CDC Assesses Potential Human Exposure to Prion Diseases Travel Warning
Public release date: 23-May-2011
CDC assesses potential human exposure to prion diseases Study results reported in the Journal of the American Dietetic Association Philadelphia, PA, May 23, 2011 – Researchers from the Centers for Disease Control and Prevention (CDC) have examined the potential for human exposure to prion diseases, looking at hunting, venison consumption, and travel to areas in which prion diseases have been reported in animals. Three prion diseases in particular – bovine spongiform encephalopathy (BSE or “Mad Cow Disease”), variant Creutzfeldt-Jakob disease (vCJD), and chronic wasting disease (CWD) – were specified in the investigation. The results of this investigation are published in the June issue of the Journal of the American Dietetic Association.
“While prion diseases are rare, they are generally fatal for anyone who becomes infected. More than anything else, the results of this study support the need for continued surveillance of prion diseases,” commented lead investigator Joseph Y. Abrams, MPH, National Center for Emerging and Zoonotic Infectious Diseases, CDC, Atlanta.”But it’s also important that people know the facts about these diseases, especially since this study shows that a good number of people have participated in activities that may expose them to infection-causing agents.”
Although rare, human prion diseases such as CJD may be related to BSE. Prion (proteinaceous infectious particles) diseases are a group of rare brain diseases that affect humans and animals. When a person gets a prion disease, brain function is impaired. This causes memory and personality changes, dementia, and problems with movement. All of these worsen over time. These diseases are invariably fatal. Since these diseases may take years to manifest, knowing the extent of human exposure to possible prion diseases could become important in the event of an outbreak.
CDC investigators evaluated the results of the 2006-2007 population survey conducted by the Foodborne Diseases Active Surveillance Network (FoodNet). This survey collects information on food consumption practices, health outcomes, and demographic characteristics of residents of the participating Emerging Infections Program sites. The survey was conducted in Connecticut, Georgia, Maryland, Minnesota, New Mexico, Oregon, and Tennessee, as well as five counties in the San Francisco Bay area, seven counties in the Greater Denver area, and 34 counties in western and northeastern New York.
Survey participants were asked about behaviors that could be associated with exposure to the agents causing BSE and CWD, including travel to the nine countries considered to be BSE-endemic (United Kingdom, Republic of Ireland, France, Portugal, Switzerland, Italy, the Netherlands, Germany, Spain) and the cumulative length of stay in each of those countries. Respondents were asked if they ever had hunted for deer or elk, and if that hunting had taken place in areas considered to be CWD-endemic (northeastern Colorado, southeastern Wyoming or southwestern Nebraska). They were also asked if they had ever consumed venison, the frequency of consumption, and whether the meat came from the wild.
The proportion of survey respondents who reported travel to at least one of the nine BSE endemic countries since 1980 was 29.5%. Travel to the United Kingdom was reported by 19.4% of respondents, higher than to any other BSE-endemic country. Among those who traveled, the median duration of travel to the United Kingdom (14 days) was longer than that of any other BSE-endemic country. Travelers to the UK were more likely to have spent at least 30 days in the country (24.9%) compared to travelers to any other BSE endemic country. The prevalence and extent of travel to the UK indicate that health concerns in the UK may also become issues for US residents.
The proportion of survey respondents reporting having hunted for deer or elk was 18.5% and 1.2% reported having hunted for deer or elk in CWD-endemic areas. Venison consumption was reported by 67.4% of FoodNet respondents, and 88.6% of those reporting venison consumption had obtained all of their meat from the wild. These findings reinforce the importance of CWD surveillance and control programs for wild deer and elk to reduce human exposure to the CWD agent. Hunters in CWD-endemic areas are advised to take simple precautions such as: avoiding consuming meat from sickly deer or elk, avoiding consuming brain or spinal cord tissues, minimizing the handling of brain and spinal cord tissues, and wearing gloves when field-dressing carcasses.
According to Abrams, “The 2006-2007 FoodNet population survey provides useful information should foodborne prion infection become an increasing public health concern in the future. The data presented describe the prevalence of important behaviors and their associations with demographic characteristics. Surveillance of BSE, CWD, and human prion diseases are critical aspects of addressing the burden of these diseases in animal populations and how that may relate to human health.”
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The article is “Travel history, hunting, and venison consumption related to prion disease exposure, 2006-2007 FoodNet population survey” by Joseph Y. Abrams, MPH; Ryan A. Maddox, MPH; Alexis R Harvey, MPH; Lawrence B. Schonberger, MD; and Ermias D. Belay, MD. It appears in the Journal of the American Dietetic Association, Volume 111, Issue 6 (June 2011) published by Elsevier.
