Horizontal Transmission of Chronic Wasting Disease in Reindeer CDC Volume 22, Number 12—December 2016

Volume 22, Number 12—December 2016

Dispatch

Horizontal Transmission of Chronic Wasting Disease in Reindeer

S. Jo Moore, Robert Kunkle, M. Heather West Greenlee, Eric Nicholson, Jürgen Richt, Amir Hamir¹, W. Ray Waters, and Justin Greenlee(http://wwwnc.cdc.gov/eid/article/22/12/16-0635_article#comment) 

Author affiliations: US Department of Agriculture, Ames, Iowa, USA (S.J. Moore, R. Kunkle, E. Nicholson, J. Richt, A. Hamir, W.R. Waters, J. Greenlee):; Iowa State University, Ames (M.H. West Greenlee)

Suggested citation for this article

Abstract

We challenged reindeer by the intracranial route with the agent of chronic wasting disease sourced from white-tailed deer, mule deer, or elk and tested for horizontal transmission to naive reindeer. Reindeer were susceptible to chronic wasting disease regardless of source species. Horizontal transmission occurred through direct contact or indirectly through the environment.

Reindeer are susceptible to chronic wasting disease (CWD) after experimental oral challenge (1), and recently, CWD was identified in a free-ranging reindeer in Norway (2,3). Horizontal transmission is the primary mode of CWD transmission in deer. Direct horizontal transmission occurs when naive animals are exposed to infectious excreta (i.e., saliva, urine, feces) during close contact with CWD-affected animals (reviewed in 4). Indirect horizontal transmission occurs through exposure to environments contaminated with infectious material (e.g., excreta or decomposed carcasses) (5,6).

The Eurasian reindeer (Rangifer tarundus tarundus) is closely related to the North American caribou (R. t. caribou, R. t. granti, R. t. groenlandicus). In North America, overlapping geographic ranges of free-ranging populations of potentially CWD-infected white-tailed deer (Odocoileus virginianus), mule deer (O. hemionus), or elk (Cervus elaphus nelsoni) present a risk for horizontal transmission to caribou. Exposure also could occur in farmed populations where contact occurs between reindeer and captive and/or free-ranging CWD-affected cervids. We investigated the transmission of CWD from white-tailed deer, mule deer, or elk to reindeer through the intracranial route and assessed them for direct and indirect horizontal transmission to uninoculated sentinels.

The Study

Figure 1

Figure 1(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-f1). Immunohistochemical analysis for the prion protein showing scrapie prion protein (PrP^Sc) deposits in brains (A–D) and retinas (E, F) from reindeer (Rangifer tarandus tarandus) with chronic wasting disease. PrP^Sc immunodetection using...

In 2005, we challenged reindeer fawns from a farm in Alaska, USA, where CWD had never been reported, by intracranial inoculation (7) with pooled brain material from CWD-affected elk from South Dakota (CWD^elk), CWD-affected mule deer from Wyoming (CWD^md), or CWD from white-tailed deer from Wisconsin combined with brain material from experimentally challenged white-tailed deer (CWD^wtd) (Table 1(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t1); Technical Appendix[PDF - 251 KB - 7 pages](http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf)). Additional uninoculated fawns served as negative controls, controls for indirect transmission, and controls for direct transmission (Table 1(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t1); online Technical Appendix). We determined the prion protein gene (PRNP) genotype of each fawn (Technical Appendix[PDF - 251 KB - 7 pages](http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf)), and we tried to ensure that each PRNP genotype was present in each group (Table 2(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t2)). Control reindeer were housed in the same barn as inoculated reindeer but in separate pens that prevented direct physical contact (i.e., nose-to-nose) between control and inoculated animals (Technical Appendix[PDF - 251 KB - 7 pages](http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf) Figure 1). Indirect and direct contact control groups were formed 25 months after intracranially challenged reindeer were inoculated (Technical Appendix[PDF - 251 KB - 7 pages](http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf) Figure 1, panel B).

Clinical signs consistent with CWD were first observed 20.9 months after inoculation (Table 2(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t2)). Common clinical features included found dead without clinical signs noted, loss of body condition, recumbency, and lethargy (Table 2(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t2); online Technical Appendix).

At death, a full necropsy was performed on all reindeer. Two sets of tissue samples were collected: 1 set was fixed in 10% buffered formalin, embedded in paraffin wax, sectioned at 5 μm for microscopy examination after hematoxylin and eosin staining or immunohistochemical staining using primary antibody F99/96.7.1 (Technical Appendix[PDF - 251 KB - 7 pages](http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf)). A second set of tissues was frozen, and selected tissues were used for immunodetection of scrapie prion protein (PrP^Sc) by Western blot (brain tissue only) as described previously (7) but with some modifications, or an ELISA (brainstem and/or retropharyngeal lymph node) using a commercial kit (IDEXX HerdChek BSE-Scrapie Antigen ELISA; IDEXX, Westbrook, ME, USA) according to the manufacturers’ instructions (Technical Appendix[PDF - 251 KB - 7 pages](http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf)).

In the intracranially inoculated groups, when intercurrent deaths were excluded, reindeer with the NN138 polymorphism (reindeer nos. 2, 6, and 12) had the shortest survival times in each group (Table 2(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t2)). Different inocula did not produce significantly different survival times (log-rank test, p = 0.0931), but we observed differences in the amount of vacuolation and PrP^Sc in the brain at the clinical stages of disease in CWD^wtd- and CWD^elk-inoculated reindeer, compared with CWD^md-inoculated reindeer (Table 2(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t2); Technical Appendix[PDF - 251 KB - 7 pages](http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf)). In the indirect contact animals, PrP^Sc was present in the brain but restricted to the dorsal motor nucleus of the vagus nerve and area postrema.

