it's below the level of detection of the USDA's current surveillance system.

Dr. Thornsberry: That's very significant. From an epidemiological standpoint, it blares out. It asks, “Why would you make this decision with the current level of surveillance that we have in this country?”

Dr. Detwiler: To me, the concern is to look at what minimum risk is. Unless it's further defined, how do you look at all the other countries? Some have never been evaluated. Where do they fall in the scheme of things? Those are concerns I have. We also really need to be aware that the risk set a precedent for the US.

Dr. Keller: We know we're at risk for having our own case of BSE here in the US, but I don't think two wrongs make a right. We need to be proactive in getting something done to identify animals as they come in, if they do come in. We need to be able to track animals that are considered minimal risk. We need to hold all countries, including ourselves, to a standard to determine prevalency of all diseases, including prion diseases. I don’t see why we would accept animals from other countries until that is done! It's easy to say you're free of something if you're not adequately testing for it. We've seen that happen with other diseases.

Dr. Detwiler: I'll play devil's advocate. If the US found a case tomorrow, what would we ask of the world? I think that's valid to ask. It's valid to turn the mirror back on yourself.

Dr. Thornsberry: I guarantee you that we would immediately have individual animal ID and it wouldn’t be two years later.

Dr. Keller: And it probably would not be ID that's initially acceptable to the industry. Producers need to realize that if they don’t get involved, it will become mandatory and then they will no longer have the opportunity for producer input.

Dr. Thornsberry: It's almost in the process of being mandated now. I sat on that task force. We're just months away. July 1, 2004, we're supposed to issue premise IDs to every farm in the nation. By the first of January, 2005, we're supposed to have some sort of mandatory identification in place, probably electronic. Right now they have no funds to do that, nor have they been given permission, but they say that, because of disease control, they have the right to mandate this program now.

The other issue that comes up is the concept of country-of-origin labeling. At the time the Canadian BSE cow was identified, I did some investigation at Sterling, Colorado, and a few other packing plants that were taking in Canadian beef. There were over 500,000 pounds of Canadian-bred meat out of two or three different plants in the Colorado area that were in the food chain and could not be identified. Once the animal was brought into the plant and slaughtered, that carcass just went right down the chain with all the others. There was no way to identify where that meat went. If the government at that time had wanted to put a retention on Canadian meat, they'd have had to retain a whole bunch of our meat at the same time. That's been one of the strong arguments for country-of-origin labeling, at least to maintain some ability to track that carcass past the point that it's slaughtered. Right now we don’t have that capability. Once it receives that USDA stamp, it's over. That's an issue that will have to come into play for disease control concerns.

We already have, as of the first of July, a country-of-origin labeling program for Japan and South Korea to guarantee to them that no Canadian meat will make it into their country through our system. But our consumers don’t have the same choice. I think that's a travesty in our industry that we can’t offer American consumers a choice. If we can offer it to Japan's consumers and South Korea's consumers, it seems only logical we should be able to offer it to US consumers, but we do not.


Name: Terry S. Singeltary Sr. Date: Jan 26, 2007

Dear Terry S. Singeltary Sr.

My name in Seoungwon Lee and I work for National Assemblywoman (MP) Sang-Jeong Sim, in South Korea. Below is a message from Mr. Kwon. Please get back to us regarding the letter.

Thank you.

Seoungwon Lee Legislative Assistant National Assembly Republic of Korea

Dear Terry S. Singeltary Sr.

Greetings from Korea.

I have learned about what you and your family have been through a internet. Being the father of a small family, I can only imagine the sense of loss that you and your family still must feel regarding your mother.

Through the internet, many people here in Korea have learnt about the story of your family and it has created a great deal of concern. Your experience had particular relevance for the citizens here, for the Korean government, in connection to the free trade agreement it is negotiating with the United States, is about to restart the sale of the unsafe American beef to the general public.

The Korean government has already imported the first load American beef and is currently going through the inspection period. There has been a great deal of controversy regarding the safety of these products, and a precipitous increase in public interest regarding the causes and symptoms of vCJD.

It is in this context that we are preparing a session together with National Assembly members and relevant NGOs to hear from those who have had direct experience with the human variant of BSE. We are very interested in hearing about the symptoms that your mother showed, your views on the response from the US government to the many deaths that resulted from this disease, the reaction from the general public, and any other area that you would wish to speak about. There would also be experts and academics in the area to speak at the session as well. We believe that it would greatly contribute to raising awareness about the issue, as well as help politicians and civic activists to consider the repercussions of the beef import issue.

We would like to request your help in this regard. We are planning for the session to be held in Seoul on the 23rd of this November. We would very much like to have you present in order to help prevent such tragic incidents from happening in Korea. We would, of course, pay for the trip and accommodations for the duration of your stay. If you were to participate, we could also meet with members from the agricultural committee of the National Assembly and from other related organizations to urge more interest to the issue.

Please do not hesitate to offer suggestions or ask us any questions that you might have. We look forward to a positive response and to meeting you in Seoul.

Thank you.

Sincerely, Sim Sang-Jeong

Head of the Democratic Labor Party Parliamentary Committee on the Korea-US FTA Member of the National Assembly Republic of Korea

Friday, April 02, 2010

U.S. beef trade talks to continue but curbs to remain: Japan

Wednesday, February 10, 2010

The Honorable Ms. Kim Min-sun Anti-US Beef Actress Prevails in Court

Terry, Texas, January 09, 2010 04:39 Singeltary to Senator Pat Roberts


Senator Pat Roberts today sent the following letter to Tiawan’s President Ma Ying-jeou:

The United States has implemented a series of safety standards that provide for safe and delicious beef domestically and for our international markets. The OIE classified the United States as a “controlled risk” for the presence of BSE. This designation confirms that U.S. beef is safe to consume and export, consistent with OIE guidelines. In short, U.S. beef is safe. It is far past time to ensure a commercially viable and predictable market for U.S. beef and allow consumers access to safe and affordable products.



WITH all due respect, U.S. Senator Pat Roberts knows not what he speaks of, or just does not care, trade, trade, trade.

