Atypical Bovine Spongiform Encephalopathy, Should we be Worried? Hong Kong Government
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Food Safety Focus (237th Issue, Apr 2026) – Article 2
Atypical Bovine Spongiform Encephalopathy – Should we be Worried?
Reported by Dr. Ivan CHONG and Dr. Raymond CHEUNG, Veterinary Officers, Veterinary Public Health Section, Centre for Food Safety
Bovine Spongiform Encephalopathy (BSE), widely known as "mad cow disease", triggered a global food safety crisis in the 1990s due to its link to variant Creutzfeldt-Jakob Disease (vCJD) in humans. While decades of coordinated international efforts have led to a remarkable decline in classical BSE cases worldwide, its lesser-known relative, atypical BSE, continues to surface in isolated cases. This article examines the key differences between classical and atypical BSE. By understanding the features of atypical BSE and the available epidemiological evidence, we can assess whether this lesser-known variant warrants public health concern.
Origins and Transmission
Classical BSE emerged in the 1980s as a consequence of recycling ruminant proteins in cattle feed. The practice of supplementing feed with rendered tissues from infected cattle allowed prions (misfolded proteins that cause BSE) to amplify through herds, creating an exponential transmission cycle that affected millions of animals and led to human vCJD cases through consumption of contaminated beef products.
Atypical BSE, first identified in 2003 through enhanced surveillance, presents a different picture. It occurs spontaneously in older cattle, typically aged eight years or more, with no connection to contaminated feed. Although the precise pathogenesis is not yet fully understood, scientists believe that age-related protein misfolding or genetic factors may trigger the condition. Unlike classical BSE, there is to date no evidence of natural field transmission of atypical BSE between animals or to humans, making each case an isolated event.
Food Safety Implications
The food safety risks of classical and atypical BSE differ significantly. Classical BSE posed clear risks, with indications that vCJD could be acquired through the consumption of contaminated beef products. Control measures such as bans on ruminant proteins in cattle feed and removal of tissues with greatest infectivity (e.g. brain and spinal cord) from the food chain were implemented in affected countries to eliminate these risks. According to the World Organisation for Animal Health (WOAH), the incidence of classical BSE has fallen dramatically and is now negligible, with nearly zero cases per million bovines.
Atypical BSE, on the other hand, has not been linked to vCJD and occurs spontaneously in older cattle at a negligible rate; which, when combined with existing food safety measures such as ante-mortem inspection and health certification systems, makes human exposure highly unlikely. In addition, the same protections that brought classical BSE under control (e.g. feed bans and removal of tissues with greatest infectivity) can also prevent atypical BSE prions from entering the human food chain. After nearly two decades of global monitoring, no human cases have been linked to atypical BSE, though researchers continue to study its theoretical risks
Figure: Map of BSE Official Status by WOAH (As of June 2025)
Regulatory Response
WOAH mandates distinct responses to classical and atypical BSE, reflecting their differing risks to animal and human health. Classical BSE, as a WOAH-listed disease, triggers international reporting obligations and strict containment measures. When a classical BSE case is detected, the affected country must notify WOAH, conduct trace-back investigations, impose quarantines on exposed herds and review feed ban compliance. WOAH officially recognises a country’s BSE risk status, from the lowest risk level “negligible”, to “controlled” and the rest as “undetermined”, after evaluating its history with classical BSE, implementation of the feed ban and disease surveillance, with trade guidelines aligned to each risk status. In Hong Kong, beef should be imported from countries or areas that meet public health requirements corresponding to the WOAH official BSE risk status.
In contrast, atypical BSE has been delisted by WOAH as a notifiable disease since 2023, due to its rare and sporadic nature and the finding that it has no significant impact on animal or public health. Detection of an atypical BSE case does not require emergency reporting or trade disruptions. However, as a precautionary measure, WOAH requires members to provide evidence that any bovines detected with atypical BSE have been completely destroyed or disposed of to ensure they do not enter the feed or food chain. As atypical BSE occurs spontaneously at a low rate in all cattle populations, its detection would not impact a country’s WOAH risk status.
Conclusion
Unlike classical BSE, atypical BSE is not known to spread naturally between animals or through feed, occurring only as rare, isolated cases in older cattle. The same protective measures developed in response to classical BSE provide robust protection against this sporadic form of the disease. WOAH’s decision to delist atypical BSE further underscores that it has no significant impact on public health. Decades of global surveillance have confirmed these safeguards work, with no human cases linked to atypical BSE.
Last revision date: 22 Apr 2026
From: TERRY SINGELTARY <flounder9@verizon.net>
Date: April 22, 2026 at 4:06:55 PM CDT
To: ivan_fk_chong@afcd.gov.hk, rtcheung@hkucc.hku.hk
Cc: dfehoffice@fehd.gov.hk, lawkw@fehd.gov.hk, arseneyiu@fehd.gov.hk, cfsoffice@fehd.gov.hk
Subject: Atypical Bovine Spongiform Encephalopathy, Should we be Worried? Hong Kong Government
“In contrast, atypical BSE has been delisted by WOAH as a notifiable disease since 2023, due to its rare and sporadic nature and the finding that it has no significant impact on animal or public health. Detection of an atypical BSE case does not require emergency reporting or trade disruptions.”
I don’t know if the Honorable Dr. Ivan CHONG and Dr. Raymond CHEUNG, Veterinary Officers, Veterinary Public Health Section, Centre for Food Safety, are just not up to date with recent science of the atypical strains of Transmissible Spongiform Encephalopathy TSE atypical BSE and atypical Scrapie, or they are simply trying to go along with the same old science from earlier BSE days 40 years or so ago, and science there from, that most other countries seem to rubber stamp, but regardless, this report on atypical Bovine Spongiform Encephalopathy BSE, from Hong Kong Government, Center For Food Safety, Food Safety Focus (237th Issue, Apr 2026) – Article 2, i would kindly like to bring urgent attention to updated science about atypical BSE and atypical Scrapie, that the WHOA WHO et al seem very concerned with, but failed to act… kindest regards, terry
“In contrast, atypical BSE has been delisted by WOAH as a notifiable disease since 2023, due to its rare and sporadic nature and the finding that it has no significant impact on animal or public health. Detection of an atypical BSE case does not require emergency reporting or trade disruptions.”
“According to the World Organisation for Animal Health (WOAH), Terrestrial Manual 2021, atypical BSE, caused by H- and L-type BSE agents, is rare and is believed to occur spontaneously in all bovine populations at a very low rate and has only been identified in older cattle.”
My Concerns with atypical BSE as Follows;
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
https://www.nature.com/articles/srep11573
https://www.ars.usda.gov/research/publications/publication/?seqNo115=361032
Atypical BSE in cattle
THE recent diagnosis of two atypical bovine spongiform encephalopathy (BSE) cases in Great Britain (March 2023 in Cornwall and December 2024 in Dumfries and Galloway) and one in the Republic of Ireland (in November 2023) warrants a reminder about this notifiable disease.
Since 2005, a total of 17 cases have been detected in Great Britain.1 Unlike classical BSE, which resulted in over 180,000 cases in Great Britain and was predominantly associated with the consumption of feed contaminated with the BSE agent, and where the last case was confirmed in Ayrshire in May 2024, atypical BSE is believed to be a spontaneous disease in cattle found in approximately one in 1,000,000 tested cattle based on French data,2 similar to the sporadic Creutzfeldt- Jakob disease in people. There is currently no evidence that atypical BSE causes a disease in people, although it can be transmitted experimentally to other species by intracerebral inoculation, including primates.3–5 The World Organisation for Animal Health does not include atypical BSE in its geographical BSE risk status assessment.
Despite differences in terms of epidemiological, molecular and biological phenotype compared with classical BSE, atypical BSE is currently treated as if it were classical BSE in accordance with EU and UK legislation: once a case is identified, all cohort animals born and reared with the affected animal during the first 12 months of its life, and all offspring born within 24 months of its clinical onset, are culled and tested for BSE, which does seem to be at odds with the hypothesis that it is a spontaneous disease. This is more a precautionary measure to maintain confidence in the beef trade and protect consumers while more knowledge about this disease is obtained.
Almost all current knowledge on atypical BSE is based on experimental infection because this spontaneous
VET RECORD | 29 March–12 April 2025
disease has generally only been found in aged downer cows, which is difficult to replicate experimentally in the host species. Intracerebral inoculation of brain tissue from an affected cow causes disease in cattle in less than two years, unlike the natural disease that usually occurs in animals over eight years of age.
The vast majority of cases have been identified by active monitoring of fallen stock or emergency slaughter of cattle, where only the brain sample of various stages of autolysis is generally available. Little is known of where the atypical BSE agent can be found in natural disease, other than in the brain, because all the cases confirmed have been identified after death through active surveillance, by which time most peripheral tissue has been disposed of. Limited material from a single case of a naturally affected cow was tested in Italy by mouse bioassay, which found infectivity in muscle.6 In experimental disease generated by intracerebral inoculation of cattle, infectivity can be detected in the brain and spinal cord, ganglia, peripheral nerves and skeletal muscles, similar to classical BSE, but not in peripheral lymphoid tissue.6–8
Early reporting of clinical suspects is needed so that the live animal or the whole carcase can be delivered to an APHA regional laboratory for tissue sampling. This is made more difficult due to the subtlety of clinical signs based on experimental disease. Clinical cases may not be as over- reactive or nervous as classical BSE cases; some may, in fact, be dull, but what most cases have in common is that they have difficulty getting up and eventually end up as downer cows, and only the clinical history may reveal some prior behavioural or locomotor changes. High creatinine kinase serum levels and nibbling in response to scratching the tail head or back were some features in experimental disease,8, 9 but it is not known whether this is also seen in natural disease.
In general, BSE should be considered as a differential diagnosis in all downer cows that do not respond to treatment, where the blood results do not support the presence of a metabolic disease and where the cause cannot be determined with confidence.
Since BSE is a notifiable disease, suspected cases of BSE in Great Britain must be reported to the local APHA office.
Changes are imminent in the reporting of fallen stock cattle, which will require the owner to state whether the animal displayed signs of changes in behaviour, sensation or locomotion before death, in addition to the likely cause of death or disease. This is to obtain a better profile of the clinical history, if cattle are retrospectively diagnosed as BSE cases, which has happened in all BSE cases confirmed since 2010: none has been reported as a clinical suspect.
“BSE should be considered as a differential diagnosis in all downer cows that do not respond to treatment”
Timm Konold, TSE lead scientist
Brenda Rajanayagam, workgroup leader for the data systems group
APHA Weybridge, New Haw, Addlestone, Surrey KT15 3NB email: timm.konold@apha.gov.uk
Keith Meldrum, former chief veterinary officer The Orchard, Swaynes Lane, Guildford, Surrey GU1 2XX
References
1 APHA. Cattle: TSE surveillance statistics. Overview of Great Britain statistics. 2025. https://bit.ly/4ho5Nds (accessed 19 March 2025)
Atypical BSE In Cattle
https://bvajournals.onlinelibrary.wiley.com/doi/abs/10.1002/vetr.5400?campaign=woletoc
Title: Transmission of atypical BSE: a possible origin of Classical BSE in cattle
Authors: Sandor Dudas1, Samuel James Sharpe1, Kristina Santiago-Mateo1, Stefanie Czub1, Waqas Tahir1,2, *
Affiliation: 1National and WOAH reference Laboratory for Bovine Spongiform Encephalopathy, Canadian Food inspection Agency, Lethbridge Laboratory, Lethbridge, Canada. 2Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
*Corresponding and Presenting Author: waqas.tahir@inspection.gc.ca
Background: Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disease of cattle and is categorized into classical and atypical forms. Classical BSE (CBSE) is linked to the consumption of BSE contaminated feed whereas atypical BSE is considered to be spontaneous in origin. The potential for oral transmission of atypical BSE is yet to be clearly defined.
Aims: To assess the oral transmissibility of atypical BSE (H and L type) in cattle. Should transmission be successful, determine the biochemical characteristics and distribution of PrPSc in the challenge cattle.
Material and Methods: For oral transmission, calves were fed with 100 g of either H (n=3) or L BSE (n=3) positive brain material. Two years post challenge, 1 calf from each of the H and L BSE challenge groups exhibited behavioural signs and were euthanized. Various brain regions of both animals were tested by traditional and novel prion detection methods with inconclusive results. To detect infectivity, brain homogenates from these oral challenge animals (P1) were injected intra-cranially (IC) into steer calves. Upon clinical signs of BSE, 3/4 of IC challenged steer calves were euthanized and tested for PrPSc with ELISA, immunohistochemistry and immunoblot.
Results: After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE.
Conclusion: These results demonstrate the oral transmission potential of atypical BSE in cattle. Surprisingly, regardless of which atypical type of BSE was used for P1 oral challenge, PrPSc in the P2 animals acquired biochemical characteristics similar to that of PrPSc in C-BSE, suggesting atypical BSE as a possible origin of C-BSE in UK.
Presentation Type: Oral Presentation
Funded by: CFIA, Health Canada, Alberta Livestock and Meat Agency, Alberta Prion Research Institute
Grant Number: ALMA/APRI: 201400006, HC 414250
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
https://www.nature.com/articles/srep11573
https://www.ars.usda.gov/research/publications/publication/?seqNo115=361032
Atypical BSE in cattle
THE recent diagnosis of two atypical bovine spongiform encephalopathy (BSE) cases in Great Britain (March 2023 in Cornwall and December 2024 in Dumfries and Galloway) and one in the Republic of Ireland (in November 2023) warrants a reminder about this notifiable disease.
