Redefining the zoonotic potential of chronic wasting disease Singeltary Review
Redefining the zoonotic potential of chronic wasting disease Singeltary Review
Redefining the zoonotic potential of chronic wasting disease
Project Number 5R01NS121016-04
Contact PI/Project Leader SCHATZL, HERMANN M
Other PIs
Awardee Organization
UNIVERSITY OF CALGARY
Description
Abstract Text
The rapid expansion of chronic wasting disease (CWD), a prion disease of free-ranging and farmed deer, elk and moose, is a major and ongoing threat in North America. Approximately 1 in 36 Americans hunt deer and elk and eat venison, and it is estimated that 7,000 – 15,000 CWD-infected cervids are consumed annually. This fuels growing concerns about the human health risks imposed by CWD. There are no documented cases of CWD transmission to humans, even though with the long incubation periods of all prion diseases and the unknown presentation of CWD in humans definite conclusions are not possible. The zoonotic potential of prion diseases has been exemplified by bovine spongiform encephalopathy (BSE, mad cow disease) which resulted in a new form of human prion disease (vCJD). BSE was transmissible to Cynomolgus macaques and transgenic mice expressing the human prion protein. Initial results of CWD transmission studies to the same non-human primate and mouse models of human prion disease were not successful, corroborating the conclusion that the zoonotic potential of CWD is low, if not absent. Our groups were part of a consortium that inoculated Cynomolgus macaques via different routes with CWD. Some animals exhibited subtle clinical signs reminiscent of prion disease, and upon euthanasia, weak signs of vacuolation, PrPSc deposition and astrocytosis in the brain were found, while no proteinase K (PK) resistant prion protein (PrP) was detectable. We have now demonstrated for the first time that CWD from macaques can transmit clinical prion disease to transgenic mouse models of CWD and human prion disease, albeit in the absence of detectable PK-resistant PrP. Bona fide PrPSc was only detected upon 3rd passage from mouse to bank vole models. Altogether, this is the first evidence that CWD very likely has zoonotic potential. The goal of the current proposal is to redefine the zoonotic potential of CWD by characterizing the biological properties of CWD prions emerging upon experimental transmission into macaques, for obtaining important information on how CWD could manifest in humans.
In Aim 1, we will study whether CWD from macaque (CWDmac) in bank voles represents a new prion strain, by comparing biochemical and biological properties to an array of known prion strains from different species.
Aim 2 addresses the question whether CWDmac represents an intermediate prion strain, adaptable to cervids or humans upon passage, and possessing an expanded host range. We will address this by in vivo passage in cervidized or humanized mouse models. In vitro, we will utilize serial PMCA and a newly generated PrP0/0 cell culture model for infection, upon reconstitution with PrP from different species.
In Aim 3, we will shed light on the observed dissociation between infectivity and the presence of bona fide PrPSc. We propose to identify atypical PrP fragments associated with CWDmac, and we will elucidate brain cell responses to CWDmac exposure by innovative single cell RNA sequencing. In summary, our studies will uncover the possible manifestation of CWD in humans, which is of critical importance for drawing definite conclusions about the zoonotic potential of CWD.
Public Health Relevance Statement
The zoonotic potential of chronic wasting disease (CWD) is unclear to date. We provide the first evidence by transmission experiments to different transgenic mouse models and bank voles that Cynomolgus macaques inoculated via different routes with CWD-positive cervid tissues harbor infectious prions that elicit clinical disease in rodents. Our proposed studies will unravel the properties of these prions, how they will adapt to humans and which pathways are activated in brain cells and associated with clinical disease. Results from these studies uncover the potential manifestation of CWD in humans, which is highly relevant for human health.
https://eventos.galoa.com.br/prion-2025/page/5178-home
Project 3A: CWD Prion Shedding and Environmental Contamination: Role in Transmission and Zoonotic
Parent Project Number 5P01AI077774-14
Sub-Project ID 5512
Contact PI/Project Leader HOOVER, EDWARD ARTHUR
Awardee Organization UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
Description
Abstract Text
Chronic wasting disease (CWD) is an emergent, highly transmissible, geographically expanding, prion disease of both wild and captive cervids. CWD is unique among prion diseases in its facile contagion and environmental persistence. Its expanding geographical range, combined with the increasing transport of animals and animal products, portend its continued expansion and diversification. The zoonotic potential of CWD remains poorly understood. CWD endemic areas interface cervids with livestock species and humans, posing obvious zoonotic risks that over time will increase. While it is known that strains of CWD exist, nothing is known about the zoonotic potential of these strains. Work from our applicant group has shown that CWD infected cervids continually shed prions into the environment and that previously unrecognized environmental factors can influence the emergence of a dominant strain from a mixture. The ability to recognize the zoonotic potential of CWD strains is central to mitigating CWD transmission risk. The central hypothesis for work described here is that CWD strains evolve continuously due to a combination of both host and environmental factors. We will test this hypothesis by:
i) determining the evolution and zoonotic impact of CWD strains in the native cervid species;
ii) leveraging our unique animal resources, expertise, and in vivo & in vitro methodologies to assess environmental factors that alter CWD strain selection and evolution and
iii) evaluate zoonotic potential of CWD strains by a complementary combination of in vitro amplification assays and animal transmission studies.
The results will provide new information about this emergent transmissible prion disease and the risk it poses to humans and other species.
https://reporter.nih.gov/project-details/11056111#description
Project 3B: Pathogenesis Transmission and Detection of Zoonotic Prion Diseases
Parent Project Number 5P01AI077774-14
Sub-Project ID 5513
Contact PI/Project Leader BARTZ, JASON C
Awardee Organization UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
Description Abstract Text
Project Summary: Chronic wasting disease (CWD) is an emergent, highly transmissible, geographically expanding, prion disease of both wild and captive cervids. CWD is unique among prion diseases in its facile contagion and environmental persistence. Its expanding geographical range, combined with the increasing transport of animals and animal products, portend its continued expansion and diversification. The zoonotic potential of CWD remains poorly understood. CWD endemic areas interface cervids with livestock species and humans, posing obvious zoonotic risks that over time will increase. While it is known that strains of CWD exist, nothing is known about the zoonotic potential of these strains. Work from our applicant group has shown that CWD- infected cervids continually shed prions into the environment and that previously unrecognized environmental factors can influence the emergence of a dominant strain from a mixture. The ability to recognize the zoonotic potential of CWD strains is central to mitigating CWD transmission risk. The central hypothesis for work described here is that CWD strains evolve continuously due to a combination of both host and environmental factors. We will test this hypothesis by:
i) determining the evolution and zoonotic impact of CWD strains in the native cervid species;
ii) leveraging our unique animal resources, expertise, and in vivo & in vitro methodologies to assess environmental factors that alter CWD strain selection and evolution and
iii) evaluate zoonotic potential of CWD strains by a complementary combination of in vitro amplification assays and animal transmission studies.
The results will provide new information about this emergent transmissible prion disease and the risk it poses to humans and other species.
https://reporter.nih.gov/project-details/11056115#description
Project 1: Modeling the Mechanisms of Prion Transmission, Strain Selection, Mutation and Species Barrier in Transgenic Mice
Parent Project Number 5P01AI077774-14
Sub-Project ID 5510
Contact PI/Project Leader TELLING, GLENN C
Awardee Organization UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
Description Abstract Text
Our broad, long-term objectives are to are to decipher the mechanisms by which infectious prions replicate, encode strain information, and evolve to acquire new properties. We propose four Specific Aims to address our central hypothesis that incompletely adapted prion strains are comprised of poorly optimized ensembles of PrPSc quasi species conformers that evolve under selective pressure towards states of enhanced stability and pathogenicity. Our particular focus is chronic wasting disease (CWD), an uncontrollable contagious epidemic of cervids of uncertain zoonotic potential. Using genetically engineered CWD-susceptible mice, cultured cells, cell free amplification, and antibodies recognizing defined conformation-dependent PrP epitopes,
Aim I will address the mechanism of adaptation of unstable emergent CWD prions in response to physical and chemical constraints.
In Aim II we will address the hypothesis that that residue 226 and other cervid PrP polymorphisms influence selection of distinct portfolios of CWD strain conformers with different adaptive potentials. Using gene targeted mice expressing physiologically controlled levels of PrP variants and in vitro systems for prion replication, we will characterize the properties of strains propagated in these backgrounds and explore whether interference between them affects selection and adaptation of CWD.
In Aim III, we will assess the properties of emergent Norwegian moose and reindeer CWD strains experimentally propagated in deer and compare with established North American CWD.
Aim IV will address an unmet need in the field of significant importance, namely the paucity of model systems and tools for studying human prions. Using newly generated gene targeted mice expressing physiological levels of human PrP and novel approaches to derive susceptible human neuroblastoma cells, we will assess the zoonotic potential of emergent CWD strains and their adapted derivatives propagated in different cervid PrP backgrounds. Our ultimate goal is to assess and manage the risk posed to humans from continually evolving prions, specifically those causing CWD, by understanding the means by which they propagate and exist as heritable strains with protean host range properties that adapt and evolve under selective pressure.
https://reporter.nih.gov/project-details/11056096#description
Project 2
Parent Project Number 5P01AI077774-14
Sub-Project ID 5511
Contact PI/Project Leader SOTO, CLAUDIO
Awardee Organization UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
Description Abstract Text
ABSTRACT Chronic wasting disease (CWD) affecting various species of cervids in North American and Northern Europe represents a serious problem, because it continues to propagate uncontrollably among wild and captive cervids. CWD appears to be very heterogeneous with multiple different strains and can be transmitted to other animal species. The risk of CWD transmission to humans is unknown which is a major concern because the number of sick animals and their geographical distribution is rapidly increasing. The mechanism by which CWD propagates so efficiently among cervids is also unknown. The main goal of this project is to utilize a set of highly innovative techniques to study the cellular, molecular and structural features of naturally occurring CWD strains and their potential for inter- species transmission, particularly focusing on the possibility that certain CWD strains may infect humans. We will also attempt to elucidate the atomic resolution structure of CWD prions using cryo-electron microscopy. The overarching hypothesis is that CWD exists as multiple strains in distinct individuals and even within the same individual in different brain cells and that inter- species transmission and zoonotic potential depend on the specific strain characteristics. The project is divided in the following specific aims:
(1) Study the structural and molecular diversity of natural CWD strains and the high resolution three-dimensional structure of CWD prions.
(2) Understand CWD prion strain diversity in single brain cells isolated by laser capture microdissection and subsequently amplified by PMCA.
(3) Evaluate CWD inter-species transmission spillover potential and its effect on zoonotic potential.
(4) Analyze the deer-human prion species barrier in vivo using chimeric mice harboring human and cervid neuronal cells.
The studies included in this projects will address some of the most pressing questions regarding CWD, including
(i) the CWD prion strain variability,
(ii) the zoonotic potential of different CWD prion strains,
(iii) the atomic resolution structure of infectious prions and the structural basis of prion strains,
(iv) the cellular distribution of CWD prion strains in the brain and its gene expression consequences,
(v) the spillover potential of CWD to other animal species,
(vi) the potential role of intermediate species in the transmission of CWD prions to humans.
The findings generated in this project will be essential to design measures to prevent further propagation of CWD, and to avoid the emergence of new diseases with potentially disastrous consequences.
https://reporter.nih.gov/search/fXQ8kEmVa0mNDk1JNnx3Cw/project-details/11056103#description
18. Zoonotic potential of moose-derived chronic wasting disease prions after adaptation in intermediate species
Tomás Barrioa, Jean-Yves Doueta, Alvina Huora, Séverine Lugana, Naïma Arona, Hervé Cassarda, Sylvie L. Benestadb, Juan Carlos Espinosac, Juan María Torresc, Olivier Andréolettia
aUnité Mixte de Recherche de l’Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement 1225 Interactions Hôtes-Agents Pathogènes, École Nationale Vétérinaire de Toulouse, 31076 Toulouse, France; bNorwegian Veterinary Institute, P.O. Box 64, NO-1431 Ås, Norway; cCentro de Investigación en Sanidad Animal (CISA-INIA), 28130, Valdeolmos, Madrid, Spain
Aims: Chronic wasting disease (CWD) is an emerging prion disease in Europe. To date, cases have been reported in three Nordic countries and in several species, including reindeer (Rangifer tarandus), moose (Alces alces) and red deer (Cervus elaphus). Cumulating data suggest that the prion strains responsible for the European cases are distinct from those circulating in North America. The biological properties of CWD prions are still poorly documented, in particular their spillover and zoonotic capacities. In this study, we aimed at characterizing the interspecies transmission potential of Norwegian moose CWD isolates.
Materials and Methods: For that purpose, we performed experimental transmissions in a panel of transgenic models expressing the PrPC sequence of various species.
Results: On first passage, one moose isolate propagated in the ovine PrPC-expressing model (Tg338). After adaptation in this host, moose CWD prions were able to transmit in mice expressing either bovine or human PrPC with high efficacy.
Conclusions: These results suggest that CWD prions can acquire enhanced zoonotic properties following adaptation in an intermediate species.
Funding
Grant number: AAPG2020 EU-CWD, ICRAD2020 TCWDE, NRC2022 NorCWD
Acknowledgement
https://www.tandfonline.com/doi/full/10.1080/19336896.2024.2424058
“ After adaptation in this host, moose CWD prions were able to transmit in mice expressing either bovine or human PrPC with high efficacy.”
CDC CWD TSE Prion Update 2025
KEY POINTS
Chronic wasting disease affects deer, elk and similar animals in the United States and a few other countries.
The disease hasn't been shown to infect people.
However, it might be a risk to people if they have contact with or eat meat from animals infected with CWD.
https://www.cdc.gov/chronic-wasting/about/index.html
Volume 31, Number 4—April 2025
Research
Detection and Decontamination of Chronic Wasting Disease Prions during Venison Processing
https://wwwnc.cdc.gov/eid/article/31/4/24-1176_article
Prions in Muscles of Cervids with Chronic Wasting Disease, Norway
Volume 31, Number 2—February 2025
Research
Prions in Muscles of Cervids with Chronic Wasting Disease, Norway
Snip…
In summary, the results of our study indicate that prions are widely distributed in peripheral and edible tissues of cervids in Norway, including muscles. This finding highlights the risk of human exposure to small amounts of prions through handling and consuming infected cervids. Nevertheless, we note that this study did not investigate the zoonotic potential of the Norway CWD prions. In North America, humans have historically consumed meat from CWD-infected animals, which has been documented to harbor prions (35,44–47). Despite the potential exposure to prions, no epidemiologic evidence indicates a correlation between the occurrence of CWD cases in animals and the prevalence of human prion diseases (48). A recent bioassay study reported no transmissions from 3 Nordic isolates into transgenic mice expressing human PrP (49). Therefore, our findings should be interpreted with caution in terms of human health implications, and further research is required to determine the zoonotic potential of these CWD strains.
The presence of prions in peripheral tissues indicates that CWD may have a systemic nature in all Norwegian cervid species, challenging the view that prions are exclusively localized in the CNS in sporadic CWD of moose and red deer. Our findings expand the notion of just how widely distributed prions can be in cervids affected with CWD and call into question the capability of emerging CWD strains in terms of infectivity to other species, including humans.
Appendix
https://wwwnc.cdc.gov/eid/article/31/2/24-0903-app1.pdf
https://wwwnc.cdc.gov/eid/article/31/2/24-0903_article
Volume 31, Number 2—February 2025
Dispatch
Detection of Chronic Wasting Disease Prions in Raw, Processed, and Cooked Elk Meat, Texas, USA
Rebeca Benavente, Fraser Brydon, Francisca Bravo-Risi, Paulina Soto, J. Hunter Reed, Mitch Lockwood, Glenn Telling, Marcelo A. Barria, and Rodrigo MoralesComments to Author
Snip…
CWD prions have been detected in the muscle of both farmed and wild deer (10), and at concentrations relevant to sustain disease transmission (11). CWD prions have also been identified across several cervid species and in multiple tissues, including lymph nodes, spleen, tongue, intestines, adrenal gland, eyes, reproductive tissues, ears, lungs, and liver, among others (12–14). Those findings raise concerns about the safety of ingesting processed meats that contain tissues other than skeletal muscle (15) (Appendix). https://wwwnc.cdc.gov/eid/article/31/2/24-0906-app1.pdf .
In addition, those findings highlight the need for continued vigilance and research on the transmission risks of prion diseases and for development of new preventative and detection measures to ensure the safety of the human food supply.
Snip…
Overall, our study results confirm previous reports describing the presence of CWD prions in elk muscles (13). The data also demonstrated CWD prion persistence in food products even after processing through different procedures, including the addition of salts, spices, and other edible elements. Of note, our data show that exposure to high temperatures used to cook the meat increased the availability of prions for in vitro amplification. Considering the potential implications in food safety and public health, we believe that the findings described in this study warrant further research. Our results suggest that although the elk meat used in this study resisted different manipulations involved in subsequent consumption by humans, their zoonotic potential was limited. Nevertheless, even though no cases of CWD transmission to human have been reported, the potential for human infection is still unclear and continued monitoring for zoonotic potential is warranted.
https://wwwnc.cdc.gov/eid/article/31/2/24-0906_article
Volume 31, Number 1—January 2025
Dispatch
Detection of Prions in Wild Pigs (Sus scrofa) from Areas with Reported Chronic Wasting Disease Cases, United States
Abstract
Using a prion amplification assay, we identified prions in tissues from wild pigs (Sus scrofa) living in areas of the United States with variable chronic wasting disease (CWD) epidemiology. Our findings indicate that scavenging swine could play a role in disseminating CWD and could therefore influence its epidemiology, geographic distribution, and interspecies spread.
Snip…
Conclusions In summary, results from this study showed that wild pigs are exposed to cervid prions, although the pigs seem to display some resistance to infection via natural exposure. Future studies should address the susceptibility of this invasive animal species to the multiple prion strains circulating in the environment. Nonetheless, identification of CWD prions in wild pig tissues indicated the potential for pigs to move prions across the landscape, which may, in turn, influence the epidemiology and geographic spread of CWD.
https://wwwnc.cdc.gov/eid/article/%2031/1/24-0401_article
Detection of chronic wasting disease prions in processed meats
Rebeca Benavente1 , Francisca Bravo1,2, J. Hunter Reed3 , Mitch Lockwood3 , Glenn Telling4 , Rodrigo Morales1,2 1 Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; 2 Universidad Bernardo O’Higgins. Santiago, Chile; 3 Texas Parks and Wildlife Department, Texas, USA. 4 Prion Research Center, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
Aims: identify the presence of CWD prions in processed meats derived from elk.