We observed different patterns of PrP^Sc deposition in the brain (Figure 1, panels A–D; Technical Appendix[PDF - 251 KB - 7 pages](http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf)), the most striking of which was dominated by aggregated deposits of various sizes, including plaque-like deposits (Figure 1, panels A,B). This pattern was seen in reindeer with the NS138 NN176 (no. 8, CWD^elk; no. 13, CWD^md) or SS138 DD176 (no. 4, CWD^wtd) genotypes. With regard to immunoreactivity in the retina (Figure 1, panels E, F; online Technical Appendix), in 2 of 3 reindeer with aggregated deposits in the brain (nos. 8 and 13), aggregated immunoreactivity also was observed in the inner plexiform layer of the retina (Figure 1, panel f).

Figure 2

Figure 2(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-f2). Western blot characterization of the inocula used to inoculate reindeer and brainstem samples from representative reindeer from each experimental group in study of chronic wasting disease transmission. Scrapie prion protein (PrP^Sc)...

Reindeer that were negative by immunohistochemical analysis in brain also were negative by Western blot and ELISA. Different Western blot migration patterns were observed in PrP^Sc-positive animals (Figure 2), but we found no clear association between migration pattern and challenge group or PRNP genotype.

PrP^Sc was widespread in lymphoid tissues from most reindeer (Table 2(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t2); online Technical Appendix). Reindeer with the NS138 genotype had a significantly lower average percentage of lymphoid follicles positive than did reindeer with NN138 (analysis of variance, p = 0.003) or SS138 (p = 0.003) deer. Excluding intercurrent deaths, PrP^Sc was detected in all 4 CWD^wtd-challenged reindeer, all 5 CWD^elk-challenged reindeer, all 4 CWD^md-challenged reindeer, both indirect contact reindeer, and 2 of 4 direct contact reindeer (Table 2(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t2)).

Conclusions

Potential sources of infectivity for direct contact animals include urine, feces, and saliva from their CWD^wtd-challenged pen-mates, as has been shown for CWD-affected white-tailed deer (6,8,9). Pinpointing the source of infectivity in the indirect contact group is more difficult. Infectious prions can travel at least 30 m in airborne particulate (10), but because the negative control reindeer in the pen adjacent to the indirect contact reindeer did not become positive, a more direct route of transmission is likely in this case. Penning, feeding, and watering protocols were designed to prevent exposure of negative control and indirect contact reindeer to potential infectivity on feed and water buckets, bedding, or fencing (6,11). However, reindeer might have had access to bedding from adjacent pens that had spread into the central alleyway.

During the 5-year course of this study, reindeer were moved between pens several times to maintain an optimal number of animals per pen (Technical Appendix[PDF - 251 KB - 7 pages](http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf) Figure 1). Prolonged persistence of prion infectivity in the natural environment has been documented for both CWD (2 years [5]) and scrapie (up to 16 years [12]). In addition, thorough cleaning and disinfection might not be sufficient to remove all infectivity from the environment, leading to persistence of infectivity under experimental housing conditions (13).

In reindeer challenged orally with the agent of CWD, the SS138 genotype (serine/serine at PRNP codon 138) has been associated with susceptibility to disease and the NS138 (asparagine/serine) genotype with resistance (1). In the study we report, disease developed in reindeer with the NS138 genotype after intracranial inoculation, although the extent of lymphoreticular system involvement was significantly lower than in NN138 and SS138 reindeer. The potential association of the NN138 polymorphism with shorter survival times is interesting. However, as with all potential genotype versus phenotype interactions, care should be taken not to over-interpret these results given the small group sizes and the large number of PRNP genotype groups in this study.

Our results demonstrate that reindeer are susceptible to the agent of CWD from white-tailed deer, mule deer, and elk sources after intracranial inoculation. Furthermore, naive reindeer are susceptible to the agent of CWD after direct and indirect exposure to CWD-infected reindeer, suggesting a high potential for horizontal transmission of CWD within and between farmed and free-ranging reindeer (and caribou) populations.

Dr. Moore is a postdoctoral research associate at the National Animal Disease Center, US Department of Agriculture, Ames, Iowa. Her research interests include pathogenesis and pathology of animal diseases with a special interest in neuropathology and prion diseases.

On This Page

·         The Study

·         Conclusions

·         Suggested Citation

Figures

·         Figure 1(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-f1)

·         Figure 2(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-f2)

Tables

·         Table 1(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t1)

·         Table 2(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t2)

Technical Appendices

·         Technical Appendix(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf)

Downloads

·         RIS[TXT - 2 KB] (http://wwwnc.cdc.gov/eid/article/22/12/16-0635.ris)

Acknowledgment

We thank Martha Church, Robyn Kokemuller, Joe Lesan, Virginia Montgomery, Dennis Orcutt, and Trudy Tatum for excellent technical support.

