Saturday, January 5, 2019

Rapid recontamination of a farm building occurs after attempted prion removal

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

Author affiliations

School of Veterinary Medicine and Science, The University of Nottingham, Loughborough, UK ADAS, School of Veterinary Medicine and Science, The University of Nottingham, Loughborough, UK Animal Sciences Unit, Pathology Department, Animal & Plant Health Agency Weybridge, New Haw, Addlestone, Surrey, UK E-mail for correspondence; ben.maddison@adas.co.uk

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...

snip...

PrPC is ubiquitous in its distribution in vivo2 and with both scrapie and CWD the in vivo dissemination of infectivity is also widespread with PrPSc usually accumulating within peripheral lymphatic tissues before the CNS.3 4 With scrapie, PrPSc can be secreted/ excreted via a multiplicity of routes including saliva,5 6 milk,7 faeces,8 skin9 and urine.10 The accumulation of this material within the environment (particularly the built farm environment),11 12 creates levels of infectivity that can be transmitted to naïve animals. These reservoirs of infectivity can remain infectious for prolonged periods of time, in one such recorded incident at least 16 years.13 The advent of high sensitivity prion replication assays such as protein misfolding cyclic amplification (PMCA) with application to sheep/goat scrapie14 15 has allowed the monitoring of prions within environments.11

Attempts to decontaminate pens on a scrapie-affected farm and measuring efficacy using a sheep bioassay were previously reported.12 It was concluded that the failure of effective decontamination within that study was likely to have been due to the incomplete farm decontamination and the presence of dust containing infectious prions that recontaminated the pen surfaces. The serial protein misfolding cyclic amplification (sPMCA) technique was recently used to confirm the presence of prions within extracts prepared from dust samples that had settled on sterile surfaces.16 Given the presence of mobile infectious prions within dust, it was proposed that for effective scrapie decontamination emphasis should be given to the removal of all sources of dust within the decontamination strategy for a farm. More recently, the sPMCA technique has been used by the authors' laboratory to look at effective methods of decontaminating prions bound to concrete surfaces within the laboratory setting.17 This study demonstrated that current methodology based on a one-hour exposure to 20000 ppm free chlorine was likely to be ineffective at removing surface-bound scrapie prion. However, there was an enhanced effectiveness of this chemical decontamination when using multiple applications over four hours. Here, a study is described where a scrapie-affected farm was decontaminated using four applications of 20000 ppm free chlorine to livestock barns and concreted areas. The decontamination also included a high-level clean of the buildings that had housed sheep to remove all traces of dust as far as practicable before the chemical decontamination procedure. Following these treatments the surfaces within the barn were demonstrably free from prion using a sensitive sPMCA assay. The presence of any residual infectivity was then evaluated by sheep bioassay and dust samples collected during the bioassay were assayed for prion seeding activity by sPMCA.

snip...

Discussion

The authors' previous work on this farm indicated that dust harbours low levels of mobile scrapie prions that can accumulate on surfaces16 and this is likely to perpetuate transmission of scrapie within such a farm environment.12 In addition, previous in vitro modelling of scrapie prions bound to a concrete ‘fomite’ demonstrated that prion seeding activity could be inactivated by four applications of 20,000 ppm free chlorine as measured by a sPMCA assay. This previous modelling demonstrated that residual contamination of the swab extract with hypochlorite at levels which would inhibit the sPMCA are unlikely, and the authors consider these results as reduction in seeding titre.17 Here, this same decontamination methodology was tested within a farm-scale study which also included steps to remove dust within the barns. This study demonstrated that this thorough decontamination method applied to a farm with a high incidence of naturally acquired scrapie was sufficient to remove scrapie prions on surfaces to levels that were undetectable by sPMCA, one of the most sensitive biochemical assays for prions. The authors' sPMCA assay has an limit of detection of around 1–10pg scrapie-infected sheep brain per sPMCA reaction. The authors assume that the samples negative by sPMCA had less than this amount (of brain equivalent) within the extracts that were prepared. This treatment together with measures designed to minimise the amount of dust retained within the buildings (vacuuming all surfaces, pressure washing and then hypochlorite treatment) was expected to have removed all infectivity from the buildings and the concrete areas surrounding them, and it was anticipated that the sheep bioassay would confirm absence of infective prion.

However, the introduction into this decontaminated barn of 25 VRQ/VRQ sheep (a genotype highly susceptible to classical scrapie) demonstrated that all animals, with the exception of 1 lamb that died at 122 dpe, had detectable PrPSc in lymphoid tissue, indicating infection with the scrapie agent. This included 14 animals (54 per cent) that were PrPSc-positive on the first RAMALT analysis at 372 dpe or 419 dpe. Although infected sheep were removed based on a positive RAMALT result, it is possible that lateral transmission or subsequent contamination of the environment from infected sheep had contributed to the rapid spread of scrapie in nearly all sheep. It has been shown previously that objects in contact with scrapie-infected sheep, such as water troughs and fence posts, can act as a reservoir for infection.23 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. 


The effectiveness of on-farm decontamination methods for scrapie - SE1865

Description

Scrapie infectivity persists on farms where infected animals have been removed1. Recently we have demonstrated that it is possible to detect environmental scrapie contamination biochemically using serial Protein Misfolding Cyclic Amplification (sPMCA)2, allowing the monitoring of scrapie infectivity on farm premises. Ongoing Defra study SE1863 has compared pen decontamination regimes on a scrapie-infected farm by both sheep bioassay and sPMCA. For bioassay, scrapie-free genetically susceptible lambs were introduced into pens decontaminated using distinct methodologies, all pens contained scrapie-positive lambs within 1 year. Remarkably this included lambs housed within a pen which had been jet washed/chloros treated, followed by regalvanisation/ replacement of all metalwork and painting of all other surfaces.

We have recently demonstrated using sPMCA, that material collected on swabs from vertical surfaces at heights inaccessible to sheep within a barn on the same scrapie affected farm contained scrapie prions (unpublished observations). We hypothesise that scrapie prions are most likely to have been deposited in these areas by bioaerosol movement. We propose that this bioaerosol movement contributes to scrapie transmission within the barn, and could account for the sheep that became positive within the pen containing re-galvanised/new metalwork and repainted surfaces (project SE1863). It is proposed that a thorough decontamination that would minimise prion-contaminated dust, both within the building and its immediate vicinity, is likely to increase the effectiveness of current methods for decontaminating farm buildings following outbreaks of scrapie. The proposed study builds on our previous data and will thoroughly investigate the potential for farm building scrapie-contamination via the bioaerosol route, a previously unrecognised route for dissemination of scrapie infectivity. This route could lead to the direct infection of healthy animals and/or indirect transmission of disease via contamination of surfaces within animal pens. The proposed study would analyse material collected using air samplers set up within “scrapie-infected” barns and their immediate vicinity, to confirm that prion containing material can be airborne within a scrapie infected farm environment. The study would incorporate a biochemical assessment of different surface decontamination methods, in order to demonstrate the best methodology and then the analysis of air and surface samples after a complete building decontamination to remove sources of dust and surface bound prions from both the building and its immediate vicinity. Analysis of such surface and air samples collected before and after treatment would measure the reduction in levels of infectivity. It is envisaged that the biochemical demonstration of airborne prions and the effective reduction in such prion dissemination would lead to a sheep bioassay experiment that would be conducted after a full farm decontamination. This would fully assess the effectiveness of an optimised scrapie decontamination strategy.