Thursday, May 26, 2011
Travel History, Hunting, and Venison Consumption Related to Prion Disease Exposure, 2006-2007 FoodNet Population Survey
Journal of the American Dietetic Association Volume 111, Issue 6 , Pages 858-863, June 2011.
Travel History, Hunting, and Venison Consumption Related to Prion Disease Exposure, 2006-2007 FoodNet Population Survey
Joseph Y. Abrams, MPH, Ryan A. Maddox, MPH , Alexis R. Harvey, MPH , Lawrence B. Schonberger, MD , Ermias D. Belay, MD
Accepted 15 November 2010. Abstract Full Text PDF References .
Abstract
The transmission of bovine spongiform encephalopathy (BSE) to human beings and the spread of chronic wasting disease (CWD) among cervids have prompted concerns about zoonotic transmission of prion diseases. Travel to the United Kingdom and other European countries, hunting for deer or elk, and venison consumption could result in the exposure of US residents to the agents that cause BSE and CWD. The Foodborne Diseases Active Surveillance Network 2006-2007 population survey was used to assess the prevalence of these behaviors among residents of 10 catchment areas across the United States. Of 17,372 survey respondents, 19.4% reported travel to the United Kingdom since 1980, and 29.5% reported travel to any of the nine European countries considered to be BSE-endemic since 1980. The proportion of respondents who had ever hunted deer or elk was 18.5%, and 1.2% had hunted deer or elk in a CWD–endemic area. More than two thirds (67.4%) reported having ever eaten deer or elk meat. Respondents who traveled spent more time in the United Kingdom (median 14 days) than in any other BSE-endemic country. Of the 11,635 respondents who had consumed venison, 59.8% ate venison at most one to two times during their year of highest consumption, and 88.6% had obtained all of their meat from the wild. The survey results were useful in determining the prevalence and frequency of behaviors that could be important factors for foodborne prion transmission.
PLUS, THE CDC DID NOT PUT THIS WARNING OUT FOR THE WELL BEING OF THE DEER AND ELK ;
Thursday, May 26, 2011
Travel History, Hunting, and Venison Consumption Related to Prion Disease Exposure, 2006-2007 FoodNet Population Survey
Journal of the American Dietetic Association Volume 111, Issue 6 , Pages 858-863, June 2011.
NOR IS THE FDA recalling this CWD positive elk meat for the well being of the dead elk ;
Wednesday, March 18, 2009
Noah's Ark Holding, LLC, Dawson, MN RECALL Elk products contain meat derived from an elk confirmed to have CWD NV, CA, TX, CO, NY, UT, FL, OK RECALLS AND FIELD CORRECTIONS: FOODS CLASS II
Thursday, May 26, 2011
Travel History, Hunting, and Venison Consumption Related to Prion Disease Exposure, 2006-2007
FoodNet Population Survey Journal of the American Dietetic Association Volume 111, Issue 6 , Pages 858-863, June 2011.
Travel History, Hunting, and Venison Consumption Related to Prion Disease Exposure, 2006-2007 FoodNet Population Survey
Joseph Y. Abrams, MPH, Ryan A. Maddox, MPH , Alexis R. Harvey, MPH , Lawrence B. Schonberger, MD , Ermias D. Belay, MD
Accepted 15 November 2010. Abstract Full Text PDF References .
Abstract
The transmission of bovine spongiform encephalopathy (BSE) to human beings and the spread of chronic wasting disease (CWD) among cervids have prompted concerns about zoonotic transmission of prion diseases. Travel to the United Kingdom and other European countries, hunting for deer or elk, and venison consumption could result in the exposure of US residents to the agents that cause BSE and CWD. The Foodborne Diseases Active Surveillance Network 2006-2007 population survey was used to assess the prevalence of these behaviors among residents of 10 catchment areas across the United States. Of 17,372 survey respondents, 19.4% reported travel to the United Kingdom since 1980, and 29.5% reported travel to any of the nine European countries considered to be BSE-endemic since 1980. The proportion of respondents who had ever hunted deer or elk was 18.5%, and 1.2% had hunted deer or elk in a CWD–endemic area. More than two thirds (67.4%) reported having ever eaten deer or elk meat. Respondents who traveled spent more time in the United Kingdom (median 14 days) than in any other BSE-endemic country. Of the 11,635 respondents who had consumed venison, 59.8% ate venison at most one to two times during their year of highest consumption, and 88.6% had obtained all of their meat from the wild. The survey results were useful in determining the prevalence and frequency of behaviors that could be important factors for foodborne prion transmission.
"These findings indicate that a high percentage of the United States population engages in hunting and/or venison consumption. If CWD continues to spread to more areas across the country, a substantial number of people could potentially be exposed to the infectious agent."
