Department for Environment, Food and Rural Affairs
Preliminary Outbreak Assessment
Chronic wasting disease prions in cervids and wild pigs in North America
26 January 2026
Disease report
Chronic wasting disease (CWD) is a fatal neurodegenerative disease of cervids, such as deer, elk, moose and reindeer. It is caused by prions – infectious proteins that cause normal cellular prion proteins to misfold (CIDRAP, 2025). The disease is widespread in captive and free-ranging cervids in North America (Figure 1). For the first time, CWD prions have also been detected in the tissues of wild pigs (Sus scrofa) caught in CWD-affected areas of the USA (Soto et al. 2025). This discovery emerged from a study designed to investigate potential interactions between wild pigs and CWD prions, as wild pigs often coexist with cervids, which can shed prions into the environment. The following assessment discusses the epidemiology of CWD in North America and the detection of CWD prions in wild pigs. It also considers the potential implications for Great Britain.
Figure 1. Distribution of CWD in cervids in North America as of 11 April 2025 (USGS, 2025).Department for Environment, Food and Rural Affairs
Situation assessment
CWD is considered one of the most important cervid diseases due to its capacity for infectious spread, high mortality rate and associated socio-economic impacts on cervid farming and hunting-related industries (Kincheloe et al., 2021, CFSPH, 2024). The disease is always fatal, with no cure or vaccine (CFSPH, 2024).
CWD was first reported among captive cervids in the USA in the 1960s (Kincheloe et al., 2021). It has since been detected in captive and or free-ranging cervids in 36 US states and 5 Canadian provinces, as well as South Korea, Norway, Finland and Sweden (Silva, 2022, USGS, 2025). While the South Korean strains are thought to have originated from North America, the European strains appear to have emerged independently (Silva, 2022).
Transmission between cervids occurs by direct contact with infected animals or indirectly, through contact with a contaminated environment, most likely via the oral route (Otero et al., 2021). The disease may also be vertically transmitted from doe to fawn (Nalls et al., 2013, Salariu et al., 2015). Environmental contamination occurs when infected animals shed infectious prions in various secretions and excretions, such as urine, faeces and saliva (Otero et al., 2021). It can also occur when infected carcasses decompose and release prions into the surrounding soil and vegetation (Miller et al., 2004). The minimum number of CWD prions required to cause infection in cervids is unknown but appears to be low (Denkers et al., 2020).
The disease is difficult to control, as infected animals can also be subclinical for months or years. During this time, they can shed CWD prions, which can remain infectious in the environment for at least 2 years (Miller et al., 2004, CFSPH, 2024). Diagnosis usually relies on post-mortem tests, which may fail to identify infected animals during the early stages of the disease (CFSPH, 2024, CIDRAP, 2025). Control efforts are further hampered by lack of evidence to inform effective CWD management and control strategies (Uehlinger et al., 2016, Mori et al., 2024).
CWD in North American cervids
CWD has been reported in a range of North American cervids, including white-tailed deer, mule deer, black-tailed deer, moose, wapiti, reindeer (captive) and red deer (captive) (EFSA BIOHAZ Panel, 2023). It was first reported in captive mule deer and black-tailed deer at research facilities in Colorado and Wyoming in the late 1960s (Otero et al., 2021). These animals were derived from wild populations. The disease was later identified in Rocky Mountain elk at these facilities and subsequently, in free-ranging populations of mule deer and elk in Wyoming and Colorado. The geographic expansion of CWD in North America is thought to reflect the commercial movement of subclinical animals and natural cervid migration (Otero et al., 2021). Epidemiological data suggest that the disease spread from the USA to Canada and then to South Korea through imports of infected cervids (Otero et al., 2021). A retrospective analysis revealed that, in 1978, a Colorado‑born mule deer at Toronto Zoo in Ontario, Canada, died of CWD (Dubé et al., 2006). In 1996, the disease was detected in captive elk in Saskatchewan (Williams and Miller, 2002).
The disease
Department for Environment, Food and Rural Affairs
has since been detected in captive cervids in Alberta and Quebec and free-ranging cervids in Alberta, British Columbia, Manitoba and Saskatchewan (USGS, 2025). The origin of the outbreak in free-ranging Canadian cervids is unknown (Otero et al., 2021).