This study will contribute directly to Defra policy on best practice for on-farm decontamination after outbreaks of scrapie; a situation particularly relevant to decontamination after scrapie cases on goat farms where no genetic resistance to scrapie has currently been identified, and where complete decontamination is essential in order to stop recurrence of scrapie after restocking.

Objective

Phase 1

• Determine the presence and relative levels of airborne prions on a scrapie infected farm.

• Evaluate different pen surface decontamination procedures.

Phase 2

• Determine the presence of any airborne prions in a barn after a full decontamination.

Phase 3

• Further assess the efficacy of the decontamination procedure investigated in phase 2 by sheep bioassay.

Time-Scale and Cost

From: 2012 

To: 2016 

Cost: £326,784

Contractor / Funded Organisations

A D A S UK Ltd (ADAS)

Keywords Animals Fields of Study Animal Health


The Effectiveness of on-Farm Decontamination Methods for Scrapie

Institutions ADAS

Start date 2012

End date 2016

Objective Phase 1

Determine the presence and relative levels of airborne prions on a scrapie infected farm. Evaluate different pen surface decontamination procedures.

Phase 2

Determine the presence of any airborne prions in a barn after a full decontamination.

Phase 3

Further assess the efficacy of the decontamination procedure investigated in phase 2 by sheep bioassay.

More information

Scrapie infectivity persists on farms where infected animals have been removed1. Recently we have demonstrated that it is possible to detect environmental scrapie contamination biochemically using serial Protein Misfolding Cyclic Amplification (sPMCA)2, allowing the monitoring of scrapie infectivity on farm premises. Ongoing Defra study SE1863 has compared pen decontamination regimes on a scrapie-infected farm by both sheep bioassay and sPMCA. For bioassay, scrapie-free genetically susceptible lambs were introduced into pens decontaminated using distinct methodologies, all pens contained scrapie-positive lambs within 1 year. Remarkably this included lambs housed within a pen which had been jet washed/chloros treated, followed by regalvanisation/replacement of all metalwork and painting of all other surfaces.

We have recently demonstrated using sPMCA, that material collected on swabs from vertical surfaces at heights inaccessible to sheep within a barn on the same scrapie affected farm contained scrapie prions (unpublished observations). We hypothesise that scrapie prions are most likely to have been deposited in these areas by bioaerosol movement. We propose that this bioaerosol movement contributes to scrapie transmission within the barn, and could account for the sheep that became positive within the pen containing re-galvanised/new metalwork and repainted surfaces (project SE1863). It is proposed that a thorough decontamination that would minimise prion-contaminated dust, both within the building and its immediate vicinity, is likely to increase the effectiveness of current methods for decontaminating farm buildings following outbreaks of scrapie. The proposed study builds on our previous data and will thoroughly investigate the potential for farm building scrapie contamination via the bioaerosol route, a previously unrecognised route for dissemination of scrapie infectivity. This route could lead to the direct infection of healthy animals and/or indirect transmission of disease via contamination of surfaces within animal pens. The proposed study would analyse material collected using air samplers set up within “scrapie-infected” barns and their immediate vicinity, to confirm that prion containing material can be airborne within a scrapie infected farm environment. The study would incorporate a biochemical assessment of different surface decontamination methods, in order to demonstrate the best methodology and then the analysis of air and surface samples after a complete building decontamination to remove sources of dust and surface bound prions from both the building and its immediate vicinity. Analysis of such surface and air samples collected before and after treatment would measure the reduction in levels of infectivity. It is envisaged that the biochemical demonstration of airborne prions and the effective reduction in such prion dissemination would lead to a sheep bioassay experiment that would be conducted after a full farm decontamination. This would fully assess the effectiveness of an optimised scrapie decontamination strategy.

This study will contribute directly to Defra policy on best practice for on-farm decontamination after outbreaks of scrapie; a situation particularly relevant to decontamination after scrapie cases on goat farms where no genetic resistance to scrapie has currently been identified, and where complete decontamination is essential in order to stop recurrence of scrapie after restocking.

Funding Source

Department for Environment, Food and Rural Affairs

Project source

View this project

Project number

SE1865

Categories

Foodborne Disease

Policy and Planning 


Circulation of prions within dust on a scrapie affected farm

Kevin C Gough1 , Claire A Baker2 , Hugh A Simmons3 , Steve A Hawkins3 and Ben C Maddison2*

Abstract

Prion diseases are fatal neurological disorders that affect humans and animals. Scrapie of sheep/goats and Chronic Wasting Disease (CWD) of deer/elk are contagious prion diseases where environmental reservoirs have a direct link to the transmission of disease. Using protein misfolding cyclic amplification we demonstrate that scrapie PrPSc can be detected within circulating dusts that are present on a farm that is naturally contaminated with sheep scrapie. The presence of infectious scrapie within airborne dusts may represent a possible route of infection and illustrates the difficulties that may be associated with the effective decontamination of such scrapie affected premises.

snip... 

Discussion We present biochemical data illustrating the airborne movement of scrapie containing material within a contaminated farm environment. We were able to detect scrapie PrPSc within extracts from dusts collected over a 70 day period, in the absence of any sheep activity. We were also able to detect scrapie PrPSc within dusts collected within pasture at 30 m but not at 60 m distance away from the scrapie contaminated buildings, suggesting that the chance of contamination of pasture by scrapie contaminated dusts decreases with distance from contaminated farm buildings. PrPSc amplification by sPMCA has been shown to correlate with infectivity and amplified products have been shown to be infectious [14,15]. These experiments illustrate the potential for low dose scrapie infectivity to be present within such samples. We estimate low ng levels of scrapie positive brain equivalent were deposited per m2 over 70 days, in a barn previously occupied by sheep affected with scrapie. This movement of dusts and the accumulation of low levels of scrapie infectivity within this environment may in part explain previous observations where despite stringent pen decontamination regimens healthy lambs still became scrapie infected after apparent exposure from their environment alone [16]. The presence of sPMCA seeding activity and by inference, infectious prions within dusts, and their potential for airborne dissemination is highly novel and may have implications for the spread of scrapie within infected premises. The low level circulation and accumulation of scrapie prion containing dust material within the farm environment will likely impede the efficient decontamination of such scrapie contaminated buildings unless all possible reservoirs of dust are removed. Scrapie containing dusts could possibly infect animals during feeding and drinking, and respiratory and conjunctival routes may also be involved. It has been demonstrated that scrapie can be efficiently transmitted via the nasal route in sheep [17], as is also the case for CWD in both murine models and in white tailed deer [18-20].