Potential Venison Exposure Among FoodNet Population Survey Respondents, 2006-2007
Ryan A. Maddox1*, Joseph Y. Abrams1, Robert C. Holman1, Lawrence B. Schonberger1, Ermias D. Belay1 Division of Viral and Rickettsial Diseases, National Center for Zoonotic, Vector-Borne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, GA *Corresponding author e-mail: rmaddox@cdc.gov
The foodborne transmission of bovine spongiform encephalopathy to humans, resulting in variant Creutzfeldt-Jakob disease, indicates that humans can be susceptible to animal prion diseases. However, it is not known whether foodborne exposure to the agent causing chronic wasting disease (CWD) in cervids can cause human disease. The United States Foodborne Diseases Active Surveillance Network (FoodNet) conducts surveillance for foodborne diseases through an extensive survey administered to respondents in selected states. To describe the frequency of deer and elk hunting and venison consumption, five questions were included in the 2006-2007 FoodNet survey. This survey included 17,372 respondents in ten states: California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee. Of these respondents, 3,220 (18.5%) reported ever hunting deer or elk, with 217 (1.3%) reporting hunting in a CWD-endemic area (northeastern Colorado, southeastern Wyoming, and southwestern Nebraska). Of the 217 CWD-endemic area hunters, 74 (34.1%) were residents of Colorado. Respondents reporting hunting were significantly more likely to be male than female (prevalence ratio: 3.3, 95% confidence interval: 3.1-3.6) and, in general, older respondents were significantly more likely to report hunting than younger respondents. Venison consumption was reported by more than half (67.4%) of the study population, and most venison consumers (94.1%) reported that at least half of their venison came from the wild. However, more than half (59.1%) of the consumers reported eating venison only one to five times in their life or only once or twice a year. These findings indicate that a high percentage of the United States population engages in hunting and/or venison consumption. If CWD continues to spread to more areas across the country, a substantial number of people could potentially be exposed to the infectious agent.
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases). Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
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***thus questioning the origin of human sporadic cases***
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***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
==============
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online
Taylor & Francis
Prion 2016 Animal Prion Disease Workshop Abstracts
WS-01: Prion diseases in animals and zoonotic potential
Juan Maria Torres a, Olivier Andreoletti b, J uan-Carlos Espinosa a. Vincent Beringue c. Patricia Aguilar a,
Natalia Fernandez-Borges a. and Alba Marin-Moreno a
"Centro de Investigacion en Sanidad Animal ( CISA-INIA ). Valdeolmos, Madrid. Spain; b UMR INRA -ENVT 1225 Interactions Holes Agents Pathogenes. ENVT. Toulouse. France: "UR892. Virologie lmmunologie MolécuIaires, Jouy-en-Josas. France
Dietary exposure to bovine spongiform encephalopathy (BSE) contaminated bovine tissues is considered as the origin of variant Creutzfeldt Jakob (vCJD) disease in human. To date, BSE agent is the only recognized zoonotic prion. Despite the variety of Transmissible Spongiform Encephalopathy (TSE) agents that have been circulating for centuries in farmed ruminants there is no apparent epidemiological link between exposure to ruminant products and the occurrence of other form of TSE in human like sporadic Creutzfeldt Jakob Disease (sCJD). However, the zoonotic potential of the diversity of circulating TSE agents has never been systematically assessed. The major issue in experimental assessment of TSEs zoonotic potential lies in the modeling of the ‘species barrier‘, the biological phenomenon that limits TSE agents’ propagation from a species to another. In the last decade, mice genetically engineered to express normal forms of the human prion protein has proved essential in studying human prions pathogenesis and modeling the capacity of TSEs to cross the human species barrier.
To assess the zoonotic potential of prions circulating in farmed ruminants, we study their transmission ability in transgenic mice expressing human PrPC (HuPrP-Tg). Two lines of mice expressing different forms of the human PrPC (129Met or 129Val) are used to determine the role of the Met129Val dimorphism in susceptibility/resistance to the different agents.
These transmission experiments confirm the ability of BSE prions to propagate in 129M- HuPrP-Tg mice and demonstrate that Met129 homozygotes may be susceptible to BSE in sheep or goat to a greater degree than the BSE agent in cattle and that these agents can convey molecular properties and neuropathological indistinguishable from vCJD. However homozygous 129V mice are resistant to all tested BSE derived prions independently of the originating species suggesting a higher transmission barrier for 129V-PrP variant.
Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly 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.
snip...
