Discrimination of Classical and Atypical BSE by a Distinct Immunohistochemical PrPSc Profile.
Fast C1, Graham C2, Kaatz M3, Santiago-Mateo K2, Kaatz T2, MacPherson K3, Balkema-Buschmann A1, Ziegler U1, Groschup MH1, Czub S2 Author information
Pathogens (Basel, Switzerland), 20 Feb 2023, 12(2):353
DOI: 10.3390/pathogens12020353 PMID: 36839625 PMCID: PMC9965285
Free to read & use
Abstract
Bovine spongiform encephalopathy (BSE) belongs to the group of transmissible spongiform encephalopathies and is associated with the accumulation of a pathological isoform of the host-encoded glycoprotein, designated prion protein (PrPSc). Classical BSE (C-type) and two atypical BSE forms (L- and H-type) are known, and can be discriminated by biochemical characteristics. The goal of our study was to identify type-specific PrPSc profiles by using Immunohistochemistry. In our study, brain samples from 21 cattle, intracerebrally inoculated with C-, H-, and L-type BSE, were used. In addition, the corresponding samples from three orally C-type BSE infected animals were also included. From all animals, a lesion and PrPSc-profiles of six brain regions were determined. The lesion profile and the neuroanatomical distribution of PrPSc was highly consistent between the groups, but the immunohistochemical analysis revealed a distinct PrPSc profile for the different BSE-types, which included both the topographic and cellular pattern of PrPSc. This qualitative and quantitative analysis of PrPSc affected structures sheds new light into the pathogenesis of the different BSE types. Furthermore, immunohistochemical characterization is supported as an additional diagnostic tool in BSE surveillance programs, especially when only formalin-fixed tissue samples are available.
1. Introduction
Transmissible spongiform encephalopathies (TSE) are a complex group of chronic fatal neurodegenerative disorders, which include genetic, infectious, and sporadic diseases in several species, including humans. In all TSEs the host-encoded cellular prion protein (PrPC) is converted into a stable, partially protease-resistant pathological isoform (PrPSc), which accumulates over time and is the diagnostic disease marker detectable by immunohistochemistry (IHC) and biochemically [1].
In contrast to scrapie in sheep, the prototype of all TSE, which has been known since more than 270 years [2], bovine spongiform encephalopathy (BSE), was not diagnosed until 1986 [3]. This so-called classical BSE (“C-type”) originated from oral uptake of infectious feedstuff and, during the BSE epidemic, affected more than 185.000 clinically and fatally diseased cattle worldwide [4]. In 1997, the zoonotic nature of C-type BSE, causing variant Creutzfeldt Jacob disease, was described [5].
The active BSE surveillance program in the European Union revealed two additional atypical BSE types in 2004, the so-called “H-type” in France [6] and an “L-type” BSE in Italy [7]. Pathological, molecular, and biological phenotypes of these unusual BSE types differ from C-type BSE, and in particular the molecular signature has been welldescribed and is used for TSE classification [6–8]. Atypical BSE occurs worldwide in older cattle (average age at detection 12.05 years) and numbers of detected animals seem to be unchanging, with 1–2 cases per million in tested bovines over eight years of age [9,10]. These epidemiological data led to the hypothesis that atypical BSE belongs to the group of spontaneously arising TSEs [9].
TSEs are characterized pathologically by degenerative changes in grey matter, including spongiform changes of neuropil, vacuoles within neuronal perikarya, and an astrocytic response. The detection of amyloid plaques is variable and depends on the TSE form [11]. While vacuolar lesion profiles in the brains of conventional mice inoculated with different TSE strains have been successfully used for strain typing purposes [5,12], lesion profiles in natural scrapie cases in sheep are highly variable and influenced not only by the host genotype but also by other yet-unknown factors [13–15]. Interestingly, for C-type BSE, several studies from different countries indicate a highly stable strain [16–20]. Unfortunately, almost all atypical BSE cases are fallen stock, therefore suitable material for performing a lesion profile is rather limited and the few results are insufficient for a comparative study [7,21–23]. On the other hand, the results of intracerebral studies are difficult to compare, because these studies frequently included different disease time points, at which the animals were sacrificed and different brain regions were used for analysis, in addition to being interpreted by various readers. Nevertheless, there is evidence of differences in the distribution of lesions between BSE types in specific brain regions, e.g., forebrain or cerebellum [24–31] (see literature review in supplemental Table S1).