Since 2005, a total of 17 cases have been detected in Great Britain.1 Unlike classical BSE, which resulted in over 180,000 cases in Great Britain and was predominantly associated with the consumption of feed contaminated with the BSE agent, and where the last case was confirmed in Ayrshire in May 2024, atypical BSE is believed to be a spontaneous disease in cattle found in approximately one in 1,000,000 tested cattle based on French data,2 similar to the sporadic Creutzfeldt- Jakob disease in people. There is currently no evidence that atypical BSE causes a disease in people, although it can be transmitted experimentally to other species by intracerebral inoculation, including primates.3–5 The World Organisation for Animal Health does not include atypical BSE in its geographical BSE risk status assessment.
Despite differences in terms of epidemiological, molecular and biological phenotype compared with classical BSE, atypical BSE is currently treated as if it were classical BSE in accordance with EU and UK legislation: once a case is identified, all cohort animals born and reared with the affected animal during the first 12 months of its life, and all offspring born within 24 months of its clinical onset, are culled and tested for BSE, which does seem to be at odds with the hypothesis that it is a spontaneous disease. This is more a precautionary measure to maintain confidence in the beef trade and protect consumers while more knowledge about this disease is obtained.
Almost all current knowledge on atypical BSE is based on experimental infection because this spontaneous
VET RECORD | 29 March–12 April 2025
disease has generally only been found in aged downer cows, which is difficult to replicate experimentally in the host species. Intracerebral inoculation of brain tissue from an affected cow causes disease in cattle in less than two years, unlike the natural disease that usually occurs in animals over eight years of age.
The vast majority of cases have been identified by active monitoring of fallen stock or emergency slaughter of cattle, where only the brain sample of various stages of autolysis is generally available. Little is known of where the atypical BSE agent can be found in natural disease, other than in the brain, because all the cases confirmed have been identified after death through active surveillance, by which time most peripheral tissue has been disposed of. Limited material from a single case of a naturally affected cow was tested in Italy by mouse bioassay, which found infectivity in muscle.6 In experimental disease generated by intracerebral inoculation of cattle, infectivity can be detected in the brain and spinal cord, ganglia, peripheral nerves and skeletal muscles, similar to classical BSE, but not in peripheral lymphoid tissue.6–8
Early reporting of clinical suspects is needed so that the live animal or the whole carcase can be delivered to an APHA regional laboratory for tissue sampling. This is made more difficult due to the subtlety of clinical signs based on experimental disease. Clinical cases may not be as over- reactive or nervous as classical BSE cases; some may, in fact, be dull, but what most cases have in common is that they have difficulty getting up and eventually end up as downer cows, and only the clinical history may reveal some prior behavioural or locomotor changes. High creatinine kinase serum levels and nibbling in response to scratching the tail head or back were some features in experimental disease,8, 9 but it is not known whether this is also seen in natural disease.
In general, BSE should be considered as a differential diagnosis in all downer cows that do not respond to treatment, where the blood results do not support the presence of a metabolic disease and where the cause cannot be determined with confidence.
Since BSE is a notifiable disease, suspected cases of BSE in Great Britain must be reported to the local APHA office.
Changes are imminent in the reporting of fallen stock cattle, which will require the owner to state whether the animal displayed signs of changes in behaviour, sensation or locomotion before death, in addition to the likely cause of death or disease. This is to obtain a better profile of the clinical history, if cattle are retrospectively diagnosed as BSE cases, which has happened in all BSE cases confirmed since 2010: none has been reported as a clinical suspect.
“BSE should be considered as a differential diagnosis in all downer cows that do not respond to treatment”
Timm Konold, TSE lead scientist
Brenda Rajanayagam, workgroup leader for the data systems group
APHA Weybridge, New Haw, Addlestone, Surrey KT15 3NB email: timm.konold@apha.gov.uk
Keith Meldrum, former chief veterinary officer The Orchard, Swaynes Lane, Guildford, Surrey GU1 2XX
References
1 APHA. Cattle: TSE surveillance statistics. Overview of Great Britain statistics. 2025. https://bit.ly/4ho5Nds (accessed 19 March 2025)
Atypical BSE In Cattle
https://bvajournals.onlinelibrary.wiley.com/doi/abs/10.1002/vetr.5400?campaign=woletoc
Title: Transmission of atypical BSE: a possible origin of Classical BSE in cattle
Authors: Sandor Dudas1, Samuel James Sharpe1, Kristina Santiago-Mateo1, Stefanie Czub1, Waqas Tahir1,2, *
Affiliation: 1National and WOAH reference Laboratory for Bovine Spongiform Encephalopathy, Canadian Food inspection Agency, Lethbridge Laboratory, Lethbridge, Canada. 2Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
*Corresponding and Presenting Author: waqas.tahir@inspection.gc.ca
Background: Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disease of cattle and is categorized into classical and atypical forms. Classical BSE (CBSE) is linked to the consumption of BSE contaminated feed whereas atypical BSE is considered to be spontaneous in origin. The potential for oral transmission of atypical BSE is yet to be clearly defined.
Aims: To assess the oral transmissibility of atypical BSE (H and L type) in cattle. Should transmission be successful, determine the biochemical characteristics and distribution of PrPSc in the challenge cattle.
Material and Methods: For oral transmission, calves were fed with 100 g of either H (n=3) or L BSE (n=3) positive brain material. Two years post challenge, 1 calf from each of the H and L BSE challenge groups exhibited behavioural signs and were euthanized. Various brain regions of both animals were tested by traditional and novel prion detection methods with inconclusive results. To detect infectivity, brain homogenates from these oral challenge animals (P1) were injected intra-cranially (IC) into steer calves. Upon clinical signs of BSE, 3/4 of IC challenged steer calves were euthanized and tested for PrPSc with ELISA, immunohistochemistry and immunoblot.
Results: After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE.
Conclusion: These results demonstrate the oral transmission potential of atypical BSE in cattle. Surprisingly, regardless of which atypical type of BSE was used for P1 oral challenge, PrPSc in the P2 animals acquired biochemical characteristics similar to that of PrPSc in C-BSE, suggesting atypical BSE as a possible origin of C-BSE in UK.
Presentation Type: Oral Presentation
Funded by: CFIA, Health Canada, Alberta Livestock and Meat Agency, Alberta Prion Research Institute
Grant Number: ALMA/APRI: 201400006, HC 414250
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
OIE Conclusions on transmissibility of atypical BSE among cattle
Given that cattle have been successfully infected by the oral route, at least for L-BSE, it is reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle are exposed to contaminated feed. In addition, based on reports of atypical BSE from several countries that have not had C-BSE, it appears likely that atypical BSE would arise as a spontaneous disease in any country, albeit at a very low incidence in old cattle. In the presence of livestock industry practices that would allow it to be recycled in the cattle feed chain, it is likely that some level of exposure and transmission may occur. As a result, since atypical BSE can be reasonably considered to pose a potential background level of risk for any country with cattle, the recycling of both classical and atypical strains in the cattle and broader ruminant populations should be avoided.
https://www.oie.int/fileadmin/SST/adhocreports/Bovine%20spongiform%20encephalopathy/AN/A_AhG_BSEsurv_RiskAss_Mar2019.pdf
Annex 7 (contd) AHG on BSE risk assessment and surveillance/March 2019
34 Scientific Commission/September 2019
3. Atypical BSE
The Group discussed and endorsed with minor revisions an overview of relevant literature on the risk of atypical BSE being recycled in a cattle population and its zoonotic potential that had been prepared ahead of the meeting by one expert from the Group. This overview is provided as Appendix IV and its main conclusions are outlined below. With regard to the risk of recycling of atypical BSE, recently published research confirmed that the L-type BSE prion (a type of atypical BSE prion) may be orally transmitted to calves1 . In light of this evidence, and the likelihood that atypical BSE could arise as a spontaneous disease in any country, albeit at a very low incidence, the Group was of the opinion that it would be reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle were to be exposed to contaminated feed. Therefore, the recycling of atypical strains in cattle and broader ruminant populations should be avoided.
4. Definitions of meat-and-bone meal (MBM) and greaves
http://web.oie.int/downld/PROC2020/A_SCAD_Sept2019.pdf
The L-type BSE prion is much more virulent in primates and in humanized mice than is the classical BSE prion, which suggests the possibility of zoonotic risk associated with the L-type BSE prion
https://wwwnc.cdc.gov/eid/article/16/7/09-1882_article
Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5324790/
Thus, it is imperative to maintain measures that prevent the entry of tissues from cattle possibly infected with the agent of L-BSE into the food chain.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3310119/
Atypical L-type bovine spongiform encephalopathy (L-BSE) transmission to cynomolgus macaques, a non-human primate
Fumiko Ono 1, Naomi Tase, Asuka Kurosawa, Akio Hiyaoka, Atsushi Ohyama, Yukio Tezuka, Naomi Wada, Yuko Sato, Minoru Tobiume, Ken'ichi Hagiwara, Yoshio Yamakawa, Keiji Terao, Tetsutaro Sata
Affiliations expand
PMID: 21266763
Abstract
A low molecular weight type of atypical bovine spongiform encephalopathy (L-BSE) was transmitted to two cynomolgus macaques by intracerebral inoculation of a brain homogenate of cattle with atypical BSE detected in Japan. They developed neurological signs and symptoms at 19 or 20 months post-inoculation and were euthanized 6 months after the onset of total paralysis. Both the incubation period and duration of the disease were shorter than those for experimental transmission of classical BSE (C-BSE) into macaques. Although the clinical manifestations, such as tremor, myoclonic jerking, and paralysis, were similar to those induced upon C-BSE transmission, no premonitory symptoms, such as hyperekplexia and depression, were evident. Most of the abnormal prion protein (PrP(Sc)) was confined to the tissues of the central nervous system, as determined by immunohistochemistry and Western blotting. The PrP(Sc) glycoform that accumulated in the monkey brain showed a similar profile to that of L-BSE and consistent with that in the cattle brain used as the inoculant. PrP(Sc) staining in the cerebral cortex showed a diffuse synaptic pattern by immunohistochemistry, whereas it accumulated as fine and coarse granules and/or small plaques in the cerebellar cortex and brain stem. Severe spongiosis spread widely in the cerebral cortex, whereas florid plaques, a hallmark of variant Creutzfeldt-Jakob disease in humans, were observed in macaques inoculated with C-BSE but not in those inoculated with L-BSE.
https://pubmed.ncbi.nlm.nih.gov/21266763/
see full text;
https://www.niid.go.jp/niid/images/JJID/64/81.pdf
''H-TYPE BSE AGENT IS TRANSMISSIBLE BY THE ORONASAL ROUTE''
This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=353094
'Spontaneous mutation'
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
https://www.nature.com/articles/srep11573
US Report, Scrapie, CWD, Cattle, Sheep, Pigs, Cervid, Humans, Zoonotic, 2026
*** Grant Agreement number: 222887 ***
*** Project acronym: PRIORITY ***
*** Project title: Protecting the food chain from prions: shaping European priorities through basic and applied research Funding ***
Scheme: Large-scale integrating project Period covered: from Oct. 1, 2009 to Sept. 30, 2014
Name of the scientific representative of the project's co-ordinator1, Title and Organisation: Jesús R. Requena, Ph.D., Associate Professor, Department of medicine, University of Santiago de Compostela, Spàin. Tel: 34-881815464 Fax: 34-881815403 E-mail: jesus.requena@usc.es
Project website¡ Error! Marcador no definido. address: www.prionpriority.eu
PRIORITY, PROJECT FINAL REPORT
*** 14) Concluding that atypical scrapie can transmit to Humans and that its strain properties change as it transmits between species ***
snip...
http://cordis.europa.eu/docs/results/222/222887/final1-priority-final-report.pdf
see;
https://nor-98.blogspot.com/2016/09/goat-k222-prpc-polymorphic-variant-does.html
Block D: Prion epidemiology
Studies on atypical scrapie were identified as a key element of this block, given the potential risk associated to this agent. We studied the permeability of Human, bovine and porcine species barriers to atypical scrapie agent transmission. Experiments in transgenic mice expressing bovine, porcine or human PrPC suggest that this TSE agent has the intrinsic ability to propagate across these species barriers including the Human one. Upon species barrier passage the biological properties and phenotype of atypical scrapie seem to be altered. Further experiments are currently ongoing (in the framework of this project but also in other projects) in order to: (i) characterize the properties of the prion that emerged from the propagation of atypical scrapie in tg Hu; (ii) to confirm that the phenomena we observed are also true for atypical scrapie isolates other than the ones we have studied.
In parallel, studies in sheep have concluded that:
*** Atypical scrapie can be transmitted by both oral and intracerebral route in sheep with various PRP genotypes
*** Low but consistent amount of infectivity accumulates in peripheral tissue (mammary gland, lymph nodes, placenta, skeletal muscles, nerves) of sheep incubating atypical scrapie.
*** The combination of data from all our studies leads us to conclude that:
*** Atypical scrapie passage through species barriers can lead to the emergence of various prions including classical BSE (following propagation in porcine PRP transgenic mice).