R. BRADLEY
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
WEDNESDAY, OCTOBER 4, 2017
*** EFSA Scientific Report on the Assessment of the Geographical BSE-Risk (GBR) of the United States of America (USA) a review 2017 ***
TUESDAY, AUGUST 8, 2017
Concurrence With OIE Risk Designations for Bovine Spongiform Encephalopathy [Docket No. APHIS-2016-0092]
I urge everyone to watch this video closely...terry
*** you can see video here and interview with Jeff's Mom, and scientist telling you to test everything and potential risk factors for humans ***
P.97: Scrapie transmits to white-tailed deer by the oral route and has a molecular profile similar to chronic wasting disease and distinct from the scrapie inoculum
Justin Greenlee1, S JO Moore1, Jodi Smith1, M Heather WestGreenlee2 and Robert Kunkle1
1National Animal Disease Center; Ames, IA USA
2Iowa State University; Ames, IA USA
The purpose of this work was to determine susceptibility of white-tailed deer (WTD) to the agent of sheep scrapie and to compare the resultant PrPSc to that of the original inoculum and chronic wasting disease (CWD). We inoculated WTD by a natural route of exposure (concurrent oral and intranasal (IN); n = 5) with a US scrapie isolate. All scrapie-inoculated deer had evidence of PrPSc accumulation. PrPSc was detected in lymphoid tissues at preclinical time points, and deer necropsied after 28 months post-inoculation had clinical signs, spongiform encephalopathy, and widespread distribution of PrPSc in neural and lymphoid tissues. Western blotting (WB) revealed PrPSc with 2 distinct molecular profiles. WB on cerebral cortex had a profile similar to the original scrapie inoculum, whereas WB of brainstem, cerebellum, or lymph nodes revealed PrPSc with a higher profile resembling CWD. Homogenates with the 2 distinct profiles from WTD with clinical scrapie were further passaged to mice expressing cervid prion protein and intranasally to sheep and WTD. In cervidized mice, the 2 inocula have distinct incubation times. Sheep inoculated intranasally with WTD derived scrapie developed disease, but only after inoculation with the inoculum that had a scrapie-like profile. The WTD study is ongoing, but deer in both inoculation groups are positive for PrPSc by rectal mucosal biopsy.
***In summary, this work demonstrates that WTD are susceptible to the agent of scrapie, 2 distinct molecular profiles of PrPSc are present in the tissues of affected deer, and inoculum of either profile readily passes to deer.
*** After a natural route of exposure, 100% of WTD were susceptible to scrapie.
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA
White-tailed deer are susceptible to the agent of sheep scrapie by intracerebral inoculation
snip...
It is unlikely that CWD will be eradicated from free-ranging cervids, and the disease is likely to continue to spread geographically [10]. However, the potential that white-tailed deer may be susceptible to sheep scrapie by a natural route presents an additional confounding factor to halting the spread of CWD. This leads to the additional speculations that
1) infected deer could serve as a reservoir to infect sheep with scrapie offering challenges to scrapie eradication efforts and
2) CWD spread need not remain geographically confined to current endemic areas, but could occur anywhere that sheep with scrapie and susceptible cervids cohabitate.
This work demonstrates for the first time that white-tailed deer are susceptible to sheep scrapie by intracerebral inoculation with a high attack rate and that the disease that results has similarities to CWD. These experiments will be repeated with a more natural route of inoculation to determine the likelihood of the potential transmission of sheep scrapie to white-tailed deer. If scrapie were to occur in white-tailed deer, results of this study indicate that it would be detected as a TSE, but may be difficult to differentiate from CWD without in-depth biochemical analysis.
2012
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA
snip...
The results of this study suggest that there are many similarities in the manifestation of CWD and scrapie in WTD after IC inoculation including early and widespread presence of PrPSc in lymphoid tissues, clinical signs of depression and weight loss progressing to wasting, and an incubation time of 21-23 months. Moreover, western blots (WB) done on brain material from the obex region have a molecular profile similar to CWD and distinct from tissues of the cerebrum or the scrapie inoculum. However, results of microscopic and IHC examination indicate that there are differences between the lesions expected in CWD and those that occur in deer with scrapie: amyloid plaques were not noted in any sections of brain examined from these deer and the pattern of immunoreactivity by IHC was diffuse rather than plaque-like.
*** After a natural route of exposure, 100% of WTD were susceptible to scrapie.
Deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 months PI. Tissues from these deer were positive for PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer exhibited two different molecular profiles: samples from obex resembled CWD whereas those from cerebrum were similar to the original scrapie inoculum. On further examination by WB using a panel of antibodies, the tissues from deer with scrapie exhibit properties differing from tissues either from sheep with scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are strongly immunoreactive when probed with mAb P4, however, samples from WTD with scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4 or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly immunoreactive and samples from WTD with scrapie are strongly positive. This work demonstrates that WTD are highly susceptible to sheep scrapie, but on first passage, scrapie in WTD is differentiable from CWD.