References

1.       Mitchell GB, Sigurdson CJ, O’Rourke KI, Algire J, Harrington NP, Walther I, Experimental oral transmission of chronic wasting disease to reindeer (Rangifer tarandus tarandus). PLoS One. 2012;7:e39055.DOIPubMed

2.      Norwegian Veterinary Institute. The first detection of chronic wasting disease (CWD) in Europe. 2016 April 4 [cited 2016 Apr 5]. http://www.vetinst.no/sykdom-og-agens/chronic-wasting-disease/the-first-detection-of-chronic-wasting-disease-cwd-in-europe

3.      Becker R. Deadly animal prion disease appears in Europe. 2016 [cited 2016 Jun 16]. http://www.nature.com/news/deadly-animal-prion-disease-appears-in-europe-1.19759

4.      Haley NJ, Hoover EA. Chronic wasting disease of cervids: current knowledge and future perspectives. Annu Rev Anim Biosci. 2015;3:305–25.DOIPubMed

5.      Miller MW, Williams ES, Hobbs NT, Wolfe LL. Environmental sources of prion transmission in mule deer. Emerg Infect Dis. 2004;10:1003–6.DOIPubMed

6.      Henderson DM, Denkers ND, Hoover CE, Garbino N, Mathiason CK, Hoover EA. Longitudinal detection of prion shedding in saliva and urine by CWD-infected deer by real-time quaking-induced conversion. J Virol. 2015;89:9338–47.DOIPubMed

7.      Greenlee JJ, Smith JD, Kunkle RA. White-tailed deer are susceptible to the agent of sheep scrapie by intracerebral inoculation. Vet Res. 2011;42:107.DOIPubMed

8.     Mathiason CK, Hays SA, Powers J, Hayes-Klug J, Langenberg J, Dahmes SJ, Infectious prions in pre-clinical deer and transmission of chronic wasting disease solely by environmental exposure. PLoS One. 2009;4:e5916.DOIPubMed

9.      Tamgüney G, Richt JA, Hamir AN, Greenlee JJ, Miller MW, Wolfe LL, Salivary prions in sheep and deer. Prion. 2012;6:52–61.DOIPubMed

10.  Gough KC, Baker CA, Simmons HA, Hawkins SA, Maddison BC. Circulation of prions within dust on a scrapie affected farm. Vet Res. 2015;46:40.DOIPubMed

11.   Maddison BC, Baker CA, Terry LA, Bellworthy SJ, Thorne L, Rees HC, Environmental sources of scrapie prions. J Virol. 2010;84:11560–2.DOIPubMed

12.  Georgsson G, Sigurdarson S, Brown P. Infectious agent of sheep scrapie may persist in the environment for at least 16 years. J Gen Virol. 2006;87:3737–40.DOIPubMed

13.  Hawkins SA, Simmons HA, Gough KC, Maddison BC. Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination. Vet Rec. 2015;176:99.DOIPubMed

Figures

·         Figure 1. Immunohistochemical analysis for the prion protein showing scrapie prion protein (PrP^Sc) deposits in brains (A–D) and retinas (E, F) from reindeer (Rangifer tarandus tarandus) with chronic wasting disease. PrP^Sc...(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-f1)

·         Figure 2. Western blot characterization of the inocula used to inoculate reindeer and brainstem samples from representative reindeer from each experimental group in study of chronic wasting disease transmission. Scrapie prion...(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-f2)

Tables

·         Table 1. Animal data for reindeer (Rangifer tarandus tarandus) in a study of transmission of CWD (http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t1)

·         Table 2. Resutls of tissue testing for chronic wasting disease in reindeer based on immunohistochemical detection of PrP^Sc, assessment of spongiform change in formalin-fixed tissues, or both (http://wwwnc.cdc.gov/eid/article/22/12/16-0635-t2)

Technical Appendix

·         Technical Appendix. Additional materials and methods and results from a study of horizontal transmission of chronic wasting disease among reindeer.  251 KB(http://wwwnc.cdc.gov/eid/article/22/12/16-0635-techapp1.pdf)

Suggested citation for this article: Moore SJ, Kunkle R, West Greenlee MH, Nicholson E, Richt J, Hamir et al. Horizontal transmission of chronic wasting disease in reindeer. Emerg Infect Dis. 2016 Dec [date cited]. http://dx.doi.org/10.3201/eid2212.160635

DOI: 10.3201/eid2212.160635

¹Deceased.

Table of Contents – Volume 22, Number 12—December 2016(http://wwwnc.cdc.gov/eid/articles/issue/22/12/table-of-contents)

http://wwwnc.cdc.gov/eid/article/22/12/16-0635_article

Wednesday, November 09, 2016

Norway and Finland Rule Changes for importation and exportation of deer to limit the spread of skrantesjuke (CWD)

http://chronic-wasting-disease.blogspot.com/2016/11/norway-and-finland-rule-changes-for.html

Title: Pathological features of chronic wasting disease in reindeer and demonstration of horizontal transmission

https://www.ars.usda.gov/research/publications/publication/?seqNo115=328261

Monday, September 05, 2016

Pathological features of chronic wasting disease in reindeer and demonstration of horizontal transmission Major Findings for Norway

http://chronic-wasting-disease.blogspot.com/2016/09/pathological-features-of-chronic.html

Thursday, September 22, 2016

NORWAY DETECTS 5TH CASE OF CHRONIC WASTING DISEASE CWD TSE PRION Skrantesjuke

http://chronic-wasting-disease.blogspot.com/2016/09/norway-detects-5th-case-of-chronic.html

