Wednesday, July 29, 2015

Progressive accumulation of the abnormal conformer of the prion protein and spongiform encephalopathy in the obex of nonsymptomatic and symptomatic Rocky Mountain elk (Cervus elaphus nelsoni) with chronic wasting disease

Progressive accumulation of the abnormal conformer of the prion protein and spongiform encephalopathy in the obex of nonsymptomatic and symptomatic Rocky Mountain elk (Cervus elaphus nelsoni) with chronic wasting disease

 

Terry R. Spraker1 Thomas Gidlewski Jenny G. Powers Tracy Nichols Aru Balachandran Bruce Cummings Margaret A. Wild Kurt VerCauteren Katherine I. O’Rourke Colorado State University Diagnostic Laboratory, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO (Spraker, Cummings) National Wildlife Research Center, U.S. Department of Agriculture (USDA), Animal and Plant Health Inspection Service, Wildlife Services, Fort Collins, CO (Gidlewski, Nichols, VerCauteren) National Park Service, Biological Resources Management Division, Fort Collins, CO (Powers, Wild) Canadian Food Inspection Services, Ottawa, Ontario, Canada (Balachandran) USDA, Agricultural Research Service, Pullman, WA (O’Rourke) ↵1Terry R. Spraker, Colorado State University Diagnostic Laboratory, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins CO 80526. terry.spraker@colostate.edu Next Section Abstract The purpose of our study was to describe the progressive accumulation of the abnormal conformer of the prion protein (PrPCWD) and spongiform degeneration in a single section of brain stem in Rocky Mountain elk (Cervus elaphus nelsoni) with chronic wasting disease (CWD). A section of obex from 85 CWD-positive elk was scored using the presence and abundance of PrPCWD immunoreactivity and spongiform degeneration in 10 nuclear regions and the presence and abundance of PrPCWD in 10 axonal tracts, the subependymal area of the fourth ventricle, and the thin subpial astrocytic layer (glial limitans). Data was placed in a formula to generate an overall obex score. Data suggests that PrPCWD immunoreactivity and spongiform degeneration has a unique and relatively consistent pattern of progression throughout a section of obex. This scoring technique utilizing a single section of obex may prove useful in future work for estimating the presence and abundance of PrPCWD in peripheral tissues and the nervous system in elk with CWD.

 

Chronic wasting disease elk, obex prion protein spongiform encephalopathy.

 


 

ATYPICAL LESION DISTRIBUTION (RBSE 92/21367)

 

A 6 year old, home bred (HB), Friesian x Holstein cow in a dairy herd in Aberdeenshirer submitted as a suspect BSE case in the negative study (SE0203), has been diagnosed as BSE negative on standard, statutory (obex only), diagnostic criteria at CVL.

 

Further examination by Dr Jeffrey at Lasswade, as required by the project design, has revealed vacuolar change in the septal nucleus and putamen which co-localised with PrP immunoreactivity. No significant lesions were found in any other part of the brain, neither was PrP found in the medulla.

 

It is important to note that examination of four brain blocks used earlier in the epidemic would not have detected the lesion but a 16 block study (as used in the very days of BSE) would.

 

FURTHER INFORMATION

 

The herd of origin has had 15, HB, suspect cases of BSE since July 1989 and a further case is still alive.

 

2. Of the 15, eight have been confirmed by standard histopathology and seven diagnosed negative (including the above case).

 

3. Fixed brain tissue from the negative cases exists at Lasswade (because they always collect whole brain in Scotland) but has not so far been examined further. No frozen tissue was collected so neither SAF nor PrP detection (by immunoblotting) has been attempted.

 

4. Mr Wells agrees with Dr Jeffrey's and Dr Simmons' findings.

 

FURTHER ACTION IN PROGRESS

 

1. The brain tissue from the negative cases will be examined in detail by conventional histopathology and ICC.

 

2. Kevin Taylor and his veterinary colleagues have been alerted to the situation.

 

OTHER RECOMMENDED ACTIONS

 

1. TRANSMISSION Attempt transmission from the 'case' to standard mice strains. (Note: In regard to strain typing, formalin may have modified strain phenotype - we need to discuss with NPU). Further transmission studies (eg in cattle) might be suggested if primary transmission in mice fails. These proposals have funding implications.

 

CODE 18-77

 

93/2.17/1.1

 

2. PrP GENOTYPING - Although only fixed brain tissue is available we are considering genotyping from parents/offspring/fixed brain. As a first step we are attempting to extract DNA from the fixed brain and to amplify the PrP gene by PCR.

 

3. John Wilesmith has interrogated the data base for the herd history. Other than the high proportion of negative cases nothing significant is apparent.

 

4. Familial relationships between suspect (including positive and negative) cases in this herd could be examined and tracings of breeding animals initiated.

 

5. Consideration might be given to collecting frozen spinal cord from new cases in this herd or in dispersals from it for (SAF/PrP examination).

 

CONCLUSIONS

 

1. At present it is unclear whether or not this is a singleton incident or whether the other negative cases in this herd show a similar lesion.

 

2. The discovery might indicate the existence of a different strain of BSE from that present in the general epidemic or an unusual response by an individual host.

 

3. If further atypical lesion distribution cases are revealed in this herd then implications of misdiagnosis of 'negative' cases in other herds may not be insignificant.

 

4. If this is a new strain all the implications need to be considered including whether or not to proceed with the further investigation of future cases negative for BSE on obex examination alone and from which whole brains are available (as in Scotland) or collected in the future. Also perhaps investigation of the tissue distribution of infectivity in these animals might be considered.

 

5. Animal and public health controls in place should be sufficient since all tissues (other than brain for diagnosis) are incinerated.

 

We observe that Dr Tyrrell would wish to be informed of this at an early opportunity and that the SEAC would wish to discuss it at their meeting in April.

 

R BRADLEY

 

M DAWSON

 

17 February 1993

 

CVO - for information and comment on further action please

 

cc Mr K C Taylor

 

Dr B J Shreeve

 

93/2.17/1.2

 

This minute is re-issued with a wider distribution.

 

The information contained herein should not be disseminated further except on the basis of "NEED TO KNOW".

 

Mr Scudamore

 

Mr R C Lowson

 

Dr D Matthews

 

Mr I Robertson

 

Dr K MacOwan

 

Mr C Randall

 

Mr J W Wilesmith

 

Mr G A H Wells

 

Dr M Jeffrey

 

Dr M Simmons

 

93/2.17/1.3

 


 

IN CONFIDENCE

 

BSE - ATYPICAL LESION DISTRIBUTION (RBSE 92-21367)

 


 

1992

 

NEW BRAIN DISORDER

 

3. WHAT ABOUT REPORTS OF NEW FORM OF BSE ?

 

THE VETERINARY RECORD HAS PUBLISHED AN ARTICLE ON A NEW BRAIN DISORDER OF CATTLE DISCOVERED THROUGH OUR CONTROL MEASURES FOR BSE. ALTHOUGH IT PRESENTS SIMILAR CLINICAL SIGNS TO BSE THERE ARE MAJOR DIFFERENCES IN HISTOPATHOLOGY AND INCUBATION PERIODS BETWEEN THE TWO. MUST EMPHASISE THAT THIS IS _NOT_ BSE.

 

4. IS THIS NEW BRAIN DISORDER A THREAT ?

 

WE DO NOT EVEN KNOW WHETHER THE AGENT OF THIS DISEASE IS TRANSMISSIBLE. IN ANY CASE, CASES SO FAR IDENTIFIED HAD SHOWN SIMILAR SYMPTOMS TO THOSE OF BSE, AND THEREFORE HAVE BEEN SLAUGHTERED AND INCINERATED, SO THAT IF A TRANSMISSIBLE AGENT WERE INVOLVED IT WOULD HAVE BEEN ELIMINATED. ...

 


 

PLEASE NOTE *

 

Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.

 

snip...

 

The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...

 


 

AND THE USDA ET AL KNEW IT TOO ;

 

"These 9,200 cases were different because brain tissue samples were preserved with formalin, which makes them suitable for only one type of test--immunohistochemistry, or IHC."

 

THIS WAS DONE FOR A REASON!

 

THE IHC test has been proven to be the LEAST LIKELY to detect BSE/TSE in the bovine, and these were probably from the most high risk cattle pool, the ones the USDA et al, SHOULD have been testing. ...TSS

 

USDA 2003

 

We have to be careful that we don't get so set in the way we do things that we forget to look for different emerging variations of disease. We've gotten away from collecting the whole brain in our systems. We're using the brain stem and we're looking in only one area. In Norway, they were doing a project and looking at cases of Scrapie, and they found this where they did not find lesions or PRP in the area of the obex. They found it in the cerebellum and the cerebrum. It's a good lesson for us. Ames had to go back and change the procedure for looking at Scrapie samples. In the USDA, we had routinely looked at all the sections of the brain, and then we got away from it. They've recently gone back. Dr. Keller: Tissues are routinely tested, based on which tissue provides an 'official' test result as recognized by APHIS.

 

Dr. Detwiler: That's on the slaughter. But on the clinical cases, aren't they still asking for the brain? But even on the slaughter, they're looking only at the brainstem. We may be missing certain things if we confine ourselves to one area.

 

snip.............