*** Atypical scrapie can propagate, with a low efficacy, in human PrP expressing mice. This suggests the existence of a zoonotic potential for this TSE agent.
snip...
We advance our main conclusions and recommendations, in particular as they might affect public policy, including a detailed elaboration of the evidence that led to them. Our main recommendations are:
a. The issue of re-introducing ruminant protein into the food-chain The opinion of the members of Priority is that sustaining an absolute feed ban for ruminant protein to ruminants is the essential requirement, especially since the impact of non-classical forms of scrapie in sheep and goats is not fully understood and cannot be fully estimated. Therefore, the consortium strongly recommends prohibiting re-introduction of processed ruminant protein into the food-chain. Arguments in support of this opinion are:
• the large (and still uncharacterized) diversity of prion agents that circulate in animal populations;
• the uncertainties related to prion epidemiology in animal populations;
• the unknown efficacy of industrial processes applied to reduce microbiological risk during processed animal protein (PAP) production on most prion agents; • the intrinsic capacity of prions to cross interspecies transmission barriers; • the lack of sensitive methodology for identifying cross contamination in food.
• the evolution of natural food chains in nature (i.e. who eats whom or what) has generated an efficient barrier preventing, to some extent, novel prion epidemies and that this naturally evolved ecology should be respected.
The consortium is also hesitant to introduce processed ruminant proteins into fish food considering the paucity of data on prion infections in fishes and sea animals including those of mammalian origin, and the risk of establishing an environmental contamination of the oceans that cannot be controlled.
b. Atypical prion agents and surveillance
Atypical prion agents (see below) will probably continue to represent the dominant form of prion diseases in the near future, particularly in Europe.
*** Atypical L-type BSE has clear zoonotic potential, as demonstrated in experimental models.
*** Similarly, there are now some data that seem to indicate that the atypical scrapie agent can cross various species barriers.
*** Moreover, the current EU policy for eradicating scrapie (genetic selection in affected flocks) is ineffective for preventing atypical scrapie.
*** The recent identification of cell-to-cell propagation and the protein-encoded strain properties of human neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, suggest that they bear the potential to be transmissible even if not with the same efficiency as CJD. More epidemiological data from large cohorts are necessary to reach any conclusion on the impact of their transmissibility on public health. Re-evaluations of safety precautions may become necessary depending on the outcome of these studies. In that context it would appear valuable
• to develop knowledge related to the pathogenesis and inter-individual transmission of atypical prion agents in ruminants (both intra- and inter-species)
• to improve the sensitivity of detection assays that are applied in the field towards this type of agent
• to maintain a robust surveillance of both animal and human populations
c. The need for extended research on prions
Intensified searching for a molecular determinants of the species barrier is recommended, since this barrier is a key for many important policy areas - risk assessment, proportional policies, the need for screening of human products and food. In this respect, prion strain structural language also remains an important issue for public health for the foreseeable future. Understanding the structural basis for strains and the basis for adaptation of a strain to a new host will require continued fundamental research. Prions maintain a complex two-way relationship with the host cell and fundamental research is needed on mechanisms for their transmission, replication and cause of nervous system dysfunction and death.
Early detection of prion infection, ideally at preclinical stage, also remains crucial for development of effective treatment strategies in humans affected by the disease.
Position of the Priority consortium
Nearly 30 years ago, the appearance in the UK of Bovine Spongiform Encephalopathy (BSE) quickly brought the previously obscure “prion diseases” to the spotlight. The ensuing health and food crises that spread throughout Europe had devastating consequences. In the UK alone, there were more than 36,000 farms directly affected by BSE and the transmission of BSE prions to humans via the food chain has caused over 200 people in Europe to die from variant Creutzfeldt-Jakob disease (vCJD) (http://www.cjd.ed.ac.uk
Origins of prion epidemies
Classical BSE now appears to be under control, with 18 EU Member States having achieved the World Organisation for Animal Health (Office International Epizooties) „negligible risk‟ status (May 2014; http://www.oie.int/en/animal-health-in-the-world/official-disease-status/bse/list-of-bse-risk-status/), and the remaining MS assessed as „controlled‟ risk. Of note, research, including EU-funded research, has played a key role in this success: while the origin of the infection was never defined, the principle driver of the epidemic was identified as prions in Meat and Bone Meal (MBM). Tests based on prion protein-specific antibodies were developed, allowing detection of infected animals, and a better understanding of disease pathogenesis and the distribution of infectivity in edible tissues; experimental investigation of transmission barriers between different species allowed a rational estimation of risks, etc. All of this led to the implementation of rational and effective policies, such as the MBM ban to protect the animal feed chain, and the Specified Risk Material (SRM) regulations to protect the human food chain.
In spite of this progress, prions are still a threat. Epidemiological re-assessment indicates that the ∼10 year incubation period separating the peaks of the BSE and the vCJD epidemics is probably too short. In addition, results from a large number of human tonsil and appendix analyses in the UK suggest that there may be a high number of asymptomatic individuals who are positive for the disease-associated conformer prion protein PrPSc. While vCJD is the only form of human prion disease that has been consistently demonstrated to have lymphoreticular involvement, there has been no systematic investigation of lymphoid tissue in cases with other prion diseases.
The human prion problem
The clinical cases of vCJD identified to date have all shared a common PrP genotype (M129M), although one pre-clinical case was confirmed as an M129V heterozygote, and it has been mooted that perhaps only the M129M proportion of the population is susceptible. However, in the UK appendix study, PrP accumulation was described in samples representing every codon 129 genotype, raising the possibility that genotype does not confer resistance but instead modulates incubation period. Apart from the two UK studies, the lymphoid tissues of non-CJD patients have not been examined for the presence of PrPSc, so, these cases may not solely represent pre-clinical vCJD, but also other forms of prion disease.
Recent experiments in highly susceptible mouse models indicate the presence of infectivity in blood or blood components at late disease stages in sporadic CJD. The significance of this experimental finding for humans has to be explored in more detail and, at the present time, there is no evidence for the transmission of prions via blood in sporadic CJD. However a likely scenario is that all those with signs of infection or abnormal PrP accumulation in peripheral tissue could have infective blood, posing the risk for transmission via blood products, which has been clearly demonstrated in experimental models, and confirmed in several cases of vCJD in man. Altogether, these data clearly demonstrate the potential risk of a second wave of vCJD, particularly when the number people identified with lymphoid accumulation of PrPSc (16/32,411) gives a prevalence estimate in the UK of 493 per million, much higher than the number of clinical cases seen to date.
The animal prion problem
An increasing number of reports on cases of “atypical” BSE in cattle throughout the EU and beyond may lead to a new epidemic, particularly since we still do not understand all factors determining the species barrier. Ovine scrapie is another concern, because it could mask ovine BSE, presumably transmissible to humans. Scrapie is endemic and not likely to be eradicated soon, although current control measures are effective at greatly reducing disease incidence. Atypical forms, which may be spontaneous, are not affected by these control measures and these forms of disease will persist in the global animal population. The low prevalence of these disease forms makes effective surveillance very challenging. However, there is a clear risk attendant on ignoring these cases without an understanding of their possible zoonotic potential, particularly when most forms of human disease have no established aetiology. In summary, atypical cases of BSE and scrapie presently clearly outnumber classical cases in cattle and sheep in all member states.
We will highlight the state-of-the-art knowledge and point out scientific challenges and the major questions for research. Strategic objectives and priorities in Europe in the future for research that aims to control, eliminate or eradicate the threat posed by prions to our food and health are also indicated.
The Priority project has focused on 4 themes, namely the structure, function, conversion and toxicity of prions; detection of prions; mechanisms of prion transmission and spreading and epidemiology of prion diseases. This paper summarizes the opinions/positions reached within these themes at the end of the project.
http://cordis.europa.eu/docs/results/222/222887/final1-priority-final-report.pdf
see;
https://nor-98.blogspot.com/2016/09/goat-k222-prpc-polymorphic-variant-does.html
Transmission of scrapie prions to primate after an extended silent incubation period
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
==============
PRION 2015 CONFERENCE
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5019500/
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-68961933-690X
WS-01: Prion diseases in animals and zoonotic potential
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
Comparing the Distribution of Ovine Classical Scrapie and Sporadic Creutzfeldt-Jakob Disease in Italy: Spatial and Temporal Associations (2002-2014)
Ru G1 ., Pocchiari M2 ., Bertolini S. 1, Pite L.1 , Puopolo M.2 , Ladogana A.2 , Perrotta M.G.3 , Meloni D 1 . (1) National reference center for the study and research on animal encephalopathies and comparative neuropathologies (CEA). Experimental Zooprophylactic Institute of Piemonte, Liguria and Valle d'Aosta, Torino, Italy.
(2) Department of Cellular Biology and Neuroscience, Istituto Superiore di Sanità, Roma, Italy. (3) Office 3 National center for the fight and emergency against animal diseases. Ministry of Health, Roma, Italy.
Aim: This study aims to investigate potential spatial and temporal associations between Creutzfeldt-Jakob disease (CJD) in humans (2010-2014) and ovine classical scrapie (CS) (2002- 2006) in Italy, serving as a proxy for exposure.
Materials and Methods: National data from prion disease surveillance in humans (sporadic CJD) and small ruminants (CS) in Italy were utilized. A descriptive geographic analysis was conducted for each disease individually. Subsequently, an ecological study was performed to compare the occurrence of both diseases at the district and regional levels. Standardized incidence ratios (SIR), adjusted for confounders, were calculated for CJD and CS by district and region, respectively, representing the outcome and proxy of exposure. Considering a possible long incubation period of CJD, two study periods were analysed: 2010-2014 for CJD and 2002-2006 for CS. Eight alternative linear regression models were developed using SIR in humans as the dependent variable and SIR in sheep as the independent variable. These models varied in the scale of SIR data (continuous vs. categorical), geographical level (district vs. region), and the potential past exposure of sheep in specific areas to a known source of infection (via a contaminated vaccine).
Results: The analysis of data at the district level revealed no significant association. However, when considering aggregated regional data, all four models consistently indicated a statistically significant positive association, suggesting a higher incidence of the disease in humans as the regional incidence of sheep scrapie increased.
Conclusions: While the results are intriguing, it is important to acknowledge the inherent limitations of ecological studies. Nevertheless, these findings provide valuable evidence to formulate a hypothesis regarding the zoonotic potential of classical scrapie. Further investigations are necessary, employing specific designs such as analytical epidemiology studies, to test this hypothesis effectively.
Funded by: Italian Ministry of Health Grant number: Realizzazione del programma epidemiologico finalizzato a dare evidenza del potenziale zoonotico delle TSE animali diverse dalla BSE. Prot. N. 0018730-17/07/2015-DGSAFCOD_UO-P
''Nevertheless, these findings provide valuable evidence to formulate a hypothesis regarding the zoonotic potential of classical scrapie. Further investigations are necessary, employing specific designs such as analytical epidemiology studies, to test this hypothesis effectively.''
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Canadian 2021 H-type Bovine Spongiform Encephalopathy case associated with a novel E211K polymorphism in prion protein gene novel E211K polymorphism in prion protein gene
Waqas Tahir , Sandor Dudas , Renee Anderson , Jianmin Yang , Sarah Bogart , Kristina Santiago-Mateo, Yuanmu Fang & Roberta Quaghebeur
Pages 36-49 | Received 20 Feb 2025, Accepted 22 May 2025, Published online: 04 Aug 2025 Cite this article https://doi.org/10.1080/19336896.2025.2511933
ABSTRACT
Bovine Spongiform Encephalopathy (BSE) is a fatal neurodegenerative disease in cattle which can be either classical BSE (C-BSE) or atypical BSE (including H-BSE and L-BSE). Here, we report the results of our analyses of an H-BSE case found in Canada in 2021, indicating restriction of the pathological agent (PrPSc) mainly to the central nervous system with no or occasional weak involvement of peripheral tissues. Importantly, a non-synonymous mutation at codon 211 of the PRNP gene was detected and confirmed to be present as a germline mutation. This is the first case of BSE in Canada with a predisposing E211K mutation.
Snip…
Based on the results of this study, and the 2006 H-BSE case in the USA, there is an expanded spectrum of aetiologies for bovine prion diseases similar to what is observed in humans, including sporadic, genetic and acquired versions.
Supplemental material Canadian 2021 H-type Bovine Spongiform Encephalopathy case associated with a novel E211K polymorphism in prion protein gene
KEYWORDS:
Atypical BSEBovine Spongiform Encephalopathycentral nervous systemE211K mutationprion diseasesprion protein genesynonymous mutation
https://www.tandfonline.com/doi/full/10.1080/19336896.2025.2511933#d1e1606
“Based on the results of this study, and the 2006 H-BSE case in the USA, there is an expanded spectrum of aetiologies for bovine prion diseases similar to what is observed in humans, including sporadic, genetic and acquired versions.”
