Saturday, October 5, 2019

Variably protease‐sensitive prionopathy mimicking frontotemporal dementia

Variably protease‐sensitive prionopathy mimicking frontotemporal dementia

Miren Aizpurua Sashika Selvackadunco Helen Yull Christopher M. Kipps James W. Ironside Istvan Bodi First published: 07 March 2019 https://doi.org/10.1111/neup.12538

Abstract

Sporadic prion diseases are fatal neurodegenerative disorders characterized clinically by rapidly progressive dementia and myoclonus. Variably protease‐sensitive prionopathy (VPSPr) is a recently identified sporadic human prion disorder that may present with a lengthy atypical clinical history. Here, we describe a case of VPSPr in a patient with a long history of suspected frontotemporal dementia (FTD). A 61‐year‐old man presented with speech difficulties, including naming objects and constructing multipart sentences, while there was no difficulty in comprehension. Movement abnormalities included slightly jerky pursuit, minor dysmetria of saccades and brisk reflexes. There was no family history of dementia. Later he developed swallowing difficulties and the possibility of FTD with motor neuron disease was suspected. He died at the age of 71 and his brain was donated to the London Neurodegenerative Diseases Brain Bank. The brain (1004 g) showed mild to moderate atrophy, predominantly in the frontal lobe. Histology revealed moderate spongiform microvacuolation mostly affecting the frontal and parietal cortices, but also present focally in the basal ganglia and the cerebellum. Only mild Alzheimer pathology was found by extensive immunohistochemistry, in keeping with BrainNet Europe stage II. Trans‐activation response DNA‐binding protein 43 kDa and α‐synuclein immunostains were negative. Immunostaining for prion protein (PrP) showed granular/synaptic positivity in a patchy distribution, mainly within the deeper cortex, and also revealed microplaques in the cerebellum and basal ganglia. Western blotting confirmed a low molecular weight protease‐resistant PrP band with a faint ladder‐like pattern in the absence of types 1 and 2 isoforms. These features are diagnostic of VPSPr. VPSPr can mimic various neurodegenerative conditions; diagnosis requires both PrP immunohistochemistry and Western blotting. The presence of patchy spongiform change in the absence of other neurodegenerative pathology should raise suspicion of VPSPr, even in elderly patients with a lengthy clinical history.

INTRODUCTION

Human prion diseases are fatal neurodegenerative disorders that are characterized neuropathologically by the abnormal accumulation of a misfolded prion protein (PrP) in the central nervous system. The mechanism by which the cellular PrP (PrPC) is converted into the pathogenic scrapie‐type PrP (PrPSc) appears to involve a post‐translational change in PrPC conformation, from a predominantly α‐helical into a predominantly β‐sheet structure.1 PrPSc is the major, if not the sole, component of the transmissible agent in prion diseases. PrPSc is relatively insoluble and aggregates extracellularly, possibly inducing adjacent tissue malfunction, although the exact pathological mechanism is still unclear. Human prion diseases differ not only in their clinical and neuropathological features, but also in the biochemical features (differential glycosylation and relatively resistance to proteinase digestion) of PrPSc in the brain, making prionopathies a much more heterogeneous group of disorders than initially considered.

Human prion diseases are classified into three main categories: sporadic, acquired or genetic (familial). Sporadic Creutzfeldt–Jakob disease (sCJD) is the most common human prion disease, occurring world‐wide and characterized clinically by rapidly progressive dementia and myoclonus. However, sCJD is known to be clinically and pathologically heterogeneous, and is currently sub‐classified into six subtypes.2 The molecular basis for this heterogeneity is thought to correspond to an interaction between the naturally occurring methionine/valine polymorphism at codon 129 of the prion protein gene (PRNP) (MM, MV, or VV) and the abnormal prion protein isoform in the brain, as determined by Western blot analysis of the protease‐resistant band (termed PrPres) obtained by treating PrPSc with protease K. The resulting bands are then classified by their molecular weight as type 1 or type 2.3, 4 Recent investigations have identified another sporadic human prion disease, termed variably protease‐sensitive prionopathy (VPSPr) which lacks PRNP mutations but is clinically and biochemically different from sporadic CJD.5 Here, we report a case of VPSPr in a UK patient with a lengthy clinical history mimicking frontotemporal dementia.

CLINICAL SUMMARY

Brain donation to the London Neurodegenerative Diseases Brain Bank for research was received from a 71‐year‐old man. He presented at the age of 69 with 8 years history of speech difficulties. He apparently had a stressful time some years ago when selling his company and noticed that his speech was less fluent and he became prone to making dysphasic errors. He also noticed a slight change in handwriting. Although the onset of the disease was very slow, his partner did highlight a substantial change in his attention, some degree of repetitive questioning and memory disturbances such as loosing or misplacing objects and forgetting the names of people and objects. He lost track of his thoughts if he was interrupted; however, there was no topographical disorientation. He had no difficulty with self‐care and there were no mood or behavioral disturbance, although a slight reduction in motivation was observed. No visual hallucinations were reported. There was no family history of neurological disease. On examination, a mild expressive dysphasia with a degree of orobuccal apraxia was observed; his speech was prone to error with longer words and he had difficulty in repeating polysyllabic words and multipart sentences, but there was no difficulty with comprehension. There were no visuospatial errors, but he had difficulty with writing and some spelling limitations. There were no parkinsonian signs, but there was slightly jerky pursuit both horizontally and vertically as well as possibly minor dysmetria of saccades. There were occasional limb muscle fasciculations without associated weakness. His Mini‐Mental State Examination was 26/30 and cognitive examination (ACE‐R) score of 84/100. magnetic resonance imaging showed generalized involutional change and several non‐specific high signal lesions. The clinical features favored primary progressive non‐fluent aphasia (PPA) and hexylmethylpropylene amineoxine – single‐photon emission computed tomography scan showed an inferior frontal hypoperfusion, in keeping with PPA in September 2014 (Fig. 1). Nerve conduction studies identified benign fasciculations, but nothing consistent with motor neuron disease (MND). Genetic testing for C9orf72 was negative. His neurodegenerative condition progressed following presentation, and he developed swallowing difficulties, subsequent aspiration pneumonias as well as seizures. He died at age 71, 10 years after the initial presentation.

PATHOLOGICAL FINDINGS According to our brain bank protocol the right half of the brain was sampled fresh and stored in a freezer at −80°C, while the left half of the brain was fixed in formalin and processed for neuropathological examination. The fresh brain weight was 1004 g; the formalin fixed left brain weighed 509 g and the left brainstem and cerebellum hemisphere weighed 90 g. There was mild to moderate generalized cortical atrophy, slightly more prominent in the frontal lobe and around the Sylvian fissure. Mild ventricular dilatation and a slightly smaller hippocampus were also seen.

Histology of the brain revealed mild to moderate neuronal loss in the neocortex, particularly in the frontal and parieto‐occipital lobes. This was associated with microvacuolation, often involving the deeper cortical layers, and no areas of confluent spongiform change were identified (Fig. 2A–C). The microvacuolation was also noticeable in the basal ganglia, medial thalamic nuclei and the cerebellar cortex, while the hippocampus and the brainstem were relatively spared. Despite the neuronal loss, the overall Alzheimer‐type changes were relatively mild by extensive immunohistochemistry. Amyloid‐β (Millipore, Watford, UK) deposition was more widespread, in keeping with Thal phase 3 and Consortium to Establish a Registry for Alzheimer Disease plaque stage A. There was no significant amyloid angiopathy, although a few leptomeningeal blood vessels were labelled by amyloid‐β. The hyperphosphorylated tau (ThermoFisher Scientific, Lutterworth, UK) positive pathology was relatively mild, in keeping with BrainNet Europe (BNE) stage II (NIA‐ABC: A2, B1, C0). Phosphorylated trans‐activation response DNA‐binding protein 43 kDa (ProteinTech, Manchester, UK) and α‐synuclein (BD Biosciences, Wokingham, UK) immunostains were negative.