2011
*** After a natural route of exposure, 100% of white-tailed deer were susceptible to scrapie.
***> CWD TO PIGS <***
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Location: Virus and Prion Research
Title: Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
Author item Moore, Sarah item Kunkle, Robert item Kondru, Naveen item Manne, Sireesha item Smith, Jodi item Kanthasamy, Anumantha item West Greenlee, M item Greenlee, Justin
Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 3/15/2017 Publication Date: N/A Citation: N/A Interpretive Summary:
Technical Abstract: Aims: Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of cervids. We previously demonstrated that disease-associated prion protein (PrPSc) can be detected in the brain and retina from pigs challenged intracranially or orally with the CWD agent. In that study, neurological signs consistent with prion disease were observed only in one pig: an intracranially challenged pig that was euthanized at 64 months post-challenge. The purpose of this study was to use an antigen-capture immunoassay (EIA) and real-time quaking-induced conversion (QuIC) to determine whether PrPSc is present in lymphoid tissues from pigs challenged with the CWD agent.
Methods: At two months of age, crossbred pigs were challenged by the intracranial route (n=20), oral route (n=19), or were left unchallenged (n=9). At approximately 6 months of age, the time at which commercial pigs reach market weight, half of the pigs in each group were culled (<6 challenge="" groups="" month="" pigs="" remaining="" the="">6 month challenge groups) were allowed to incubate for up to 73 months post challenge (mpc). The retropharyngeal lymph node (RPLN) was screened for the presence of PrPSc by EIA and immunohistochemistry (IHC). The RPLN, palatine tonsil, and mesenteric lymph node (MLN) from 6-7 pigs per challenge group were also tested using EIA and QuIC.6>
Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 5="" 6="" at="" by="" detected="" eia.="" examined="" group="" in="" intracranial="" least="" lymphoid="" month="" months="" of="" one="" pigs="" positive="" prpsc="" quic="" the="" tissues="" was="">6 months group, 5/6 pigs in the oral <6 4="" and="" group="" months="" oral="">6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%). Conclusions:6>6>
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.
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. ...
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.
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.....
snip...see much more here ;
WEDNESDAY, APRIL 05, 2017
Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
WEDNESDAY, APRIL 05, 2017
*** Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease ***
cattle are highly susceptible to white-tailed deer CWD and mule deer CWD
***In contrast, cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions but no natural CWD infections in cattle have been reported (Sigurdson, 2008; Hamir et al., 2006). It is not known how susceptible humans are to CWD but given that the prion can be present in muscle, it is likely that humans have been exposed to the agent via consumption of venison (Sigurdson, 2008). Initial experimental research, however, suggests that human susceptibility to CWD is low and there may be a robust species barrier for CWD transmission to humans (Sigurdson, 2008). It is apparent, though, that CWD is affecting wild and farmed cervid populations in endemic areas with some deer populations decreasing as a result.
SNIP...
price of prion poker goes up for cwd to cattle;
Monday, April 04, 2016
*** Limited amplification of chronic wasting disease prions in the peripheral tissues of intracerebrally inoculated cattle ***
THURSDAY, MARCH 08, 2018
Cervid, Wild Hogs, Coyotes, Wolves, Cats, Rodents, Gut Piles and Scavengers, A Potential Risk as Regards Disease Transmission CWD TSE Prion
the tse prion aka mad cow type disease is not your normal pathogen.
The TSE prion disease survives ashing to 600 degrees celsius, that’s around 1112 degrees farenheit.
you cannot cook the TSE prion disease out of meat.
you can take the ash and mix it with saline and inject that ash into a mouse, and the mouse will go down with TSE.
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production as well.
the TSE prion agent also survives Simulated Wastewater Treatment Processes.
IN fact, you should also know that the TSE Prion agent will survive in the environment for years, if not decades.
you can bury it and it will not go away.
The TSE agent is capable of infected your water table i.e. Detection of protease-resistant cervid prion protein in water from a CWD-endemic area.
it’s not your ordinary pathogen you can just cook it out and be done with.
that’s what’s so worrisome about Iatrogenic mode of transmission, a simple autoclave will not kill this TSE prion agent.
1: J Neurol Neurosurg Psychiatry 1994 Jun;57(6):757-8
Transmission of Creutzfeldt-Jakob disease to a chimpanzee by electrodes contaminated during neurosurgery.
Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC.
Laboratory of Central Nervous System Studies, National Institute of
Neurological Disorders and Stroke, National Institutes of Health,
Bethesda, MD 20892.
Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.
PMID: 8006664 [PubMed - indexed for MEDLINE]
TITLE: PATHOLOGICAL FEATURES OF CHRONIC WASTING DISEASE IN REINDEER AND DEMONSTRATION OF HORIZONTAL TRANSMISSION
*** DECEMBER 2016 CDC EMERGING INFECTIOUS DISEASE JOURNAL CWD HORIZONTAL TRANSMISSION
*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years ***
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
Using in vitro Prion replication for high sensitive detection of prions and prionlike proteins and for understanding mechanisms of transmission.