The sources of dust borne prions are unknown but it seems reasonable to assume that faecal, urine, skin, parturient material and saliva-derived prions may contribute to this mobile environmental reservoir of infectivity. This work highlights a possible transmission route for scrapie within the farm environment, and this is likely to be paralleled in CWD which shows strong similarities with scrapie in terms of prion dissemination and disease transmission. The data indicate that the presence of scrapie prions in dust is likely to make the control of these diseases a considerable challenge.


***> NORWAY CWD UPDATE December 2018


Report from the Norwegian Scientific Committee for Food and Environment (VKM) 2018: 16

Factors that can contribute to spread of CWD – an update on the situation in Nordfjella, Norway

Opinion of Panel on biological hazards of the Norwegian Scientific Committee for Food and Environment

13.12.2018

ISBN: 978-82-8259-316-8

ISSN: 2535-4019

Norwegian Scientific Committee for Food and Environment (VKM)

Po 222 Skøyen

0213 Oslo

Norway

FRIDAY, DECEMBER 14, 2018 

Norway, Nordfjella VKM 2018 16 Factors that can contribute to spread of CWD TSE Prion UPDATE December 14, 2018




Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES Location: Virus and Prion Research

Title: Scrapie transmits to white-tailed deer by the oral route and has a molecular profile similar to chronic wasting disease

Author 

 item Greenlee, Justin item Moore, S - Orise Fellow item Smith, Jodi - Iowa State University item Kunkle, Robert item West Greenlee, M - Iowa State University Submitted to: American College of Veterinary Pathologists Meeting Publication Type: Abstract Only Publication Acceptance Date: 8/12/2015 Publication Date: N/A Citation: N/A

Interpretive Summary:

Technical Abstract: The purpose of this work was to determine susceptibility of white-tailed deer (WTD) to the agent of sheep scrapie and to compare the resultant PrPSc to that of the original inoculum and chronic wasting disease (CWD). We inoculated WTD by a natural route of exposure (concurrent oral and intranasal (IN); n=5) with a US scrapie isolate. All scrapie-inoculated deer had evidence of PrPSc accumulation. PrPSc was detected in lymphoid tissues at preclinical time points, and deer necropsied after 28 months post-inoculation had clinical signs, spongiform encephalopathy, and widespread distribution of PrPSc in neural and lymphoid tissues. Western blotting (WB) revealed PrPSc with 2 distinct molecular profiles. WB on cerebral cortex had a profile similar to the original scrapie inoculum, whereas WB of brainstem, cerebellum, or lymph nodes revealed PrPSc with a higher profile resembling CWD. Homogenates with the 2 distinct profiles from WTD with clinical scrapie were further passaged to mice expressing cervid prion protein and intranasally to sheep and WTD. In cervidized mice, the two inocula have distinct incubation times. Sheep inoculated intranasally with WTD derived scrapie developed disease, but only after inoculation with the inoculum that had a scrapie-like profile. The WTD study is ongoing, but deer in both inoculation groups are positive for PrPSc by rectal mucosal biopsy. In summary, this work demonstrates that WTD are susceptible to the agent of scrapie, two distinct molecular profiles of PrPSc are present in the tissues of affected deer, and inoculum of either profile readily passes to deer.



P144 Environmental Contamination Assessment of CWD Shed in Excreta by RT-QuIC

Dr. Davin Henderson1, Ms. Joanne Tennant1, Dr. Nicholas Haley2, Dr. Nathaniel Denkers1, Dr. Candace Mathiason1, Dr. Edward Hoover1

1Prion Research Center. Department of Microbiology, Immunology and Pathology. Colorado State University, Fort Collins, United States, 2Midwestern State University, Glendale , United States Chronic wasting disease affects free-ranging or captive populations of deer, elk and moose in the United States, Canada, Korea, and most recently Norwegian caribou and moose. CWD is unique in its ability to spread in wild populations, which likely occurs through environmental dissemination or direct contact with prions shed into bodily fluids or excreta. We have made progress to rapidly and cost-effectively detect CWD in urine and feces, which contribute substantially to environmental contamination.

Aims: 1) Using real-time quaking induced conversion (RT-QuIC) we will estimate environmental contamination via urine and feces by CWD positive animals throughout the disease course. 2) We will apply RT-QuIC to estimate CWD incidence in populations without animal capture and assess the persistence of prion seeding activity in feces under environmental conditions in the native range of cervid species.

Methods: CWD prions in fecal and urine samples will be concentrated via iron oxide mediated extraction (IOME) and assayed by RT-QuIC using temperature adjustment modifications to select increase to preserve sensitivity while minimizing specificity.

Results: We assayed longitudinal cohorts of whitetailed deer for prion shedding in feces and urine during the CWD disease course and determined shedding kinetics and consistency. We applied a quantitative approach to these data using a reference brain sample to determine the levels of CWD prions shed in feces and urine during the disease course.

Conclusions: In deer experimentally inoculated with CWD approximately 100 (Tg5037) cervid PrP mouse LD50 doses are shed in urine and ~90 (TG5037) mouse LD50 doses are shed in feces per day. The relationship between cerPrP transgenic mouse and cerivd LD50 doses remains to be determined. In the future, we will apply RT-QuIC detection of CWD in feces to estimate CWD incidence in populations without animal capture and to determine how long prion seeding activity remains active in fecal samples under potentially harsh environment conditions that exist in the native range of cervid species.

see much more;

TUESDAY, JULY 04, 2017

PRION 2017 CONFERENCE ABSTRACTS ON CHRONIC WASTING DISEASE CWD TSE PRION


tse prion soil 





SUNDAY, DECEMBER 11, 2016

Clay Components in Soil Dictate Environmental Stability and Bioavailability of Cervid Prions in Mice


Saturday, May 28, 2016

*** Infection and detection of PrPCWD in soil from CWD infected farm in Korea Prion 2016 Tokyo ***


THURSDAY, FEBRUARY 17, 2011

Environmental Sources of Scrapie Prions

Journal of Virology, November 2010, p. 11560-11562, Vol. 84, No. 21 


Tuesday, June 16, 2009 

Infectious Prions in Pre-Clinical Deer and Transmission of Chronic Wasting Disease Solely by Environmental Exposure 


Sunday, December 06, 2009

Detection of Sub-Clinical CWD Infection in Conventional Test-Negative Deer Long after Oral Exposure to Urine and Feces from CWD+ Deer


Observations of deer and elk in captivity indicate that CWD is contagious though the

exact mechanism(s) of transmission are not yet known. Based on pathogenesis of the disease

it is plausible that the CWD agent exits the body in saliva and feces. The contribution of

82

environmental contamination to the epidemiology of CWD is not specifically known but

observations of cohorts of elk and deer in captivity strongly suggest it is important in areas of

high CWD prevalence and high densities of susceptible species. This is an area of

considerable ongoing research.


CHRONIC WASTING DISEASE

Review of research published since November 2004

SNIP...