SUNDAY, OCTOBER 02, 2016

*** What is the risk of a cervid TSE being introduced from Norway into Great Britain? Qualitative Risk Assessment September 2016

http://chronic-wasting-disease.blogspot.com/2016/10/what-is-risk-of-cervid-tse-being.html

Wednesday, September 7, 2016

*** An assessment of the long-term persistence of prion infectivity in aquatic environments

http://transmissiblespongiformencephalopathy.blogspot.com/2016/09/an-assessment-of-long-term-persistence.html

Friday, September 02, 2016

*** Chronic Wasting Disease Drives Population Decline of White-Tailed Deer

http://chronic-wasting-disease.blogspot.com/2016/09/chronic-wasting-disease-drives.html

*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years ***

Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3

http://jgv.sgmjournals.org/content/87/12/3737.full

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.

https://prion2015.files.wordpress.com/2015/05/programguide1.pdf

see ;

with CWD TSE Prions, I am not sure there is any absolute yet, other than what we know with transmission studies, and we know tse prion kill, and tse prion are bad. science shows to date, that indeed soil, dirt, some better than others, can act as a carrier. same with objects, farm furniture. take it with how ever many grains of salt you wish, or not. if load factor plays a role in the end formula, then everything should be on the table, in my opinion. see ; ***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.

https://prion2015.files.wordpress.com/2015/05/programguide1.pdf

see ;

http://www.tandfonline.com/doi/pdf/10.4161/pri.28467

Oral Transmissibility of Prion Disease Is Enhanced by Binding to Soil Particles

Author Summary

Transmissible spongiform encephalopathies (TSEs) are a group of incurable neurological diseases likely caused by a misfolded form of the prion protein. TSEs include scrapie in sheep, bovine spongiform encephalopathy (‘‘mad cow’’ disease) in cattle, chronic wasting disease in deer and elk, and Creutzfeldt-Jakob disease in humans. Scrapie and chronic wasting disease are unique among TSEs because they can be transmitted between animals, and the disease agents appear to persist in environments previously inhabited by infected animals. Soil has been hypothesized to act as a reservoir of infectivity and to bind the infectious agent. In the current study, we orally dosed experimental animals with a common clay mineral, montmorillonite, or whole soils laden with infectious prions, and compared the transmissibility to unbound agent. We found that prions bound to montmorillonite and whole soils remained orally infectious, and, in most cases, increased the oral transmission of disease compared to the unbound agent. The results presented in this study suggest that soil may contribute to environmental spread of TSEs by increasing the transmissibility of small amounts of infectious agent in the environment.

https://www.aphis.usda.gov/emergency_response/downloads/tools/johnson%20et%20al%20prions%20in%20soil.pdf

tse prion soil

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0058630

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3567181/pdf/ppat.1003113.pdf

http://www.nature.com/srep/2015/150210/srep08358/full/srep08358.html?WT.ec_id=SREP-639-20150217

http://www.cell.com/cell-reports/pdfExtended/S2211-1247(15)00437-4

Wednesday, December 16, 2015

Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission

http://journal.frontiersin.org/article/10.3389/fvets.2015.00032/full

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.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4397813/pdf/13567_2015_Article_176.pdf

>>>Particle-associated PrPTSE molecules may migrate from locations of deposition via transport processes affecting soil particles, including entrainment in and movement with air and overland flow. <<<

Fate of Prions in Soil: A Review

Christen B. Smith, Clarissa J. Booth, and Joel A. Pedersen*

Several reports have shown that prions can persist in soil for several years. Significant interest remains in developing methods that could be applied to degrade PrPTSE in naturally contaminated soils. Preliminary research suggests that serine proteases and the microbial consortia in stimulated soils and compost may partially degrade PrPTSE. Transition metal oxides in soil (viz. manganese oxide) may also mediate prion inactivation. Overall, the effect of prion attachment to soil particles on its persistence in the environment is not well understood, and additional study is needed to determine its implications on the environmental transmission of scrapie and CWD.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160281/

P.161: Prion soil binding may explain efficient horizontal CWD transmission

Conclusion. Silty clay loam exhibits highly efficient prion binding, inferring a durable environmental reservoir, and an efficient mechanism for indirect horizontal CWD transmission.

https://prion2015.files.wordpress.com/2015/05/prion2015abstracts.pdf

>>>Another alternative would be an absolute prohibition on the movement of deer within the state for any purpose. While this alternative would significantly reduce the potential spread of CWD, it would also have the simultaneous effect of preventing landowners and land managers from implementing popular management strategies involving the movement of deer, and would deprive deer breeders of the ability to engage in the business of buying and selling breeder deer. Therefore, this alternative was rejected because the department determined that it placed an avoidable burden on the regulated community.<<<

Wednesday, December 16, 2015

Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission

Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission

Timm Konold1*, Stephen A. C. Hawkins2, Lisa C. Thurston3, Ben C. Maddison4, Kevin C. Gough5, Anthony Duarte1 and Hugh A. Simmons1