Claudio Soto Mitchell Center for Alzheimer's diseases and related Brain disorders, Department of Neurology, University of Texas Medical School at Houston.
Prion and prion-like proteins are misfolded protein aggregates with the ability to selfpropagate to spread disease between cells, organs and in some cases across individuals. I n T r a n s m i s s i b l e s p o n g i f o r m encephalopathies (TSEs), prions are mostly composed by a misfolded form of the prion protein (PrPSc), which propagates by transmitting its misfolding to the normal prion protein (PrPC). The availability of a procedure to replicate prions in the laboratory may be important to study the mechanism of prion and prion-like spreading and to develop high sensitive detection of small quantities of misfolded proteins in biological fluids, tissues and environmental samples. Protein Misfolding Cyclic Amplification (PMCA) is a simple, fast and efficient methodology to mimic prion replication in the test tube. PMCA is a platform technology that may enable amplification of any prion-like misfolded protein aggregating through a seeding/nucleation process. In TSEs, PMCA is able to detect the equivalent of one single molecule of infectious PrPSc and propagate prions that maintain high infectivity, strain properties and species specificity. Using PMCA we have been able to detect PrPSc in blood and urine of experimentally infected animals and humans affected by vCJD with high sensitivity and specificity. Recently, we have expanded the principles of PMCA to amplify amyloid-beta (Aβ) and alphasynuclein (α-syn) aggregates implicated in Alzheimer's and Parkinson's diseases, respectively. Experiments are ongoing to study the utility of this technology to detect Aβ and α-syn aggregates in samples of CSF and blood from patients affected by these diseases.
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***Recently, we have been using PMCA to study the role of environmental prion contamination on the horizontal spreading of TSEs. These experiments have focused on the study of the interaction of prions with plants and environmentally relevant surfaces. Our results show that plants (both leaves and roots) bind tightly to prions present in brain extracts and excreta (urine and feces) and retain even small quantities of PrPSc for long periods of time. Strikingly, ingestion of prioncontaminated leaves and roots produced disease with a 100% attack rate and an incubation period not substantially longer than feeding animals directly with scrapie brain homogenate. Furthermore, plants can uptake prions from contaminated soil and transport them to different parts of the plant tissue (stem and leaves). Similarly, prions bind tightly to a variety of environmentally relevant surfaces, including stones, wood, metals, plastic, glass, cement, etc. Prion contaminated surfaces efficiently transmit prion disease when these materials were directly injected into the brain of animals and strikingly when the contaminated surfaces were just placed in the animal cage. These findings demonstrate that environmental materials can efficiently bind infectious prions and act as carriers of infectivity, suggesting that they may play an important role in the horizontal transmission of the disease.
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Since its invention 13 years ago, PMCA has helped to answer fundamental questions of prion propagation and has broad applications in research areas including the food industry, blood bank safety and human and veterinary disease diagnosis.
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PPo4-4:
Survival and Limited Spread of TSE Infectivity after Burial
Discussion Classical scrapie is an environmentally transmissible disease because it has been reported in naïve, supposedly previously unexposed sheep placed in pastures formerly occupied by scrapie-infected sheep (4, 19, 20).
Although the vector for disease transmission is not known, soil is likely to be an important reservoir for prions (2) where – based on studies in rodents – prions can adhere to minerals as a biologically active form (21) and remain infectious for more than 2 years (22).
Similarly, chronic wasting disease (CWD) has re-occurred in mule deer housed in paddocks used by infected deer 2 years earlier, which was assumed to be through foraging and soil consumption (23).
Our study suggested that the risk of acquiring scrapie infection was greater through exposure to contaminated wooden, plastic, and metal surfaces via water or food troughs, fencing, and hurdles than through grazing.
Drinking from a water trough used by the scrapie flock was sufficient to cause infection in sheep in a clean building.
Exposure to fences and other objects used for rubbing also led to infection, which supported the hypothesis that skin may be a vector for disease transmission (9).
The risk of these objects to cause infection was further demonstrated when 87% of 23 sheep presented with PrPSc in lymphoid tissue after grazing on one of the paddocks, which contained metal hurdles, a metal lamb creep and a water trough in contact with the scrapie flock up to 8 weeks earlier, whereas no infection had been demonstrated previously in sheep grazing on this paddock, when equipped with new fencing and field furniture.
When the contaminated furniture and fencing were removed, the infection rate dropped significantly to 8% of 12 sheep, with soil of the paddock as the most likely source of infection caused by shedding of prions from the scrapie-infected sheep in this paddock up to a week earlier.