Materials and Methods: In this study, we analyzed different processed meats derived from a CWD-positive (pre-clinical) free-ranging elk. Products tested included filets, sausages, boneless steaks, burgers, seasoned chili meats, and spiced meats. The presence of CWD-prions in these samples were assessed by PMCA using deer and elk substrates. The same analyses were performed in grilled and boiled meats to evaluate the resistance of the infectious agent to these procedures.
Results: Our results show positive prion detection in all the samples analyzed using deer and elk substrates. Surprisingly, cooked meats displayed increased seeding activities. This data suggests that CWD-prions are available to people even after meats are processed and cooked.
Conclusions: These results suggest CWD prions are accessible to humans through meats, even after processing and cooking. Considering the fact that these samples were collected from already processed specimens, the availability of CWD prions to humans is probably underestimated.
Funded by: NIH and USDA
Grant number: 1R01AI132695 and APP-20115 to RM
Acknowledgement: We would like to thank TPWD personnel for providing us with valuable samples
"Our results show positive prion detection in all the samples analyzed using deer and elk substrates. Surprisingly, cooked meats displayed increased seeding activities."
end...
PRION 2023 CONTINUED;
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
The detection and decontamination of chronic wasting disease prions during venison processing
Aims: There is a growing concern that chronic wasting disease (CWD) prions in venison pose a risk to human health. CWD prions accumulate in infected deer tissues that commonly enter the human food chain through meat processing and consumption. The United States (US) Food and Drug Administration and US Department of Agriculture now formally consider CWD-positive venison unfit for human and animal consumption. Yet, the degree to which prion contamination occurs during routine venison processing is unknown. Here, we use environmental surface swab methods to:
a) experimentally test meat processing equipment (i.e., stainless steel knives and polyethylene cutting boards) before and after processing CWD-positive venison and
b) test the efficacy of five different disinfectant types (i.e., Dawn dish soap, Virkon-S, Briotech, 10% bleach, and 40% bleach) to determine prion decontamination efficacy.
Materials and Methods: We used a real-time quaking-induced conversion (RT-QuIC) assay to determine CWD infection status of venison and to detect CWD prions in the swabs. We collected three swabs per surface and ran eight technical replicates on RT-QuIC.
Results: CWD prions were detected on all cutting boards (n= 3; replicates= 8/8, 8/8, 8/8 and knives (n= 3; replicates= 8/8, 8/8, 8/8) used in processing CWD-positive venison, but not on those used for CWD-negative venison. After processing CWD-positive venison, allowing the surfaces to dry, and washing the cutting board with Dawn dish soap, we detected CWD prions on the cutting board surface (n= 3; replicates= 8/8, 8/8, 8/8) but not on the knife (n= 3, replicates = 0/8, 0/8, 0/8). Similar patterns were observed with Briotech (cutting board: n= 3; replicates= 7/8, 1/8, 0/8; knife: n= 3; replicates = 0/8, 0/8, 0/8). We did not detect CWD prions on the knives or cutting boards after disinfecting with Virkon-S, 10% bleach, and 40% bleach.
Conclusions: These preliminary results suggest that Dawn dish soap and Briotech do not reliably decontaminate CWD prions from these surfaces. Our data suggest that Virkon-S and various bleach concentrations are more effective in reducing prion contamination of meat processing surfaces; however, surface type may also influence the ability of prions to adsorb to surfaces, preventing complete decontamination. Our results will directly inform best practices to prevent the introduction of CWD prions into the human food chain during venison processing.
Prion 2023 Abstracts
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
DETECTION OF CHRONIC WASTING DISEASE PRIONS IN PROCESSED MEATS.
Abstract
The zoonotic potential of chronic wasting disease (CWD) remains unknown. Currently, there are no known natural cases of CWD transmission to humans but increasing evidence suggests that the host range of CWD is not confined only to cervid species. Alarmingly, recent experimental evidence suggests that certain CWD isolates can induce disease in non-human primates. While the CDC strongly recommends determining CWD status in animals prior to consumption, this practice is voluntary. Consequently, it is plausible that a proportion of the cervid meat entering the human food chain may be contaminated with CWD. Of additional concern is that traditional diagnostic techniques used to detect CWD have relatively low sensitivity and are only approved for use in tissues other than those typically ingested by humans. In this study, we analyzed different processed meats derived from a pre-clinical, CWD-positive free-ranging elk. Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats. CWD-prion presence in these products were assessed by PMCA using deer and elk substrates. Our results show positive prion detection in all products. To confirm the resilience of CWD-prions to traditional cooking methods, we grilled and boiled the meat products and evaluated them for any remnant PMCA seeding activity. Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking. Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
***> Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats.
***> CWD-prion presence in these products were assessed by PMCA using deer and elk substrates.
***> Our results show positive prion detection in all products.
***> Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking.
***> Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true
Transmission of prion infectivity from CWD-infected macaque tissues to rodent models demonstrates the zoonotic potential of chronic wasting disease.
Samia Hannaoui1,2, Ginny Cheng1,2, Wiebke Wemheuer3, Walter Schulz-Schaeffer3, Sabine Gilch1,2, Hermann Schatzl1,2 1University of Calgary, Calgary, Canada. 2Calgary Prion Research Unit, Calgary, Canada. 3Institute of Neuropathology, Medical Faculty, Saarland University, Homburg/Saar, Germany
Snip…
***> Further passage to cervidized mice revealed transmission with a 100% attack rate.
***> Our findings demonstrate that macaques, considered the best model for the zoonotic potential of prions, were infected upon CWD challenge, including the oral one.
****> The disease manifested as atypical in macaques and initial transgenic mouse transmissions, but with infectivity present at all times, as unveiled in the bank vole model with an unusual tissue tropism.
***> Epidemiologic surveillance of prion disease among cervid hunters and people likely to have consumed venison contaminated with chronic wasting disease
=====
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true
Transmission of Cervid Prions to Humanized Mice Demonstrates the Zoonotic Potential of CWD
Samia Hannaouia, Irina Zemlyankinaa, Sheng Chun Changa, Maria Immaculata Arifina, Vincent Béringueb, Debbie McKenziec, Hermann M. Schatzla, and Sabine Gilcha
Results: Here, we provide the strongest evidence supporting the zoonotic potential of CWD prions, and their possible phenotype in humans. Inoculation of mice expressing human PrPCwith deer CWD isolates (strains Wisc-1 and 116AG) resulted in atypical clinical manifestations in > 75% of the mice, with myoclonus as leading clinical sign. Most of tg650brain homogenates were positive for seeding activity in RT-QuIC. Clinical disease and presentation was transmissible to tg650 mice and bank voles. Intriguingly, protease-resistant PrP in the brain of tg650 mice resembled that found in a familial human prion disease and was transmissible upon passage. Abnormal PrP aggregates upon infection with Wisc-1 were detectable in thalamus, hypothalamus, and midbrain/pons regions.
Unprecedented in human prion disease, feces of CWD-inoculated tg650 mice harbored prion seeding activity and infectious prions, as shown by inoculation of bank voles and tg650 with fecal homogenates.
Conclusions: This is the first evidence that CWD can infect humans and cause disease with a distinctive clinical presentation, signature, and tropism, which might be transmissible between humans while current diagnostic assays might fail to detect it. These findings have major implications for public health and CWD-management.
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
The finding that infectious PrPSc was shed in fecal material of CWD-infected humanized mice and induced clinical disease, different tropism, and typical three banding pattern-PrPres in bank voles that is transmissible upon second passage is highly concerning for public health. The fact that this biochemical signature in bank voles resembles that of the Wisc-1 original deer isolate and is different from that of bvWisc-1, in the migration profile and the glyco-form-ratio, is valid evidence that these results are not a product of contamination in our study. If CWD in humans is found to be contagious and transmissible among humans, as it is in cervids [57], the spread of the disease within humans might become endemic.
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Acta Neuropathol 144, 767–784 (2022). https://doi.org/10.1007/s00401-022-02482-9
Published
22 August 2022
https://link.springer.com/article/10.1007/s00401-022-02482-9
Fortuitous generation of a zoonotic cervid prion strain
Aims: Whether CWD prions can infect humans remains unclear despite the very substantial scale and long history of human exposure of CWD in many states or provinces of USA and Canada. Multiple in vitro conversion experiments and in vivo animal studies indicate that the CWD-to-human transmission barrier is not unbreakable. A major long-term public health concern on CWD zoonosis is the emergence of highly zoonotic CWD strains. We aim to address the question of whether highly zoonotic CWD strains are possible.
Materials and Methods: We inoculated several sCJD brain samples into cervidized transgenic mice (Tg12), which were intended as negative controls for bioassays of brain tissues from sCJD cases who had potentially been exposed to CWD. Some of the Tg12 mice became infected and their brain tissues were further examined by Western blot as well as serial passages in humanized or cervidized mice.
Results: Passage of sCJDMM1 in transgenic mice expressing elk PrP (Tg12) resulted in a “cervidized” CJD strain that we termed CJDElkPrP. We observed 100% transmission of the original CJDElkPrP in transgenic mice expressing human PrP. We passaged CJDElkPrP two more times in the Tg12 mice. We found that such second and third passage CJDElkPrP prions retained 100% transmission rate in the humanized mice, despite that the natural elk CWD isolates and CJDElkPrP share the same elk PrP sequence. In contrast, we and others found zero or poor transmission of natural elk CWD isolates in humanized mice.
Conclusions: Our data indicate that highly zoonotic cervid prion strains are not only possible but also can retain zoonotic potential after serial passages in cervids, suggesting a very significant and serious long-term risk of CWD zoonosis given that the broad and continuing spread of CWD prions will provide fertile grounds for the emergence of zoonotic CWD strains over time.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
The finding that infectious PrPSc was shed in fecal material of CWD-infected humanized mice and induced clinical disease, different tropism, and typical three banding pattern-PrPres in bank voles that is transmissible upon second passage is highly concerning for public health. The fact that this biochemical signature in bank voles resembles that of the Wisc-1 original deer isolate and is different from that of bvWisc-1, in the migration profile and the glyco-form-ratio, is valid evidence that these results are not a product of contamination in our study. If CWD in humans is found to be contagious and transmissible among humans, as it is in cervids [57], the spread of the disease within humans might become endemic.
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Acta Neuropathol 144, 767–784 (2022). https://doi.org/10.1007/s00401-022-02482-9
Published
22 August 2022
https://link.springer.com/article/10.1007/s00401-022-02482-9
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Samia Hannaoui1 · Irina Zemlyankina1 · Sheng Chun Chang1 · Maria Immaculata Arifn1 · Vincent Béringue2 · Debbie McKenzie3 · Hermann M. Schatzl1 · Sabine Gilch1
Received: 24 May 2022 / Revised: 5 August 2022 / Accepted: 7 August 2022
© The Author(s) 2022
Abstract
Prions cause infectious and fatal neurodegenerative diseases in mammals. Chronic wasting disease (CWD), a prion disease of cervids, spreads efficiently among wild and farmed animals. Potential transmission to humans of CWD is a growing concern due to its increasing prevalence. Here, we provide evidence for a zoonotic potential of CWD prions, and its probable signature using mice expressing human prion protein (PrP) as an infection model. Inoculation of these mice with deer CWD isolates resulted in atypical clinical manifestation with prion seeding activity and efficient transmissible infectivity in the brain and, remarkably, in feces, but without classical neuropathological or Western blot appearances of prion diseases. Intriguingly, the protease-resistant PrP in the brain resembled that found in a familial human prion disease and was transmissible upon second passage. Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
Keywords Chronic wasting disease · CWD · Zoonotic potential · Prion strains · Zoonotic prions
HIGHLIGHTS OF THIS STUDY
================================
Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
In this study, we evaluated the zoonotic potential of CWD using a transgenic mouse model overexpressing human M129-PrPC (tg650 [12]). We inoculated tg650 mice intracerebrally with two deer CWD isolates, Wisc-1 and 116AG [22, 23, 27, 29]. We demonstrate that this transgenic line was susceptible to infection with CWD prions and displayed a distinct leading clinical sign, an atypical PrPSc signature and unusual fecal shedding of infectious prions. Importantly, these prions generated by the human PrP transgenic mice were transmissible upon passage. Our results are the first evidence of a zoonotic risk of CWD when using one of the most common CWD strains, Wisc-1/CWD1 for infection. We demonstrated in a human transgenic mouse model that the species barrier for transmission of CWD to humans is not absolute. The fact that its signature was not typical raises the questions whether CWD would manifest in humans as a subclinical infection, whether it would arise through direct or indirect transmission including an intermediate host, or a silent to uncovered human-to-human transmission, and whether current detection techniques will be suffcient to unveil its presence.
Our findings strongly suggest that CWD should be regarded as an actual public health risk. Here, we use humanized mice to show that CWD prions can cross the species barrier to humans, and remarkably, infectious prions can be excreted in feces.
Our results indicate that if CWD crosses the species-barrier to humans, it is unlikely to resemble the most common forms of human prion diseases with respect to clinical signs, tissue tropism and PrPSc signature. For instance, PrPSc in variable protease-sensitive prionopathy (VPSPr), a sporadic form of human prion disease, and in the genetic form Gerstmann-Sträussler-Scheinker syndrome (GSS) is defined by an atypical PK-resistant PrPSc fragment that is non-glycosylated and truncated at both C- and N-termini, with a molecular weight between 6 and 8 kDa [24, 44–46]. These biochemical features are unique and distinctive from PrPSc (PrP27-30) found in most other human or animal prion disease. The atypical PrPSc signature detected in brain homogenate of tg650 mice #321 (1st passage) and #3063 (2nd passage), and the 7–8 kDa fragment (Figs. 2, 4) are very similar to that of GSS, both in terms of migration profile and the N-terminal cleavage site.
CWD in humans might remain subclinical but with PrPSc deposits in the brain with an unusual morphology that does not resemble the patterns usually seen in different prion diseases (e.g., mouse #328; Fig. 3), clinical with untraceable abnormal PrP (e.g., mouse #327) but still transmissible and uncovered upon subsequent passage (e.g., mouse #3063; Fig. 4), or prions have other reservoirs than the usual ones, hence the presence of infectivity in feces (e.g., mouse #327) suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.
“suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.”
=================================
Supplementary Information The online version contains supplementary material available at
https://doi.org/10.1007/s00401-022-02482-9
snip...see full text;
https://link.springer.com/article/10.1007/s00401-022-02482-9
https://link.springer.com/content/pdf/10.1007/s00401-022-02482-9.pdf
EFSA Panel on Biological Hazards (BIOHAZ) Antonia Ricci Ana Allende Declan Bolton Marianne Chemaly Robert Davies Pablo Salvador Fernández Escámez ...
First published: 17 January 2018 https://doi.org/10.2903/j.efsa.2018.5132
also, see;
8. Even though human TSE‐exposure risk through consumption of game from European cervids can be assumed to be minor, if at all existing, no final conclusion can be drawn due to the overall lack of scientific data.
***> In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison.
The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids. It might be prudent considering appropriate measures to reduce such a risk, e.g. excluding tissues such as CNS and lymphoid tissues from the human food chain, which would greatly reduce any potential risk for consumers.. However, it is stressed that currently, no data regarding a risk of TSE infections from cervid products are available.
https://efsa.onlinelibrary.wiley.com/doi/full/10.2903/j.efsa.2018.5132
2004
Jeff Swann and his Mom, cwd link... sporadic CJD?, CBC NEWS Jeff Schwan sCJD, CWD, and Professor Aguzzi on BSE and sporadic CJD
????: CBCnews
https://histodb15.usz.ch/pages/Images/videos/video-004/video-004.html
2004
April 22, 2004, 10:30 AM CDT Guests: Patrick Singh, Terry Schwan, Janet Skarbek, Bill Fielding (BEGIN VIDEOTAPE) ANNOUNCER: DEBORAH NORVILLE TONIGHT.
https://www.nbcnews.com/id/wbna4806886
1997-11-10: Panorama - The British disease
https://histodb15.usz.ch/pages/Images/videos/video-009/video-009.html
TUESDAY, MAY 11, 2021
Conclusion
We believe that our patient’s case of CJD is highly suspicious for cervid etiology given the circumstances of the case as well as the strong evidence of plausibility reported in published literature. This is the first known case of CJD in a patient who had consumed deer antler velvet. Despite the confirmed diagnosis of CJD, a causal relationship between the patient’s disease and his consumption of deer antler velvet cannot be definitively concluded.
Supplemental data including molecular tissue sample analysis and autopsy findings could yield further supporting evidence. Given this patient’s clinical resemblance to CBD and the known histological similarities of CBD with CJD, clinicians should consider both diseases in the differential diagnosis of patients with a similarly esoteric presentation. Regardless of the origin of this patient’s disease, it is clear that the potential for prion transmission from cervids to humans should be further investigated by the academic community with considerable urgency.
https://thescipub.com/pdf/ajidsp.2021.43.48.pdf
''We believe that our patient’s case of CJD is highly suspicious for cervid etiology given the circumstances of the case as well as the strong evidence of plausibility reported in published literature. This is the first known case of CJD in a patient who had consumed deer antler velvet. Despite the confirmed diagnosis of CJD, a causal relationship between the patient’s disease and his consumption of deer antler velvet cannot be definitively concluded.''
https://thescipub.com/pdf/ajidsp.2021.43.48.pdf
CREUTZFELDT JAKOB DISEASE: A Unique Presentation of Creutzfeldt-Jakob Disease in a Patient Consuming Deer Antler Velvet
i was warning England and the BSE Inquiry about just this, way back in 1998, and was ask to supply information to the BSE Inquiry. for anyone that might be interested, see;
Singeltary submission to the BSE Inquiry on CJD and Nutritional Supplements 1998
ABOUT that deer antler spray and CWD TSE PRION... I have been screaming this since my neighbors mom died from cjd, and she had been taking a supplement that contained bovine brain, bovine eyeball, and other SRMs specified risk materials, the most high risk for mad cow disease. just saying...
I made a submission to the BSE Inquiry long ago during the BSE Inquiry days, and they seemed pretty interested.