7) EPIDEMIOLOGY AND TRANSMISSION

From enclosures previously used by infected animals

28. Research reviewed in the WIN report showed that healthy cervids could be

infected with CWD by grazing on pastures contaminated with excreta from

infected cervids or with the carcases of diseased cervids. This provided

evidence for environmental transmission of CWD.

29. A more recent experimental study examined the potential for soil to serve as

a reservoir for TSEs by examining the interaction of PrPSc (from an adapted

transmissible mink encephalopathy agent) with common soil minerals

(Johnson et al, 2006). It was demonstrated that substantial PrPSc could be

adsorbed by the clay minerals, kaolinite and montmorillonite as well as

quartz. In addition, significant adsorption to whole soil samples was found.

Furthermore, there was a strong interaction between PrPSc and

montmorillonite. To determine whether prions remained infectious in soil,

clay samples experimentally contaminated with an inoculum were ic

inoculated into hamsters. Symptoms developed in these animals at

approximately the same time as those injected with directly with the inoculum.

The study suggests that TSE infectivity released into soil may be preserved in

a bioavailable form which may contribute to disease transmission. The

authors suggest this study adds to the evidence for environmental

transmission of CWD.


Prions Adhere to Soil Minerals and Remain Infectious 

Christopher J. Johnson1,2, Kristen E. Phillips3, Peter T. Schramm3, Debbie McKenzie2, Judd M. Aiken1,2, Joel A. Pedersen3,4*

1 Program in Cellular and Molecular Biology, University of Wisconsin Madison, Madison, Wisconsin, United States of America, 2 Department of Animal Health and Biomedical Sciences, School of Veterinary Medicine, University of Wisconsin Madison, Madison, Wisconsin, United States of America, 3 Molecular and Environmental Toxicology Center, University of Wisconsin Madison, Madison, Wisconsin, United States of America, 4 Department of Soil Science, University of Wisconsin Madison, Madison, Wisconsin, United States of America

An unidentified environmental reservoir of infectivity contributes to the natural transmission of prion diseases (transmissible spongiform encephalopathies [TSEs]) in sheep, deer, and elk. Prion infectivity may enter soil environments via shedding from diseased animals and decomposition of infected carcasses. Burial of TSE-infected cattle, sheep, and deer as a means of disposal has resulted in unintentional introduction of prions into subsurface environments. We examined the potential for soil to serve as a TSE reservoir by studying the interaction of the disease-associated prion protein (PrPSc) with common soil minerals. In this study, we demonstrated substantial PrPSc adsorption to two clay minerals, quartz, and four whole soil samples. We quantified the PrPSc-binding capacities of each mineral. Furthermore, we observed that PrPSc desorbed from montmorillonite clay was cleaved at an N-terminal site and the interaction between PrPSc and Mte was strong, making desorption of the protein difficult. Despite cleavage and avid binding, PrPSc bound to Mte remained infectious. Results from our study suggest that PrPSc released into soil environments may be preserved in a bioavailable form, perpetuating prion disease epizootics and exposing other species to the infectious agent.

Funding. This work was supported by USEPA grant 4C-R070-NAEX (JAP) and DOD grant DAMD17–03–1–0369 (JMA).

Competing interests. The authors have declared that no competing interests exist.

Editor: David Westaway, University of Toronto, Canada

Received: December 20, 2005; Accepted: March 8, 2006; Published: April 14, 2006

DOI: 10.1371/journal.ppat.0020032

Copyright: © 2006 Johnson et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abbreviations: BH, brain homogenate; BSE, bovine spongiform encephalopathy; CWD, chronic wasting disease; dpi, days postinoculation; Kte, kaolinite; Mte, montmorillonite; PK, proteinase K; PrPC, normal cellular isoform of the prion protein; PrPSc, disease-associated prion protein; TSE, transmissible spongiform encephalopathy

* To whom correspondence should be addressed. E-mail: joelpedersen@wisc.edu

Citation: Johnson CJ, Phillips KE, Schramm PT, McKenzie D, Aiken JM, et al. (2006) Prions Adhere to Soil Minerals and Remain Infectious. PLoS Pathog 2(4): e32

snip...

Discussion Environmental transmission of prion diseases has been noted for decades [7,8,14]. In this study, we provide evidence indicating that soil and soil minerals serve as a reservoir of TSE infectivity. While extrapolation of in vitro studies to the environment must be made with caution, our findings suggest that PrPSc released from diseased animals may be sequestered near the soil surface, maintaining the TSE agent in an environmental medium with which livestock and wildlife come in contact. Our experiments demonstrate that Mte-bound PrPSc remains infectious and suggest that soil may harbor more TSE agent than previously assumed on the basis of water extraction of prions from garden soil [13].

snip...

In conclusion, soil and soil minerals have the potential to bind PrPSc and maintain infectivity. These findings will serve as the basis for further study on the interaction of PrPSc with other soil components (humic substances, quartz, and other minerals), the stability of soil-bound PrPSc under typical environmental conditions (UV light, freeze-thaw cycles) and the effect of soil microorganisms and extracellular enzymes on protein integrity. Our current results suggest that sorption of PrPSc to clay minerals may limit its migration through the soil column. Maintenance of prion infectivity at the soil surface may contribute to the propagation of CWD and scrapie epizootics and enhance the likelihood of interspecies transmission of these diseases.

snip...full text ;


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.

this old study next always stuns me. think of this the next time you clean your tools you use to gut and bone out your kill, and then feeding it to your family and friends...tss

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] 


***> 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

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.

21 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...tss 

***> 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. 


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


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 *** 


CWD CWD CWD PIGS PIGS PIGS SCRAPIE SCRAPIE SCRAPIE

Scrapie, CWD, tse prion, transmit to pigs by oral route

***> 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. 


https://www.ars.usda.gov/research/publications/publication/?seqNo115=353091


MONDAY, NOVEMBER 26, 2018 

***>The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP


PRION CONFERENCE 2018

O3 Experimental studies on prion transmission barrier and TSE pathogenesis in large animals 

Rosa Bolea(1), Acín C(1)Marín B(1), Hedman C(1), Raksa H(1), Barrio T(1), Otero A(1), LópezPérez O(1), Monleón E(1),Martín-Burriel(1), Monzón M(1), Garza MC(1), Filali H(1),Pitarch JL(1), Garcés M(1), Betancor M(1), GuijarroIM(1), GarcíaM(1), Moreno B(1),Vargas A(1), Vidal E(2), Pumarola M(2), Castilla J(3), Andréoletti O(4), Espinosa JC(5), Torres JM(5), Badiola JJ(1). 

1Centro de Investigación en Encefalopatías y Enfermedades Transmisibles Emergentes, VeterinaryFaculty, Universidad de Zaragoza; Zaragoza,Spain.2 RTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB) 3 4 INRA, ÉcoleVétérinaire, Toulouse, France.5CIC bioGUNE, Prion researchlab, Derio, Spain CISA- INIA, Valdeolmos, Madrid 28130, Spain. 