DON'T believe me, ask the Nobel Peace Prize winner on the PRION Stan Prusiner about the prion and trade ;

LET"S look at some facts about BSE, CJD, and the OIE ;

The most recent assessments (and reassessments) were published in June 2005 (Table I; 18), and included the categorisation of Canada, the USA, and Mexico as GBR III. Although only Canada and the USA have reported cases, the historically open system of trade in North America suggests that it is likely that BSE is present also in Mexico.


(Adopted by the International Committee of the OIE on 23 May 2006)

11. Information published by the OIE is derived from appropriate declarations made by the official Veterinary Services of Member Countries. The OIE is not responsible for inaccurate publication of country disease status based on inaccurate information or changes in epidemiological status or other significant events that were not promptly reported to the Central Bureau,

Docket APHIS-2006-0026 Docket Title Bovine Spongiform Encephalopathy; Animal Identification and Importation of Commodities Docket Type Rulemaking Document APHIS-2006-0026-0001 Document Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions, Identification of Ruminants and Processing and Importation of Commodities Public Submission APHIS-2006-0026-0012 Public Submission Title Comment from Terry S Singletary

Docket APHIS-2006-0041 Docket Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived from Bovines Commodities Docket Type Rulemaking Document APHIS-2006-0041-0001 Document Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived From Bovines Public Submission APHIS-2006-0041-0028 Public Submission Title Comment from Terry S Singletary


THE USA is in a most unique situation, one of unknown circumstances with human and animal TSE. THE USA has the most documented TSE in different species to date, with substrains growing in those species (BSE/BASE in cattle and CWD in deer and elk, there is evidence here with different strains), and we know that sheep scrapie has over 20 strains of the typical scrapie with atypical scrapie documented and also BSE is very likely to have passed to sheep. all of which have been rendered and fed back to animals for human and animal consumption, a frightening scenario. WE do not know the outcome, and to play with human life around the globe with the very likely TSE tainted products from the USA, in my opinion is like playing Russian roulette, of long duration, with potential long and enduring consequences, of which once done, cannot be undone. These are the facts as I have come to know through daily and extensive research of TSE over 9 years, since 12/14/97. I do not pretend to have all the answers, but i do know to continue to believe in the ukbsenvcjd only theory of transmission to humans of only this one strain from only this one TSE from only this one part of the globe, will only lead to further failures, and needless exposure to humans from all strains of TSE, and possibly many more needless deaths from TSE via a multitude of proven routes and sources via many studies with primates and rodents and other species.

MY personal belief, since you ask, is that not only the Canadian border, but the USA border, and the Mexican border should be sealed up tighter than a drum for exporting there TSE tainted products, until a validated, 100% sensitive test is available, and all animals for human and animal consumption are tested. all we are doing is the exact same thing the UK did with there mad cow poisoning when they exported it all over the globe, all the while knowing what they were doing. this BSE MRR policy is nothing more than a legal tool to do just exactly what the UK did, thanks to the OIE and GW, it's legal now. and they executed Saddam for poisoning ???

go figure. ...

Docket APHIS-2006-0041 Docket Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived from Bovines Commodities Docket Type Rulemaking Document APHIS-2006-0041-0001 Document Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived From Bovines Public Submission APHIS-2006-0041-0028.1 Public Submission Title Attachment to Singletary comment

January 28, 2007

Greetings APHIS,

I would kindly like to submit the following to ;


Monday, November 23, 2009



Can anyone blame Taiwan for banning USA beef? I applaud Taiwan for standing up to the USA and their junk science, and trying to protect their consumers. The USA has been covering up mad cow disease for over a decade. The OIG and the GAO have proven, time and time again, the failures and flaws with the USA BSE surveillance, and then they hide behind the infamous triple firewall of the failed, partial and voluntary feed ban of August 4, 1997. This was nothing but ink on paper, it was never enforceable. nope, all the USA does is blame everything on Canada. what they really need to do is stand if front of a mirror and take a good look at themselves. The USDA's NSLP for over 4 years fed dead stock downer cows to our children all across the Nation. These are the most high risk cattle for mad cow disease and other dangerous pathogens. IF the USDA et al are willing to feed this crap to our Children, do you think for one second they would not feed it to the Honorable people of Taiwan? THE USDA/FDA et al ARE the sole reason of Taiwan banning their products. TEST, TEST, TEST !!!

Tuesday, December 29, 2009

Taiwan to resume USA beef ban over mad cow disease threat

Tuesday, November 10, 2009

Surveillance On the Bovine Spongiform Encephalopathy and rabies in Taiwan and USA

Monday, November 30, 2009

Taiwan, USDA, and USA beef, what the consumer does not know, could kill them

snip...see full text ;

Subject: Importation of Whole Cuts of Boneless Beef from Japan [Docket No. 05-004-1] RIN 0579-AB93 TSS SUBMISSION

Date: August 24, 2005 at 2:47 pm PST

August 24, 2005

Importation of Whole Cuts of Boneless Beef from Japan [Docket No. 05-004-1] RIN 0579-AB93 TSS SUBMISSION

Greetings APHIS ET AL,

My name is Terry S. Singeltary Sr.

I would kindly like to comment on [Docket No. 05-004-1] RIN 0579-AB93 ;


Exportation and importation of animals and animal products:

Whole cuts of boneless beef from-


48494-48500 [05-16422]




Tuesday, March 16, 2010



Proof Committee Hansard

RRA&T 2 Senate Friday, 5 February 2010


[9.03 am]

BELLINGER, Mr Brad, Chairman, Australian Beef Association

CARTER, Mr John Edward, Director, Australian Beef Association

CHAIR—Welcome. Would you like to make an opening statement?

