Open Access
Published: 31 August 2021
Classical BSE prions emerge from asymptomatic pigs challenged with atypical/Nor98 scrapie
Belén Marín, Alicia Otero, Séverine Lugan, Juan Carlos Espinosa, Alba Marín-Moreno, Enric Vidal, Carlos Hedman, Antonio Romero, Martí Pumarola, Juan J. Badiola, Juan María Torres, Olivier Andréoletti & Rosa Bolea
Scientific Reports volume 11, Article number: 17428 (2021) Cite this article
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Abstract
Pigs are susceptible to infection with the classical bovine spongiform encephalopathy (C-BSE) agent following experimental inoculation, and PrPSc accumulation was detected in porcine tissues after the inoculation of certain scrapie and chronic wasting disease isolates. However, a robust transmission barrier has been described in this species and, although they were exposed to C-BSE agent in many European countries, no cases of natural transmissible spongiform encephalopathies (TSE) infections have been reported in pigs. Transmission of atypical scrapie to bovinized mice resulted in the emergence of C-BSE prions. Here, we conducted a study to determine if pigs are susceptible to atypical scrapie. To this end, 12, 8–9-month-old minipigs were intracerebrally inoculated with two atypical scrapie sources. Animals were euthanized between 22- and 72-months post inoculation without clinical signs of TSE. All pigs tested negative for PrPSc accumulation by enzyme immunoassay, immunohistochemistry, western blotting and bioassay in porcine PrP mice. Surprisingly, in vitro protein misfolding cyclic amplification demonstrated the presence of C-BSE prions in different brain areas from seven pigs inoculated with both atypical scrapie isolates. Our results suggest that pigs exposed to atypical scrapie prions could become a reservoir for C-BSE and corroborate that C-BSE prions emerge during interspecies passage of atypical scrapie.
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In conclusion, our findings suggest that, although pigs present a strong transmission barrier against the propagation of atypical scrapie, they can propagate low levels of C-BSE prions. The prevalence of atypical scrapie and the presence of infectivity in tissues from atypical scrapie infected sheep are underestimated24,25. Given that pigs have demonstrated being susceptible to other prion diseases, and to propagate prions without showing signs of disease, the measures implemented to ban the inclusion of ruminant proteins in livestock feed must not be interrupted.
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: Experimental transmission of the chronic wasting disease agent to swine after oral or intracranial inoculation
Author item MOORE, SARAH - Orise Fellow item WEST GREENLEE, M - Iowa State University item KONDRU, NAVEEN - Iowa State University item MANNE, SIREESHA - Iowa State University item Smith, Jodi item Kunkle, Robert item KANTHASAMY, ANUMANTHA - Iowa State University item Greenlee, Justin Submitted to: Journal of Virology Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/6/2017 Publication Date: 9/12/2017
Citation: Moore, S.J., West Greenlee, M.H., Kondru, N., Manne, S., Smith, J.D., Kunkle, R.A., Kanthasamy, A., Greenlee, J.J. 2017. Experimental transmission of the chronic wasting disease agent to swine after oral or intracranial inoculation. Journal of Virology. 91(19):e00926-17. https://doi.org/10.1128/JVI.00926-17.
Interpretive Summary: Chronic wasting disease (CWD) is a fatal disease of wild and captive deer and elk that causes damaging changes in the brain. The infectious agent is an abnormal protein called a prion that has misfolded from its normal state. Whether CWD can transmit to swine is unknown. This study evaluated the potential of pigs to develop CWD after either intracranial or oral inoculation. Our data indicates that swine do accumulate the abnormal prion protein associated with CWD after intracranial or oral inoculation. Further, there was evidence of abnormal prion protein accumulation in lymph nodes. Currently, swine rations in the U.S. could contain animal derived components including materials from deer or elk. In addition, feral swine could be exposed to infected carcasses in areas where CWD is present in wildlife populations. This information is useful to wildlife managers and individuals in the swine and captive cervid industries. These findings could impact future regulations for the disposal of offal from deer and elk slaughtered in commercial operations. U.S. regulators should carefully consider the new information from this study before relaxing feed ban standards designed to control potentially feed borne prion diseases.
Technical Abstract: Chronic wasting disease (CWD) is a naturally occurring, fatal neurodegenerative disease of cervids. The potential for swine to serve as a host for the agent of chronic wasting disease is unknown. The purpose of this study was to investigate the susceptibility of swine to the CWD agent following oral or intracranial experimental inoculation. Crossbred piglets were assigned to one of three groups: intracranially inoculated (n=20), orally inoculated (n=19), or non-inoculated (n=9). At approximately the age at which commercial pigs reach market weight, half of the pigs in each group were culled ('market weight' groups). The remaining pigs ('aged' groups) were allowed to incubate for up to 73 months post inoculation (MPI). Tissues collected at necropsy were examined for disease-associated prion protein (PrPSc) by western blotting (WB), antigen-capture immunoassay (EIA), immunohistochemistry (IHC) and in vitro real-time quaking induced conversion (RT-QuIC). Brain samples from selected pigs were also bioassayed in mice expressing porcine prion protein. Four intracranially inoculated aged pigs and one orally inoculated aged pig were positive by EIA, IHC and/or WB. Using RT-QuIC, PrPSc was detected in lymphoid and/or brain tissue from pigs in all inoculated groups. Bioassay was positive in 4 out of 5 pigs assayed. This study demonstrates that pigs can serve as hosts for CWD, though with scant PrPSc accumulation requiring sensitive detection methods. Detection of infectivity in orally inoculated pigs using mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity.