Immunohistochemistry for PrP showed very similar pattern using the 12F10 (kindly supplied by Professor Hunsmann of the German Primate Centre, Gottingen, Germany) and 3F4 (Dako, Ely, UK) anti‐PrP antibodies, revealing granular/synaptic pattern of accumulation in the cerebral cortex, often in a patchy distribution and particularly in the deeper cortical layers (Fig. 2D–F). There was also labelling in the hippocampus, the basal ganglia and the thalamus. Large numbers of microplaques were seen in the putamen and the cerebellar cortex, particularly within the molecular layer extending up to the subpial regions. No kuru‐type plaques were identified in the cerebellum on hematoxylin and eosin staining or PrP immunohistochemistry.

Analysis of the frozen brain tissue by Western blotting revealed a low molecular weight band in the frontal, temporal, parietal and occipital cortices (Fig. 3). A similar band was present at lesser intensity in the cerebellar cortex and a faint ladder‐like pattern, in the absence of types 1 and 2 isoforms, was also observed in the temporal parietal and occipital cortices. This pattern is diagnostic of VPSPr. Genetic analysis of the codon 129 polymorphism showed valine homozygosity and no mutations in the PrP gene.

DISCUSSION Gambetti et al.5 in 2008 (USA) reported 11 subjects affected by a distinct prionopathy that differed biochemically and clinically from the other sporadic prionopathies and was characterized by the accumulation of a protease‐sensitive misfolded PrP. Since then, some other cases have been described worldwide, demonstrating a higher incidence than initially thought; further cases of VPSPr have been identified prospectively and retrospectively in the USA,6, 7 UK,8-10 the Netherlands,11 Austria12 and Spain.13-15 To date altogether 39 VPSPr cases have been published.

Most sporadic prion diseases are characterized by two main PrPres strains that vary from 21 to 19 kDa fragments obtained after PrPSc proteinase K treatment: types 1 and 2 PrPres, respectively. These two subtypes have been experimentally reported to be associated with a variable quantity of another disease‐associated PrP isoform that differs from PrPc and PrPres in that this PrP strain is insoluble but highly sensitive to proteinase K treatment, henceforth referred to as PrPsen. Although both sCJD and sporadic fatal insomnia (sFI) reveal types 1 or 2 PrPres isoforms and a small amount of PrPsen on Western blotting, VPSPr is characterized by the presence of various isoforms of PrPsen in the absence of type 1 or 2 PrPres isoforms.16 The most interesting aspect of this new disease from a biochemical point of view is that although PrPSc is abundantly present in the brain, conventional PrPres isoforms are difficult to detect on Western blotting because of their relatively increased sensitivity to proteolysis. PrPsen consists of a C‐ and N‐terminally truncated approximately 8 kDa band that is usually accompanied by a ladder of bands that extend between 18 and 30 kDa in range on Western blotting. Moreover, the ladder‐like pattern appears to be dependent on the codon 129 genotype, which adds more complexity to the biochemical features of VPSPr. Indeed, it has been reported that the electrophoretic migration features of the protease‐resistant bands, and thus the ladder‐like profile intensity on Western blotting, vary depending upon the PRNP codon 129 genotypes. It appears that 129MM shows the most intense ladder‐like composition, reflecting a higher PK resistance, whereas 129VV reveals a strong approximately 8 kDa band but faint accompanying ladder‐like bands, hence a lower protease resistance.6 The current case revealed biochemical features similar to those found in VPSPr 129VV; PRNP codon valine homozygosity in our patient was later confirmed by genetic analysis. Not only is the PRNP codon 129 genotype related to a specific electrophoretic pattern, but this genotype also influences the clinical presentation and neuropathological features of VPSPr.16

With regard to the clinical presentation, VPSPr appears to be also different from the other sporadic prionopathies. Sporadic prion diseases, such as sCJD and sFI, are clinically characterized by a rapidly progressive dementia and myoclonus2 or in the case of sFI, by a progressive insomnia, psychiatric disturbances and a relatively short history of dementia. However, VPSPr shows a much lengthier course of disease than either sCJD or sFI. The presenting symptoms consist of a predominantly fronto‐temporal type of dementia with or without Parkinsonism in the absence of sleep disturbances or involuntary muscle contractions.16 The disease progresses toward the development of motor abnormalities, worsening of the initial symptoms and finally enters into an akinetic‐mutism period. Again, depending upon the PRNP codon 129 status, the presenting symptoms will vary; 129VV cases (25/37 confirmed VPSPr), usually reveal a more psychiatric, speech and cognitive‐associated initial decline, whereas the 129MM (5/37 confirmed VPSPr) and 129MV (9/38 confirmed VPSPr) counterparts may not be symptomatic at all (two of the MM cases) or present with more parkinsonian features and fewer behavioral disturbances.6, 17 With regard to the patient described here, the presentation was a long history of language difficulties, with very mild mood disturbances and no signs of parkinsonism or myoclonus. Although there was a minimal memory decline in the beginning, this has only been found to be present at onset in 50% of 129VV cases.6 Unlike 129MM and 129MV genotypes, 129VV does not usually present with parkinsonian features, as in our case. However, as the disease progressed, the patient did show gait disturbances which led him to suffer from several falls and also develop other symptoms that have yet not been linked to any of the genotypes, such as seizures or dysphagia. As seen in 50% of 129VV patients, there was no family history of dementia. The patient died approximately 10 years after the onset of the symptoms.

From a neuropathological perspective, the morphology of VPSPr appears to be consistently similar in the three PRNP codon 129 genotypes,6 but with differences in the intensity of the features. This novel prionopathy is characterized by medium‐sized microvacuolation affecting most of the cerebral areas, variable neuronal loss and distinctive cerebellar molecular layer microplaques. The immunohistochemical PrP pattern also depends on the genotype; it appears to be more severe in 129VV homozygous patients. Our case revealed neocortical neuronal loss, deep and superficial gray matter microvacuolation and cerebellar microplaques. The immunoprofile was consistent with previously published cases of 129VV VPSPr and revealed target and dot‐like immunoexpression with 12F10 and 3F4. In addition, BNE stage II Alzheimer type changes were seen, but no Lewy body pathology was present.

This unexpected case of VPSPr was identified through a brain bank donation and was sampled fresh due to the lack of clinical suggestion of a prionopathy. Several other neurodegenerative conditions were considered prior to the prion immunohistochemistry analysis that allowed the final diagnosis. It is well known that prionopathies, VPSPr included, are transmissible neurodegenerative diseases that pose potential health and safety risks. Although extra health and safety measurements may be advised in suspected prionopathies, it is believed that the standard but rigorous health and safety measures in neuropathology laboratories and brain banks are sufficient to prevent accidental disease transmission. Since VPSPr does not fully follow the typical clinical course for sCJD, it can be expected to occur rarely in future brain bank donations and may cause diagnostic difficulty, particularly if multiple neurodegenerative processes are present. The presence of patchy cerebral cortical spongiform change in the absence of other neurodegenerative pathology should raise the suspicion of VPSPr, even in elderly patients with a lengthy clinical history.

ACKNOWLEDGMENTS The authors are grateful to the relatives for donation to the London Neurodegenerative Diseases Brain Bank and consenting to research.

DISCLOSURE The authors declare no conflict of interest.



*** Conclusions. Preliminary results from transmission studies in bank voles strongly support the notion that VPSPr is a transmissible prion disease. Interestingly, VPSPr undergoes divergent evolution in the two genetic lines of voles, with sCJD-like features in BvM109 and GSS-like properties in BvI109. The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.