MONDAY, JUNE 09, 2025
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
OIE Conclusions on transmissibility of atypical BSE among cattle
Given that cattle have been successfully infected by the oral route, at least for L-BSE, it is reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle are exposed to contaminated feed. In addition, based on reports of atypical BSE from several countries that have not had C-BSE, it appears likely that atypical BSE would arise as a spontaneous disease in any country, albeit at a very low incidence in old cattle. In the presence of livestock industry practices that would allow it to be recycled in the cattle feed chain, it is likely that some level of exposure and transmission may occur. As a result, since atypical BSE can be reasonably considered to pose a potential background level of risk for any country with cattle, the recycling of both classical and atypical strains in the cattle and broader ruminant populations should be avoided.
https://www.oie.int/fileadmin/SST/adhocreports/Bovine%20spongiform%20encephalopathy/AN/A_AhG_BSEsurv_RiskAss_Mar2019.pdf
Annex 7 (contd) AHG on BSE risk assessment and surveillance/March 2019
34 Scientific Commission/September 2019
3. Atypical BSE
The Group discussed and endorsed with minor revisions an overview of relevant literature on the risk of atypical BSE being recycled in a cattle population and its zoonotic potential that had been prepared ahead of the meeting by one expert from the Group. This overview is provided as Appendix IV and its main conclusions are outlined below. With regard to the risk of recycling of atypical BSE, recently published research confirmed that the L-type BSE prion (a type of atypical BSE prion) may be orally transmitted to calves1 . In light of this evidence, and the likelihood that atypical BSE could arise as a spontaneous disease in any country, albeit at a very low incidence, the Group was of the opinion that it would be reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle were to be exposed to contaminated feed. Therefore, the recycling of atypical strains in cattle and broader ruminant populations should be avoided.
4. Definitions of meat-and-bone meal (MBM) and greaves
http://web.oie.int/downld/PROC2020/A_SCAD_Sept2019.pdf
The L-type BSE prion is much more virulent in primates and in humanized mice than is the classical BSE prion, which suggests the possibility of zoonotic risk associated with the L-type BSE prion
https://wwwnc.cdc.gov/eid/article/16/7/09-1882_article
Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5324790/
Thus, it is imperative to maintain measures that prevent the entry of tissues from cattle possibly infected with the agent of L-BSE into the food chain.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3310119/
Atypical L-type bovine spongiform encephalopathy (L-BSE) transmission to cynomolgus macaques, a non-human primate
Fumiko Ono 1, Naomi Tase, Asuka Kurosawa, Akio Hiyaoka, Atsushi Ohyama, Yukio Tezuka, Naomi Wada, Yuko Sato, Minoru Tobiume, Ken'ichi Hagiwara, Yoshio Yamakawa, Keiji Terao, Tetsutaro Sata
Affiliations expand
PMID: 21266763
Abstract
A low molecular weight type of atypical bovine spongiform encephalopathy (L-BSE) was transmitted to two cynomolgus macaques by intracerebral inoculation of a brain homogenate of cattle with atypical BSE detected in Japan. They developed neurological signs and symptoms at 19 or 20 months post-inoculation and were euthanized 6 months after the onset of total paralysis. Both the incubation period and duration of the disease were shorter than those for experimental transmission of classical BSE (C-BSE) into macaques. Although the clinical manifestations, such as tremor, myoclonic jerking, and paralysis, were similar to those induced upon C-BSE transmission, no premonitory symptoms, such as hyperekplexia and depression, were evident. Most of the abnormal prion protein (PrP(Sc)) was confined to the tissues of the central nervous system, as determined by immunohistochemistry and Western blotting. The PrP(Sc) glycoform that accumulated in the monkey brain showed a similar profile to that of L-BSE and consistent with that in the cattle brain used as the inoculant. PrP(Sc) staining in the cerebral cortex showed a diffuse synaptic pattern by immunohistochemistry, whereas it accumulated as fine and coarse granules and/or small plaques in the cerebellar cortex and brain stem. Severe spongiosis spread widely in the cerebral cortex, whereas florid plaques, a hallmark of variant Creutzfeldt-Jakob disease in humans, were observed in macaques inoculated with C-BSE but not in those inoculated with L-BSE.
https://pubmed.ncbi.nlm.nih.gov/21266763/
see full text;
https://www.niid.go.jp/niid/images/JJID/64/81.pdf
''H-TYPE BSE AGENT IS TRANSMISSIBLE BY THE ORONASAL ROUTE''
This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=353094
'Spontaneous mutation'
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
https://www.nature.com/articles/srep11573
US Report, Scrapie, CWD, Cattle, Sheep, Pigs, Cervid, Humans, Zoonotic, 2026
*** Grant Agreement number: 222887 ***
*** Project acronym: PRIORITY ***
*** Project title: Protecting the food chain from prions: shaping European priorities through basic and applied research Funding ***
Scheme: Large-scale integrating project Period covered: from Oct. 1, 2009 to Sept. 30, 2014
Name of the scientific representative of the project's co-ordinator1, Title and Organisation: Jesús R. Requena, Ph.D., Associate Professor, Department of medicine, University of Santiago de Compostela, Spàin. Tel: 34-881815464 Fax: 34-881815403 E-mail: jesus.requena@usc.es
Project website¡ Error! Marcador no definido. address: www.prionpriority.eu
PRIORITY, PROJECT FINAL REPORT
*** 14) Concluding that atypical scrapie can transmit to Humans and that its strain properties change as it transmits between species ***
snip...
http://cordis.europa.eu/docs/results/222/222887/final1-priority-final-report.pdf
see;
https://nor-98.blogspot.com/2016/09/goat-k222-prpc-polymorphic-variant-does.html
Block D: Prion epidemiology
Studies on atypical scrapie were identified as a key element of this block, given the potential risk associated to this agent. We studied the permeability of Human, bovine and porcine species barriers to atypical scrapie agent transmission. Experiments in transgenic mice expressing bovine, porcine or human PrPC suggest that this TSE agent has the intrinsic ability to propagate across these species barriers including the Human one. Upon species barrier passage the biological properties and phenotype of atypical scrapie seem to be altered. Further experiments are currently ongoing (in the framework of this project but also in other projects) in order to: (i) characterize the properties of the prion that emerged from the propagation of atypical scrapie in tg Hu; (ii) to confirm that the phenomena we observed are also true for atypical scrapie isolates other than the ones we have studied.
In parallel, studies in sheep have concluded that:
*** Atypical scrapie can be transmitted by both oral and intracerebral route in sheep with various PRP genotypes
*** Low but consistent amount of infectivity accumulates in peripheral tissue (mammary gland, lymph nodes, placenta, skeletal muscles, nerves) of sheep incubating atypical scrapie.
*** The combination of data from all our studies leads us to conclude that:
*** Atypical scrapie passage through species barriers can lead to the emergence of various prions including classical BSE (following propagation in porcine PRP transgenic mice).
*** Atypical scrapie can propagate, with a low efficacy, in human PrP expressing mice. This suggests the existence of a zoonotic potential for this TSE agent.
snip...
We advance our main conclusions and recommendations, in particular as they might affect public policy, including a detailed elaboration of the evidence that led to them. Our main recommendations are:
a. The issue of re-introducing ruminant protein into the food-chain The opinion of the members of Priority is that sustaining an absolute feed ban for ruminant protein to ruminants is the essential requirement, especially since the impact of non-classical forms of scrapie in sheep and goats is not fully understood and cannot be fully estimated. Therefore, the consortium strongly recommends prohibiting re-introduction of processed ruminant protein into the food-chain. Arguments in support of this opinion are:
• the large (and still uncharacterized) diversity of prion agents that circulate in animal populations;
• the uncertainties related to prion epidemiology in animal populations;
• the unknown efficacy of industrial processes applied to reduce microbiological risk during processed animal protein (PAP) production on most prion agents; • the intrinsic capacity of prions to cross interspecies transmission barriers; • the lack of sensitive methodology for identifying cross contamination in food.
• the evolution of natural food chains in nature (i.e. who eats whom or what) has generated an efficient barrier preventing, to some extent, novel prion epidemies and that this naturally evolved ecology should be respected.
The consortium is also hesitant to introduce processed ruminant proteins into fish food considering the paucity of data on prion infections in fishes and sea animals including those of mammalian origin, and the risk of establishing an environmental contamination of the oceans that cannot be controlled.
b. Atypical prion agents and surveillance
Atypical prion agents (see below) will probably continue to represent the dominant form of prion diseases in the near future, particularly in Europe.
*** Atypical L-type BSE has clear zoonotic potential, as demonstrated in experimental models.
*** Similarly, there are now some data that seem to indicate that the atypical scrapie agent can cross various species barriers.
*** Moreover, the current EU policy for eradicating scrapie (genetic selection in affected flocks) is ineffective for preventing atypical scrapie.
*** The recent identification of cell-to-cell propagation and the protein-encoded strain properties of human neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, suggest that they bear the potential to be transmissible even if not with the same efficiency as CJD. More epidemiological data from large cohorts are necessary to reach any conclusion on the impact of their transmissibility on public health. Re-evaluations of safety precautions may become necessary depending on the outcome of these studies. In that context it would appear valuable
• to develop knowledge related to the pathogenesis and inter-individual transmission of atypical prion agents in ruminants (both intra- and inter-species)
• to improve the sensitivity of detection assays that are applied in the field towards this type of agent
• to maintain a robust surveillance of both animal and human populations
c. The need for extended research on prions
Intensified searching for a molecular determinants of the species barrier is recommended, since this barrier is a key for many important policy areas - risk assessment, proportional policies, the need for screening of human products and food. In this respect, prion strain structural language also remains an important issue for public health for the foreseeable future. Understanding the structural basis for strains and the basis for adaptation of a strain to a new host will require continued fundamental research. Prions maintain a complex two-way relationship with the host cell and fundamental research is needed on mechanisms for their transmission, replication and cause of nervous system dysfunction and death.
Early detection of prion infection, ideally at preclinical stage, also remains crucial for development of effective treatment strategies in humans affected by the disease.
Position of the Priority consortium
Nearly 30 years ago, the appearance in the UK of Bovine Spongiform Encephalopathy (BSE) quickly brought the previously obscure “prion diseases” to the spotlight. The ensuing health and food crises that spread throughout Europe had devastating consequences. In the UK alone, there were more than 36,000 farms directly affected by BSE and the transmission of BSE prions to humans via the food chain has caused over 200 people in Europe to die from variant Creutzfeldt-Jakob disease (vCJD) (http://www.cjd.ed.ac.uk
Origins of prion epidemies
Classical BSE now appears to be under control, with 18 EU Member States having achieved the World Organisation for Animal Health (Office International Epizooties) „negligible risk‟ status (May 2014; http://www.oie.int/en/animal-health-in-the-world/official-disease-status/bse/list-of-bse-risk-status/), and the remaining MS assessed as „controlled‟ risk. Of note, research, including EU-funded research, has played a key role in this success: while the origin of the infection was never defined, the principle driver of the epidemic was identified as prions in Meat and Bone Meal (MBM). Tests based on prion protein-specific antibodies were developed, allowing detection of infected animals, and a better understanding of disease pathogenesis and the distribution of infectivity in edible tissues; experimental investigation of transmission barriers between different species allowed a rational estimation of risks, etc. All of this led to the implementation of rational and effective policies, such as the MBM ban to protect the animal feed chain, and the Specified Risk Material (SRM) regulations to protect the human food chain.
In spite of this progress, prions are still a threat. Epidemiological re-assessment indicates that the ∼10 year incubation period separating the peaks of the BSE and the vCJD epidemics is probably too short. In addition, results from a large number of human tonsil and appendix analyses in the UK suggest that there may be a high number of asymptomatic individuals who are positive for the disease-associated conformer prion protein PrPSc. While vCJD is the only form of human prion disease that has been consistently demonstrated to have lymphoreticular involvement, there has been no systematic investigation of lymphoid tissue in cases with other prion diseases.
The human prion problem
The clinical cases of vCJD identified to date have all shared a common PrP genotype (M129M), although one pre-clinical case was confirmed as an M129V heterozygote, and it has been mooted that perhaps only the M129M proportion of the population is susceptible. However, in the UK appendix study, PrP accumulation was described in samples representing every codon 129 genotype, raising the possibility that genotype does not confer resistance but instead modulates incubation period. Apart from the two UK studies, the lymphoid tissues of non-CJD patients have not been examined for the presence of PrPSc, so, these cases may not solely represent pre-clinical vCJD, but also other forms of prion disease.
Recent experiments in highly susceptible mouse models indicate the presence of infectivity in blood or blood components at late disease stages in sporadic CJD. The significance of this experimental finding for humans has to be explored in more detail and, at the present time, there is no evidence for the transmission of prions via blood in sporadic CJD. However a likely scenario is that all those with signs of infection or abnormal PrP accumulation in peripheral tissue could have infective blood, posing the risk for transmission via blood products, which has been clearly demonstrated in experimental models, and confirmed in several cases of vCJD in man. Altogether, these data clearly demonstrate the potential risk of a second wave of vCJD, particularly when the number people identified with lymphoid accumulation of PrPSc (16/32,411) gives a prevalence estimate in the UK of 493 per million, much higher than the number of clinical cases seen to date.
The animal prion problem
An increasing number of reports on cases of “atypical” BSE in cattle throughout the EU and beyond may lead to a new epidemic, particularly since we still do not understand all factors determining the species barrier. Ovine scrapie is another concern, because it could mask ovine BSE, presumably transmissible to humans. Scrapie is endemic and not likely to be eradicated soon, although current control measures are effective at greatly reducing disease incidence. Atypical forms, which may be spontaneous, are not affected by these control measures and these forms of disease will persist in the global animal population. The low prevalence of these disease forms makes effective surveillance very challenging. However, there is a clear risk attendant on ignoring these cases without an understanding of their possible zoonotic potential, particularly when most forms of human disease have no established aetiology. In summary, atypical cases of BSE and scrapie presently clearly outnumber classical cases in cattle and sheep in all member states.