12 September 2017
Experimental Transmission of the Chronic Wasting Disease Agent to Swine after Oral or Intracranial Inoculation
Authors: S. Jo Moore, M. Heather West Greenlee, Naveen Kondru, Sireesha Manne, Jodi D. Smith, Robert A. Kunkle, Anumantha Kanthasamy, and Justin J. Greenlee
AUTHORS INFO & AFFILIATIONS
Volume 91, Number 19
1 October 2017
ABSTRACT
ABSTRACT
Chronic wasting disease (CWD) is a naturally occurring, fatal neurodegenerative disease of cervids. The potential for swine to serve as hosts for the agent of CWD is unknown. The purpose of this study was to investigate the susceptibility of swine to the CWD agent following experimental oral or intracranial inoculation. Crossbred piglets were assigned to three groups, intracranially inoculated (n = 20), orally inoculated (n = 19), and noninoculated (n = 9). At approximately the age at which commercial pigs reach market weight, half of the pigs in each group were culled (“market weight” groups). The remaining pigs (“aged” groups) were allowed to incubate for up to 73 months postinoculation (mpi). Tissues collected at necropsy were examined for disease-associated prion protein (PrPSc) by Western blotting (WB), antigen capture enzyme immunoassay (EIA), immunohistochemistry (IHC), and in vitro real-time quaking-induced conversion (RT-QuIC). Brain samples from selected pigs were also bioassayed in mice expressing porcine prion protein. Four intracranially inoculated aged pigs and one orally inoculated aged pig were positive by EIA, IHC, and/or WB. By RT-QuIC, PrPSc was detected in lymphoid and/or brain tissue from one or more pigs in each inoculated group. The bioassay was positive in four out of five pigs assayed. This study demonstrates that pigs can support low-level amplification of CWD prions, although the species barrier to CWD infection is relatively high. However, detection of infectivity in orally inoculated pigs with a mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity. IMPORTANCE We challenged domestic swine with the chronic wasting disease agent by inoculation directly into the brain (intracranially) or by oral gavage (orally). Disease-associated prion protein (PrPSc) was detected in brain and lymphoid tissues from intracranially and orally inoculated pigs as early as 8 months of age (6 months postinoculation). Only one pig developed clinical neurologic signs suggestive of prion disease. The amount of PrPSc in the brains and lymphoid tissues of positive pigs was small, especially in orally inoculated pigs. Regardless, positive results obtained with orally inoculated pigs suggest that it may be possible for swine to serve as a reservoir for prion disease under natural conditions.
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
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.
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP
Author item MOORE, S - Orise Fellow item Kokemuller, Robyn item WEST-GREENLEE, M - Iowa State University item BALKEMA-BUSCHMANN, ANNE - Friedrich-Loeffler-institut item GROSCHUP, MARTIN - Friedrich-Loeffler-institut item Greenlee, Justin Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 5/10/2018 Publication Date: 5/22/2018 Citation: Moore, S.J., Kokemuller, R.D., West-Greenlee, M.H., Balkema-Buschmann, A., Groschup, M.H., Greenlee, J.J. 2018. The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP. Prion 2018, Santiago de Compostela, Spain, May 22-25, 2018. Paper No. WA15, page 44.
Interpretive Summary:
The successful transmission of pig-passaged CWD to Tg40 mice reported here suggests that passage of the CWD agent through pigs results in a change of the transmission characteristics which reduces the transmission barrier of Tg40 mice to the CWD agent. If this biological behavior is recapitulated in the original host species, passage of the CWD agent through pigs could potentially lead to increased pathogenicity of the CWD agent in humans.
cwd scrapie pigs oral routes
***> However, at 51 months of incubation or greater, 5 animals were positive by one or more diagnostic methods. Furthermore, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study) suggesting that swine are potential hosts for the agent of scrapie. <***
>*** Although the current U.S. feed ban is based on keeping tissues from TSE infected cattle from contaminating animal feed, swine rations in the U.S. could contain animal derived components including materials from scrapie infected sheep and goats. These results indicating the susceptibility of pigs to sheep scrapie, 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. <***
***> 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 month group was positive by EIA. PrPSc was detected by QuIC in at least one of the lymphoid tissues examined in 5/6 pigs in the intracranial <6 months group, 6/7 intracranial >6 months group, 5/6 pigs in the oral <6 months group, and 4/6 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: 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.
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.
CONFIDENTIAL
EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY
LINE TO TAKE
3. If questions on pharmaceuticals are raised at the Press conference, the suggested line to take is as follows:-
"There are no medicinal products licensed for use on the market which make use of UK-derived porcine tissues with which any hypothetical “high risk" ‘might be associated. The results of the recent experimental work at the CSM will be carefully examined by the CSM‘s Working Group on spongiform encephalopathy at its next meeting.
DO Hagger RM 1533 MT Ext 3201
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.
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. ...
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. ...
But it would be easier for us if pharmaceuticals/devices are not directly mentioned at all. ...
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.....
America BSE 589.2001 FEED REGULATIONS, BSE SURVEILLANCE, BSE TESTING, and CJD TSE Prion
so far, we have been lucky. to date, with the science at hand, no cwd transmitted to cattle, that has been documented, TO DATE, WITH THE SCIENCE AT HAND, it's not to say it has not already happened, just like with zoonosis of cwd i.e. molecular transmission studies have shown that cwd transmission to humans would look like sporadic cjd, NOT nvCJD or what they call now vCJD. the other thing is virulence and or horizontal transmission. this is very concerning with the recent fact of what seems to be a large outbreak of a new tse prion disease in camels in Africa. there is much concern now with hay, straw, grains, and such, with the cwd tse prion endemic countries USA, Canada. what is of greatest concern is the different strains of cwd, and the virulence there from? this thing (cwd) keeps mutating to different strains, and to different species, the bigger the chance of one of these strains that WILL TRANSMIT TO CATTLE OR HUMANS, and that it is documented (i believe both has already occured imo with scienct to date). with that said, a few things to ponder, and i am still very concerned with, the animal feed. we now know from transmission studies that cwd and scrapie will transmit to pigs by oral routes. the atypical bse strains will transmit by oral routes. i don't mean to keep kicking a mad cow, just look at the science;
***> cattle, pigs, sheep, cwd, tse, prion, oh my!
***> 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).
Sheep and cattle may be exposed to CWD via common grazing areas with affected deer but so far, appear to be poorly susceptible to mule deer CWD (Sigurdson, 2008). 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 suggests that human susceptibility to CWD is low and there may be a robust species barrier for CWD transmission to humans (Sigurdson, 2008), however the risk appetite for a public health threat may still find this level unacceptable.
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
snip.....
In the USA, under the Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law. Animals considered at high risk for CWD include:
1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and
2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.
Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.
The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES.
It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.
Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.
There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.
snip.....
36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011). The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE). Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison. snip..... The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).
snip.....
In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion. snip..... In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible... For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.
snip.....
Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.
snip.....
***> READ THIS VERY, VERY, CAREFULLY, AUGUST 1997 MAD COW FEED BAN WAS A SHAM, AS I HAVE STATED SINCE 1997! 3 FAILSAFES THE FDA ET AL PREACHED AS IF IT WERE THE GOSPEL, IN TERMS OF MAD COW BSE DISEASE IN USA, AND WHY IT IS/WAS/NOT A PROBLEM FOR THE USA, and those are;
BSE TESTING (failed terribly and proven to be a sham)
BSE SURVEILLANCE (failed terribly and proven to be a sham)
BSE 589.2001 FEED REGULATIONS (another colossal failure, and proven to be a sham)
these are facts folks. trump et al just admitted it with the feed ban.
see;
FDA Reports on VFD Compliance
John Maday
August 30, 2019 09:46 AM VFD-Form 007 (640x427)
Before and after the current Veterinary Feed Directive rules took full effect in January, 2017, the FDA focused primarily on education and outreach. ( John Maday ) Before and after the current Veterinary Feed Directive (VFD) rules took full effect in January, 2017, the FDA focused primarily on education and outreach to help feed mills, veterinarians and producers understand and comply with the requirements. Since then, FDA has gradually increased the number of VFD inspections and initiated enforcement actions when necessary. On August 29, FDA released its first report on inspection and compliance activities. The report, titled “Summary Assessment of Veterinary Feed Directive Compliance Activities Conducted in Fiscal Years 2016 – 2018,” is available online.