 

Dr. Detwiler: It seems a good idea, but I'm not aware of it. Another important thing to get across to the public is that the negatives do not guarantee absence of infectivity. The animal could be early in the disease and the incubation period. Even sample collection is so important. If you're not collecting the right area of the brain in sheep, or if collecting lymphoreticular tissue, and you don't get a good biopsy, you could miss the area with the PRP in it and come up with a negative test. There's a new, unusual form of Scrapie that's been detected in Norway. We have to be careful that we don't get so set in the way we do things that we forget to look for different emerging variations of disease. We've gotten away from collecting the whole brain in our systems. We're using the brain stem and we're looking in only one area. In Norway, they were doing a project and looking at cases of Scrapie, and they found this where they did not find lesions or PRP in the area of the obex. They found it in the cerebellum and the cerebrum. It's a good lesson for us. Ames had to go back and change the procedure for looking at Scrapie samples. In the USDA, we had routinely looked at all the sections of the brain, and then we got away from it. They've recently gone back.

 

Dr. Keller: Tissues are routinely tested, based on which tissue provides an 'official' test result as recognized by APHIS .

 

Dr. Detwiler: That's on the slaughter. But on the clinical cases, aren't they still asking for the brain? But even on the slaughter, they're looking only at the brainstem. We may be missing certain things if we confine ourselves to one area.

 

snip...

 

FULL TEXT;

 

Completely Edited Version PRION ROUNDTABLE

 

Accomplished this day, Wednesday, December 11, 2003, Denver, Colorado

 

END...TSS

 

==========

 

Subject: USDA OIG SEMIANNUAL REPORT TO CONGRESS FY 2007 1st Half (bogus BSE sampling FROM HEALTHY USDA CATTLE)

 

Date: June 21, 2007 at 2:49 pm PST

 

Owner and Corporation Plead Guilty to Defrauding Bovine Spongiform Encephalopathy (BSE) Surveillance Program

 

An Arizona meat processing company and its owner pled guilty in February 2007 to charges of theft of Government funds, mail fraud, and wire fraud. The owner and his company defrauded the BSE Surveillance Program when they falsified BSE Surveillance Data Collection Forms and then submitted payment requests to USDA for the services. In addition to the targeted sample population (those cattle that were more than 30 months old or had other risk factors for BSE), the owner submitted to USDA, or caused to be submitted, BSE obex (brain stem) samples from healthy USDA-inspected cattle. As a result, the owner fraudulently received approximately $390,000. Sentencing is scheduled for May 2007.

 

snip...

 

Topics that will be covered in ongoing or planned reviews under Goal 1 include:

 

soundness of BSE maintenance sampling (APHIS),

 

implementation of Performance-Based Inspection System enhancements for specified risk material (SRM) violations and improved inspection controls over SRMs (FSIS and APHIS),

 

snip...

 

The findings and recommendations from these efforts will be covered in future semiannual reports as the relevant audits and investigations are completed.

 

4 USDA OIG SEMIANNUAL REPORT TO CONGRESS FY 2007 1st Half

 


 

Wednesday, July 15, 2015

 

Additional BSE TSE prion testing detects pathologic lesion in unusual brain location and PrPsc by PMCA only, how many cases have we missed?

 


 

***however in 1 C-type challenged animal, Prion 2015 Poster Abstracts S67 PrPsc was not detected using rapid tests for BSE.

 

***Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.

 

IBNC Tauopathy or TSE Prion disease, it appears, no one is sure

 

Posted by flounder on 03 Jul 2015 at 16:53 GMT

 


 

HOUND STUDY

 

AS implied in the Inset 25 we must not _ASSUME_ that transmission of BSE to other species will invariably present pathology typical of a scrapie-like disease.

 

snip...

 


 

DEFRA Department for Environment, Food & Rural Affairs

 

Area 307, London, SW1P 4PQ Telephone: 0207 904 6000 Direct line: 0207 904 6287 E-mail: h.mcdonagh.defra.gsi.gov.uk

 

GTN: FAX:

 

Mr T S Singeltary P.O. Box 42 Bacliff Texas USA 77518

 

21 November 2001

 

Dear Mr Singeltary

 

TSE IN HOUNDS

 

Thank you for e-mail regarding the hounds survey. I am sorry for the long delay in responding.

 

As you note, the hound survey remains unpublished. However the Spongiform Encephalopathy Advisory Committee (SEAC), the UK Government's independent Advisory Committee on all aspects related to BSE-like disease, gave the hound study detailed consideration at their meeting in January 1994. As a summary of this meeting published in the BSE inquiry noted, the Committee were clearly concerned about the work that had been carried out, concluding that there had clearly been problems with it, particularly the control on the histology, and that it was more or less inconclusive. However was agreed that there should be a re-evaluation of the pathological material in the study.

 

Later, at their meeting in June 95, The Committee re-evaluated the hound study to see if any useful results could be gained from it. The Chairman concluded that there were varying opinions within the Committee on further work. It did not suggest any further transmission studies and thought that the lack of clinical data was a major weakness.

 

Overall, it is clear that SEAC had major concerns about the survey as conducted. As a result it is likely that the authors felt that it would not stand up to r~eer review and hence it was never published. As noted above, and in the detailed minutes of the SEAC meeting in June 95, SEAC considered whether additional work should be performed to examine dogs for evidence of TSE infection. Although the Committee had mixed views about the merits of conducting further work, the Chairman noted that when the Southwood Committee made their recommendation to complete an assessment of possible spongiform disease in dogs, no TSEs had been identified in other species and hence dogs were perceived as a high risk population and worthy of study. However subsequent to the original recommendation, made in 1990, a number of other species had been identified with TSE ( e.g. cats) so a study in hounds was less

 

critical. For more details see- http://www.bseinquiry, gov.uk/files/yb/1995/06/21005001 .pdf

 

As this study remains unpublished, my understanding is that the ownership of the data essentially remains with the original researchers. Thus unfortunately, I am unable to help with your request to supply information on the hound survey directly. My only suggestion is that you contact one of the researchers originally involved in the project, such as Gerald Wells. He can be contacted at the following address.

 

Dr Gerald Wells, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey, KT 15 3NB, UK

 

You may also wish to be aware that since November 1994 all suspected cases of spongiform encephalopathy in animals and poultry were made notifiable. Hence since that date there has been a requirement for vets to report any suspect SE in dogs for further investigation. To date there has never been positive identification of a TSE in a dog.

 

I hope this is helpful

 

Yours sincerely 4

 

HUGH MCDONAGH BSE CORRESPONDENCE SECTION

 

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

 

OR-09: Canine spongiform encephalopathy—A new form of animal prion disease

 

Monique David, Mourad Tayebi UT Health; Houston, TX USA

 

It was also hypothesized that BSE might have originated from an unrecognized sporadic or genetic case of bovine prion disease incorporated into cattle feed or even cattle feed contaminated with prion-infected human remains.1 However, strong support for a genetic origin of BSE has recently been demonstrated in an H-type BSE case exhibiting the novel mutation E211K.2 Furthermore, a specific prion protein strain causing BSE in cattle is believed to be the etiological agent responsible for the novel human prion disease, variant Creutzfeldt-Jakob disease (vCJD).3 Cases of vCJD have been identified in a number countries, including France, Italy, Ireland, the Netherlands, Canada, Japan, US and the UK with the largest number of cases. Naturally occurring feline spongiform encephalopathy of domestic cats4 and spongiform encephalopathies of a number of zoo animals so-called exotic ungulate encephalopathies5,6 are also recognized as animal prion diseases, and are thought to have resulted from the same BSE-contaminated food given to cattle and humans, although and at least in some of these cases, a sporadic and/or genetic etiology cannot be ruled out. The canine species seems to display resistance to prion disease and no single case has so far been reported.7,8 Here, we describe a case of a 9 week old male Rottweiler puppy presenting neurological deficits; and histological examination revealed spongiform vacuolation characteristic of those associated with prion diseases.9 Initial biochemical studies using anti-PrP antibodies revealed the presence of partially proteinase K-resistant fragment by western blotting. Furthermore, immunohistochemistry revealed spongiform degeneration consistent with those found in prion disease and displayed staining for PrPSc in the cortex.

 

Of major importance, PrPSc isolated from the Rottweiler was able to cross the species barrier transmitted to hamster in vitro with PMCA and in vivo (one hamster out of 5). Futhermore, second in vivo passage to hamsters, led to 100% attack rate (n = 4) and animals displayed untypical lesional profile and shorter incubation period.

 

In this study, we show that the canine species might be sensitive to prion disease and that PrPSc isolated from a dog can be transmitted to dogs and hamsters in vitro using PMCA and in vivo to hamsters.

 

If our preliminary results are confirmed, the proposal will have a major impact on animal and public health and would certainly lead to implementing new control measures for ‘canine spongiform encephalopathy’ (CSE).

 

References 1. Colchester AC, Colchester NT. The origin of bovine spongiform encephalopathy: the human prion disease hypothesis. Lancet 2005; 366:856-61; PMID:16139661; http:// dx.doi.org/10.1016/S0140-6736(05)67218-2.

 

2. Richt JA, Hall SM. BSE case associated with prion protein gene mutation. PLoS Pathog 2008; 4:e1000156; PMID:18787697; http://dx.doi.org/10.1371/journal. ppat.1000156.

 

3. Collinge J. Human prion diseases and bovine spongiform encephalopathy (BSE). Hum Mol Genet 1997; 6:1699-705; PMID:9300662; http://dx.doi.org/10.1093/ hmg/6.10.1699.