We will highlight the state-of-the-art knowledge and point out scientific challenges and the major questions for research. Strategic objectives and priorities in Europe in the future for research that aims to control, eliminate or eradicate the threat posed by prions to our food and health are also indicated.
The Priority project has focused on 4 themes, namely the structure, function, conversion and toxicity of prions; detection of prions; mechanisms of prion transmission and spreading and epidemiology of prion diseases. This paper summarizes the opinions/positions reached within these themes at the end of the project.
http://cordis.europa.eu/docs/results/222/222887/final1-priority-final-report.pdf
see;
https://nor-98.blogspot.com/2016/09/goat-k222-prpc-polymorphic-variant-does.html
Transmission of scrapie prions to primate after an extended silent incubation period
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
==============
PRION 2015 CONFERENCE
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5019500/
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-68961933-690X
WS-01: Prion diseases in animals and zoonotic potential
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
Comparing the Distribution of Ovine Classical Scrapie and Sporadic Creutzfeldt-Jakob Disease in Italy: Spatial and Temporal Associations (2002-2014)
Ru G1 ., Pocchiari M2 ., Bertolini S. 1, Pite L.1 , Puopolo M.2 , Ladogana A.2 , Perrotta M.G.3 , Meloni D 1 . (1) National reference center for the study and research on animal encephalopathies and comparative neuropathologies (CEA). Experimental Zooprophylactic Institute of Piemonte, Liguria and Valle d'Aosta, Torino, Italy.
(2) Department of Cellular Biology and Neuroscience, Istituto Superiore di Sanità, Roma, Italy. (3) Office 3 National center for the fight and emergency against animal diseases. Ministry of Health, Roma, Italy.
Aim: This study aims to investigate potential spatial and temporal associations between Creutzfeldt-Jakob disease (CJD) in humans (2010-2014) and ovine classical scrapie (CS) (2002- 2006) in Italy, serving as a proxy for exposure.
Materials and Methods: National data from prion disease surveillance in humans (sporadic CJD) and small ruminants (CS) in Italy were utilized. A descriptive geographic analysis was conducted for each disease individually. Subsequently, an ecological study was performed to compare the occurrence of both diseases at the district and regional levels. Standardized incidence ratios (SIR), adjusted for confounders, were calculated for CJD and CS by district and region, respectively, representing the outcome and proxy of exposure. Considering a possible long incubation period of CJD, two study periods were analysed: 2010-2014 for CJD and 2002-2006 for CS. Eight alternative linear regression models were developed using SIR in humans as the dependent variable and SIR in sheep as the independent variable. These models varied in the scale of SIR data (continuous vs. categorical), geographical level (district vs. region), and the potential past exposure of sheep in specific areas to a known source of infection (via a contaminated vaccine).
Results: The analysis of data at the district level revealed no significant association. However, when considering aggregated regional data, all four models consistently indicated a statistically significant positive association, suggesting a higher incidence of the disease in humans as the regional incidence of sheep scrapie increased.
Conclusions: While the results are intriguing, it is important to acknowledge the inherent limitations of ecological studies. Nevertheless, these findings provide valuable evidence to formulate a hypothesis regarding the zoonotic potential of classical scrapie. Further investigations are necessary, employing specific designs such as analytical epidemiology studies, to test this hypothesis effectively.
Funded by: Italian Ministry of Health Grant number: Realizzazione del programma epidemiologico finalizzato a dare evidenza del potenziale zoonotico delle TSE animali diverse dalla BSE. Prot. N. 0018730-17/07/2015-DGSAFCOD_UO-P
''Nevertheless, these findings provide valuable evidence to formulate a hypothesis regarding the zoonotic potential of classical scrapie. Further investigations are necessary, employing specific designs such as analytical epidemiology studies, to test this hypothesis effectively.''
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Canadian 2021 H-type Bovine Spongiform Encephalopathy case associated with a novel E211K polymorphism in prion protein gene novel E211K polymorphism in prion protein gene
Waqas Tahir , Sandor Dudas , Renee Anderson , Jianmin Yang , Sarah Bogart , Kristina Santiago-Mateo, Yuanmu Fang & Roberta Quaghebeur
Pages 36-49 | Received 20 Feb 2025, Accepted 22 May 2025, Published online: 04 Aug 2025 Cite this article https://doi.org/10.1080/19336896.2025.2511933
ABSTRACT
Bovine Spongiform Encephalopathy (BSE) is a fatal neurodegenerative disease in cattle which can be either classical BSE (C-BSE) or atypical BSE (including H-BSE and L-BSE). Here, we report the results of our analyses of an H-BSE case found in Canada in 2021, indicating restriction of the pathological agent (PrPSc) mainly to the central nervous system with no or occasional weak involvement of peripheral tissues. Importantly, a non-synonymous mutation at codon 211 of the PRNP gene was detected and confirmed to be present as a germline mutation. This is the first case of BSE in Canada with a predisposing E211K mutation.
Snip…
Based on the results of this study, and the 2006 H-BSE case in the USA, there is an expanded spectrum of aetiologies for bovine prion diseases similar to what is observed in humans, including sporadic, genetic and acquired versions.
Supplemental material Canadian 2021 H-type Bovine Spongiform Encephalopathy case associated with a novel E211K polymorphism in prion protein gene
KEYWORDS:
Atypical BSEBovine Spongiform Encephalopathycentral nervous systemE211K mutationprion diseasesprion protein genesynonymous mutation
https://www.tandfonline.com/doi/full/10.1080/19336896.2025.2511933#d1e1606
“Based on the results of this study, and the 2006 H-BSE case in the USA, there is an expanded spectrum of aetiologies for bovine prion diseases similar to what is observed in humans, including sporadic, genetic and acquired versions.”
MONDAY, JUNE 09, 2025
The naturally occurring lysine to glutamic acid substitution (E211K in the bovine prion protein) results in short incubation periods for H-type bovine spongioform encephalopathy (BSE) The naturally occurring lysine to glutamic acid substitution (E211K in the bovine prion protein) results in short incubation periods for H-type bovine spongioform encephalopathy (BSE)
Component 6: Transmissible Spongiform Encephalopathies (TSEs)
Problem Statement 6A: Determine pathobiology of prion strains.
The naturally occurring lysine to glutamic acid substitution (E211K in the bovine prion protein) results in short incubation periods for H-type bovine spongioform encephalopathy (BSE).
Virus and Prion Research Unit, National Animal Disease Center, Ames, Iowa
Classical BSE (C-BSE) is a prion disease of cattle that was responsible for the "mad cow disease" epizootic in Europe in the 1980s. C-BSE was determined to cause the human prion disease vCJD. Since then, atypical spontaneous strains of BSE were identified. H-BSE is one of those strains. Much research has explored the origins of C-BSE, and strain emergence from atypical H-BSE is one hypothesis. An H-BSE case was determined to have a germline mutation, an E211K substitution in the prion protein gene, which is analogous to a hereditary human prion disease. ARS scientists in Ames, Iowa reported the transmission of H-BSE from cattle, with and without the germline prion protein amino acid substitution, to cattle with various prion genotypes: EE211 (wild-type), EK211, and KK211. Results indicated a significantly shorter incubation period in K containing cattle compared to prion wild-type cattle. The scientists also explored the possibility that the C-BSE strain might have occurred after serial passages of EK211 and KK211 containing H-BSE in cattle, but results did not support this concept. This information is important to prion researchers, veterinary diagnostic laboratories, and those involved with establishing regulatory guidelines.
https://www.ars.usda.gov/ARSUserFiles/np103/AnnualReports/Final%20NP103%20FY2024%20Annual%20Report.updated%205.30.25.pdf
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: Cattle with the EK211 PRNP polymorphism are susceptible to the H-type bovine spongiform encephalopathy agent from either E211K or wild type donors after oronasal inoculation
Author item Greenlee, Justin item Cassmann, Eric item MOORE, SARA JO - Oak Ridge Institute For Science And Education (ORISE) item WEST GREENLEE, HEATHER - Iowa State University
Submitted to: Meeting Abstract Publication Type: Abstract Only Publication Acceptance Date: 6/24/2022 Publication Date: 9/16/2022 Citation: Greenlee, J.J., Cassmann, E.D., Moore, S., West Greenlee, H.M. 2022.
Cattle with the EK211 PRNP polymorphism are susceptible to the H-type bovine spongiform encephalopathy agent from either E211K or wild type donors after oronasal inoculation.
Prion 2022 Conference abstracts: pushing the boundaries. 16(1):150. https://doi.org/10.1080/19336896.2022.2091286.
DOI: https://doi.org/10.1080/19336896.2022.2091286
Interpretive Summary:
Technical Abstract: In 2006, a case of H-type bovine spongiform encephalopathy (H-BSE) was reported in a cow with a previously unreported prion protein polymorphism (E211K). The E211K polymorphism is heritable and homologous to the E200K mutation in humans that is the most frequent PRNP mutation associated with familial Creutzfeldt-Jakob disease. Although the prevalence of the E211K polymorphism is low, cattle carrying the K211 allele develop H-type BSE with a rapid onset after experimental inoculation by the intracranial route. The purpose of this study was to investigate whether the agents of H-type BSE or H-type BSE associated with the E211K polymorphism transmit to wild type cattle or cattle with the K211 allele after oronasal exposure. Wild type (EE211) or heterozygous (EK211) cattle were oronasally inoculated with the H-BSE agent from either the US 2004 case (wild type donor; n=3) or from the US 2006 case with the E211K polymorphism (n=4). Cattle were observed daily throughout the course of the experiment for the development of clinical signs. When signs were noted, animals were euthanized and necropsied. Cattle were confirmed positive for abnormal BSE prions by enzyme immunoassay (EIA; Idexx HerdChek BSE Ag Test), anti-PrP immunohistochemistry (IHC) on brainstem, and microscopic examination for vacuolation. Three-out-of-four (75%) calves with the EK211 genotype developed clinical signs of H-BSE including inattentiveness, loss of body condition, weakness, ataxia, and muscle fasciculations and were euthanized. Two of the positive EK211 steers received H-BSE US 2004 inoculum (Incubation Period (IP): 59.3 and 72.3 months) while the other positive steer received the E211K H-BSE inoculum (IP: 49.7 months). EIA confirmed that abundant misfolded protein (O.D. 2.57-4.0) in the brainstem, and IHC demonstrated PrPSc throughout the brain. All cattle in the EE211 recipient group remain asymptomatic for the duration of the experiment (approximately 7 years post-inoculation).
This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. Cattle with the EK211 genotype are oronasally susceptible to small doses of the H-BSE agent from either EK211 or EE211 (wild type) donors. Wild-type EE211 cattle remained asymptomatic for the duration of the experiment with this small dose (0.1g) of inoculum. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=395351
Highlights
This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. Cattle with the EK211 genotype are oronasally susceptible to small doses of the H-BSE agent from either EK211 or EE211 (wild type) donors. Wild-type EE211 cattle remained asymptomatic for the duration of the experiment with this small dose (0.1g) of inoculum. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=395351
Title: A comparison of classical and H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism in wild type and EK211cattle following intracranial inoculation
Author item MOORE, S - Orise Fellow item WEST GREENLEE, M - Iowa State University item Smith, Jodi item Vrentas, Catherine item Nicholson, Eric item Greenlee, Justin
Submitted to: Frontiers in Veterinary Science Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/30/2016 Publication Date: 9/15/2016 Citation: Moore, S.J., West Greenlee, M.H., Smith, J.D., Vrentas, C.E., Nicholson, E.M., Greenlee, J.J. 2016.
A comparison of classical and H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism in wild type and EK211cattle following intracranial inoculation.
Frontiers in Veterinary Science. 3:78. Interpretive
Summary: Cases of bovine spongiform encephalopathy (BSE) or mad cow disease can be subclassified into at least 3 distinct disease forms with the predominate form known as classical BSE and the others collectively referred to as atypical BSE. Atypical BSE can be further subdivided into H-type and L-type cases that are distinct from classical BSE and from each other. Both of the atypical BSE subtypes are believed to occur spontaneously, whereas classical BSE is spread through feeding contaminated meat and bone meal to cattle. Work by other research groups suggests that the stability of the distinguishing features of atypical BSE cases (phenotypical stability) can change to closely resemble classical BSE after experimental passage implicating atypical BSE as a possible origin of classical BSE. Interestingly, one case of H-type BSE in the US was associated with an inherited mutation in the prion protein gene referred to as E211K. The purpose of this work was to compare wild type and cattle with the E211K mutation after experimental inoculation with either classical BSE or H-BSE from the original E211K case. This study demonstrates that the disease features of E211K BSE-H remain stable when transmitted to cattle without the K211 polymorphism. In addition, passage of classical BSE to cattle with the K211 polymorphism results in disease with features consistent with classical BSE and not a switch to atypical BSE-H as a result of the K211 polymorphism. As the origin of classical, feedborne BSE remains unknown and low numbers of atypical BSE are diagnosed each year, parties with interest in the cattle and beef industries and regulatory officials responsible for safe feeding practices of cattle will be interested in this work.