This study also indicated that the level of contamination of field furniture sufficient to cause infection was dependent on two factors: stage of incubation period and time of last use by scrapie-infected sheep.
Drinking from a water trough that had been used by scrapie sheep in the predominantly pre-clinical phase did not appear to cause infection, whereas infection was shown in sheep drinking from the water trough used by scrapie sheep in the later stage of the disease.
It is possible that contamination occurred through shedding of prions in saliva, which may have contaminated the surface of the water trough and subsequently the water when it was refilled.
Contamination appeared to be sufficient to cause infection only if the trough was in contact with sheep that included clinical cases.
Indeed, there is an increased risk of bodily fluid infectivity with disease progression in scrapie (24) and CWD (25) based on PrPSc detection by sPMCA.
Although ultraviolet light and heat under natural conditions do not inactivate prions (26), furniture in contact with the scrapie flock, which was assumed to be sufficiently contaminated to cause infection, did not act as vector for disease if not used for 18 months, which suggest that the weathering process alone was sufficient to inactivate prions.
PrPSc detection by sPMCA is increasingly used as a surrogate for infectivity measurements by bioassay in sheep or mice.
In this reported study, however, the levels of PrPSc present in the environment were below the limit of detection of the sPMCA method, yet were still sufficient to cause infection of in-contact animals.
In the present study, the outdoor objects were removed from the infected flock 8 weeks prior to sampling and were positive by sPMCA at very low levels (2 out of 37 reactions).
As this sPMCA assay also yielded 2 positive reactions out of 139 in samples from the scrapie-free farm, the sPMCA assay could not detect PrPSc on any of the objects above the background of the assay.
False positive reactions with sPMCA at a low frequency associated with de novo formation of infectious prions have been reported (27, 28).
This is in contrast to our previous study where we demonstrated that outdoor objects that had been in contact with the scrapie-infected flock up to 20 days prior to sampling harbored PrPSc that was detectable by sPMCA analysis [4 out of 15 reactions (12)] and was significantly more positive by the assay compared to analogous samples from the scrapie-free farm.
This discrepancy could be due to the use of a different sPMCA substrate between the studies that may alter the efficiency of amplification of the environmental PrPSc.
In addition, the present study had a longer timeframe between the objects being in contact with the infected flock and sampling, which may affect the levels of extractable PrPSc.
Alternatively, there may be potentially patchy contamination of this furniture with PrPSc, which may have been missed by swabbing.
The failure of sPMCA to detect CWD-associated PrP in saliva from clinically affected deer despite confirmation of infectivity in saliva-inoculated transgenic mice was associated with as yet unidentified inhibitors in saliva (29), and it is possible that the sensitivity of sPMCA is affected by other substances in the tested material.
In addition, sampling of amplifiable PrPSc and subsequent detection by sPMCA may be more difficult from furniture exposed to weather, which is supported by the observation that PrPSc was detected by sPMCA more frequently in indoor than outdoor furniture (12).
A recent experimental study has demonstrated that repeated cycles of drying and wetting of prion-contaminated soil, equivalent to what is expected under natural weathering conditions, could reduce PMCA amplification efficiency and extend the incubation period in hamsters inoculated with soil samples (30).
This seems to apply also to this study even though the reduction in infectivity was more dramatic in the sPMCA assays than in the sheep model.
Sheep were not kept until clinical end-point, which would have enabled us to compare incubation periods, but the lack of infection in sheep exposed to furniture that had not been in contact with scrapie sheep for a longer time period supports the hypothesis that prion degradation and subsequent loss of infectivity occurs even under natural conditions.
In conclusion, the results in the current study indicate that removal of furniture that had been in contact with scrapie-infected animals should be recommended, particularly since cleaning and decontamination may not effectively remove scrapie infectivity (31), even though infectivity declines considerably if the pasture and the field furniture have not been in contact with scrapie-infected sheep for several months. As sPMCA failed to detect PrPSc in furniture that was subjected to weathering, even though exposure led to infection in sheep, this method may not always be reliable in predicting the risk of scrapie infection through environmental contamination.
These results suggest that the VRQ/VRQ sheep model may be more sensitive than sPMCA for the detection of environmentally associated scrapie, and suggest that extremely low levels of scrapie contamination are able to cause infection in susceptible sheep genotypes.
