Experimental oral transmission of chronic wasting disease to sika deer (Cervus nippon)
Research Paper
Experimental oral transmission of chronic wasting disease to sika deer (Cervus nippon)
Hyun-Joo Sohn ,Gordon Mitchell,Yoon Hee Lee,Hyo Jin Kim,Kyung-Je Park,Antanas Staskevicus, show all
Pages 271-277 | Received 29 Jun 2020, Accepted 23 Nov 2020, Published online: 10 Dec 2020
Download citation https://doi.org/10.1080/19336896.2020.1857038
Abstract
Chronic wasting disease (CWD) affects a broad array of cervid species and continues to be detected in an expanding geographic range. Initially introduced into the Republic of Korea through the importation of CWD-infected elk (Cervus canadensis), additional cases of CWD were subsequently detected in farmed Korean elk and sika deer (Cervus nippon). Wild and farmed sika deer are found in many regions of Asia, North America, and Europe, although natural transmission to this species has not been detected outside of the Republic of Korea. In this study, the oral transmission of CWD to sika deer was investigated using material from CWD-affected elk. Pathological prion (PrPCWD) immunoreactivity was detected in oropharyngeal lymphoid tissues of one sika deer at 3.9 months post-inoculation (mpi) and was more widely distributed in a second sika deer examined at 10.9 mpi. The remaining four sika deer progressed to clinical disease between 21 and 24 mpi. Analysis of PrPCWD tissue distribution in clinical sika deer revealed widespread deposition in central and peripheral nervous systems, lymphoreticular tissues, and the gastrointestinal tract. Prion protein gene (PRNP) sequences of these sika deer were identical and consistent with those reported in natural sika deer populations. These findings demonstrate the efficient oral transmission of CWD from elk to sika deer.
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Introduced into the Republic of Korea through the inadvertent importation of asymptomatic but infected elk [11], CWD was subsequently detected in farmed elk populations in 2001, 2004 and 2005 [12]. Additional cases were later observed in farmed red deer, sika deer, and several cross-bred deer during investigations in 2010 and 2016 [4]. Farmed and feral sika deer exist in other regions of Asia, North America, and Europe [13], although natural CWD transmission to this species has not yet been documented beyond the Republic of Korea. In several regions of the world, the range of feral sika deer overlaps with other cervids, and hybridization with congeneric species such as red deer is known to occur [13,14]. Additionally, sika deer may be farmed to maintain broodstock for game ranches or for the production of venison and antler velvet, and may be cross-bred or housed with CWD-susceptible cervid species in this context.
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Discussion
Oral transmission of CWD from the brain tissues of infected elk to sika deer (Cervus nippon) occurred efficiently in all six sika deer inoculated in this study. PrPCWD was detected in tissues routinely collected for surveillance purposes (retropharyngeal lymph node and tonsil), using commercially available test methods, as early as 3.9 months after inoculation. Four of the six animals developed relatively comparable clinical symptoms and succumbed to disease within a mean period of 22 months. This incubation period is comparable to what has been reported in oral CWD inoculation studies in red deer [19] and elk homozygous for methionine at codon 132 [20], both species which are phylogenetically closely related to sika deer [21]. The progressive accumulation of PrPCWD in lymphoreticular and nervous system tissues was generally consistent with disease progression in other cervids infected naturally or experimentally with CWD [22].
The early accumulation of PrPCWD in oropharyngeal lymphoid tissues typically precedes broader lymphoid tissue involvement as well as the deposition of PrPCWD in central and peripheral nervous systems and other organs [23–25]. Our earliest tissue collection occurred at 3.9 mpi, at which point tonsil and retropharyngeal lymph node contained detectable PrPCWD, and by 10.9 mpi, PrPCWD was present in an array of peripheral lymph nodes and lymphoid follicles of the gastrointestinal tract. Other studies have found initial PrPCWD accumulations are detectable by IHC in oropharyngeal lymphoid tissues within a few weeks following the oral inoculation of mule deer [26] or white-tailed deer [25].
The progression from initial lymphoid deposition to eventual CNS involvement is a consistent feature of CWD pathogenesis in white-tailed deer and mule deer, with surveys detecting a proportion of early cases which are positive in lymph nodes but not the CNS [27–30]. This progression was also observed in our early incubation stage sika deer, but a more variable PrPCWD tissue distribution pattern appears to exist in elk. Surveys of CWD-infected elk populations detect cases which are positive in lymph nodes and not the CNS, but they also find a small percentage of animals to be positive in the obex, without detectable PrPCWD in retropharyngeal lymph nodes or tonsils [31–34] suggesting that limited lymphoid deposition may occur prior to CNS infection in this species. A study of PrPres in lymphoid tissues of CWD-infected deer and elk found comparatively higher levels could be detected in deer tonsil and lymph node samples [35], further supporting species differences in the tissue distribution of PrPCWD. Reasons for these varying tissue accumulation patterns are not clear but may relate to host genetics or conformational differences in the infectious agent. Given the close phylogenetic relationship between sika deer, elk and red deer [21], it seems reasonable to predict that surveys of CWD-exposed sika deer may identify a small proportion of CWD cases which have detectable PrPCWD in obex but not oropharyngeal lymphoid tissues.