1 Animal Sciences Unit, Animal and Plant Health Agency Weybridge, Addlestone, UK, 2 Pathology Department, Animal and Plant Health Agency Weybridge, Addlestone, UK, 3 Surveillance and Laboratory Services, Animal and Plant Health Agency Penrith, Penrith, UK, 4 ADAS UK, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, UK, 5 School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, UK Classical scrapie is an environmentally transmissible prion disease of sheep and goats. Prions can persist and remain potentially infectious in the environment for many years and thus pose a risk of infecting animals after re-stocking. In vitro studies using serial protein misfolding cyclic amplification (sPMCA) have suggested that objects on a scrapie affected sheep farm could contribute to disease transmission. This in vivo study aimed to determine the role of field furniture (water troughs, feeding troughs, fencing, and other objects that sheep may rub against) used by a scrapie-infected sheep flock as a vector for disease transmission to scrapie-free lambs with the prion protein genotype VRQ/VRQ, which is associated with high susceptibility to classical scrapie. When the field furniture was placed in clean accommodation, sheep became infected when exposed to either a water trough (four out of five) or to objects used for rubbing (four out of seven). This field furniture had been used by the scrapie-infected flock 8 weeks earlier and had previously been shown to harbor scrapie prions by sPMCA. Sheep also became infected (20 out of 23) through exposure to contaminated field furniture placed within pasture not used by scrapie-infected sheep for 40 months, even though swabs from this furniture tested negative by PMCA. This infection rate decreased (1 out of 12) on the same paddock after replacement with clean field furniture. Twelve grazing sheep exposed to field furniture not in contact with scrapie-infected sheep for 18 months remained scrapie free. The findings of this study highlight the role of field furniture used by scrapie-infected sheep to act as a reservoir for disease re-introduction although infectivity declines considerably if the field furniture has not been in contact with scrapie-infected sheep for several months. PMCA may not be as sensitive as VRQ/VRQ sheep to test for environmental contamination.

snip...

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

http://journal.frontiersin.org/article/10.3389/fvets.2015.00032/full

Wednesday, December 16, 2015

*** Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission ***

http://scrapie-usa.blogspot.com/2015/12/objects-in-contact-with-classical.html

*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years ***

Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3

http://jgv.sgmjournals.org/content/87/12/3737.full

2016 Comment from Terry Singeltary Sr.

The is a Comment on the Food and Drug Administration (FDA) Notice: 158 Guidance for Industry Use of Material from Deer and Elk in Animal Feed

https://www.regulations.gov/document?D=FDA-2003-D-0432-0011

DOCKET-- 03D-0186 -- FDA Issues Draft Guidance on Use of Material From Deer and Elk in Animal Feed; Availability Date: Fri, 16 May 2003 11:47:37 0500 EMC 1 Terry S. Singeltary Sr. Vol #: 1

http://www.fda.gov/ohrms/dockets/dailys/03/Jun03/060903/060903.htm

http://www.fda.gov/ohrms/dockets/dailys/03/oct03/100203/100203.htm

PLEASE SEE FULL TEXT SUBMISSION ;

http://madcowfeed.blogspot.com/2008/07/docket-03d-0186-fda-issues-draft.html

*** 2001 Terry S. Singeltary Sr. comment submission ***

http://www.fda.gov/ohrms/dockets/ac/01/slides/3681s2_09.pdf

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.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4397813/pdf/13567_2015_Article_176.pdf

Saturday, December 12, 2015

NOTICE: Environmental Impact Statement on Large Livestock Carcasses TSE Prion REPORT December 14, 2015

http://transmissiblespongiformencephalopathy.blogspot.com/2015/12/notice-environmental-impact-statement.html

Friday, August 14, 2015

Carcass Management During a Mass Animal Health Emergency Draft Programmatic Environmental Impact Statement—August 2015

http://transmissiblespongiformencephalopathy.blogspot.com/2015/08/carcass-management-during-mass-animal.html

Wednesday, November 09, 2016

Chronic Wasting Disease (CWD) Program Standards - Review and Comment By Terry S Singeltary Sr. November 9, 2016

http://chronic-wasting-disease.blogspot.com/2016/11/chronic-wasting-disease-cwd-program_9.html

***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.***

http://www.nature.com/articles/srep11573

***at present, no cervid PrP allele conferring absolute resistance to prion infection has been identified.

P-145 Estimating chronic wasting disease resistance in cervids using real time quaking- induced conversion

Nicholas J Haley1, Rachel Rielinqer2, Kristen A Davenport3, W. David Walter4, Katherine I O'Rourke5, Gordon Mitchell6, Juergen A Richt2

1 Department of Microbiology and Immunology, Midwestern University, United States; 2Department of Diagnostic Medicine and Pathobiology, Kansas State University; 3Prion Research Center; Colorado State University; 4U.S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit; 5Agricultural Research Service, United States Department of Agriculture; 6Canadian Food Inspection Agency, National and OlE Reference Laboratory for Scrapie and CWD

In mammalian species, the susceptibility to prion diseases is affected, in part, by the sequence of the host's prion protein (PrP). In sheep, a gradation from scrapie susceptible to resistant has been established both in vivo and in vitro based on the amino acids present at PrP positions 136, 154, and 171, which has led to global breeding programs to reduce the prevalence of scrapie in domestic sheep. In cervids, resistance is commonly characterized as a delayed progression of chronic wasting disease (CWD); at present, no cervid PrP allele conferring absolute resistance to prion infection has been identified. To model the susceptibility of various naturally-occurring and hypothetical cervid PrP alleles in vitro, we compared the amplification rates and efficiency of various CWD isolates in recombinant PrPC using real time quaking-induced conversion. We hypothesized that amplification metrics of these isolates in cervid PrP substrates would correlate to in vivo susceptibility - allowing susceptibility prediction for alleles found at 10 frequency in nature, and that there would be an additive effect of multiple resistant codons in hypothetical alleles. Our studies demonstrate that in vitro amplification metrics predict in vivo susceptibility, and that alleles with multiple codons, each influencing resistance independently, do not necessarily contribute additively to resistance. Importantly, we found that the white-tailed deer 226K substrate exhibited the slowest amplification rate among those evaluated, suggesting that further investigation of this allele and its resistance in vivo are warranted to determine if absolute resistance to CWD is possible.

