JOURNAL OF VIROLOGY, Feb. 2011, p. 1906–1908 Vol. 85, No. 4 0022-538X/11/$12.00 doi:10.1128/JVI.01872-10 Copyright © 2011, American Society for Microbiology. All Rights Reserved.
Strain-Specific Barriers against Bovine Prions in Hamsters
Simon Nicot and Thierry Baron* Agence Nationale de Se´curite´ Sanitaire, Lyon, France Received 3 September 2010/Accepted 17 November 2010
We investigated the susceptibilities of Syrian golden hamsters to transmissible spongiform encephalopathy agents from cattle. We report efficient transmission of the L-type atypical bovine spongiform encephalopathy (BSE) agent into hamsters. Importantly, hamsters were also susceptible to the transmissible mink encephalopathy agent from cattle, which has molecular features similar to those of the L-type BSE agent, as also shown in bovinized transgenic mice. In sharp contrast, hamsters could not be infected with classical or H-type BSE agents from cattle. However, previous adaptation of the classical BSE agent in wild-type mice led to efficient transmission. Thus, this study demonstrates the existence of distinct “strain barriers” upon the transmission of bovine prions in hamsters.
In recent years, bovine spongiform encephalopathy (BSE) cases with atypical molecular and/or neuropathological phenotypes have been reported in several European countries, in North America, and in Japan (12, 13, 17). Atypical BSE agents are currently classified into two types, L and H, according to the slightly lower (L) or higher (H) molecular mass of the proteaseresistant prion protein (PrPres) detected by Western blot analysis compared with the molecular mass of the classical (C-type) foodborne BSE agent. Given their low prevalence worldwide, such BSE cases have been assumed to represent sporadic forms of prion diseases.
Both of these atypical BSE agents have been experimentally challenged in different hosts, including cattle, sheep, monkeys, and wild-type or transgenic mice. Altogether, these experiments have demonstrated the infectious nature of such BSE cases and the existence of at least three distinct major prion strains in cattle. However, recent studies have indicated that the L-type BSE agent may acquire phenotypic features similar to those of the C-type BSE agent after inoculation into an ovine transgenic (tg338) mouse model or into inbred wild-type mice (4, 8). This supports the hypothesis that sporadic forms of BSE agents were possibly at the origin of the classical BSE epidemic in cattle.
In summary, Syrian golden hamsters developed prion disease after intracerebral challenge with both the L-type BSE agent and the TME agent passaged in cattle, whereas the classical and H-type BSE agents failed to transmit disease at first passage from bovine brains. PrPres detected in the brains of hamsters and bovinized transgenic mice inoculated with the L-type BSE agent or the TME agent passaged in cattle exhibited the same molecular characteristics (electrophoretic mobilities, 12B2 labeling, and glycoform ratios), consistent with our earlier observations of these two TSE sources transmitted in the TgOvPrP4 mouse line (1). In contrast, a clearly different PrPres pattern was observed in hamsters infected with the Ctype BSE agent from infected C57BL/6 mice, although similarly high levels of diglycosylated PrPres were identified in the three bovine TSE sources in hamsters. Altogether, these consistent observations strongly reinforce the hypothesis of a cross-species, food-borne transmission of the L-type BSE agent as the origin of TME.
Our findings also show that the absence of transmission of the classical or H-type BSE agent from cattle to hamsters is the result of a “strain barrier” rather than a “species barrier” between cattle and hamsters, which could be readily bypassed by the L-type BSE agent or the TME agent passaged in cattle in our study. The lack of transmissibility of the classical BSE agent from cattle to hamsters and its efficient transmission after a first passage in C57BL/6 wild-type mice are consistent with the results of previous studies (11, 20, 21). Hamsters were also susceptible to the SSBP/1 isolate from ovine transgenic TgOvPrP4 mice, consistent with the known susceptibility of hamsters to some scrapie sources (14). Interestingly, opposite outcomes of transmissions were observed between cattle and wild-type mice, with efficient primary transmissions of the classical and H-type BSE agents (2) but not of the L-type BSE agent or the TME agent passaged in cattle (8; S. Nicot and T. G. Baron, unpublished data), whereas the four bovine TSE agents transmitted readily to bovinized transgenic mice. Overall, our results well corroborate the notion that the majority of the so-called species barriers are actually strain barriers (10, 18) and suggest that the prion seeds of the L-type BSE agent and the TME agent passaged in cattle might be more conformationally compatible with the structure of the hamster prion protein.