Mr Bellinger—Thank you. The ABA stands by its submission, which we made on 14 December last year, that the decision made by the government to allow the importation of beef from BSE affected countries is politically based, not science based. During this hearing we will bring forward compelling new evidence to back up this statement. When I returned to my property after the December hearing I received a note from an American citizen. I will read a small excerpt from the mail he sent me in order to reinforce the dangers of allowing the importation of beef from BSE affected countries. I have done a number of press releases on this topic, and this fellow has obviously picked my details up from the internet. His name is Terry Singeltary and he is from Bacliff, Texas. He states, and rightfully so:

You should be worried. Please let me explain. I’ve kept up with the mad cow saga for 12 years today, on December 14th 1997, some four months post voluntary and partial mad cow feed ban in the USA, I lost my mother to the Heidenhain variant Creutzfeldt-Jakob disease (CJD). I know this is just another phenotype of the infamous sporadic CJDs. Here in the USA, when USA sheep scrapie was transmitted to USA bovine, the agent was not UK BSE—it was a different strain. So why then would human TSE from USA cattle look like UK CJD from UK BSE? It would not. So this accentuates that the science is inconclusive still on this devastating disease. He goes on to state:

The OIE— the International Organisation of Epizootics, the arm of the WTO— is a failed global agent that in my opinion is bought off via bogus regulations for global trade and industry reps. I have done this all these years for nothing but the truth. I am a consumer, I eat meat, but I do not have to sit idly by and see the ignorance and greed of it all while countless numbers of humans and animals are being exposed to the TSE agents. All the USA is interested in is trade, nothing else matters.

Even Dr Stanley Prusiner, who incidentally won the Nobel Health Prize in 1997 for his work on the prion—he invented the word ‘prion’, or it came from him—states:

The BSC policy was set up for one purpose only, trade—the illegal trading of all strains of TSE globally throughout North America, which is home to CBSC, IBSC and HBSC, many scrapie strains and two strains of CJD to date. (please note typo error, those should have read cBSE, lBSE, and hBSE...tss)

I would also like, while I have the opportunity, to explain the beef-off-the-shelves myth. At the first Senate hearing on 14 December, it was explained that the reason why they allowed BSC beef into Australia was the beef-off-the-shelves policy, whereby if we found a case of BSC in Australia they would have to recall all—

Friday, 5 February 2010 Senate RRA&T 3


Senator HEFFERNAN—Which of course is total BS.

Mr Bellinger—Correct. This is written in the FSANZ document—Food Standards Australia New Zealand. Why isn’t this same policy in New Zealand? It is not—it is only in Australia. We are the only country in the world to have this idiotic policy. So we again call for the tabling of the WTO obligations paperwork. We do not believe that exists.

snip...see full text 110 pages ;

for those interested, please see much more here ;


Dr. Spraker: Does the US import a lot of meat from Argentina and South America?

Dr. Thornsberry: They don’t right now. They do import a lot of cooked product. They have so much foot and mouth disease. I've been in a lot of those countries and I don't see that they'll ever have that problem under control.

Dr. Keller: We've had many foreign exchange students at out ranch, and several from South America. They have insinuated that there is a great deal of unrestricted movement between South American countries.

Dr. Thornsberry: I spent time in Venezuela on a ranch with 50,000 mother cows and they couldn’t tell you where those cows were at any one time, period. They have computers and they keep track of things, but the level of technology is much more primitive.

Dr. Keller: Communication indicated that political pressure kept Argentina animal health officials from reporting the FMD case. It was actually producers who encouraged reporting their own FMD case. I am beginning to wonder if in this country, too, it's going to take industry and producers to encourage our officials to do the right thing for US animal health and US agriculture.

Dr. Thornsberry: One group of people we haven't discussed today is the consumers in this country. Over 90% of the meat in the United States is purchased by women. I don't know if the USDA has allowed any input from consumer groups on this subject.

Dr. Keller: We should not needlessly scare the public, but there is a responsibility to take additional precautions in processing if needed. When the education and research information does catch up with the buying and consuming public, they're going to want to know what’s been done to address concerns regarding SRMs and AMR meat.

Dr. Spraker: With CWD, so many men will turn a head in and say they can't bring the meat in the house because the wife wants it tested first.

Dr. Detwiler: We get asked all the time why does the public react so volatily to this? and the only thing that I can figure is that you can't cook it away, you can't detect it with certainty in the live animal, you can’t test the product for it. So the consumer relies on the industry and the government. It's an issue where the consumer lacks control. With E. coli, they know: if you cook it right and feed it to your kids, it's going to be okay. They have some control.

Dr. Bartz: With many infectious diseases, in two weeks, you’re over it and you get on with your life. But if you consume BSE-potentially-tainted beef, you're going to be worried for the rest of your life.

Dr. Thornsberry: In 1994, I spent a month in Spain, Portugal and France, and I know I ate beef when I was there..

Dr. Detwiler: You ate mutton.

Dr. Thornsberry: I ate mutton, I ate pork, I ate pig ears. I ate a lot of traditional Spanish and Portuguese meat, and I ate beef. And Portugal and France have had numerous cases of BSE. So have I been exposed to BSE? My son went with me.

Dr. Spraker: We know how many deaths occur from alcohol and we know how many people die from chewing tobacco. But we're not afraid of those. Why not?

Dr. Keller: It's likely because the use is intentional with alcohol and tobacco.

Dr. Detwiler: The risk communicators will tell you that if you make the choice and take the risk, there's a different kind of perception.

Dr. Thornsberry: This has been an excellent round-table. I know I've learned a lot…

[tape change]

…There does not seem to be very much risk of CWD being transferred to other species except cervids. It hasn't been seen and the chances are not great, although with any prion disease, the risk is possible.

Dr. Detwiler: If we let it go unchecked, we increase the biological load. I think it's prudent for the government to keep the biological load down.

Dr. Spraker: Because we don’t know if, 10 years from now, there will be an emergence of a new strain of CWD with a totally different host range.


J. Virol. doi:10.1128/JVI.01133-10 Copyright (c) 2010, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Environmental Sources of Scrapie Prions

Ben C. Maddison, Claire A. Baker, Linda A. Terry, Susan J. Bellworthy, Leigh Thorne, Helen C. Rees, and Kevin C. Gough* ADAS UK, Department of Biology, University of Leicester, University Road, Leicester, LE1 7RH. UK; Veterinary Laboratories Agency, Woodham Lane, New Haw, Addlestone, Surrey. KT15 3NB. UK; School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington Campus, College Road, Sutton Bonington, Leicestershire, LE12 5RD. UK

* To whom correspondence should be addressed. Email: .