 

4. Wyatt JM, Pearson GR, Smerdon TN, Gruffydd-Jones TJ, Wells GA, Wilesmith JW. Naturally occurring scrapie-like spongiform encephalopathy in five domestic cats. Vet Rec 1991; 129:233-6; PMID:1957458; http://dx.doi.org/10.1136/vr.129.11.233.

 

5. Jeffrey M, Wells GA. Spongiform encephalopathy in a nyala (Tragelaphus angasi). Vet Pathol 1988; 25:398-9; PMID:3232315; http://dx.doi.org/10.1177/030098588802500514.

 

6. Kirkwood JK, Wells GA, Wilesmith JW, Cunningham AA, Jackson SI. Spongiform encephalopathy in an arabian oryx (Oryx leucoryx) and a greater kudu (Tragelaphus strepsiceros). Vet Rec 1990; 127:418-20; PMID:2264242.

 

7. Bartz JC, McKenzie DI, Bessen RA, Marsh RF, Aiken JM. Transmissible mink encephalopathy species barrier effect between ferret and mink: PrP gene and protein analysis. J Gen Virol 1994; 75:2947-53; PMID:7964604; http://dx.doi.org/10.1099/0022-1317- 75-11-2947.

 

8. Lysek DA, Schorn C, Nivon LG, Esteve-Moya V, Christen B, Calzolai L, et al. Prion protein NMR structures of cats, dogs, pigs, and sheep. Proc Natl Acad Sci U S A 2005; 102:640-5; PMID:15647367; http://dx.doi.org/10.1073/pnas.0408937102.

 

9. Budka H. Neuropathology of prion diseases. Br Med Bull 2003; 66:121-30; PMID:14522854; http://dx.doi.org/10.1093/bmb/66.1.121.

 


 

Monday, March 26, 2012

 

CANINE SPONGIFORM ENCEPHALOPATHY: A NEW FORM OF ANIMAL PRION DISEASE

 


 

Monday, March 8, 2010

 

Canine Spongiform Encephalopathy aka MAD DOG DISEASE

 


 

Wednesday, July 29, 2015

 

Porcine Prion Protein Amyloid or mad pig disease PSE

 


 

Friday, January 30, 2015

 

*** Scrapie: a particularly persistent pathogen ***

 


 

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

 

The propensity for trans-species prion transmission is related to the structural characteristics of the enciphering and heterologous PrP, but the exact mechanism remains mostly mysterious. Studies of the effects of primary or tertiary prion protein structures on trans-species prion transmission have relied primarily upon animal bioassays, making the influence of prion protein structure vs. host co-factors (e.g. cellular constituents, trafficking, and innate immune interactions) difficult to dissect. As an alternative strategy, we used real-time quakinginduced conversion (RT-QuIC) to investigate trans-species prion conversion.

 

To assess trans-species conversion in the RT-QuIC system, we compared chronic wasting disease (CWD) and bovine spongiform encephalopathy (BSE) prions, as well as feline CWD (fCWD) and feline spongiform encephalopathy (FSE). Each prion was seeded into each host recombinant PrP (full-length rPrP of white-tailed deer, bovine or feline). We demonstrated that fCWD is a more efficient seed for feline rPrP than for white-tailed deer rPrP, which suggests adaptation to the new host.

 

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.***

 

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

 


 

*** We hypothesize that both BSE prions and CWD prions passaged through felines will seed human recPrP more efficiently than BSE or CWD from the original hosts, evidence that the new host will dampen the species barrier between humans and BSE or CWD. The new host effect is particularly relevant as we investigate potential means of trans-species transmission of prion disease.

 


 

Monday, August 8, 2011

 

*** Susceptibility of Domestic Cats to CWD Infection ***

 

Oral.29: Susceptibility of Domestic Cats to CWD Infection

 

Amy Nalls, Nicholas J. Haley, Jeanette Hayes-Klug, Kelly Anderson, Davis M. Seelig, Dan S. Bucy, Susan L. Kraft, Edward A. Hoover and Candace K. Mathiason†

 

Colorado State University; Fort Collins, CO USA†Presenting author; Email: ckm@lamar.colostate.edu

 

Domestic and non-domestic cats have been shown to be susceptible to one prion disease, feline spongiform encephalopathy (FSE), thought to be transmitted through consumption of bovine spongiform encephalopathy (BSE) contaminated meat. Because domestic and free ranging felids scavenge cervid carcasses, including those in CWD affected areas, we evaluated the susceptibility of domestic cats to CWD infection experimentally. Groups of n = 5 cats each were inoculated either intracerebrally (IC) or orally (PO) with CWD deer brain homogenate. Between 40–43 months following IC inoculation, two cats developed mild but progressive symptoms including weight loss, anorexia, polydipsia, patterned motor behaviors and ataxia—ultimately mandating euthanasia. Magnetic resonance imaging (MRI) on the brain of one of these animals (vs. two age-matched controls) performed just before euthanasia revealed increased ventricular system volume, more prominent sulci, and T2 hyperintensity deep in the white matter of the frontal hemisphere and in cortical grey distributed through the brain, likely representing inflammation or gliosis. PrPRES and widely distributed peri-neuronal vacuoles were demonstrated in the brains of both animals by immunodetection assays. No clinical signs of TSE have been detected in the remaining primary passage cats after 80 months pi. Feline-adapted CWD was sub-passaged into groups (n=4 or 5) of cats by IC, PO, and IP/SQ routes. Currently, at 22 months pi, all five IC inoculated cats are demonstrating abnormal behavior including increasing aggressiveness, pacing, and hyper responsiveness.

 

*** Two of these cats have developed rear limb ataxia. Although the limited data from this ongoing study must be considered preliminary, they raise the potential for cervid-to-feline transmission in nature.

 


 


 

AD.63:

 

Susceptibility of domestic cats to chronic wasting disease

 

Amy V.Nalls,1 Candace Mathiason,1 Davis Seelig,2 Susan Kraft,1 Kevin Carnes,1 Kelly Anderson,1 Jeanette Hayes-Klug1 and Edward A. Hoover1 1Colorado State University; Fort Collins, CO USA; 2University of Minnesota; Saint Paul, MN USA

 

Domestic and nondomestic cats have been shown to be susceptible to feline spongiform encephalopathy (FSE), almost certainly caused by consumption of bovine spongiform encephalopathy (BSE)-contaminated meat. Because domestic and free-ranging nondomestic felids scavenge cervid carcasses, including those in areas affected by chronic wasting disease (CWD), we evaluated the susceptibility of the domestic cat (Felis catus) to CWD infection experimentally. Cohorts of 5 cats each were inoculated either intracerebrally (IC) or orally (PO) with CWD-infected deer brain. At 40 and 42 mo post-inoculation, two IC-inoculated cats developed signs consistent with prion disease, including a stilted gait, weight loss, anorexia, polydipsia, patterned motor behaviors, head and tail tremors, and ataxia, and progressed to terminal disease within 5 mo. Brains from these two cats were pooled and inoculated into cohorts of cats by IC, PO, and intraperitoneal and subcutaneous (IP/SC) routes. Upon subpassage, feline-adapted CWD (FelCWD) was transmitted to all IC-inoculated cats with a decreased incubation period of 23 to 27 mo. FelCWD was detected in the brains of all the symptomatic cats by western blotting and immunohistochemistry and abnormalities were seen in magnetic resonance imaging, including multifocal T2 fluid attenuated inversion recovery (FLAIR) signal hyper-intensities, ventricular size increases, prominent sulci, and white matter tract cavitation. Currently, 3 of 4 IP/SQ and 2 of 4 PO inoculared cats have developed abnormal behavior patterns consistent with the early stage of feline CWD.

 

*** These results demonstrate that CWD can be transmitted and adapted to the domestic cat, thus raising the issue of potential cervid-to- feline transmission in nature.

 


 

www.landesbioscience.com

 

PO-081: Chronic wasting disease in the cat— Similarities to feline spongiform encephalopathy (FSE)

 


 


 

FELINE SPONGIFORM ENCEPHALOPATHY FSE

 


 


 

Saturday, January 31, 2015

 

European red deer (Cervus elaphus elaphus) are susceptible to Bovine Spongiform Encephalopathy BSE by Oral Alimentary route

 


 

*** Singeltary reply ;

 

ruminant feed ban for cervids in the United States ?

 

31 Jan 2015 at 20:14 GMT

 


 


 


 


 


 


 


 


 


 


 


 


 

Terry S. Singeltary Sr.

Tuesday, July 28, 2015

TEXAS Kills 35 Deer at Medina County Ranch (Texas Captive CWD)

Tuesday, July 28, 2015 TEXAS Kills 35 Deer at Medina County Ranch (Texas Captive CWD)

 

 State kills 35 deer at Medina County ranch

 

 By Zeke MacCormack : July 28, 2015

 

 HONDO — The state of Texas euthanized 35 deer Tuesday at a breeding facility in Medina County so they can be tested for chronic wasting disease. An infected buck was found at the ranch last month.

 

 “It’s heart-wrenching. It’s devastating. It’s tough all the way around,” Bob Patterson, the owner of Texas Mountain Ranch, said of losing the captive-bred white-tails that he valued collectively at $280,000.

 

 The positive test in June there marked the first case in Texas of CWD in a captive-raised deer, prompting state officials to restrict the sale and movement of stock held by most deer breeders pending an investigation into the origin and reach of the neurological disease.