It was recently proposed that interspecies transmission of prions could be tightly controlled by the local 2- 2 loop region of the PrP protein encompassing amino acid residues 165 to 175 (19). In particular, the homology at position 170 (S or N) was shown to be critical for prion transmission. Cattle, sheep, and mice are 170S animals, whereas Syrian hamsters are 170N animals. The transmission obtained in hamsters in our study thus illustrates that specific prion strains can overcome the codon 170 homology requirement (19). Conversely, the L-type BSE agent is not transmissible to wild-type mice (8; Nicot and Baron, unpublished data), which are susceptible to both the classical and the H-type BSE agents (2), although mice and cattle share the 170S amino acid. It could be speculated that particular conformations of the 2- 2 loop region may be associated with the TSE agent involved in L-type BSE or/and that differences in other regions of the prion protein sequence might be critical for the interspecies transmission of this recently identified form of BSE in cattle.
We thank J. M. Torres, Centro de Investigacio´n en Sanidad Animal, INIA, Madrid, Spain, for providing the BoPrP-Tg110 mouse line. We are grateful to Eric Morignat for statistical analyses of the data and to Emilie Antier, De´sire´ Challuau, and Latefa Chouaf-Lakhdar for the follow-up of animal experiments. S.N. was supported by a grant from Agence Nationale de Se´curite´ Sanitaire.
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
Phenotypic Similarity of Transmissible Mink Encephalopathy in Cattle and L-type Bovine Spongiform Encephalopathy in a Mouse Model
Thierry Baron,* Anna Bencsik,* Anne-Gaëlle Biacabe,* Eric Morignat,* andRichard A. Bessen†*Agence Française de Sécurité Sanitaire des Aliments–Lyon, Lyon, France; and†Montana State University, Bozeman, Montana, USA
Transmissible mink encepholapathy (TME) is a foodborne transmissible spongiform encephalopathy (TSE) of ranch-raised mink; infection with a ruminant TSE has been proposed as the cause, but the precise origin of TME is unknown. To compare the phenotypes of each TSE, bovine-passaged TME isolate and 3 distinct natural bovine spongiform encephalopathy (BSE) agents (typical BSE, H-type BSE, and L-type BSE) were inoculated into an ovine transgenic mouse line (TgOvPrP4). Transgenic mice were susceptible to infection with bovine-passaged TME, typical BSE, and L-type BSE but not to H-type BSE. Based on survival periods, brain lesions profiles, disease-associated prion protein brain distribution, and biochemical properties of protease-resistant prion protein, typical BSE had a distint phenotype in ovine transgenic mice compared to L-type BSE and bovine TME.The similar phenotypic properties of L-type BSE and bovine TME in TgOvPrP4 mice suggest that L-type BSE is a much more likely candidate for the origin of TME than is typical BSE.
These studies provide experimental evidence that the Stetsonville TME agent is distinct from typical BSE but has phenotypic similarities to L-type BSE in TgOvPrP4 mice. Our conclusion is that L-type BSE is a more likely candidate for a bovine source of TME infection than typical BSE. In the scenario that a ruminant TSE is the source for TME infection in mink, this would be a second example of transmission of a TSE from ruminants to non-ruminants under natural conditions or farming practices in addition to transmission of typical BSE to humans, domestic cats, and exotic zoo animals(37). The potential importance of this finding is relevant to L-type BSE, which based on experimental transmission into humanized PrP transgenic mice and macaques, suggests that L-type BSE is more pathogenic for humans than typical BSE (24,38).
Transmissible Mink Encephalopathy TME
In Confidence - Perceptions of unconventional slow virus diseasesof animals in the USA - APRIL-MAY 1989 - G A H Wells
Gerald Wells: Report of the Visit to USA, April-May 1989
The general opinion of those present was that BSE, as an overt disease phenomenon, _could exist in the USA, but if it did, it was very rare. The need for improved and specific surveillance methods to detect it as recognised...
It is clear that USDA have little information and _no_ regulatory responsibility for rendering plants in the US...