***at present, no cervid PrP allele conferring absolute resistance to prion infection has been identified.

PRION 2016 CONFERENCE TOKYO

http://prion2016.org/dl/newsletter_03.pdf

PRION 2016 TOKYO

Zoonotic Potential of CWD Prions: An Update

Ignazio Cali1, Liuting Qing1, Jue Yuan1, Shenghai Huang2, Diane Kofskey1,3, Nicholas Maurer1, Debbie McKenzie4, Jiri Safar1,3,5, Wenquan Zou1,3,5,6, Pierluigi Gambetti1, Qingzhong Kong1,5,6 1Department of Pathology, 3National Prion Disease Pathology Surveillance Center, 5Department of Neurology, 6National Center for Regenerative Medicine, Case Western Reserve University, Cleveland, OH 44106, USA. 4Department of Biological Sciences and Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada, 2Encore Health Resources, 1331 Lamar St, Houston, TX 77010

Chronic wasting disease (CWD) is a widespread and highly transmissible prion disease in free-ranging and captive cervid species in North America. The zoonotic potential of CWD prions is a serious public health concern, but the susceptibility of human CNS and peripheral organs to CWD prions remains largely unresolved. We reported earlier that peripheral and CNS infections were detected in transgenic mice expressing human PrP129M or PrP129V. Here we will present an update on this project, including evidence for strain dependence and influence of cervid PrP polymorphisms on CWD zoonosis as well as the characteristics of experimental human CWD prions.

PRION 2016 TOKYO In Conjunction with Asia Pacific Prion Symposium 2016 PRION 2016 Tokyo Prion 2016

http://prion2016.org/dl/newsletter_03.pdf

Prion 2016 Purchase options Price * Issue Purchase USD 198.00

http://www.tandfonline.com/toc/kprn20/10/sup1

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 # 1R01NS088604-01A1

Application # 9037884

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 2015-09-30

Budget End 2016-07-31

Support Year 1

Fiscal Year 2015

Total Cost $337,507

Indirect Cost $118,756

Institution

Name Case Western Reserve University

Department Pathology

Type Schools of Medicine

DUNS # 077758407

City Cleveland

State OH

Country United States

Zip Code 44106

http://grantome.com/grant/NIH/R01-NS088604-01A1

===========================================================

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.

============================================================

Key Molecular Mechanisms of TSEs

Zabel, Mark D.

Colorado State University-Fort Collins, Fort Collins, CO, United States

Abstract

Prion diseases, or transmissible spongiform encephalopathies (TSEs), are fatal neurodegenerative diseases affecting humans, cervids, bovids, and ovids. The absolute requirement of PrPC expression to generate prion diseases and the lack of instructional nucleic acid define prions as unique infectious agents. Prions exhibit species-specific tropism, inferring that unique prion strains exist that preferentially infct certain host species and confront transmission barriers to heterologous host species. However, transmission barriers are not absolute. Scientific consensus agrees that the sheep TSE scrapie probably breached the transmission barrier to cattle causing bovine spongiform encephalopathy that subsequently breached the human transmission barrier and likely caused several hundred deaths by a new-variant form of the human TSE Creutzfeldt-Jakob disease in the UK and Europe. The impact to human health, emotion and economies can still be felt in areas like farming, blood and organ donations and the threat of a latent TSE epidemic. This precedent raises the real possibility of other TSEs, like chronic wasting disease of cervids, overcoming similar human transmission barriers. A groundbreaking discovery made last year revealed that mice infected with heterologous prion strains facing significant transmission barriers replicated prions far more readily in spleens than brains6. Furthermore, these splenic prions exhibited weakened transmission barriers and expanded host ranges compared to neurogenic prions. These data question conventional wisdom of avoiding neural tissue to avoid prion xenotransmission, when more promiscuous prions may lurk in extraneural tissues. Data derived from work previously funded by NIH demonstrate that Complement receptors CD21/35 bind prions and high density PrPC and differentially impact prion disease depending on the prion isolate or strain used. Recent advances in live animal and whole organ imaging have led us to generate preliminary data to support novel, innovative approaches to assessing prion capture and transport. We plan to test our unifying hypothesis for this proposal that CD21/35 control the processes of peripheral prion capture, transport, strain selection and xenotransmission in the following specific aims. 1. Assess the role of CD21/35 in splenic prion strain selection and host range expansion. 2. Determine whether CD21/35 and C1q differentially bind distinct prion strains 3. Monitor the effects of CD21/35 on prion trafficking in real time and space 4. Assess the role of CD21/35 in incunabular prion trafficking

Public Health Relevance Transmissible spongiform encephalopathies, or prion diseases, are devastating illnesses that greatly impact public health, agriculture and wildlife in North America and around the world. The impact to human health, emotion and economies can still be felt in areas like farming, blood and organ donations and the threat of a latent TSE epidemic. This precedent raises the real possibility of other TSEs, like chronic wasting disease (CWD) of cervids, overcoming similar human transmission barriers. Early this year Canada reported its first case of BSE in over a decade audits first case of CWD in farmed elk in three years, underscoring the need for continued vigilance and research. Identifying mechanisms of transmission and zoonoses remains an extremely important and intense area of research that will benefit human and other animal populations.