Abstract Ovine scrapie and cervine chronic wasting disease show considerable horizontal transmission. Here we report that a scrapie-affected sheep farm contained widespread environmental contamination with prions. Prions were amplified by Protein Misfolding Cyclic Amplification (sPMCA) from seven of the nine environmental swab samples taken including those from metal, plastic and wooden surfaces. Sheep had been removed from these areas up to 20 days prior to sampling indicating that prions persist for at least this duration. These data implicate inanimate objects as environmental reservoirs of prion infectivity which are likely to contribute to facile disease transmission.

Friday, May 14, 2010

Prion Strain Mutation Determined by Prion Protein Conformational Compatibility and Primary Structure

Published Online May 13, 2010 Science DOI: 10.1126/science.1187107 Science Express Index

Thursday, June 03, 2010

Prion Strain Mutation and Selection John Collinge MEDICINE



Chad Johnson1, Judd Aiken2,3,4 and Debbie McKenzie4,5 1 Department of Comparative Biosciences, University of Wisconsin, Madison WI, USA 53706 2 Department of Agriculture, Food and Nutritional Sciences, 3 Alberta Veterinary Research Institute, 4.Center for Prions and Protein Folding Diseases, 5 Department of Biological Sciences, University of Alberta, Edmonton AB, Canada T6G 2P5

The identification and characterization of prion strains is increasingly important for the diagnosis and biological definition of these infectious pathogens. Although well-established in scrapie and, more recently, in BSE, comparatively little is known about the possibility of prion strains in chronic wasting disease (CWD), a disease affecting free ranging and captive cervids, primarily in North America. We have identified prion protein variants in the white-tailed deer population and demonstrated that Prnp genotype affects the susceptibility/disease progression of white-tailed deer to CWD agent. The existence of cervid prion protein variants raises the likelihood of distinct CWD strains. Small rodent models are a useful means of identifying prion strains. We intracerebrally inoculated hamsters with brain homogenates and phosphotungstate concentrated preparations from CWD positive hunter-harvested (Wisconsin CWD endemic area) and experimentally infected deer of known Prnp genotypes. These transmission studies resulted in clinical presentation in primary passage of concentrated CWD prions. Subclinical infection was established with the other primary passages based on the detection of PrPCWD in the brains of hamsters and the successful disease transmission upon second passage. Second and third passage data, when compared to transmission studies using different CWD inocula (Raymond et al., 2007) indicate that the CWD agent present in the Wisconsin white-tailed deer population is different than the strain(s) present in elk, mule-deer and white-tailed deer from the western United States endemic region.


Susceptibility of Cattle to First-passage Intracerebral Inoculation with Chronic Wasting Disease Agent from White-tailed Deer

A. N. Hamir1, J. M. Miller1, R. A. Kunkle1, S. M. Hall2 and J. A. Richt1 + Author Affiliations

1National Animal Disease Center, ARS, USDA, Ames, IA 2Pathobiology Laboratory, National Veterinary Services Laboratories, Ames, IA Dr. A. N. Hamir, National Animal Disease Center, ARS, USDA, 2300 Dayton Avenue, PO Box 70, Ames, IA 50010 (USA). E-mail: Abstract Fourteen, 3-month-old calves were intracerebrally inoculated with the agent of chronic wasting disease (CWD) from white-tailed deer (CWDwtd) to compare the clinical signs and neuropathologic findings with those of certain other transmissible spongiform encephalopathies (TSE, prion diseases) that have been shown to be experimentally transmissible to cattle (sheep scrapie, CWD of mule deer [CWDmd], bovine spongiform encephalopathy [BSE], and transmissible mink encephalopathy). Two uninoculated calves served as controls. Within 26 months postinoculation (MPI), 12 inoculated calves had lost considerable weight and eventually became recumbent. Of the 12 inoculated calves, 11 (92%) developed clinical signs. Although spongiform encephalopathy (SE) was not observed, abnormal prion protein (PrPd) was detected by immunohistochemistry (IHC) and Western blot (WB) in central nervous system tissues. The absence of SE with presence of PrPd has also been observed when other TSE agents (scrapie and CWDmd) were similarly inoculated into cattle. The IHC and WB findings suggest that the diagnostic techniques currently used to confirm BSE would detect CWDwtd in cattle, should it occur naturally. Also, the absence of SE and a distinctive IHC pattern of CWDwtd and CWDmd in cattle suggests that it should be possible to distinguish these conditions from other TSEs that have been experimentally transmitted to cattle.

second passage is even worse ;

Experimental Second Passage of Chronic Wasting Disease (CWDmule deer) Agent to Cattle

A. N. Hamir, R. A. Kunkle, J. M. Miller, J. J. Greenlee and J. A. Richt Agricultural Research Service, United States Department of Agriculture, National Animal Disease Center, 2300 Dayton Avenue, P.O. Box 70, Ames, IA 50010, USA


To compare clinicopathological findings in first and second passage chronic wasting disease (CWDmule deer) in cattle, six calves were inoculated intracerebrally with brain tissue derived froma first-passageCWD-affected calf in an earlier experiment. Two uninoculated calves served as controls. The inoculated animals began to lose both appetite and weight 10–12 months later, and five subsequently developed clinical signs of central nervous system (CNS) abnormality. By 16.5 months, all cattle had been subjected to euthanasia because of poor prognosis. None of the animals showed microscopical lesions of spongiform encephalopathy (SE) but PrPres was detected in their CNS tissues by immunohistochemistry (IHC) and rapid Western blot (WB) techniques. Thus, intracerebrally inoculated cattle not only amplified CWD PrPres from mule deer but also developed clinicalCNSsigns in the absence of SElesions.This situation has also been shown to occur in cattle inoculated with the scrapie agent. The study confirmed that the diagnostic techniques currently used for diagnosis of bovine spongiformencephalopathy (BSE) in theUS would detect CWDin cattle, should it occur naturally. Furthermore, it raised the possibility of distinguishing CWDfromBSE in cattle, due to the absence of neuropathological lesions and to a distinctive multifocal distribution of PrPres, as demonstrated by IHC which, in this study, appeared to be more sensitive than the WB technique. Published by Elsevier Ltd. Keywords: cattle; chronic wasting disease (CWD); deer; transmissible spongiform encephalopathy (TSE)