3. Prof. A. Robertson gave a brief account of BSE. The US approach was to accord it a _very low profile indeed_. Dr. A Thiermann showed the picture in the ''Independent'' with cattle being incinerated and thought this was a fanatical incident to be _avoided_ in the US _at all costs_...
please read this old full text document !
To be published in the Proceedings of the Fourth International Scientific Congress in Fur Animal Production. Toronto, Canada, August 21-28, 1988
Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle
R.F. Marsh* and G.R. Hartsough
•Department of Veterinary Science, University of Wisconsin-Madison, Madison, Wisconsin 53706; and ^Emba/Creat Lakes Ranch Service, Thiensville, Wisconsin 53092
Epidemiologic investigation of a new incidence of transmissible mink encephalopathy (TME) in Stetsonville, Wisconsin suggests that the disease may have resulted from feeding infected cattle to mink. This observation is supported by the transmission of a TME-like disease to experimentally inoculated cattle, and by the recent report of a new bovine spongiform encephalopathy in England.
Transmissible mink encephalopathy (TME) was first reported in 1965 by Hartsough and Burger who demonstrated that the disease was transmissible with a long incubation period, and that affected mink had a spongiform encephalopathy similar to that found inscrapie-affecied sheep (Hartsough and Burger, 1965; Burger and Hartsough, 1965). Because of the similarity between TME and scrapie, and the subsequent finding that the two transmissible agents were indistinguishable (Marsh and Hanson, 1969), it was concluded that TME most likely resulted from feeding mink scrapie-infecied sheep. The experimental transmission of sheep scrapie to mink (Hanson et al., 1971)confirmed the close association of TME and scrapie, but at the same time provided evidence that they may be different. Epidemiologic studies on previous incidences of TME indicated that the incubation periods in field cases were between six months and one year in length (Harxsough and Burger, 1965). Experimentally, scrapie could not be transmitted to mink in less than one year.To investigate the possibility that TME may be caused by a (particular strain of scrapie which might be highly pathogenic for mink, 21 different strains of the scrapie agent, including their sheep or goat sources, were inoculated into a total of 61 mink. Only one mink developed a progressive neurologic disease after an incubation period of 22 mon..s (Marsh and Hanson, 1979). These results indicated that TME was either caused by a strain of sheep scrapie not yet tested, or was due to exposure to a scrapie-like agent from an unidentified source.
OBSERVATIONS AND RESULTS
A New Incidence of TME. In April of 1985, a mink rancher in Stetsonville, Wisconsin reported that many of his mink were "acting funny", and some had died. At this time, we visited the farm and found that approximately 10% of all adult mink were showing typical signs of TME: insidious onset characterized by subtle behavioral changes, loss of normal habits of cleanliness, deposition of droppings throughout the pen rather than in a single area, hyperexcitability, difficulty in chewing and swallowing, and tails arched over their backs like squirrels. These signs were followed by progressive deterioration of neurologic function beginning with locomoior incoordination, long periods of somnolencein which the affected mink would stand motionless with its head in the corner of the cage, complete debilitation, and death. Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME. Since previous incidences of TME were associated with common or shared feeding practices, we obtained a careful history of feed ingredients used over the past 12-18months. The rancher was a "dead stock" feeder using mostly (>95%) downer or dead dairy cattle and a few horses. Sheep had never been fed.
Experimental Transmission. The clinical diagnosis of TME was confirmed by histopaihologic examination and by experimental transmission to mink after incubation periods of four months. To investigate the possible involvement of cattle in this disease cycle, two six-week old castrated Holstein bull calves were inoculated intracerebrally with a brain suspension from affected mink. Each developed a fatal spongiform encephalopathy after incubation periods of 18 and 19 months.