FDA Reports on VFD Compliance
John Maday
August 30, 2019 09:46 AM VFD-Form 007 (640x427)
Before and after the current Veterinary Feed Directive rules took full effect in January, 2017, the FDA focused primarily on education and outreach. ( John Maday )
Before and after the current Veterinary Feed Directive (VFD) rules took full effect in January, 2017, the FDA focused primarily on education and outreach to help feed mills, veterinarians and producers understand and comply with the requirements. Since then, FDA has gradually increased the number of VFD inspections and initiated enforcement actions when necessary.
On August 29, FDA released its first report on inspection and compliance activities. The report, titled “Summary Assessment of Veterinary Feed Directive Compliance Activities Conducted in Fiscal Years 2016 – 2018,” is available online.
Overall, the FDA reports a high level of compliance across the affected livestock-industry sectors.
In fiscal year 2016, FDA began a small, three-part pilot inspection program that began with inspectors visiting feed distributors to review randomly selected VFD documents. The inspectors then selected one VFD at the distributor and conducted further inspections of the veterinarian and producer (client) named on that VFD.
In fiscal years 2017 and 2018, FDA continued those three-part inspections and expanded the program to include state feed regulatory partners. In fiscal year 2017, state personnel inspected VFD distributors and reviewed selected VFDs for compliance with the requirements. In 2018, those state inspectors began conducting three-part inspections, similar to those conducted by the FDA investigators. With state inspectors contributing, the number of VFD inspections increased from 57 in 2016 to 130 in 2017 and 269 during 2018.
Of the 269 inspections during 2018, 230 required no action, 38 indicated voluntary action and just one indicated official enforcement action.
Key findings in the report include:
Distributors (2018)
Distributor had notified FDA of their intent to distribute VFD feeds -- 94.8%
Distributors who distributed a VFD feed that complied with the terms of the VFD -- 91.5%
Distributors who manufacture VFD feed: Drug inventory or production records showed the correct amount of drug was added to the feed for the VFD reviewed -- 96.7%
Distributors who manufacture VFD feed: Labels and formulas matched the VFD reviewed -- 91.0%
Distributor’s VFD feed labels contained the VFD caution statement -- 77.2%
Veterinarians
Veterinarians had an active license in the state where the VFD feed authorized on the VFD order(s) is being fed -- 100%
VFDs included veterinarians’ electronic or written signature -- 98.6%
VFDs included the withdrawal time, special instructions, and/or cautionary statements -- 95.3%
Producers
Client did not feed VFD feed beyond the expiration date on the VFD -- 100%
Client fed VFD feed to the animals authorized on the VFD (number, species, and/or production class) -- 100%
Client fed VFD feed for the duration identified on the VFD -- 100%
Client complied with the special instructions on the VFD -- 100%
FDA issued just one warning letter following inspections during fiscal year 2018, for a feed mill that “adulterated and misbranded VFD feed by distributing VFD feed to other distributors without first receiving an acknowledgment letter, in addition to adulterating and misbranding medicated and non-medicated feed for other reasons.”
In its report, FDA reminds stakeholders that VFD medicated feeds must be used in according to the approved conditions of use and must be under the oversight of a licensed veterinarian and consistent with a lawful VFD order. The agency intends to continue monitoring compliance, and to provide education, but FDA will also use enforcement strategies when voluntary compliance with the VFD final rule requirements is not achieved.
See the full summary report from FDA.
For more on the VFD rules and compliance, see these articles from BovineVetOnline.com.
VFD Audits: What to Expect
VFD Audits: Start with the Feed Distributor
FDA Draft Guidance Updates VFD Q&A
SUNDAY, SEPTEMBER 1, 2019
***> FDA Reports on VFD Compliance
TUESDAY, APRIL 18, 2017
***> EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP ***
THURSDAY, SEPTEMBER 26, 2019
Veterinary Biologics Guideline 3.32E: Guideline for minimising the risk of introducing transmissible spongiform encephalopathy prions and other infectious agents through veterinary biologics
U.S.A. 50 STATE BSE MAD COW CONFERENCE CALL Jan. 9, 2001
Subject: BSE--U.S. 50 STATE CONFERENCE CALL Jan. 9, 2001
Date: Tue, 9 Jan 2001 16:49:00 -0800
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy
snip...
[host Richard Barns] and now a question from Terry S. Singeltary of CJD Watch.
[TSS] yes, thank you, U.S. cattle, what kind of guarantee can you give for serum or tissue donor herds?
[no answer, you could hear in the back ground, mumbling and 'we can't. have him ask the question again.]
[host Richard] could you repeat the question?
[TSS] U.S. cattle, what kind of guarantee can you give for serum or tissue donor herds?
[not sure whom ask this] what group are you with?
[TSS] CJD Watch, my Mom died from hvCJD and we are tracking CJD world-wide.
[not sure who is speaking] could you please disconnect Mr. Singeltary
[TSS] you are not going to answer my question?
[not sure whom speaking] NO
snip...see full archive and more of this;
3.2.1.2 Non‐cervid domestic species
The remarkably high rate of natural CWD transmission in the ongoing NA epidemics raises the question of the risk to livestock grazing on CWD‐contaminated shared rangeland and subsequently developing a novel CWD‐related prion disease. This issue has been investigated by transmitting CWD via experimental challenge to cattle, sheep and pigs and to tg mouse lines expressing the relevant species PrP.
For cattle challenged with CWD, PrPSc was detected in approximately 40% of intracerebrally inoculated animals (Hamir et al., 2005, 2006a, 2007). Tg mice expressing bovine PrP have also been challenged with CWD and while published studies have negative outcomes (Tamguney et al., 2009b), unpublished data provided for the purposes of this Opinion indicate that some transmission of individual isolates to bovinised mice is possible (Table 1).