Sender: "Patricia Cantos"
To: "Terry S Singeltary Sr. (E-mail)"
Subject: Your submission to the Inquiry
Date: Fri, 3 Jul 1998 10:10:05 +0100 3 July 1998
Mr Terry S Singeltary Sr. E-Mail: Flounder at wt.net Ref: E2979
Dear Mr Singeltary, Thank you for your E-mail message of the 30th of June 1998 providing the Inquiry with your further comments. Thank you for offering to provide the Inquiry with any test results on the nutritional supplements your mother was taking before she died. As requested I am sending you our general Information Pack and a copy of the Chairman's letter. Please contact me if your system cannot read the attachments. Regarding your question, the Inquiry is looking into many aspects of the scientific evidence on BSE and nvCJD.
I would refer you to the transcripts of evidence we have already heard which are found on our internet site at ;
http://www.bse.org.uk.
Could you please provide the Inquiry with a copy of the press article you refer to in your e-mail? If not an approximate date for the article so that we can locate it? In the meantime, thank you for you comments. Please do not hesitate to contact me on... snip...end...tss
everyone I tell this too gets it screwed up...MY MOTHER WAS NOT TAKING THOSE SUPPLEMENTS IPLEX (that I ever knew of). this was my neighbors mother that died exactly one year previously and to the day of sporadic CJD that was diagnosed as Alzheimer’s at first. my mother died exactly a year later from the Heidenhain Variant of Creutzfeldt Jakob Disease hvCJD, and exceedingly rare strains of the ever growing sporadic CJD’s. both cases confirmed. ...
kind regards, terry
TSEs i.e. mad cow disease's BSE/BASE and NUTRITIONAL SUPPLEMENTS IPLEX, mad by standard process; vacuum dried bovine BRAIN, bone meal, bovine EYE, veal Bone, bovine liver powder, bovine adrenal, vacuum dried bovine kidney, and vacuum dried porcine stomach. also; what about potential mad cow candy bars ? see their potential mad cow candy bar list too... THESE are just a few of MANY of just this ONE COMPANY...TSS
https://wwwnc.cdc.gov/eid/article/15/5/08-1458_article
http://www.spiegel.de/spiegel/print/d-18578755.html
http://web.archive.org/web/20121022162853/http://cdmrp.army.mil/prevfunded/nprp/NPRP_Summit_Final_Report.pdf
So, this is what we leave our children and grandchildren?
***> Creutzfeldt Jakob Disease CJD TSE Prion Cases Increasing March 2025
https://creutzfeldt-jakob-disease.blogspot.com/2025/03/creutzfeldt-jakob-disease-tse-prion.html
***> Creutzfeldt Jakob 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
https://creutzfeldt-jakob-disease.blogspot.com/
Iatrogenic Transmissible Spongiform Encephalopathy TSE Prion, CWD, our worst nightmare, what if?
https://itseprion.blogspot.com/
So, this is what we leave our children and grandchildren?
Terry S. Singeltary Sr.
Project Number 5R01NS121016-04
Contact PI/Project Leader SCHATZL, HERMANN M
Other PIs
Awardee Organization
UNIVERSITY OF CALGARY
Description
Abstract Text
The rapid expansion of chronic wasting disease (CWD), a prion disease of free-ranging and farmed deer, elk and moose, is a major and ongoing threat in North America. Approximately 1 in 36 Americans hunt deer and elk and eat venison, and it is estimated that 7,000 – 15,000 CWD-infected cervids are consumed annually. This fuels growing concerns about the human health risks imposed by CWD. There are no documented cases of CWD transmission to humans, even though with the long incubation periods of all prion diseases and the unknown presentation of CWD in humans definite conclusions are not possible. The zoonotic potential of prion diseases has been exemplified by bovine spongiform encephalopathy (BSE, mad cow disease) which resulted in a new form of human prion disease (vCJD). BSE was transmissible to Cynomolgus macaques and transgenic mice expressing the human prion protein. Initial results of CWD transmission studies to the same non-human primate and mouse models of human prion disease were not successful, corroborating the conclusion that the zoonotic potential of CWD is low, if not absent. Our groups were part of a consortium that inoculated Cynomolgus macaques via different routes with CWD. Some animals exhibited subtle clinical signs reminiscent of prion disease, and upon euthanasia, weak signs of vacuolation, PrPSc deposition and astrocytosis in the brain were found, while no proteinase K (PK) resistant prion protein (PrP) was detectable. We have now demonstrated for the first time that CWD from macaques can transmit clinical prion disease to transgenic mouse models of CWD and human prion disease, albeit in the absence of detectable PK-resistant PrP. Bona fide PrPSc was only detected upon 3rd passage from mouse to bank vole models. Altogether, this is the first evidence that CWD very likely has zoonotic potential. The goal of the current proposal is to redefine the zoonotic potential of CWD by characterizing the biological properties of CWD prions emerging upon experimental transmission into macaques, for obtaining important information on how CWD could manifest in humans.
In Aim 1, we will study whether CWD from macaque (CWDmac) in bank voles represents a new prion strain, by comparing biochemical and biological properties to an array of known prion strains from different species.
Aim 2 addresses the question whether CWDmac represents an intermediate prion strain, adaptable to cervids or humans upon passage, and possessing an expanded host range. We will address this by in vivo passage in cervidized or humanized mouse models. In vitro, we will utilize serial PMCA and a newly generated PrP0/0 cell culture model for infection, upon reconstitution with PrP from different species.
In Aim 3, we will shed light on the observed dissociation between infectivity and the presence of bona fide PrPSc. We propose to identify atypical PrP fragments associated with CWDmac, and we will elucidate brain cell responses to CWDmac exposure by innovative single cell RNA sequencing. In summary, our studies will uncover the possible manifestation of CWD in humans, which is of critical importance for drawing definite conclusions about the zoonotic potential of CWD.
Public Health Relevance Statement
The zoonotic potential of chronic wasting disease (CWD) is unclear to date. We provide the first evidence by transmission experiments to different transgenic mouse models and bank voles that Cynomolgus macaques inoculated via different routes with CWD-positive cervid tissues harbor infectious prions that elicit clinical disease in rodents. Our proposed studies will unravel the properties of these prions, how they will adapt to humans and which pathways are activated in brain cells and associated with clinical disease. Results from these studies uncover the potential manifestation of CWD in humans, which is highly relevant for human health.
https://eventos.galoa.com.br/prion-2025/page/5178-home
Project 3A: CWD Prion Shedding and Environmental Contamination: Role in Transmission and Zoonotic
Parent Project Number 5P01AI077774-14
Sub-Project ID 5512
Contact PI/Project Leader HOOVER, EDWARD ARTHUR
Awardee Organization UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
Description
Abstract Text
Chronic wasting disease (CWD) is an emergent, highly transmissible, geographically expanding, prion disease of both wild and captive cervids. CWD is unique among prion diseases in its facile contagion and environmental persistence. Its expanding geographical range, combined with the increasing transport of animals and animal products, portend its continued expansion and diversification. The zoonotic potential of CWD remains poorly understood. CWD endemic areas interface cervids with livestock species and humans, posing obvious zoonotic risks that over time will increase. While it is known that strains of CWD exist, nothing is known about the zoonotic potential of these strains. Work from our applicant group has shown that CWD infected cervids continually shed prions into the environment and that previously unrecognized environmental factors can influence the emergence of a dominant strain from a mixture. The ability to recognize the zoonotic potential of CWD strains is central to mitigating CWD transmission risk. The central hypothesis for work described here is that CWD strains evolve continuously due to a combination of both host and environmental factors. We will test this hypothesis by:
i) determining the evolution and zoonotic impact of CWD strains in the native cervid species;
ii) leveraging our unique animal resources, expertise, and in vivo & in vitro methodologies to assess environmental factors that alter CWD strain selection and evolution and
iii) evaluate zoonotic potential of CWD strains by a complementary combination of in vitro amplification assays and animal transmission studies.
The results will provide new information about this emergent transmissible prion disease and the risk it poses to humans and other species.
https://reporter.nih.gov/project-details/11056111#description
Project 3B: Pathogenesis Transmission and Detection of Zoonotic Prion Diseases
Parent Project Number 5P01AI077774-14
Sub-Project ID 5513
Contact PI/Project Leader BARTZ, JASON C
Awardee Organization UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
Description Abstract Text
Project Summary: Chronic wasting disease (CWD) is an emergent, highly transmissible, geographically expanding, prion disease of both wild and captive cervids. CWD is unique among prion diseases in its facile contagion and environmental persistence. Its expanding geographical range, combined with the increasing transport of animals and animal products, portend its continued expansion and diversification. The zoonotic potential of CWD remains poorly understood. CWD endemic areas interface cervids with livestock species and humans, posing obvious zoonotic risks that over time will increase. While it is known that strains of CWD exist, nothing is known about the zoonotic potential of these strains. Work from our applicant group has shown that CWD- infected cervids continually shed prions into the environment and that previously unrecognized environmental factors can influence the emergence of a dominant strain from a mixture. The ability to recognize the zoonotic potential of CWD strains is central to mitigating CWD transmission risk. The central hypothesis for work described here is that CWD strains evolve continuously due to a combination of both host and environmental factors. We will test this hypothesis by:
i) determining the evolution and zoonotic impact of CWD strains in the native cervid species;
ii) leveraging our unique animal resources, expertise, and in vivo & in vitro methodologies to assess environmental factors that alter CWD strain selection and evolution and
iii) evaluate zoonotic potential of CWD strains by a complementary combination of in vitro amplification assays and animal transmission studies.
The results will provide new information about this emergent transmissible prion disease and the risk it poses to humans and other species.
https://reporter.nih.gov/project-details/11056115#description
Project 1: Modeling the Mechanisms of Prion Transmission, Strain Selection, Mutation and Species Barrier in Transgenic Mice
Parent Project Number 5P01AI077774-14
Sub-Project ID 5510
Contact PI/Project Leader TELLING, GLENN C
Awardee Organization UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
Description Abstract Text
Our broad, long-term objectives are to are to decipher the mechanisms by which infectious prions replicate, encode strain information, and evolve to acquire new properties. We propose four Specific Aims to address our central hypothesis that incompletely adapted prion strains are comprised of poorly optimized ensembles of PrPSc quasi species conformers that evolve under selective pressure towards states of enhanced stability and pathogenicity. Our particular focus is chronic wasting disease (CWD), an uncontrollable contagious epidemic of cervids of uncertain zoonotic potential. Using genetically engineered CWD-susceptible mice, cultured cells, cell free amplification, and antibodies recognizing defined conformation-dependent PrP epitopes,
Aim I will address the mechanism of adaptation of unstable emergent CWD prions in response to physical and chemical constraints.
In Aim II we will address the hypothesis that that residue 226 and other cervid PrP polymorphisms influence selection of distinct portfolios of CWD strain conformers with different adaptive potentials. Using gene targeted mice expressing physiologically controlled levels of PrP variants and in vitro systems for prion replication, we will characterize the properties of strains propagated in these backgrounds and explore whether interference between them affects selection and adaptation of CWD.
In Aim III, we will assess the properties of emergent Norwegian moose and reindeer CWD strains experimentally propagated in deer and compare with established North American CWD.
Aim IV will address an unmet need in the field of significant importance, namely the paucity of model systems and tools for studying human prions. Using newly generated gene targeted mice expressing physiological levels of human PrP and novel approaches to derive susceptible human neuroblastoma cells, we will assess the zoonotic potential of emergent CWD strains and their adapted derivatives propagated in different cervid PrP backgrounds. Our ultimate goal is to assess and manage the risk posed to humans from continually evolving prions, specifically those causing CWD, by understanding the means by which they propagate and exist as heritable strains with protean host range properties that adapt and evolve under selective pressure.
https://reporter.nih.gov/project-details/11056096#description
Project 2
Parent Project Number 5P01AI077774-14
Sub-Project ID 5511
Contact PI/Project Leader SOTO, CLAUDIO
Awardee Organization UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
Description Abstract Text
ABSTRACT Chronic wasting disease (CWD) affecting various species of cervids in North American and Northern Europe represents a serious problem, because it continues to propagate uncontrollably among wild and captive cervids. CWD appears to be very heterogeneous with multiple different strains and can be transmitted to other animal species. The risk of CWD transmission to humans is unknown which is a major concern because the number of sick animals and their geographical distribution is rapidly increasing. The mechanism by which CWD propagates so efficiently among cervids is also unknown. The main goal of this project is to utilize a set of highly innovative techniques to study the cellular, molecular and structural features of naturally occurring CWD strains and their potential for inter- species transmission, particularly focusing on the possibility that certain CWD strains may infect humans. We will also attempt to elucidate the atomic resolution structure of CWD prions using cryo-electron microscopy. The overarching hypothesis is that CWD exists as multiple strains in distinct individuals and even within the same individual in different brain cells and that inter- species transmission and zoonotic potential depend on the specific strain characteristics. The project is divided in the following specific aims:
(1) Study the structural and molecular diversity of natural CWD strains and the high resolution three-dimensional structure of CWD prions.
(2) Understand CWD prion strain diversity in single brain cells isolated by laser capture microdissection and subsequently amplified by PMCA.
(3) Evaluate CWD inter-species transmission spillover potential and its effect on zoonotic potential.
(4) Analyze the deer-human prion species barrier in vivo using chimeric mice harboring human and cervid neuronal cells.
The studies included in this projects will address some of the most pressing questions regarding CWD, including
(i) the CWD prion strain variability,
(ii) the zoonotic potential of different CWD prion strains,
(iii) the atomic resolution structure of infectious prions and the structural basis of prion strains,
(iv) the cellular distribution of CWD prion strains in the brain and its gene expression consequences,
(v) the spillover potential of CWD to other animal species,
(vi) the potential role of intermediate species in the transmission of CWD prions to humans.
The findings generated in this project will be essential to design measures to prevent further propagation of CWD, and to avoid the emergence of new diseases with potentially disastrous consequences.
https://reporter.nih.gov/search/fXQ8kEmVa0mNDk1JNnx3Cw/project-details/11056103#description
18. Zoonotic potential of moose-derived chronic wasting disease prions after adaptation in intermediate species
Tomás Barrioa, Jean-Yves Doueta, Alvina Huora, Séverine Lugana, Naïma Arona, Hervé Cassarda, Sylvie L. Benestadb, Juan Carlos Espinosac, Juan María Torresc, Olivier Andréolettia
aUnité Mixte de Recherche de l’Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement 1225 Interactions Hôtes-Agents Pathogènes, École Nationale Vétérinaire de Toulouse, 31076 Toulouse, France; bNorwegian Veterinary Institute, P.O. Box 64, NO-1431 Ås, Norway; cCentro de Investigación en Sanidad Animal (CISA-INIA), 28130, Valdeolmos, Madrid, Spain
Aims: Chronic wasting disease (CWD) is an emerging prion disease in Europe. To date, cases have been reported in three Nordic countries and in several species, including reindeer (Rangifer tarandus), moose (Alces alces) and red deer (Cervus elaphus). Cumulating data suggest that the prion strains responsible for the European cases are distinct from those circulating in North America. The biological properties of CWD prions are still poorly documented, in particular their spillover and zoonotic capacities. In this study, we aimed at characterizing the interspecies transmission potential of Norwegian moose CWD isolates.
Materials and Methods: For that purpose, we performed experimental transmissions in a panel of transgenic models expressing the PrPC sequence of various species.
Results: On first passage, one moose isolate propagated in the ovine PrPC-expressing model (Tg338). After adaptation in this host, moose CWD prions were able to transmit in mice expressing either bovine or human PrPC with high efficacy.
Conclusions: These results suggest that CWD prions can acquire enhanced zoonotic properties following adaptation in an intermediate species.
Funding
Grant number: AAPG2020 EU-CWD, ICRAD2020 TCWDE, NRC2022 NorCWD
Acknowledgement
https://www.tandfonline.com/doi/full/10.1080/19336896.2024.2424058
“ After adaptation in this host, moose CWD prions were able to transmit in mice expressing either bovine or human PrPC with high efficacy.”
CDC CWD TSE Prion Update 2025
KEY POINTS
Chronic wasting disease affects deer, elk and similar animals in the United States and a few other countries.
The disease hasn't been shown to infect people.
However, it might be a risk to people if they have contact with or eat meat from animals infected with CWD.
https://www.cdc.gov/chronic-wasting/about/index.html
Volume 31, Number 4—April 2025
Research
Detection and Decontamination of Chronic Wasting Disease Prions during Venison Processing
https://wwwnc.cdc.gov/eid/article/31/4/24-1176_article
Prions in Muscles of Cervids with Chronic Wasting Disease, Norway
Volume 31, Number 2—February 2025
Research
Prions in Muscles of Cervids with Chronic Wasting Disease, Norway
Snip…
In summary, the results of our study indicate that prions are widely distributed in peripheral and edible tissues of cervids in Norway, including muscles. This finding highlights the risk of human exposure to small amounts of prions through handling and consuming infected cervids. Nevertheless, we note that this study did not investigate the zoonotic potential of the Norway CWD prions. In North America, humans have historically consumed meat from CWD-infected animals, which has been documented to harbor prions (35,44–47). Despite the potential exposure to prions, no epidemiologic evidence indicates a correlation between the occurrence of CWD cases in animals and the prevalence of human prion diseases (48). A recent bioassay study reported no transmissions from 3 Nordic isolates into transgenic mice expressing human PrP (49). Therefore, our findings should be interpreted with caution in terms of human health implications, and further research is required to determine the zoonotic potential of these CWD strains.
The presence of prions in peripheral tissues indicates that CWD may have a systemic nature in all Norwegian cervid species, challenging the view that prions are exclusively localized in the CNS in sporadic CWD of moose and red deer. Our findings expand the notion of just how widely distributed prions can be in cervids affected with CWD and call into question the capability of emerging CWD strains in terms of infectivity to other species, including humans.
Appendix
https://wwwnc.cdc.gov/eid/article/31/2/24-0903-app1.pdf
https://wwwnc.cdc.gov/eid/article/31/2/24-0903_article
Volume 31, Number 2—February 2025
Dispatch
Detection of Chronic Wasting Disease Prions in Raw, Processed, and Cooked Elk Meat, Texas, USA
Rebeca Benavente, Fraser Brydon, Francisca Bravo-Risi, Paulina Soto, J. Hunter Reed, Mitch Lockwood, Glenn Telling, Marcelo A. Barria, and Rodrigo MoralesComments to Author
Snip…
CWD prions have been detected in the muscle of both farmed and wild deer (10), and at concentrations relevant to sustain disease transmission (11). CWD prions have also been identified across several cervid species and in multiple tissues, including lymph nodes, spleen, tongue, intestines, adrenal gland, eyes, reproductive tissues, ears, lungs, and liver, among others (12–14). Those findings raise concerns about the safety of ingesting processed meats that contain tissues other than skeletal muscle (15) (Appendix). https://wwwnc.cdc.gov/eid/article/31/2/24-0906-app1.pdf .