Discussion CWD, like all other TSEs, is characterized by a long incubation period, which in deer is seldom less than 18 months (Williams and Young, 1992). In an experimental study of cattle inoculated intracerebrally with CWD from mule deer (first passage), amplification of PrPres was demonstrated in only five of 13 (38%) cattle, after incubation periods that ranged from 23 to 63 months (Hamir et al., 2001a, 2005a). In contrast, all inoculated cattle in the present study were positive for PrPres within 16.5 months. This increased attack rate with shorter incubation periods probably indicates adaptation of the CWDmule deer agent to a new host.


The uniform susceptibility, relatively short incubation, and absence of microscopical lesions in cattle given CWD brain material passaged once through cattle resembled findings in cattle inoculated intracerebrally with the scrapie agent (Cutlip et al., 1997). In that experiment, 100% of cattle died 14–18 months after inoculation with material from the first cattle-passage of a US strain of the scrapie agent; none showed microscopical lesions and all were positive for PrPres.

Sunday, April 12, 2009

CWD UPDATE Infection Studies in Two Species of Non-Human Primates and one Environmental reservoir infectivity study and evidence of two strains

Experimental oral transmission of chronic wasting disease to red deer (Cervus elaphus elaphus): Early detection and late stage distribution of protease-resistant prion protein

Aru Balachandran, Noel P. Harrington, James Algire, Andrei Soutyrine, Terry R. Spraker, Martin Jeffrey, Lorenzo González, Katherine I. O’Rourke

Abstract — Chronic wasting disease (CWD), an important emerging prion disease of cervids, is readily transmitted by intracerebral or oral inoculation from deer-to-deer and elk-to-elk, suggesting the latter is a natural route of exposure. Studies of host range susceptibility to oral infection, particularly of those species found in habitats where CWD currently exists are imperative. This report describes the experimental transmission of CWD to red deer following oral inoculation with infectious CWD material of elk origin. At 18 to 20 months post-inoculation, mild to moderate neurological signs and weight loss were observed and animals were euthanized and tested using 3 conventional immunological assays. The data indicate that red deer are susceptible to oral challenge and that tissues currently used for CWD diagnosis show strong abnormal prion (PrPCWD) accumulation. Widespread peripheral PrPCWD deposition involves lymphoreticular tissues, endocrine tissues, and cardiac muscle and suggests a potential source of prion infectivity, a means of horizontal transmission and carrier state.

Can Vet J 2010;51:169–178

Chronic wasting disease (CWD), an important emerging prion disease of cervids, is readily transmitted by intracerebral or oral inoculation from deer-to-deer and elk-to-elk, suggesting the latter is a natural route of exposure.

Potential Venison Exposure Among FoodNet Population Survey Respondents, 2006-2007

Ryan A. Maddox1*, Joseph Y. Abrams1, Robert C. Holman1, Lawrence B. Schonberger1, Ermias D. Belay1 Division of Viral and Rickettsial Diseases, National Center for Zoonotic, Vector-Borne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, GA *Corresponding author e-mail:

The foodborne transmission of bovine spongiform encephalopathy to humans, resulting in variant Creutzfeldt-Jakob disease, indicates that humans can be susceptible to animal prion diseases. However, it is not known whether foodborne exposure to the agent causing chronic wasting disease (CWD) in cervids can cause human disease. The United States Foodborne Diseases Active Surveillance Network (FoodNet) conducts surveillance for foodborne diseases through an extensive survey administered to respondents in selected states. To describe the frequency of deer and elk hunting and venison consumption, five questions were included in the 2006-2007 FoodNet survey. This survey included 17,372 respondents in ten states: California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee. Of these respondents, 3,220 (18.5%) reported ever hunting deer or elk, with 217 (1.3%) reporting hunting in a CWD-endemic area (northeastern Colorado, southeastern Wyoming, and southwestern Nebraska). Of the 217 CWD-endemic area hunters, 74 (34.1%) were residents of Colorado. Respondents reporting hunting were significantly more likely to be male than female (prevalence ratio: 3.3, 95% confidence interval: 3.1-3.6) and, in general, older respondents were significantly more likely to report hunting than younger respondents. Venison consumption was reported by more than half (67.4%) of the study population, and most venison consumers (94.1%) reported that at least half of their venison came from the wild. However, more than half (59.1%) of the consumers reported eating venison only one to five times in their life or only once or twice a year. These findings indicate that a high percentage of the United States population engages in hunting and/or venison consumption. If CWD continues to spread to more areas across the country, a substantial number of people could potentially be exposed to the infectious agent.

Title: Experimental oral transmission of chronic wasting disease (CWD) to red deer (Cervus elaphus elaphus): early detection and late stage distribution of protease-resistant protein (PrP-res)

Balachandran, A - CANADIAN FOOD INSPCTN AG Harrington, Noel - CANADIAN FOOD INSPCTN AG Algire, James - CANADIAN FOOD INSPCTN AG Souyrine, Andre - CANADIAN FOOD INSPCTN AG Orourke, Katherine Spraker, Terry - COLORADO ST UNIV

Submitted to: Canadian Journal of Veterinary Research Publication Type: Peer Reviewed Journal Publication Acceptance Date: December 1, 2008 Publication Date: N/A