In small ruminant recipients, a low rate of transmission was reported between 35 and 72 months post‐infection (mpi) in ARQ/ARQ and ARQ/VRQ sheep intracerebrally challenged with mule deer CWD (Hamir et al., 2006b), while two out of two ARQ/ARQ sheep intracerebrally inoculated with elk CWD developed clinical disease after 28 mpi (Madsen‐Bouterse et al., 2016). However, tg mice expressing ARQ sheep PrP were resistant (Tamguney et al., 2006) and tg mice expressing the VRQ PrP allele were poorly susceptible to clinical disease (Beringue et al., 2012; Madsen‐Bouterse et al., 2016). In contrast, tg mice expressing VRQ sheep PrP challenged with CWD have resulted in highly efficient, life‐long asymptomatic replication of these prions in the spleen tissue (Beringue et al., 2012).
A recent study investigated the potential for swine to serve as hosts of the CWD agent(s) by intracerebral or oral challenge of crossbred piglets (Moore et al., 2016b, 2017). Pigs sacrificed at 6 mpi, approximately the age at which pigs reach market weight, were clinically healthy and negative by diagnostic tests, although low‐level CWD agent replication could be detected in the CNS by bioassay in tg cervinised mice. Among pigs that were incubated for up to 73 mpi, some gave diagnostic evidence of CWD replication in the brain between 42 and 72 mpi. Importantly, this was observed also in one orally challenged pig at 64 mpi and the presence of low‐level CWD replication was confirmed by mouse bioassay. The authors of this study argued that pigs can support low‐level amplification of CWD prions, although the species barrier to CWD infection is relatively high and that the detection of infectivity in orally inoculated pigs with a mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity.
Working Document on Camel Prion Disease (CPrD) 14/09/2020
Content: I. Introduction II. Camel prion disease III. Case definition IV. Epidemiological surveillance V. Biosafety VI. Capacity building VII. Early warning and response VIII. Risk factors IX. Knowledge Gaps X. References
I. Introduction
Camel prion disease (CPrD) is the last disease described in the family of prion diseases [1]. To date, it has been recognized only in Middle East of Algeria and in the neighboring region of Tunisia [2]. However, there are no known other initiatives of prion diseases surveillance in camels worldwide. CPrD might actually be limited to the already known geographic area in North Africa or spread undetected in other Countries, as a consequence of the movements of dromedaries along trans-Saharan commercial routes, the import/export trade flows of living animals and the traditional extensive and nomadic rearing systems.
According to the discussions in recent meetings of REMESA and OIE which indicated the need to extend the knowledge on CPrD spread in Countries where camels are extensively reared and considered as a part of the domestic livestock [3], and according to the initiative from CAMENET member countries to assess the risk in the CAMENET region, this working document aims to provide countries with the main technical and scientific knowledge necessary to implement surveillance programs on camel prion disease in its own territory. Basic information contained in this document may also be helpful for the possible design of contingency plans.
The present working document is an 'alive' document. It should be regularly reviewed and updated as further information becomes available.
II. Camel prion disease1
Camel prion disease (CPrD) was diagnosed in 2018 in three adult camels showing clinical signs at the ante-mortem inspection at an abattoir in the region of Ouargla (Algeria) [1]. According to the published report symptoms suggesting prion disease occurred in 3.1% of dromedaries brought for slaughter to the Ouargla abattoir in 2015–2016. More recently, in 2019, the same disease was reported in the region of Tataouine (Tunisia) [2]. CPrD adds to the group of animal prion diseases,
1 Modified from the OIE Bulletin: https://oiebulletin.com/wp-content/uploads/2019/12/OIE-NewsDecember-2019-Camel-priondisease.pdf?utm_source=World+Organisation+for+Animal+Health+%E2%80%93+OIE+Bulletin&utm_c ampaign=388d499799- EMAIL_CAMPAIGN_2019_12_05_09_06&utm_medium=email&utm_term=0_7694a173d1- 388d499799-54758659
including scrapie in sheep and goats, chronic wasting disease (CWD) in cervids and Bovine spongiform encephalopathy (BSE) in cattle. As of today, very limited epidemiological information is available about the prevalence, geographical distribution and mode of transmission of the disease.
The involvement of lymphoid tissue in prion replication, observed both in the Algerian and Tunisian cases [1,2], is suggestive of a peripheral pathogenesis, which is thought to be a prerequisite for prion shedding into the environment. As with other animal prion diseases, such as scrapie and CWD, in which lymphoid tissues are extensively involved and horizontal transmission occurs efficiently under natural conditions, the detection of prion proteins in lymph nodes is suggestive of the infectious nature of CPrD and concurs to hypothesize the potential impact of CPrD on animal health. No evidence is currently available with which to argue for the relevance of CPrD for human health. However, no absolute species barrier exists in prion diseases and minimizing the exposure of humans to prion-infected animal products is an essential aspect of public health protection.
The worldwide camel population is ~35 million head, 88% of which is found in Africa [4]. The camel farming system is evolving rapidly, and these animals represent vital sources of meat, milk and transportation for millions of people living in the most arid regions of the world. This makes it necessary to assess the risk for animal and human health and to develop evidence-based policies to control and limit the spread of the disease in animals, and to minimize human exposure. As a first step, the awareness of Veterinary Services about CPrD and its diagnostic capacity needs to be improved in all countries where dromedaries are part of the domestic livestock.
Since the first description of CPrD, the OIE promoted discussions on the impact of this new disease through the OIE Scientific Commission for Animal Diseases (Scientific Commission). It evaluated if CPrD should be considered an ‘emerging disease’ based on the criteria listed in the Terrestrial Animal Health Code. The OIE Scientific Commission noted that limited surveillance data were available on the prevalence of CPrD and that the evidence was not enough to measure, at that time, the impact of the disease on animal or public health. Therefore, it was concluded that, with the current knowledge, CPrD did not currently meet the criteria to be considered an emerging disease.
Nonetheless, it was emphasized that CPrD should be considered as a new disease not to be overlooked and called for the collection of further scientific evidence through research and surveillance in the affected countries and in countries with dromedary camel populations to measure the impact of the disease. As new scientific evidence becomes available, the OIE Scientific Commission will reassess whether this disease should be considered as an emerging disease. At the regional level, CPrD was first discussed in the 18th Joint Permanent Committee of the Mediterranean Animal Health Network (REMESA) held in Cairo, Egypt, in June 2019 and at the 15th Conference of the OIE Regional Commission for the Middle East in November. During this conference, the CAMENET launched a wide-ranging proposal for training, coordinated surveillance and research on CPrD. In addition, the ERFAN (Enhancing Research for Africa Network), a platform aimed at enhancing scientific cooperation between Africa and Italy, during its 2nd ERFAN meeting for North Africa, presented a project on CPrD with the objective of increasing CPrD coordinated surveillance in North Africa.
The OIE, through its Reference Laboratories for prion diseases, and by involving the above scientific initiatives, is keeping a close watch on the evolution of the disease to gather scientific evidence and to allow a proper and more thorough assessment of the risk associated with this novel disease.