 

 “We’ve disallowed movement among breeders to prevent the spread and let us get more information by testing,” said Andy Schwartz, the Texas Animal Health Commission’s assistant executive director of Animal Health Programs and Emergency Management.

 

 That agency developed its response strategy in concert with the Texas Parks and Wildlife Department, which issues permits for deer-breeders and hunters, and with stakeholder groups.

 

 “The two agencies are working closely to determine the source of the disease and detect any possible spread,” Schwartz said.

 

 State officials initially considered taking all 238 deer remaining at Patterson’s ranch north of Hondo, where a 2-year-old buck tested positive for the malady after dying in an accident in June

 

 But a compromise instead allowed testing to start with 35 deer considered to be at the highest risk of contracting CWD. Whether any additional deer there will be killed so their brain stems can be tested will depend, in part, on the results of tests on the deer taken Tuesday, officials said.

 

 “The sooner we can get this resolved, the sooner our fellow breeders can continue in commerce,” Patterson said.

 

 Chronic wasting disease is also called transmissible spongiform encephalopathy, which is similar to bovine spongiform encephalopathy (”mad cow disease”) and scrapie, which affects sheep.

 

 Unlike mad cow disease, CWD is not considered a threat to human health. But state officials say it could devastate both the breeding and hunting industries if it spreads unchecked through the Texas deer population.

 

 Read Wednesday’s Express-News or go to ExpressNews.com for more on this developing story.

 

 zeke@express-news.net

 


 

I kindly submit the following for your files...

 

> The state of Texas euthanized 35 deer Tuesday at a breeding facility in Medina County so they can be tested for chronic wasting disease.

 

WHY ONLY 35 DEER? this is insane. if they don’t slaughter and test every one of those deer for CWD, including the fawns, especially from the index herd, then it’s business as usually in Texas. no telling how much CWD has been trucked from one captive facility to another inside of Texas, from who knows where. besides that, TAHC has known since 2001 that CWD was waltzing across Texas from New Mexico, because I told them it was, not that it mattered. CWD was discovered in 2012 right where I had told them it was in 2001-2002.

 

 IF the state of Texas does not get serious real fast with CWD, and test all those deer, that 5 year plan is a ticking time bomb waiting to happen.

 

 Here are two examples of what waiting can look like with CWD ;

 

 CHRONIC WASTING DISEASE CWD WISCONSIN Almond Deer (Buckhorn Flats) Farm Update DECEMBER 2011 The CWD infection rate was nearly 80%, the highest ever in a North American captive herd. RECOMMENDATION: That the Board approve the purchase of 80 acres of land for $465,000 for the Statewide Wildlife Habitat Program in Portage County and approve the restrictions on public use of the site.SUMMARY:

 


 

 For Immediate Release Thursday, October 2, 2014

 

 Dustin Vande Hoef 515/281-3375 or 515/326-1616 (cell) or Dustin.VandeHoef@IowaAgriculture.gov

 

 TEST RESULTS FROM CAPTIVE DEER HERD WITH CHRONIC WASTING DISEASE RELEASED 79.8 percent of the deer tested positive for the disease

 

 DES MOINES – The Iowa Department of Agriculture and Land Stewardship today announced that the test results from the depopulation of a quarantined captive deer herd in north-central Iowa showed that 284 of the 356 deer, or 79.8% of the herd, tested positive for Chronic Wasting Disease (CWD). The owners of the quarantined herd have entered into a fence maintenance agreement with the Iowa Department of Agriculture and Land Stewardship,which requires the owners to maintain the 8’ foot perimeter fence around the herd premises for five years after the depopulation was complete and the premises had been cleaned and disinfected CWD is a progressive, fatal, degenerative neurological disease of farmed and free-ranging deer, elk, and moose. There is no known treatment or vaccine for CWD. CWD is not a disease that affects humans.On July 18, 2012, USDA Animal and Plant Health Inspection Service’s (APHIS)National Veterinary Services Lab in Ames, IA confirmed that a male whitetail deer harvested from a hunting preserve in southeast IA was positive for CWD. An investigation revealed that this animal had just been introduced into the hunting preserve from the above-referenced captive deer herd in north-central Iowa.The captive deer herd was immediately quarantined to prevent the spread of CWD. The herd has remained in quarantine until its depopulation on August 25 to 27, 2014.The Iowa Department of Agriculture and Land Stewardship participated in a joint operation to depopulate the infected herd with USDA Veterinary Services, which was the lead agency, and USDA Wildlife Services.Federal indemnity funding became available in 2014. USDA APHIS appraised the captive deer herd of 376 animals at that time, which was before depopulation and testing, at $1,354,250. At that time a herd plan was developed with the owners and officials from USDA and the Iowa Department of Agriculture and Land Stewardship.Once the depopulation was complete and the premises had been cleaned and disinfected, indemnity of $917,100.00 from the USDA has been or will be paid to the owners as compensation for the 356 captive deer depopulated.The Iowa Department of Agriculture and Land Stewardship operates a voluntary CWD program for farms that sell live animals. Currently 145 Iowa farms participate in the voluntary program. The above-referenced captive deer facility left the voluntary CWD program prior to the discovery of the disease as they had stopped selling live animals. All deer harvested in a hunting preserve must be tested for CWD. -30-

 


 

 *** see history of this CWD blunder here ;

 


 

 On June 5, 2013, DNR conducted a fence inspection, after gaining approval from surrounding landowners, and confirmed that the fenced had beencut or removed in at least four separate locations; that the fence had degraded and was failing to maintain the enclosure around the Quarantined Premises in at least one area; that at least three gates had been opened;and that deer tracks were visible in and around one of the open areas in the sand on both sides of the fence, evidencing movement of deer into the Quarantined Premises.

 


 

***But details of the plan developed by Texas Animal Health Commission and Texas Parks and Wildlife Department, which include protocols calling for the killing of more than 200 deer on the Medina County property as well as potentially scores of the more than 700 deer the business sold to other captive-deer operations over the past five years, have ignited long-smoldering acrimony from the captive-deer industry and supporters questioning the disease's effects on deer herds, tactics used by state and federal agencies to prevent its spread, and even the nature of the disease.

 


 


 

 Parks and Wildlife meeting addresses chronic wasting disease in Medina County First case in state detected earlier this month

 

 Posted July 16, 2015, 5:28 PMUpdated July 16, 2015, 6:49 PM

 

 ***Patterson said state agencies want to slaughter 139 adult deer and 99 fawns from his ranch July 20 to test for CWD. When KSAT asked Parks and Wildlife Department spokesman Steve Lightfoot if that was true, he said he didn't know if that was the correct number.

 

 Not only does Patterson not believe slaughter is the answer to the problem, he said he's sent nearly 900 deer to 147 facilities across the state. He wants to know when the slaughter will stop, if it starts.

 


 

 Tuesday, July 21, 2015

 

 Texas CWD Medina County Herd Investigation Update July 16, 2015 snip... CWD Working Group Priorities

 

 • Herd plan for management of trace forward herds with testing of exposed animal

 

 • Recommended criteria for movement qualification of herds not in Tier 1

 

 • Index Herd testing/management plan

 

 • Herd Plans for trace forward herds where exposed animal is not tested

 

 • Herd Plan for trace in herds

 

 Five Year Span

 

 • Trace In: 30 facilities, 126 deer

 

 • Trace Forward: 835 deer to 147 facilities

 

 • 96 breeders

 

 • 46 release sites

 

 • 3 DMPs

 

 • 2 International

 

 Trace In Facilities

 

 • Since June 1, 2010 the index herd has received new deer additions from 30 facilities in 30 counties

 

 • Index herd also has a nursing facility that took in fawns from 1 facility in 2010, data is not represented on this map

 

 see map in link...tss

 

 Trace In Facilities

 

 • Since June 1, 2010 the index herd has received new deer additions from 30 facilities in 30 counties

 

 • Index herd also has a nursing facility that took in fawns from 1 facility in 2010, data is not represented on this map

 

 see map in link...tss

 

 Trace Out Facilities

 

 • Counties in which facility owner received deer from index herd since July 1, 2010

 

 • 66 Texas sites, 2 Mexico sites

 

 • Index herd took in fawns from 1 facility in 2010, data is not represented on this map

 

 • All facility owners that have received deer that traced out from the index breeding facility and nursing facility have been sent hold orders

 

 snip...

 


 

 Tuesday, July 21, 2015

 

 Texas CWD Medina County Herd Investigation Update July 16, 2015

 


 

 Tuesday, July 21, 2015

 

 Texas CWD Medina County Herd Investigation Update July 16, 2015

 

 • 66 Texas sites, 2 Mexico sites

 


 

 Wednesday, July 22, 2015

 

 Texas Certified Chronic Wasting Disease CWD Sample Collector, like the Wolf Guarding the Henhouse

 


 

 Thursday, July 23, 2015

 

 *** Chronic Wasting Disease (CWD) 101 Drs. Walter Cook & Donald S. Davis

 


 

 Sunday, July 26, 2015

 

 *** TEXAS IN MELT DOWN MODE OVER CAPTIVE CWD AND THEY ARE PUTTING LIPSTICK ON THAT PIG AND TAKING HER TO THE DANCE LIKE MAD COW DISEASE ***

 


 

 all cervid tested after slaughter, and test results must be released to the public.

 

 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.