Interpretive Summary: Farmed cervids may be exposed to the prion disorder chronic wasting disease through contact with free ranging or farmed infected Rocky Mountain elk, white tailed deer, mule deer, or moose. This is the first report of experimental transmission of chronic wasting disease to red deer, an economically important agricultural commodity in parts of North America. Brain tissue from infected Rocky Mountain elk was administered by the oral route of red deer. Deer were examined at 18 months after infection for evidence of abnormal prion protein, the marker for the disease. The abnormal protein was found throughout the brain, spinal cord and lymphoid tissues, with variable distribution in other organ systems. This finding confirms the potential susceptibility of this species to disease under natural conditions and the reliability of the current testing format for identifying the abnormal protein in the tissues routinely collected in surveillance programs. The widespread distribution of the abnormal protein in red deer indicates the potential for shedding of the agent into the environment. Technical Abstract: Chronic wasting disease CWD is the transmissible spongiform encephalopathy or prion disease of wild and farmed cervid ruminants, including Rocky Mountain elk (Cervus elaphus nelsoni), white tailed deer (Odocoileus virginianus), mule deer (Odocoileus hemionus), or moose (Alces alces). Reliable data on the susceptibility of other farmed cervid species, the distribution of the abnormal prion protein marker in brain and lymphoid tissues collected in surveillance programs, and the role of prion genotype are necessary for design of control programs for CWD in farmed cervids. In this study, red deer (Cervus elaphus elaphus) were exposed to the prion agent by oral administration of brain homogenates from infected Rocky Mountain elk. Antemortem testing was performed at 7 months post infection and the deer were euthanized when clinical disease was observed at approximately 18 months after infection. The abnormal prion protein was assayed by immunohistochemistry, enzyme linked immunosorbent assay and western blot. Abnormal prion protein was found in the spinal cord, brainstem, cerebellum, midbrain, thalamus, and cerebrum in all 4 infected red deer. Most of the lymph nodes throughout the body were positive for abnormal prion proteins. Abnromal prion protein was observed in some additional peripheral tissues in some but not all of the deer. In particular, most areas of the gastrointestinal tract were positive for abnormal prions, although the salivary glands were rarely positive. This study demonstrates the potential for oral transmission of chronic wasting disease to red deer and confirms the usefulness of the current testing methods for post mortem diagnosis of the disease in this species.

Oral transmission and early lymphoid tropism of chronic wasting disease PrPres in mule deer fawns (Odocoileus hemionus )

Christina J. Sigurdson1, Elizabeth S. Williams2, Michael W. Miller3, Terry R. Spraker1,4, Katherine I. O'Rourke5 and Edward A. Hoover1

Mule deer fawns (Odocoileus hemionus) were inoculated orally with a brain homogenate prepared from mule deer with naturally occurring chronic wasting disease (CWD), a prion-induced transmissible spongiform encephalopathy. Fawns were necropsied and examined for PrP res, the abnormal prion protein isoform, at 10, 42, 53, 77, 78 and 80 days post-inoculation (p.i.) using an immunohistochemistry assay modified to enhance sensitivity. PrPres was detected in alimentary-tract-associated lymphoid tissues (one or more of the following: retropharyngeal lymph node, tonsil, Peyer's patch and ileocaecal lymph node) as early as 42 days p.i. and in all fawns examined thereafter (53 to 80 days p.i.). No PrPres staining was detected in lymphoid tissue of three control fawns receiving a control brain inoculum, nor was PrPres detectable in neural tissue of any fawn. PrPres-specific staining was markedly enhanced by sequential tissue treatment with formic acid, proteinase K and hydrated autoclaving prior to immunohistochemical staining with monoclonal antibody F89/160.1.5. These results indicate that CWD PrP res can be detected in lymphoid tissues draining the alimentary tract within a few weeks after oral exposure to infectious prions and may reflect the initial pathway of CWD infection in deer. The rapid infection of deer fawns following exposure by the most plausible natural route is consistent with the efficient horizontal transmission of CWD in nature and enables accelerated studies of transmission and pathogenesis in the native species.


These results indicate that mule deer fawns develop detectable PrP res after oral exposure to an inoculum containing CWD prions. In the earliest post-exposure period, CWD PrPres was traced to the lymphoid tissues draining the oral and intestinal mucosa (i.e. the retropharyngeal lymph nodes, tonsil, ileal Peyer's patches and ileocaecal lymph nodes), which probably received the highest initial exposure to the inoculum. Hadlow et al. (1982) demonstrated scrapie agent in the tonsil, retropharyngeal and mesenteric lymph nodes, ileum and spleen in a 10-month-old naturally infected lamb by mouse bioassay. Eight of nine sheep had infectivity in the retropharyngeal lymph node. He concluded that the tissue distribution suggested primary infection via the gastrointestinal tract. The tissue distribution of PrPres in the early stages of infection in the fawns is strikingly similar to that seen in naturally infected sheep with scrapie. These findings support oral exposure as a natural route of CWD infection in deer and support oral inoculation as a reasonable exposure route for experimental studies of CWD.


see full text ;

Sunday, December 06, 2009

Detection of Sub-Clinical CWD Infection in Conventional Test-Negative Deer Long after Oral Exposure to Urine and Feces from CWD+ Deer

Wednesday, March 18, 2009

Detection of CWD Prions in Urine and Saliva of Deer by Transgenic Mouse Bioassay

Tuesday, June 16, 2009

Infectious Prions in Pre-Clinical Deer and Transmission of Chronic Wasting Disease Solely by Environmental Exposure

Wednesday, October 14, 2009

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area


Sunday, November 01, 2009

American crows (Corvus brachyrhynchos) and potential spreading of CWD through feces of digested infectious carcases

Wednesday, January 07, 2009

CWD to tighten taxidermy rules Hunters need to understand regulations



NOT only muscle, but now fat of CWD infected deer holds infectivity of the TSE (prion) agent. ...TSS

Monday, July 06, 2009

Prion infectivity in fat of deer with Chronic Wasting Disease

Friday, February 20, 2009

Both Sides of the Fence: A Strategic Review of Chronic Wasting Disease

Saturday, September 06, 2008

Chronic wasting disease in a Wisconsin white-tailed deer farm 79% INFECTION RATE

Contents: September 1 2008, Volume 20, Issue 5

snip...see full text ;

Tuesday, February 09, 2010

Chronic Wasting Disease: Surveillance Update North America: February 2010

*** In addition, we documented horizontal transmission of CWD from inoculated mice and to un-inoculated cohabitant cage-mates.

disturbing. ...TSS



Dr. Thornsberry: These prions are infective. That's the one thing that we've come to a common knowledge of here today, that's not being released by some of our cattle organizations. They are pushing the idea that a prion disease is an end-stage disease: an animal gets it, he dies, and that's the end of it. Being that these prions survive in the environment basically forever and there's no way to disinfect them, no way to destroy them, no way to get rid of them, the potential for BSE to be infective to any variety of animals does exist. We know that certain risk factors are much more inherent than others, but it is an infectious disease.