In addition, those findings highlight the need for continued vigilance and research on the transmission risks of prion diseases and for development of new preventative and detection measures to ensure the safety of the human food supply.
Snip…
Overall, our study results confirm previous reports describing the presence of CWD prions in elk muscles (13). The data also demonstrated CWD prion persistence in food products even after processing through different procedures, including the addition of salts, spices, and other edible elements. Of note, our data show that exposure to high temperatures used to cook the meat increased the availability of prions for in vitro amplification. Considering the potential implications in food safety and public health, we believe that the findings described in this study warrant further research. Our results suggest that although the elk meat used in this study resisted different manipulations involved in subsequent consumption by humans, their zoonotic potential was limited. Nevertheless, even though no cases of CWD transmission to human have been reported, the potential for human infection is still unclear and continued monitoring for zoonotic potential is warranted.
https://wwwnc.cdc.gov/eid/article/31/2/24-0906_article
Volume 31, Number 1—January 2025
Dispatch
Detection of Prions in Wild Pigs (Sus scrofa) from Areas with Reported Chronic Wasting Disease Cases, United States
Abstract
Using a prion amplification assay, we identified prions in tissues from wild pigs (Sus scrofa) living in areas of the United States with variable chronic wasting disease (CWD) epidemiology. Our findings indicate that scavenging swine could play a role in disseminating CWD and could therefore influence its epidemiology, geographic distribution, and interspecies spread.
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Conclusions In summary, results from this study showed that wild pigs are exposed to cervid prions, although the pigs seem to display some resistance to infection via natural exposure. Future studies should address the susceptibility of this invasive animal species to the multiple prion strains circulating in the environment. Nonetheless, identification of CWD prions in wild pig tissues indicated the potential for pigs to move prions across the landscape, which may, in turn, influence the epidemiology and geographic spread of CWD.
https://wwwnc.cdc.gov/eid/article/%2031/1/24-0401_article
Detection of chronic wasting disease prions in processed meats
Rebeca Benavente1 , Francisca Bravo1,2, J. Hunter Reed3 , Mitch Lockwood3 , Glenn Telling4 , Rodrigo Morales1,2 1 Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; 2 Universidad Bernardo O’Higgins. Santiago, Chile; 3 Texas Parks and Wildlife Department, Texas, USA. 4 Prion Research Center, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
Aims: identify the presence of CWD prions in processed meats derived from elk.
Materials and Methods: In this study, we analyzed different processed meats derived from a CWD-positive (pre-clinical) free-ranging elk. Products tested included filets, sausages, boneless steaks, burgers, seasoned chili meats, and spiced meats. The presence of CWD-prions in these samples were assessed by PMCA using deer and elk substrates. The same analyses were performed in grilled and boiled meats to evaluate the resistance of the infectious agent to these procedures.
Results: Our results show positive prion detection in all the samples analyzed using deer and elk substrates. Surprisingly, cooked meats displayed increased seeding activities. This data suggests that CWD-prions are available to people even after meats are processed and cooked.
Conclusions: These results suggest CWD prions are accessible to humans through meats, even after processing and cooking. Considering the fact that these samples were collected from already processed specimens, the availability of CWD prions to humans is probably underestimated.
Funded by: NIH and USDA
Grant number: 1R01AI132695 and APP-20115 to RM
Acknowledgement: We would like to thank TPWD personnel for providing us with valuable samples
"Our results show positive prion detection in all the samples analyzed using deer and elk substrates. Surprisingly, cooked meats displayed increased seeding activities."
end...
PRION 2023 CONTINUED;
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
The detection and decontamination of chronic wasting disease prions during venison processing
Aims: There is a growing concern that chronic wasting disease (CWD) prions in venison pose a risk to human health. CWD prions accumulate in infected deer tissues that commonly enter the human food chain through meat processing and consumption. The United States (US) Food and Drug Administration and US Department of Agriculture now formally consider CWD-positive venison unfit for human and animal consumption. Yet, the degree to which prion contamination occurs during routine venison processing is unknown. Here, we use environmental surface swab methods to:
a) experimentally test meat processing equipment (i.e., stainless steel knives and polyethylene cutting boards) before and after processing CWD-positive venison and
b) test the efficacy of five different disinfectant types (i.e., Dawn dish soap, Virkon-S, Briotech, 10% bleach, and 40% bleach) to determine prion decontamination efficacy.
Materials and Methods: We used a real-time quaking-induced conversion (RT-QuIC) assay to determine CWD infection status of venison and to detect CWD prions in the swabs. We collected three swabs per surface and ran eight technical replicates on RT-QuIC.
Results: CWD prions were detected on all cutting boards (n= 3; replicates= 8/8, 8/8, 8/8 and knives (n= 3; replicates= 8/8, 8/8, 8/8) used in processing CWD-positive venison, but not on those used for CWD-negative venison. After processing CWD-positive venison, allowing the surfaces to dry, and washing the cutting board with Dawn dish soap, we detected CWD prions on the cutting board surface (n= 3; replicates= 8/8, 8/8, 8/8) but not on the knife (n= 3, replicates = 0/8, 0/8, 0/8). Similar patterns were observed with Briotech (cutting board: n= 3; replicates= 7/8, 1/8, 0/8; knife: n= 3; replicates = 0/8, 0/8, 0/8). We did not detect CWD prions on the knives or cutting boards after disinfecting with Virkon-S, 10% bleach, and 40% bleach.
Conclusions: These preliminary results suggest that Dawn dish soap and Briotech do not reliably decontaminate CWD prions from these surfaces. Our data suggest that Virkon-S and various bleach concentrations are more effective in reducing prion contamination of meat processing surfaces; however, surface type may also influence the ability of prions to adsorb to surfaces, preventing complete decontamination. Our results will directly inform best practices to prevent the introduction of CWD prions into the human food chain during venison processing.
Prion 2023 Abstracts
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
DETECTION OF CHRONIC WASTING DISEASE PRIONS IN PROCESSED MEATS.
Abstract
The zoonotic potential of chronic wasting disease (CWD) remains unknown. Currently, there are no known natural cases of CWD transmission to humans but increasing evidence suggests that the host range of CWD is not confined only to cervid species. Alarmingly, recent experimental evidence suggests that certain CWD isolates can induce disease in non-human primates. While the CDC strongly recommends determining CWD status in animals prior to consumption, this practice is voluntary. Consequently, it is plausible that a proportion of the cervid meat entering the human food chain may be contaminated with CWD. Of additional concern is that traditional diagnostic techniques used to detect CWD have relatively low sensitivity and are only approved for use in tissues other than those typically ingested by humans. In this study, we analyzed different processed meats derived from a pre-clinical, CWD-positive free-ranging elk. Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats. CWD-prion presence in these products were assessed by PMCA using deer and elk substrates. Our results show positive prion detection in all products. To confirm the resilience of CWD-prions to traditional cooking methods, we grilled and boiled the meat products and evaluated them for any remnant PMCA seeding activity. Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking. Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
***> Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats.
***> CWD-prion presence in these products were assessed by PMCA using deer and elk substrates.
***> Our results show positive prion detection in all products.
***> Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking.
***> Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true
Transmission of prion infectivity from CWD-infected macaque tissues to rodent models demonstrates the zoonotic potential of chronic wasting disease.
Samia Hannaoui1,2, Ginny Cheng1,2, Wiebke Wemheuer3, Walter Schulz-Schaeffer3, Sabine Gilch1,2, Hermann Schatzl1,2 1University of Calgary, Calgary, Canada. 2Calgary Prion Research Unit, Calgary, Canada. 3Institute of Neuropathology, Medical Faculty, Saarland University, Homburg/Saar, Germany
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***> Further passage to cervidized mice revealed transmission with a 100% attack rate.
***> Our findings demonstrate that macaques, considered the best model for the zoonotic potential of prions, were infected upon CWD challenge, including the oral one.
****> The disease manifested as atypical in macaques and initial transgenic mouse transmissions, but with infectivity present at all times, as unveiled in the bank vole model with an unusual tissue tropism.
***> Epidemiologic surveillance of prion disease among cervid hunters and people likely to have consumed venison contaminated with chronic wasting disease
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https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true
Transmission of Cervid Prions to Humanized Mice Demonstrates the Zoonotic Potential of CWD
Samia Hannaouia, Irina Zemlyankinaa, Sheng Chun Changa, Maria Immaculata Arifina, Vincent Béringueb, Debbie McKenziec, Hermann M. Schatzla, and Sabine Gilcha
Results: Here, we provide the strongest evidence supporting the zoonotic potential of CWD prions, and their possible phenotype in humans. Inoculation of mice expressing human PrPCwith deer CWD isolates (strains Wisc-1 and 116AG) resulted in atypical clinical manifestations in > 75% of the mice, with myoclonus as leading clinical sign. Most of tg650brain homogenates were positive for seeding activity in RT-QuIC. Clinical disease and presentation was transmissible to tg650 mice and bank voles. Intriguingly, protease-resistant PrP in the brain of tg650 mice resembled that found in a familial human prion disease and was transmissible upon passage. Abnormal PrP aggregates upon infection with Wisc-1 were detectable in thalamus, hypothalamus, and midbrain/pons regions.
Unprecedented in human prion disease, feces of CWD-inoculated tg650 mice harbored prion seeding activity and infectious prions, as shown by inoculation of bank voles and tg650 with fecal homogenates.
Conclusions: This is the first evidence that CWD can infect humans and cause disease with a distinctive clinical presentation, signature, and tropism, which might be transmissible between humans while current diagnostic assays might fail to detect it. These findings have major implications for public health and CWD-management.
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
The finding that infectious PrPSc was shed in fecal material of CWD-infected humanized mice and induced clinical disease, different tropism, and typical three banding pattern-PrPres in bank voles that is transmissible upon second passage is highly concerning for public health. The fact that this biochemical signature in bank voles resembles that of the Wisc-1 original deer isolate and is different from that of bvWisc-1, in the migration profile and the glyco-form-ratio, is valid evidence that these results are not a product of contamination in our study. If CWD in humans is found to be contagious and transmissible among humans, as it is in cervids [57], the spread of the disease within humans might become endemic.
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Acta Neuropathol 144, 767–784 (2022). https://doi.org/10.1007/s00401-022-02482-9
Published
22 August 2022
https://link.springer.com/article/10.1007/s00401-022-02482-9
Fortuitous generation of a zoonotic cervid prion strain
Aims: Whether CWD prions can infect humans remains unclear despite the very substantial scale and long history of human exposure of CWD in many states or provinces of USA and Canada. Multiple in vitro conversion experiments and in vivo animal studies indicate that the CWD-to-human transmission barrier is not unbreakable. A major long-term public health concern on CWD zoonosis is the emergence of highly zoonotic CWD strains. We aim to address the question of whether highly zoonotic CWD strains are possible.
Materials and Methods: We inoculated several sCJD brain samples into cervidized transgenic mice (Tg12), which were intended as negative controls for bioassays of brain tissues from sCJD cases who had potentially been exposed to CWD. Some of the Tg12 mice became infected and their brain tissues were further examined by Western blot as well as serial passages in humanized or cervidized mice.
Results: Passage of sCJDMM1 in transgenic mice expressing elk PrP (Tg12) resulted in a “cervidized” CJD strain that we termed CJDElkPrP. We observed 100% transmission of the original CJDElkPrP in transgenic mice expressing human PrP. We passaged CJDElkPrP two more times in the Tg12 mice. We found that such second and third passage CJDElkPrP prions retained 100% transmission rate in the humanized mice, despite that the natural elk CWD isolates and CJDElkPrP share the same elk PrP sequence. In contrast, we and others found zero or poor transmission of natural elk CWD isolates in humanized mice.
Conclusions: Our data indicate that highly zoonotic cervid prion strains are not only possible but also can retain zoonotic potential after serial passages in cervids, suggesting a very significant and serious long-term risk of CWD zoonosis given that the broad and continuing spread of CWD prions will provide fertile grounds for the emergence of zoonotic CWD strains over time.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
The finding that infectious PrPSc was shed in fecal material of CWD-infected humanized mice and induced clinical disease, different tropism, and typical three banding pattern-PrPres in bank voles that is transmissible upon second passage is highly concerning for public health. The fact that this biochemical signature in bank voles resembles that of the Wisc-1 original deer isolate and is different from that of bvWisc-1, in the migration profile and the glyco-form-ratio, is valid evidence that these results are not a product of contamination in our study. If CWD in humans is found to be contagious and transmissible among humans, as it is in cervids [57], the spread of the disease within humans might become endemic.
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Acta Neuropathol 144, 767–784 (2022). https://doi.org/10.1007/s00401-022-02482-9
Published
22 August 2022
https://link.springer.com/article/10.1007/s00401-022-02482-9
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Samia Hannaoui1 · Irina Zemlyankina1 · Sheng Chun Chang1 · Maria Immaculata Arifn1 · Vincent Béringue2 · Debbie McKenzie3 · Hermann M. Schatzl1 · Sabine Gilch1
Received: 24 May 2022 / Revised: 5 August 2022 / Accepted: 7 August 2022
© The Author(s) 2022
Abstract
Prions cause infectious and fatal neurodegenerative diseases in mammals. Chronic wasting disease (CWD), a prion disease of cervids, spreads efficiently among wild and farmed animals. Potential transmission to humans of CWD is a growing concern due to its increasing prevalence. Here, we provide evidence for a zoonotic potential of CWD prions, and its probable signature using mice expressing human prion protein (PrP) as an infection model. Inoculation of these mice with deer CWD isolates resulted in atypical clinical manifestation with prion seeding activity and efficient transmissible infectivity in the brain and, remarkably, in feces, but without classical neuropathological or Western blot appearances of prion diseases. Intriguingly, the protease-resistant PrP in the brain resembled that found in a familial human prion disease and was transmissible upon second passage. Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
Keywords Chronic wasting disease · CWD · Zoonotic potential · Prion strains · Zoonotic prions
HIGHLIGHTS OF THIS STUDY
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Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
In this study, we evaluated the zoonotic potential of CWD using a transgenic mouse model overexpressing human M129-PrPC (tg650 [12]). We inoculated tg650 mice intracerebrally with two deer CWD isolates, Wisc-1 and 116AG [22, 23, 27, 29]. We demonstrate that this transgenic line was susceptible to infection with CWD prions and displayed a distinct leading clinical sign, an atypical PrPSc signature and unusual fecal shedding of infectious prions. Importantly, these prions generated by the human PrP transgenic mice were transmissible upon passage. Our results are the first evidence of a zoonotic risk of CWD when using one of the most common CWD strains, Wisc-1/CWD1 for infection. We demonstrated in a human transgenic mouse model that the species barrier for transmission of CWD to humans is not absolute. The fact that its signature was not typical raises the questions whether CWD would manifest in humans as a subclinical infection, whether it would arise through direct or indirect transmission including an intermediate host, or a silent to uncovered human-to-human transmission, and whether current detection techniques will be suffcient to unveil its presence.
Our findings strongly suggest that CWD should be regarded as an actual public health risk. Here, we use humanized mice to show that CWD prions can cross the species barrier to humans, and remarkably, infectious prions can be excreted in feces.
Our results indicate that if CWD crosses the species-barrier to humans, it is unlikely to resemble the most common forms of human prion diseases with respect to clinical signs, tissue tropism and PrPSc signature. For instance, PrPSc in variable protease-sensitive prionopathy (VPSPr), a sporadic form of human prion disease, and in the genetic form Gerstmann-Sträussler-Scheinker syndrome (GSS) is defined by an atypical PK-resistant PrPSc fragment that is non-glycosylated and truncated at both C- and N-termini, with a molecular weight between 6 and 8 kDa [24, 44–46]. These biochemical features are unique and distinctive from PrPSc (PrP27-30) found in most other human or animal prion disease. The atypical PrPSc signature detected in brain homogenate of tg650 mice #321 (1st passage) and #3063 (2nd passage), and the 7–8 kDa fragment (Figs. 2, 4) are very similar to that of GSS, both in terms of migration profile and the N-terminal cleavage site.
CWD in humans might remain subclinical but with PrPSc deposits in the brain with an unusual morphology that does not resemble the patterns usually seen in different prion diseases (e.g., mouse #328; Fig. 3), clinical with untraceable abnormal PrP (e.g., mouse #327) but still transmissible and uncovered upon subsequent passage (e.g., mouse #3063; Fig. 4), or prions have other reservoirs than the usual ones, hence the presence of infectivity in feces (e.g., mouse #327) suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.
“suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.”
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Supplementary Information The online version contains supplementary material available at
https://doi.org/10.1007/s00401-022-02482-9
snip...see full text;
https://link.springer.com/article/10.1007/s00401-022-02482-9
https://link.springer.com/content/pdf/10.1007/s00401-022-02482-9.pdf
Prion Conference 2018 Abstracts
P190 Human prion disease mortality rates by occurrence of chronic wasting disease in freeranging cervids, United States
Abrams JY (1), Maddox RA (1), Schonberger LB (1), Person MK (1), Appleby BS (2), Belay ED (1)
(1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA.
Background
Chronic wasting disease (CWD) is a prion disease of deer and elk that has been identified in freeranging cervids in 23 US states. While there is currently no epidemiological evidence for zoonotic transmission through the consumption of contaminated venison, studies suggest the CWD agent can cross the species barrier in experimental models designed to closely mimic humans. We compared rates of human prion disease in states with and without CWD to examine the possibility of undetermined zoonotic transmission.
Methods
Death records from the National Center for Health Statistics, case records from the National Prion Disease Pathology Surveillance Center, and additional state case reports were combined to create a database of human prion disease cases from 2003-2015. Identification of CWD in each state was determined through reports of positive CWD tests by state wildlife agencies. Age- and race-adjusted mortality rates for human prion disease, excluding cases with known etiology, were determined for four categories of states based on CWD occurrence: highly endemic (>16 counties with CWD identified in free-ranging cervids); moderately endemic (3-10 counties with CWD); low endemic (1-2 counties with CWD); and no CWD states. States were counted as having no CWD until the year CWD was first identified. Analyses stratified by age, sex, and time period were also conducted to focus on subgroups for which zoonotic transmission would be more likely to be detected: cases <55 years old, male sex, and the latter half of the study (2010-2015).