OR-10: Variably protease-sensitive prionopathy is transmissible in bank voles 

Romolo Nonno,1 Michele Di Bari,1 Laura Pirisinu,1 Claudia D’Agostino,1 Stefano Marcon,1 Geraldina Riccardi,1 Gabriele Vaccari,1 Piero Parchi,2 Wenquan Zou,3 Pierluigi Gambetti,3 Umberto Agrimi1 1 Istituto Superiore di Sanità; Rome, Italy; 2 Dipartimento di Scienze Neurologiche, Università di Bologna; Bologna, Italy; 3 Case Western Reserve University; Cleveland, OH USA 

Background. Variably protease-sensitive prionopathy (VPSPr) is a recently described “sporadic”neurodegenerative disease involving prion protein aggregation, which has clinical similarities with non-Alzheimer dementias, such as fronto-temporal dementia. Currently, 30 cases of VPSPr have been reported in Europe and USA, of which 19 cases were homozygous for valine at codon 129 of the prion protein (VV), 8 were MV and 3 were MM. A distinctive feature of VPSPr is the electrophoretic pattern of PrPSc after digestion with proteinase K (PK). After PK-treatment, PrP from VPSPr forms a ladder-like electrophoretic pattern similar to that described in GSS cases. The clinical and pathological features of VPSPr raised the question of the correct classification of VPSPr among prion diseases or other forms of neurodegenerative disorders. Here we report preliminary data on the transmissibility and pathological features of VPSPr cases in bank voles. 

Materials and Methods. Seven VPSPr cases were inoculated in two genetic lines of bank voles, carrying either methionine or isoleucine at codon 109 of the prion protein (named BvM109 and BvI109, respectively). Among the VPSPr cases selected, 2 were VV at PrP codon 129, 3 were MV and 2 were MM. Clinical diagnosis in voles was confirmed by brain pathological assessment and western blot for PK-resistant PrPSc (PrPres) with mAbs SAF32, SAF84, 12B2 and 9A2.

Results. To date, 2 VPSPr cases (1 MV and 1 MM) gave positive transmission in BvM109. Overall, 3 voles were positive with survival time between 290 and 588 d post inoculation (d.p.i.). All positive voles accumulated PrPres in the form of the typical PrP27–30, which was indistinguishable to that previously observed in BvM109 inoculated with sCJDMM1 cases. In BvI109, 3 VPSPr cases (2 VV and 1 MM) showed positive transmission until now. Overall, 5 voles were positive with survival time between 281 and 596 d.p.i.. In contrast to what observed in BvM109, all BvI109 showed a GSS-like PrPSc electrophoretic pattern, characterized by low molecular weight PrPres. These PrPres fragments were positive with mAb 9A2 and 12B2, while being negative with SAF32 and SAF84, suggesting that they are cleaved at both the C-terminus and the N-terminus. Second passages are in progress from these first successful transmissions. 

Conclusions. Preliminary results from transmission studies in bank voles strongly support the notion that VPSPr is a transmissible prion disease. Interestingly, VPSPr undergoes divergent evolution in the two genetic lines of voles, with sCJD-like features in BvM109 and GSS-like properties in BvI109. The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.


*** Singeltary comment PLoS *** 

Alzheimer’s disease and Transmissible Spongiform Encephalopathy prion disease, Iatrogenic, what if ? 

Posted by flounder on 05 Nov 2014 at 21:27 GMT 


Published: 09 September 2015

Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy

Zane Jaunmuktane, Simon Mead, Matthew Ellis, Jonathan D. F. Wadsworth, Andrew J. Nicoll, Joanna Kenny, Francesca Launchbury, Jacqueline Linehan, Angela Richard-Loendt, A. Sarah Walker, Peter Rudge, John Collinge & Sebastian Brandner


Re-Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy 

>>> The only tenable public line will be that "more research is required’’ <<< 

>>> possibility on a transmissible prion remains open<<< 

O.K., so it’s about 23 years later, so somebody please tell me, when is "more research is required’’ enough time for evaluation ? 

Re-Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy 

Nature 525, 247?250 (10 September 2015) doi:10.1038/nature15369 Received 26 April 2015 Accepted 14 August 2015 Published online 09 September 2015 Updated online 11 September 2015 Erratum (October, 2015) 

snip...see full Singeltary Nature comment here; 

Alzheimer's disease

let's not forget the elephant in the room. curing Alzheimer's would be a great and wonderful thing, but for starters, why not start with the obvious, lets prove the cause or causes, and then start to stop that. think iatrogenic, friendly fire, or the pass it forward mode of transmission. think medical, surgical, dental, tissue, blood, related transmission. think transmissible spongiform encephalopathy aka tse prion disease aka mad cow type disease... 

Commentary: Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy





SUNDAY, MAY 26, 2019 

Arguments for Alzheimer’s and Parkinson’s diseases caused by prions Stanley B. Prusiner 

''From a large array of bioassays, we conclude that AD, PD, MSA, and the frontotemporal dementias, including PSP and CBD, are all prion diseases''


Friday, January 10, 2014

vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what it ???


FRIDAY, NOVEMBER 3, 2017 

GSS Gerstmann-Sträussler-Scheinker disease with atypical presentation


Friday, January 29, 2016

Synucleinopathies: Past, Present and Future, iatrogenic, what if?



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


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

REVIEW

***> In conclusion, sensory symptoms and loss of reflexes in Gerstmann-Sträussler-Scheinker syndrome can be explained by neuropathological changes in the spinal cord. We conclude that the sensory symptoms and loss of lower limb reflexes in Gerstmann-Sträussler-Scheinker syndrome is due to pathology in the caudal spinal cord. <***

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

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

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

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

Thursday, March 8, 2018

Familial human prion diseases associated with prion protein mutations Y226X and G131V are transmissible to transgenic mice expressing human prion protein


P132 Aged cattle brain displays Alzheimer’s-like pathology that can be propagated in a prionlike manner

Ines Moreno-Gonzalez (1), George Edwards III (1), Rodrigo Morales (1), Claudia Duran-Aniotz (1), Mercedes Marquez (2), Marti Pumarola (2), Claudio Soto (1) 

snip...

These results may contribute to uncover a previously unsuspected etiology surrounding some cases of sporadic AD. However, the early and controversial stage of the field of prion-like transmission in non-prion diseases added to the artificial nature of the animal models utilized for these studies, indicate that extrapolation of the results to humans should not be done without further experiments. 

P75 Determining transmissibility and proteome changes associated with abnormal bovine prionopathy 

Dudas S (1,2), Seuberlich T (3), Czub S (1,2) 

In prion diseases, it is believed that altered protein conformation encodes for different pathogenic strains. Currently 3 different strains of bovine spongiform encephalopathy (BSE) are confirmed. Diagnostic tests for BSE are able to identify animals infected with all 3 strains, however, several diagnostic laboratories have reported samples with inconclusive results which are challenging to classify. It was suggested that these may be novel strains of BSE; to determine transmissibility, brain material from index cases were inoculated into cattle. 

In the first passage, cattle were intra-cranially challenged with brain homogenate from 2 Swiss animals with abnormal prionopathy. The challenged cattle incubated for 3 years and were euthanized with no clinical signs of neurologic disease. Animals were negative when tested on validated diagnostic tests but several research methods demonstrated changes in the prion conformation in these cattle, including density gradient centrifugation and immunohistochemistry. Currently, samples from the P1 animals are being tested for changes in protein levels using 2-D Fluorescence Difference Gel Electrophoresis (2D DIGE) and mass spectrometry. It is anticipated that, if a prionopathy is present, this approach should identify pathways and targets to decipher the source of altered protein conformation. In addition, a second set of cattle have been challenged with brain material from the first passage. Ideally, these cattle will be given a sufficient incubation period to provide a definitive answer to the question of transmissibility. 