These findings suggest that TME may result from feeding mink infected cattle and we have alerted bovine practitioners that there may exist an as yet unrecognized scrapie-like disease of cattle in the United States (Marsh and Hartsough, 1986). A new bovine spongiform encephalopathy has recently been reported in England (Wells et al.,1987), and investigators are presently studying its transmissibility and possible relationship to scrapie. Because this new bovine disease in England is characterized by behavioral changes, hyperexcitability, and agressiveness, it is very likely it would be confused with rabies in the United Stales and not be diagnosed. Presently, brains from cattle in the United States which are suspected of rabies infection are only tested with anti-rabies virus antibody and are not examined histopathologically for lesions of spongiform encephalopathy. We are presently pursuing additional studies to further examine the possible involvement of cattle in the epidemiology of TME. One of these is the back passage of our experimental bovine encephalopathy to mink. Because (here are as yet no agent-specific proteins or nucleic acids identified for these transmissible neuropathogens, one means of distinguishing them is by animal passage and selection of the biotype which grows best in a particular host. This procedure has been used to separate hamster-adapted and mink-adapted TME agents (Marsh and Hanson, 1979). The intracerebral back passage of the experimental bovine agent resulted in incubations of only four months indicating no de-adaptation of the Stetsonville agent for mink after bovine passage. Mink fed infected bovine brain remain normal after six months. It will be essential to demonstrate oral transmission from bovine to mink if this proposed epidemiologic association is to be confirmed.
These studies were supported by the College of Agricultural and Life Sciences, University of Wisconsin-Madison and by a grant (85-CRCR-1-1812) from the United States Department of Agriculture. The authors also wish to acknowledge the help and encouragement of Robert Hanson who died during the course of these investigations.
Burger, D. and Hartsough, G.R. 1965. Encephalopathy of mink. II. Experimental andnatural transmission. J. Infec. Dis. 115:393-399.Hanson, R.P., Eckroade, R.3., Marsh, R.F., ZuRhein, C.M., Kanitz, C.L. and Gustatson,D.P. 1971. Susceptibility of mink to sheep scrapie. Science 172:859-861.Hansough, G.R. and Burger, D. 1965. Encephalopathy of mink. I. Epizoociologic andclinical observations. 3. Infec. Dis. 115:387-392.Marsh, R.F. and Hanson, R.P. 1969. Physical and chemical properties of thetransmissible mink encephalopathy agent. 3. ViroL 3:176-180.Marsh, R.F. and Hanson, R.P. 1979. On the origin of transmissible minkencephalopathy. In Hadlow, W.J. and Prusiner, S.P. (eds.) Slow transmissiblediseases of the nervous system. Vol. 1, Academic Press, New York, pp 451-460.Marsh, R.F. and Hartsough, G.R. 1986. Is there a scrapie-like disease incattle? Proceedings of the Seventh Annual Western Conference for Food AnimalVeterinary Medicine. University of Arizona, pp 20.Wells, G.A.H., Scott, A.C., Johnson, C.T., Cunning, R.F., Hancock, R.D.,Jeffrey, M., Dawson, M. and Bradley, R. 1987. A novel progressive spongiformencephalopathy in cattle. Vet. Rec. 121:419-420.
In Confidence - Perceptions of unconventional slow virus diseasesof animals in the USA - APRIL-MAY 1989 - G A H Wells
Given the large number of strains of scrapie and the possibility that BSE was one of them, it would be necessary to transmit every scrapie strain to cattle separately, to test the hypothesis properly. Such an experiment would be expensive. Secondly, as measures to control the epidemic took hold, the need for the experiment from the policy viewpoint was not considered so urgent. It was felt that the results would be mainly of academic interest.345 3.59 Nevertheless, from the first demonstration of transmissibility of BSE in 1988, the possibility of differences in the transmission properties of BSE and scrapie was clear. Scrapie was transmissible to hamsters, but by 1988 attempts to transmit BSE to hamsters had failed. Subsequent findings increased that possibility.
.57 The experiment which might have determined whether BSE and scrapie were caused by the same agent (ie, the feeding of natural scrapie to cattle) was never undertaken in the UK. It was, however, performed in the USA in 1979, when it was shown that cattle inoculated with the scrapie agent endemic in the flock of Suffolk sheep at the United States Department of Agriculture in Mission, Texas, developed a TSE quite unlike BSE. 32 The findings of the initial transmission, though not of the clinical or neurohistological examination, were communicated in October 1988 to Dr Watson, Director of the CVL, following a visit by Dr Wrathall, one of the project leaders in the Pathology Department of the CVL, to the United States Department of Agriculture. 33 The results were not published at this point, since the attempted transmission to mice from the experimental cow brain had been inconclusive. The results of the clinical and histological differences between scrapie-affected sheep and cattle were published in 1995. Similar studies in which cattle were inoculated intracerebrally with scrapie inocula derived from a number of scrapie-affected sheep of different breeds and from different States, were carried out at the US National Animal Disease Centre. 34 The results, published in 1994, showed that this source of scrapie agent, though pathogenic for cattle, did not produce the same clinical signs of brain lesions characteristic of BSE.