Results
Highly endemic states had a higher rate of prion disease mortality compared to non-CWD states (rate ratio [RR]: 1.12, 95% confidence interval [CI] = 1.01 - 1.23), as did low endemic states (RR: 1.15, 95% CI = 1.04 - 1.27). Moderately endemic states did not have an elevated mortality rate (RR: 1.05, 95% CI = 0.93 - 1.17). In age-stratified analyses, prion disease mortality rates among the <55 year old population were elevated for moderately endemic states (RR: 1.57, 95% CI = 1.10 – 2.24) while mortality rates were elevated among those ≥55 for highly endemic states (RR: 1.13, 95% CI = 1.02 - 1.26) and low endemic states (RR: 1.16, 95% CI = 1.04 - 1.29). In other stratified analyses, prion disease mortality rates for males were only elevated for low endemic states (RR: 1.27, 95% CI = 1.10 - 1.48), and none of the categories of CWD-endemic states had elevated mortality rates for the latter time period (2010-2015).
Conclusions
While higher prion disease mortality rates in certain categories of states with CWD in free-ranging cervids were noted, additional stratified analyses did not reveal markedly elevated rates for potentially sensitive subgroups that would be suggestive of zoonotic transmission. Unknown confounding factors or other biases may explain state-by-state differences in prion disease mortality.
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P172 Peripheral Neuropathy in Patients with Prion Disease
Wang H(1), Cohen M(1), Appleby BS(1,2)
(1) University Hospitals Cleveland Medical Center, Cleveland, Ohio (2) National Prion Disease Pathology Surveillance Center, Cleveland, Ohio.
Prion disease is a fatal progressive neurodegenerative disease due to deposition of an abnormal protease-resistant isoform of prion protein. Typical symptoms include rapidly progressive dementia, myoclonus, visual disturbance and hallucinations. Interestingly, in patients with prion disease, the abnormal protein canould also be found in the peripheral nervous system. Case reports of prion deposition in peripheral nerves have been reported. Peripheral nerve involvement is thought to be uncommon; however, little is known about the exact prevalence and features of peripheral neuropathy in patients with prion disease.
We reviewed autopsy-proven prion cases from the National Prion Disease Pathology Surveillance Center that were diagnosed between September 2016 to March 2017. We collected information regarding prion protein diagnosis, demographics, comorbidities, clinical symptoms, physical exam, neuropathology, molecular subtype, genetics lab, brain MRI, image and EMG reports. Our study included 104 patients. Thirteen (12.5%) patients had either subjective symptoms or objective signs of peripheral neuropathy. Among these 13 patients, 3 had other known potential etiologies of peripheral neuropathy such as vitamin B12 deficiency or prior chemotherapy. Among 10 patients that had no other clear etiology, 3 (30%) had familial CJD. The most common sCJD subtype was MV1-2 (30%), followed by MM1-2 (20%). The Majority of cases wasere male (60%). Half of them had exposure to wild game. The most common subjective symptoms were tingling and/or numbness of distal extremities. The most common objective finding was diminished vibratory sensation in the feet. Half of them had an EMG with the findings ranging from fasciculations to axonal polyneuropathy or demyelinating polyneuropathy.
Our study provides an overview of the pattern of peripheral neuropathy in patients with prion disease. Among patients with peripheral neuropathy symptoms or signs, majority has polyneuropathy. It is important to document the baseline frequency of peripheral neuropathy in prion diseases as these symptoms may become important when conducting surveillance for potential novel zoonotic prion diseases.
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P177 PrP plaques in methionine homozygous Creutzfeldt-Jakob disease patients as a potential marker of iatrogenic transmission
Abrams JY (1), Schonberger LB (1), Cali I (2), Cohen Y (2), Blevins JE (2), Maddox RA (1), Belay ED (1), Appleby BS (2), Cohen ML (2)
(1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA.
Background
Sporadic Creutzfeldt-Jakob disease (CJD) is widely believed to originate from de novo spontaneous conversion of normal prion protein (PrP) to its pathogenic form, but concern remains that some reported sporadic CJD cases may actually be caused by disease transmission via iatrogenic processes. For cases with methionine homozygosity (CJD-MM) at codon 129 of the PRNP gene, recent research has pointed to plaque-like PrP deposition as a potential marker of iatrogenic transmission for a subset of cases. This phenotype is theorized to originate from specific iatrogenic source CJD types that comprise roughly a quarter of known CJD cases.
Methods
We reviewed scientific literature for studies which described PrP plaques among CJD patients with known epidemiological links to iatrogenic transmission (receipt of cadaveric human grown hormone or dura mater), as well as in cases of reported sporadic CJD. The presence and description of plaques, along with CJD classification type and other contextual factors, were used to summarize the current evidence regarding plaques as a potential marker of iatrogenic transmission. In addition, 523 cases of reported sporadic CJD cases in the US from January 2013 through September 2017 were assessed for presence of PrP plaques.
Results
We identified four studies describing 52 total cases of CJD-MM among either dura mater recipients or growth hormone recipients, of which 30 were identified as having PrP plaques. While sporadic cases were not generally described as having plaques, we did identify case reports which described plaques among sporadic MM2 cases as well as case reports of plaques exclusively in white matter among sporadic MM1 cases. Among the 523 reported sporadic CJD cases, 0 of 366 MM1 cases had plaques, 2 of 48 MM2 cases had kuru plaques, and 4 of 109 MM1+2 cases had either kuru plaques or both kuru and florid plaques. Medical chart review of the six reported sporadic CJD cases with plaques did not reveal clinical histories suggestive of potential iatrogenic transmission.
Conclusions
PrP plaques occur much more frequently for iatrogenic CJD-MM cases compared to sporadic CJDMM cases. Plaques may indicate iatrogenic transmission for CJD-MM cases without a type 2 Western blot fragment. The study results suggest the absence of significant misclassifications of iatrogenic CJD as sporadic. To our knowledge, this study is the first to describe grey matter kuru plaques in apparently sporadic CJD-MM patients with a type 2 Western blot fragment.
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P180 Clinico-pathological analysis of human prion diseases in a brain bank series
Ximelis T (1), Aldecoa I (1,2), Molina-Porcel L (1,3), Grau-Rivera O (4), Ferrer I (5), Nos C (6), Gelpi E (1,7), Sánchez-Valle R (1,4)
(1) Neurological Tissue Bank of the Biobanc-Hospital ClÃnic-IDIBAPS, Barcelona, Spain (2) Pathological Service of Hospital ClÃnic de Barcelona, Barcelona, Spain (3) EAIA Trastorns Cognitius, Centre Emili Mira, Parc de Salut Mar, Barcelona, Spain (4) Department of Neurology of Hospital ClÃnic de Barcelona, Barcelona, Spain (5) Institute of Neuropathology, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Barcelona (6) General subdirectorate of Surveillance and Response to Emergencies in Public Health, Department of Public Health in Catalonia, Barcelona, Spain (7) Institute of Neurology, Medical University of Vienna, Vienna, Austria.
Background and objective:
The Neurological Tissue Bank (NTB) of the Hospital Clínic-Institut d‘Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain is the reference center in Catalonia for the neuropathological study of prion diseases in the region since 2001. The aim of this study is to analyse the characteristics of the confirmed prion diseases registered at the NTB during the last 15 years.
Methods:
We reviewed retrospectively all neuropathologically confirmed cases registered during the period January 2001 to December 2016.
Results:
176 cases (54,3% female, mean age: 67,5 years and age range: 25-86 years) of neuropathological confirmed prion diseases have been studied at the NTB. 152 cases corresponded to sporadic Creutzfeldt-Jakob disease (sCJD), 10 to genetic CJD, 10 to Fatal Familial Insomnia, 2 to GerstmannSträussler-Scheinker disease, and 2 cases to variably protease-sensitive prionopathy (VPSPr). Within sCJD subtypes the MM1 subtype was the most frequent, followed by the VV2 histotype.
Clinical and neuropathological diagnoses agreed in 166 cases (94%). The clinical diagnosis was not accurate in 10 patients with definite prion disease: 1 had a clinical diagnosis of Fronto-temporal dementia (FTD), 1 Niemann-Pick‘s disease, 1 Lewy Body‘s Disease, 2 Alzheimer‘s disease, 1 Cortico-basal syndrome and 2 undetermined dementia. Among patients with VPSPr, 1 had a clinical diagnosis of Amyotrophic lateral sclerosis (ALS) and the other one with FTD.
Concomitant pathologies are frequent in older age groups, mainly AD neuropathological changes were observed in these subjects.
Discussion:
A wide spectrum of human prion diseases have been identified in the NTB being the relative frequencies and main characteristics like other published series. There is a high rate of agreement between clinical and neuropathological diagnoses with prion diseases. These findings show the importance that public health has given to prion diseases during the past 15 years. Continuous surveillance of human prion disease allows identification of new emerging phenotypes. Brain tissue samples from these donors are available to the scientific community. For more information please visit:
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WA2 Oral transmission of CWD into Cynomolgus macaques: signs of atypical disease, prion conversion and infectivity in macaques and bio-assayed transgenic mice
Schatzl HM (1, 2), Hannaoui S (1, 2), Cheng Y-C (1, 2), Gilch S (1, 2), Beekes M (3), SchulzSchaeffer W (4), Stahl-Hennig C (5) and Czub S (2, 6)
(1) University of Calgary, Calgary Prion Research Unit, Calgary, Canada (2) University of Calgary, Faculty of Veterinary Medicine, Calgary, Canada, (3) Robert Koch Institute, Berlin, Germany, (4) University of Homburg/Saar, Homburg, Germany, (5) German Primate Center, Goettingen, Germany, (6) Canadian Food Inspection Agency (CFIA), Lethbridge, Canada.
To date, BSE is the only example of interspecies transmission of an animal prion disease into humans. The potential zoonotic transmission of CWD is an alarming issue and was addressed by many groups using a variety of in vitro and in vivo experimental systems. Evidence from these studies indicated a substantial, if not absolute, species barrier, aligning with the absence of epidemiological evidence suggesting transmission into humans. Studies in non-human primates were not conclusive so far, with oral transmission into new-world monkeys and no transmission into old-world monkeys. Our consortium has challenged 18 Cynomolgus macaques with characterized CWD material, focusing on oral transmission with muscle tissue. Some macaques have orally received a total of 5 kg of muscle material over a period of 2 years. After 5-7 years of incubation time some animals showed clinical symptoms indicative of prion disease, and prion neuropathology and PrPSc deposition were found in spinal cord and brain of euthanized animals. PrPSc in immunoblot was weakly detected in some spinal cord materials and various tissues tested positive in RT-QuIC, including lymph node and spleen homogenates. To prove prion infectivity in the macaque tissues, we have intracerebrally inoculated 2 lines of transgenic mice, expressing either elk or human PrP. At least 3 TgElk mice, receiving tissues from 2 different macaques, showed clinical signs of a progressive prion disease and brains were positive in immunoblot and RT-QuIC. Tissues (brain, spinal cord and spleen) from these and preclinical mice are currently tested using various read-outs and by second passage in mice. Transgenic mice expressing human PrP were so far negative for clear clinical prion disease (some mice >300 days p.i.). In parallel, the same macaque materials are inoculated into bank voles. Taken together, there is strong evidence of transmissibility of CWD orally into macaques and from macaque tissues into transgenic mouse models, although with an incomplete attack rate. The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology. Our ongoing studies will show whether the transmission of CWD into macaques and passage in transgenic mice represents a form of non-adaptive prion amplification, and whether macaque-adapted prions have the potential to infect mice expressing human PrP. The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD.
See also poster P103
***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD.
=====
WA16 Monitoring Potential CWD Transmission to Humans
Belay ED
Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA.
The spread of chronic wasting disease (CWD) in animals has raised concerns about increasing human exposure to the CWD agent via hunting and venison consumption, potentially facilitating CWD transmission to humans. Several studies have explored this possibility, including limited epidemiologic studies, in vitro experiments, and laboratory studies using various types of animal models. Most human exposures to the CWD agent in the United States would be expected to occur in association with deer and elk hunting in CWD-endemic areas. The Centers for Disease Control and Prevention (CDC) collaborated with state health departments in Colorado, Wisconsin, and Wyoming to identify persons at risk of CWD exposure and to monitor their vital status over time. Databases were established of persons who hunted in Colorado and Wyoming and those who reported consumption of venison from deer that later tested positive in Wisconsin. Information from the databases is periodically cross-checked with mortality data to determine the vital status and causes of death for deceased persons. Long-term follow-up of these hunters is needed to assess their risk of development of a prion disease linked to CWD exposure.
=====
P166 Characterization of CJD strain profiles in venison consumers and non-consumers from Alberta and Saskatchewan
Stephanie Booth (1,2), Lise Lamoureux (1), Debra Sorensen (1), Jennifer L. Myskiw (1,2), Megan Klassen (1,2), Michael Coulthart (3), Valerie Sim (4)
(1) Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg (2) Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg (3) Canadian CJD Surveillance System, Public Health Agency of Canada, Ottawa (4) Division of Neurology, Department of Medicine Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton.
Chronic wasting disease (CWD) is spreading rapidly through wild cervid populations in the Canadian provinces of Alberta and Saskatchewan. While this has implications for tourism and hunting, there is also concern over possible zoonotic transmission to humans who eat venison from infected deer. Whilst there is no evidence of any human cases of CWD to date, the Canadian CJD Surveillance System (CJDSS) in Canada is staying vigilant. When variant CJD occurred following exposure to BSE, the unique biochemical fingerprint of the pathologic PrP enabled a causal link to be confirmed. However, we cannot be sure what phenotype human CWD prions would present with, or indeed, whether this would be distinct from that see in sporadic CJD. Therefore we are undertaking a systematic analysis of the molecular diversity of CJD cases of individuals who resided in Alberta and Saskatchewan at their time of death comparing venison consumers and non-consumers, using a variety of clinical, imaging, pathological and biochemical markers. Our initial objective is to develop novel biochemical methodologies that will extend the baseline glycoform and genetic polymorphism typing that is already completed by the CJDSS. Firstly, we are reviewing MRI, EEG and pathology information from over 40 cases of CJD to select clinically affected areas for further investigation. Biochemical analysis will include assessment of the levels of protease sensitive and resistant prion protein, glycoform typing using 2D gel electrophoresis, testing seeding capabilities and kinetics of aggregation by quaking-induced conversion, and determining prion oligomer size distributions with asymmetric flow field fractionation with in-line light scattering. Progress and preliminary data will be presented. Ultimately, we intend to further define the relationship between PrP structure and disease phenotype and establish a baseline for the identification of future atypical CJD cases that may arise as a result of exposure to CWD.
=====
Source Prion Conference 2018 Abstracts
Volume 24, Number 8—August 2018
Research Susceptibility of Human Prion Protein to Conversion by Chronic Wasting Disease Prions
Marcelo A. BarriaComments to Author , Adriana Libori, Gordon Mitchell, and Mark W. Head Author affiliations: National CJD Research and Surveillance Unit, University of Edinburgh, Edinburgh, Scotland, UK (M.A. Barria, A. Libori, M.W. Head); National and OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada (G. Mitchell)
Abstract Chronic wasting disease (CWD) is a contagious and fatal neurodegenerative disease and a serious animal health issue for deer and elk in North America. The identification of the first cases of CWD among free-ranging reindeer and moose in Europe brings back into focus the unresolved issue of whether CWD can be zoonotic like bovine spongiform encephalopathy. We used a cell-free seeded protein misfolding assay to determine whether CWD prions from elk, white-tailed deer, and reindeer in North America can convert the human prion protein to the disease-associated form. We found that prions can convert, but the efficiency of conversion is affected by polymorphic variation in the cervid and human prion protein genes. In view of the similarity of reindeer, elk, and white-tailed deer in North America to reindeer, red deer, and roe deer, respectively, in Europe, a more comprehensive and thorough assessment of the zoonotic potential of CWD might be warranted.
snip...
Discussion Characterization of the transmission properties of CWD and evaluation of their zoonotic potential are important for public health purposes. Given that CWD affects several members of the family Cervidae, it seems reasonable to consider whether the zoonotic potential of CWD prions could be affected by factors such as CWD strain, cervid species, geographic location, and Prnp–PRNP polymorphic variation. We have previously used an in vitro conversion assay (PMCA) to investigate the susceptibility of the human PrP to conversion to its disease-associated form by several animal prion diseases, including CWD (15,16,22). The sensitivity of our molecular model for the detection of zoonotic conversion depends on the combination of 1) the action of proteinase K to degrade the abundant human PrPC that constitutes the substrate while only N terminally truncating any human PrPres produced and 2) the presence of the 3F4 epitope on human but not cervid PrP. In effect, this degree of sensitivity means that any human PrPres formed during the PMCA reaction can be detected down to the limit of Western blot sensitivity. In contrast, if other antibodies that detect both cervid and human PrP are used, such as 6H4, then newly formed human PrPres must be detected as a measurable increase in PrPres over the amount remaining in the reaction product from the cervid seed. Although best known for the efficient amplification of prions in research and diagnostic contexts, the variation of the PMCA method employed in our study is optimized for the definitive detection of zoonotic reaction products of inherently inefficient conversion reactions conducted across species barriers. By using this system, we previously made and reported the novel observation that elk CWD prions could convert human PrPC from human brain and could also convert recombinant human PrPC expressed in transgenic mice and eukaryotic cell cultures (15).
A previous publication suggested that mule deer PrPSc was unable to convert humanized transgenic substrate in PMCA assays (23) and required a further step of in vitro conditioning in deer substrate PMCA before it was able to cross the deer–human molecular barrier (24). However, prions from other species, such as elk (15) and reindeer affected by CWD, appear to be compatible with the human protein in a single round of amplification (as shown in our study). These observations suggest that different deer species affected by CWD could present differing degrees of the olecular compatibility with the normal form of human PrP.
The contribution of the polymorphism at codon 129 of the human PrP gene has been extensively studied and is recognized as a risk factor for Creutzfeldt-Jakob disease (4). In cervids, the equivalent codon corresponds to the position 132 encoding methionine or leucine. This polymorphism in the elk gene has been shown to play an important role in CWD susceptibility (25,26). We have investigated the effect of this cervid Prnp polymorphism on the conversion of the humanized transgenic substrate according to the variation in the equivalent PRNP codon 129 polymorphism. Interestingly, only the homologs methionine homozygous seed–substrate reactions could readily convert the human PrP, whereas the heterozygous elk PrPSc was unable to do so, even though comparable amounts of PrPres were used to seed the reaction. In addition, we observed only low levels of human PrPres formation in the reactions seeded with the homozygous methionine (132 MM) and the heterozygous (132 ML) seeds incubated with the other 2 human polymorphic substrates (129 MV and 129 VV). The presence of the amino acid leucine at position 132 of the elk Prnp gene has been attributed to a lower degree of prion conversion compared with methionine on the basis of experiments in mice made transgenic for these polymorphic variants (26). Considering the differences observed for the amplification of the homozygous human methionine substrate by the 2 polymorphic elk seeds (MM and ML), reappraisal of the susceptibility of human PrPC by the full range of cervid polymorphic variants affected by CWD would be warranted.