While the spread of CWD across North America is often described as ‘rapid,’ it has been suggested that this may reflect widening disease surveillance, rather than a ‘real-time’ indication of geographic spread. CWD epidemics appear to develop relatively slowly compared with other wildlife diseases (EFSA BIOHAZ Panel, 2023). Field and modelling data from North America suggest that it may take 15 to 20 years for CWD prevalence to reach 1% in free-ranging cervid populations, although more rapid transmission may occur in captive populations. The surveillance sensitivity in North America means that the disease may have been present for 10 years or more in some areas before it was detected (Miller et al., 2000).
The prevalence of CWD in affected populations or species varies across North America. In captive herds, prevalence may reach 100% over time, while in affected free-ranging populations, reported prevalence ranges from <1% to >30%. Most clinical cases are observed in cervids 2 to 7 years old, especially males, which is believed to be due to behavioural differences rather than differences in susceptibility between sexes (EFSA BIOHAZ Panel, 2023). At least 13 different risk factors may contribute towards CWD spread in North America, such as host genetics, high deer density or inappropriate disposal of deer carcasses and slaughter by-products (EFSA BIOHAZ Panel, 2019).
Approaches towards CWD control and surveillance in captive and free-ranging deer vary widely across North America within and between jurisdictions (CIDRAP, 2025). A summary of the measures in place in each US state and Canadian province is available from the CWD Alliance (2026), a coalition of wildlife conservation agencies, dedicated to providing accurate information on CWD and supporting strategies to minimise its impact on free-ranging cervids. Wildlife agencies rely on voluntary testing of hunted deer carcasses as the main mechanism for CWD surveillance and management, usually using post-mortem ELISA or immunohistochemistry methods (CIDRAP, 2025).
In the USA, Animal and Plant Health Inspection Service (APHIS) operates the CWD Herd Certification Programme (HCP) in collaboration with state and wildlife agencies. This is a voluntary scheme which aims to provide a consistent, national approach to controlling CWD in farmed cervids and preventing interstate spread by establishing control measures such as fencing, detailed record keeping and CWD testing of all cervids over 12 months old that die for any reason. The Canadian Food Inspection Agency (CFIA) operates a similar programme, the CWD Herd Certification Programme. As of December 2025, 28 states were participating in the USA’s CWD HCP and 5 Canadian provinces and one Canadian territory were participating in the Canadian programme (USDA, 2025b, CFIA, 2025).
Control methods fall within three general categories: prevention, containment, and control and suppression. Prevention and containment aim to prevent CWDDepartment for Environment, Food and Rural Affairs introduction into areas where it has not previously been reported and to limit its geographical spread once it has been introduced, respectively. Both tend to include regulatory measures such as bans on the movement of live cervids, cervid carcasses or specified risk materials. Control and suppression aim to stabilise or reduce infection rates within a herd or population through measures such as selective or random culling (EFSA BIOHAZ Panel, 2017).
Despite control efforts, CWD has continued to spread among captive and free- ranging cervids in North America, with increasing prevalence in affected areas (Uehlinger et al., 2016, CFSPH, 2024). Eradicating CWD from North America appears infeasible due to its extent of geographic spread and epidemiological characteristics, such as environmental persistence (EFSA BIOHAZ Panel, 2017).
CWD in wild pigs in the USA
Wild pigs are an invasive population in the USA, especially in the south (Figure 2). They comprise escaped domestic swine, Eurasian wild boar and hybrids of the two (Smyser et al., 2020). Wild pigs frequently coexist with cervids in areas where CWD is endemic and may be exposed to CWD prions through rooting in contaminated soil, scavenging deer carcasses and predation on fawns. These ecological interactions provide multiple routes by which wild pigs could encounter prions from infected deer (Soto et al. 2025).
Under experimental conditions, domestic pigs can become infected with CWD by oral and intracerebral routes, suggesting that wild pigs might also be susceptible. Domestic pigs rarely develop clinical signs of CWD but accumulate prions in the lymphoid tissues in their heads and gut, suggesting that, like cervids, they could shed the prions in saliva and faeces (Moore et al., 2017).
Against this background, Soto et al. (2025) investigated potential interactions between wild pigs and CWD prions. They analysed over 300 brain and lymph node samples from 178 wild pigs living across Arkansas and Texas, USA. The animals were captured by the United States Department of Agriculture (USDA) between 2020 and 2021. None of the pigs included in the study were reported to be displaying clinical signs of disease.
Using an ultra-sensitive laboratory method (protein misfolding cyclic amplification (PMCA)), the researchers identified CWD prions in up to 37% of the lymph node samples and 15% of brain samples. The lowest detection rates were in the Texas samples (below 16%), matching the lower CWD prevalence in the state’s cervid population. These findings indicate that wild pigs are naturally exposed to CWD prions in areas where the disease is present (Soto et al., 2025).