32 Clark, W., Hourrigan, J. and Hadlow, W. (1995) Encephalopathy in Cattle Experimentally Infected with the Scrapie Agent, American Journal of Veterinary Research, 56, 606-12
Wednesday, July 28, 2010
Atypical prion proteins and IBNC in cattle DEFRA project code SE1796 FOIA Final report
Saturday, February 28, 2009
NEW RESULTS ON IDIOPATHIC BRAINSTEM NEURONAL CHROMATOLYSIS "All of the 15 cattle tested showed that the brains had abnormally accumulated PrP" 2009
Subject: TME hyper/drowsy, INTER-SPECIES TRANSMISSION CWD and strain properties Date: October 22, 2007 at 12:48 pm PST
Completely Edited Version
TME hyper/drowsy, INTER-SPECIES TRANSMISSION CWD and strain properties
page 19 of 62. ...tss
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, what ever 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 becareful 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'tknow. 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 hostPRPSC? 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.
Accomplished this day, Wednesday, December 11, 2003, Denver, Colorado
The roundtable presentations and discussions were recorded. A transcript will be made available to the Academy of Veterinary Consultants, the American Association of Bovine Practitioners, and the Colleges of Veterinary Medicine throughout the United States and Canada. A condensed version translated for the livestock industry will be made available to educate livestock producers about prion related diseases.
SEE FULL TEXT TME
Aspects of the Cerebellar Neuropathology in Nor98
Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute,
Norway Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
NOR98 SHOWS MOLECULAR FEATURES REMINISCENT OF GSS
R. Nonno1, E. Esposito1, G. Vaccari1, E. Bandino2, M. Conte1, B. Chiappini1, S. Marcon1, M. Di Bari1, S.L. Benestad3, U. Agrimi1 1 Istituto Superiore di Sanità, Department of Food Safety and Veterinary Public Health, Rome, Italy (email@example.com); 2 Istituto Zooprofilattico della Sardegna, Sassari, Italy; 3 National Veterinary Institute, Department of Pathology, Oslo, Norway
Molecular variants of PrPSc are being increasingly investigated in sheep scrapie and are generally referred to as "atypical" scrapie, as opposed to "classical scrapie". Among the atypical group, Nor98 seems to be the best identified. We studied the molecular properties of Italian and Norwegian Nor98 samples by WB analysis of brain homogenates, either untreated, digested with different concentrations of proteinase K, or subjected to enzymatic deglycosylation. The identity of PrP fragments was inferred by means of antibodies spanning the full PrP sequence. We found that undigested brain homogenates contain a Nor98-specific PrP fragment migrating at 11 kDa (PrP11), truncated at both the C-terminus and the N-terminus, and not N-glycosylated. After mild PK digestion, Nor98 displayed full-length PrP (FL-PrP) and N-glycosylated C-terminal fragments (CTF), along with increased levels of PrP11. Proteinase K digestion curves (0,006-6,4 mg/ml) showed that FL-PrP and CTF are mainly digested above 0,01 mg/ml, while PrP11 is not entirely digested even at the highest concentrations, similarly to PrP27-30 associated with classical scrapie. Above 0,2 mg/ml PK, most Nor98 samples showed only PrP11 and a fragment of 17 kDa with the same properties of PrP11, that was tentatively identified as a dimer of PrP11. Detergent solubility studies showed that PrP11 is insoluble in 2% sodium laurylsorcosine and is mainly produced from detergentsoluble, full-length PrPSc. Furthermore, among Italian scrapie isolates, we found that a sample with molecular and pathological properties consistent with Nor98 showed plaque-like deposits of PrPSc in the thalamus when the brain was analysed by PrPSc immunohistochemistry. Taken together, our results show that the distinctive pathological feature of Nor98 is a PrP fragment spanning amino acids ~ 90-155. This fragment is produced by successive N-terminal and C-terminal cleavages from a full-length and largely detergent-soluble PrPSc, is produced in vivo and is extremely resistant to PK digestion.
*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.