Experimental transmission of Transmissible Spongiform Encephalopathies (TSE) has been understood and related with several factors that could modify the natural development of these diseases. In fact, the behaviour of the natural disease does not match exactly in each animal, being modified by parameters such as the age at infection, the genotype, the breed or the causative strain. Moreover, different TSE strains can target different animal species or tissues, what complicate the prediction of its transmissibility when is tested in a different species of the origin source. The aim of the experimental studies in large animals is to homogenize all those factors, trying to minimize as much as possible variations between individuals. These effects can be flattened by experimental transmission in mice, in which a specific strain can be selected after several passages. With this objective, several experimental studies in large animals have been developed by the presenter research team. 

Classical scrapie agent has been inoculated in cow, with the aim of demonstrate the resistance or susceptibility of this species to the first well known TSE; Atypical scrapie has been inoculated in sheep (using several routes of infection), cow and pig, with the objective of evaluating the potential pathogenicity of this strain; Classical Bovine Spongiform Encephalopathy (BSE) has been inoculated in goats aiming to demonstrate if the genetic background of this species could protect against this strain; goat BSE and sheep BSE have been inoculated in goats and pigs respectively to evaluate the effect of species barrier; and finally atypical BSE has been inoculated in cattle to assess the transmissibility properties of this newly introduced strain. 

Once the experiments have been carried out on large animal species, a collection of samples from animals studied were inoculated in different types of tg mice overexpressing PrPcin order to study the infectivity of the tissues, and also were studied using PMCA. 

In summary, the parameters that have been controlled are the species, the strain, the route of inoculation, the time at infection, the genotype, the age, and the environmental conditions. 

To date, 

***> eleven of the atypical scrapie intracerebrally inoculated sheep have succumbed to atypical scrapie disease; 

***> six pigs to sheep BSE; 

***> one cow to classical scrapie; 

***> nine goats to goat BSE and 

***> five goats to classical BSE. 

***> PrPSC has been demonstrated in all cases by immunohistochemistry and western blot. 

=====> PRION CONFERENCE 2018 


 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.....


TUESDAY, APRIL 18, 2017 

*** EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP ***


TUESDAY, JANUARY 17, 2017 

FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEEDVIOLATIONS OFFICIAL ACTION INDICATED OAI UPDATE 2016 to 2017 BSE TSE PRION


THIS April, 4, 2017 

violation of the mad cow 21 CFR 589.2000 OAI is very serious for the great state of Michigan, some 20 years post FDA mad cow feed of August 1997. if would most likely take a FOIA request and a decade of wrangling to find out more. 

TUESDAY, JANUARY 17, 2017

FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEEDVIOLATIONS OFFICIAL ACTION INDICATED OAI UPDATE 2016 to 2017 BSE TSE PRION

FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEEDVIOLATIONS OFFICIAL ACTION INDICATED OAI UPDATE 2016 to 2017 BSE TSE PRION 

I would kindly like to comment on this FDA BSE/Ruminant Feed Inspections Firms Inventory (excel format)4 format, for reporting these breaches of BSE TSE prion protocols, from the extensive mad cow feed ban warning letters the fda use to put out for each violations. simply put, this excel format sucks, and the FDA et al intentionally made it this difficult to follow the usda fda mad cow follies. this is an intentional format to make it as difficult as possible to follow these breaches of the mad cow TSE prion safety feed protocols. to have absolutely no chronological or numerical order, and to format such violations in a way that they are almost impossible to find, says a lot about just how far the FDA and our fine federal friends will go through to hide these continued violations of the BSE TSE prion mad cow feed ban, and any breaches of protocols there from. once again, the wolf guarding the henhouse $$$

NAI = NO ACTION INDICATED

OAI = OFFICIAL ACTION INDICATED

VAI = VOLUNTARY ACTION INDICATED

RTS = REFERRED TO STATE

OAI (Official Action Indicated) when inspectors find significant objectionable conditions or practices and believe that regulatory sanctions are warranted to address the establishment’s lack of compliance with the regulation. An example of an OAI classification would be findings of manufacturing procedures insufficient to ensure that ruminant feed is not contaminated with prohibited material. Inspectors will promptly re-inspect facilities classified OAI after regulatory sanctions have been applied to determine whether the corrective actions are adequate to address the objectionable conditions. 

2016


ONE more thing, please remember, the label does not have to say ''deer ration'' for cervid to be pumped up with. you can get the same ''high protein'' from many sources of high protein feed for animals other than cattle, and feed them to cervid...

Saturday, August 29, 2009

FOIA REQUEST FEED RECALL 2009 Product may have contained prohibited materials Bulk Whole Barley, Recall # V-256-2009


Friday, September 4, 2009

FOIA REQUEST ON FEED RECALL PRODUCT 429,128 lbs. feed for ruminant animals may have been contaminated with prohibited material Recall # V-258-2009


WEDNESDAY, JULY 11, 2018 

CONFIDENTIAL IN CONFIDENCE SPONGIFORM ENCEPHALOPATHY OF PIGS FDA EMERGENCY REQUEST FOR RULE CHANGE USA Section 21 C.F.R. 589.2000


TUESDAY, JULY 10, 2018 CONFIDENTIAL IN CONFIDENCE SPONGIFORM ENCEPHALOPATHY OF PIGS *** 

''but feeding of other ruminant protein, including scrapie-infected sheep, can continue to pigs.'' 

CONFIDENTIAL 

SPONGIFORM ENCEPHALOPATHY OF PIGS 



***2018***

Cervid to human prion transmission 

Kong, Qingzhong 

Case Western Reserve University, Cleveland, OH, United States

Abstract 

Prion disease is transmissible and invariably fatal. Chronic wasting disease (CWD) is the prion disease affecting deer, elk and moose, and it is a widespread and expanding epidemic affecting 22 US States and 2 Canadian provinces so far. CWD poses the most serious zoonotic prion transmission risks in North America because of huge venison consumption (>6 million deer/elk hunted and consumed annually in the USA alone), significant prion infectivity in muscles and other tissues/fluids from CWD-affected cervids, and usually high levels of individual exposure to CWD resulting from consumption of the affected animal among often just family and friends. However, we still do not know whether CWD prions can infect humans in the brain or peripheral tissues or whether clinical/asymptomatic CWD zoonosis has already occurred, and we have no essays to reliably detect CWD infection in humans. 

We hypothesize that: 

(1) The classic CWD prion strain can infect humans at low levels in the brain and peripheral lymphoid tissues; 

(2) The cervid-to-human transmission barrier is dependent on the cervid prion strain and influenced by the host (human) prion protein (PrP) primary sequence; 

(3) Reliable essays can be established to detect CWD infection in humans; and 

(4) CWD transmission to humans has already occurred. We will test these hypotheses in 4 Aims using transgenic (Tg) mouse models and complementary in vitro approaches. 

Aim 1 will prove that the classical CWD strain may infect humans in brain or peripheral lymphoid tissues at low levels by conducting systemic bioassays in a set of humanized Tg mouse lines expressing common human PrP variants using a number of CWD isolates at varying doses and routes. Experimental human CWD samples will also be generated for Aim 3. 