 

 New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication

 

 The infectious agents responsible for transmissible spongiform encephalopathy (TSE) are notoriously resistant to most physical and chemical methods used for inactivating pathogens, including heat. It has long been recognized, for example, that boiling is ineffective and that higher temperatures are most efficient when combined with steam under pressure (i.e., autoclaving). As a means of decontamination, dry heat is used only at the extremely high temperatures achieved during incineration, usually in excess of 600°C. It has been assumed, without proof, that incineration totally inactivates the agents of TSE, whether of human or animal origin.

 


 

 Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production

 

 Histochemical analysis of hamster brains inoculated with the solid residue showed typical spongiform degeneration and vacuolation. Re-inoculation of these brains into a new cohort of hamsters led to onset of clinical scrapie symptoms within 75 days, suggesting that the specific infectivity of the prion protein was not changed during the biodiesel process. The biodiesel reaction cannot be considered a viable prion decontamination method for MBM, although we observed increased survival time of hamsters and reduced infectivity greater than 6 log orders in the solid MBM residue. Furthermore, results from our study compare for the first time prion detection by Western Blot versus an infectivity bioassay for analysis of biodiesel reaction products. We could show that biochemical analysis alone is insufficient for detection of prion infectivity after a biodiesel process.

 


 

 Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

 

 The data presented here demonstrate that sPMCA can detect low levels of PrPCWD in the environment, corroborate previous biological and experimental data suggesting long term persistence of prions in the environment2,3 and imply that PrPCWD accumulation over time may contribute to transmission of CWD in areas where it has been endemic for decades. This work demonstrates the utility of sPMCA to evaluate other environmental water sources for PrPCWD, including smaller bodies of water such as vernal pools and wallows, where large numbers of cervids congregate and into which prions from infected animals may be shed and concentrated to infectious levels.

 


 

 A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing

 

 Keywords:Abattoir;bovine spongiform encephalopathy;QRA;scrapie;TSE

 

 In this article the development and parameterization of a quantitative assessment is described that estimates the amount of TSE infectivity that is present in a whole animal carcass (bovine spongiform encephalopathy [BSE] for cattle and classical/atypical scrapie for sheep and lambs) and the amounts that subsequently fall to the floor during processing at facilities that handle specified risk material (SRM). BSE in cattle was found to contain the most oral doses, with a mean of 9864 BO ID50s (310, 38840) in a whole carcass compared to a mean of 1851 OO ID50s (600, 4070) and 614 OO ID50s (155, 1509) for a sheep infected with classical and atypical scrapie, respectively. Lambs contained the least infectivity with a mean of 251 OO ID50s (83, 548) for classical scrapie and 1 OO ID50s (0.2, 2) for atypical scrapie. The highest amounts of infectivity falling to the floor and entering the drains from slaughtering a whole carcass at SRM facilities were found to be from cattle infected with BSE at rendering and large incineration facilities with 7.4 BO ID50s (0.1, 29), intermediate plants and small incinerators with a mean of 4.5 BO ID50s (0.1, 18), and collection centers, 3.6 BO ID50s (0.1, 14). The lowest amounts entering drains are from lambs infected with classical and atypical scrapie at intermediate plants and atypical scrapie at collection centers with a mean of 3 × 10−7 OO ID50s (2 × 10−8, 1 × 10−6) per carcass. The results of this model provide key inputs for the model in the companion paper published here.

 


 

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

 

 Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3

 


 

 Longitudinal Detection of Prion Shedding in Saliva and Urine by CWD-Infected Deer by RT-QuIC

 

 Davin M. Henderson1, Nathaniel D. Denkers1, Clare E. Hoover1, Nina Garbino1, Candace K. Mathiason1 and Edward A. Hoover1# + Author Affiliations

 

 1Prion Research Center, Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523 ABSTRACT Chronic Wasting Disease (CWD) is an emergent, rapidly spreading prion disease of cervids. Shedding of infectious prions in saliva and urine is thought to be an important factor in CWD transmission. To help elucidate this issue, we applied an in vitro amplification assay to determine the onset, duration, and magnitude of prion shedding in longitudinally collected saliva and urine samples from CWD-exposed white-tailed deer. We detected prion shedding as early as 3 months after CWD exposure and sustained shedding throughout the disease course. We estimated that a 50% lethal dose (LD50) for cervidized transgenic mice would be contained in 1 ml of infected deer saliva or 10 ml or urine. Given the average course of infection and daily production of these body fluids, an infected deer would shed thousands of prion infectious dosesover the course of CWD infection. The direct and indirect environmental impact of this magnitude of prion shedding for cervid and non-cervid species is surely significant.

 

 Importance: Chronic wasting disease (CWD) is an emerging and uniformly fatal prion disease affecting free ranging deer and elk and now recognized in 22 United States and 2 C anadian Provinces. It is unique among prion diseases in that it is transmitted naturally though wild populations. A major hypothesis for CWD's florid spread is that prions are shed in excreta and transmitted via direct or indirect environmental contact. Here we use a rapid in vitro assay to show that infectious doses of CWD prions are in fact shed throughout the multi-year disease course in deer. This finding is an important advance in assessing the risks posed by shed CWD prions to animals as well as humans.

 

 FOOTNOTES

 

 ↵#To whom correspondence should be addressed: Edward A. Hoover, Prion Research Center, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, US Email: edward.hoover@colostate.edu

 


 

 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...

 


 

 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

 


 

 CHRONIC WASTING DISEASE CWD TSE PRION, how much does it pay to find CWD $$$

 

 CWD, spreading it around...

 

 for the game farm industry, and their constituents, to continue to believe that they are _NOT_, and or insinuate that they have _NEVER_ been part of the problem, will only continue to help spread cwd. the game farming industry, from the shooting pens, to the urine mills, the antler mills, the sperm mills, velvet mills, shooting pens, to large ranches, are not the only problem, but it is painfully obvious that they have been part of the problem for decades and decades, just spreading it around, as with transportation and or exportation and or importation of cervids from game farming industry, and have been proven to spread cwd. no one need to look any further than South Korea blunder ;

 

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

 

 spreading cwd around...

 

 Between 1996 and 2002, chronic wasting disease was diagnosed in 39 herds of farmed elk in Saskatchewan in a single epidemic. All of these herds were depopulated as part of the Canadian Food Inspection Agency’s (CFIA) disease eradication program. Animals, primarily over 12 mo of age, were tested for the presence CWD prions following euthanasia. Twenty-one of the herds were linked through movements of live animals with latent CWD from a single infected source herd in Saskatchewan, 17 through movements of animals from 7 of the secondarily infected herds.

 

 ***The source herd is believed to have become infected via importation of animals from a game farm in South Dakota where CWD was subsequently diagnosed (7,4). A wide range in herd prevalence of CWD at the time of herd depopulation of these herds was observed. Within-herd transmission was observed on some farms, while the disease remained confined to the introduced animals on other farms.

 


 

 spreading cwd around...

 

 Friday, May 13, 2011

 

 Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea

 

 Hyun-Joo Sohn, Yoon-Hee Lee, Min-jeong Kim, Eun-Im Yun, Hyo-Jin Kim, Won-Yong Lee, Dong-Seob Tark, In- Soo Cho, Foreign Animal Disease Research Division, National Veterinary Research and Quarantine Service, Republic of Korea

 

 Chronic wasting disease (CWD) has been recognized as an important prion disease in native North America deer and Rocky mountain elks. The disease is a unique member of the transmissible spongiform encephalopathies (TSEs), which naturally affects only a few species. CWD had been limited to USA and Canada until 2000.

 

 On 28 December 2000, information from the Canadian government showed that a total of 95 elk had been exported from farms with CWD to Korea. These consisted of 23 elk in 1994 originating from the so-called “source farm” in Canada, and 72 elk in 1997, which had been held in pre export quarantine at the “source farm”.Based on export information of CWD suspected elk from Canada to Korea, CWD surveillance program was initiated by the Ministry of Agriculture and Forestry (MAF) in 2001.

 

 All elks imported in 1997 were traced back, however elks imported in 1994 were impossible to identify. CWD control measures included stamping out of all animals in the affected farm, and thorough cleaning and disinfection of the premises. In addition, nationwide clinical surveillance of Korean native cervids, and improved measures to ensure reporting of CWD suspect cases were implemented.

 

 Total of 9 elks were found to be affected. CWD was designated as a notifiable disease under the Act for Prevention of Livestock Epidemics in 2002.

 

 Additional CWD cases - 12 elks and 2 elks - were diagnosed in 2004 and 2005.

 

 Since February of 2005, when slaughtered elks were found to be positive, all slaughtered cervid for human consumption at abattoirs were designated as target of the CWD surveillance program. Currently, CWD laboratory testing is only conducted by National Reference Laboratory on CWD, which is the Foreign Animal Disease Division (FADD) of National Veterinary Research and Quarantine Service (NVRQS).

 

 In July 2010, one out of 3 elks from Farm 1 which were slaughtered for the human consumption was confirmed as positive. Consequently, all cervid – 54 elks, 41 Sika deer and 5 Albino deer – were culled and one elk was found to be positive. Epidemiological investigations were conducted by Veterinary Epidemiology Division (VED) of NVRQS in collaboration with provincial veterinary services.

 

 Epidemiologically related farms were found as 3 farms and all cervid at these farms were culled and subjected to CWD diagnosis. Three elks and 5 crossbreeds (Red deer and Sika deer) were confirmed as positive at farm 2.