A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes
Annick Le Dur*,?, Vincent Béringue*,?, Olivier Andréoletti?, Fabienne Reine*, Thanh Lan Laï*, Thierry Baron§, Bjørn Bratberg¶, Jean-Luc Vilotte?, Pierre Sarradin**, Sylvie L. Benestad¶, and Hubert Laude*,?? +Author Affiliations
*Virologie Immunologie Moléculaires and ?Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; ?Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; §Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway
***Edited by Stanley B. Prusiner, University of California, San Francisco, CA (received for review March 21, 2005)
Abstract Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrPSc detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrPSc molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice.
*** These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.
Monday, December 1, 2008
When Atypical Scrapie cross species barriers
Andreoletti O., Herva M. H., Cassard H., Espinosa J. C., Lacroux C., Simon S., Padilla D., Benestad S. L., Lantier F., Schelcher F., Grassi J., Torres, J. M., UMR INRA ENVT 1225, Ecole Nationale Veterinaire de Toulouse.France; ICISA-INlA, Madrid, Spain; CEA, IBiTec-5, DSV, CEA/Saclay, Gif sur Yvette cedex, France; National Veterinary Institute, Postboks 750 Sentrum, 0106 Oslo, Norway, INRA IASP, Centre INRA de Tours, 3738O Nouzilly, France.
Atypical scrapie is a TSE occurring in small ruminants and harbouring peculiar clinical, epidemiological and biochemical properties. Currently this form of disease is identified in a large number of countries. In this study we report the transmission of an atypical scrapie isolate through different species barriers as modeled by transgenic mice (Tg) expressing different species PRP sequence.
The donor isolate was collected in 1995 in a French commercial sheep flock. inoculation into AHQ/AHQ sheep induced a disease which had all neuro-pathological and biochemical characteristics of atypical scrapie. Transmitted into Transgenic mice expressing either ovine or PrPc, the isolate retained all the described characteristics of atypical scrapie.
Surprisingly the TSE agent characteristics were dramatically different v/hen passaged into Tg bovine mice. The recovered TSE agent had biological and biochemical characteristics similar to those of atypical BSE L in the same mouse model. Moreover, whereas no other TSE agent than BSE were shown to transmit into Tg porcine mice, atypical scrapie was able to develop into this model, albeit with low attack rate on first passage.
Furthermore, after adaptation in the porcine mouse model this prion showed similar biological and biochemical characteristics than BSE adapted to this porcine mouse model. Altogether these data indicate.
(i) the unsuspected potential abilities of atypical scrapie to cross species barriers
(ii) the possible capacity of this agent to acquire new characteristics when crossing species barrier
These findings raise some interrogation on the concept of TSE strain and on the origin of the diversity of the TSE agents and could have consequences on field TSE control measures.
Sunday, October 3, 2010
Scrapie, Nor-98 atypical Scrapie, and BSE in sheep and goats North America, who's looking ?
Sunday, December 12, 2010
EFSA reviews BSE/TSE infectivity in small ruminant tissues News Story 2 December 2010
One of these isolates (TR316211) behaved like the CH1641 isolate, with PrPres features in mice similar to those in the sheep brain. From two other isolates (O100 and O104), two distinct PrPres phenotypes were identified in mouse brains, with either high (h-type) or low (l-type) apparent molecular masses of unglycosylated PrPres, the latter being similar to that observed with CH1641, TR316211, or BSE. Both phenotypes could be found in variable proportions in the brains of the individual mice. In contrast with BSE, l-type PrPres from "CH1641-like" isolates showed lower levels of diglycosylated PrPres. From one of these cases (O104), a second passage in mice was performed for two mice with distinct PrPres profiles. This showed a partial selection of the l-type phenotype in mice infected with a mouse brain with predominant l-type PrPres, and it was accompanied by a significant increase in the proportions of the diglycosylated band. These results are discussed in relation to the diversity of scrapie and BSE strains.
In the US, scrapie is reported primarily in sheep homozygous for 136A/171Q (AAQQ) and the disease phenotype is similar to that seen with experimental strain CH1641.