Funding Agency Agency National Institute of Health (NIH)

Institute National Institute of Allergy and Infectious Diseases (NIAID)

Type High Priority, Short Term Project Award (R56)

Project # 1R56AI122273-01A1

Application # 9211114

Study Section Cellular and Molecular Biology of Neurodegeneration Study Section (CMND)

Program Officer Beisel, Christopher E

Project Start 2016-02-16

Project End 2017-01-31

Budget Start 2016-02-16

Budget End 2017-01-31

Support Year 1

Fiscal Year 2016

Total Cost

Indirect Cost Institution Name Colorado State University-Fort Collins

Department Microbiology/Immun/Virology

Type Schools of Veterinary Medicine

DUNS # 785979618 City Fort Collins

State CO

Country United States

Zip Code 80523

http://grantome.com/grant/NIH/R56-AI122273-01A1

PMCA Detection of CWD Infection in Cervid and Non-Cervid Species

Hoover, Edward Arthur

Colorado State University-Fort Collins, Fort Collins, CO, United States

Abstract

Chronic wasting disease (CWD) of deer and elk is an emerging highly transmissible prion disease now recognized in 18 States, 2 Canadian provinces, and Korea. We have shown that Infected deer harbor and shed high levels of infectious prions in saliva, blood, urine, and feces, and in the tissues generating those body fluids and excreta, thereby leading to facile transmission by direct contact and environmental contamination. We have also shown that CWD can infect some non-cervid species, thus the potential risk CWD represents to domestic animal species and to humans remains unknown. Whether prions borne in blood, saliva, nasal fluids, milk, or excreta are generated or modified in the proximate peripheral tissue sites, may differ in subtle ways from those generated in brain, or may be adapted for mucosal infection remain open questions. The increasing parallels in the pathogenesis between prion diseases and human neurodegenerative conditions, such as Alzheimer's and Parkinson's diseases, add relevance to CWD as a transmissible protein misfolding disease. The overall goal of this work is to elucidate the process of CWD prion transmission from mucosal secretory and excretory tissue sites by addressing these questions: (a) What are the kinetics and magnitude of CWD prion shedding post-exposure? (b) Are excreted prions biochemically distinct, or not, from those in the CNS? (c) Are peripheral epithelial or CNS tissues, or both, the source of excreted prions? and (d) Are excreted prions adapted for horizontal transmission via natural/trans-mucosal routes? The specific aims of this proposal are: (1) To determine the onset and consistency of CWD prion shedding in deer and cervidized mice; (2); To compare the biochemical and biophysical properties of excretory vs. CNS prions; (3) To determine the capacity of peripheral tissues to support replication of CWD prions; (4) To determine the protease- sensitive infectious fraction of excreted vs. CNS prions; and (5) To compare the mucosal infectivity of excretory vs. CNS prions. Understanding the mechanisms that enable efficient prion dissemination and shedding will help elucidate how horizontally transmissible prions evolve and succeed, and is the basis of this proposal. Understanding how infectious misfolded proteins (prions) are generated, trafficked, shed, and transmitted will aid in preventing, treating, and managing the risks associated with these agents and the diseases they cause.

Public Health Relevance Chronic wasting disease (CWD) of deer and elk is an emergent highly transmissible prion disease now recognized throughout the USA as well as in Canada and Korea. We have shown that infected deer harbor and shed high levels of infectious prions in saliva, blood, urine, and feces thereby leading to transmission by direct contact and environmental contamination. In that our studies have also shown that CWD can infect some non-cervid species, the potential risk CWD may represents to domestic animal species and humans remains unknown. The increasing parallels in the development of major human neurodegenerative conditions, such as Alzheimer's and Parkinson's diseases, and prion diseases add relevance to CWD as a model of a transmissible protein misfolding disease. Understanding how infectious misfolded proteins (prions) are generated and transmitted will aid in interrupting, treating, and managing the risks associated with these agents and the diseases they cause.

Funding Agency Agency National Institute of Health (NIH)

Institute National Institute of Neurological Disorders and Stroke (NINDS)

Type Research Project (R01)

Project # 4R01NS061902-07

Application # 9010980

Study Section Cellular and Molecular Biology of Neurodegeneration Study Section (CMND)

Program Officer Wong, May Project Start 2009-09-30

Project End 2018-02-28

Budget Start 2016-03-01

Budget End 2017-02-28

Support Year 7

Fiscal Year 2016

Total Cost $409,868

Indirect Cost $134,234 Institution Name Colorado State University-Fort Collins

Department Microbiology/Immun/Virology

Type Schools of Veterinary Medicine

DUNS # 785979618 City Fort Collins

State CO

Country United States

Zip Code 80523

http://grantome.com/grant/NIH/R01-NS061902-07

LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$

*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***

https://www.landesbioscience.com/journals/prion/article/28124/?nocache=112223249

PRION 2015 CONFERENCE FT. COLLINS CWD RISK FACTORS TO HUMANS

*** LATE-BREAKING ABSTRACTS PRION 2015 CONFERENCE ***

O18

Zoonotic Potential of CWD Prions

Liuting Qing1, Ignazio Cali1,2, Jue Yuan1, Shenghai Huang3, Diane Kofskey1, Pierluigi Gambetti1, Wenquan Zou1, Qingzhong Kong1 1Case Western Reserve University, Cleveland, Ohio, USA, 2Second University of Naples, Naples, Italy, 3Encore Health Resources, Houston, Texas, USA

*** These results indicate that the CWD prion has the potential to infect human CNS and peripheral lymphoid tissues and that there might be asymptomatic human carriers of CWD infection.