When intracerebrally inoculated with tissues from wild pigs, a small proportion of mice expressing deer prion protein developed subclinical prion infection. No transmission was detected in mice expressing pig prion protein. This suggests that wild pig tissues only contain low levels of infectious prions and that wild pigs are relatively resistant to natural infection. However, they could still contribute to CWD transmission, influencing its epidemiology, geographic distribution and interspecies spread (Soto et al., 2025).Department for Environment, Food and Rural Affairs While their exact role and importance in CWD transmission is unclear, wild pigs have considerable home ranges in North America (1.1 to 5.32 km on average), which may increase when food is scarce. This mobility could complicate efforts to control the disease if they play a role in its transmission (Soto et al., 2025).
The USDA’s APHIS does not currently conduct active surveillance for CWD in wild pigs (USDA, 2025a).
Figure 2. Geographic distribution of wild pigs (purple) in the USA as of 27 January 2025, comprising escaped domestic pigs, Eurasian wild boar and hybrids of the two (adapted from USDA, 2026). Yellow (Texas) and green (Arkansas) circles indicate the states where CWD prions were detected in wild pig tissues.
Department for Environment, Food and Rural Affairs
Implications for Great Britain
CWD is a notifiable animal disease in Great Britain, but no cases have ever been reported (Defra and APHA, 2018, CIDRAP, 2025).
The introduction of CWD into Great Britain’s cervid population could have devastating socio-economic and animal welfare impacts, resulting in marked population declines, as seen in the USA (Miller et al., 2008). There could also be significant losses to cervid farming, hunting and rural tourism industries, as well as significant costs associated with controlling the spread of the disease. The UK venison market alone is worth an estimated £100 million (Scotland Food and Drink, 2018).
There are several discrete wild pig populations in Great Britain, including wild boar and feral pigs. The largest known population is in the Forest of Dean in Gloucestershire, with an estimated 583 wild boar as of 2025/2026, although Forestry England (2025) aims to reduce the number to 400 to protect other species, such as plants and insects. Pockets of wild boar and feral pigs exist in other parts of the country, but their exact numbers are unknown (Mathews et al., 2018). The potential impact of CWD introduction into Great Britain’s wild pig population is uncertain because their role in disease transmission remains unclear. While they appear to be relatively resistant to natural CWD infection and disease, they could potentially contribute towards the maintenance and spread of CWD in Great Britain’s cervid population (Soto et al., 2025).
To reduce the risk of CWD introduction, Great Britain suspended the import of live cervids and high-risk cervid products in June 2023, including urine hunting lures, from all countries where CWD has been reported. Fresh cervid meat, excluding offal and spinal cord, can only be imported into Great Britain from CWD-affected countries if it has tested negative for CWD using an approved diagnostic method, such as immunohistochemistry, and originates from an area where CWD has not been reported or officially suspected in the last 3 years (Defra and APHA, 2026).
The current risk of CWD prions being introduced into Great Britain’s wild pig or cervid population ranges from very low (event is very rare but cannot be excluded) to negligible (event is so rare it does not merit consideration). This is based on the risk of incursion tool, developed by Roberts et al., (2011). It is also supported by a recent Defra and APHA (2025) risk assessment. While this assessment identified a few theoretical entry pathways, such as contaminated equipment, that could not be fully assessed due to limited data, there is no definitive evidence that they have ever resulted in the introduction of CWD into a new area.
Detection of CWD prions in wild pigs in the USA is unlikely to affect Great Britain’s CWD risk level, as the USA is not approved to export live wild pigs to Great Britain (Defra, 2025). Import of infected wild pig meat or wild pig by-products from the USA could theoretically introduce CWD prions into Great Britain, but the risk of this is also very low. To date, CWD prions have only been reported in lymph node and brain tissue samples in wild pigs, at levels too low to cause disease in mouse models
Department for Environment, Food and Rural Affairs
(Soto et al., 2025). However, their presence in other tissues cannot be excluded. The USA is approved to export wild pig meat and certain wild pig by-products to Great Britain, excluding offal, minced meat and germplasm (Defra, 2025), but there appears to be limited trade in these commodities.
It is difficult to quantify the exact amount of wild pig meat exported to Great Britain, as available trade data does not always distinguish between meat of wild and domestic pigs. However, based on HMRC data, the last known export of non- domestic pig meat from the USA to Great Britain was in 2013 (4,881 kg).