 

 All cervids at Farm 3 and Farm 4 – 15 elks and 47 elks – were culled and confirmed as negative.

 

 Further epidemiological investigations showed that these CWD outbreaks were linked to the importation of elks from Canada in 1994 based on circumstantial evidences.

 

 In December 2010, one elk was confirmed as positive at Farm 5. Consequently, all cervid – 3 elks, 11 Manchurian Sika deer and 20 Sika deer – were culled and one Manchurian Sika deer and seven Sika deer were found to be positive. This is the first report of CWD in these sub-species of deer. Epidemiological investigations found that the owner of the Farm 2 in CWD outbreaks in July 2010 had co-owned the Farm 5.

 

 In addition, it was newly revealed that one positive elk was introduced from Farm 6 of Jinju-si Gyeongsang Namdo. All cervid – 19 elks, 15 crossbreed (species unknown) and 64 Sika deer – of Farm 6 were culled, but all confirmed as negative.

 


 


 


 


 

 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

 

 Chronic wasting disease (CWD) is a widespread and expanding prion disease in free-ranging and captive cervid species in North America. The zoonotic potential of CWD prions is a serious public health concern. Current literature generated with in vitro methods and in vivo animal models (transgenic mice, macaques and squirrel monkeys) reports conflicting results. The susceptibility of human CNS and peripheral organs to CWD prions remains largely unresolved. In our earlier bioassay experiments using several humanized transgenic mouse lines, we detected protease-resistant PrPSc in the spleen of two out of 140 mice that were intracerebrally inoculated with natural CWD isolates, but PrPSc was not detected in the brain of the same mice. Secondary passages with such PrPSc-positive CWD-inoculated humanized mouse spleen tissues led to efficient prion transmission with clear clinical and pathological signs in both humanized and cervidized transgenic mice. Furthermore, a recent bioassay with natural CWD isolates in a new humanized transgenic mouse line led to clinical prion infection in 2 out of 20 mice. 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

 

 The propensity for trans-species prion transmission is related to the structural characteristics of the enciphering and heterologous PrP, but the exact mechanism remains mostly mysterious. Studies of the effects of primary or tertiary prion protein structures on trans-species prion transmission have relied primarily upon animal bioassays, making the influence of prion protein structure vs. host co-factors (e.g. cellular constituents, trafficking, and innate immune interactions) difficult to dissect. As an alternative strategy, we used real-time quakinginduced conversion (RT-QuIC) to investigate trans-species prion conversion.

 

 To assess trans-species conversion in the RT-QuIC system, we compared chronic wasting disease (CWD) and bovine spongiform encephalopathy (BSE) prions, as well as feline CWD (fCWD) and feline spongiform encephalopathy (FSE). Each prion was seeded into each host recombinant PrP (full-length rPrP of white-tailed deer, bovine or feline). We demonstrated that fCWD is a more efficient seed for feline rPrP than for white-tailed deer rPrP, which suggests adaptation to the new host.

 

 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.***

 

 ================

 

 Willingham, Erin McNulty, Kelly Anderson, Jeanette Hayes-Klug, Amy Nalls, and Candace Mathiason Colorado State University; Fort Collins, CO USA

 

 Chronic wasting disease (CWD) is the transmissible spongiform encephalopathy (TSE), of free-ranging and captive cervids (deer, elk and moose).

 

 The presence of infectious prions in the tissues, bodily fluids and environments of clinical and preclinical CWD-infected animals is thought to account for its high transmission efficiency. Recently it has been recognized that mother to offspring transmission may contribute to the facile transmission of some TSEs. Although the mechanism behind maternal transmission is not yet known, the extended asymptomatic TSE carrier phase (lasting years to decades) suggests that it may have implications in the spread of prions.

 

 Placental trafficking and/or secretion in milk are 2 means by which maternal prion transmission may occur. In these studies we explore these avenues during early and late infection using a transgenic mouse model expressing cervid prion protein. Na€ıve and CWD-infected dams were bred at both timepoints, and were allowed to bear and raise their offspring. Milk was collected from the dams for prion analysis, and the offspring were observed for TSE disease progression. Terminal tissues harvested from both dams and offspring were analyzed for prions.

 

 We have demonstrated that

 

 (1) CWDinfected TgCerPRP females successfully breed and bear offspring, and

 

 (2) the presence of PrPCWD in reproductive and mammary tissue from CWD-infected dams.

 

 We are currently analyzing terminal tissue harvested from offspring born to CWD-infected dams for the detection of PrPCWD and amplification competent prions. These studies will provide insight into the potential mechanisms and biological significance associated with mother to offspring transmission of TSEs.

 

 ==============

 

 P.157: Uptake of prions into plants

 

 Christopher Johnson1, Christina Carlson1, Matthew Keating1,2, Nicole Gibbs1, Haeyoon Chang1, Jamie Wiepz1, and Joel Pedersen1 1USGS National Wildlife Health Center; Madison, WI USA; 2University of Wisconsin - Madison; Madison, WI USA

 

 Soil may preserve chronic wasting disease (CWD) and scrapie infectivity in the environment, making consumption or inhalation of soil particles a plausible mechanism whereby na€ıve animals can be exposed to prions. Plants are known to absorb a variety of substances from soil, including whole proteins, yet the potential for plants to take up abnormal prion protein (PrPTSE) and preserve prion infectivity is not known. In this study, we assessed PrPTSE uptake into roots using laser scanning confocal microscopy with fluorescently tagged PrPTSE and we used serial protein misfolding cyclic amplification (sPMCA) and detect and quantify PrPTSE levels in plant aerial tissues. Fluorescence was identified in the root hairs of the model plant Arabidopsis thaliana, as well as the crop plants alfalfa (Medicago sativa), barley (Hordeum vulgare) and tomato (Solanum lycopersicum) upon exposure to tagged PrPTSE but not a tagged control preparation. Using sPMCA, we found evidence of PrPTSE in aerial tissues of A. thaliana, alfalfa and maize (Zea mays) grown in hydroponic cultures in which only roots were exposed to PrPTSE. Levels of PrPTSE in plant aerial tissues ranged from approximately 4 £ 10 ¡10 to 1 £ 10 ¡9 g PrPTSEg ¡1 plant dry weight or 2 £ 105 to 7 £ 106 intracerebral ID50 unitsg ¡1 plant dry weight. Both stems and leaves of A. thaliana grown in culture media containing prions are infectious when intracerebrally-injected into mice. ***Our results suggest that prions can be taken up by plants and that contaminated plants may represent a previously unrecognized risk of human, domestic species and wildlife exposure to prions.

 

 ===========

 

 ***Our results suggest that prions can be taken up by plants and that contaminated plants may represent a previously unrecognized risk of human, domestic species and wildlife exposure to prions.***

 

 SEE ;

 

 Friday, May 15, 2015

 

 Grass Plants Bind, Retain, Uptake, and Transport Infectious Prions

 

 Report

 


 

 ============

 

 P.19: Characterization of chronic wasting disease isolates from freeranging deer (Odocoileus sp) in Alberta and Saskatchewan, Canada

 

 Camilo Duque Velasquez1, Chiye Kim1, Nathalie Daude1, Jacques van der Merwe1, Allen Herbst1, Trent Bollinger2, Judd Aiken1, and Debbie McKenzie1 1Centre for Prions and Protein Folding Diseases; University of Alberta; Edmonton, Canada; 2Western College of Veterinary Medicine; University of Saskatchewan; Saskatoon, Canada

 

 Chronic wasting disease (CWD) is an emerging prion disease of free ranging and captive species of Cervidae. In North America, CWD is enzootic in some wild cervid populations and can circulate among different deer species. The contagious nature of CWD prions and the variation of cervid PRNP alleles, which influence host susceptibility, can result in the emergence and adaptation of different CWD strains. These strains may impact transmission host range, disease diagnosis, spread dynamics and efficacy of potential vaccines. We are characterizing different CWD agents by biochemical analysis of the PrPCWD conformers, propagation in vitro cell assays1 and by comparing transmission properties and neuropathology in Tg33 (Q95G96) and Tg60 (Q95S96) mice.2 Although Tg60 mice expressing S96- PrPC have been shown resistant to CWD infectivity from various cervid species,2,3

 

 ***these transgenic mice are susceptible to H95 C CWD, a CWD strain derived from experimental infection of deer expressing H95G96-PrPC. The diversity of strains present in free-ranging mule deer (Odocoileus hemionus) and white-tailed deer (Odocoileus virginianus) from Alberta and Saskatchewan is being determined and will allow us to delineate the properties of CWD agents circulating in CWD enzootic cervid populations of Canada.

 

 References

 

 1. van der Merwe J, Aiken J, Westaway D, McKenzie D. The standard scrapie cell assay: Development, utility and prospects. Viruses 2015; 7(1):180–198; PMID:25602372; http://dx.doi.org/10.3390/v7010180

 

 2. Meade-White K, Race B, Trifilo M, Bossers A, Favara C, Lacasse R, Miller M, Williams E, Oldstone M, Race R, Chesebro B. Resistance to chronic wasting disease in transgenic mice expressing a naturally occurring allelic variant of deer prion protein. J Virol 2007; 81(9):4533–4539; PMID: 17314157; http://dx. doi.org/10.1128/JVI.02762-06

 

 3. Race B, Meade-White K, Miller MW, Fox KA, Chesebro B. In vivo comparison of chronic wasting disease infectivity from deer with variation at prion protein residue 96. J Virol 2011; 85(17):9235–9238; PMID: 21697479; http://dx.doi.org/10.1128/JVI.00790-11

 

 =========

 

 ***these transgenic mice are susceptible to H95 C CWD, a CWD strain derived from experimental infection of deer expressing H95G96-PrPC.