In light of the recent identification of the first cases of CWD in Europe in a free-ranging reindeer (R. tarandus) in Norway (2), we also decided to evaluate the in vitro conversion potential of CWD in 2 experimentally infected reindeer (18). Formation of human PrPres was readily detectable after a single round of PMCA, and in all 3 humanized polymorphic substrates (MM, MV, and VV). This finding suggests that CWD prions from reindeer could be more compatible with human PrPC generally and might therefore present a greater risk for zoonosis than, for example, CWD prions from white-tailed deer. A more comprehensive comparison of CWD in the affected species, coupled with the polymorphic variations in the human and deer PRNP–Prnp genes, in vivo and in vitro, will be required before firm conclusions can be drawn. Analysis of the Prnp sequence of the CWD reindeer in Norway was reported to be identical to the specimens used in our study (2). This finding raises the possibility of a direct comparison of zoonotic potential between CWD acquired in the wild and that produced in a controlled laboratory setting. (Table).
The prion hypothesis proposes that direct molecular interaction between PrPSc and PrPC is necessary for conversion and prion replication. Accordingly, polymorphic variants of the PrP of host and agent might play a role in determining compatibility and potential zoonotic risk. In this study, we have examined the capacity of the human PrPC to support in vitro conversion by elk, white-tailed deer, and reindeer CWD PrPSc. Our data confirm that elk CWD prions can convert the human PrPC, at least in vitro, and show that the homologous PRNP polymorphisms at codon 129 and 132 in humans and cervids affect conversion efficiency. Other species affected by CWD, particularly caribou or reindeer, also seem able to convert the human PrP. It will be important to determine whether other polymorphic variants found in other CWD-affected Cervidae or perhaps other factors (17) exert similar effects on the ability to convert human PrP and thus affect their zoonotic potential.
Dr. Barria is a research scientist working at the National CJD Research and Surveillance Unit, University of Edinburgh. His research has focused on understanding the molecular basis of a group of fatal neurologic disorders called prion diseases.
Acknowledgments We thank Aru Balachandran for originally providing cervid brain tissues, Abigail Diack and Jean Manson for providing mouse brain tissue, and James Ironside for his critical reading of the manuscript at an early stage.
This report is independent research commissioned and funded by the United Kingdom’s Department of Health Policy Research Programme and the Government of Scotland. The views expressed in this publication are those of the authors and not necessarily those of the Department of Health or the Government of Scotland.
Author contributions: The study was conceived and designed by M.A.B. and M.W.H. The experiments were conducted by M.A.B. and A.L. Chronic wasting disease brain specimens were provided by G.M. The manuscript was written by M.A.B. and M.W.H. All authors contributed to the editing and revision of the manuscript.
Prion 2017 Conference Abstracts
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress
Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1 University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen
This is a progress report of a project which started in 2009. 21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves. Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice. At present, a total of 10 animals are sacrificed and read-outs are ongoing. Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10years. Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation.
Czub S (2017) First evidence of intracranial and peroral transmission of chronic wasting disease (CWD) into Cynomolgus macaques: A work in progress. (Abstract) from Prion 2017, held in Edinburgh, Scotland, May 23–26.
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS ABSTRACTS REFERENCE
EFSA Panel on Biological Hazards (BIOHAZ) Antonia Ricci Ana Allende Declan Bolton Marianne Chemaly Robert Davies Pablo Salvador Fernández Escámez ...
First published: 17 January 2018 https://doi.org/10.2903/j.efsa.2018.5132
also, see;
8. Even though human TSE‐exposure risk through consumption of game from European cervids can be assumed to be minor, if at all existing, no final conclusion can be drawn due to the overall lack of scientific data.
***> In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison.
The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids. It might be prudent considering appropriate measures to reduce such a risk, e.g. excluding tissues such as CNS and lymphoid tissues from the human food chain, which would greatly reduce any potential risk for consumers.. However, it is stressed that currently, no data regarding a risk of TSE infections from cervid products are available.
https://efsa.onlinelibrary.wiley.com/doi/full/10.2903/j.efsa.2018.5132
2004
Jeff Swann and his Mom, cwd link... sporadic CJD?, CBC NEWS Jeff Schwan sCJD, CWD, and Professor Aguzzi on BSE and sporadic CJD
????: CBCnews
https://histodb15.usz.ch/pages/Images/videos/video-004/video-004.html
2004
April 22, 2004, 10:30 AM CDT Guests: Patrick Singh, Terry Schwan, Janet Skarbek, Bill Fielding (BEGIN VIDEOTAPE) ANNOUNCER: DEBORAH NORVILLE TONIGHT.
https://www.nbcnews.com/id/wbna4806886
1997-11-10: Panorama - The British disease
https://histodb15.usz.ch/pages/Images/videos/video-009/video-009.html
TUESDAY, MAY 11, 2021
A Unique Presentation of Creutzfeldt-Jakob Disease in a Patient Consuming Deer Antler Velvet <
Conclusion
We believe that our patient’s case of CJD is highly suspicious for cervid etiology given the circumstances of the case as well as the strong evidence of plausibility reported in published literature. This is the first known case of CJD in a patient who had consumed deer antler velvet. Despite the confirmed diagnosis of CJD, a causal relationship between the patient’s disease and his consumption of deer antler velvet cannot be definitively concluded.
Supplemental data including molecular tissue sample analysis and autopsy findings could yield further supporting evidence. Given this patient’s clinical resemblance to CBD and the known histological similarities of CBD with CJD, clinicians should consider both diseases in the differential diagnosis of patients with a similarly esoteric presentation. Regardless of the origin of this patient’s disease, it is clear that the potential for prion transmission from cervids to humans should be further investigated by the academic community with considerable urgency.
https://thescipub.com/pdf/ajidsp.2021.43.48.pdf
''We believe that our patient’s case of CJD is highly suspicious for cervid etiology given the circumstances of the case as well as the strong evidence of plausibility reported in published literature. This is the first known case of CJD in a patient who had consumed deer antler velvet. Despite the confirmed diagnosis of CJD, a causal relationship between the patient’s disease and his consumption of deer antler velvet cannot be definitively concluded.''
https://thescipub.com/pdf/ajidsp.2021.43.48.pdf
CREUTZFELDT JAKOB DISEASE: A Unique Presentation of Creutzfeldt-Jakob Disease in a Patient Consuming Deer Antler Velvet
i was warning England and the BSE Inquiry about just this, way back in 1998, and was ask to supply information to the BSE Inquiry. for anyone that might be interested, see;
Singeltary submission to the BSE Inquiry on CJD and Nutritional Supplements 1998
ABOUT that deer antler spray and CWD TSE PRION... I have been screaming this since my neighbors mom died from cjd, and she had been taking a supplement that contained bovine brain, bovine eyeball, and other SRMs specified risk materials, the most high risk for mad cow disease. just saying...
I made a submission to the BSE Inquiry long ago during the BSE Inquiry days, and they seemed pretty interested.
Sender: "Patricia Cantos"
To: "Terry S Singeltary Sr. (E-mail)"
Subject: Your submission to the Inquiry
Date: Fri, 3 Jul 1998 10:10:05 +0100 3 July 1998
Mr Terry S Singeltary Sr. E-Mail: Flounder at wt.net Ref: E2979
Dear Mr Singeltary, Thank you for your E-mail message of the 30th of June 1998 providing the Inquiry with your further comments. Thank you for offering to provide the Inquiry with any test results on the nutritional supplements your mother was taking before she died. As requested I am sending you our general Information Pack and a copy of the Chairman's letter. Please contact me if your system cannot read the attachments. Regarding your question, the Inquiry is looking into many aspects of the scientific evidence on BSE and nvCJD.
I would refer you to the transcripts of evidence we have already heard which are found on our internet site at ;
http://www.bse.org.uk.
Could you please provide the Inquiry with a copy of the press article you refer to in your e-mail? If not an approximate date for the article so that we can locate it? In the meantime, thank you for you comments. Please do not hesitate to contact me on... snip...end...tss
everyone I tell this too gets it screwed up...MY MOTHER WAS NOT TAKING THOSE SUPPLEMENTS IPLEX (that I ever knew of). this was my neighbors mother that died exactly one year previously and to the day of sporadic CJD that was diagnosed as Alzheimer’s at first. my mother died exactly a year later from the Heidenhain Variant of Creutzfeldt Jakob Disease hvCJD, and exceedingly rare strains of the ever growing sporadic CJD’s. both cases confirmed. ...
kind regards, terry
TSEs i.e. mad cow disease's BSE/BASE and NUTRITIONAL SUPPLEMENTS IPLEX, mad by standard process; vacuum dried bovine BRAIN, bone meal, bovine EYE, veal Bone, bovine liver powder, bovine adrenal, vacuum dried bovine kidney, and vacuum dried porcine stomach. also; what about potential mad cow candy bars ? see their potential mad cow candy bar list too... THESE are just a few of MANY of just this ONE COMPANY...TSS
https://wwwnc.cdc.gov/eid/article/15/5/08-1458_article
http://www.spiegel.de/spiegel/print/d-18578755.html
http://web.archive.org/web/20120325051946/http://www.spiegel.de/spiegel/print/d-18578755.html
http://chronic-wasting-disease.blogspot.com/2009/03/chronic-wasting-disease-prions-in-elk.html
http://creutzfeldt-jakob-disease.blogspot.com/2013/11/large-cjd-tse-prion-potential-case.html
http://tseac.blogspot.com/2011/02/usa-50-state-bse-mad-cow-conference.html
Two Hunters from the Same Lodge Afflicted with Sporadic CJD: Is Chronic Wasting Disease to Blame?
(P7-13.002) Jonathan Trout, Matthew Roberts, Michel Tabet, Eithan Kotkowski, and Sarah HornAUTHORS INFO & AFFILIATIONS April 9, 2024 issue 102 (17_supplement_1) https://doi.org/10.1212/WNL.0000000000204407
Abstract Publication History Information & Authors Metrics & Citations Share Abstract
Objective:
This study presents a cluster of Creutzfeldt-Jakob disease (CJD) cases after exposure to chronic wasting disease (CWD)-infected deer, suggestive of potential prion transmission from CWD-infected deer to humans.
Background:
CJD is a rapidly progressive central nervous system disorder caused by misfolded prion proteins. CWD, a prion disease prevalent in North American deer, has raised concerns due to its possible link to CJD. Although no conclusive evidence of cross-species prion transmission exists, vigilance for such cases is crucial for public health.
Design/Methods:
Not applicable.
Results:
In 2022, a 72-year-old man with a history of consuming meat from a CWD-infected deer population presented with rapid-onset confusion and aggression. His friend, who had also eaten venison from the same deer population, recently died of CJD, raising concerns about a potential link between CWD and human prion disease. Despite aggressive symptomatic treatment of seizures and agitation, the patient’s condition deteriorated and he died within a month of initial presentation. The diagnosis was confirmed postmortem as sporadic CJD with homozygous methionine at codon 129 (sCJDMM1). The patient’s history, including a similar case in his social group, suggests a possible novel animal-to-human transmission of CWD. Based on non-human primate and mouse models, cross-species transmission of CJD is plausible. Due to the challenge of distinguishing sCJDMM1 from CWD without detailed prion protein characterization, it is not possible to definitively rule out CWD in these cases. Although causation remains unproven, this cluster emphasizes the need for further investigation into the potential risks of consuming CWD-infected deer and its implications for public health.
Conclusions:
Clusters of sporadic CJD cases may occur in regions with CWD-confirmed deer populations, hinting at potential cross-species prion transmission. Surveillance and further research are essential to better understand this possible association.
Disclosure: Mr. Trout has nothing to disclose. Dr. Roberts has nothing to disclose. Dr. Tabet has nothing to disclose. Dr. Kotkowski has nothing to disclose. Dr. Horn has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Cala Trio. The institution of Dr. Horn has received research support from Alzheimer's Association.
https://www.neurology.org/doi/abs/10.1212/WNL.0000000000204407
http://chronic-wasting-disease.blogspot.com/2009/03/chronic-wasting-disease-prions-in-elk.html
http://creutzfeldt-jakob-disease.blogspot.com/2013/11/large-cjd-tse-prion-potential-case.html
http://tseac.blogspot.com/2011/02/usa-50-state-bse-mad-cow-conference.html
Two Hunters from the Same Lodge Afflicted with Sporadic CJD: Is Chronic Wasting Disease to Blame?
(P7-13.002) Jonathan Trout, Matthew Roberts, Michel Tabet, Eithan Kotkowski, and Sarah HornAUTHORS INFO & AFFILIATIONS April 9, 2024 issue 102 (17_supplement_1) https://doi.org/10.1212/WNL.0000000000204407
Abstract Publication History Information & Authors Metrics & Citations Share Abstract
Objective:
This study presents a cluster of Creutzfeldt-Jakob disease (CJD) cases after exposure to chronic wasting disease (CWD)-infected deer, suggestive of potential prion transmission from CWD-infected deer to humans.
Background:
CJD is a rapidly progressive central nervous system disorder caused by misfolded prion proteins. CWD, a prion disease prevalent in North American deer, has raised concerns due to its possible link to CJD. Although no conclusive evidence of cross-species prion transmission exists, vigilance for such cases is crucial for public health.
Design/Methods:
Not applicable.
Results:
In 2022, a 72-year-old man with a history of consuming meat from a CWD-infected deer population presented with rapid-onset confusion and aggression. His friend, who had also eaten venison from the same deer population, recently died of CJD, raising concerns about a potential link between CWD and human prion disease. Despite aggressive symptomatic treatment of seizures and agitation, the patient’s condition deteriorated and he died within a month of initial presentation. The diagnosis was confirmed postmortem as sporadic CJD with homozygous methionine at codon 129 (sCJDMM1). The patient’s history, including a similar case in his social group, suggests a possible novel animal-to-human transmission of CWD. Based on non-human primate and mouse models, cross-species transmission of CJD is plausible. Due to the challenge of distinguishing sCJDMM1 from CWD without detailed prion protein characterization, it is not possible to definitively rule out CWD in these cases. Although causation remains unproven, this cluster emphasizes the need for further investigation into the potential risks of consuming CWD-infected deer and its implications for public health.
Conclusions:
Clusters of sporadic CJD cases may occur in regions with CWD-confirmed deer populations, hinting at potential cross-species prion transmission. Surveillance and further research are essential to better understand this possible association.
Disclosure: Mr. Trout has nothing to disclose. Dr. Roberts has nothing to disclose. Dr. Tabet has nothing to disclose. Dr. Kotkowski has nothing to disclose. Dr. Horn has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Cala Trio. The institution of Dr. Horn has received research support from Alzheimer's Association.
https://www.neurology.org/doi/abs/10.1212/WNL.0000000000204407
THE FEAST!
-------- Original Message --------
Subject: Wild game feasts and fatal degenerative neurologic illness [CMAJ • September 2, 20030
Date: Mon, 06 Oct 2003 14:17:55 -0500
From: "Terry S. Singeltary Sr." To: BSE-L CC: CJDVoice , bloodcjd@yahoogroups.com
CMAJ • September 2, 2003; 169 (5) © 2003 Canadian Medical Association or its licensors
------------------------------------------------------------------------
PRACTICE
PUBLIC HEALTH
Wild game feasts and fatal degenerative neurologic illness
John Hoey
CMAJ
Background and epidemiology: Creutzfeldt–Jakob disease (CJD) is one of a group of conditions known as prion diseases that are caused by abnormally configured host-encoded prion proteins that accumulate in central nervous system tissue. There are 3 forms: sporadic, genetically determined and, more recently, variant CJD, acquired by infection when the disease crosses the species barrier between humans and cattle.1 A similar prion disease in deer and elk known as chronic wasting disease (CWD) has raised concerns that this prion could also cross species barriers in people who eat wild game.
Figure. Photo by: Chronic Wasting Disease Alliance
A report was recently published describing 3 cases of CWD in men who had attended wild game feasts.2
In the first case, a 66-year-old man who had been a lifelong hunter and who ate venison frequently had hosted wild game feasts at his cabin in Montana for 26 years before he died in 1992 of an autopsy-confirmed subacute spongiform encephalopathy compatible with CJD. He had a history of seizures since the age of 43 and had sought treatment for recurring seizures, increasing forgetfulness and worsening hand tremors about a month before he died.
The 2 other cases involved men aged 55 and 65 who died of neurologic illness. These men had histories of eating venison and participating in 1 or more of the first patient's wild game feasts. The younger man presented in 1999 with a 3-month history of difficulty in writing and unsteadiness of gait, followed by dementia, speech abnormalities and myoclonic jerking. Pathologic examination of the brain at autopsy 3 months later revealed widespread subcortical spongiform lesions consistent with CJD. He had visited the first patient's cabin 12 times and had participated in 1 wild game feast.
The older man sought treatment in 1992 for progressive slowing of speech, worsening memory and personality changes. His speech became reduced to single-word utterances, and he died 10 months after initial presentation. He had been a lifelong hunter and had hunted mostly in Wisconsin but also in Wyoming and British Columbia. He had participated regularly in the first patient's wild game feasts. No game had been brought to the wild game feasts from his hunting trips outside of Wisconsin.
Testing of fixed brain tissue from all 3 men revealed no evidence on immunostaining for prions using antibodies to the prion protein in the first and third patients. In the second patient prion disease was confirmed by means of immunohistochemical and Western blot testing. The blot characteristics and prion disease phenotype were consistent with the common form of sporadic CJD, classified as M/M (M/V) 1. Subsequent genetic typing revealed methionine homozygosity (M/M) at codon 129 of the patient's prion protein gene, making it likely that the patient had the most common form of sporadic CJD.
Information obtained for 45 people of 53 identified as possibly participating in the wild game feasts revealed that only 34 had actually attended them. Of the 34, 7 were dead, including the 3 described here; none of the other 4 had died of a degenerative neurologic disorder. None of the living participants had any signs or symptoms consistent with a degenerative neurologic disorder.