Technical Abstract: In 2006, a case of H-type bovine spongiform encephalopathy (BSE-H) was diagnosed in a cow that was associated with a heritable polymorphism in the bovine prion protein gene (PRNP) resulting in a lysine for glutamine amino acid substitution at codon 211 (called E211K) of the prion protein. Although the prevalence of this polymorphism is low, cattle carrying the K211 allele may be predisposed to rapid onset of BSE-H when exposed or to the potential development of a genetic BSE. This study was conducted to better understand the relationship between the K211 polymorphism and its effect on BSE phenotype. BSE-H from the US 2006 case was inoculated intracranially (IC) in one PRNP wild type (EE211) calf and one EK211 calf. In addition, one wild type calf and one EK211 calf were inoculated IC with brain homogenate from a US 2003 classical BSE case. All cattle developed clinical disease. The survival times of the E211K BSE-H inoculated EK211 calf (10 months) was shorter than the wild type calf (18 months). This genotype effect was not observed in classical BSE inoculated cattle (both 26 months). Significant changes in retinal function were observed in H-type BSE challenged cattle only. Cattle challenged with the same inoculum showed similar severity and neuroanatomical distribution of vacuolation and disease-associated prion protein deposition in the brain, though differences in neuropathology were observed between E211K BSE-H and classical BSE inoculated animals. Western blot results for brain tissue from challenged animals were consistent with the inoculum strains. This study demonstrates that the phenotype of E211K BSE-H remains stable when transmitted to cattle without the K211 polymorphism, and exhibits a number of features that differ from classical BSE in both wild type and heterozygous EK211 animals.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=326785
THURSDAY, JUNE 5, 2025
World Organisation for Animal Health (WOAH) downgrades UK’s BSE risk rating to negligible, what could go wrong?
https://bovineprp.blogspot.com/2025/06/world-organisation-for-animal-health.html
Title: Transmission of atypical BSE: a possible origin of Classical BSE in cattle
Authors: Sandor Dudas1, Samuel James Sharpe1, Kristina Santiago-Mateo1, Stefanie Czub1, Waqas Tahir1,2, * Affiliation: 1National and WOAH reference Laboratory for Bovine Spongiform Encephalopathy, Canadian Food inspection Agency, Lethbridge Laboratory, Lethbridge, Canada. 2Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada. *Corresponding and Presenting Author: waqas.tahir@inspection.gc.ca
Background: Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disease of cattle and is categorized into classical and atypical forms. Classical BSE (CBSE) is linked to the consumption of BSE contaminated feed whereas atypical BSE is considered to be spontaneous in origin. The potential for oral transmission of atypical BSE is yet to be clearly defined.
Aims: To assess the oral transmissibility of atypical BSE (H and L type) in cattle. Should transmission be successful, determine the biochemical characteristics and distribution of PrPSc in the challenge cattle.
Material and Methods: For oral transmission, calves were fed with 100 g of either H (n=3) or L BSE (n=3) positive brain material. Two years post challenge, 1 calf from each of the H and L BSE challenge groups exhibited behavioural signs and were euthanized. Various brain regions of both animals were tested by traditional and novel prion detection methods with inconclusive results. To detect infectivity, brain homogenates from these oral challenge animals (P1) were injected intra-cranially (IC) into steer calves. Upon clinical signs of BSE, 3/4 of IC challenged steer calves were euthanized and tested for PrPSc with ELISA, immunohistochemistry and immunoblot.
Results: After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE.
Conclusion: These results demonstrate the oral transmission potential of atypical BSE in cattle. Surprisingly, regardless of which atypical type of BSE was used for P1 oral challenge, PrPSc in the P2 animals acquired biochemical characteristics similar to that of PrPSc in C-BSE, suggesting atypical BSE as a possible origin of C-BSE in UK.
Presentation Type: Oral Presentation Funded by: CFIA, Health Canada, Alberta Livestock and Meat Agency, Alberta Prion Research Institute
Grant Number: ALMA/APRI: 201400006, HC 414250
Acknowledgement: TSE unit NCAD, Lethbridge (Jianmin Yang, Sarah Bogart, Rachana Muley, Yuanmu Fang, Keri Colwell, Renee Anderson, John Gray, Rakhi Katoch) (CFIA, Canada), Dr. Catherine Graham (NSDA, Canada), Dr. Michel Levy (UCVM, Canada), Dr. Martin Groschup (FLI, Germany), Dr. Christine Fast (FLI, Germany), Dr. Bob Hills (Health Canada, Canada) Theme: Animal prion diseases
"After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE. "
=====end
PRION 2023 CONTINUED;
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Ireland Central Veterinary Research Laboratory confirmed a case of atypical BSE on April 9, 2026
https://bse-atypical.blogspot.com/2026/04/ireland-central-veterinary-research.html
Component 6: Transmissible Spongiform Encephalopathies (TSEs)
Problem Statement 6A: Determine pathobiology of prion strains.
The naturally occurring lysine to glutamic acid substitution (E211K in the bovine prion protein) results in short incubation periods for H-type bovine spongioform encephalopathy (BSE).
Virus and Prion Research Unit, National Animal Disease Center, Ames, Iowa
Classical BSE (C-BSE) is a prion disease of cattle that was responsible for the "mad cow disease" epizootic in Europe in the 1980s. C-BSE was determined to cause the human prion disease vCJD. Since then, atypical spontaneous strains of BSE were identified. H-BSE is one of those strains. Much research has explored the origins of C-BSE, and strain emergence from atypical H-BSE is one hypothesis. An H-BSE case was determined to have a germline mutation, an E211K substitution in the prion protein gene, which is analogous to a hereditary human prion disease. ARS scientists in Ames, Iowa reported the transmission of H-BSE from cattle, with and without the germline prion protein amino acid substitution, to cattle with various prion genotypes: EE211 (wild-type), EK211, and KK211. Results indicated a significantly shorter incubation period in K containing cattle compared to prion wild-type cattle. The scientists also explored the possibility that the C-BSE strain might have occurred after serial passages of EK211 and KK211 containing H-BSE in cattle, but results did not support this concept. This information is important to prion researchers, veterinary diagnostic laboratories, and those involved with establishing regulatory guidelines.
https://www.ars.usda.gov/ARSUserFiles/np103/AnnualReports/Final%20NP103%20FY2024%20Annual%20Report.updated%205.30.25.pdf
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: Cattle with the EK211 PRNP polymorphism are susceptible to the H-type bovine spongiform encephalopathy agent from either E211K or wild type donors after oronasal inoculation
Author item Greenlee, Justin item Cassmann, Eric item MOORE, SARA JO - Oak Ridge Institute For Science And Education (ORISE) item WEST GREENLEE, HEATHER - Iowa State University
Submitted to: Meeting Abstract Publication Type: Abstract Only Publication Acceptance Date: 6/24/2022 Publication Date: 9/16/2022 Citation: Greenlee, J.J., Cassmann, E.D., Moore, S., West Greenlee, H.M. 2022.
Cattle with the EK211 PRNP polymorphism are susceptible to the H-type bovine spongiform encephalopathy agent from either E211K or wild type donors after oronasal inoculation.
Prion 2022 Conference abstracts: pushing the boundaries. 16(1):150. https://doi.org/10.1080/19336896.2022.2091286.
DOI: https://doi.org/10.1080/19336896.2022.2091286
Interpretive Summary:
Technical Abstract: In 2006, a case of H-type bovine spongiform encephalopathy (H-BSE) was reported in a cow with a previously unreported prion protein polymorphism (E211K). The E211K polymorphism is heritable and homologous to the E200K mutation in humans that is the most frequent PRNP mutation associated with familial Creutzfeldt-Jakob disease. Although the prevalence of the E211K polymorphism is low, cattle carrying the K211 allele develop H-type BSE with a rapid onset after experimental inoculation by the intracranial route. The purpose of this study was to investigate whether the agents of H-type BSE or H-type BSE associated with the E211K polymorphism transmit to wild type cattle or cattle with the K211 allele after oronasal exposure. Wild type (EE211) or heterozygous (EK211) cattle were oronasally inoculated with the H-BSE agent from either the US 2004 case (wild type donor; n=3) or from the US 2006 case with the E211K polymorphism (n=4). Cattle were observed daily throughout the course of the experiment for the development of clinical signs. When signs were noted, animals were euthanized and necropsied. Cattle were confirmed positive for abnormal BSE prions by enzyme immunoassay (EIA; Idexx HerdChek BSE Ag Test), anti-PrP immunohistochemistry (IHC) on brainstem, and microscopic examination for vacuolation. Three-out-of-four (75%) calves with the EK211 genotype developed clinical signs of H-BSE including inattentiveness, loss of body condition, weakness, ataxia, and muscle fasciculations and were euthanized. Two of the positive EK211 steers received H-BSE US 2004 inoculum (Incubation Period (IP): 59.3 and 72.3 months) while the other positive steer received the E211K H-BSE inoculum (IP: 49.7 months). EIA confirmed that abundant misfolded protein (O.D. 2.57-4.0) in the brainstem, and IHC demonstrated PrPSc throughout the brain. All cattle in the EE211 recipient group remain asymptomatic for the duration of the experiment (approximately 7 years post-inoculation).
This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. Cattle with the EK211 genotype are oronasally susceptible to small doses of the H-BSE agent from either EK211 or EE211 (wild type) donors. Wild-type EE211 cattle remained asymptomatic for the duration of the experiment with this small dose (0.1g) of inoculum. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=395351
Highlights
This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. Cattle with the EK211 genotype are oronasally susceptible to small doses of the H-BSE agent from either EK211 or EE211 (wild type) donors. Wild-type EE211 cattle remained asymptomatic for the duration of the experiment with this small dose (0.1g) of inoculum. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=395351
Title: A comparison of classical and H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism in wild type and EK211cattle following intracranial inoculation
Author item MOORE, S - Orise Fellow item WEST GREENLEE, M - Iowa State University item Smith, Jodi item Vrentas, Catherine item Nicholson, Eric item Greenlee, Justin
Submitted to: Frontiers in Veterinary Science Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/30/2016 Publication Date: 9/15/2016 Citation: Moore, S.J., West Greenlee, M.H., Smith, J.D., Vrentas, C.E., Nicholson, E.M., Greenlee, J.J. 2016.
A comparison of classical and H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism in wild type and EK211cattle following intracranial inoculation.
Frontiers in Veterinary Science. 3:78. Interpretive
Summary: Cases of bovine spongiform encephalopathy (BSE) or mad cow disease can be subclassified into at least 3 distinct disease forms with the predominate form known as classical BSE and the others collectively referred to as atypical BSE. Atypical BSE can be further subdivided into H-type and L-type cases that are distinct from classical BSE and from each other. Both of the atypical BSE subtypes are believed to occur spontaneously, whereas classical BSE is spread through feeding contaminated meat and bone meal to cattle. Work by other research groups suggests that the stability of the distinguishing features of atypical BSE cases (phenotypical stability) can change to closely resemble classical BSE after experimental passage implicating atypical BSE as a possible origin of classical BSE. Interestingly, one case of H-type BSE in the US was associated with an inherited mutation in the prion protein gene referred to as E211K. The purpose of this work was to compare wild type and cattle with the E211K mutation after experimental inoculation with either classical BSE or H-BSE from the original E211K case. This study demonstrates that the disease features of E211K BSE-H remain stable when transmitted to cattle without the K211 polymorphism. In addition, passage of classical BSE to cattle with the K211 polymorphism results in disease with features consistent with classical BSE and not a switch to atypical BSE-H as a result of the K211 polymorphism. As the origin of classical, feedborne BSE remains unknown and low numbers of atypical BSE are diagnosed each year, parties with interest in the cattle and beef industries and regulatory officials responsible for safe feeding practices of cattle will be interested in this work.
Technical Abstract: In 2006, a case of H-type bovine spongiform encephalopathy (BSE-H) was diagnosed in a cow that was associated with a heritable polymorphism in the bovine prion protein gene (PRNP) resulting in a lysine for glutamine amino acid substitution at codon 211 (called E211K) of the prion protein. Although the prevalence of this polymorphism is low, cattle carrying the K211 allele may be predisposed to rapid onset of BSE-H when exposed or to the potential development of a genetic BSE. This study was conducted to better understand the relationship between the K211 polymorphism and its effect on BSE phenotype. BSE-H from the US 2006 case was inoculated intracranially (IC) in one PRNP wild type (EE211) calf and one EK211 calf. In addition, one wild type calf and one EK211 calf were inoculated IC with brain homogenate from a US 2003 classical BSE case. All cattle developed clinical disease. The survival times of the E211K BSE-H inoculated EK211 calf (10 months) was shorter than the wild type calf (18 months). This genotype effect was not observed in classical BSE inoculated cattle (both 26 months). Significant changes in retinal function were observed in H-type BSE challenged cattle only. Cattle challenged with the same inoculum showed similar severity and neuroanatomical distribution of vacuolation and disease-associated prion protein deposition in the brain, though differences in neuropathology were observed between E211K BSE-H and classical BSE inoculated animals. Western blot results for brain tissue from challenged animals were consistent with the inoculum strains. This study demonstrates that the phenotype of E211K BSE-H remains stable when transmitted to cattle without the K211 polymorphism, and exhibits a number of features that differ from classical BSE in both wild type and heterozygous EK211 animals.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=326785
THURSDAY, JUNE 5, 2025
World Organisation for Animal Health (WOAH) downgrades UK’s BSE risk rating to negligible, what could go wrong?
https://bovineprp.blogspot.com/2025/06/world-organisation-for-animal-health.html
Title: Transmission of atypical BSE: a possible origin of Classical BSE in cattle
Authors: Sandor Dudas1, Samuel James Sharpe1, Kristina Santiago-Mateo1, Stefanie Czub1, Waqas Tahir1,2, * Affiliation: 1National and WOAH reference Laboratory for Bovine Spongiform Encephalopathy, Canadian Food inspection Agency, Lethbridge Laboratory, Lethbridge, Canada. 2Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada. *Corresponding and Presenting Author: waqas.tahir@inspection.gc.ca
Background: Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disease of cattle and is categorized into classical and atypical forms. Classical BSE (CBSE) is linked to the consumption of BSE contaminated feed whereas atypical BSE is considered to be spontaneous in origin. The potential for oral transmission of atypical BSE is yet to be clearly defined.