=====prion 2018===



***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 Terry S. Singeltary Sr. on 03 Jul 2015 at 16:53 GMT


P.9.21

Molecular characterization of BSE in Canada

Jianmin Yang 1 , Sandor Dudas 2 , Catherine Graham 2 , Markus Czub 3 , Tim McAllister 1 , Stefanie Czub 1 1 Agriculture and Agri-Food Canada Research Centre, Canada; 2 National and OIE BSE Reference Laboratory, Canada; 3 University of Calgary, Canada

Background: Three BSE types (classical and two atypical) have been identified on the basis of molecular characteristics of the misfolded protein associated with the disease. To date, each of these three types have been detected in Canadian cattle. Objectives: This study was conducted to further characterize the 16 Canadian BSE cases based on the biochemical properties of there associated PrPres.

Methods: Immuno-reactivity, molecular weight, glycoform profiles and relative proteinase K sensitivity of the PrPres from each of the 16 confirmed Canadian BSE cases was determined using modified Western blot analysis.

Results: Fourteen of the 16 Canadian BSE cases were C type, 1 was H type and 1 was L type. The Canadian H and L-type BSE cases exhibited size shifts and changes in glycosylation similar to other atypical BSE cases. PK digestion under mild and stringent conditions revealed a reduced protease resistance of the atypical cases compared to the C-type cases. N terminal-specific antibodies bound to PrPres from H type but not from C or L type. The C-terminal-specific antibodies resulted in a shift in the glycoform profile and detected a fourth band in the Canadian H-type BSE.

Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan. This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada. It also suggests a similar cause or source for atypical BSE in these countries.

Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan.

*** This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada.

*** It also suggests a similar cause or source for atypical BSE in these countries. ***

see page 176 of 201 pages...tss



*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics of BSE in Canada Singeltary reply;




SUNDAY, SEPTEMBER 1, 2019 

FDA Reports on VFD Compliance

LET THIS NEXT STATEMENT SINK IN GOOD!

Before and after the current Veterinary Feed Directive (VFD) rules took full effect in January, 2017, the FDA focused primarily on education and outreach to help feed mills, veterinarians and producers understand and comply with the requirements. Since then, FDA has gradually increased the number of VFD inspections and initiated enforcement actions when necessary.


THURSDAY, AUGUST 08, 2019 

Raccoons accumulate PrPSc after intracranial inoculation with the agents of chronic wasting disease (CWD) or transmissible mink encephalopathy (TME) but not atypical scrapie


WEDNESDAY, JULY 31, 2019 

The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L


FELINE SPONGIFORM ENCEPHALOPATHY FSE AND CANINE SPONGIFORM ENCELPHALOPATHY CSE



MONDAY, FEBRUARY 25, 2019

MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019


SUNDAY, MARCH 10, 2019 

National Prion Disease Pathology Surveillance Center Cases Examined¹ Updated Feb 1, 2019 Variably protease-sensitive prionopathy VPSPr


MONDAY, AUGUST 26, 2019 

Creutzfeldt Jakob Disease CJD, TSE, Prion, Surveillance Update August 2019


TEXAS CREUTZFELDT JAKOB DISEASE CJD TSE PRION HAS NOT BEEN UPDATED SINCE 2017;

Texas Creutzfeldt-Jakob Disease Case Counts by Type of Disease and Year (2008-2017)        

Creutzfeldt-Jakob Disease

Data   FAQs   Reporting   Resources

Overview

Creutzfeldt - Jakob disease (CJD) is a rare, fatal brain disorder consisting of four types: sporadic (most common - makes up 85 - 95% of all CJD cases - sometimes referred to as classic), familial (represents 5 - 15% of all CJD cases), variant, and iatrogenic.
Organism/Etiologic Agent
Prion (infectious protein)
Transmission
  • Sporadic CJD (sCJD) – mode of transmission is unknown
  • Familial CJD (fCJD) – inherited
  • Variant CJD (vCJD) – believed to be associated with consumption of beef products from cows contaminated with the agent of mad cow disease.
  • Iatrogenic CJD (iCJD) - transmission can occur through certain medical or surgical procedures.
Symptoms
  • Sporadic CJD (sCJD) Symptoms may include rapidly progressive dementia, myoclonus, ataxia, vision and speech difficulties. Typically occurs in persons greater than 55 years of age. Average duration of illness is 3 months.
  • Familial CJD (fCJD) Symptoms and duration of illness vary depending on type of mutation. Symptoms may be similar to sCJD.
  • Variant CJD (vCJD) Symptoms may include early psychiatric symptoms and dysaesthesia/paresthsias progressing to chorea/dystonia or myoclonus, dementia, ataxia, and/or akinetic mutism. Typically occurs in persons less than 55 years of age (average age 28). Average duration of illness is 13 months.
  • Iatrogenic CJD (iCJD) Symptoms vary depending on portal of entry. If transmission occurs directly to brain symptoms will be similar to sCJD.
Treatment & Prevention
There is no known effective treatment or prevention.
Recent Texas Trends
Creutzfeldt-Jakob Disease (CJD) is a rare, invariably fatal neurodegenerative disease with an incidence rate of approximately 1 case per million population per year. In Texas, the average rate of CJD deaths per million population over the past 5 and past 10 years is 0.85 and 0.85, respectively.
For over 10 years, Texas has carried out enhanced surveillance (passive and active surveillance) for CJD including all sporadic, acquired, and genetic/inheritable forms of human transmissible spongiform encephalopathies (TSEs).
The success of this program is demonstrated by the identification and confirmation of familial, variant, and sporadic cases of CJD, along with cases of Fatal Familial Insomnia (FFI), sporadic Fatal Insomnia (sFI), Gerstmann-Sträussler-Scheinker (GSS) syndrome, and Variably Protease Sensitive Prionopathies (VPSPr). From 2008-2017 Texas has reported 13 familial CJD (fCJD), 2 Fatal Familial Insomnia (FFI), 205 sporadic CJD (sCJD), 1 sporadic Fatal Insomnia (sFI), 3 Variably Protease Sensitive Prionopathy (VPSPr), and 1 variant CJD (vCJD).
The sustainability of this program is evidenced by the average rate of deaths per million population over the past ten years and at the consecutive 5-year intervals within the past 10 years. These rates have remained steady over time as the population of Texas has increased from approximately 24 million to over 28 million in population (2008-2017). The average rate of deaths per million population due to CJD over the past ten years (2008-2017) is 0.85 cases per million population per year. The average rate over two consecutive 5-year periods, 2008-2012 & 2013-2018 are 0.85 & 0.85 (cases per million population per year), respectively.
While the annual number of deaths due to CJD have increased over time, the death rate per million population remains constant; indicating that the increase in case counts is due to the increase in population rather than due to an increase in transmission or new forms of disease. 
In 2014, Texas had the 4th variant CJD case to be reported in the United States. A full description of the case can be found at: http://wwwnc.cdc.gov/eid/article/21/5/pdfs/14-2017.pdf
Maheshwari A, Fischer M, Gambetti P, Parker A, Ram A, Soto C, Concha-Marambio L, Cohen Y, Belay ED, Maddox RA, Mead S, Goodman C, Kass JS, Schonberger LB,Hussein HM. Recent US Case of Variant Creutzfeldt-Jakob Disease-Global Implications. Emerg Infect Dis. 2015 May;21(5):750-9. doi:10.3201/eid2105.142017. PubMed PMID: 25897712; PubMed Central PMCID: PMC4412247.
In late April of 2015, the National Prion Disease Pathology Surveillance Center (NPDPSC) began offering a new ante-mortem CSF test, the “Real-Time Quaking Induced Conversion (RT-QuIC)” test, which is a test for the abnormal/pathogenic form of the prion protein in the CSF. Though this test may aid physicians in the investigation of illness with rapidly progressive dementia, it is not a confirmatory test. Neuropathological analysis of autopsied whole brain tissue remains the only method for confirming and ruling-out prion disease.  
To confirm a diagnosis of CJD neuropathological analysis of brain tissue must be performed. Brain tissue is preferably obtained by autopsy rather than biopsy. Efforts still continue to educate the public and medical providers on the importance of confirming a diagnosis and the services available to those interested in a confirmatory diagnosis (many of them are at no cost to the family). Autopsy is available free through the National Prion Disease Pathology Surveillance Center for all suspect cases of CJD. Please see http://case.edu/medicine/pathology/divisions/prion-center/ for more information.
While CJD remains a NOTIFIABLE CONDITION in Texas, it is still under-reported and misdiagnosed. The under-reporting of disease, the rarity of disease, and the lack of pre-mortem confirmatory diagnostic tests all contribute to rates below the expected 1.0 case per million population per year.
Texas trends