4.2.9 A further hypothesis to explain the occurrence of BSE is the emergence or selection of a strain or strains of the scrapie agent pathogenic for cattle. Mutations of the scrapie agent. which can occur after a single passage in mice. have been well documented (9). This phenomenon cannot be dismissed for BSE. but given the form of the epidemic and the geographically widespread occurrence of BSE, such a hypothesis" would require the emergence of a mutant scrapie strain simultaneously in a large . number of sheep flocks, or cattle. throughout the country. Also. if it resulted "from a localised chance transmission of the scrapie strain from sheep to cattle giving rise , . to a mutant. a different pattern of disease would have been expected: its range would '. have increased with time. Thus the evidence from Britain is against the disease being due to a new strain of the agent, but we note that in the United States from 1984 to 1988 outbreaks of scrapie in sheep flocks are reported to have Increased markedly. now being nearly 3 times as high as during any previous period (18).
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. ...
SNIP...SEE FULL TEXT ;
Thursday, December 23, 2010
Molecular Typing of Protease-Resistant Prion Protein in Transmissible Spongiform Encephalopathies of Small Ruminants, France, 2002–2009 Volume 17, Number 1–January 2011
Sunday, April 18, 2010
SCRAPIE AND ATYPICAL SCRAPIE TRANSMISSION STUDIES A REVIEW 2010
UPDATED DATA ON 2ND CWD STRAIN
Wednesday, September 08, 2010
CWD PRION CONGRESS SEPTEMBER 8-11 2010
The TSE road map defining the evolution of European policy for protection against prion diseases is based on a certain numbers of hypotheses some of which may turn out to be erroneous. In particular, a form of BSE (called atypical Bovine Spongiform Encephalopathy), recently identified by systematic testing in aged cattle without clinical signs, may be the origin of classical BSE and thus potentially constitute a reservoir, which may be impossible to eradicate if a sporadic origin is confirmed.
*** Also, a link is suspected between atypical BSE and some apparently sporadic cases of Creutzfeldt-Jakob disease in humans. These atypical BSE cases constitute an unforeseen first threat that could sharply modify the European approach to prion diseases.
Wednesday, January 19, 2011
EFSA and ECDC review scientific evidence on possible links between TSEs in animals and humans Webnachricht 19 Januar 2011
Wednesday, January 19, 2011
EFSA BIOHAZ Scientific Opinion on the revision of the quantitative risk assessment (QRA) of the BSE risk posed by processed animal proteins (PAPs)
EFSA Journal 2011;9(1):1947
Monday, January 17, 2011
MAD COW Update on Feed Enforcement Activities to Limit the Spread of BSE January 13, 2011
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.
Wednesday, March 31, 2010
Atypical BSE in Cattle
The EMBO Journal (2002) 21, 6358 - 6366 doi:10.1093/emboj/cdf653
BSE prions propagate as either variant CJD-like or sporadic CJD-like prion strains in transgenic mice expressing human prion protein
Emmanuel A. Asante1, Jacqueline M. Linehan1, Melanie Desbruslais1, Susan Joiner1, Ian Gowland1, Andrew L. Wood1, Julie Welch1, Andrew F. Hill1, Sarah E. Lloyd1, Jonathan D.F. Wadsworth1 and John Collinge1
1.MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College, Queen Square, London WC1N 3BG, UK Correspondence to:
John Collinge, E-mail: firstname.lastname@example.org
Received 1 August 2002; Accepted 17 October 2002; Revised 24 September 2002
Variant Creutzfeldt–Jakob disease (vCJD) has been recognized to date only in individuals homozygous for methionine at PRNP codon 129. Here we show that transgenic mice expressing human PrP methionine 129, inoculated with either bovine spongiform encephalopathy (BSE) or variant CJD prions, may develop the neuropathological and molecular phenotype of vCJD, consistent with these diseases being caused by the same prion strain. Surprisingly, however, BSE transmission to these transgenic mice, in addition to producing a vCJD-like phenotype, can also result in a distinct molecular phenotype that is indistinguishable from that of sporadic CJD with PrPSc type 2. These data suggest that more than one BSE-derived prion strain might infect humans; it is therefore possible that some patients with a phenotype consistent with sporadic CJD may have a disease arising from BSE exposure.
Keywords:BSE, Creutzfeldt–Jakob disease, prion, transgenic
BSE prions propagate as either variant CJD-like or sporadic CJD-like prion strains in transgenic mice expressing human prion protein
Emmanuel A. Asante, Jacqueline M. Linehan, Melanie Desbruslais, Susan Joiner, Ian Gowland, Andrew L. Wood, Julie Welch, Andrew F. Hill, Sarah E. Lloyd, Jonathan D.F. Wadsworth, and John Collinge1 MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College, Queen Square, London WC1N 3BG, UK 1Corresponding author e-mail: email@example.comReceived August 1, 2002; Revised September 24, 2002; Accepted October 17, 2002.