 

 ==========

 

 P.136: Mother to offspring transmission of CWD—Detection in fawn tissues using the QuIC assay

 

 Amy Nalls, Erin McNulty, Clare Hoover, Jeanette Hayes-Klug, Kelly Anderson, Edward Hoover, and Candace Mathiason Colorado State University; Fort Collins, CO USA

 

 To investigate the role mother to offspring transmission plays in chronic wasting disease (CWD), we have employed a small, polyestrous breeding, indoor maintainable cervid model, the Reeves’ muntjac deer. Muntjac doe were inoculated with CWD and tested positive by lymphoid biopsy at 4 months post inoculation. From these CWD-infected doe, we obtained 3 viable fawns. These fawns tested IHC-positive for CWD by lymphoid biopsy as early as 40 d post birth, and all have been euthanized due to clinical disease at 31, 34 and 59 months post birth. The QuIC assay demonstrates sensitivity and specificity in the detection of conversion competent prions in peripheral IHC-positive tissues including tonsil, mandibular, partotid, retropharyngeal, and prescapular lymph nodes, adrenal gland, spleen and liver. In summary, using the muntjac deer model, we have demonstrated CWD clinical disease in offspring born to CWD-infected doe and found that the QuIC assay is an effective tool in the detection of prions in peripheral tissues. ***Our findings demonstrate that transmission of prions from mother to offspring can occur, and may be underestimated for all prion diseases.

 

 ===============

 

 ***Our findings demonstrate that transmission of prions from mother to offspring can occur, and may be underestimated for all prion diseases.

 

 ===============

 


 

 I strenuously once again urge the FDA and its industry constituents, to make it MANDATORY that all ruminant feed be banned to all ruminants, and this should include all cervids as soon as possible for the following reasons...

 

 ======

 

 In the USA, under the Food and Drug Administrations 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.

 

 ======

 

 31 Jan 2015 at 20:14 GMT

 

 *** Ruminant feed ban for cervids in the United States? ***

 

 Singeltary et al

 

 31 Jan 2015 at 20:14 GMT

 


 

Friday, May 22, 2015

 

 *** Chronic Wasting Disease and Program Updates - 2014 NEUSAHA Annual Meeting 12-14 May 2014 ***

 


 

 Saturday, May 30, 2015

 

 PRION 2015 ORAL AND POSTER CONGRESSIONAL ABSTRACTS

 


 


 

 98 | Veterinary Record | January 24, 2015

 

 EDITORIAL

 

 Scrapie: a particularly persistent pathogen

 

 Cristina Acín

 

 Resistant prions in the environment have been the sword of Damocles for scrapie control and eradication. Attempts to establish which physical and chemical agents could be applied to inactivate or moderate scrapie infectivity were initiated in the 1960s and 1970s,with the first study of this type focusing on the effect of heat treatment in reducing prion infectivity (Hunter and Millson 1964). Nowadays, most of the chemical procedures that aim to inactivate the prion protein are based on the method developed by Kimberlin and collaborators (1983). This procedure consists of treatment with 20,000 parts per million free chlorine solution, for a minimum of one hour, of all surfaces that need to be sterilised (in laboratories, lambing pens, slaughterhouses, and so on). Despite this, veterinarians and farmers may still ask a range of questions, such as ‘Is there an official procedure published somewhere?’ and ‘Is there an international organisation which recommends and defines the exact method of scrapie decontamination that must be applied?’

 

 From a European perspective, it is difficult to find a treatment that could be applied, especially in relation to the disinfection of surfaces in lambing pens of affected flocks. A 999/2001 EU regulation on controlling spongiform encephalopathies (European Parliament and Council 2001) did not specify a particular decontamination measure to be used when an outbreak of scrapie is diagnosed. There is only a brief recommendation in Annex VII concerning the control and eradication of transmissible spongiform encephalopathies (TSE s).

 

 Chapter B of the regulation explains the measures that must be applied if new caprine animals are to be introduced to a holding where a scrapie outbreak has previously been diagnosed. In that case, the statement indicates that caprine animals can be introduced ‘provided that a cleaning and disinfection of all animal housing on the premises has been carried out following destocking’.

 

 Issues around cleaning and disinfection are common in prion prevention recommendations, but relevant authorities, veterinarians and farmers may have difficulties in finding the specific protocol which applies. The European Food and Safety Authority (EFSA ) published a detailed report about the efficacy of certain biocides, such as sodium hydroxide, sodium hypochlorite, guanidine and even a formulation of copper or iron metal ions in combination with hydrogen peroxide, against prions (EFSA 2009). The report was based on scientific evidence (Fichet and others 2004, Lemmer and others 2004, Gao and others 2006, Solassol and others 2006) but unfortunately the decontamination measures were not assessed under outbreak conditions.

 

 The EFSA Panel on Biological Hazards recently published its conclusions on the scrapie situation in the EU after 10 years of monitoring and control of the disease in sheep and goats (EFSA 2014), and one of the most interesting findings was the Icelandic experience regarding the effect of disinfection in scrapie control. The Icelandic plan consisted of: culling scrapie-affected sheep or the whole flock in newly diagnosed outbreaks; deep cleaning and disinfection of stables, sheds, barns and equipment with high pressure washing followed by cleaning with 500 parts per million of hypochlorite; drying and treatment with 300 ppm of iodophor; and restocking was not permitted for at least two years. Even when all of these measures were implemented, scrapie recurred on several farms, indicating that the infectious agent survived for years in the environment, even as many as 16 years after restocking (Georgsson and others 2006).

 

 In the rest of the countries considered in the EFSA (2014) report, recommendations for disinfection measures were not specifically defined at the government level. In the report, the only recommendation that is made for sheep is repopulation with sheep with scrapie-resistant genotypes. This reduces the risk of scrapie recurrence but it is difficult to know its effect on the infection.

 

 Until the EFSA was established (in May 2003), scientific opinions about TSE s were provided by the Scientific Steering Committee (SSC) of the EC, whose advice regarding inactivation procedures focused on treating animal waste at high temperatures (150°C for three hours) and high pressure alkaline hydrolysis (SSC 2003). At the same time, the TSE Risk Management Subgroup of the Advisory Committee on Dangerous Pathogens (ACDP) in the UK published guidance on safe working and the prevention of TSE infection. Annex C of the ACDP report established that sodium hypochlorite was considered to be effective, but only if 20,000 ppm of available chlorine was present for at least one hour, which has practical limitations such as the release of chlorine gas, corrosion, incompatibility with formaldehyde, alcohols and acids, rapid inactivation of its active chemicals and the stability of dilutions (ACDP 2009).

 

 In an international context, the World Organisation for Animal Health (OIE) does not recommend a specific disinfection protocol for prion agents in its Terrestrial Code or Manual. Chapter 4.13 of the Terrestrial Code, General recommendations on disinfection and disinsection (OIE 2014), focuses on foot-and-mouth disease virus, mycobacteria and Bacillus anthracis, but not on prion disinfection. Nevertheless, the last update published by the OIE on bovine spongiform encephalopathy (OIE 2012) indicates that few effective decontamination techniques are available to inactivate the agent on surfaces, and recommends the removal of all organic material and the use of sodium hydroxide, or a sodium hypochlorite solution containing 2 per cent available chlorine, for more than one hour at 20ºC.

 

 The World Health Organization outlines guidelines for the control of TSE s, and also emphasises the importance of mechanically cleaning surfaces before disinfection with sodium hydroxide or sodium hypochlorite for one hour (WHO 1999).

 

 Finally, the relevant agencies in both Canada and the USA suggest that the best treatments for surfaces potentially contaminated with prions are sodium hydroxide or sodium hypochlorite at 20,000 ppm. This is a 2 per cent solution, while most commercial household bleaches contain 5.25 per cent sodium hypochlorite. It is therefore recommended to dilute one part 5.25 per cent bleach with 1.5 parts water (CDC 2009, Canadian Food Inspection Agency 2013).

 

 So what should we do about disinfection against prions? First, it is suggested that a single protocol be created by international authorities to homogenise inactivation procedures and enable their application in all scrapie-affected countries. Sodium hypochlorite with 20,000 ppm of available chlorine seems to be the procedure used in most countries, as noted in a paper summarised on p 99 of this issue of Veterinary Record (Hawkins and others 2015). But are we totally sure of its effectiveness as a preventive measure in a scrapie outbreak? Would an in-depth study of the recurrence of scrapie disease be needed?

 

 What we can conclude is that, if we want to fight prion diseases, and specifically classical scrapie, we must focus on the accuracy of diagnosis, monitoring and surveillance; appropriate animal identification and control of movements; and, in the end, have homogeneous and suitable protocols to decontaminate and disinfect lambing barns, sheds and equipment available to veterinarians and farmers. Finally, further investigations into the resistance of prion proteins in the diversity of environmental surfaces are required.

 

 References

 

 snip...