General characteristic for all TSEs is the massive accumulation of PrPSc in the central nervous system of clinically diseased animals. Over the years, differences in the neuroanatomical distribution, as well as the existence of several morphological PrPSc types, had been demonstrated by immunohistochemistry, the most variable in classical scrapie cases [32]. These patterns include cell-membrane/extracellular PrPSc types, i.e., neuropilassociated (linear, fine, or coarse particulate, coalescing, perineuronal), glial-cell associated (stellate, perivacuolar, subpial, subependymal, perivascular), ependymal-cell associated (supraependymal) and endothelium associated (vascular plaques) PrPSc depositions. Extracellular plaque-like accumulations of PrPSc have also been described. Furthermore, intracellular accumulation has also been reported with intraneuronal, intra-astrocytic, and intraglial accumulations [32,33]. These patterns are considered to be linked to cell tropism and PrPSc processing and had been useful in characterizing scrapie strains in the natural hosts [34–36].
In addition, transgenic mice and bank voles inoculated with TSE isolates are increasingly being subjected to PrPSc profiling to characterize TSE strains [37–39]. PrPSc profiles of different brain regions have already been described for all BSE types [7,8,19,22–31,40–47], but a systematic comparison between these studies is even more complicated than for the lesion profile because of the numerous variables (i.e., PrPSc types, available brain regions, grading, readers); moreover, the published results also contradict each other (see literature review in Supplemental Tables S2 and S3). However, there are indications that some differences in the PrPSc profile, particularly in the cerebrum and cerebellum, may exist [7,24,29,30].
In total, 144 atypical BSE cases have been confirmed worldwide since 2001, and the yearly numbers of reported H- and L-type BSE cases have been stable over the years [10]. These statistics indicate that atypical BSE will not decline over the years, as was the case with C-type BSE. Atypical BSE is able to cross the species barrier to several experimentally challenged animals and an aetiological relationship between atypical and C-type BSE is still not finally clarified [9]. Therefore, in 2013, Regulation (EC) No. 999/2001 was amended, requiring that the BSE type be identified in BSE-confirmed samples in the European Union and elsewhere. This discriminatory testing relies solely on the molecular signature of the BSE types, which includes the determination of the protease-resistant size and the glycosylation pattern of PrPSc [6–8]. However, these techniques are not established in all National Reference Laboratories, and the availability of native reference material of atypical BSE is scarce and rapidly declining. Moreover, situations may arise where native material is not available (current or retrospective) or biochemical analysis yields unclear results. An additional tool to distinguish the case in question is then very helpful. Therefore, we report here a comparative systematic histopathological and immunohistochemical study of the brains of intracerebral C-, H-, and L-type BSE-infected cattle. For comparison, we included orally with C-type BSE infected animals. The results presented clearly indicate the discriminatory potential of tissue samples fixed in formalin, which will be useful to support future BSE classification efforts, in particular in cases where no frozen material is available.
2. Materials and Methods
All animals used in this study showed clinical signs of BSE and have been confirmed as BSE-positive by IHC and/or immunoblot. In Table 1, the most important details of the animal experiments are summarized.
Table 1. Details of cattle intracerebrally inoculated at the FLI/Germany and CFIA/Canada with C-, H- and L-type BSE.