Conclusion
CWD has continued to spread among captive and free-ranging cervids in North America since it was first detected in the 1960s. The finding of CWD prions in wild pigs in the USA suggests they could contribute towards transmission of the disease, influencing its epidemiology, geographic distribution and interspecies spread. However, further research is needed to confirm this. CWD has never been reported in Great Britain and the current risk of CWD prions being introduced into Great Britain’s wild pig or cervid population ranges from very low to negligible.
Readers are reminded to be vigilant for signs of CWD. Information on how to spot the disease can be found here. Suspected cases must be reported immediately to the Defra Rural Services Helpline on 03000 200 301. In Wales, call 0300 303 8268. In Scotland, contact your local Field Services Office. Failure to do so is an offence. We will continue to monitor the situation.
Authors • Lawrence Finn • Dr. Lauren Perrin • John Spiropoulos • Dr. Helen RobertsDepartment for Environment, Food and Rural Affairs
References
snip…see;
Confucius Ponders, what about Wild Pigs (Sus scrofa) and CWD TSE Prion, and the Environment, what if?
Shedding, retention and spreading of chronic wasting disease prions in the environment
Project Number 2R01AI132695-06A1 Former Number 2R01AI132695-06 Contact PI/Project Leader MORALES, RODRIGO
Abstract Text
ABSTRACT
Chronic Wasting Disease (CWD) is a prion disease affecting natural and captive cervid populations. This disease is progressively spreading across the United States and new foci of infectivity are constantly being reported. Despite decades of research, there are still several unanswered questions concerning CWD.
Compelling evidence suggest that CWD prions enter the environment through carcasses from diseased animals or by the progressive accumulation of prions shed in excreta. Unfortunately, the role that plants, parasites, predators, and scavengers play in CWD spreading has been poorly studied. During the past funding cycle, our group made important technical and conceptual contributions in this field.
Data from our group and others (in collaboration) demonstrate that plants can bind prions into their surfaces as well as transport them from soils to leaves. This is relevant, considering that prions are shown to progressively accumulate in soils and strongly suggests plants as potential vectors for CWD transmission. Unfortunately, the previously mentioned evidence has been collected using proof-of-concept conditions, including the exposure of high titers of rodent (laboratory generated) adapted prions, and grass plants only.
We have generated preliminary data showing that carrots grown in CWD infected soil carry prions in their roots and leaves as evaluated by bioassays. In contrast, tomato plants do not share these features. The significance of these findings cannot be ignored considering the interaction of CWD prions with a human and animal edible vegetable. Considering the use of carrots roots and leaves in human and animal nutrition, and the still unknown zoonotic potential of CWD, future research involving edible plants is urgently needed.
Another relevant (published) finding from our laboratory involves the high CWD infectivity titers found in nasal bots, a common cervid parasite that develops in the nasal cavity (a hotspot of prion infectivity). These parasites are found in large quantities in CWD pre- clinical and clinical deer, and may importantly contribute to environmental CWD transmission. Our research also identified CWD prions in naturally exposed flies, ticks, and dermestid beetles. However, the prion infectivity titers in these parasites have not been evaluated.
Finally, animals other than cervids, including hunters and scavengers, are expected to be exposed to CWD prions. Interestingly, we identified CWD prions and de novo generated porcine prions in tissues from wild pigs living in areas with variable CWD epidemiology. We plan to further investigate all these events and their relevance in natural prion transmission using a complementary set of techniques, including in vitro and in vivo systems. Emphasis will be made in analyzing the strain properties and zoonotic potentials of the prion agents under investigation. For this purpose, we gathered a unique group of collaborators able to supply us with the samples and expertise required to execute this project. Outcomes from this research are expected to deliver new insights on this animal prionopathy and provide regulatory agencies with useful information to control its continuous spread.
Public Health Relevance Statement
PROJECT NARRATIVE Despite decades of research, several questions remain unanswered for the Chronic Wasting Disease (CWD) epidemic affecting several deer species in the United States. Continuing with our previous R01 project, we will explore novel factors mediating the spread of CWD prions, including different plant types, invertebrate parasites (e.g., ticks, nasal bots) and scavengers (wild boars). These potential disease vectors will be studied for their ability to transmit disease within and across species, including humans.