I have a small feed mill and there's no telling how many people have asked me if they can feed dog food to their show steers to increase the fat in their diet, not understanding that most dog food has some level of meat and bone meal in it.

Dr. Spraker: And people eat dog food and cat food.

Dr. Thornsberry: The association of dog food manufacturers has fought against a meat and bone meal ban and they don't even want to list it in their contents. They believe if it's listed, people will quit buying it. You have to fill out paperwork to buy fish food with meat and bone meal, but I could buy a whole truck load of dog food with meat and bone meal in it and feed it to my cattle.

It is illegal. There are some SRMs that are out there in this industry. Blood meal is one of my favorite concerns. We have a lot of big corporations that are using beef tallow in diets to increase the fat content in dairy rations. They're doing it as much as a pound per cow per day.

Dr. Detwiler: The thing that worries me is that those SRM’s are also in calf rations. The calves could have more susceptibility. I worry about the increased amount of blood going into calf rations.

Dr. Thornsberry: The concept of the prions making it through the system is very significant. Another issue we haven't discussed is the people taking the cleanings out of poultry barns and scattering them on their pastures for fertilizer. The prions don't ever go away, and the cattle eat the pasture down to the ground. How many prions are they being exposed to? There are a whole lot of issues there to deal with. Poultry manure can be composted and used as fuel and other things. It has alternative uses.

The swine industry has made better strides in telling people not to feed hog food to cattle, although I know it still goes on in my area. Fortunately, most of the swine finishing diets don't have any bone meal.

There are some things we need to do in our country to do a better job of surveillance. The veterinary industry needs to be proactive. I hope some of those SRMs are identified and the livestock producers are made aware of them and we get the information out: Don’t be feeding what's left over from your hog feed bin to your cattle.

Dr. Keller: Is there an economic analysis being done on the current situation in Canada, that could be used as an educational tool to encourage immediate consideration of other ways to utilize high risk product?

Dr. Detwiler: They are doing something on economic alternatives and what the costs would be.

Dr. Thornsberry: And there are a number of them. Any fat-soluble product has a number of possibilities and we've identified several of them today.

So here's the plan. These proceedings will be made available to the American Association of Bovine Practitioners, the Academy of Veterinary Consultants, to veterinary schools and whoever would like to have them. I will also try to translate and summarize the material into some sort of publication we can give to the livestock industry. They obviously don't want to know all about PRPC and all those things, but there is information in these presentations that they need to know.

You may want to add something that you didn’t say that you think might be pertinent. A lot of discussions like this have taken place, but nothing has been made available to the livestock industry—nothing on a practical level that a livestock producer can understand about the potential for CWD spreading, etc. They do not understand what BSE is. I hope, from this, we can give our producers a firm grasp of what the disease is and also let them know how they can participate in the process. And if we do that, we will have accomplished what I wanted to do with this program today.

Accomplished this day, Wednesday, December 11, 2003, Denver, Colorado


AUGUST 28, 2010

This new prionopathy in humans? the genetic makeup is IDENTICAL to the g-h-BSEalabama mad cow, the only _documented_ mad cow in the world to date like this, ......wait, it get's better. this new prionpathy is killing young and old humans, with LONG DURATION from onset of symptoms to death, and the symptoms are very similar to nvCJD victims, OH, and the plaques are very similar in some cases too, bbbut, it's not related to the g-h-BSEalabama cow, WAIT NOW, it gets even better, the new human prionpathy that they claim is a genetic TSE, has no relation to any gene mutation in that family. daaa, ya think it could be related to that mad cow with the same genetic make-up ??? there were literally tons and tons of banned mad cow protein in Alabama in commerce, and none of it transmitted to cows, and the cows to humans there from ??? r i g h t $$$ ...TSS

Rural and Regional Affairs and Transport References Committee The possible impacts and consequences for public health, trade and agriculture of the Government’s decision to relax import restrictions on beef

Final report June 2010 2.65

At its hearing on 14 May 2010, the committee heard evidence from Dr Alan Fahey who has recently submitted a thesis on the clinical neuropsychiatric, epidemiological and diagnostic features of Creutzfeldt-Jakob disease.48 Dr Fahey told the committee of his concerns regarding the lengthy incubation period for transmissible spongiform encephalopathies, the inadequacy of current tests and the limited nature of our current understanding of this group of diseases.49 2.66 Dr Fahey also told the committee that in the last two years a link has been established between forms of atypical CJD and atypical BSE. Dr Fahey said that: They now believe that those atypical BSEs overseas are in fact causing sporadic Creutzfeldt-Jakob disease. They were not sure if it was due to mad sheep disease or a different form. If you look in the textbooks it looks like this is just arising by itself. But in my research I have a summary of a document which states that there has never been any proof that sporadic Creutzfeldt-Jakob disease has arisen de novo—has arisen of itself. There is no proof of that. The recent research is that in fact it is due to atypical forms of mad cow disease which have been found across Europe, have been found in America and have been found in Asia. These atypical forms of mad cow disease typically have even longer incubation periods than the classical mad cow disease.50


In this study, we identified a novel mutation in the bovine prion protein gene (Prnp), called E211K, of a confirmed BSE positive cow from Alabama, United States of America. This mutation is identical to the E200K pathogenic mutation found in humans with a genetic form of CJD. This finding represents the first report of a confirmed case of BSE with a potential pathogenic mutation within the bovine Prnp gene. We hypothesize that the bovine Prnp E211K mutation most likely has caused BSE in "the approximately 10-year-old cow" carrying the E221K mutation.