In the four sika deer reaching clinical end point in this study, PrPCWD was widely disseminated throughout multiple organ systems. Although immunohistochemistry did not detect PrPCWD in some tissues such as skeletal muscle and skin, we cannot exclude the possibility that infectivity exists in these tissues below the detection levels of the methods used here. Amplification assays such as PMCA and RT-QuIC have the potential to characterize low PrPCWD tissue levels earlier in disease than the methods used in our study [36,37] and further analysis using these assays will refine our understanding of the progression of PrPCWD distribution in sika deer.
The PRNP sequence was identical in all six sika deer in our study and had been previously identified in studies of Asian [15–17] and European sika deer [18]. Many of the alleles present in our sika deer have been associated with CWD susceptibility in other cervid species (95Q, 96G, 132M, 225S) [6]. Sequence variation at codons 100 (S100G) and 226 (Q226E) has been identified in Chinese and Korean sika deer populations [15,17] although the relative significance of these polymorphisms on CWD susceptibility in sika deer remains unknown. Variation at codon 226 (Q226E) is common in red deer [18,38,39], although an oral transmission study found all genotypes (EE, EQ and QQ) were susceptible to CWD [19]. Notwithstanding an effect on CWD susceptibility, Q and E amino acid differences at codon 226 appear to influence CWD strain selection and propagation during disease progression, with potential repercussions on transmissibility within and between animal species [40]. Further study on the influence of codon 226 polymorphisms is relevant given the current presence of codon 226 variability in some sika deer populations, and the potential for increased variability in sika deer following hybridization with red deer.
Studies associating PRNP polymorphisms with resistance to CWD have largely been conducted in CWD-exposed populations of farmed or feral cervids in North America. Reduced CWD susceptibility has been associated with common polymorphisms such as M132L in elk and G96S in deer [6], but rarer polymorphisms may also convey resistance or alter disease progression in some cervid populations [41]. Numerous subspecies of sika deer exist in different regions of the world [13], and hybridization with other cervids has been demonstrated [14], so a more comprehensive assessment of PRNP polymorphisms in sika deer may reveal additional influential variants. The extent to which PRNP polymorphisms in sika deer convey resistance to different CWD isolates from North America, Korea or Scandinavia remains to be elucidated, and it is unknown if sika deer are susceptible to the novel type of CWD recently described in Europe [42].
Widespread detection of PrPCWD by IHC suggests that infectivity is distributed throughout a broad range of tissues in sika deer with clinical CWD, indicating the potential for transmission to other cervid species, and human exposure during the processing and consumption of infected animals. The early presence of PrPCWD in peripheral lymphoid tissues reflects the progressive accumulation pattern observed in other cervids and it seems reasonable to expect infectivity to be shed through similar routes such as feces, urine and saliva. PRNP polymorphisms associated with CWD resistance in other cervids were not present in the sika deer of this study, and the influence of other sika deer PRNP polymorphisms remains to be determined. Farmed and feral sika deer populations are distributed throughout the world and should be considered susceptible to CWD during the application of surveillance and control strategies.
SUNDAY, JULY 14, 2019
Korea Chronic Wasting Disease CWD TSE Prion additional cases were observed in red deer, sika deer, and their crossbred deer in 2010 and 2016, beyond that, anyone's guess
Transmissible Spongiform Encephalopathy TSE Prion End of Year Report
CJD FOUNDATION VIRTUAL CONFERENCE CJD Foundation Research Grant Recipient Reports Panel 2 Nov 3, 2020
zoonotic potential of PMCA-adapted CWD PrP 96SS inoculum
4 different CWD strains, and these 4 strains have different potential to induce any folding of the human prion protein.
***> PIGS, WILD BOAR, CWD <***
***> POPULATIONS OF WILD BOARS IN THE UNITED STATES INCREASING SUPSTANTUALLY AND IN MANY AREAS WE CAN SEE A HIGH DENSITY OF WILD BOARS AND HIGH INCIDENT OF CHRONIC WASTING DISEASE
HYPOTHOSIS AND SPECIFIC AIMS
HYPOTHOSIS
BSE, SCRAPIE, AND CWD, EXPOSED DOMESTIC PIGS ACCUMULATE DIFFERENT QUANTITIES AND STRAINS OF PRIONS IN PERIPHERAL TISSUES, EACH ONE OF THEM WITH PARTICULAR ZOONOTIC POTENTIALS
Final Report – CJD Foundation Grant Program A.