III. Case definition
snip...see;
Tuesday, April 27, 2021
Working Document on Camel Prion Disease (CPrD) 14/09/2020
TUESDAY, JUNE 8, 2021
***> Bovine spongiform encephalopathy: the effect of oral exposure dose on attack rate and incubation period in cattle
WEDNESDAY, MARCH 24, 2021
USDA Animal and Plant Health Inspection Service 2020 IMPACT REPORT BSE TSE Prion Testing and Surveillance MIA
***> AS is considered more likely (subjective probability range 50–66%) that AS is a non-contagious, rather than a contagious, disease.
ATYPICAL SCRAPIE ROUGHLY HAS 50 50 CHANCE ATYPICAL SCRAPIE IS CONTAGIOUS, AS NON-CONTAGIOUS, TAKE YOUR PICK, BUT I SAID IT LONG AGO WHEN USDA OIE ET AL MADE ATYPICAL SCRAPIE A LEGAL TRADING COMODITY, I SAID YOUR PUTTING THE CART BEFORE THE HORSE, AND THAT'S EXACTLY WHAT THEY DID, and it's called in Texas, TEXAS TSE PRION HOLDEM POKER, WHO'S ALL IN $$$
THURSDAY, JULY 8, 2021
EFSA Scientific report on the analysis of the 2‐year compulsory intensified monitoring of atypical scrapie
MONDAY, JUNE 28, 2021
BSE can propagate in sheep co‑infected or pre‑infected with scrapie
THURSDAY, DECEMBER 31, 2020
Autoclave treatment of the classical scrapie agent US No. 13-7 and experimental inoculation to susceptible VRQ/ARQ sheep via the oral route results in decreased transmission efficiency
WEDNESDAY, MAY 29, 2019
***> Incomplete inactivation of atypical scrapie following recommended autoclave decontamination procedures
USDA HERE'S YOUR SIGN!
SATURDAY, AUGUST 16, 2008
Qualitative Analysis of BSE Risk Factors in the United States February 13, 2000 at 3:37 pm PST (BSE red book)
Sunday, January 10, 2021
APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087] Singeltary Submission June 17, 2019
APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087] Singeltary Submission
Greetings APHIS et al,
I would kindly like to comment on APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087], and my comments are as follows, with the latest peer review and transmission studies as references of evidence.
THE OIE/USDA BSE Minimal Risk Region MRR is nothing more than free pass to import and export the Transmissible Spongiform Encephalopathy TSE Prion disease. December 2003, when the USDA et al lost it's supposedly 'GOLD CARD' ie BSE FREE STATUS (that was based on nothing more than not looking and not finding BSE), once the USA lost it's gold card BSE Free status, the USDA OIE et al worked hard and fast to change the BSE Geographical Risk Statuses i.e. the BSE GBR's, and replaced it with the BSE MRR policy, the legal tool to trade mad cow type disease TSE Prion Globally. The USA is doing just what the UK did, when they shipped mad cow disease around the world, except with the BSE MRR policy, it's now legal.
Also, the whole concept of the BSE MRR policy is based on a false pretense, that atypical BSE is not transmissible, and that only typical c-BSE is transmissible via feed. This notion that atypical BSE TSE Prion is an old age cow disease that is not infectious is absolutely false, there is NO science to show this, and on the contrary, we now know that atypical BSE will transmit by ORAL ROUTES, but even much more concerning now, recent science has shown that Chronic Wasting Disease CWD TSE Prion in deer and elk which is rampant with no stopping is sight in the USA, and Scrapie TSE Prion in sheep and goat, will transmit to PIGS by oral routes, this is our worst nightmare, showing even more risk factors for the USA FDA PART 589 TSE PRION FEED ban.
The FDA PART 589 TSE PRION FEED ban has failed terribly bad, and is still failing, since August 1997. there is tonnage and tonnage of banned potential mad cow feed that went into commerce, and still is, with one decade, 10 YEARS, post August 1997 FDA PART 589 TSE PRION FEED ban, 2007, with 10,000,000 POUNDS, with REASON, Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement. you can see all these feed ban warning letters and tonnage of mad cow feed in commerce, year after year, that is not accessible on the internet anymore like it use to be, you can see history of the FDA failure August 1997 FDA PART 589 TSE PRION FEED ban here, but remember this, we have a new outbreak of TSE Prion disease in a new livestock species, the camel, and this too is very worrisome.
WITH the OIE and the USDA et al weakening the global TSE prion surveillance, by not classifying the atypical Scrapie as TSE Prion disease, and the notion that they want to do the same thing with typical scrapie and atypical BSE, it's just not scientific.
WE MUST abolish the BSE MRR policy, go back to the BSE GBR risk assessments by country, and enhance them to include all strains of TSE Prion disease in all species. With Chronic Wasting CWD TSE Prion disease spreading in Europe, now including, Norway, Finland, Sweden, also in Korea, Canada and the USA, and the TSE Prion in Camels, the fact the the USA is feeding potentially CWD, Scrapie, BSE, typical and atypical, to other animals, and shipping both this feed and or live animals or even grains around the globe, potentially exposed or infected with the TSE Prion. this APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087], under it's present definition, does NOT show the true risk of the TSE Prion in any country. as i said, it's nothing more than a legal tool to trade the TSE Prion around the globe, nothing but ink on paper.
AS long as the BSE MRR policy stays in effect, TSE Prion disease will continued to be bought and sold as food for both humans and animals around the globe, and the future ramifications from friendly fire there from, i.e. iatrogenic exposure and transmission there from from all of the above, should not be underestimated. ...
2.3.2. New evidence on the zoonotic potential of atypical BSE and atypical scrapie prion strains
PLEASE NOTE;
2.3.2. New evidence on the zoonotic potential of atypical BSE and atypical scrapie prion strainsNo
Olivier Andreoletti, INRA Research Director, Institut National de la Recherche Agronomique (INRA) – École Nationale Vétérinaire de Toulouse (ENVT), invited speaker, presented the results of two recently published scientific articles of interest, of which he is co-author: ‘Radical Change in Zoonotic Abilities of Atypical BSE Prion Strains as Evidenced by Crossing of Sheep Species Barrier in Transgenic Mice’ (MarinMoreno et al., 2020) and ‘The emergence of classical BSE from atypical/Nor98 scrapie’ (Huor et al., 2019).
In the first experimental study, H-type and L-type BSE were inoculated into transgenic mice expressing all three genotypes of the human PRNP at codon 129 and into adapted into ARQ and VRQ transgenic sheep mice. The results showed the alterations of the capacities to cross the human barrier species (mouse model) and emergence of sporadic CJD agents in Hu PrP expressing mice: type 2 sCJD in homozygous TgVal129 VRQ-passaged L-BSE, and type 1 sCJD in homozygous TgVal 129 and TgMet129 VRQ-passaged H-BSE.