https://reporter.nih.gov/search/VYlhnadNtUiur19eYeRPog/project-details/11227445#description
Infectious prions in brains and muscles of domestic pigs experimentally challenged with the BSE, scrapie, and CWD agents
Authors: Francisca Bravo-Risi, Fraser Brydon, Angela Chong, Kane Spicker, Justin J. Greenlee https://orcid.org/0000-0003-2202-3054, Glenn Telling, Claudio Soto https://orcid.org/0000-0002-3412-0524, Sandra Pritzkow, Marcelo A. Barria, Rodrigo Morales
ABSTRACT
Experimental studies suggest that animal species not previously described as naturally infected by prions are susceptible to prion diseases affecting sheep, cattle, and deer. These interspecies transmissions may generate prions with unknown host ranges. Pigs are susceptible to prions from different origins, including deer chronic wasting disease (CWD), sheep scrapie, and bovine spongiform encephalopathy (BSE). Here, we studied prions in brains and muscles from pigs previously infected with these different prion sources. Specifically, we measured the total prion protein (PrP) and PK-resistant PrP by western blot. Seeding activity in these tissues was evaluated using the protein misfolding cyclic amplification (PMCA) technique. We found that BSE-infected pigs contained substantially more seeding competent prions compared with those infected with CWD and scrapie. Moreover, the zoonotic potential of porcine-BSE prions seems to be relevant, as both brains and muscles from BSE-infected pigs induced the misfolding of the human prion protein in vitro. This study helps to understand the potential fate of naturally existing prion strains in a relevant host and calls for caution considering the co-existence between feral swine and other prion-susceptible animal species.
IMPORTANCE
Prions (PrPSc) are proteinaceous, infectious pathogens responsible for prion diseases. Some livestock are highly susceptible to prion diseases. These include cattle (bovine spongiform encephalopathy, BSE), sheep and goat (scrapie), and cervids (chronic wasting disease, CWD). Unfortunately, BSE has been reported to be naturally transmitted to humans and other animal species. Domestic pigs, a relevant livestock animal, have not been reported to be naturally affected by prions; however, they are susceptible to the experimental exposure to BSE, scrapie, and CWD prions. Given the widespread consumption of porcine food products by humans, we aimed to evaluate the levels of pig-derived BSE, scrapie, and CWD prions from experimentally challenged domestic pigs in brain and meat cuts (leg, cheek meat, skirt meat, and tenderloin). We detected pig-adapted prions in the brains and some muscles of these animals. Additionally, we evaluated the in vitro compatibility between pig prions and the human prion protein (as a surrogate of zoonosis). Our results show that only pig-derived BSE prions were able to induce the misfolding of the cellular human prion protein. This data highlights the consequences of prion spillovers to other animal species and their potential availability to humans.
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In summary, our data shows the dynamic of animal prions when exposed to infectious pigs, as well as their distributions and zoonotic potentials. The data presented here may be relevant to understanding the fate of naturally existing prions in a sympatric animal species relevant for human consumption. This acquires importance considering a recent report describing the interaction between CWD and wild pigs in natural settings.
https://journals.asm.org/doi/10.1128/mbio.01800-25
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
Paulina Soto, Francisca Bravo-Risi, Rebeca Benavente, Tucker H. Stimming, Michael J. Bodenchuk, Patrick Whitley, Clint Turnage, Terry R. Spraker, Justin Greenlee, Glenn Telling, Jennifer Malmberg, Thomas Gidlewski, Tracy Nichols, Vienna R. Brown, and Rodrigo Morales Author affiliation: The University of Texas Health Science Center at Houston, Texas, USA (P. Soto, F. Bravo-Risi, R. Benavente, T.H. Stimming, R. Morales); Centro Integrativo de Biologia y Quimica Aplicada, Universidad Bernardo O’Higgins, Santiago, Chile (P. Soto, F. Bravo-Risi, R. Morales); US Department of Agriculture, Fort Collins, Colorado, USA (M.J. Bodenchuk, P. Whitley, C. Turnage, J. Malmberg, T. Gidlewski, T. Nichols, V.R. Brown); Colorado State University, Fort Collins, Colorado, USA (T.R. Spraker, G. Telling); US Department of Agriculture, Ames, Iowa, USA (J. Greenlee)
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.
Chronic wasting disease (CWD) is a prion disease of particular concern because of its uncontrolled contagious spread among various cervid species in North America
its recent discovery in Nordic countries (1), and its increasingly uncertain zoonotic potential (2). CWD is the only animal prion disease affecting captive as well as wild animals. Persistent shedding of prions by CWD-affected animals and resulting environmental contamination is considered a major route of transmission contributing to spread of the disease. Carcasses of CWD-affected animals represent relevant sources of prion infectivity to multiple animal species that can develop disease or act as vectors to spread infection to new locations.