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5. Conclusions
Our systematic examination of the PrPSc profiles of the C-, H-, and L-type BSE showed clear qualitative differences in a selection of neuroanatomical structures, which includes all parts of the brain and can easily be used for an additional discriminatory purpose. In brief:
• C-type BSE showed the most variable PrPSc profile with a distinct tendency for a stellate pattern, which is particularly obvious in the multifocal distribution pattern found in the cerebellar cortex. In addition, hypoglossal nucleus revealed clear intraneuronal PrPSc accumulation, the central parts of the hippocampal hilus were massively affected even with unique plaque-like formations, and in the molecular layer of the cerebrum, PrPSc accumulations seemed to be associated with Cajal horizontal cells, forming a tape-like pattern.
• H-type BSE showed a characteristic strong intramicroglial PrPSc accumulation pattern throughout the brain, which is mostly associated with a fine particular staining reaction of the neuropil. In the hypoglossal nucleus an intraneuronal staining reaction was obvious, while in the hilus of the hippocampus, PrPSc accumulation was mostly confined to peripheral neuronal cells. Moreover, in the molecular layer of cerebrum, a PrPSc tape-like pattern is evident.
• L-type BSE revealed a mostly fine particulate and diffuse PrPSc accumulation in the neuropil in the molecular layers of the cerebellum and cerebrum. In the cerebrum, large plaque-like formations were frequently found, and in the granular layer of cerebellum, a unique perineuronal staining reaction was visible, while an intraneuronal PrPSc deposition in hypoglossal nucleus was missing.
It has to be kept in mind that most BSE cases are diagnosed in fallen stock animals, and whole brains will only be available in exceptional cases for further studies. Further studies should therefore focus on the liability of the discrimination scheme presented, using available samples from field cases. In any case, however, considering our results and in agreement with previous studies [30], we highly recommend including not only brainstem but also cerebellum in routine surveillance sampling. As demonstrated by the long-standing sampling procedure for the detection of TSE in small ruminants, this can be readily done through the Foramen magnum and could be used as an additional diagnostic tool to support the differentiation of BSE types.
Supplementary Materials: The following supporting information can be downloaded at:
Table S1: Lesion profiles in different brain regions of C-, H- and L-type BSE infected cattle (literature review); Table S2: PrPSc profiles in brainstem described in literature for C-, H- and L-type BSE infected cattle (literature review); Table S3: PrPSc profiles in different brain regions described in literature for C-, H- and L-type BSE infected cattle (literature review); Figure S1: Schematic overview of the brain regions examined; Figure S2: Most important immunohistochemical reaction pattern used for conducting the PrPSc profiles; Figure S3: Lesion profiles of cattle intracerebrally infected with C-, H- and L-type BSE and comparison of lesion profiles of intracerebrally and orally infected groups; Figure S4: Comparison of the general amount of PrPSc accumulation in intracerebral infected C-, H- and L-type BSE cases and in oral versus intracerebral infected C-type BSE cases.
see full text;
i would kindly like to elaborate on risk factors for feed from atypical BSE, and the infamous 'spontaneous' theory, please;
This so-called classical BSE (“C-type”) originated from oral uptake of infectious feedstuff and, during the BSE epidemic, affected more than 185.000 clinically and fatally diseased cattle worldwide [4]. In 1997, the zoonotic nature of C-type BSE, causing variant Creutzfeldt Jacob disease, was described [5].
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Atypical BSE occurs worldwide in older cattle (average age at detection 12.05 years) and numbers of detected animals seem to be unchanging, with 1–2 cases per million in tested bovines over eight years of age [9,10]. These epidemiological data led to the hypothesis that atypical BSE belongs to the group of spontaneously arising TSEs [9].
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1st, let's discuss the SPONTANEOUS ATYPICAL H-TYPE BSE OUTBREAK IN FRANCE.
FRANCE Farmers fear new ‘mad cow’ scare
March 23, 2016
POSSIBLE mad cow disease has been found on a farm in Ardennes and farmers fear beef sales will be hard hit if the disease is confirmed. If confirmed, it would be the first case of Bovine spongiform encephalitis in France since 2004. The transmissible neurodegenerative disease kills cattle and has been linked to the incurable variant Creutzfeldt-Jakob disease in humans, which destroys brain tissue.