Clinical management: Because of the continuing possibility that CWD in deer and elk might be transmissible to humans, physicians should attempt to confirm cases of illness compatible with a transmissible spongiform encephalopathy through pathological examination of brain tissue and by alerting the Canadian CJD surveillance unit (www.hc-sc.gc.ca/pphb-dgspsp/hcai-iamss/cjd-mcj ; tel 888 489-2999) or the US National Prion Disease Pathology Surveillance Center (www.cjdsurveillance.com ). There is no known treatment for the condition.
Prevention: CWD was first identified in the United States in 1967. In Canada, only 8 cases of CWD have been reported in wild deer, all in Saskatchewan. In the United States, CWD has been found in free-ranging deer and elk in Illinois, Nebraska, New Mexico, South Dakota, Wisconsin, Colorado and Wyoming. Limited epidemiologic investigations to date cannot exclude the possibility that CWD may cause human disease. Because of the severity of the spongiform encephalopathies in humans and the absence of treatment, animals with evidence of CWD should be excluded from human and animal food chains.
John Hoey CMAJ
References
1. Coulthart MB, Cashman NR. Variant Creutzfeldt– Jakob disease: a summary of current scientific knowledge in relation to public health. CMAJ 2001; 165(1):51-8.[Abstract/Free Full Text]
2. Fatal degenerative neurologic illnesses in men who participated in wild game feasts — Wisconsin, 2002. MMWR Morb Mortal Wkly Rep 2003;52(7):125-7.[Medline]
Exposure Risk of Chronic Wasting Disease in Humans
by Satish K. Nemani 1,2,Jennifer L. Myskiw 3,4,Lise Lamoureux 3,Stephanie A. Booth 3,4 andValerie L. Sim 1,2,*OrcID
1 Centre for Prions and Protein Folding Diseases, Edmonton, AB T6G 2R3, Canada
2 Department of Medicine, Division of Neurology, University of Alberta, Edmonton, AB T6G 2R3, Canada
3 Zoonotic Diseases and Special Pathogens, Public Health Agency of Canada, National Microbiology Laboratory, Winnipeg, MB R3E 3R2, Canada
4 Department of Medical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 3R2, Canada
* Author to whom correspondence should be addressed. Academic Editor: Byron Caughey Viruses 2020, 12(12), 1454; https://doi.org/10.3390/v12121454 Received: 1 December 2020 / Revised: 14 December 2020 / Accepted: 15 December 2020 / Published: 17 December 2020 (This article belongs to the Special Issue The Future of the Chronic Wasting Disease Epizootic) View Full-Text Download PDF Browse Figures Review Reports Cite This Paper
Abstract
The majority of human prion diseases are sporadic, but acquired disease can occur, as seen with variant Creutzfeldt–Jakob disease (vCJD) following consumption of bovine spongiform encephalopathy (BSE). With increasing rates of cervid chronic wasting disease (CWD), there is concern that a new form of human prion disease may arise. Currently, there is no evidence of transmission of CWD to humans, suggesting the presence of a strong species barrier; however, in vitro and in vivo studies on the zoonotic potential of CWD have yielded mixed results. The emergence of different CWD strains is also concerning, as different strains can have different abilities to cross species barriers. Given that venison consumption is common in areas where CWD rates are on the rise, increased rates of human exposure are inevitable. If CWD was to infect humans, it is unclear how it would present clinically; in vCJD, it was strain-typing of vCJD prions that proved the causal link to BSE. Therefore, the best way to screen for CWD in humans is to have thorough strain-typing of harvested cervids and human CJD cases so that we will be in a position to detect atypical strains or strain shifts within the human CJD population.
View Full-Text
Keywords: chronic wasting disease (CWD); zoonotic potential; bovine spongiform encephalopathy (BSE); variant Creutzfeldt–Jakob disease (vCJD); sporadic CJD; CWD prions (PrPCWD); proteinase K resistant prion protein (PK-resPrP); strains; PRNP polymorphism; 129M/V polymorphism
snip...
5.3. Human Data There are no documented case reports of CWD transmission to humans.
The largest exposure occurred at a sportsman feast in Oneida county, NY, where 200 people were unknowingly exposed to CWD-infected venison meat. No cases of CJD were reported after 6 years of follow-up with 81 participants [73]. Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: Risk behaviours and health outcomes 2005–2011. Public Health 2014, 128, 860–868.
Other reports have tried to link cases of CJD with venison exposure, but proof of exposure to CWD is lacking in most cases. From 1997 to 1990, there were reports on the deaths of three unusually young people diagnosed with CJD who had a history of regular consumption of deer or elk meat [74].
Subsequently there were reports on the diagnosis of CJD in hunters who participated in wild game feast in Wisconsin (CDC 2003 report), detection of CJD in Colorado in a 52-year-old woman who had a CWD laboratory exposure, and a 25-year-old man with CJD who had consumed venison meat in a CWD endemic area [75]. In all the above studies, patients had PRNP genotypes, PrPD biochemical characteristics and pathologies suggestive of sporadic CJD. A subsequent study from Colorado demonstrated no statistically significant increase in CJD cases within CWD-endemic areas [76].
snip...see full text;
https://www.mdpi.com/1999-4915/12/12/1454
The largest exposure occurred at a sportsman feast in Oneida county, NY, where 200 people were unknowingly exposed to CWD-infected venison meat. No cases of CJD were reported after 6 years of follow-up with 81 participants [73]. Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: Risk behaviours and health outcomes 2005–2011. Public Health 2014, 128, 860–868...
A FURTHER REVEIW OF THIS SHOWS THAT ACTUALLY THERE WERE MEN THAT PARTICIPATED IN THIS FEAST THAT DID DIE OF A TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION DISEASE, 3 MEN THAT WERE REPORTED, YOU CAN SEE THIS HERE;
Fatal Degenerative Neurologic Illnesses in Men Who Participated in Wild Game Feasts --- Wisconsin, 2002
Creutzfeldt-Jakob disease (CJD) is a fatal neurologic disorder in humans. CJD is one of a group of conditions known as transmissible spongiform encephalopathies (TSEs), or prion diseases, that are believed to be caused by abnormally configured, host-encoded prion proteins that accumulate in the central nervous tissue
(1). CJD has an annual incidence of approximately 1 case per million population in the United States (1) and occurs in three forms: sporadic, genetically determined, and acquired by infection. In the latter form, the incubation period is measured typically in years. Recent evidence that prion infection can cross the species barrier between humans and cattle has raised increasing public health concerns about the possible transmission to humans of a TSE among deer and elk known as chronic wasting disease (CWD)
(2). During 1993--1999, three men who participated in wild game feasts in northern Wisconsin died of degenerative neurologic illnesses. This report documents the investigation of these deaths, which was initiated in August 2002 and which confirmed the death of only one person from CJD. Although no association between CWD and CJD was found, continued surveillance of both diseases remains important to assess the possible risk for CWD transmission to humans.
Case Reports
Case 1. In December 1992, a Wisconsin man aged 66 years with a history of seizures since 1969 sought treatment for recurring seizures, increasing forgetfulness, and worsening hand tremors. Electroencephalographic (EEG) examination demonstrated focal epileptiform activity and nonspecific diffuse abnormalities, but no specific diagnosis was made. In February 1993, he was hospitalized for increasing confusion, ataxia, and movement tremors of his extremities. A magnetic resonance image (MRI) demonstrated mild, nonspecific enhancement along the inferior parasagittal occipital lobe. A repeat EEG showed bifrontal intermittent, short-interval, periodic sharp waves, suggesting a progressive encephalopathy; a diagnosis of CJD was suspected. The man died later that month; neuropathologic examination of brain tissue during autopsy indicated subacute spongiform encephalopathy, compatible with CJD.
The man was a lifelong hunter who ate venison frequently. He hunted primarily in northern Wisconsin but also at least once in Montana. He hosted wild game feasts at his cabin in northern Wisconsin from 1976 until shortly before his death. Fixed brain tissue obtained during the autopsy was sent for analysis to the National Prion Disease Pathology Surveillance Center (NPDPSC) and reexamined at the institution where the autopsy was conducted. Histopathologic examination did not substantiate the diagnosis of prion disease. In addition, 27 brain tissue sections were negative for prions by immunostaining despite positive antibody reactions against other proteins (controls), which indicated that other epitopes in the tissue samples were preserved.
Case 2. In May 1999, a Minnesota man aged 55 years with no previous history of a neurologic disease sought evaluation and treatment following a 3-month history of progressive difficulty in writing and unsteadiness of gait. A computerized tomography (CT) scan and MRI examination of his head did not indicate any abnormality. In June 1999, he was hospitalized following onset of dementia, speech abnormalities, and myoclonic jerking. An EEG indicated left-hemispheric periodic sharp waves and moderate generalized background slowing; CJD was diagnosed clinically. In July 1999, following worsening symptoms and development of right upper extremity dystonia, the patient died. Neuropathologic evaluation of brain tissue during autopsy demonstrated widespread subcortical spongiform lesions, consistent with CJD.
The man was not a hunter but had a history of eating venison. He made an estimated 12 visits to the cabin where the wild game feasts were held, but he participated in only one feast during the mid-1980s. Sections of fixed and frozen brain tissue obtained during autopsy were analyzed at NPDPSC, and prion disease was confirmed by immunohistochemical and Western blot testing. The Western blot characteristics and prion disease phenotype in this patient were consistent with the most common form of sporadic CJD, classified as M/M (M/V) 1 (3). Subsequent genetic typing confirmed the presence of methionine homozygosity (M/M) at codon 129 of the patient's prion protein gene.
Case 3. In June 1992, a Wisconsin man aged 65 years sought treatment for progressive slowing of speech, worsening memory, and personality changes. By January 1993, his speech was reduced to one-word utterances. Neurologic examination showed a flat affect, decreased reflexes, and apraxia. A CT head scan showed mild atrophy, and an EEG was normal. Pick's disease was diagnosed. By May, he was unable to perform any daily living activities; he died in August 1993. Neuropathologic evaluation of brain tissue during autopsy showed symmetrical frontal lobe cerebral cortical atrophy and mild temporal lobe atrophy. No Pick's bodies or spongiform lesions were observed.
The man had a history of eating venison and participated regularly in wild game feasts held at the cabin owned by patient 1. He was a lifelong hunter and hunted mostly in Wisconsin but also in Wyoming and British Columbia. No game was brought to the wild game feasts from his hunting trips outside of Wisconsin. Examination of fixed brain tissue sent to NPDPSC demonstrated no lesions indicative of CJD, and immunohistochemical testing with antibody to the prion protein did not demonstrate the granular deposits seen in prion diseases.
https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5207a1.htm
The man whose disease was found to be CJD was a Minnesotan who died in 1999, the report says. He had visited the Wisconsin cabin about a dozen times but had eaten wild game only once. Analysis of his brain tissue suggested that his disease was the most common form of sporadic CJD, "without apparent unusual neruopathologic or molecular characteristics that might occur if the prion related to CWD had been responsible for the disease," the CDC said.
https://www.cidrap.umn.edu/news-perspective/2003/02/cdc-finds-no-cwd-cjd-link-wisconsin-deaths
by Satish K. Nemani 1,2,Jennifer L. Myskiw 3,4,Lise Lamoureux 3,Stephanie A. Booth 3,4 andValerie L. Sim 1,2,*OrcID
1 Centre for Prions and Protein Folding Diseases, Edmonton, AB T6G 2R3, Canada
2 Department of Medicine, Division of Neurology, University of Alberta, Edmonton, AB T6G 2R3, Canada
3 Zoonotic Diseases and Special Pathogens, Public Health Agency of Canada, National Microbiology Laboratory, Winnipeg, MB R3E 3R2, Canada
4 Department of Medical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 3R2, Canada
* Author to whom correspondence should be addressed. Academic Editor: Byron Caughey Viruses 2020, 12(12), 1454; https://doi.org/10.3390/v12121454 Received: 1 December 2020 / Revised: 14 December 2020 / Accepted: 15 December 2020 / Published: 17 December 2020 (This article belongs to the Special Issue The Future of the Chronic Wasting Disease Epizootic) View Full-Text Download PDF Browse Figures Review Reports Cite This Paper
Abstract
The majority of human prion diseases are sporadic, but acquired disease can occur, as seen with variant Creutzfeldt–Jakob disease (vCJD) following consumption of bovine spongiform encephalopathy (BSE). With increasing rates of cervid chronic wasting disease (CWD), there is concern that a new form of human prion disease may arise. Currently, there is no evidence of transmission of CWD to humans, suggesting the presence of a strong species barrier; however, in vitro and in vivo studies on the zoonotic potential of CWD have yielded mixed results. The emergence of different CWD strains is also concerning, as different strains can have different abilities to cross species barriers. Given that venison consumption is common in areas where CWD rates are on the rise, increased rates of human exposure are inevitable. If CWD was to infect humans, it is unclear how it would present clinically; in vCJD, it was strain-typing of vCJD prions that proved the causal link to BSE. Therefore, the best way to screen for CWD in humans is to have thorough strain-typing of harvested cervids and human CJD cases so that we will be in a position to detect atypical strains or strain shifts within the human CJD population.
View Full-Text
Keywords: chronic wasting disease (CWD); zoonotic potential; bovine spongiform encephalopathy (BSE); variant Creutzfeldt–Jakob disease (vCJD); sporadic CJD; CWD prions (PrPCWD); proteinase K resistant prion protein (PK-resPrP); strains; PRNP polymorphism; 129M/V polymorphism
snip...
5.3. Human Data There are no documented case reports of CWD transmission to humans.
The largest exposure occurred at a sportsman feast in Oneida county, NY, where 200 people were unknowingly exposed to CWD-infected venison meat. No cases of CJD were reported after 6 years of follow-up with 81 participants [73]. Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: Risk behaviours and health outcomes 2005–2011. Public Health 2014, 128, 860–868.
Other reports have tried to link cases of CJD with venison exposure, but proof of exposure to CWD is lacking in most cases. From 1997 to 1990, there were reports on the deaths of three unusually young people diagnosed with CJD who had a history of regular consumption of deer or elk meat [74].
Subsequently there were reports on the diagnosis of CJD in hunters who participated in wild game feast in Wisconsin (CDC 2003 report), detection of CJD in Colorado in a 52-year-old woman who had a CWD laboratory exposure, and a 25-year-old man with CJD who had consumed venison meat in a CWD endemic area [75]. In all the above studies, patients had PRNP genotypes, PrPD biochemical characteristics and pathologies suggestive of sporadic CJD. A subsequent study from Colorado demonstrated no statistically significant increase in CJD cases within CWD-endemic areas [76].
snip...see full text;
https://www.mdpi.com/1999-4915/12/12/1454
The largest exposure occurred at a sportsman feast in Oneida county, NY, where 200 people were unknowingly exposed to CWD-infected venison meat. No cases of CJD were reported after 6 years of follow-up with 81 participants [73]. Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: Risk behaviours and health outcomes 2005–2011. Public Health 2014, 128, 860–868...
A FURTHER REVEIW OF THIS SHOWS THAT ACTUALLY THERE WERE MEN THAT PARTICIPATED IN THIS FEAST THAT DID DIE OF A TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION DISEASE, 3 MEN THAT WERE REPORTED, YOU CAN SEE THIS HERE;
Fatal Degenerative Neurologic Illnesses in Men Who Participated in Wild Game Feasts --- Wisconsin, 2002
Creutzfeldt-Jakob disease (CJD) is a fatal neurologic disorder in humans. CJD is one of a group of conditions known as transmissible spongiform encephalopathies (TSEs), or prion diseases, that are believed to be caused by abnormally configured, host-encoded prion proteins that accumulate in the central nervous tissue
(1). CJD has an annual incidence of approximately 1 case per million population in the United States (1) and occurs in three forms: sporadic, genetically determined, and acquired by infection. In the latter form, the incubation period is measured typically in years. Recent evidence that prion infection can cross the species barrier between humans and cattle has raised increasing public health concerns about the possible transmission to humans of a TSE among deer and elk known as chronic wasting disease (CWD)
(2). During 1993--1999, three men who participated in wild game feasts in northern Wisconsin died of degenerative neurologic illnesses. This report documents the investigation of these deaths, which was initiated in August 2002 and which confirmed the death of only one person from CJD. Although no association between CWD and CJD was found, continued surveillance of both diseases remains important to assess the possible risk for CWD transmission to humans.
Case Reports
Case 1. In December 1992, a Wisconsin man aged 66 years with a history of seizures since 1969 sought treatment for recurring seizures, increasing forgetfulness, and worsening hand tremors. Electroencephalographic (EEG) examination demonstrated focal epileptiform activity and nonspecific diffuse abnormalities, but no specific diagnosis was made. In February 1993, he was hospitalized for increasing confusion, ataxia, and movement tremors of his extremities. A magnetic resonance image (MRI) demonstrated mild, nonspecific enhancement along the inferior parasagittal occipital lobe. A repeat EEG showed bifrontal intermittent, short-interval, periodic sharp waves, suggesting a progressive encephalopathy; a diagnosis of CJD was suspected. The man died later that month; neuropathologic examination of brain tissue during autopsy indicated subacute spongiform encephalopathy, compatible with CJD.
The man was a lifelong hunter who ate venison frequently. He hunted primarily in northern Wisconsin but also at least once in Montana. He hosted wild game feasts at his cabin in northern Wisconsin from 1976 until shortly before his death. Fixed brain tissue obtained during the autopsy was sent for analysis to the National Prion Disease Pathology Surveillance Center (NPDPSC) and reexamined at the institution where the autopsy was conducted. Histopathologic examination did not substantiate the diagnosis of prion disease. In addition, 27 brain tissue sections were negative for prions by immunostaining despite positive antibody reactions against other proteins (controls), which indicated that other epitopes in the tissue samples were preserved.
Case 2. In May 1999, a Minnesota man aged 55 years with no previous history of a neurologic disease sought evaluation and treatment following a 3-month history of progressive difficulty in writing and unsteadiness of gait. A computerized tomography (CT) scan and MRI examination of his head did not indicate any abnormality. In June 1999, he was hospitalized following onset of dementia, speech abnormalities, and myoclonic jerking. An EEG indicated left-hemispheric periodic sharp waves and moderate generalized background slowing; CJD was diagnosed clinically. In July 1999, following worsening symptoms and development of right upper extremity dystonia, the patient died. Neuropathologic evaluation of brain tissue during autopsy demonstrated widespread subcortical spongiform lesions, consistent with CJD.