Free-ranging deer are sympatric with multiple animal species, including some that act as predators, scavengers, or both. Experimental transmissions to study the potential for interspecies CWD transmissions have been attempted in raccoons, ferrets, cattle, sheep, and North American rodents (3–7). Potential interspecies CWD transmission has also been addressed using transgenic (Tg) mice expressing prion proteins (PrP) from relevant animal species (8). Although no reports of natural interspecies CWD transmissions have been documented, experimental studies strongly suggest the possibility for interspecies transmission in nature exists (3–7). Inoculation and serial passage studies reveal the potential of CWD prions to adapt to noncervid species, resulting in emergence of novel prion strains with unpredicted features (9–11).
Wild pigs (Sus scrofa), also called feral swine, are an invasive population comprising domestic swine, Eurasian wild boar, and hybrids of the 2 species (12). Wild pig populations have become established in the United States (Appendix Figure 1, panel A), enabled by their high rates of fecundity; omnivorous and opportunistic diet; and widespread, often human-mediated movement (13). Wild pigs scavenge carcasses on the landscape and have an intimate relationship with the soil because of their routine rooting and wallowing behaviors (14). CWD prions have been experimentally transmitted to domestic pigs by intracerebral and oral exposure routes (15), which is relevant because wild pigs coexist with cervids in CWD endemic areas and reportedly prey on fawns and scavenge deer carcasses. Considering the species overlap in many parts of the United States (Appendix Figure 1, panel B), we studied potential interactions between wild pigs and CWD prions.
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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/31/1/24-0401_article
Title: Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains…
https://www.ars.usda.gov/research/publications/publication/?seqNo115=337105
CWD TSE Prion, Pigs, Transmission, Livestock, Humans, what if?
CONFIDENTIAL
EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY
While this clearly is a cause for concern we should not jump to the conclusion that this means that pigs will necessarily be infected by bone and meat meal fed by the oral route as is the case with cattle…
http://web.archive.org/web/20031026000118/www.bseinquiry.gov.uk/files/yb/1990/08/23004001.pdf
we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action…
http://web.archive.org/web/20030822031154/www.bseinquiry.gov.uk/files/yb/1990/09/10007001.pdf
May I, at the outset, reiterate that we should avoid dissemination of papers relating to this experimental finding to prevent premature release of the information…
http://web.archive.org/web/20030822052332/www.bseinquiry.gov.uk/files/yb/1990/09/11005001.pdf
3. It is particularly important that this information is not passed outside the Department, until Ministers have decided how they wish it to be handled…
http://web.archive.org/web/20030822052438/www.bseinquiry.gov.uk/files/yb/1990/09/12002001.pdf
But it would be easier for us if pharmaceuticals/devices are not directly mentioned at all…
http://web.archive.org/web/20030518170213/www.bseinquiry.gov.uk/files/yb/1990/09/13004001.pdf
Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom...
http://web.archive.org/web/20030822054419/www.bseinquiry.gov.uk/files/yb/1990/09/21009001.pdf
It was not until . . . August 1990, that the result from the pig persuaded both SEAC and us to change our view and to take out of pig rations any residual infectivity that might have arisen from the SBOs.
http://web.archive.org/web/20071014143511/http://www.bseinquiry.gov.uk/files/tr/tab69.pdf
4.303 The minutes of the meeting record that:
It was very difficult to draw conclusions from one experimental result for what may happen in the field. However it would be prudent to exclude specified bovine offals from the pig diet. Although any relationship between BSE and the finding of a spongiform encephalopathy in cats had yet to be demonstrated, the fact that this had occurred suggested that a cautious view should be taken of those species which might be susceptible. The 'specified offals' of bovines should therefore be excluded from the feed of all species. 17
http://web.archive.org/web/20031026084516/http://www.bseinquiry.gov.uk/files/yb/1990/09/07001001.pdf
IN CONFIENCE
EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY
1. CMO should be aware that a pig inoculated experimentally (ic, iv, and ip) with BSE brain suspension has after 15 months developed an illness, now confirmed as a spongiform encephalopathy. This is the first ever description of such a disease in a pig, although it seems there ar no previous attempts at experimental inoculation with animal material. The Southwood group had thought igs would not be susceptible. Most pigs are slaughtered when a few weeks old but there have been no reports of relevant neurological illness in breeding sows or other elderly pigs. ...see full text ;
http://web.archive.org/web/20040302031004/www.bseinquiry.gov.uk/files/yb/1990/08/23001001.pdf
IN CONFIDENCE
So it is plausible pigs could be preclinically affected with BSE but since so few are allowed to reach adulthood this has not been recognised through clinical disease…
http://web.archive.org/web/20040904150118/www.bseinquiry.gov.uk/files/yb/1990/08/23002001.pdf
we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action…
http://web.archive.org/web/20030822031154/www.bseinquiry.gov.uk/files/yb/1990/09/10007001.pdf
May I, at the outset, reiterate that we should avoid dissemination of papers relating to this experimental finding to prevent premature release of the information…
http://web.archive.org/web/20030822052332/www.bseinquiry.gov.uk/files/yb/1990/09/11005001.pdf
3. It is particularly important that this information is not passed outside the Department, until Ministers have decided how they wish it to be handled…
http://web.archive.org/web/20030822052438/www.bseinquiry.gov.uk/files/yb/1990/09/12002001.pdf
But it would be easier for us if pharmaceuticals/devices are not directly mentioned at all…
http://web.archive.org/web/20030518170213/www.bseinquiry.gov.uk/files/yb/1990/09/13004001.pdf
Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom.....