Project Title: Systematic evaluation of the zoonotic potential of different CWD isolates. Principal Investigator: Rodrigo Morales, PhD.
Systematic evaluation of the zoonotic potential of different CWD isolates. Rodrigo Morales, PhD Assistant Professor Protein Misfolding Disorders lab Mitchell Center for Alzheimer’s disease and Related Brain Disorders Department of Neurology University of Texas Health Science Center at Houston Washington DC. July 14th, 2018
Conclusions and Future Directions • We have developed a highly sensitive and specific CWD-PMCA platform to be used as a diagnostic tool. • Current PMCA set up allow us to mimic relevant prion inter-species transmission events. • Polymorphic changes at position 96 of the prion protein apparently alter strain properties and, consequently, the zoonotic potential of CWD isolates. • Inter-species and inter-polymorphic PrPC → PrPSc conversions further increase the spectrum of CWD isolates possibly present in nature. • CWD prions generated in 96SS PrPC substrate apparently have greater inter-species transmission potentials. • Future experiments will explore the zoonotic potential of CWD prions along different adaptation scenarios, including inter-species and inter-polymorphic.
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 - Orise Fellow item Kunkle, Robert item KONDRU, NAVEEN - Iowa State University item MANNE, SIREESHA - Iowa State University item SMITH, JODI - Iowa State University item KANTHASAMY, ANUMANTHA - Iowa State University item WEST GREENLEE, M - Iowa State University 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 month challenge groups). The remaining pigs (>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.
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.
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:
Technical Abstract: We have previously shown that the chronic wasting disease (CWD) agent from white-tailed deer can be transmitted to domestic pigs via intracranial or oral inoculation although with low attack rates and restricted PrPSc accumulation. The objective of this study was to assess the potential for cross-species transmission of pig-passaged CWD using bioassay in transgenic mice. Transgenic mice expressing human (Tg40), bovine (TgBovXV) or porcine (Tg002) PRNP were inoculated intracranially with 1% brain homogenate from a pig that had been intracranially inoculated with a pool of CWD from white-tailed deer. This pig developed neurological clinical signs, was euthanized at 64 months post-inoculation, and PrPSc was detected in the brain. Mice were monitored daily for clinical signs of disease until the end of the study. Mice were considered positive if PrPSc was detected in the brain using an enzyme immunoassay (EIA). In transgenic mice expressing porcine prion protein the average incubation period was 167 days post-inoculation (dpi) and 3/27 mice were EIA positive (attack rate = 11%). All 3 mice were found dead and clinical signs were not noted prior to death. One transgenic mouse expressing bovine prion protein was euthanized due to excessive scratching at 617 dpi and 2 mice culled at the end of the study at 700 dpi were EIA positive resulting in an overall attack rate of 3/16 (19%). None of the transgenic mice expressing human prion protein that died or were euthanized up to 769 dpi were EIA positive and at study end point at 800 dpi 2 mice had positive EIA results (overall attack rate = 2/20 = 10%). The EIA optical density (OD) readings for all positive mice were at the lower end of the reference range (positive mice range, OD = 0.266-0.438; test positive reference range, OD = 0.250-4.000). To the authors’ knowledge, cervid-derived CWD isolates have not been successfully transmitted to transgenic mice expressing human prion protein. 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.
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
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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.
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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).
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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.
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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.
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***> 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.
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 ***
MONDAY, NOVEMBER 23, 2020
***> Chronic Wasting Disease CWD TSE Prion Cervid State by State and Global Update November 2020
MONDAY, NOVEMBER 30, 2020
***> REPORT OF THE MEETING OF THE OIE SCIENTIFIC COMMISSION FOR ANIMAL DISEASES Paris, 9–13 September 2019 BSE, TSE, PRION
see updated concerns with atypical BSE from feed and zoonosis...terry
Monday, November 30, 2020
Tunisia has become the second country after Algeria to detect a case of CPD within a year
TUESDAY, NOVEMBER 17, 2020
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSE) in 2019 First published 17 November 2020
WEDNESDAY, OCTOBER 28, 2020
EFSA Annual report of the Scientific Network on BSE-TSE 2020 Singeltary Submission
WEDNESDAY, OCTOBER 28, 2020
EFSA Scientific Opinion Potential BSE risk posed by the use of ruminant collagen and gelatine in feed for non‐ruminant farmed animals
WEDNESDAY, DECEMBER 2, 2020
EFSA Evaluation of public and animal health risks in case of a delayed post-mortem inspection in ungulates EFSA Panel on Biological Hazards (BIOHAZ) ADOPTED: 21 October 2020
i wonder if a 7 month delay on a suspect BSE case in Texas is too long, on a 48 hour turnaround, asking for a friend???