TEXAS CJD TSE PRION


SATURDAY, SEPTEMBER 28, 2019 

Texas CWD TSE Prion aka Mad Deer Disease Detected Free Range Mule Deer El Paso 145 Positive To Date


*** Hartley County Sheep with Scrapie, and CWD in Hartley county ??? 

*** Friday, April 22, 2016 

*** Texas Scrapie Confirmed in a Hartley County Sheep where CWD was detected in a Mule Deer 


The 2004 enhanced BSE surveillance program was so flawed, that one of the top TSE prion Scientist for the CDC, Dr. Paul Brown stated ; Brown, who is preparing a scientific paper based on the latest two mad cow cases to estimate the maximum number of infected cows that occurred in the United States, said he has "absolutely no confidence in USDA tests before one year ago" because of the agency's reluctance to retest the Texas cow that initially tested positive.

see ;


CDC - Bovine Spongiform Encephalopathy and Variant Creutzfeldt ... Dr. Paul Brown is Senior Research Scientist in the Laboratory of Central Nervous System ... Address for correspondence: Paul Brown, Building 36, Room 4A-05, ...


PAUL BROWN COMMENT TO ME ON THIS ISSUE

Tuesday, September 12, 2006 11:10 AM

"Actually, Terry, I have been critical of the USDA handling of the mad cow issue for some years, and with Linda Detwiler and others sent lengthy detailed critiques and recommendations to both the USDA and the Canadian Food Agency."

OR, what the Honorable Phyllis Fong of the OIG found ;

Finding 2 Inherent Challenges in Identifying and Testing High-Risk Cattle Still Remain


THURSDAY, OCTOBER 22, 2015 

Former Ag Secretary Ann Veneman talks women in agriculture and we talk mad cow disease USDA and what really happened

HOW TO COVER UP MAD COW DISEASE IN TEXAS




WEDNESDAY, APRIL 24, 2019 

USDA Announces Atypical Bovine Spongiform Encephalopathy Detection Aug 29, 2018 A Review of Science 2019


SATURDAY, JUNE 1, 2019 

Traceability of animal protein byproducts in ruminants by multivariate analysis of isotope ratio mass spectrometry to prevent transmission of prion diseases


Tuesday, September 10, 2019 

FSIS [Docket No. FSIS–2019–0021] Notice of Request To Renew an Approved Information Collection: Specified Risk Materials Singeltary Submission


TUESDAY, JULY 30, 2019 

Guidelines for reporting surveillance data on Transmissible Spongiform Encephalopathies (TSE) in the EU within the framework of Regulation (EC) No 999/2001 APPROVED: 9 July 2019


PRION 2018 CONFERENCE

P98 The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge 

Greenlee JJ (1), Moore SJ (1), and West Greenlee MH (2) (1) United States Department of Agriculture, Agricultural Research Service, National Animal Disease Center, Virus and Prion Research Unit, Ames, IA, United States (2) Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, United States. 

reading up on this study from Prion 2018 Conference, very important findings ;

***> This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. 

***> These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.

PRION 2018 CONFERENCE ABSTRACT


WEDNESDAY, OCTOBER 24, 2018 

Experimental Infection of Cattle With a Novel Prion Derived From Atypical H-Type Bovine Spongiform Encephalopathy


TUESDAY, AUGUST 28, 2018 

USDA finds BSE infection in Florida cow 08/28/18 6:43 PM


WEDNESDAY, AUGUST 29, 2018 

USDA Announces Atypical Bovine Spongiform Encephalopathy Detection USDA 08/29/2018 10:00 AM EDT


WEDNESDAY, AUGUST 29, 2018 

Transmissible Spongiform Encephalopathy TSE Prion Atypical BSE Confirmed Florida Update USA August 28, 2018


MONDAY, JANUARY 09, 2017 

Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle 

CDC Volume 23, Number 2—February 2017 

*** Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.

*** Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.


THURSDAY, JULY 20, 2017 

USDA OIE Alabama Atypical L-type BASE Bovine Spongiform Encephalopathy BSE animal feeds for ruminants rule, 21 CFR 589.200


WEDNESDAY, MARCH 15, 2017 

In vitro amplification of H-type atypical bovine spongiform encephalopathy by protein misfolding cyclic amplification 

"When considering the atypical L-BSE and H-BSE diseases of cattle, they have been assessed in both non-human primate and transgenic mouse bioassays (with mice transgenic for human PRNP) and both model systems indicate that H-BSE and L-BSE may have increased zoonotic potential compare with C-BSE. 

***The detection of all types of BSE is therefore of significant importance." 


THURSDAY, JULY 20, 2017 

Alabama Mad Cow BSE


THURSDAY, JULY 20, 2017 

USDA OIE Alabama Atypical L-type BASE Bovine Spongiform Encephalopathy BSE animal feeds for ruminants rule, 21 CFR 589.200


2009 UPDATE ON ALABAMA AND TEXAS MAD COWS 2005 and 2006


Saturday, June 25, 2011

Transmissibility of BSE-L and Cattle-Adapted TME Prion Strain to Cynomolgus Macaque

"BSE-L in North America may have existed for decades"


ZOONOSIS OF SCRAPIE TSE PRION

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

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

Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases). 

Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods. 

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

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

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

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

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

=============== 

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

=============== 

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

============== 


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

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

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

 
PRION 2016 TOKYO

Saturday, April 23, 2016

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

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

Taylor & Francis

Prion 2016 Animal Prion Disease Workshop Abstracts

WS-01: Prion diseases in animals and zoonotic potential

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

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

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

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

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

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

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

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

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

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

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

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

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

snip...

R. BRADLEY



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

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

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

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


***> Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility. <***

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

Emmanuel E. Comoy, Jacqueline Mikol, Sophie Luccantoni-Freire, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Valérie Durand, Capucine Dehen, Olivier Andreoletti, Cristina Casalone, Juergen A. Richt, Justin J. Greenlee, Thierry Baron, Sylvie L. Benestad, Paul Brown & Jean-Philippe Deslys Scientific Reports volume 5, Article number: 11573 (2015) | Download Citation

Abstract 

Classical bovine spongiform encephalopathy (c-BSE) is the only animal prion disease reputed to be zoonotic, causing variant Creutzfeldt-Jakob disease (vCJD) in humans and having guided protective measures for animal and human health against animal prion diseases. Recently, partial transmissions to humanized mice showed that the zoonotic potential of scrapie might be similar to c-BSE. We here report the direct transmission of a natural classical scrapie isolate to cynomolgus macaque, a highly relevant model for human prion diseases, after a 10-year silent incubation period, with features similar to those reported for human cases of sporadic CJD. Scrapie is thus actually transmissible to primates with incubation periods compatible with their life expectancy, although fourfold longer than BSE. Long-term experimental transmission studies are necessary to better assess the zoonotic potential of other prion diseases with high prevalence, notably Chronic Wasting Disease of deer and elk and atypical/Nor98 scrapie.

SNIP...