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 ***
Response to Public Comments on the Harvard Risk Assessment of BSE USA
RESPONSE TO COMMENTS FROM TERRY S. SINGELTARY SR. Comment #1: SINCE the first Harvard BSE Risk Assessment was so flawed and fraught ...
LET'S take a closer look at this new prionpathy or prionopathy, and then let's look at the g-h-BSEalabama mad cow.
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 $$$
ALABAMA MAD COW g-h-BSEalabama
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)
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.
2009 UPDATE ON ALABAMA AND TEXAS MAD COWS 2005 and 2006
Wednesday, December 29, 2010
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY PRION END OF YEAR REPORT DECEMBER 29, 2010
"According to the World Health Organisation, the future public health threat of vCJD in the UK and Europe and potentially the rest of the world is of concern and currently unquantifiable. However, the possibility of a significant and geographically diverse vCJD epidemic occurring over the next few decades cannot be dismissed.
The key word here is diverse. What does diverse mean?
If USA scrapie transmitted to USA bovine does not produce pathology as the UK c-BSE, then why would CJD from there look like UK vCJD?"
SEE FULL TEXT ;
Tuesday, January 18, 2011
Agent strain variation in human prion disease: insights from a molecular and pathological review of the National Institutes of Health series of experimentally transmitted disease
PLEASE NOTE REFERENCE LINES 5. AND 6. AT BOTTOM ;
Monday, August 9, 2010
National Prion Disease Pathology Surveillance Center Cases Examined (July 31, 2010) Year Total Referrals2 Prion Disease Sporadic Familial Iatrogenic vCJD
1996 & earlier 51 33 28 5 0 0
1997 114 68 59 9 0 0
1998 88 52 44 7 1 0
1999 120 72 64 8 0 0
2000 146 103 89 14 0 0
2001 209 119 109 10 0 0
2002 248 149 125 22 2 0
2003 274 176 137 39 0 0
2004 325 186 164 21 0 1(3)
2005 344 194 157 36 1 0
2006 383 197 166 29 0 2(4)
2007 377 214 187 27 0 0
2008 394 231 204 25 0 0
2009 425 259 216 43 0 0
2010 204 124 85 20 0 0
TOTAL 3702(5) 2177(6) 1834 315 4 3
1 Listed based on the year of death or, if not available, on year of referral;
2 Cases with suspected prion disease for which brain tissue and/or blood (in familial cases) were submitted;
3 Disease acquired in the United Kingdom;
4 Disease was acquired in the United Kingdom in one case and in Saudi Arabia in the other case;
5 Includes 16 cases in which the diagnosis is pending, and 18 inconclusive cases;
6 Includes 21 (19 from 2010) cases with type determination pending in which the diagnosis of vCJD has been excluded.
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)
Manuscript Draft Manuscript Number: Title: HUMAN and ANIMAL TSE Classifications i.e. mad cow disease and the UKBSEnvCJD only theory Article Type: Personal View Corresponding Author: Mr. Terry S. Singeltary, Corresponding Author's Institution: na First Author: Terry S Singeltary, none Order of Authors: Terry S Singeltary, none; Terry S. Singeltary
Abstract: TSEs have been rampant in the USA for decades in many species, and they all have been rendered and fed back to animals for human/animal consumption. 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 2007.
Saturday, June 13, 2009
Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States 2003 revisited 2009
Saturday, January 2, 2010
Human Prion Diseases in the United States January 1, 2010 ***FINAL***
my comments to PLosone here ;
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
Bacliff, TX, USA
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.
12 years independent research of available data
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.
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.
Tuesday, December 14, 2010
Infection control of CJD, vCJD and other human prion diseases in healthcare and community settings part 4, Annex A1, Annex J, UPDATE DECEMBER 2010
HOW many of you recieved a written CJD Questionnaire asking real questions pertaining to route and source (and there are many here in North America) ?
IS every case getting a cjd questionnaire asking real questions ???
Friday, November 30, 2007
CJD QUESTIONNAIRE USA CWRU AND CJD FOUNDATION USA PRION UNIT