TUESDAY, DECEMBER 01, 2020
Sporadic Creutzfeldt Jakob Disease sCJD and Human TSE Prion Annual Report December 14, 2020
TSE PRION THE FULL MONTY AKA MAD COW TYPE DISEASE TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY
----Original Message-----
From: Terry Singeltary
To: Tracy.A.Nichols
Sent: Fri, Mar 30, 2018 12:51 pm
Subject: Docket No. APHIS-2018-0011 Chronic Wasting Disease Herd Certification Program Standards Singeltary Submission March 30, 2018
Docket No. APHIS-2018-0011 Chronic Wasting Disease Herd Certification Program Standards Singeltary Submission March 30, 2018
Greetings APHIS, USDA, Dr. Tracy Nichols, et al,
I wish to kindly submit my comments on the Docket No. APHIS-2018-0011 Chronic Wasting Disease Herd Certification Program Standards please. i have submitted online and sent a hard copy to Dr. Nichols via email. i know that my concern may not be the same concern as others, but ramifications from cwd tse prion can be long lasting, and science is still emerging. however, the science today warrants immediate and further actions be taken. my comments, with reference materials, are as follows, and will be formatted in such a way, i will address issues by numbers 1-10, and under each one of my comments by each number, i will reference my comments with science to back up what i am stating/asking...thank you kindly, terry
snip...see full text;
WEDNESDAY, NOVEMBER 4, 2020
CWD TSE PRION, SCRAPIE, BSE, AND PORCINE, PIGS, WILD BOAR, ZOONOTIC ZOONOSIS RISK FACTORS AND POTENTIALS
2.3.2. New evidence on the zoonotic potential of atypical BSE and atypical scrapie prion strains
2.3.2. New evidence on the zoonotic potential of atypical BSE and atypical scrapie prion strains
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.
FRIDAY, OCTOBER 04, 2019
Inactivation of chronic wasting disease prions using sodium hypochlorite
i think some hunters that don't read this carefully are going to think this is a cure all for cwd tse contamination. IT'S NOT!
first off, it would take a strong bleach type sodium hypochlorite, that is NOT your moms bleach she uses in her clothes, and store bought stuff.
Concentrated bleach is an 8.25 percent solution of sodium hypochlorite, up from the “regular bleach” concentration of 5.25 percent.Nov 1, 2013 https://waterandhealth.org/disinfect/high-strength-bleach-2/
second off, the study states plainly;
''We found that a five-minute treatment with a 40% dilution of household bleach was effective at inactivating CWD seeding activity from stainless-steel wires and CWD-infected brain homogenates. However, bleach was not able to inactivate CWD seeding activity from solid tissues in our studies.''
''We initially tested brains from two CWD-infected mice and one uninfected mouse using 40% bleach for 5 minutes. The results from these experiments showed almost no elimination of prion seeding activity (Table 4). We then increased the treatment time to 30 minutes and tested 40% and 100% bleach treatments. Again, the results were disappointing and showed less than a 10-fold decrease in CWD-seeding activity (Table 4). Clearly, bleach is not able to inactivate prions effectively from small brain pieces under the conditions tested here.''
''We found that both the concentration of bleach and the time of treatment are critical for inactivation of CWD prions. A 40% bleach treatment for 5 minutes successfully eliminated detectable prion seeding activity from both CWD-positive brain homogenate and stainless-steel wires bound with CWD. However, even small solid pieces of CWD-infected brain were not successfully decontaminated with the use of bleach.''
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0223659
https://chronic-wasting-disease.blogspot.com/2019/10/inactivation-of-chronic-wasting-disease.html
i think with all the fear from recent studies, and there are many, of potential, or likelihood of zoonosis, if it has not already happened as scjd, i think this study came out to help out on some of that fear, that maybe something will help, but the study plainly states it's for sure not a cure all for exposure and contamination of the cwd tse prion on surface materials. imo...terry
HUNTERS, CWD TSE PRION, THIS SHOULD A WAKE UP CALL TO ALL OF YOU GUTTING AND BONING OUT YOUR KILL IN THE FIELD, AND YOUR TOOLS YOU USE...
* 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]
Wednesday, September 11, 2019
Is the re-use of sterilized implant abutments safe enough? (Implant abutment safety) iatrogenic TSE Prion
172. Establishment of PrPCWD extraction and detection methods in the farm soil
Kyung Je Park, Hoo Chang Park, In Soon Roh, Hyo Jin Kim, Hae-Eun Kang and Hyun Joo Sohn
Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Gimcheon, Gyeongsangbuk-do, Korea
ABSTRACT
Introduction: Transmissible spongiform encephalopathy (TSE) is a fatal neurodegenerative disorder, which is so-called as prion diseases due to the causative agents (PrPSc). TSEs are believed to be due to the template-directed accumulation of disease-associated prion protein, generally designated PrPSc. Chronic wasting disease (CWD) is the prion disease that is known spread horizontally. CWD has confirmed last in Republic of Korea in 2016 since first outbreak of CWD in 2001. The environmental reservoirs mediate the transmission of this disease. The significant levels of infectivity have been detected in the saliva, urine, and faeces of TSE-infected animals. Soil can serve as a stable reservoir for infectious prion proteins. We found that PrPCWD can be extracted and detected in CWD contaminated soil which has kept at room temperature until 4 years after 0.001 ~ 1% CWD exposure and natural CWD-affected farm soil through PBS washing and sPMCAb.