http://web.archive.org/web/20030822054419/www.bseinquiry.gov.uk/files/yb/1990/09/21009001.pdf
BSE TO PIGS NEWS RELEASE
http://web.archive.org/web/20030822162313/www.bseinquiry.gov.uk/files/yb/1990/09/24001001.pdf
CONFIDENTIAL
BSE: PRESS PRESENTATION
http://web.archive.org/web/20030822160958/www.bseinquiry.gov.uk/files/yb/1990/09/20003001.pdf
http://web.archive.org/web/20040623191707/www.bseinquiry.gov.uk/files/yb/1990/09/24013001.pdf
http://web.archive.org/web/20030820195733/http://www.bseinquiry.gov.uk/files/yb/1990/09/20010001.pdf
http://web.archive.org/web/20030820195733/http://www.bseinquiry.gov.uk/files/yb/1990/09/25013001.pdf
http://web.archive.org/web/20030820195733/http://www.bseinquiry.gov.uk/files/yb/1990/09/25015001.pdf
INDUSTRY RESPONSE TYPICAL
http://web.archive.org/web/20030822055917/www.bseinquiry.gov.uk/files/yb/1990/09/25007001.pdf
DEFENSIVE BRIEFING
http://web.archive.org/web/20030820195733/http://www.bseinquiry.gov.uk/files/yb/1990/09/25016001.pdf
CONFIDENTIAL
pigs & pharmaceuticals
http://web.archive.org/web/20010305223234/www.bseinquiry.gov.uk/files/yb/1990/09/10007001.pdf
http://web.archive.org/web/20010305223234/www.bseinquiry.gov.uk/files/yb/1990/08/23002001.pdf
http://web.archive.org/web/20010305223234/www.bseinquiry.gov.uk/files/yb/1990/08/23004001.pdf
http://web.archive.org/web/20010305223234/www.bseinquiry.gov.uk/files/yb/1990/08/29003001.pdf
COMMERCIAL IN CONFIDENCE COMMITTEE ON SAFETY OF MEDICINE NOT FOR PUBLICATION BOVINE SPONGIFORM ENCEPHALOPATHY WORKING GROUP
There are only two products using porcine brain and these use corticotrophin BP, made from porcine pituitary, source from outside the UK...
http://web.archive.org/web/20040622220349/www.bseinquiry.gov.uk/files/yb/1990/10/31003001.pdf
snip...
7 OF 10 LITTLE PIGGIES WENT ON TO DEVELOP BSE;
1: J Comp Pathol. 2000 Feb-Apr; 122(2-3): 131-43. Related Articles,
The neuropathology of experimental bovine spongiform encephalopathy in the pig.
Ryder SJ, Hawkins SA, Dawson M, Wells GA.
Veterinary Laboratories Agency Weybridge, Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, UK.
In an experimental study of the transmissibility of BSE to the pig, seven of 10 pigs, infected at 1-2weeks of age by multiple-route parenteral inoculation with a homogenate of bovine brain from natural BSE cases developed lesions typical of spongiform encephalopathy. The lesions consisted principally of severe neuropil vacuolation affecting most areas of the brain, but mainly the forebrain. In addition, some vacuolar change was identified in the rostral colliculi and hypothalamic areas of normal control pigs. PrP accumulations were detected immunocytochemically in the brains of BSE-infected animals. PrP accumulation was sparse in many areas and its density was not obviously related to the degree of vacuolation. The patterns of PrP immunolabelling in control pigs differed strikingly from those in the infected animals.