Keywords: classical scrapie, prion, transmissible spongiform encephalopathy, sheep, field furniture, reservoir, serial protein misfolding cyclic amplification
Wednesday, December 16, 2015
*** Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission ***
161: Prion soil binding may explain efficient horizontal CWD transmission
Nathaniel Denkers1, Davin Henderson1, Shannon Bartelt-Hunt2, Jason Bartz3 and Edward Hoover1
1Colorado State University; Fort Collins, Colorado USA
2University of Nebraska-Lincoln; Omaha, Nebraska USA
3Creighton University; Omaha, Nebraska USA
Background Chronic wasting disease (CWD) is unique due to the facile spread in nature. The interaction of excreted CWD prions and soil is a hypothesized contributor in environmental transmission. The present study examines whether and to what degree CWD prions bind to silty clay loam (SCL) using an adapted version of real-time quaking-induced conversion (RT-QuIC) methodology.
Materials and Methods Varying amounts (50–3.12 mg) of SCL were incubated with 1 mL-serial dilutions of CWD (+), CWD (−), or no brain homogenate (BH). Samples were centrifuged, washed, diluted 1:10 in 0.1% SDS, and 2.5 uL seeded in RT-QuIC assays employing recombinant Syrian hamster prion PrP substrate. Multiple well replicates of sample and supernatant fractions were assayed for positive seeding activity (recorded as thioflavin T fluorescence emission; 480 nm). Samples were considered positive if they crossed a threshold of 25,000. Reaction rates (RR) were calculated, averaged, and expressed as 1/RR.
Results Positive seeding activity was detected for most SCL samples incubated with CWD (+) BH dilutions. Higher SCL concentrations (50 mg) produced low fluorescent readings due to optical interference. Lower SCL concentrations (6.25 mg) produced minimal optical interference and removed the vast majority of seeding activity from CWD+ BH in a concentration-dependent manner; determined by seeding activity in residual BH supernatants. Control SCL and supernatants produced minimal false-positive reactions (8 of 240 replicates; 3.3%). We estimated the prion binding capacity of SCL to be 0.16 ng/mg.
Conclusion Silty clay loam exhibits highly efficient prion binding, inferring a durable environmental reservoir, and an efficient mechanism for indirect horizontal CWD transmission.
TSE Scrapie, CWD, BSE, Prion, Soil
Clay content and pH: soil characteristic associations with the persistent presence of chronic wasting disease in northern Illinois
Sheena J. Dorak, Michelle L. Green, Michelle M. Wander, Marilyn O. Ruiz, Michael G. Buhnerkempe, Ting Tian, Jan E. Novakofski & Nohra E. Mateus-Pinilla
Scientific Reportsvolume 7, Article number: 18062(2017) doi:10.1038/s41598-017-18321-x
Download Citation
Ecological epidemiology Ecological modelling Infectious diseases Prions
Received: 21 August 2017
Accepted: 08 December 2017
Published online: 22 December 2017
Abstract
Environmental reservoirs are important to infectious disease transmission and persistence, but empirical analyses are relatively few. The natural environment is a reservoir for prions that cause chronic wasting disease (CWD) and influences the risk of transmission to susceptible cervids. Soil is one environmental component demonstrated to affect prion infectivity and persistence. Here we provide the first landscape predictive model for CWD based solely on soil characteristics. We built a boosted regression tree model to predict the probability of the persistent presence of CWD in a region of northern Illinois using CWD surveillance in deer and soils data. We evaluated the outcome for possible pathways by which soil characteristics may increase the probability of CWD transmission via environmental contamination. Soil clay content and pH were the most important predictive soil characteristics of the persistent presence of CWD. The results suggest that exposure to prions in the environment is greater where percent clay is less than 18% and soil pH is greater than 6.6. These characteristics could alter availability of prions immobilized in soil and contribute to the environmental risk factors involved in the epidemiological complexity of CWD infection in natural populations of white-tailed deer.
Oral Transmissibility of Prion Disease Is Enhanced by Binding to Soil Particles
Author Summary
Transmissible spongiform encephalopathies (TSEs) are a group of incurable neurological diseases likely caused by a misfolded form of the prion protein. TSEs include scrapie in sheep, bovine spongiform encephalopathy (‘‘mad cow’’ disease) in cattle, chronic wasting disease in deer and elk, and Creutzfeldt-Jakob disease in humans. Scrapie and chronic wasting disease are unique among TSEs because they can be transmitted between animals, and the disease agents appear to persist in environments previously inhabited by infected animals. Soil has been hypothesized to act as a reservoir of infectivity and to bind the infectious agent. In the current study, we orally dosed experimental animals with a common clay mineral, montmorillonite, or whole soils laden with infectious prions, and compared the transmissibility to unbound agent. We found that prions bound to montmorillonite and whole soils remained orally infectious, and, in most cases, increased the oral transmission of disease compared to the unbound agent. The results presented in this study suggest that soil may contribute to environmental spread of TSEs by increasing the transmissibility of small amounts of infectious agent in the environment.
tse prion soil
cwd tse prion and soil, see more ;
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