Materials and Methods: Procedure of serial PMCAb. CWD contaminated soil which has kept at room temperature (RT) for 1 ~ 4 year after 0.001%~1% CWD brain homogenates exposure for 4 months collected 0.14 g. The soil was collected by the same method once of year until 4 year after stop CWD exposure. We had conducted the two steps. There are two kinds of 10 times washing step and one amplification step. The washing step was detached PrPSc from contaminated soil by strong vortex with maximum rpm. We harvest supernatant every time by 10 times. As the other washing step, the Washed soil was made by washing 10 times soil using slow rotator and then harvest resuspended PBS for removing large impurity material. Last step was prion amplification step for detection of PrPCWD in soil supernatant and the washed soil by sPMCAb. Normal brain homogenate (NBH) was prepared by homogenization of brains with glass dounce in 9 volumes of cold PBS with TritonX-100, 5 mM EDTA, 150 mM NaCl and 0.05% Digitonin (sigma) plus Complete mini protease inhibitors (Roche) to a final concentration of 5%(w/v) NBHs were centrifuged at 2000 g for 1 min, and supernatant removed and frozen at −70 C for use. CWD consisted of brain from natural case in Korea and was prepared as 10%(w/v) homogenate. Positive sample was diluted to a final dilution 1:1000 in NBH, with serial 3:7 dilutions in NBH. Sonication was performed with a Misonix 4000 sonicator with amplitude set to level 70, generating an average output of 160W with two teflon beads during each cycle. One round consisted of 56 cycles of 30 s of sonication followed 9 min 30 s of 37°C incubation. Western Blotting (WB) for PrPSc detection. The samples (20 µL) after each round of amplification were mixed with proteinase K (2 mg/ml) and incubated 37°C for 1 h. Samples were separated by SDS-PAGE and transferred onto PVDF membrane. After blocking, the membrane was incubated for 1 h with 1st antibody S1 anti rabbit serum (APQA, 1:3000) and developed with enhanced chemiluminescence detection system.
Results: We excluded from first to third supernatant in view of sample contamination. It was confirmed abnormal PrP amplification in all soil supernatants from fourth to tenth. From 0.01% to 1% contaminated washed soils were identified as abnormal prions. 0.001% contaminated washed soil did not show PrP specific band (Fig 1). The soil was collected by the same method once of year until 4 year after stop CWD exposure. After sPMCAb, there were no PrPCWD band in from second to fourth year 0.001% washed soil. but It was confirmed that the abnormal prion was amplified in the washing supernatant which was not amplified in the washed soil. we have decided to use soil supernatant for soil testing (Fig. 2). After third rounds of amplification, PrPSc signals observed in three out of four sites from CWD positive farm playground. No signals were observed in all soil samples from four CWD negative farm (Fig. 3).
Conclusions: Our studies showed that PrPCWD persist in 0.001% CWD contaminated soil for at least 4 year and natural CWD-affected farm soil. When cervid reintroduced into CWD outbreak farm, the strict decontamination procedures of the infectious agent should be performed in the environment of CWD-affected cervid habitat.
===
186. Serial detection of hematogenous prions in CWD-infected deer
Amy V. Nalls, Erin E. McNulty, Nathaniel D. Denkers, Edward A. Hoover and Candace K. Mathiason
Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
CONTACT Amy V. Nalls amy.nalls@colostate.edu
ABSTRACT
Blood contains the infectious agent associated with prion disease affecting several mammalian species, including humans, cervids, sheep, and cattle. It has been confirmed that sufficient prion agent is present in the blood of both symptomatic and asymptomatic carriers to initiate the amyloid templating and accumulation process that results in this fatal neurodegenerative disease. Yet, to date, the ability to detect blood-borne prions by in vitro methods remains difficult.
We have capitalized on blood samples collected from longitudinal chronic wasting disease (CWD) studies in the native white-tailed deer host to examine hematogenous prion load in blood collected minutes, days, weeks and months post exposure. Our work has focused on refinement of the amplification methods RT-QuIC and PMCA. We demonstrate enhanced in vitro detection of amyloid seeding activity (prions) in blood cell fractions harvested from deer orally-exposed to 300 ng CWD positive brain or saliva.
These findings permit assessment of the role hematogenous prions play in the pathogenesis of CWD and provide tools to assess the same for prion diseases of other mammalian species.