Discussion We describe the transmission of spongiform encephalopathy in a non-human primate inoculated 10 years earlier with a strain of sheep c-scrapie. Because of this extended incubation period in a facility in which other prion diseases are under study, we are obliged to consider two alternative possibilities that might explain its occurrence. We first considered the possibility of a sporadic origin (like CJD in humans). Such an event is extremely improbable because the inoculated animal was 14 years old when the clinical signs appeared, i.e. about 40% through the expected natural lifetime of this species, compared to a peak age incidence of 60–65 years in human sporadic CJD, or about 80% through their expected lifetimes. Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.

The second possibility is a laboratory cross-contamination. Three facts make this possibility equally unlikely. First, handling of specimens in our laboratory is performed with fastidious attention to the avoidance of any such cross-contamination. Second, no laboratory cross-contamination has ever been documented in other primate laboratories, including the NIH, even between infected and uninfected animals housed in the same or adjacent cages with daily intimate contact (P. Brown, personal communication). Third, the cerebral lesion profile is different from all the other prion diseases we have studied in this model19, with a correlation between cerebellar lesions (massive spongiform change of Purkinje cells, intense PrPres staining and reactive gliosis26) and ataxia. The iron deposits present in the globus pallidus are a non specific finding that have been reported previously in neurodegenerative diseases and aging27. Conversely, the thalamic lesion was reminiscent of a metabolic disease due to thiamine deficiency28 but blood thiamine levels were within normal limits (data not shown). The preferential distribution of spongiform change in cortex associated with a limited distribution in the brainstem is reminiscent of the lesion profile in MM2c and VV1 sCJD patients29, but interspecies comparison of lesion profiles should be interpreted with caution. It is of note that the same classical scrapie isolate induced TSE in C57Bl/6 mice with similar incubation periods and lesional profiles as a sample derived from a MM1 sCJD patient30.

We are therefore confident that the illness in this cynomolgus macaque represents a true transmission of a sheep c-scrapie isolate directly to an old-world monkey, which taxonomically resides in the primate subdivision (parvorder of catarrhini) that includes humans. With an homology of its PrP protein with humans of 96.4%31, cynomolgus macaque constitutes a highly relevant model for assessing zoonotic risk of prion diseases. Since our initial aim was to show the absence of transmission of scrapie to macaques in the worst-case scenario, we obtained materials from a flock of naturally-infected sheep, affecting animals with different genotypes32. This c-scrapie isolate exhibited complete transmission in ARQ/ARQ sheep (332 ± 56 days) and Tg338 transgenic mice expressing ovine VRQ/VRQ prion protein (220 ± 5 days) (O. Andreoletti, personal communication). From the standpoint of zoonotic risk, it is important to note that sheep with c-scrapie (including the isolate used in our study) have demonstrable infectivity throughout their lymphoreticular system early in the incubation period of the disease (3 months-old for all the lymphoid organs, and as early as 2 months-old in gut-associated lymph nodes)33. In addition, scrapie infectivity has been identified in blood34, milk35 and skeletal muscle36 from asymptomatic but scrapie infected small ruminants which implies a potential dietary exposure for consumers.

Two earlier studies have reported the occurrence of clinical TSE in cynomolgus macaques after exposures to scrapie isolates. In the first study, the “Compton” scrapie isolate (derived from an English sheep) and serially propagated for 9 passages in goats did not transmit TSE in cynomolgus macaque, rhesus macaque or chimpanzee within 7 years following intracerebral challenge1; conversely, after 8 supplementary passages in conventional mice, this “Compton” isolate induced TSE in a cynomolgus macaque 5 years after intracerebral challenge, but rhesus macaques and chimpanzee remained asymptomatic 8.5 years post-exposure8. However, multiple successive passages that are classically used to select laboratory-adapted prion strains can significantly modify the initial properties of a scrapie isolate, thus questioning the relevance of zoonotic potential for the initial sheep-derived isolate. The same isolate had also induced disease into squirrel monkeys (new-world monkey)9. A second historical observation reported that a cynomolgus macaque developed TSE 6 years post-inoculation with brain homogenate from a scrapie-infected Suffolk ewe (derived from USA), whereas a rhesus macaque and a chimpanzee exposed to the same inoculum remained healthy 9 years post-exposure1. This inoculum also induced TSE in squirrel monkeys after 4 passages in mice. Other scrapie transmission attempts in macaque failed but had more shorter periods of observation in comparison to the current study. Further, it is possible that there are differences in the zoonotic potential of different scrapie strains.

The most striking observation in our study is the extended incubation period of scrapie in the macaque model, which has several implications. Firstly, our observations constitute experimental evidence in favor of the zoonotic potential of c-scrapie, at least for this isolate that has been extensively studied32,33,34,35,36. The cross-species zoonotic ability of this isolate should be confirmed by performing duplicate intracerebral exposures and assessing the transmissibility by the oral route (a successful transmission of prion strains through the intracerebral route may not necessarily indicate the potential for oral transmission37). However, such confirmatory experiments may require more than one decade, which is hardly compatible with current general management and support of scientific projects; thus this study should be rather considered as a case report.

Secondly, transmission of c-BSE to primates occurred within 8 years post exposure for the lowest doses able to transmit the disease (the survival period after inoculation is inversely proportional to the initial amount of infectious inoculum). The occurrence of scrapie 10 years after exposure to a high dose (25 mg) of scrapie-infected sheep brain suggests that the macaque has a higher species barrier for sheep c-scrapie than c-BSE, although it is notable that previous studies based on in vitro conversion of PrP suggested that BSE and scrapie prions would have a similar conversion potential for human PrP38.

Thirdly, prion diseases typically have longer incubation periods after oral exposure than after intracerebral inoculations: since humans can develop Kuru 47 years after oral exposure39, an incubation time of several decades after oral exposure to scrapie would therefore be expected, leading the disease to occur in older adults, i.e. the peak age for cases considered to be sporadic disease, and making a distinction between scrapie-associated and truly sporadic disease extremely difficult to appreciate.

Fourthly, epidemiologic evidence is necessary to confirm the zoonotic potential of an animal disease suggested by experimental studies. A relatively short incubation period and a peculiar epidemiological situation (e.g., all the first vCJD cases occurring in the country with the most important ongoing c-BSE epizootic) led to a high degree of suspicion that c-BSE was the cause of vCJD. Sporadic CJD are considered spontaneous diseases with an almost stable and constant worldwide prevalence (0.5–2 cases per million inhabitants per year), and previous epidemiological studies were unable to draw a link between sCJD and classical scrapie6,7,40,41, even though external causes were hypothesized to explain the occurrence of some sCJD clusters42,43,44. However, extended incubation periods exceeding several decades would impair the predictive values of epidemiological surveillance for prion diseases, already weakened by a limited prevalence of prion diseases and the multiplicity of isolates gathered under the phenotypes of “scrapie” and “sporadic CJD”.

Fifthly, considering this 10 year-long incubation period, together with both laboratory and epidemiological evidence of decade or longer intervals between infection and clinical onset of disease, no premature conclusions should be drawn from negative transmission studies in cynomolgus macaques with less than a decade of observation, as in the aforementioned historical transmission studies of scrapie to primates1,8,9. Our observations and those of others45,46 to date are unable to provide definitive evidence regarding the zoonotic potential of CWD, atypical/Nor98 scrapie or H-type BSE. The extended incubation period of the scrapie-affected macaque in the current study also underscores the limitations of rodent models expressing human PrP for assessing the zoonotic potential of some prion diseases since their lifespan remains limited to approximately two years21,47,48. This point is illustrated by the fact that the recently reported transmission of scrapie to humanized mice was not associated with clinical signs for up to 750 days and occurred in an extreme minority of mice with only a marginal increase in attack rate upon second passage13. The low attack rate in these studies is certainly linked to the limited lifespan of mice compared to the very long periods of observation necessary to demonstrate the development of scrapie. Alternatively, one could estimate that a successful second passage is the result of strain adaptation to the species barrier, thus poorly relevant of the real zoonotic potential of the original scrapie isolate of sheep origin49. The development of scrapie in this primate after an incubation period compatible with its lifespan complements the study conducted in transgenic (humanized) mice; taken together these studies suggest that some isolates of sheep scrapie can promote misfolding of the human prion protein and that scrapie can develop within the lifespan of some primate species.