PMID: 10684682 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?holding=npg&cmd=Retrieve&db=PubMed&list_uids=10684682&dopt=Abstract
The current feed ban in the U.S. is based exclusively on keeping tissues from TSE infected cattle from entering animal feeds. These results indicating the susceptibility of pigs to CWD, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=353091
https://www.ars.usda.gov/research/project/?accnNo=432011&fy=2017
https://www.ars.usda.gov/research/publications/publication/?seqNo115=337105
https://www.ars.usda.gov/research/publications/publication/?seqNo115=326166
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed
PUBLIC SUBMISSION
Comment from Terry Singeltary Sr.
Posted by the Food and Drug Administration on May 17, 2016 Comment
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission
https://www.regulations.gov/comment/FDA-2003-D-0432-0011
https://www.regulations.gov/docket/FDA-2003-D-0432
Infectious prions in brains and muscles of domestic pigs experimentally challenged with the BSE, scrapie, and CWD agents
https://prpsc.proboards.com/thread/179/scrapie-prions-brains-muscles-pigs
https://transmissiblespongiformencephalopathy.blogspot.com/2025/08/infectious-prions-in-brains-and-muscles.html
With great urgency, I kindly wish to submit my concerns with FY 2025 Plant Pest and Disease Management and Disaster Prevention Program (PPDMDPP) and National Clean Plant Network (NCPN) program, with relations to some plants and such that have been omitted from said program, and why with great urgency they should/must be addressed, concerning Transmissible Spongiform Encephalopathy TSE Prion disease, Chronic Wasting Disease, Environmental Contamination, and updated of the TSE Prion via plants, namely the ones i am concerned with, in which have been omitted.
Countries have already started to raise concern with Hay and Straw from locations where Chronic Wasting Disease CWD TSE Prion has been detected, and have ask that said plants must be accompanied by a certificate from a public veterinarian that the product has been harvested in states or provinces where Chronic Wasting Disease has not been detected on deer (see reference materials below).
But, with CWD TSE Prion spreading without control across North America, Korea, Norway, Finland, and Sweden, the fact that plant uptake of the CWD TSE Prion, and transmission there from, has been proven in testing, along with the fact that spillover of CWD TSE Prion to other species, by oral routes, i.e. Humans, Monkeys, Cattle, Sheep, Pigs, rodents, raccoons, I believe that it is extremely important to add TSE Prion Disease to the FY 2025 Plant Pest and Disease Management and Disaster Prevention Program (PPDMDPP) and National Clean Plant Network (NCPN) program, without hesitation....
Thank You Kindly, Terry S. Singeltary Sr., Bacliff, Texas
https://scrapie-usa.blogspot.com/2025/12/scrapie-tse-prion-usa-rapid-response.html
https://prpsc.proboards.com/thread/186/scrapie-prion-response-urgent-updates
https://transmissiblespongiformencephalopathy.blogspot.com/2025/12/2026-usda-explanatory-notes-aphis-cwd.html
Location: Virus and Prion Research
2025 Annual Report
USDA EXPLANATORY NOTES ANIMAL AND PLANT HEALTH INSPECTION SERVICE 2025-2014 CHRONIC WASTING DISEASE CWD TSE CERVID
https://chronic-wasting-disease.blogspot.com/2025/09/usda-explanatory-notes-animal-and-plant.html
TUESDAY, SEPTEMBER 30, 2025
USDA National Scrapie Program History and Bovine Spongiform Encephalopathy BSE TSE Update 2025
https://bovineprp.blogspot.com/2025/09/usda-national-scrapie-program-history.html
TUESDAY, SEPTEMBER 30, 2025
USDA National Scrapie Program History and Bovine Spongiform Encephalopathy BSE TSE Update 2025
https://scrapie-usa.blogspot.com/2025/09/usda-national-scrapie-program-history.html
While no one was watching: Tenuous status of CDC prion unit, risk of CWD to people worry scientists
https://chronic-wasting-disease.blogspot.com/2025/11/while-no-one-was-watching-tenuous.html
Neuropsychiatric symptoms in sporadic Creutzfeldt-Jakob disease, a review
https://creutzfeldt-jakob-disease.blogspot.com/2026/01/neuropsychiatric-symptoms-in-sporadic.html
https://prpsc.proboards.com/thread/191/neuropsychiatric-symptoms-sporadic-cjd-review