Considering the oral secretion of prions, saliva from CWD-infected deer was shown to transmit disease to other susceptible naïve deer when harvested from the animals in both the
and preclinical stages69
of infection, albeit within relatively large volumes of saliva (50 ml). In sheep with preclinical, natural scrapie infections, sPMCA facilitated the detection of PrPSc within buccal swabs throughout most of the incubation period of the disease with an apparent peak in prion secretion around the mid-term of disease progression.70
The amounts of prion present in saliva are likely to be low as indicated by CWD-infected saliva producing prolonged incubation periods and incomplete attack rates within the transgenic mouse bioassay.41
snip...
Indeed, it has also been shown that the scrapie and CWD prions are excreted in urine, feces and saliva and are likely to be excreted from skin. While levels of prion within these excreta/secreta are very low, they are produced throughout long periods of preclinical disease as well as clinical disease. Furthermore, the levels of prion in such materials are likely to be increased by concurrent inflammatory conditions affecting the relevant secretory organ or site. Such dissemination of prion into the environment is very likely to facilitate the repeat exposure of flockmates to low levels of the disease agent, possibly over years.
snip...
Given the results with scrapie-contaminated milk and CWD-contaminated saliva, it seems very likely that these low levels of prion in different secreta/excreta are capable of transmitting disease upon prolonged exposure, either through direct animal-to-animal contact or through environmental reservoirs of infectivity.
the other part, these tissues and things in the body then shed or secrete prions which then are the route to other animals into the environment, so in particular, the things, the secretions that are infectious are salvia, feces, blood and urine. so pretty much anything that comes out of a deer is going to be infectious and potential for transmitting disease.
***>>> 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.
========================
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.
HUNTERS, CWD TSE PRION, THIS SHOULD A WAKE UP CALL TO ALL OF YOU GUTTING AND BONING OUT YOUR KILL IN THE FIELD, AND YOUR TOOLS YOU USE...
* 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]
Wednesday, September 11, 2019
Is the re-use of sterilized implant abutments safe enough? (Implant abutment safety) iatrogenic TSE Prion
SATURDAY, MARCH 16, 2019
Medical Devices Containing Materials Derived from Animal Sources (Except for In Vitro Diagnostic Devices) Guidance for Industry and Food and Drug Administration Staff Document issued on March 15, 2019 Singeltary Submission
THURSDAY, SEPTEMBER 27, 2018
***> Estimating the impact on food and edible materials of changing scrapie control measures: The scrapie control model
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]
2018 - 2019
***> This is very likely to have parallels with control efforts for CWD in cervids.
Rapid recontamination of a farm building occurs after attempted prion removal
Kevin Christopher Gough, BSc (Hons), PhD1, Claire Alison Baker, BSc (Hons)2, Steve Hawkins, MIBiol3, Hugh Simmons, BVSc, MRCVS, MBA, MA3, Timm Konold, DrMedVet, PhD, MRCVS3 and Ben Charles Maddison, BSc (Hons), PhD2
Abstract
The transmissible spongiform encephalopathy scrapie of sheep/goats and chronic wasting disease of cervids are associated with environmental reservoirs of infectivity.
Preventing environmental prions acting as a source of infectivity to healthy animals is of major concern to farms that have had outbreaks of scrapie and also to the health management of wild and farmed cervids.
Here, an efficient scrapie decontamination protocol was applied to a farm with high levels of environmental contamination with the scrapie agent.
Post-decontamination, no prion material was detected within samples taken from the farm buildings as determined using a sensitive in vitro replication assay (sPMCA).
A bioassay consisting of 25 newborn lambs of highly susceptible prion protein genotype VRQ/VRQ introduced into this decontaminated barn was carried out in addition to sampling and analysis of dust samples that were collected during the bioassay.
Twenty-four of the animals examined by immunohistochemical analysis of lymphatic tissues were scrapie-positive during the bioassay, samples of dust collected within the barn were positive by month 3.
The data illustrates the difficulty in decontaminating farm buildings from scrapie, and demonstrates the likely contribution of farm dust to the recontamination of these environments to levels that are capable of causing disease.
snip...
As in the authors' previous study,12 the decontamination of this sheep barn was not effective at removing scrapie infectivity, and despite the extra measures brought into this study (more effective chemical treatment and removal of sources of dust) the overall rates of disease transmission mirror previous results on this farm. With such apparently effective decontamination (assuming that at least some sPMCA seeding ability is coincident with infectivity), how was infectivity able to persist within the environment and where does infectivity reside? Dust samples were collected in both the bioassay barn and also a barn subject to the same decontamination regime within the same farm (but remaining unoccupied). Within both of these barns dust had accumulated for three months that was able to seed sPMCA, indicating the accumulation of scrapie-containing material that was independent of the presence of sheep that may have been incubating and possibly shedding low amounts of infectivity.