In addition to previous studies on scrapie transmission to primate1,8,9 and the recently published study on transgenic humanized mice13, our results constitute new evidence for recommending that the potential risk of scrapie for human health should not be dismissed. Indeed, human PrP transgenic mice and primates are the most relevant models for investigating the human transmission barrier. To what extent such models are informative for measuring the zoonotic potential of an animal TSE under field exposure conditions is unknown. During the past decades, many protective measures have been successfully implemented to protect cattle from the spread of c-BSE, and some of these measures have been extended to sheep and goats to protect from scrapie according to the principle of precaution. Since cases of c-BSE have greatly reduced in number, those protective measures are currently being challenged and relaxed in the absence of other known zoonotic animal prion disease. We recommend that risk managers should be aware of the long term potential risk to human health of at least certain scrapie isolates, notably for lymphotropic strains like the classical scrapie strain used in the current study. Relatively high amounts of infectivity in peripheral lymphoid organs in animals infected with these strains could lead to contamination of food products produced for human consumption. Efforts should also be maintained to further assess the zoonotic potential of other animal prion strains in long-term studies, notably lymphotropic strains with high prevalence like CWD, which is spreading across North America, and atypical/Nor98 scrapie (Nor98)50 that was first detected in the past two decades and now represents approximately half of all reported cases of prion diseases in small ruminants worldwide, including territories previously considered as scrapie free... Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.


hronic Wasting Disease In Cervids: Zoonosis there from, has it already happened, and is it being misdiagnosed as sporadic cjd?

> However, to date, no CWD infections have been reported in people.
key word here is ‘reported’. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can’t, and it’s as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it’s being misdiagnosed as sporadic CJD. …terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***
Chronic Wasting Disease CWD TSE Prion aka mad deer disease zoonosis
We hypothesize that:
(1) The classic CWD prion strain can infect humans at low levels in the brain and peripheral lymphoid tissues;
(2) The cervid-to-human transmission barrier is dependent on the cervid prion strain and influenced by the host (human) prion protein (PrP) primary sequence;
(3) Reliable essays can be established to detect CWD infection in humans; and
(4) CWD transmission to humans has already occurred. We will test these hypotheses in 4 Aims using transgenic (Tg) mouse models and complementary in vitro approaches.
ZOONOTIC CHRONIC WASTING DISEASE CWD TSE PRION UPDATE
Prion 2017 Conference
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1 
University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen 
This is a progress report of a project which started in 2009. 21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves. 
Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice. 
At present, a total of 10 animals are sacrificed and read-outs are ongoing. Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10 years. Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation. 
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS 
PRION 2018 CONFERENCE
Oral transmission of CWD into Cynomolgus macaques: signs of atypical disease, prion conversion and infectivity in macaques and bio-assayed transgenic mice
Hermann M. Schatzl, Samia Hannaoui, Yo-Ching Cheng, Sabine Gilch (Calgary Prion Research Unit, University of Calgary, Calgary, Canada) Michael Beekes (RKI Berlin), Walter Schulz-Schaeffer (University of Homburg/Saar, Germany), Christiane Stahl-Hennig (German Primate Center) & Stefanie Czub (CFIA Lethbridge).
To date, BSE is the only example of interspecies transmission of an animal prion disease into humans. The potential zoonotic transmission of CWD is an alarming issue and was addressed by many groups using a variety of in vitro and in vivo experimental systems. Evidence from these studies indicated a substantial, if not absolute, species barrier, aligning with the absence of epidemiological evidence suggesting transmission into humans. Studies in non-human primates were not conclusive so far, with oral transmission into new-world monkeys and no transmission into old-world monkeys. Our consortium has challenged 18 Cynomolgus macaques with characterized CWD material, focusing on oral transmission with muscle tissue. Some macaques have orally received a total of 5 kg of muscle material over a period of 2 years.
After 5-7 years of incubation time some animals showed clinical symptoms indicative of prion disease, and prion neuropathology and PrPSc deposition were detected in spinal cord and brain of some euthanized animals. PrPSc in immunoblot was weakly detected in some spinal cord materials and various tissues tested positive in RT-QuIC, including lymph node and spleen homogenates. To prove prion infectivity in the macaque tissues, we have intracerebrally inoculated 2 lines of transgenic mice, expressing either elk or human PrP. At least 3 TgElk mice, receiving tissues from 2 different macaques, showed clinical signs of a progressive prion disease and brains were positive in immunoblot and RT-QuIC. Tissues (brain, spinal cord and spleen) from these and pre-clinical mice are currently tested using various read-outs and by second passage in mice. Transgenic mice expressing human PrP were so far negative for clear clinical prion disease (some mice >300 days p.i.). In parallel, the same macaque materials are inoculated into bank voles.
Taken together, there is strong evidence of transmissibility of CWD orally into macaques and from macaque tissues into transgenic mouse models, although with an incomplete attack rate.
The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology.
Our ongoing studies will show whether the transmission of CWD into macaques and passage in transgenic mice represents a form of non-adaptive prion amplification, and whether macaque-adapted prions have the potential to infect mice expressing human PrP.
The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD..
***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD. <***
READING OVER THE PRION 2018 ABSTRACT BOOK, LOOKS LIKE THEY FOUND THAT from this study ;
P190 Human prion disease mortality rates by occurrence of chronic wasting disease in freeranging cervids, United States
Abrams JY (1), Maddox RA (1), Schonberger LB (1), Person MK (1), Appleby BS (2), Belay ED (1) (1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA..
SEEMS THAT THEY FOUND Highly endemic states had a higher rate of prion disease mortality compared to non-CWD
states.
AND ANOTHER STUDY;
P172 Peripheral Neuropathy in Patients with Prion Disease
Wang H(1), Cohen M(1), Appleby BS(1,2) (1) University Hospitals Cleveland Medical Center, Cleveland, Ohio (2) National Prion Disease Pathology Surveillance Center, Cleveland, Ohio..
IN THIS STUDY, THERE WERE autopsy-proven prion cases from the National Prion Disease Pathology Surveillance Center that were diagnosed between September 2016 to March 2017,
AND
included 104 patients. SEEMS THEY FOUND THAT The most common sCJD subtype was MV1-2 (30%), followed by MM1-2 (20%),
AND
THAT The Majority of cases were male (60%), AND half of them had exposure to wild game.
snip…
see more on Prion 2017 Macaque study from Prion 2017 Conference and other updated science on cwd tse prion zoonosis below…terry
PRION 2019 ABSTRACTS 

1. Interspecies transmission of the chronic wasting disease agent

Justin Greenlee

Virus and Prion Research Unit, National Animal Disease Center, USDA Agriculture Research Service

ABSTRACT

The presentation will summarize the results of various studies conducted at our research center that assess the transmissibility of the chronic wasting disease (CWD) agent to cattle, pigs, raccoons, goats, and sheep. This will include specifics of the relative attack rates, clinical signs, and microscopic lesions with emphasis on how to differentiate cross-species transmission of the CWD agent from the prion diseases that naturally occur in hosts such as cattle or sheep. Briefly, the relative difficulty of transmitting the CWD agent to sheep and goats will be contrasted with the relative ease of transmitting the scrapie agent to white-tailed deer.