The man was not a hunter but had a history of eating venison. He made an estimated 12 visits to the cabin where the wild game feasts were held, but he participated in only one feast during the mid-1980s. Sections of fixed and frozen brain tissue obtained during autopsy were analyzed at NPDPSC, and prion disease was confirmed by immunohistochemical and Western blot testing. The Western blot characteristics and prion disease phenotype in this patient were consistent with the most common form of sporadic CJD, classified as M/M (M/V) 1 (3). Subsequent genetic typing confirmed the presence of methionine homozygosity (M/M) at codon 129 of the patient's prion protein gene.
Case 3. In June 1992, a Wisconsin man aged 65 years sought treatment for progressive slowing of speech, worsening memory, and personality changes. By January 1993, his speech was reduced to one-word utterances. Neurologic examination showed a flat affect, decreased reflexes, and apraxia. A CT head scan showed mild atrophy, and an EEG was normal. Pick's disease was diagnosed. By May, he was unable to perform any daily living activities; he died in August 1993. Neuropathologic evaluation of brain tissue during autopsy showed symmetrical frontal lobe cerebral cortical atrophy and mild temporal lobe atrophy. No Pick's bodies or spongiform lesions were observed.
The man had a history of eating venison and participated regularly in wild game feasts held at the cabin owned by patient 1. He was a lifelong hunter and hunted mostly in Wisconsin but also in Wyoming and British Columbia. No game was brought to the wild game feasts from his hunting trips outside of Wisconsin. Examination of fixed brain tissue sent to NPDPSC demonstrated no lesions indicative of CJD, and immunohistochemical testing with antibody to the prion protein did not demonstrate the granular deposits seen in prion diseases.
https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5207a1.htm
The man whose disease was found to be CJD was a Minnesotan who died in 1999, the report says. He had visited the Wisconsin cabin about a dozen times but had eaten wild game only once. Analysis of his brain tissue suggested that his disease was the most common form of sporadic CJD, "without apparent unusual neruopathologic or molecular characteristics that might occur if the prion related to CWD had been responsible for the disease," the CDC said.
https://www.cidrap.umn.edu/news-perspective/2003/02/cdc-finds-no-cwd-cjd-link-wisconsin-deaths
SATURDAY, FEBRUARY 23, 2019
Chronic Wasting Disease CWD TSE Prion and THE FEAST 2003 CDC an updated review of the science 2019
TUESDAY, NOVEMBER 04, 2014
Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: risk behaviours and health outcomes 2005–2011
Authors, though, acknowledged the study was limited in geography and sample size and so it couldn't draw a conclusion about the risk to humans. They recommended more study. Dr. Ermias Belay was the report's principal author but he said New York and Oneida County officials are following the proper course by not launching a study. "There's really nothing to monitor presently. No one's sick," Belay said, noting the disease's incubation period in deer and elk is measured in years. "
*** now, let’s see what the authors said about this casual link, personal communications years ago, and then the latest on the zoonotic potential from CWD to humans from the TOKYO PRION 2016 CONFERENCE.
see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ????
“Our conclusion stating that we found no strong evidence of CWD transmission to humans”
From: TSS Subject: CWD aka MAD DEER/ELK TO HUMANS ???
Date: September 30, 2002 at 7:06 am PST
From: "Belay, Ermias"
To: Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"
Sent: Monday, September 30, 2002 9:22 AM
Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Dear Sir/Madam, In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD.. That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091).
Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.
Ermias Belay, M.D. Centers for Disease Control and Prevention
-----Original Message----- From:
Sent: Sunday, September 29, 2002 10:15 AM
To: rr26k@nih.gov; rrace@niaid.nih.gov; ebb8@CDC.GOV
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM .......snip........end..............TSS
Thursday, April 03, 2008
A prion disease of cervids: Chronic wasting disease 2008 1: Vet Res. 2008 Apr 3;39(4):41
see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ????
“Our conclusion stating that we found no strong evidence of CWD transmission to humans”
From: TSS Subject: CWD aka MAD DEER/ELK TO HUMANS ???
Date: September 30, 2002 at 7:06 am PST
From: "Belay, Ermias"
To: Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"
Sent: Monday, September 30, 2002 9:22 AM
Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Dear Sir/Madam, In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD.. That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091).
Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.
Ermias Belay, M.D. Centers for Disease Control and Prevention
-----Original Message----- From:
Sent: Sunday, September 29, 2002 10:15 AM
To: rr26k@nih.gov; rrace@niaid.nih.gov; ebb8@CDC.GOV
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM .......snip........end..............TSS
Thursday, April 03, 2008
A prion disease of cervids: Chronic wasting disease 2008 1: Vet Res. 2008 Apr 3;39(4):41
A prion disease of cervids: Chronic wasting disease Sigurdson CJ.
snip...
snip...
*** twenty-seven CJD patients who regularly consumed venison were reported to the Surveillance Center***,
snip... full text ;
http://chronic-wasting-disease.blogspot.com/2008/04/prion-disease-of-cervids-chronic.html
However, to date, no CWD infections have been reported in people.
sporadic, spontaneous CJD, 85%+ of all human TSE, did not just happen. never in scientific literature has this been proven. if one looks up the word sporadic or spontaneous at pubmed, you will get a laundry list of disease that are classified in such a way;
sporadic = 54,983 hits
https://www.ncbi.nlm.nih.gov/pubmed/?term=sporadic
spontaneous = 325,650 hits
https://www.ncbi.nlm.nih.gov/pubmed/?term=spontaneous
key word here is 'reported'. science has shown that CWD in humans will look like sporadic CJD.
SO, how can one assume that CWD has not already transmitted to humans? they can't, and it's as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it's being misdiagnosed as sporadic CJD. ...terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
However, to date, no CWD infections have been reported in people. key word here is ‘reported’. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can’t, and it’s as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it’s being misdiagnosed as sporadic CJD. …terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***
http://www.tandfonline.com/doi/full/10.4161/pri.28124?src=recsys
http://www.tandfonline.com/doi/pdf/10.4161/pri.28124?needAccess=true
https://wwwnc.cdc.gov/eid/article/20/1/13-0858_article
snip... full text ;
http://chronic-wasting-disease.blogspot.com/2008/04/prion-disease-of-cervids-chronic.html
However, to date, no CWD infections have been reported in people.
sporadic, spontaneous CJD, 85%+ of all human TSE, did not just happen. never in scientific literature has this been proven. if one looks up the word sporadic or spontaneous at pubmed, you will get a laundry list of disease that are classified in such a way;
sporadic = 54,983 hits
https://www.ncbi.nlm.nih.gov/pubmed/?term=sporadic
spontaneous = 325,650 hits
https://www.ncbi.nlm.nih.gov/pubmed/?term=spontaneous
key word here is 'reported'. science has shown that CWD in humans will look like sporadic CJD.
SO, how can one assume that CWD has not already transmitted to humans? they can't, and it's as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it's being misdiagnosed as sporadic CJD. ...terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
However, to date, no CWD infections have been reported in people. key word here is ‘reported’. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can’t, and it’s as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it’s being misdiagnosed as sporadic CJD. …terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***
http://www.tandfonline.com/doi/full/10.4161/pri.28124?src=recsys
http://www.tandfonline.com/doi/pdf/10.4161/pri.28124?needAccess=true
https://wwwnc.cdc.gov/eid/article/20/1/13-0858_article
2002
Date: Fri, 18 Oct 2002 23:12:22 +0100 Singeltary et al
“regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD”
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler
Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ …
######## Bovine Spongiform Encephalopathy <BSE-L@UNI-KARLSRUHE.DE> #########
Dear Terry,
An excellent piece of review as this literature is desparately difficult to get back from Government sites.
What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported.
Well, if you dont look adequately like they are in USA currenly then you wont find any!
Steve Dealler
########### http://mailhost.rz.uni-karlsruhe.de/warc/bse-l.html ############
Subject: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
From: "Terry S. Singeltary Sr." <flounder@WT.NET>
Reply To: Bovine Spongiform Encephalopathy <BSE-L@UNI-KARLSRUHE.DE>
Date: Thu, 17 Oct 2002 17:04:51 -0700
snip...
''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994
Consumption of venison and veal was much less widespread among both cases and controls. For both of these meats there was evidence of a trend with increasing frequency of consumption being associated with increasing risk of CJD. (not nvCJD, but sporadic CJD...tss) These associations were largely unchanged when attention was restricted to pairs with data obtained from relatives. ...
Table 9 presents the results of an analysis of these data.
There is STRONG evidence of an association between ‘’regular’’ veal eating and risk of CJD (p = .0.01).
Individuals reported to eat veal on average at least once a year appear to be at 13 TIMES THE RISK of individuals who have never eaten veal.
There is, however, a very wide confidence interval around this estimate. There is no strong evidence that eating veal less than once per year is associated with increased risk of CJD (p = 0.51).
The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).
There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02).
The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).
snip...
It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).
snip...
In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...
snip...
In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)
snip...see full report ;
http://web.archive.org/web/20090506050043/http://www.bseinquiry.gov.uk/files/yb/1994/08/00004001.pdf
http://web.archive.org/web/20090506050007/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
http://web.archive.org/web/20090506050244/http://www.bseinquiry.gov.uk/files/yb/1994/07/00001001.pdf
Stephen Dealler is a consultant medical microbiologist deal@airtime.co.uk
BSE Inquiry Steve Dealler
Management In Confidence
BSE: Private Submission of Bovine Brain Dealler
snip...end
########### http://mailhost.rz.uni-karlsruhe.de/warc/bse-l.html ############
BSE INQUIRY
CJD9/10022
October 1994
Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane
BerksWell Coventry CV7 7BZ
Dear Mr Elmhirst,
CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT
Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.
The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended.. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.
The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.
The statistical results reqarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.
I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.
http://web.archive.org/web/20030511010117/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
TSE in wild UK deer? The first case of BSE (as we now realise) was in a nyala in London zoo and the further zoo cases in ungulates were simply thought of as being interesting transmissions of scrapie initially. The big problem started to appear with animals in 1993-5 when it became clear that there was an increase in the CJD cases in people that had eaten deer although the statistics involved must have been questionable. The reason for this was that the CJD Surveillance was well funded to look into the diet of people dying of CJD. This effect is not clear with vCJD...if only because the numbers involved are much smaller and hence it is difficult to gain enough statistics. They found that many other foods did not appear to have much association at all but that deer certainly did and as years went by the association actually became clearer. The appearance of vCJD in 1996 made all this much more difficult in that it was suddenly clearer that the cases of sporadic CJD that they had been checking up until then probably had nothing to do with beef...and the study decreased. During the period there was an increasing worry that deer were involved with CJD..
see references:
DEER BRAIN SURVEY
https://web.archive.org/web/20090506025229/http://www.bseinquiry.gov.uk/files/yb/1991/11/20004001.pdf
CONFIDENTIAL AND IN CONFIDENCE TRANSMISSION TO CHIMPANZEES AND PIGS
IN CONFIDENCE
TRANSMISSION TO CHIMPANZEES
Kuru and CJD have been successfully transmitted to chimpanzees but scrapie and TME have not.
We cannot say that scrapie will not transmit to chimpanzees. There are several scrapie strains and I am not aware that all have been tried (that would have to be from mouse passaged material). Nor has a wide enough range of field isolates subsequently strain typed in mice been inoculated by the appropriate routes (i/c, i/p and i/v).
I believe the proposed experiment to determine transmissibility, if conducted, would only show the susceptibility or resistance of the chimpanzee to infection/disease by the routes used and the result could not be interpreted for the predictability of the susceptibility for man. proposals for prolonged oral exposure of chimpanzees to milk from cattle were suggested a long while ago and rejected.
In view of Dr Gibbs' probable use of chimpazees Mr Wells' comments (enclosed) are pertinent. I have yet to receive a direct communication from Dr Schellekers but before any collaboration or provision of material we should identify the Gibbs' proposals and objectives.
A positive result from a chimpanzee challenged severely would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
A negative result would take a lifetime to determine but that would be a shorter period than might be available for human exposure and it would still not answer the question regarding mans ‘susceptibility. In the meantime no doubt the negativity would be used defensively. It would however be counterproductive if the experiment finally became positive. We may learn more about public reactions following next Monday's meeting.
R Bradley
CVO (+ Mr Wells’ commenters 23 September 1990 Dr T W A Little Dr B J Shreeve
90/9.23/1.1
https://web.archive.org/web/20090506041740/http://www.bseinquiry.gov.uk/files/yb/1990/09/23001001.pdf
“regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD”
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler
Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ …
######## Bovine Spongiform Encephalopathy <BSE-L@UNI-KARLSRUHE.DE> #########
Dear Terry,
An excellent piece of review as this literature is desparately difficult to get back from Government sites.
What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported.
Well, if you dont look adequately like they are in USA currenly then you wont find any!
Steve Dealler
########### http://mailhost.rz.uni-karlsruhe.de/warc/bse-l.html ############
Subject: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
From: "Terry S. Singeltary Sr." <flounder@WT.NET>
Reply To: Bovine Spongiform Encephalopathy <BSE-L@UNI-KARLSRUHE.DE>
Date: Thu, 17 Oct 2002 17:04:51 -0700
snip...
''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994
Consumption of venison and veal was much less widespread among both cases and controls. For both of these meats there was evidence of a trend with increasing frequency of consumption being associated with increasing risk of CJD. (not nvCJD, but sporadic CJD...tss) These associations were largely unchanged when attention was restricted to pairs with data obtained from relatives. ...
Table 9 presents the results of an analysis of these data.
There is STRONG evidence of an association between ‘’regular’’ veal eating and risk of CJD (p = .0.01).
Individuals reported to eat veal on average at least once a year appear to be at 13 TIMES THE RISK of individuals who have never eaten veal.
There is, however, a very wide confidence interval around this estimate. There is no strong evidence that eating veal less than once per year is associated with increased risk of CJD (p = 0.51).
The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).
There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02).
The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).
snip...
It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).
snip...
In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...
snip...
In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)
snip...see full report ;
http://web.archive.org/web/20090506050043/http://www.bseinquiry.gov.uk/files/yb/1994/08/00004001.pdf
http://web.archive.org/web/20090506050007/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
http://web.archive.org/web/20090506050244/http://www.bseinquiry.gov.uk/files/yb/1994/07/00001001.pdf
Stephen Dealler is a consultant medical microbiologist deal@airtime.co.uk
BSE Inquiry Steve Dealler
Management In Confidence
BSE: Private Submission of Bovine Brain Dealler
snip...end
########### http://mailhost.rz.uni-karlsruhe.de/warc/bse-l.html ############
BSE INQUIRY
CJD9/10022
October 1994
Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane
BerksWell Coventry CV7 7BZ
Dear Mr Elmhirst,
CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT
Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.
The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended.. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.
The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.
The statistical results reqarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.
I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.
http://web.archive.org/web/20030511010117/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
TSE in wild UK deer? The first case of BSE (as we now realise) was in a nyala in London zoo and the further zoo cases in ungulates were simply thought of as being interesting transmissions of scrapie initially. The big problem started to appear with animals in 1993-5 when it became clear that there was an increase in the CJD cases in people that had eaten deer although the statistics involved must have been questionable. The reason for this was that the CJD Surveillance was well funded to look into the diet of people dying of CJD. This effect is not clear with vCJD...if only because the numbers involved are much smaller and hence it is difficult to gain enough statistics. They found that many other foods did not appear to have much association at all but that deer certainly did and as years went by the association actually became clearer. The appearance of vCJD in 1996 made all this much more difficult in that it was suddenly clearer that the cases of sporadic CJD that they had been checking up until then probably had nothing to do with beef...and the study decreased. During the period there was an increasing worry that deer were involved with CJD..
see references:
DEER BRAIN SURVEY
https://web.archive.org/web/20090506025229/http://www.bseinquiry.gov.uk/files/yb/1991/11/20004001.pdf
CONFIDENTIAL AND IN CONFIDENCE TRANSMISSION TO CHIMPANZEES AND PIGS
IN CONFIDENCE
TRANSMISSION TO CHIMPANZEES
Kuru and CJD have been successfully transmitted to chimpanzees but scrapie and TME have not.
We cannot say that scrapie will not transmit to chimpanzees. There are several scrapie strains and I am not aware that all have been tried (that would have to be from mouse passaged material). Nor has a wide enough range of field isolates subsequently strain typed in mice been inoculated by the appropriate routes (i/c, i/p and i/v).
I believe the proposed experiment to determine transmissibility, if conducted, would only show the susceptibility or resistance of the chimpanzee to infection/disease by the routes used and the result could not be interpreted for the predictability of the susceptibility for man. proposals for prolonged oral exposure of chimpanzees to milk from cattle were suggested a long while ago and rejected.
In view of Dr Gibbs' probable use of chimpazees Mr Wells' comments (enclosed) are pertinent. I have yet to receive a direct communication from Dr Schellekers but before any collaboration or provision of material we should identify the Gibbs' proposals and objectives.
A positive result from a chimpanzee challenged severely would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
A negative result would take a lifetime to determine but that would be a shorter period than might be available for human exposure and it would still not answer the question regarding mans ‘susceptibility. In the meantime no doubt the negativity would be used defensively. It would however be counterproductive if the experiment finally became positive. We may learn more about public reactions following next Monday's meeting.
R Bradley
CVO (+ Mr Wells’ commenters 23 September 1990 Dr T W A Little Dr B J Shreeve
90/9.23/1.1
https://web.archive.org/web/20090506041740/http://www.bseinquiry.gov.uk/files/yb/1990/09/23001001.pdf
HUMAN TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES: A CRITICAL SCIENTIFIC INVESTMENT
Final Report of the National Prion Research Program
US Army Medical Research and Materiel Command Congressionally Directed Medical Research Programs
Fort Detrick, Maryland
2007
Snip…
*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies.
Snip…
So, this is what we leave our children and grandchildren?
***> Creutzfeldt Jakob Disease CJD TSE Prion Cases Increasing March 2025
https://creutzfeldt-jakob-disease.blogspot.com/2025/03/creutzfeldt-jakob-disease-tse-prion.html
***> Creutzfeldt Jakob 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
https://creutzfeldt-jakob-disease.blogspot.com/
Iatrogenic Transmissible Spongiform Encephalopathy TSE Prion, CWD, our worst nightmare, what if?
https://itseprion.blogspot.com/
So, this is what we leave our children and grandchildren?
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
5:20 PM
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