This study clearly demonstrates the difficulty in removing scrapie infectivity from the farm environment. Practical and effective prion decontamination methods are still urgently required for decontamination of scrapie infectivity from farms that have had cases of scrapie and this is particularly relevant for scrapiepositive goatherds, which currently have limited genetic resistance to scrapie within commercial breeds.24 This is very likely to have parallels with control efforts for CWD in cervids.
Acknowledgements The authors thank the APHA farm staff, Tony Duarte, Olly Roberts and Margaret Newlands for preparation of the sheep pens and animal husbandry during the study. The authors also thank the APHA pathology team for RAMALT and postmortem examination.
Funding This study was funded by DEFRA within project SE1865.
Competing interests None declared.
Saturday, January 5, 2019
Rapid recontamination of a farm building occurs after attempted prion removal
THURSDAY, FEBRUARY 28, 2019
BSE infectivity survives burial for five years with only limited spread
***> CONGRESSIONAL ABSTRACTS PRION CONFERENCE 2018
P69 Experimental transmission of CWD from white-tailed deer to co-housed reindeer
Mitchell G (1), Walther I (1), Staskevicius A (1), Soutyrine A (1), Balachandran A (1)
(1) National & OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada.
Chronic wasting disease (CWD) continues to be detected in wild and farmed cervid populations of North America, affecting predominantly white-tailed deer, mule deer and elk. Extensive herds of wild caribou exist in northern regions of Canada, although surveillance has not detected the presence of CWD in this population. Oral experimental transmission has demonstrated that reindeer, a species closely related to caribou, are susceptible to CWD. Recently, CWD was detected for the first time in Europe, in wild Norwegian reindeer, advancing the possibility that caribou in North America could also become infected. Given the potential overlap in habitat between wild CWD-infected cervids and wild caribou herds in Canada, we sought to investigate the horizontal transmissibility of CWD from white-tailed deer to reindeer.
Two white-tailed deer were orally inoculated with a brain homogenate prepared from a farmed Canadian white-tailed deer previously diagnosed with CWD. Two reindeer, with no history of exposure to CWD, were housed in the same enclosure as the white-tailed deer, 3.5 months after the deer were orally inoculated. The white-tailed deer developed clinical signs consistent with CWD beginning at 15.2 and 21 months post-inoculation (mpi), and were euthanized at 18.7 and 23.1 mpi, respectively. Confirmatory testing by immunohistochemistry (IHC) and western blot demonstrated widespread aggregates of pathological prion protein (PrPCWD) in the central nervous system and lymphoid tissues of both inoculated white-tailed deer. Both reindeer were subjected to recto-anal mucosal associated lymphoid tissue (RAMALT) biopsy at 20 months post-exposure (mpe) to the white-tailed deer. The biopsy from one reindeer contained PrPCWD confirmed by IHC. This reindeer displayed only subtle clinical evidence of disease prior to a rapid decline in condition requiring euthanasia at 22.5 mpe. Analysis of tissues from this reindeer by IHC revealed widespread PrPCWD deposition, predominantly in central nervous system and lymphoreticular tissues. Western blot molecular profiles were similar between both orally inoculated white-tailed deer and the CWD positive reindeer. Despite sharing the same enclosure, the other reindeer was RAMALT negative at 20 mpe, and PrPCWD was not detected in brainstem and lymphoid tissues following necropsy at 35 mpe. Sequencing of the prion protein gene from both reindeer revealed differences at several codons, which may have influenced susceptibility to infection.
Natural transmission of CWD occurs relatively efficiently amongst cervids, supporting the expanding geographic distribution of disease and the potential for transmission to previously naive populations. The efficient horizontal transmission of CWD from white-tailed deer to reindeer observed here highlights the potential for reindeer to become infected if exposed to other cervids or environments infected with CWD.
***> Infectious agent of sheep scrapie may persist in the environment for at least 16 years
***> Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded.
Gudmundur Georgsson,1 Sigurdur Sigurdarson2 and Paul Brown3
Correspondence
Gudmundur Georgsson ggeorgs@hi.is
1 Institute for Experimental Pathology, University of Iceland, Keldur v/vesturlandsveg, IS-112 Reykjavı´k, Iceland
2 Laboratory of the Chief Veterinary Officer, Keldur, Iceland
3 Bethesda, Maryland, USA
Received 7 March 2006 Accepted 6 August 2006
In 1978, a rigorous programme was implemented to stop the spread of, and subsequently eradicate, sheep scrapie in Iceland. Affected flocks were culled, premises were disinfected and, after 2–3 years, restocked with lambs from scrapie-free areas. Between 1978 and 2004, scrapie recurred on 33 farms. Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded. Of special interest was one farm with a small, completely self-contained flock where scrapie recurred 18 years after culling, 2 years after some lambs had been housed in an old sheephouse that had never been disinfected. Epidemiological investigation established with near certitude that the disease had not been introduced from the outside and it is concluded that the agent may have persisted in the old sheep-house for at least 16 years.