53. Evaluation of the inter-species transmission potential of different CWD isolates

Rodrigo Moralesa, Carlos Kramma,b, Paulina Sotoa, Adam Lyona, Sandra Pritzkowa, Claudio Sotoa

aMitchell Center for Alzheimer’s disease and Related Brain Disorders, Dept. of Neurology, McGovern School of Medicine University of Texas Health Science Center at Houston, TX, USA; bFacultad de Medicina, Universidad de los Andes, Santiago, Chile

ABSTRACT

Chronic Wasting Disease (CWD) has reached epidemic proportions in North America and has been identified in South Korea and Northern Europe. CWD-susceptible cervid species are known to share habitats with humans and other animals entering the human food chain. At present, the potential of CWD to infect humans and other animal species is not completely clear. The exploration of this issue acquires further complexity considering the differences in the prion protein sequence due to species-specific variations and polymorphic changes within species. While several species of cervids are naturally affected by CWD, white-tailed deer (WTD) is perhaps the most relevant due to its extensive use in hunting and as a source of food. Evaluation of inter-species prion infections using animals or mouse models is costly and time consuming. We and others have shown that the Protein Misfolding Cyclic Amplification (PMCA) technology reproduces, in an accelerated and inexpensive manner, the inter-species transmission of prions while preserving the strain features of the input PrPSc. In this work, we tested the potential of different WTD-derived CWD isolates to transmit to humans and other animal species relevant for human consumption using PMCA. For these experiments, CWD isolates homozygous for the most common WTD-PrP polymorphic changes (G96S) were used (96SS variant obtained from a pre-symptomatic prion infected WTD). Briefly, 96GG and 96SS CWD prions were adapted in homologous or heterologous substrate by PMCA through several (15) rounds. End products, as well as intermediates across the process, were tested for their inter-species transmission potentials. A similar process was followed to assess seed-templated misfolding of ovine, porcine, and bovine PrPC. Our results show differences on the inter-species transmission potentials of the four adapted materials generated (PrPC/PrPSc polymorphic combinations), being the homologous combinations of seed/substrate the ones with the greater apparent zoonotic potential. Surprisingly, 96SS prions adapted in homologous substrate were the ones showing the easiest potential to template PrPC misfolding from other animal species. In summary, our results show that a plethora of different CWD isolates, each comprising different potentials for inter-species transmission, may exist in the environment. These experiments may help to clarify an uncertain and potentially worrisome public health issue. Additional research in this area may be useful to advise on the design of regulations intended to stop the spread of CWD and predict unwanted zoonotic events.

56. Understanding chronic wasting disease spread potential for at-risk species

Catherine I. Cullingham, Anh Dao, Debbie McKenzie and David W. Coltman

Department of Biological Sciences, University of Alberta, Edmonton AB, Canada

CONTACT Catherine I. Cullingham cathy.cullingham@ualberta.ca

ABSTRACT

Genetic variation can be linked to susceptibility or resistance to a disease, and this information can help to better understand spread-risk in a population. Wildlife disease incidence is increasing, and this is resulting in negative impacts on the economy, biodiversity, and in some instances, human health. If we can find genetic variation that helps to inform which individuals are susceptible, then we can use this information on at-risk populations to better manage negative consequences. Chronic wasting disease, a fatal, transmissible spongiform encephalopathy of cervids (both wild and captive), continues to spread geographically, which has resulted in an increasing host-range. The disease agent (PrPCWD) is a misfolded conformer of native cellular protein (PrPC). In Canada, the disease is endemic in Alberta and Saskatchewan, infecting primarily mule deer and white-tail deer, with a smaller impact on elk and moose populations. As the extent of the endemic area continues to expand, additional species will be exposed to this disease, including bison, bighorn sheep, mountain goat, and pronghorn antelope. To better understand the potential spread-risk among these species, we reviewed the current literature on species that have been orally exposed to CWD to identify susceptible and resistant species. We then compared the amino acid polymorphisms of PrPC among these species to determine whether any sites were linked to susceptibility or resistance to CWD infection. We sequenced the entire PrP coding region in 578 individuals across at-risk populations to evaluate their potential susceptibility. Three amino acid sites (97, 170, and 174; human numbering) were significantly associated with susceptibility, but these were not fully discriminating. All but one species among the resistant group shared the same haplotype, and the same for the susceptible species. For the at-risk species, bison had the resistant haplotype, while bighorn sheep and mountain goats were closely associated with the resistant type. Pronghorn antelope and a newly identified haplotype in moose differed from the susceptible haplotype, but were still closely associated with it. These data suggest pronghorn antelope will be susceptible to CWD while bison are likely to be resistant. Based on this data, recommendations can be made regarding species to be monitored for possible CWD infection.

KEYWORDS: Chronic wasting disease; Prnp; wildlife disease; population genetics; ungulates

Thursday, May 23, 2019 

Prion 2019 Emerging Concepts CWD, BSE, SCRAPIE, CJD, SCIENTIFIC PROGRAM Schedule and Abstracts


see full Prion 2019 Conference Abstracts

THURSDAY, OCTOBER 04, 2018
Cervid to human prion transmission 5R01NS088604-04 Update
snip…full text;
SATURDAY, FEBRUARY 09, 2019
Experts: Yes, chronic wasting disease in deer is a public health issue — for people
FRIDAY, JULY 26, 2019 

Chronic Wasting Disease in Cervids: Implications for Prion Transmission to Humans and Other Animal Species


MONDAY, FEBRUARY 25, 2019

MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019


WEDNESDAY, JULY 31, 2019 

The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L


***> cattle, pigs, sheep, cwd, tse, prion, oh my!

***> In contrast, cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions but no natural CWD infections in cattle have been reported (Sigurdson, 2008; Hamir et al., 2006). 

Sheep and cattle may be exposed to CWD via common grazing areas with affected deer but so far, appear to be poorly susceptible to mule deer CWD (Sigurdson, 2008). In contrast, cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions but no natural CWD infections in cattle have been reported (Sigurdson, 2008; Hamir et al., 2006). It is not known how susceptible humans are to CWD but given that the prion can be present in muscle, it is likely that humans have been exposed to the agent via consumption of venison (Sigurdson, 2008). Initial experimental research suggests that human susceptibility to CWD is low and there may be a robust species barrier for CWD transmission to humans (Sigurdson, 2008), however the risk appetite for a public health threat may still find this level unacceptable.



cwd scrapie pigs oral routes

***> However, at 51 months of incubation or greater, 5 animals were positive by one or more diagnostic methods. Furthermore, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study) suggesting that swine are potential hosts for the agent of scrapie. <*** 

 >*** Although the current U.S. feed ban is based on keeping tissues from TSE infected cattle from contaminating animal feed, swine rations in the U.S. could contain animal derived components including materials from scrapie infected sheep and goats. These results indicating the susceptibility of pigs to sheep scrapie, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health. <*** 

***> Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 month group was positive by EIA. PrPSc was detected by QuIC in at least one of the lymphoid tissues examined in 5/6 pigs in the intracranial <6 months group, 6/7 intracranial >6 months group, 5/6 pigs in the oral <6 months group, and 4/6 oral >6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%). 

***> Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. 

This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. 

Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains. 




Friday, December 14, 2012

DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012

snip.....

In the USA, under the Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law.

Animals considered at high risk for CWD include:

1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and

2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.

Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.

The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES. It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.

Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.

There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.

snip.....

36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011).

The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE).

Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison.

snip.....

The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).

snip.....

In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion.

snip.....

In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible... For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.

snip.....

Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.

snip.....


READ THIS VERY, VERY, CAREFULLY;

SUNDAY, SEPTEMBER 1, 2019 

***> FDA Reports on VFD Compliance


TUESDAY, APRIL 18, 2017 

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

THURSDAY, SEPTEMBER 26, 2019 

Veterinary Biologics Guideline 3.32E: Guideline for minimising the risk of introducing transmissible spongiform encephalopathy prions and other infectious agents through veterinary biologics


SATURDAY, SEPTEMBER 21, 2019 

National Variability in Prion Disease–Related Safety Policies for Neurologic Procedures



Friday, September 27, 2019

Prion disease and recommended procedures for flexible endoscope reprocessing – a review of policies worldwide and proposal for a simplified approach


Terry S. Singeltary Sr.

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