>This information gives insight into the genesis of new prion strains. It also supports the hypothesis that TME can originate from feeding mink protein from cattle afflicted with L-BSE providing evidence to support regulatory decisions for non-food animal species.<
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies
https://www.nature.com/articles/srep11573
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
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
Location: Virus and Prion Research
2020 Annual ReportObjectives
Objective 1: Investigate the mechanisms of protein misfolding in prion disease, including the genetic determinants of misfolding of the prion protein, environmental influences on abnormal prion conversion, and environmental influences on protein misfolding as it relates to prion diseases. Objective 2: Investigate the pathobiology of prion strains in natural hosts, including the influence of prion source genotype on interspecies transmission and the pathobiology of atypical transmissible spongiform encephalopathies (TSEs) and the presence of CWD prion strains in natural hosts by processing field samples through a strain identification program. Subobjective 2.A: Investigate the pathobiology of atypical TSEs. Subobjective 2.B: Investigate the influence of prion source genotype on interspecies transmission. Objective 3: Investigate sampling methodologies for antemortem detection of prion disease, including the utility of blood sampling as a means to assess prion disease status of affected animals and the utility of environmental sampling for monitoring herd prion disease status. Subobjective 3.A: Investigate the utility of blood sampling as a means to assess prion disease status of affected animals. Subobjective 3.B: Investigate the utility of environmental sampling for monitoring herd prion disease status. Objective 4: Determine the association of disease susceptibility or resistance with naturally occurring prion protein genotypes not yet associated with positive cases on infected premises, including genotype associated differences in prion accumulation and excretion, and develop a logic-based decision tree for CWD strain determination. Objective 5: Develop improved live animal test for the detection of CWD-affected cervids, including a sensitive live animal test to detect CWD prions in individual animals, a sensitive live animal screening test for the purpose of determining a herd’s CWD status, and a sensitive deployable CWD test for use by State diagnostic labs.
Objective 1: Investigate the mechanisms of protein misfolding in prion disease, including the genetic determinants of misfolding of the prion protein, environmental influences on abnormal prion conversion, and environmental influences on protein misfolding as it relates to prion diseases. Objective 2: Investigate the pathobiology of prion strains in natural hosts, including the influence of prion source genotype on interspecies transmission and the pathobiology of atypical transmissible spongiform encephalopathies (TSEs) and the presence of CWD prion strains in natural hosts by processing field samples through a strain identification program. Subobjective 2.A: Investigate the pathobiology of atypical TSEs. Subobjective 2.B: Investigate the influence of prion source genotype on interspecies transmission. Objective 3: Investigate sampling methodologies for antemortem detection of prion disease, including the utility of blood sampling as a means to assess prion disease status of affected animals and the utility of environmental sampling for monitoring herd prion disease status. Subobjective 3.A: Investigate the utility of blood sampling as a means to assess prion disease status of affected animals. Subobjective 3.B: Investigate the utility of environmental sampling for monitoring herd prion disease status. Objective 4: Determine the association of disease susceptibility or resistance with naturally occurring prion protein genotypes not yet associated with positive cases on infected premises, including genotype associated differences in prion accumulation and excretion, and develop a logic-based decision tree for CWD strain determination. Objective 5: Develop improved live animal test for the detection of CWD-affected cervids, including a sensitive live animal test to detect CWD prions in individual animals, a sensitive live animal screening test for the purpose of determining a herd’s CWD status, and a sensitive deployable CWD test for use by State diagnostic labs.
Approach
The studies will focus on three animal transmissible spongiform encephalopathy (TSE) agents found in the United States: bovine spongiform encephalopathy (BSE); scrapie of sheep and goats; and chronic wasting disease (CWD) of deer, elk, and moose. The research will address sites of protein folding and misfolding as it relates to prion disease, accumulation of misfolded protein in the host, routes of infection, and ante mortem diagnostics with an emphasis on controlled conditions and natural routes of infection. Techniques used will include spectroscopic monitoring of protein folding/misfolding, clinical exams, histopathology, immunohistochemistry, and biochemical analysis of proteins. The enhanced knowledge gained from this work will help understand the underlying mechanisms of prion disease and mitigate the potential for unrecognized epidemic expansions of these diseases in populations of animals that could either directly or indirectly affect food animals.
The studies will focus on three animal transmissible spongiform encephalopathy (TSE) agents found in the United States: bovine spongiform encephalopathy (BSE); scrapie of sheep and goats; and chronic wasting disease (CWD) of deer, elk, and moose. The research will address sites of protein folding and misfolding as it relates to prion disease, accumulation of misfolded protein in the host, routes of infection, and ante mortem diagnostics with an emphasis on controlled conditions and natural routes of infection. Techniques used will include spectroscopic monitoring of protein folding/misfolding, clinical exams, histopathology, immunohistochemistry, and biochemical analysis of proteins. The enhanced knowledge gained from this work will help understand the underlying mechanisms of prion disease and mitigate the potential for unrecognized epidemic expansions of these diseases in populations of animals that could either directly or indirectly affect food animals.
Progress Report
Five of the seven project plan milestones for FY20 were fully met with the remaining two substantially met. Research efforts directed toward meeting Objective 1 of our project plan originally centered around the production of recombinant prion protein from either bacteria or mammalian tissue culture systems and collection of data on the folding and misfolding of the recombinant prion protein produced. The amount of expressed protein from mammalian expression systems was inherently too low to fully accomplish all aspects of the proposed work. Due to this we have altered our research plan but are still able to accomplish the end goal of understanding the influence of metal ions on prion disease using a mutagenesis based approach altering the metal ion binding sites. Due to the long-term nature of Objective 2, the progress status of the objective has not changed. All studies have been initiated and animals are under observation for the development of clinical signs. The animal studies for this objective are long term and will continue until onset of clinical signs. In vitro studies planned in parallel to the animal's studies have similarly been initiated and are ongoing. Objective 3 of the project plan focuses on the detection of disease associated prion protein in body fluids and feces collected from a time course study of chronic wasting disease inoculated animals. At this time sample collection is complete and preliminary methods have been established. Optimization of those methods is nearing completion and the feasibility of using pooled samples to assess overall herd status is being investigated. Objectives 4 and 5 were recently added to the project and work on both is in the preliminary stages.