 

 98 | Veterinary Record | January 24, 2015

 


 

 Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination

 

 Steve A. C. Hawkins, MIBiol, Pathology Department1, Hugh A. Simmons, BVSc MRCVS, MBA, MA Animal Services Unit1, Kevin C. Gough, BSc, PhD2 and Ben C. Maddison, BSc, PhD3 + Author Affiliations

 

 1Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK 2School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK 3ADAS UK, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK E-mail for correspondence: ben.maddison@adas.co.uk Abstract Scrapie of sheep/goats and chronic wasting disease of deer/elk are contagious prion diseases where environmental reservoirs are directly implicated in the transmission of disease. In this study, the effectiveness of recommended scrapie farm decontamination regimens was evaluated by a sheep bioassay using buildings naturally contaminated with scrapie. Pens within a farm building were treated with either 20,000 parts per million free chorine solution for one hour or were treated with the same but were followed by painting and full re-galvanisation or replacement of metalwork within the pen. Scrapie susceptible lambs of the PRNP genotype VRQ/VRQ were reared within these pens and their scrapie status was monitored by recto-anal mucosa-associated lymphoid tissue. All animals became infected over an 18-month period, even in the pen that had been subject to the most stringent decontamination process. These data suggest that recommended current guidelines for the decontamination of farm buildings following outbreaks of scrapie do little to reduce the titre of infectious scrapie material and that environmental recontamination could also be an issue associated with these premises.

 

 SNIP...

 

 Discussion

 

 Thorough pressure washing of a pen had no effect on the amount of bioavailable scrapie infectivity (pen B). The routine removal of prions from surfaces within a laboratory setting is treatment for a minimum of one hour with 20,000 ppm free chlorine, a method originally based on the use of brain macerates from infected rodents to evaluate the effectiveness of decontamination (Kimberlin and others 1983). Further studies have also investigated the effectiveness of hypochlorite disinfection of metal surfaces to simulate the decontamination of surgical devices within a hospital setting. Such treatments with hypochlorite solution were able to reduce infectivity by 5.5 logs to lower than the sensitivity of the bioassay used (Lemmer and others 2004). Analogous treatment of the pen surfaces did not effectively remove the levels of scrapie infectivity over that of the control pens, indicating that this method of decontamination is not effective within a farm setting. This may be due to the high level of biological matrix that is present upon surfaces within the farm environment, which may reduce the amount of free chlorine available to inactivate any infectious prion. Remarkably 1/5 sheep introduced into pen D had also became scrapie positive within nine months, with all animals in this pen being RAMALT positive by 18 months of age. Pen D was no further away from the control pen (pen A) than any of the other pens within this barn. Localised hot spots of infectivity may be present within scrapie-contaminated environments, but it is unlikely that pen D area had an amount of scrapie contamination that was significantly different than the other areas within this building. Similarly, there were no differences in how the biosecurity of pen D was maintained, or how this pen was ventilated compared with the other pens. This observation, perhaps, indicates the slower kinetics of disease uptake within this pen and is consistent with a more thorough prion removal and recontamination. These observations may also account for the presence of inadvertent scrapie cases within other studies, where despite stringent biosecurity, control animals have become scrapie positive during challenge studies using barns that also housed scrapie-affected animals (Ryder and others 2009). The bioassay data indicate that the exposure of the sheep to a farm environment after decontamination efforts thought to be effective in removing scrapie is sufficient for the animals to become infected with scrapie. The main exposure routes within this scenario are likely to be via the oral route, during feeding and drinking, and respiratory and conjunctival routes. It has been demonstrated that scrapie infectivity can be efficiently transmitted via the nasal route in sheep (Hamir and others 2008), as is the case for CWD in both murine models and in white-tailed deer (Denkers and others 2010, 2013). Recently, it has also been demonstrated that CWD prions presented as dust when bound to the soil mineral montmorillonite can be infectious via the nasal route (Nichols and others 2013). When considering pens C and D, the actual source of the infectious agent in the pens is not known, it is possible that biologically relevant levels of prion survive on surfaces during the decontamination regimen (pen C). With the use of galvanising and painting (pen D) covering and sealing the surface of the pen, it is possible that scrapie material recontaminated the pens by the movement of infectious prions contained within dusts originating from other parts of the barn that were not decontaminated or from other areas of the farm.

 

 Given that scrapie prions are widespread on the surfaces of affected farms (Maddison and others 2010a), irrespective of the source of the infectious prions in the pens, this study clearly highlights the difficulties that are faced with the effective removal of environmentally associated scrapie infectivity. This is likely to be paralleled in CWD which shows strong similarities to scrapie in terms of both the dissemination of prions into the environment and the facile mode of disease transmission. These data further contribute to the understanding that prion diseases can be highly transmissible between susceptible individuals not just by direct contact but through highly stable environmental reservoirs that are refractory to decontamination.

 

 The presence of these environmentally associated prions in farm buildings make the control of these diseases a considerable challenge, especially in animal species such as goats where there is lack of genetic resistance to scrapie and, therefore, no scope to re-stock farms with animals that are resistant to scrapie.

 

 Scrapie Sheep Goats Transmissible spongiform encephalopathies (TSE) Accepted October 12, 2014. Published Online First 31 October 2014

 


 

 Monday, November 3, 2014

 

 Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination

 


 

 PPo3-22:

 

 Detection of Environmentally Associated PrPSc on a Farm with Endemic Scrapie

 

 Ben C. Maddison,1 Claire A. Baker,1 Helen C. Rees,1 Linda A. Terry,2 Leigh Thorne,2 Susan J. Belworthy2 and Kevin C. Gough3 1ADAS-UK LTD; Department of Biology; University of Leicester; Leicester, UK; 2Veterinary Laboratories Agency; Surry, KT UK; 3Department of Veterinary Medicine and Science; University of Nottingham; Sutton Bonington, Loughborough UK

 

 Key words: scrapie, evironmental persistence, sPMCA

 

 Ovine scrapie shows considerable horizontal transmission, yet the routes of transmission and specifically the role of fomites in transmission remain poorly defined. Here we present biochemical data demonstrating that on a scrapie-affected sheep farm, scrapie prion contamination is widespread. It was anticipated at the outset that if prions contaminate the environment that they would be there at extremely low levels, as such the most sensitive method available for the detection of PrPSc, serial Protein Misfolding Cyclic Amplification (sPMCA), was used in this study. We investigated the distribution of environmental scrapie prions by applying ovine sPMCA to samples taken from a range of surfaces that were accessible to animals and could be collected by use of a wetted foam swab. Prion was amplified by sPMCA from a number of these environmental swab samples including those taken from metal, plastic and wooden surfaces, both in the indoor and outdoor environment. At the time of sampling there had been no sheep contact with these areas for at least 20 days prior to sampling indicating that prions persist for at least this duration in the environment. These data implicate inanimate objects as environmental reservoirs of prion infectivity which are likely to contribute to disease transmission.

 


 

 

*** Approximately 4,200 fawns, defined as deer under 1 year of age, were sampled from the eradication zone over the last year. The majority of fawns sampled were between the ages of 5 to 9 months, though some were as young as 1 month. Two of the six fawns with CWD detected were 5 to 6 months old. All six of the positive fawns were taken from the core area of the CWD eradication zone where the highest numbers of positive deer have been identified.

 

 "This is the first intensive sampling for CWD in fawns anywhere," said Dr. Julie Langenberg, Department of Natural Resources wildlife veterinarian, "and we are trying to learn as much as we can from these data".

 


 

 Saturday, February 04, 2012

 

 Wisconsin 16 MONTH age limit on testing dead deer Game Farm CWD Testing Protocol Needs To Be Revised

 


 

 Articles of Significant Interest Selected from This Issue by the Editors Next Section Prions in the Blood of Infected Hosts: Early and Persistent Prions circulate in the blood of prion-infected hosts, including humans with variant Creutzfeldt-Jakob disease. Determining the parameters of blood-borne prions during the long asymptomatic phase of disease characteristic of all prion diseases has been a long-standing problem in prion biology. Elder et. al (p. 7421–7424) have demonstrated amyloid formation, a biomarker for prions, in the blood of prion-infected rodent and cervid hosts as early as 15 minutes post-mucosal or -intravenous infection. This prionemia persists throughout the disease course, indicating a role for hematogenous prions throughout the preclinical stage of illness.

 


 

 ***Immediate and Ongoing Detection of Prions in the Blood of Hamsters and Deer following Oral, Nasal, or Blood Inoculations

 

 Alan M. Eldera, Davin M. Hendersona, Amy V. Nallsa, Edward A. Hoovera, Anthony E. Kincaidb,c, Jason C. Bartzb and Candace K. Mathiasona aDepartment of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA bMedical Microbiology and Immunology, Creighton University, Omaha, Nebraska, USA cDepartment of Pharmacy Sciences, Creighton University, Omaha, Nebraska, USA S. Perlman, Editor + Author Affiliations

 


 

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 ;

 


 

 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.

 


 

 Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle

 

 Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.

 

 snip...

 

 The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...

 


 

 In Confidence - Perceptions of unconventional slow virus diseases of animals in the USA - APRIL-MAY 1989 - G A H Wells

 

 3. Prof. A. Robertson gave a brief account of BSE. The US approach was to accord it a very low profile indeed. Dr. A Thiermann showed the picture in the ''Independent'' with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs. ...

 


 

 


 

 

Terry S. Singeltary Sr.

 

Bacliff, Texas USA 77518

 


 

Tuesday, July 28, 2015

 

TEXAS Kills 35 Deer at Medina County Ranch (Texas Captive CWD)