Aims: To assess the oral transmissibility of atypical BSE (H and L type) in cattle. Should transmission be successful, determine the biochemical characteristics and distribution of PrPSc in the challenge cattle.
Material and Methods: For oral transmission, calves were fed with 100 g of either H (n=3) or L BSE (n=3) positive brain material. Two years post challenge, 1 calf from each of the H and L BSE challenge groups exhibited behavioural signs and were euthanized. Various brain regions of both animals were tested by traditional and novel prion detection methods with inconclusive results. To detect infectivity, brain homogenates from these oral challenge animals (P1) were injected intra-cranially (IC) into steer calves. Upon clinical signs of BSE, 3/4 of IC challenged steer calves were euthanized and tested for PrPSc with ELISA, immunohistochemistry and immunoblot.
Results: After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE.
Conclusion: These results demonstrate the oral transmission potential of atypical BSE in cattle. Surprisingly, regardless of which atypical type of BSE was used for P1 oral challenge, PrPSc in the P2 animals acquired biochemical characteristics similar to that of PrPSc in C-BSE, suggesting atypical BSE as a possible origin of C-BSE in UK.
Presentation Type: Oral Presentation Funded by: CFIA, Health Canada, Alberta Livestock and Meat Agency, Alberta Prion Research Institute
Grant Number: ALMA/APRI: 201400006, HC 414250
Acknowledgement: TSE unit NCAD, Lethbridge (Jianmin Yang, Sarah Bogart, Rachana Muley, Yuanmu Fang, Keri Colwell, Renee Anderson, John Gray, Rakhi Katoch) (CFIA, Canada), Dr. Catherine Graham (NSDA, Canada), Dr. Michel Levy (UCVM, Canada), Dr. Martin Groschup (FLI, Germany), Dr. Christine Fast (FLI, Germany), Dr. Bob Hills (Health Canada, Canada) Theme: Animal prion diseases
"After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE. "
=====end
PRION 2023 CONTINUED;
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Ireland Central Veterinary Research Laboratory confirmed a case of atypical BSE on April 9, 2026
https://bse-atypical.blogspot.com/2026/04/ireland-central-veterinary-research.html
Chronic Wasting Disease CWD TSE Prion Cervid
cwd transmits by oral routes to, cattle, pigs, sheep, primates
cwd to cattle
Prion Conference 2023
Transmission of the chronic wasting disease agent from elk to cattle after oronasal exposure
Conclusions: Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material.
Strain characterization of chronic wasting disease in bovine-PrP transgenic mice
Conclusions: Altogether, these results exhibit the diversity of CWD strains present in the panel of CWD isolates and the ability of at least some CWD isolates to infect bovine species. Cattle being one of the most important farming species, this ability represents a potential threat to both animal and human health, and consequently deserves further study.
Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
cwd to pigs
WEDNESDAY, JANUARY 28, 2026
Chronic wasting disease prions in cervids and wild pigs in North America Preliminary Outbreak
https://journals.asm.org/doi/10.1128/mbio.01800-25
https://wwwnc.cdc.gov/eid/article/31/1/24-0401_article
https://transmissiblespongiformencephalopathy.blogspot.com/2026/01/chronic-wasting-disease-prions-in.html
cwd to sheep
Chronic Wasting Disease CWD vs Scrapie TSE Prion
https://www.ars.usda.gov/research/publications/publication/?seqNo115=410511
Detection of infectivity in orally inoculated pigs using mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity. Currently, swine rations in the U.S. could contain animal derived components including materials from deer or elk. In addition, feral swine could be exposed to infected carcasses in areas where CWD is present in wildlife populations. The current feed ban in the U.S. is based exclusively on keeping tissues from TSE infected cattle from entering animal feeds. These results indicating the susceptibility of pigs to CWD, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=353091
https://www.ars.usda.gov/research/project/?accnNo=432011&fy=2017
https://www.ars.usda.gov/research/publications/publication/?seqNo115=337105
https://www.ars.usda.gov/research/publications/publication/?seqNo115=326166
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
Title: Differentiation of scrapie from chronic wasting disease in white-tailed deer
Accomplishments
1. 01 Determined that white-tailed deer (WTD) infected with scrapie from sheep can transmit the disease to other deer under conditions mimicking natural exposure. It has long been suggested that prion disease in deer (chronic wasting disease (CWD)) was caused by the prion agent from sheep. The prion disease that affects sheep, scrapie, has been recognized for hundreds of years. However, chronic wasting disease, a similar disease found in WTD, has only been recognized since the 1960s. ARS researchers in Ames, Iowa, showed that white-tailed deer sick with scrapie from sheep can infect other deer under conditions mimicking natural exposure. Furthermore, this work shows that CWD is difficult to differentiate from WTD infected with scrapie. WTD scrapie prions accumulate in the lymphoreticular system in a manner similar to CWD, meaning that environmental contamination may occur through feces, saliva, and other body fluids of scrapie affected WTD as has been shown for CWD. The presence of WTD infected with scrapie could confound mitigation efforts for chronic wasting disease. This information informs regulatory officials, the farmed cervid industry, and officials tasked with protecting animal health such as state Departments of Agriculture, Natural Resources, or Parks and Wildlife with regard to a disease similar to CWD but arising from sheep scrapie that could be present in WTD that have contact with scrapie affected sheep and/or goats.
https://www.ars.usda.gov/research/project/?accnNo=440677&fy=202
Chronic Wasting Disease CWD vs Scrapie TSE Prion
Volume 30, Number 8—August 2024
Research
Scrapie Versus Chronic Wasting Disease in White-Tailed Deer
Zoe J. Lambert1, Jifeng Bian, Eric D. Cassmann, M. Heather West Greenlee, and Justin J. Greenlee
Author affiliations: Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA (Z.J. Lambert); US Department of Agriculture, Ames, Iowa, USA (Z.J. Lambert, J. Bian, E.D. Cassmann, J.J. Greenlee); Iowa State University, Ames (Z.J. Lambert, M.H. West Greenlee) Suggested citation for this article
Abstract
White-tailed deer are susceptible to scrapie (WTD scrapie) after oronasal inoculation with the classical scrapie agent from sheep. Deer affected by WTD scrapie are difficult to differentiate from deer infected with chronic wasting disease (CWD). To assess the transmissibility of the WTD scrapie agent and tissue phenotypes when further passaged in white-tailed deer, we oronasally inoculated wild-type white-tailed deer with WTD scrapie agent. We found that WTD scrapie and CWD agents were generally similar, although some differences were noted. The greatest differences were seen in bioassays of cervidized mice that exhibited significantly longer survival periods when inoculated with WTD scrapie agent than those inoculated with CWD agent. Our findings establish that white-tailed deer are susceptible to WTD scrapie and that the presence of WTD scrapie agent in the lymphoreticular system suggests the handling of suspected cases should be consistent with current CWD guidelines because environmental shedding may occur.
snip…
The potential for zoonoses of cervid-derived PrPSc is still not well understood (6,18,45–47); however, interspecies transmission can increase host range and zoonotic potential (48–50). Therefore, to protect herds and the food supply, suspected cases of WTD scrapie should be handled the same as cases of CWD.
https://wwwnc.cdc.gov/eid/article/30/8/24-0007_article
Western blots done on samples from the brainstem, cerebellum, and lymph nodes of scrapie-infected WTD have a molecular profile similar to CWD and distinct from western blots of samples from the cerebral cortex, retina, or the original sheep scrapie inoculum. WTD are susceptible to the agent of scrapie from sheep and differentiation from CWD may be difficult.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=336834
It has long been hypothesized that CWD arose through transmission of sheep scrapie to deer. ARS researchers in Ames, Iowa, conducted research to determine if scrapie derived from sheep could be transmitted to white-tailed deer. The deer inoculated with sheep scrapie developed clinical signs and the abnormal prion protein could be detected in a wide range of tissues. These results indicate that deer may be susceptible to sheep scrapie if exposed to the disease in natural or agricultural settings. In addition, several strong similarities between CWD in white-tailed deer and the experimental cases of scrapie in white-tailed deer suggests that it would be difficult to distinguish scrapie from CWD in deer or identify scrapie if a case occurs. This information should be considered by deer farmers for keeping their herds free from prion diseases.
https://www.ars.usda.gov/ARSUserFiles/np103/AnnualReports/NP103%20FY2023%20Annual%20Report_Final.pdf
Additional studies in WTD established a minimum oral CWD infectious dose equivalent to 100–300 ng CWD-positive brain tissue (10)…
We report that oral exposure to as little as 300 nanograms (ng) of CWD-positive brain or to saliva containing seeding activity equivalent to 300 ng of CWD-positive brain, were sufficient to transmit CWD disease.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237410
ORIGIN OF CHRONIC WASTING DISEASE TSE PRION?COLORADO THE ORIGIN OF CHRONIC WASTING DISEASE CWD TSE PRION?
*** Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.
IN CONFIDENCE, REPORT OF AN UNCONVENTIONAL SLOW VIRUS DISEASE IN ANIMALS IN THE USA 1989
http://webarchive.nationalarchives.gov.uk/20080102193705/http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf
The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite its subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA viewed it as a wildlife problem and consequently not their province!” page 26.
https://web.archive.org/web/20060307063531/http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf
The chronic wasting disease agent from white-tailed deer is highly infectious to humanized mice after passage through raccoons
https://www.ars.usda.gov/research/publications/publication/?seqNo115=400777
cwd to cattle
Prion Conference 2023
Transmission of the chronic wasting disease agent from elk to cattle after oronasal exposure
Conclusions: Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material.
Strain characterization of chronic wasting disease in bovine-PrP transgenic mice
Conclusions: Altogether, these results exhibit the diversity of CWD strains present in the panel of CWD isolates and the ability of at least some CWD isolates to infect bovine species. Cattle being one of the most important farming species, this ability represents a potential threat to both animal and human health, and consequently deserves further study.
Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
cwd to pigs
WEDNESDAY, JANUARY 28, 2026
Chronic wasting disease prions in cervids and wild pigs in North America Preliminary Outbreak
https://journals.asm.org/doi/10.1128/mbio.01800-25
https://wwwnc.cdc.gov/eid/article/31/1/24-0401_article
https://transmissiblespongiformencephalopathy.blogspot.com/2026/01/chronic-wasting-disease-prions-in.html
cwd to sheep
Chronic Wasting Disease CWD vs Scrapie TSE Prion
https://www.ars.usda.gov/research/publications/publication/?seqNo115=410511
Detection of infectivity in orally inoculated pigs using mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity. Currently, swine rations in the U.S. could contain animal derived components including materials from deer or elk. In addition, feral swine could be exposed to infected carcasses in areas where CWD is present in wildlife populations. The current feed ban in the U.S. is based exclusively on keeping tissues from TSE infected cattle from entering animal feeds. These results indicating the susceptibility of pigs to CWD, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=353091
https://www.ars.usda.gov/research/project/?accnNo=432011&fy=2017
https://www.ars.usda.gov/research/publications/publication/?seqNo115=337105
https://www.ars.usda.gov/research/publications/publication/?seqNo115=326166
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
Title: Differentiation of scrapie from chronic wasting disease in white-tailed deer
Accomplishments
1. 01 Determined that white-tailed deer (WTD) infected with scrapie from sheep can transmit the disease to other deer under conditions mimicking natural exposure. It has long been suggested that prion disease in deer (chronic wasting disease (CWD)) was caused by the prion agent from sheep. The prion disease that affects sheep, scrapie, has been recognized for hundreds of years. However, chronic wasting disease, a similar disease found in WTD, has only been recognized since the 1960s. ARS researchers in Ames, Iowa, showed that white-tailed deer sick with scrapie from sheep can infect other deer under conditions mimicking natural exposure. Furthermore, this work shows that CWD is difficult to differentiate from WTD infected with scrapie. WTD scrapie prions accumulate in the lymphoreticular system in a manner similar to CWD, meaning that environmental contamination may occur through feces, saliva, and other body fluids of scrapie affected WTD as has been shown for CWD. The presence of WTD infected with scrapie could confound mitigation efforts for chronic wasting disease. This information informs regulatory officials, the farmed cervid industry, and officials tasked with protecting animal health such as state Departments of Agriculture, Natural Resources, or Parks and Wildlife with regard to a disease similar to CWD but arising from sheep scrapie that could be present in WTD that have contact with scrapie affected sheep and/or goats.