==================

***These results indicate that the CWD prion has the potential to infect human CNS and peripheral lymphoid tissues and that there might be asymptomatic human carriers of CWD infection.***

==================

P.105: RT-QuIC models trans-species prion transmission

Kristen Davenport, Davin Henderson, Candace Mathiason, and Edward Hoover Prion Research Center; Colorado State University; Fort Collins, CO USA

Conversely, FSE maintained sufficient BSE characteristics to more efficiently convert bovine rPrP than feline rPrP. Additionally, human rPrP was competent for conversion by CWD and fCWD.

***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.

================

***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.***

================

https://prion2015.files.wordpress.com/2015/05/programguide1.pdf

*** PRICE OF CWD TSE PRION POKER GOES UP 2014 ***

Transmissible Spongiform Encephalopathy TSE PRION update January 2, 2014

*** chronic wasting disease, there was no absolute barrier to conversion of the human prion protein.

*** 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.

http://wwwnc.cdc.gov/eid/article/20/1/13-0858_article.htm

http://chronic-wasting-disease.blogspot.com/2014/01/molecular-barriers-to-zoonotic.html

*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***

https://www.landesbioscience.com/journals/prion/article/28124/?nocache=112223249

*** 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.

http://cdmrp.army.mil/prevfunded/nprp/NPRP_Summit_Final_Report.pdf

***********CJD REPORT 1994 increased risk for consumption of veal and venison and lamb***********

CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994

Consumption of venison and veal was much less widespread among both cases and controls. For both of these meats there was evidence of a trend with increasing frequency of consumption being associated with increasing risk of CJD. (not nvCJD, but sporadic CJD...tss)

These associations were largely unchanged when attention was restricted to pairs with data obtained from relatives. ...

Table 9 presents the results of an analysis of these data.

There is STRONG evidence of an association between ‘’regular’’ veal eating and risk of CJD (p = .0.01).

Individuals reported to eat veal on average at least once a year appear to be at 13 TIMES THE RISK of individuals who have never eaten veal.

There is, however, a very wide confidence interval around this estimate. There is no strong evidence that eating veal less than once per year is associated with increased risk of CJD (p = 0.51).

The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).

There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02).

The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).

snip...

It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).

snip...

In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...

snip...

In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)

snip...see full report ;

http://collections.europarchive.org/tna/20090505194948/http://bseinquiry.gov.uk/files/yb/1994/08/00004001.pdf

CJD9/10022

October 1994

Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane BerksWell Coventry CV7 7BZ

Dear Mr Elmhirst,

CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT

Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.

The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.

The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.

The statistical results reqarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.

I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.

http://web.archive.org/web/20030511010117/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf

Monday, May 02, 2016

*** Zoonotic Potential of CWD Prions: An Update Prion 2016 Tokyo ***

http://chronic-wasting-disease.blogspot.com/2016/05/zoonotic-potential-of-cwd-prions-update.html

*** PRION 2014 CONFERENCE CHRONIC WASTING DISEASE CWD

http://chronic-wasting-disease.blogspot.com/2014/06/prion-2014-chronic-wasting-disease-cwd.html

http://chronic-wasting-disease.blogspot.com/2016/07/colorado-chronic-wasting-disease-cwd.html

http://chronic-wasting-disease.blogspot.com/

Monday, May 02, 2016

*** Zoonotic Potential of CWD Prions: An Update Prion 2016 Tokyo ***

http://chronic-wasting-disease.blogspot.com/2016/05/zoonotic-potential-of-cwd-prions-update.html

Saturday, April 23, 2016

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 ef?ciency comparable to that of cattle BSE. While the ef?ciency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice. Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion. These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.

http://www.tandfonline.com/na101/home/literatum/publisher/tandf/journals/content/kprn20/2016/kprn20.v010.sup01/19336896.2016.1163048/20160418/19336896.2016.1163048.fp.png_v03

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

http://collections.europarchive.org/tna/20080102222950/http://www.bseinquiry.gov.uk/files/yb/1990/09/23001001.pdf

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

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

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

http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160

O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations

Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France

Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases). Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.

*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,

***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),

***is the third potentially zoonotic PD (with BSE and L-type BSE),

***thus questioning the origin of human sporadic cases. We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.

===============

***thus questioning the origin of human sporadic cases***

===============

***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.

==============

https://prion2015.files.wordpress.com/2015/05/prion2015abstracts.pdf

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

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

http://scrapie-usa.blogspot.com/2016/04/scrapie-ws-01-prion-diseases-in-animals.html

***This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated. Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.

http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160

please see file attachment for full submission and recent science and my deep concerns on the TSE Prion disease... No documents available. AttachmentsView All (1) scrapie-usa-blogspot-com View Attachment:

http://www.regulations.gov/#!documentDetail;D=APHIS-2007-0127-0032

Saturday, November 12, 2016

Maine Medical Center received confirmation patient treated at the hospital has Creutzfeldt-Jakob disease

http://creutzfeldt-jakob-disease.blogspot.com/2016/11/maine-medical-center-received.html

Terry S. Singeltary Sr.