Aim 2 will test the hypothesis that the cervid-to-human prion transmission barrier is dependent on prion strain and influenced by the host (human) PrP sequence by examining and comparing the transmission efficiency and phenotypes of several atypical/unusual CWD isolates/strains as well as a few prion strains from other species that have adapted to cervid PrP sequence, utilizing the same panel of humanized Tg mouse lines as in Aim 1. 

Aim 3 will establish reliable essays for detection and surveillance of CWD infection in humans by examining in details the clinical, pathological, biochemical and in vitro seeding properties of existing and future experimental human CWD samples generated from Aims 1-2 and compare them with those of common sporadic human Creutzfeldt-Jakob disease (sCJD) prions. 

Aim 4 will attempt to detect clinical CWD-affected human cases by examining a significant number of brain samples from prion-affected human subjects in the USA and Canada who have consumed venison from CWD-endemic areas utilizing the criteria and essays established in Aim 3. The findings from this proposal will greatly advance our understandings on the potential and characteristics of cervid prion transmission in humans, establish reliable essays for CWD zoonosis and potentially discover the first case(s) of CWD infection in humans.

Public Health Relevance

There are significant and increasing human exposure to cervid prions because chronic wasting disease (CWD, a widespread and highly infectious prion disease among deer and elk in North America) continues spreading and consumption of venison remains popular, but our understanding on cervid-to-human prion transmission is still very limited, raising public health concerns. This proposal aims to define the zoonotic risks of cervid prions and set up and apply essays to detect CWD zoonosis using mouse models and in vitro methods. The findings will greatly expand our knowledge on the potentials and characteristics of cervid prion transmission in humans, establish reliable essays for such infections and may discover the first case(s) of CWD infection in humans.

 Funding Agency

Agency

National Institute of Health (NIH)

Institute

National Institute of Neurological Disorders and Stroke (NINDS)

Type

Research Project (R01)

Project #

5R01NS088604-04

Application #

9517118

Study Section

Cellular and Molecular Biology of Neurodegeneration Study Section (CMND)

Program Officer Wong, May

Project Start 2015-09-30 Project End 2019-07-31 Budget Start 2018-08-01 Budget End 2019-07-31 Support Year 4 Fiscal Year 2018 Total Cost Indirect Cost Institution Name Case Western Reserve University Department Pathology Type Schools of Medicine DUNS # 077758407 City Cleveland State OH Country United States Zip Code 44106

 Related projects

NIH 2018 R01 NS Cervid to human prion transmission Kong, Qingzhong / Case Western Reserve University 

NIH 2017 R01 NS Cervid to human prion transmission Kong, Qingzhong / Case Western Reserve University 

NIH 2016 R01 NS Cervid to human prion transmission Kong, Qingzhong / Case Western Reserve University 

NIH 2015 R01 NS Cervid to human prion transmission Kong, Qingzhong / Case Western Reserve University $337,507


ZOONOTIC CHRONIC WASTING DISEASE CWD TSE PRION UPDATE

here is the latest;

PRION 2018 CONFERENCE 

Oral transmission of CWD into Cynomolgus macaques: signs of atypical disease, prion conversion and infectivity in macaques and bio-assayed transgenic mice 

Hermann M. Schatzl, Samia Hannaoui, Yo-Ching Cheng, Sabine Gilch (Calgary Prion Research Unit, University of Calgary, Calgary, Canada) Michael Beekes (RKI Berlin), Walter Schulz-Schaeffer (University of Homburg/Saar, Germany), Christiane Stahl-Hennig (German Primate Center) & Stefanie Czub (CFIA Lethbridge). To date, BSE is the only example of interspecies transmission of an animal prion disease into humans. The potential zoonotic transmission of CWD is an alarming issue and was addressed by many groups using a variety of in vitro and in vivo experimental systems. Evidence from these studies indicated a substantial, if not absolute, species barrier, aligning with the absence of epidemiological evidence suggesting transmission into humans. Studies in non-human primates were not conclusive so far, with oral transmission into new-world monkeys and no transmission into old-world monkeys. Our consortium has challenged 18 Cynomolgus macaques with characterized CWD material, focusing on oral transmission with muscle tissue. Some macaques have orally received a total of 5 kg of muscle material over a period of 2 years. 

After 5-7 years of incubation time some animals showed clinical symptoms indicative of prion disease, and prion neuropathology and PrPSc deposition were detected in spinal cord and brain of some euthanized animals. PrPSc in immunoblot was weakly detected in some spinal cord materials and various tissues tested positive in RT-QuIC, including lymph node and spleen homogenates. To prove prion infectivity in the macaque tissues, we have intracerebrally inoculated 2 lines of transgenic mice, expressing either elk or human PrP. At least 3 TgElk mice, receiving tissues from 2 different macaques, showed clinical signs of a progressive prion disease and brains were positive in immunoblot and RT-QuIC. Tissues (brain, spinal cord and spleen) from these and pre-clinical mice are currently tested using various read-outs and by second passage in mice. Transgenic mice expressing human PrP were so far negative for clear clinical prion disease (some mice >300 days p.i.). In parallel, the same macaque materials are inoculated into bank voles. 

Taken together, there is strong evidence of transmissibility of CWD orally into macaques and from macaque tissues into transgenic mouse models, although with an incomplete attack rate. 

The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology. 

Our ongoing studies will show whether the transmission of CWD into macaques and passage in transgenic mice represents a form of non-adaptive prion amplification, and whether macaque-adapted prions have the potential to infect mice expressing human PrP. 

The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD.. 

***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD. <*** 


READING OVER THE PRION 2018 ABSTRACT BOOK, LOOKS LIKE THEY FOUND THAT from this study ; 

P190 Human prion disease mortality rates by occurrence of chronic wasting disease in freeranging cervids, United States 

Abrams JY (1), Maddox RA (1), Schonberger LB (1), Person MK (1), Appleby BS (2), Belay ED (1) (1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA.. 

SEEMS THAT THEY FOUND Highly endemic states had a higher rate of prion disease mortality compared to non-CWD states. 

AND ANOTHER STUDY; 

P172 Peripheral Neuropathy in Patients with Prion Disease 

Wang H(1), Cohen M(1), Appleby BS(1,2) (1) University Hospitals Cleveland Medical Center, Cleveland, Ohio (2) National Prion Disease Pathology Surveillance Center, Cleveland, Ohio.. 

IN THIS STUDY, THERE WERE autopsy-proven prion cases from the National Prion Disease Pathology Surveillance Center that were diagnosed between September 2016 to March 2017, 

AND 

included 104 patients. SEEMS THEY FOUND THAT The most common sCJD subtype was MV1-2 (30%), followed by MM1-2 (20%), 

AND 

THAT The Majority of cases were male (60%), AND half of them had exposure to wild game. 

snip...see more on Prion 2017 Macaque study from Prion 2017 Conference and other updated science on cwd tse prion zoonosis below...terry 



just out CDC...see;

Research Susceptibility of Human Prion Protein to Conversion by Chronic Wasting Disease Prions 

Marcelo A. Barria

Adriana Libori, Gordon Mitchell, and Mark W. Head Author affiliations: National CJD Research and Surveillance Unit, University of Edinburgh, Edinburgh, Scotland, UK (M.A. Barria, A. Libori, M.W. Head); National and OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada (G. Mitchell) M. A. Barria et al. 