Saturday, August 14, 2010

BSE Case Associated with Prion Protein Gene Mutation (g-h-BSEalabama) and VPSPr PRIONPATHY

(see mad cow feed in COMMERCE IN ALABAMA...TSS)

g-h-BSE-alabama E211K mad cows USA how many would that be annually ???

if our ciphering is correct (?), that would be about 35 g-h-BSE-alabama E211K mad cows going into the food chain a year.

an incidence of less than 1 in 2000.

let's see, that's 500 such per million.

or 50,000 cows per 100 million (US herd size).

even at less than 1 in a million, with 35 million slaughtered, that's 35 infected cows going into the food chain each year.

hmmm, friendly fire there from ???

Wednesday, July 28, 2010

re-Freedom of Information Act Project Number 3625-32000-086-05, Study of Atypical BSE UPDATE July 28, 2010

Tuesday, August 03, 2010

Variably protease-sensitive prionopathy: A new sporadic disease of the prion protein

Monday, August 9, 2010

Variably protease-sensitive prionopathy: A new sporadic disease of the prion protein or just more PRIONBALONEY ?

Thursday, August 12, 2010

Seven main threats for the future linked to prions


Wednesday, August 18, 2010

Incidence of CJD Deaths Reported by CJD-SS in Canada as of July 31, 2010

Monday, August 9, 2010

National Prion Disease Pathology Surveillance Center Cases Examined (July 31, 2010) (please watch and listen to the video and the scientist speaking about atypical BSE and sporadic CJD and listen to Professor Aguzzi)

" lieu of flowers donations be made to the Creutzfeldt-Jakob Disease Foundation" Beautiful picture of Christy at this link Christy ("Chris") Jean Worthington Her big, compassionate heart that was open to everyone, her bright, enthusiastic spirit, always ready for an adventure, her flair for fashion and design and turning any event into something special, her endless love for her family, her friends, and her life, her kind and beautiful soul. This is how we will remember Chris. Born May 24, 1948 in Los Angeles, she passed away peacefully at her Kerrville residence on August 19, 2010. She will be greatly missed by her parents, Robert and Irene Worthington of California, her fiancé Jim Leavell of Kerrville, sister Sue Worthington Webb of Nassau Bay, Texas, daughter Amber Bray, son-in-law Seth Bray, and granddaughter Kyla Bray of Austin, Texas, as well as her many friends--human and animal--including her three-legged cat, Annabelle. Funeral services will be at 1:00 p.m., Saturday, August 28th at Grimes Funeral Chapels with graveside service to follow at Garden of Memories. The family asks that in lieu of flowers donations be made to the Creutzfeldt-Jakob Disease Foundation or to Peterson Hospice. You are invited to send condolences at by selecting the "Send Condolences" link. Funeral arrangements are entrusted to Grimes Funeral Chapels of Kerrville. Published in Austin American-Statesman on August 25, 2010

Sunday, July 11, 2010

CJD 2 CASES McLennan County Texas population 230,213 both cases in their 40s


>>>Up until about 6 years ago, the pt worked at Tyson foods where she worked on the assembly line, slaughtering cattle and preparing them for packaging. She was exposed to brain and spinal cord matter when she would euthanize the cattle. <<<

Irma Linda Andablo CJD Victim, she died at 38 years old on February 6, 2010 in Mesquite Texas

Irma Linda Andablo CJD Victim, she died at 38 years old on February 6, 2010 in Mesquite Texas. She left 6 Kids and a Husband. The Purpose of this web is to give information in Spanish to the Hispanic community, and to all the community who want's information about this terrible disease.-

Physician Discharge Summary, Parkland Hospital, Dallas Texas

Admit Date: 12/29/2009 Discharge Date: 1/20/2010

Attending Provider: Greenberg, Benjamin Morris;

General Neurology Team: General Neurology Team

Linda was a Hispanic female with no past medical history presents with 14 months of incresing/progressive altered mental status, generalized weakness, inability to walk, loss of appetite, inability to speak, tremor and bowel/blader incontinence. She was, in her usual state of health up until February, 2009, when her husbans notes that she began forgetting things like names and short term memories. He also noticed mild/vague personality changes such as increased aggression. In March, she was involved in a hit and run MVA,although she was not injured. The police tracked her down and ticketed her. At that time, her son deployed to Iraq with the Army and her husband assumed her mentation changes were due to stress over these two events. Also in March, she began to have weakness in her legs, making it difficult to walk. Over the next few months, her mentation and personality changes worsened, getting to a point where she could no longer recognized her children. She was eating less and less. She was losing more weight. In the last 2-3 months, she reached the point where she could not walk without an assist, then 1 month ago, she stopped talking, only making grunting/aggressive sounds when anyone came near her. She also became both bowel and bladder incontinent, having to wear diapers. Her '"tremor'" and body jerks worsened and her hands assumed a sort of permanent grip position, leading her family to put tennis balls in her hands to protect her fingers. The husband says that they have lived in Nebraska for the past 21 years. They had seen a doctor there during the summer time who prescribed her Seroquel and Lexapro, Thinking these were sx of a mood disorder. However, the medications did not help and she continued to deteriorate clinically.

Up until about 6 years ago, the pt worked at Tyson foods where she worked on the assembly line, slaughtering cattle and preparing them for packaging. She was exposed to brain and spinal cord matter when she would euthanize the cattle. The husband says that he does not know any fellow workers with a similar illness. He also says that she did not have any preceeding illness or travel.

>>> Up until about 6 years ago, the pt worked at Tyson foods where she worked on the assembly line, slaughtering cattle and preparing them for packaging. She was exposed to brain and spinal cord matter when she would euthanize the cattle. <<<

Monday, March 29, 2010

Irma Linda Andablo CJD Victim, she died at 38 years old on February 6, 2010 in Mesquite Texas


Sunday, August 8, 2010

The Transcellular Spread of Cytosolic Amyloids, Prions, and Prionoids

Sunday, July 18, 2010

Alzheimer's Assocition International Conference on Alzheimer's Disease (updated diagnostic criteria) 2010 July 10 - 15 Honolulu, Hawaii

Friday, November 30, 2007


Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518

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