Five of the seven project plan milestones for FY20 were fully met with the remaining two substantially met. Research efforts directed toward meeting Objective 1 of our project plan originally centered around the production of recombinant prion protein from either bacteria or mammalian tissue culture systems and collection of data on the folding and misfolding of the recombinant prion protein produced. The amount of expressed protein from mammalian expression systems was inherently too low to fully accomplish all aspects of the proposed work. Due to this we have altered our research plan but are still able to accomplish the end goal of understanding the influence of metal ions on prion disease using a mutagenesis based approach altering the metal ion binding sites. Due to the long-term nature of Objective 2, the progress status of the objective has not changed. All studies have been initiated and animals are under observation for the development of clinical signs. The animal studies for this objective are long term and will continue until onset of clinical signs. In vitro studies planned in parallel to the animal's studies have similarly been initiated and are ongoing. Objective 3 of the project plan focuses on the detection of disease associated prion protein in body fluids and feces collected from a time course study of chronic wasting disease inoculated animals. At this time sample collection is complete and preliminary methods have been established. Optimization of those methods is nearing completion and the feasibility of using pooled samples to assess overall herd status is being investigated. Objectives 4 and 5 were recently added to the project and work on both is in the preliminary stages.
Accomplishments
1. Differing genetic backgrounds of prion disease sources do not affect likelihood of disease progression. Prion diseases are fatal neurodegenerative diseases that affect a wide range of livestock and wildlife. The disease process occurs through the misfolding of a normally occurring protein. A recently developed approach for the detection of this misfolded protein uses a technique referred to as Real-time quaking induced conversion (RT-QulC). RT-QulC amplifies the amount of misfolded protein for detection and has been used to differentiate prion diseases through differences in the rate of misfolding. ARS scientists in Ames, Iowa, completed a study comparing the relative rates of misfolding in RT-QulC from different sources of chronic wasting disease using both human and bank vole prion protein as the substrate for amplification. Regardless of the chronic wasting disease source and genotype, the bank vole substrate was equivalently sensitive indicating the utility of this substrate for the detection of CWD regardless of host or genotype. Similarly, with human prion protein substrate no differences were found indicating that at the level of conversion of the human prion protein to the fibril form conformation all tested CWD isolates are equivalent. From a diagnostic perspective this further justifies the use of bank vole prion protein as a universal substrate and indicates that regardless of genotype of the CWD source the risk to humans is likely the same. Both results provide important information for knowledge based regulatory decisions by state and federal agencies.
1. Differing genetic backgrounds of prion disease sources do not affect likelihood of disease progression. Prion diseases are fatal neurodegenerative diseases that affect a wide range of livestock and wildlife. The disease process occurs through the misfolding of a normally occurring protein. A recently developed approach for the detection of this misfolded protein uses a technique referred to as Real-time quaking induced conversion (RT-QulC). RT-QulC amplifies the amount of misfolded protein for detection and has been used to differentiate prion diseases through differences in the rate of misfolding. ARS scientists in Ames, Iowa, completed a study comparing the relative rates of misfolding in RT-QulC from different sources of chronic wasting disease using both human and bank vole prion protein as the substrate for amplification. Regardless of the chronic wasting disease source and genotype, the bank vole substrate was equivalently sensitive indicating the utility of this substrate for the detection of CWD regardless of host or genotype. Similarly, with human prion protein substrate no differences were found indicating that at the level of conversion of the human prion protein to the fibril form conformation all tested CWD isolates are equivalent. From a diagnostic perspective this further justifies the use of bank vole prion protein as a universal substrate and indicates that regardless of genotype of the CWD source the risk to humans is likely the same. Both results provide important information for knowledge based regulatory decisions by state and federal agencies.
2. Developed an improved enrichment method for amplification-based prion detection. Prion diseases are fatal neurodegenerative diseases that affect a wide range of livestock and wildlife. The disease process occurs through the misfolding of a normally occurring protein. Detection of this misfolded protein is the only known means by which a prion disease can be diagnosed. A recently developed approach for the detection of this misfolded protein uses a technique referred to as Real-time quaking induced conversion (RT-QulC). RT-QulC amplifies the amount of misfolded protein available for detection but can be inhibited by naturally occurring contaminants in the tissue samples used for the technique. ARS scientists in Ames, Iowa, developed a method to clean the samples prior to analysis and demonstrated the sample cleanup technique enhanced the detection and reduced the time required to assess the results providing additional tools for diagnostic laboratories.
3. Improved understanding of cross-species transmission of the prion disease transmissible mink encephalopathy. This work specifically evaluated susceptibility of sheep to bovine adapted transmissible mink encephalopathy (TME) and evaluated pathobiology of disease. Transmissible spongiform encephalopathies (TSEs), or prion diseases, are fatal brain diseases that affect livestock species. Prion diseases have been shown to jump species as exhibited when classical bovine spongiform encephalitis (BSE) infected cattle products were consumed by humans resulting in variant Creutzfeldt-Jakob disease. Another example of cross-species transmission results in a disease of farmed mink known as TME. The present study was designed to determine the effect of cross-species transmission of TSEs in livestock on the ability to infect mice expressing the cattle prion protein. ARS scientists in Ames, Iowa, found that passing cattle adapted TME prions from cattle to sheep changed the ability of the prions to infect mice. These results were compared to atypical BSE (L-BSE type) and Classical BSE (C-BSE type). Depending on the genotype of sheep used, the disease in mice appeared similar to either L-BSE or C-BSE. These results indicate a shift in the disease outcome based on transmission through sheep with different genotypes. This information gives insight into the genesis of new prion strains. It also supports the hypothesis that TME can originate from feeding mink protein from cattle afflicted with L-BSE providing evidence to support regulatory decisions for non-food animal species.
4. Discovery of a novel strain of chronic wasting disease is present in experimentally inoculated LL132 elk. Chronic wasting disease (CWD) is a fatal disease of deer and elk that causes damaging changes in the brain. The infectious agent is an abnormal protein called a prion that has misfolded from its normal state. Whether or not an elk will get CWD is affected by their genetics. This study evaluated transmission of abnormal prion protein from elk of 3 different genotypes that were infected with CWD to transgenic mice expressing the elk prion protein. Previous work by ARS scientists in Ames, Iowa, demonstrated that there are differences in incubation periods, patterns of abnormal prion accumulation in the brain, and fibril stability features in these different genotypes of elk. This study demonstrates that elk donor genotype-associated differences in relative incubation periods, fibril stability, and lesions in the brain were maintained across first and second passages to mice suggesting that they are different CWD strains that may require different approaches for prevention and eradication. This information is useful to wildlife managers and captive wildlife owners that are selectively breeding animals and could impact future regulations for the control of CWD in the U.S.