TITLE: PATHOLOGICAL FEATURES OF CHRONIC WASTING DISEASE IN REINDEER AND DEMONSTRATION OF HORIZONTAL TRANSMISSION
*** DECEMBER 2016 CDC EMERGING INFECTIOUS DISEASE JOURNAL CWD HORIZONTAL TRANSMISSION
SEE;
Back around 2000, 2001, or so, I was corresponding with officials abroad during the bse inquiry, passing info back and forth, and some officials from here inside USDA aphis FSIS et al. In fact helped me get into the USA 50 state emergency BSE conference call way back. That one was a doozy. But I always remember what “deep throat” I never knew who they were, but I never forgot;
Some unofficial information from a source on the inside looking out -
Confidential!!!!
As early as 1992-3 there had been long studies conducted on small pastures containing scrapie infected sheep at the sheep research station associated with the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are documented...I don't know. But personal recounts both heard and recorded in a daily journal indicate that leaving the pastures free and replacing the topsoil completely at least 2 feet of thickness each year for SEVEN years....and then when very clean (proven scrapie free) sheep were placed on these small pastures.... the new sheep also broke out with scrapie and passed it to offspring. I am not sure that TSE contaminated ground could ever be free of the agent!! A very frightening revelation!!!
---end personal email---end...tss
Infectivity surviving ashing to 600*C is (in my opinion) degradable but infective. based on Bown & Gajdusek, (1991), landfill and burial may be assumed to have a reduction factor of 98% (i.e. a factor of 50) over 3 years. CJD-infected brain-tissue remained infectious after storing at room-temperature for 22 months (Tateishi et al, 1988). Scrapie agent is known to remain viable after at least 30 months of desiccation (Wilson et al, 1950). and pastures that had been grazed by scrapie-infected sheep still appeared to be contaminated with scrapie agent three years after they were last occupied by sheep (Palsson, 1979).
Dr. Paul Brown Scrapie Soil Test BSE Inquiry Document
THURSDAY, FEBRUARY 28, 2019
BSE infectivity survives burial for five years with only limited spread
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.
=========================
***>>> 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.
========================
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.
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production
Detection of protease-resistant cervid prion protein in water from a CWD-endemic area
A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing
Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals
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 ***
WEDNESDAY, MARCH 13, 2019
CWD, TSE, PRION, MATERNAL mother to offspring, testes, epididymis, seminal fluid, and blood
Subject: Prion 2019 Conference
See full Prion 2019 Conference Abstracts
see scientific program and follow the cwd studies here;
Thursday, May 23, 2019
Prion 2019 Emerging Concepts CWD, BSE, SCRAPIE, CJD, SCIENTIFIC PROGRAM Schedule and Abstracts
THURSDAY, DECEMBER 19, 2019
TSE surveillance statistics exotic species and domestic cats Update December 2019
WEDNESDAY, NOVEMBER 4, 2020
CWD TSE PRION, SCRAPIE, BSE, AND PORCINE, PIGS, WILD BOAR, ZOONOTIC ZOONOSIS RISK FACTORS AND POTENTIALS
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...
MONDAY, NOVEMBER 23, 2020
***> Chronic Wasting Disease CWD TSE Prion Cervid State by State and Global Update November 2020
MONDAY, NOVEMBER 30, 2020
***> REPORT OF THE MEETING OF THE OIE SCIENTIFIC COMMISSION FOR ANIMAL DISEASES Paris, 9–13 September 2019 BSE, TSE, PRION
see updated concerns with atypical BSE from feed and zoonosis...terry
Monday, November 30, 2020
Tunisia has become the second country after Algeria to detect a case of CPD within a year
TUESDAY, NOVEMBER 17, 2020
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSE) in 2019 First published 17 November 2020
WEDNESDAY, OCTOBER 28, 2020
EFSA Annual report of the Scientific Network on BSE-TSE 2020 Singeltary Submission
WEDNESDAY, OCTOBER 28, 2020
EFSA Scientific Opinion Potential BSE risk posed by the use of ruminant collagen and gelatine in feed for non‐ruminant farmed animals
WEDNESDAY, DECEMBER 2, 2020
EFSA Evaluation of public and animal health risks in case of a delayed post-mortem inspection in ungulates EFSA Panel on Biological Hazards (BIOHAZ) ADOPTED: 21 October 2020
i wonder if a 7 month delay on a suspect BSE case in Texas is too long, on a 48 hour turnaround, asking for a friend???
TUESDAY, DECEMBER 01, 2020
Sporadic Creutzfeldt Jakob Disease sCJD and Human TSE Prion Annual Report December 14, 2020
23 years today, RIP MOM DOD 12/14/97 confirmed hvCJD, just made a promise to mom, never forget, and never let them forget...
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
12:13 PM
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