ABSTRACT 

Chronic wasting disease (CWD) is a contagious and fatal neurodegenerative disease and a serious animal health issue for deer and elk in North America. The identification of the first cases of CWD among free-ranging reindeer and moose in Europe brings back into focus the unresolved issue of whether CWD can be zoonotic like bovine spongiform encephalopathy. We used a cell-free seeded protein misfolding assay to determine whether CWD prions from elk, white-tailed deer, and reindeer in North America can convert the human prion protein to the disease-associated form. 

We found that prions can convert, but the efficiency of conversion is affected by polymorphic variation in the cervid and human prion protein genes. In view of the similarity of reindeer, elk, and white-tailed deer in North America to reindeer, red deer, and roe deer, respectively, in Europe, a more comprehensive and thorough assessment of the zoonotic potential of CWD might be warranted. 


Molecular Barriers to Zoonotic Transmission of Prions 

Marcelo A. Barria, Aru Balachandran, Masanori Morita, Tetsuyuki Kitamoto, Rona Barron, Jean Manson, Richard Knight, James W. Ironside, and Mark W. Headcorresponding author 

snip... 

The conversion of human PrPC by CWD brain homogenate in PMCA reactions was less efficient when the amino acid at position 129 was valine rather than methionine. 

***Furthermore, the form of human PrPres produced in this in vitro assay when seeded with CWD, resembles that found in the most common human prion disease, namely sCJD of the MM1 subtype. 

snip... 

However, we can say with confidence that under the conditions used here, none of the animal isolates tested were as efficient as C-type BSE in converting human PrPC, which is reassuring. 

***Less reassuring is the finding that there is no absolute barrier to the conversion of human PrPC by CWD prions in a protocol using a single round of PMCA and an entirely human substrate prepared from the target organ of prion diseases, the brain. 


Prion 2017 Conference Abstracts 

CWD 2017 PRION CONFERENCE 

First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress

Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1 University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen 

This is a progress report of a project which started in 2009. 

21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. 

Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. 

Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). 

Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. 

We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves. 

Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. 

Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. 

All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. 

Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice. 

At present, a total of 10 animals are sacrificed and read-outs are ongoing. 

Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10 years. 

Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation. 

PRION 2017 

DECIPHERING NEURODEGENERATIVE DISORDERS 

Subject: PRION 2017 CONFERENCE 

DECIPHERING NEURODEGENERATIVE DISORDERS 

VIDEO PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS 

*** PRION 2017 CONFERENCE VIDEO 



ZOONOTIC, ZOONOSIS, CHRONIC WASTING DISEASE CWD TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION 

10. ZOONOTIC, ZOONOSIS, CHRONIC WASTING DISEASE CWD TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION AKA MAD DEER ELK DISEASE IN HUMANS, has it already happened, that should be the question... 

''In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids.'' Scientific opinion on chronic wasting disease (II)

EFSA Panel on Biological Hazards (BIOHAZ) Antonia Ricci Ana Allende Declan Bolton Marianne Chemaly Robert Davies Pablo Salvador Fernández Escámez ... See all authors 

First published: 17 January 2018 https://doi.org/10.2903/j.efsa.2018.5132 

also, see; 

8. Even though human TSE‐exposure risk through consumption of game from European cervids can be assumed to be minor, if at all existing, no final conclusion can be drawn due to the overall lack of scientific data. In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids. It might be prudent considering appropriate measures to reduce such a risk, e.g. excluding tissues such as CNS and lymphoid tissues from the human food chain, which would greatly reduce any potential risk for consumers.. However, it is stressed that currently, no data regarding a risk of TSE infections from cervid products are available. 

snip... 

The tissue distribution of infectivity in CWD‐infected cervids is now known to extend beyond CNS and lymphoid tissues. While the removal of these specific tissues from the food chain would reduce human dietary exposure to infectivity, exclusion from the food chain of the whole carcass of any infected animal would be required to eliminate human dietary exposure. 


zoonosis zoonotic cervid tse prion cwd to humans, preparing for the storm 

***An alternative to modeling the species barrier is the cell-free conversion assay which points to CWD as the animal prion disease with the greatest zoonotic potential, after (and very much less than) BSE..116*** 


 To date there is no direct evidence that CWD has been or can be transmitted from animals to humans. 

However, initial findings from a laboratory research project funded by the Alberta Prion Research Institute (APRI) and Alberta Livestock Meat Agency (ALMA), and led by a Canadian Food Inspection Agency (CFIA) scientist indicate that CWD has been transmitted to cynomolgus macaques (the non-human primate species most closely related to humans that may be used in research), through both the intracranial and oral routes of exposure. 

Both infected brain and muscle tissues were found to transmit disease. 

Health Canada’s Health Products and Food Branch (HPFB) was asked to consider the impact of these findings on the Branch’s current position on CWD in health products and foods. 

Summary and Recommendation: 

snip...

Health Portfolio partners were recently made aware of initial findings from a research project led by a CFIA scientist that have demonstrated that cynomolgus macaques can be infected via intracranial exposure and oral gavage with CWD infected muscle. 

These findings suggest that CWD, under specific experimental conditions, has the potential to cross the human species barrier, including by enteral feeding of CWD infected muscle. 


*** WDA 2016 NEW YORK *** 

We found that CWD adapts to a new host more readily than BSE and that human PrP was unexpectedly prone to misfolding by CWD prions. 

In addition, we investigated the role of specific regions of the bovine, deer and human PrP protein in resistance to conversion by prions from another species. 

***We have concluded that the human protein has a region that confers unusual susceptibility to conversion by CWD prions. 

Student Presentations Session 2 

The species barriers and public health threat of CWD and BSE prions 

Ms. Kristen Davenport1, Dr. Davin Henderson1, Dr. Candace Mathiason1, Dr. Edward Hoover1 1Colorado State University 

Chronic wasting disease (CWD) is spreading rapidly through cervid populations in the USA. Bovine spongiform encephalopathy (BSE, mad cow disease) arose in the 1980s because cattle were fed recycled animal protein. 

These and other prion diseases are caused by abnormal folding of the normal prion protein (PrP) into a disease causing form (PrPd), which is pathogenic to nervous system cells and can cause subsequent PrP to misfold. CWD spreads among cervids very efficiently, but it has not yet infected humans. On the other hand, BSE was spread only when cattle consumed infected bovine or ovine tissue, but did infect humans and other species. 

The objective of this research is to understand the role of PrP structure in cross-species infection by CWD and BSE. To study the propensity of each species’ PrP to be induced to misfold by the presence of PrPd from verious species, we have used an in vitro system that permits detection of PrPd in real-time. 

We measured the conversion efficiency of various combinations of PrPd seeds and PrP substrate combinations. 