5. Development of in vitro modelling system for chronic wasting disease. Prion diseases are invariably fatal neurologic diseases for which there is no known prevention or cure. Because of long incubation times and knowledge gaps in how the disease progresses, there is not a well-defined model for testing potential cures or preventative measures. ARS scientists in Ames, Iowa, developed an ultrasensitive in vitro modeling system for chronic wasting disease (CWD) infectivity of samples from deer or elk. In the first step, prion agents are cultured on a brain slice derived from a prion-susceptible mouse. In the second step, an in vitro prion amplification technique (Real-Time Quaking Induced Conversion or RT-QuIC) is used to test for infectivity of the slices. This work demonstrated that the slice cultures are able to accumulate CWD prions that could be detected by RT-QuIC and more traditional laboratory methods, such as mouse bioassay and immunohistochemistry. In addition, three compounds with potential anti-prion properties were screened using slice culture and RT-QuIC indicating that this model may be useful in developing potential treatment schemes for prion disease. Because mechanisms of neurodegeneration in prion disease are similar to other protein misfolding diseases such as Alzheimer’s disease and Parkinson’s disease, use of this model could have a major impact on improving treatments for other neurodegenerative diseases.
Review Publications
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
https://www.nature.com/articles/srep11573
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.
===============
***thus questioning the origin of human sporadic cases***
===============
***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.
==============
https://prion2015.files.wordpress.com/2015/05/prion2015abstracts.pdf
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
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.
===============
***thus questioning the origin of human sporadic cases***
===============
***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.
==============
https://prion2015.files.wordpress.com/2015/05/prion2015abstracts.pdf
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
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
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates. One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias"
Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the scrapie problem urgent if the sheep industry is not to suffer grievously.
snip...
76/10.12/4.6
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC.
Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK
National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
Wednesday, February 16, 2011
IN CONFIDENCE
SCRAPIE TRANSMISSION TO CHIMPANZEES
IN CONFIDENCE
reference...
RB3.20
TRANSMISSION TO CHIMPANZEES
1. Kuru and CJD have been successfully transmitted to chimpanzees but scrapie and TME have not.
2. We cannot say that scrapie will not transmit to chimpanzees. There are several scrapie strains and I am not aware that all have been tried (that would have to be from mouse passaged material). Nor has a wide enough range of field isolates subsequently strain typed in mice been inoculated by the appropriate routes (i/c, ilp and i/v) :
3. I believe the proposed experiment to determine transmissibility, if conducted, would only show the susceptibility or resistance of the chimpanzee to infection/disease by the routes used and the result could not be interpreted for the predictability of the susceptibility for man. Proposals for prolonged oral exposure of chimpanzees to milk from cattle were suggested a long while ago and rejected.
4. In view of Dr Gibbs' probable use of chimpazees Mr Wells' comments (enclosed) are pertinent. I have yet to receive a direct communication from Dr Schellekers but before any collaboration or provision of material we should identify the Gibbs' proposals and objectives.
5. A positive result from a chimpanzee challenged severely would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
6. A negative result would take a lifetime to determine but that would be a shorter period than might be available for human exposure and it would still not answer the question regarding mans' susceptibility. In the meantime no doubt the negativity would be used defensively. It would however be counterproductive if the experiment finally became positive. We may learn more about public reactions following next Monday' s meeting.
R. Bradley
23 September 1990
CVO (+Mr Wells' comments)
Dr T W A Little
Dr B J Shreeve
90/9.23/1.1.
http://web.archive.org/web/20090506041740/http://www.bseinquiry.gov.uk/files/yb/1990/09/23001001.pdf
IN CONFIDENCE CHIMPANZEES
CODE 18-77 Reference RB3.46
Some further information that may assist in decision making has been gained by discussion with Dr Rosalind Ridley.
She says that careful study of Gajdusek's work shows no increased susceptibility of chimpanzees over New World Monkeys such as Squirrel Monkeys. She does not think it would tell you anything about the susceptibility to man. Also Gajdusek did not, she believes, challenge chimpanzees with scrapie as severely as we did pigs and we know little of that source of scrapie. Comparisons would be difficult. She also would not expect the Home Office to sanction such experiments here unless there was a very clear and important objective that would be important for human health protection. She doubted such a case could be made. If this is the case she thought it would be unethical to do an experiment abroad because we could not do it in our own country.
Retrospectively she feels they should have put up more marmosets than they did. They all remain healthy. They would normally regard the transmission as negative if no disease resulted in five years.
We are not being asked for a decision but I think that before we made one we should gain as much knowledge as we can. If we decided to proceed we would have to bear any criticisms for many years if there was an adverse view by scientists ormedia. This should not be undertaken lightly. There is already some adverse comment here, I gather, on the pig experiment though that will subside.
The Gibbs' (as' distinct from Schellekers') study is somewhat different. We are merely supplying material for comparative studies in a laboratory with the greatest experience of human SEs in the world and it has been sanctioned by USDA (though we do not know for certain yet if chimpanzees specifically will be used). This would keep it at a lower profile than if we conducted such an experiment in the UK or Europe.
I consider we must have very powerful and defendable objectives to go beyond Gibbs' proposed experiments and should not initiate others just because an offer has been made.
Scientists have a responsibility to seek other methods of investigative research other than animal experimentation. At present no objective has convinced me we need to do research using Chimpanzees - a species in need of protection. Resisting such proposals would enable us to communicate that information to the scientist and the public should the need arise. A line would have been drawn.
CVO cc Dr T Dr B W A Little Dr B J Shreeve
R Bradley
26 September 1990
90/9.26/3.2
http://web.archive.org/web/20090506041605/http://www.bseinquiry.gov.uk/files/yb/1990/09/26003001.pdf
this is tse prion political theater here, i.e. what i call TSE PRION POKER...tss
3. Prof. A. Robertson gave a brief account of BSE. The US approach was to accord it a very low profile indeed. Dr. A Thiermann showed the picture in the ''Independent'' with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs.
snip...
PAGE 26
Transmission Studies
Mule deer transmissions of CWD were by intracerebral inoculation and compared with natural cases {the following was written but with a single line marked through it ''first passage (by this route)}....TSS
resulted in a more rapidly progressive clinical disease with repeated episodes of synocopy ending in coma. One control animal became affected, it is believed through contamination of inoculum (?saline). Further CWD transmissions were carried out by Dick Marsh into ferret, mink and squirrel monkey. Transmission occurred in ALL of these species with the shortest incubation period in the ferret.
The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite its subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA veiwed it as a wildlife problem and consequently not their province! ...page 26.
snip...see;
IN CONFIDENCE
PERCEPTIONS OF UNCONVENTIONAL SLOW VIRUS DISEASE OF ANIMALS IN THE USA
GAH WELLS
REPORT OF A VISIT TO THE USA
APRIL-MAY 1989
Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.
snip...
The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...
Terry S. Singeltary Sr.
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