https://www.ars.usda.gov/research/project/?accnNo=440677&fy=202
Chronic Wasting Disease CWD vs Scrapie TSE Prion
Volume 30, Number 8—August 2024
Research
Scrapie Versus Chronic Wasting Disease in White-Tailed Deer
Zoe J. Lambert1, Jifeng Bian, Eric D. Cassmann, M. Heather West Greenlee, and Justin J. Greenlee
Author affiliations: Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA (Z.J. Lambert); US Department of Agriculture, Ames, Iowa, USA (Z.J. Lambert, J. Bian, E.D. Cassmann, J.J. Greenlee); Iowa State University, Ames (Z.J. Lambert, M.H. West Greenlee) Suggested citation for this article
Abstract
White-tailed deer are susceptible to scrapie (WTD scrapie) after oronasal inoculation with the classical scrapie agent from sheep. Deer affected by WTD scrapie are difficult to differentiate from deer infected with chronic wasting disease (CWD). To assess the transmissibility of the WTD scrapie agent and tissue phenotypes when further passaged in white-tailed deer, we oronasally inoculated wild-type white-tailed deer with WTD scrapie agent. We found that WTD scrapie and CWD agents were generally similar, although some differences were noted. The greatest differences were seen in bioassays of cervidized mice that exhibited significantly longer survival periods when inoculated with WTD scrapie agent than those inoculated with CWD agent. Our findings establish that white-tailed deer are susceptible to WTD scrapie and that the presence of WTD scrapie agent in the lymphoreticular system suggests the handling of suspected cases should be consistent with current CWD guidelines because environmental shedding may occur.
snip…
The potential for zoonoses of cervid-derived PrPSc is still not well understood (6,18,45–47); however, interspecies transmission can increase host range and zoonotic potential (48–50). Therefore, to protect herds and the food supply, suspected cases of WTD scrapie should be handled the same as cases of CWD.
https://wwwnc.cdc.gov/eid/article/30/8/24-0007_article
Western blots done on samples from the brainstem, cerebellum, and lymph nodes of scrapie-infected WTD have a molecular profile similar to CWD and distinct from western blots of samples from the cerebral cortex, retina, or the original sheep scrapie inoculum. WTD are susceptible to the agent of scrapie from sheep and differentiation from CWD may be difficult.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=336834
It has long been hypothesized that CWD arose through transmission of sheep scrapie to deer. ARS researchers in Ames, Iowa, conducted research to determine if scrapie derived from sheep could be transmitted to white-tailed deer. The deer inoculated with sheep scrapie developed clinical signs and the abnormal prion protein could be detected in a wide range of tissues. These results indicate that deer may be susceptible to sheep scrapie if exposed to the disease in natural or agricultural settings. In addition, several strong similarities between CWD in white-tailed deer and the experimental cases of scrapie in white-tailed deer suggests that it would be difficult to distinguish scrapie from CWD in deer or identify scrapie if a case occurs. This information should be considered by deer farmers for keeping their herds free from prion diseases.
https://www.ars.usda.gov/ARSUserFiles/np103/AnnualReports/NP103%20FY2023%20Annual%20Report_Final.pdf
Additional studies in WTD established a minimum oral CWD infectious dose equivalent to 100–300 ng CWD-positive brain tissue (10)…
We report that oral exposure to as little as 300 nanograms (ng) of CWD-positive brain or to saliva containing seeding activity equivalent to 300 ng of CWD-positive brain, were sufficient to transmit CWD disease.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237410
ORIGIN OF CHRONIC WASTING DISEASE TSE PRION?COLORADO THE ORIGIN OF CHRONIC WASTING DISEASE CWD TSE PRION?
*** Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.
IN CONFIDENCE, REPORT OF AN UNCONVENTIONAL SLOW VIRUS DISEASE IN ANIMALS IN THE USA 1989
http://webarchive.nationalarchives.gov.uk/20080102193705/http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf
The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite its subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA viewed it as a wildlife problem and consequently not their province!” page 26.
https://web.archive.org/web/20060307063531/http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf
The chronic wasting disease agent from white-tailed deer is highly infectious to humanized mice after passage through raccoons
https://www.ars.usda.gov/research/publications/publication/?seqNo115=400777
USA Report, Scrapie, CWD, BSE, TSE, Cattle, Sheep, Pigs, Cervid, Humans, Zoonotic, 2026
USA FDA PART 589 SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEED, CWD, Scrapie, BSE, Oh My, 2026
https://prpsc.proboards.com/thread/202/usa-fda-589-feed-broken
https://madcowfeed.blogspot.com/2026/01/usa-fda-part-589-substances-prohibited.html
SATURDAY, APRIL 11, 2026
Chronic Wasting Disease CWD TSE PrP, Cervid, Genetic Manipulation, Unforeseen Circumstances
https://chronic-wasting-disease.blogspot.com/2026/04/chronic-wasting-disease-cwd-tse-prp.html
TUESDAY, APRIL 07, 2026
APHIS USDA Captive CWD Herds Update by State March 2026
https://chronic-wasting-disease.blogspot.com/2026/04/aphis-usda-captive-cwd-herds-update-by.html
April 2026
https://prpsc.proboards.com/thread/202/usa-fda-589-feed-broken
https://madcowfeed.blogspot.com/2026/01/usa-fda-part-589-substances-prohibited.html
SATURDAY, APRIL 11, 2026
Chronic Wasting Disease CWD TSE PrP, Cervid, Genetic Manipulation, Unforeseen Circumstances
https://chronic-wasting-disease.blogspot.com/2026/04/chronic-wasting-disease-cwd-tse-prp.html
TUESDAY, APRIL 07, 2026
APHIS USDA Captive CWD Herds Update by State March 2026
https://chronic-wasting-disease.blogspot.com/2026/04/aphis-usda-captive-cwd-herds-update-by.html
Scrapie, CWD, BSE, CJD, TSE, PrP Update 2026
***> CWD Action Plan National Program 103 Animal Health 2022-2027 UPDATE JANUARY 2026
https://prpsc.proboards.com/thread/189/action-national-program-animal-health
https://chronic-wasting-disease.blogspot.com/2026/01/cwd-action-plan-national-program-103.html
***> SCRAPIE TSE Prion USA RAPID RESPONSE URGENT UPDATES DECEMBER 25, 2025
***> CWD vs Scrapie Urgent Update
https://scrapie-usa.blogspot.com/2025/12/scrapie-tse-prion-usa-rapid-response.html
https://prpsc.proboards.com/thread/186/scrapie-prion-response-urgent-updates
***> 2026 USDA EXPLANATORY NOTES, APHIS, CWD, BSE, Scrapie, TSE, Prion
https://transmissiblespongiformencephalopathy.blogspot.com/2025/12/2026-usda-explanatory-notes-aphis-cwd.html
USDA National Scrapie Program History and Bovine Spongiform Encephalopathy BSE TSE Update 2025 and history there from
https://www.researchgate.net/publication/396084947_USDA_National_Scrapie_Program_History_and_Bovine_Spongiform_Encephalopathy_BSE_TSE0AUpdate_2
TUESDAY, JANUARY 20, 2026
Pathogenesis, Transmission and Detection of Zoonotic Prion Diseases Project Number 5P01AI077774-14 2025
https://chronic-wasting-disease.blogspot.com/2026/01/pathogenesis-transmission-and-detection.html
TUESDAY, SEPTEMBER 30, 2025
USDA National Scrapie Program History and Bovine Spongiform Encephalopathy BSE TSE Update 2025
https://bovineprp.blogspot.com/2025/09/usda-national-scrapie-program-history.html
https://scrapie-usa.blogspot.com/2025/09/usda-national-scrapie-program-history.html
Cattle with the E211K polymorphism, and gCJD linked to a glutamic acid to lysine substitution at codon 200 (E200K) of PRNP, what if?
https://creutzfeldt-jakob-disease.blogspot.com/2026/01/cattle-with-e211k-polymorphism-and-gcjd.html
Cattle with the E211K vs Humans E200K of PRNP, what if?
https://prpsc.proboards.com/thread/195/cattle-e211k-humans-e200k-prnp
***> CWD Action Plan National Program 103 Animal Health 2022-2027 UPDATE JANUARY 2026
https://prpsc.proboards.com/thread/189/action-national-program-animal-health
https://chronic-wasting-disease.blogspot.com/2026/01/cwd-action-plan-national-program-103.html
***> SCRAPIE TSE Prion USA RAPID RESPONSE URGENT UPDATES DECEMBER 25, 2025
***> CWD vs Scrapie Urgent Update
https://scrapie-usa.blogspot.com/2025/12/scrapie-tse-prion-usa-rapid-response.html
https://prpsc.proboards.com/thread/186/scrapie-prion-response-urgent-updates
***> 2026 USDA EXPLANATORY NOTES, APHIS, CWD, BSE, Scrapie, TSE, Prion
https://transmissiblespongiformencephalopathy.blogspot.com/2025/12/2026-usda-explanatory-notes-aphis-cwd.html
USDA National Scrapie Program History and Bovine Spongiform Encephalopathy BSE TSE Update 2025 and history there from
https://www.researchgate.net/publication/396084947_USDA_National_Scrapie_Program_History_and_Bovine_Spongiform_Encephalopathy_BSE_TSE0AUpdate_2
TUESDAY, JANUARY 20, 2026
Pathogenesis, Transmission and Detection of Zoonotic Prion Diseases Project Number 5P01AI077774-14 2025
https://chronic-wasting-disease.blogspot.com/2026/01/pathogenesis-transmission-and-detection.html
TUESDAY, SEPTEMBER 30, 2025
USDA National Scrapie Program History and Bovine Spongiform Encephalopathy BSE TSE Update 2025
https://bovineprp.blogspot.com/2025/09/usda-national-scrapie-program-history.html
https://scrapie-usa.blogspot.com/2025/09/usda-national-scrapie-program-history.html
Cattle with the E211K polymorphism, and gCJD linked to a glutamic acid to lysine substitution at codon 200 (E200K) of PRNP, what if?
https://creutzfeldt-jakob-disease.blogspot.com/2026/01/cattle-with-e211k-polymorphism-and-gcjd.html
Cattle with the E211K vs Humans E200K of PRNP, what if?
https://prpsc.proboards.com/thread/195/cattle-e211k-humans-e200k-prnp
US Report, Scrapie, CWD, Cattle, Sheep, Pigs, Cervid, Humans, Zoonotic, 2026
SUNDAY, APRIL 12, 2026
Chronic Wasting Disease in Farmed Cervids, South Korea, 2001–2024
https://chronic-wasting-disease.blogspot.com/2026/04/chronic-wasting-disease-in-farmed.html
Chronic Wasting Disease in Farmed Cervids, South Korea, 2001–2024
https://chronic-wasting-disease.blogspot.com/2026/04/chronic-wasting-disease-in-farmed.html
Wednesday, April 1, 2026
First identification of camel prion disease in Tataouine, Tunisia: an emerging animal prion disease in North Africa
https://camelusprp.blogspot.com/2026/04/first-identification-of-camel-prion.html
SUNDAY, MARCH 8, 2026
Texas Creutzfeldt-Jakob Disease Deaths and Death Rates per Year (2013-2022) More Than Tripled, and case reporting has ceased since then
https://cjdtexas.blogspot.com/2026/03/texas-creutzfeldt-jakob-disease-deaths.html
https://prpsc.proboards.com/thread/209/texas-cases-more-triples-2013
WEDNESDAY, OCTOBER 15, 2025
US NATIONAL PRION DISEASE PATHOLOGY SURVEILLANCE CENTER CJD TSE REPORT 2025
https://prionunitusaupdate.blogspot.com/2025/10/us-national-prion-disease-pathology.html
FRIDAY, NOVEMBER 21, 2025
While no one was watching: Tenuous status of CDC prion unit, risk of CWD to people worry scientists
https://chronic-wasting-disease.blogspot.com/2025/11/while-no-one-was-watching-tenuous.html
SATURDAY, JANUARY 10, 2026
Neuropsychiatric symptoms in sporadic Creutzfeldt-Jakob disease, a review
https://creutzfeldt-jakob-disease.blogspot.com/2026/01/neuropsychiatric-symptoms-in-sporadic.html
https://prpsc.proboards.com/thread/191/neuropsychiatric-symptoms-sporadic-cjd-review
SUNDAY, MARCH 23, 2025
Creutzfeldt Jakob Disease TSE Prion Increasing 2025 Update
https://creutzfeldt-jakob-disease.blogspot.com/2025/03/creutzfeldt-jakob-disease-tse-prion.html
FRIDAY, DECEMBER 13, 2024
Creutzfeldt Jacob Disease CJD, BSE, CWD, TSE Prion, December 14, 2024 Annual Update
https://creutzfeldt-jakob-disease.blogspot.com/2024/12/creutzfeldt-jacob-disease-cjd-bse-cwd.html
Friendly Fire, unforeseen circumstances, iatrogenic Transmissible Spongiform Encephalopathy
The Eyes are the windows to Our Souls, and a Potential Pathway for the TSE Prion disease, what if?
Terry S. Singeltary Sr. Bacliff, Texas 77518 flounder9@verizon.net