We observed the cross-species behavior of CWD and BSE, in addition to feline-adapted CWD and BSE. We found that CWD adapts to a new host more readily than BSE and that human PrP was unexpectedly prone to misfolding by CWD prions. In addition, we investigated the role of specific regions of the bovine, deer and human PrP protein in resistance to conversion by prions from another species. 

***We have concluded that the human protein has a region that confers unusual susceptibility to conversion by CWD prions. CWD is unique among prion diseases in its rapid spread in natural populations. BSE prions are essentially unaltered upon passage to a new species, while CWD adapts to the new species. This adaptation has consequences for surveillance of humans exposed to CWD. Wildlife Disease Risk Communication Research Contributes to Wildlife Trust Administration Exploring perceptions about chronic wasting disease risks among wildlife and agriculture professionals and stakeholders 


TUESDAY, SEPTEMBER 12, 2017 

CDC Now Recommends Strongly consider having the deer or elk tested for CWD before you eat the meat 


***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.*** 


CDC CWD TSE PRION UPDATE USA JANUARY 2018

As of January 2018, CWD in free-ranging deer, elk and/or moose has been reported in at least 22 states in the continental United States, as well as two provinces in Canada. In addition, CWD has been reported in reindeer and moose in Norway, and a small number of imported cases have been reported in South Korea. The disease has also been found in farmed deer and elk. CWD was first identified in captive deer in the late 1960s in Colorado and in wild deer in 1981. By the 1990s, it had been reported in surrounding areas in northern Colorado and southern Wyoming. Since 2000, the area known to be affected by CWD in free-ranging animals has increased to at least 22 states, including states in the Midwest, Southwest, and limited areas on the East Coast.. It is possible that CWD may also occur in other states without strong animal surveillance systems, but that cases haven’t been detected yet. Once CWD is established in an area, the risk can remain for a long time in the environment. The affected areas are likely to continue to expand. Nationwide, the overall occurrence of CWD in free-ranging deer and elk is relatively low. However, in several locations where the disease is established, infection rates may exceed 10 percent (1 in 10), and localized infection rates of more than 25 percent (1 in 4) have been reported. The infection rates among some captive deer can be much higher, with a rate of 79% (nearly 4 in 5) reported from at least one captive herd. As of January 2018, there were 186 counties in 22 states with reported CWD in free-ranging cervids... 

Chronic Wasting Disease Among Free-Ranging Cervids by County, United States, January 2018 

snip.... 


*** 2017-2018 CWD TSE Prion UPDATE


 why do we not want to do TSE transmission studies on chimpanzees $

5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. 

***> I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. 

***> Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.

snip...


ZOONOSIS OF SCRAPIE TSE PRION

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. 

============== 


***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice. 

***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion. 

***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions. 


PRION 2016 TOKYO

Saturday, April 23, 2016

SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016

Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online

Taylor & Francis

Prion 2016 Animal Prion Disease Workshop Abstracts

WS-01: Prion diseases in animals and zoonotic potential

Juan Maria Torres a, Olivier Andreoletti b, J uan-Carlos Espinosa a. Vincent Beringue c. Patricia Aguilar a,

Natalia Fernandez-Borges a. and Alba Marin-Moreno a

"Centro de Investigacion en Sanidad Animal ( CISA-INIA ). Valdeolmos, Madrid. Spain; b UMR INRA -ENVT 1225 Interactions Holes Agents Pathogenes. ENVT. Toulouse. France: "UR892. Virologie lmmunologie MolécuIaires, Jouy-en-Josas. France

Dietary exposure to bovine spongiform encephalopathy (BSE) contaminated bovine tissues is considered as the origin of variant Creutzfeldt Jakob (vCJD) disease in human. To date, BSE agent is the only recognized zoonotic prion... Despite the variety of Transmissible Spongiform Encephalopathy (TSE) agents that have been circulating for centuries in farmed ruminants there is no apparent epidemiological link between exposure to ruminant products and the occurrence of other form of TSE in human like sporadic Creutzfeldt Jakob Disease (sCJD). However, the zoonotic potential of the diversity of circulating TSE agents has never been systematically assessed. The major issue in experimental assessment of TSEs zoonotic potential lies in the modeling of the ‘species barrier‘, the biological phenomenon that limits TSE agents’ propagation from a species to another. In the last decade, mice genetically engineered to express normal forms of the human prion protein has proved essential in studying human prions pathogenesis and modeling the capacity of TSEs to cross the human species barrier.

To assess the zoonotic potential of prions circulating in farmed ruminants, we study their transmission ability in transgenic mice expressing human PrPC (HuPrP-Tg). Two lines of mice expressing different forms of the human PrPC (129Met or 129Val) are used to determine the role of the Met129Val dimorphism in susceptibility/resistance to the different agents.

These transmission experiments confirm the ability of BSE prions to propagate in 129M- HuPrP-Tg mice and demonstrate that Met129 homozygotes may be susceptible to BSE in sheep or goat to a greater degree than the BSE agent in cattle and that these agents can convey molecular properties and neuropathological indistinguishable from vCJD. However homozygous 129V mice are resistant to all tested BSE derived prions independently of the originating species suggesting a higher transmission barrier for 129V-PrP variant.

Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice. 

Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion. 

These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions. 

why do we not want to do TSE transmission studies on chimpanzees $

5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. 

***> I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. 

***> Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.

snip...

R. BRADLEY



Title: Transmission of scrapie prions to primate after an extended silent incubation period) 

*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS. 

*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated. 

*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains. 


*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies. 


2018

Cervid to human prion transmission 5R01NS088604-04 Update

National Institute of Health (NIH)


SATURDAY, JANUARY 27, 2018 

CDC CHRONIC WASTING DISEASE CWD TSE PRION UPDATE REPORT USA JANUARY 2018


FRIDAY, MARCH 30, 2018 

Docket No. APHIS-2018-0011 Chronic Wasting Disease Herd Certification Program Standards Singeltary Submission March 30, 2018





FRIDAY, JANUARY 04, 2019 

TEXAS TPWD CONFIRMED CWD TSE PRION 3 WTD in Medina, Dallam, and Hartley Counties, and in 3 MD in Hudspeth, Hartley, and El Paso Counties


FRIDAY, DECEMBER 28, 2018 

***> Chronic Wasting Disease CWD TSE Prion 2019 Where The Rubber Meets The Road 


FRIDAY, DECEMBER 14, 2018 

MAD COW USA FLASHBACK FRIDAY DECEMBER 14, 2018


THURSDAY, JANUARY 3, 2019 

MAD COW USDA DISEASE BSE TSE Prion 


Saturday, December 15, 2018 

***> ADRD Summit RFI Singeltary COMMENT SUBMISSION BSE, SCRAPIE, CWD, AND HUMAN TSE PRION DISEASE December 14, 2018


TUESDAY, JANUARY 1, 2019 

CHILDHOOD EXPOSURE TO CADAVERIC DURA


Terry S. Singeltary Sr., Bacliff, Texas, USA, 77518, Galveston Bay...on the bottom.

No comments:

Post a Comment