There were more than 185,000 confirmed cases of BSE in Europe and especially the UK in the 1980s and 90s and more than four million cattle were killed and burned. It was thought to have been caused by animal feed that contained the remains of infected animals. The UK has had 177 confirmed cases of the human vCJD since the mid-1980s.
Vets at a rendering plant discovered traces of what they suspected was BSE in a Salers cow sent to the knackers yard after dying on a farm near Rethel in Ardennes in north-eastern France. Animals which die on farms are deemed unfit for consumption and sent to the knackers for inspection to find the cause of death. Now samples have been sent to the official European BSE reference laboratory in the UK for confirmation of the disease and the farmer’s 400 other animals have been quarantined.
Confirmation will take up to 10 days and all animals in contact with the cow will be slaughtered, along with those from the same birth line as inheritance is the only known method of transmission. Staff from the Direction Générale de l'Alimentation are already tracing these animals but made it clear that not all animals on linked farms would be killed. Farmers across the industry have been hard hit by falling incomes and have launched widescale protests demanding action.
This new threat, coming just months after France won back its "negligible risk" rating for BSE could put the beef sector in great difficulty if it returns to the “controlled risk” status. Countries such as South Africa, Saudi Arabia, Vietnam and Singapore lifted their embargo on French beef after it became negligible risk. The possible effects of more BSE cases were shown in the UK, where domestic beef sales fell 40% in the 1990s and sales were banned across the EU, led by France.
Salers cattle photo: Fabien1309 CC BY-SA 3.0 -
***atypical spontaneous BSE in France LOL***
FRANCE STOPS TESTING FOR MAD COW DISEASE BSE, and here’s why, to many spontaneous events of mad cow disease $$$
***so 20 cases of atypical BSE in France, compared to the remaining 40 cases in the remaining 12 Countries, divided by the remaining 12 Countries, about 3+ cases per country, besides Frances 20 cases. you cannot explain this away with any spontaneous BSe. ...TSS
Sunday, October 5, 2014
France stops BSE testing for Mad Cow Disease
Thursday, June 05, 2008
Review on the epidemiology and dynamics of BSE epidemics
Vet. Res. (2008) 39:15 www.vetres.org DOI: 10.1051/vetres:2007053 c INRA, EDP Sciences, 2008 Review article
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And last but not least, similarities of PrPres between Htype BSE and human prion diseases like CJD or GSS have been put forward [10], as well as between L-type BSE and CJD [17]. These findings raise questions about the origin and inter species transmission of these prion diseases that were discovered through the BSE active surveillance.
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Cases of atypical BSE have only been found in countries having implemented large active surveillance programs. As of 1st September 2007, 36 cases (16 H, 20 L) have been described all over the world in cattle: Belgium (1 L) [23], Canada (1 H)15, Denmark (1 L)16, France (8 H, 6 L)17, Germany (1 H, 1 L) [13], Italy (3 L)18, Japan (1 L) [71], Netherlands (1 H, 2 L)19, Poland (1 H, 6 L)20, Sweden (1 H)21, United Kingdom (1 H)22, and USA (2 H)23. Another H-type case has been found in a 19 year old miniature zebu in a zoological park in Switzerland [56]. It is noteworthy that atypical cases have been found in countries that did not experience classical BSE so far, like Sweden, or in which only few cases of classical BSE have been found, like Canada or the USA.
And last but not least, similarities of PrPres between Htype BSE and human prion diseases like CJD or GSS have been put forward [10], as well as between L-type BSE and CJD [17]. These findings raise questions about the origin and inter species transmission of these prion diseases that were discovered through the BSE active surveillance.
full text 18 pages ;
lot of spontaneous mutations of atypical BSE in France? no? Feed?
2ND, WHAT HAS THE OIE ET AL SAID ABOUT ATYPICAL BSE NOW;
''As a result, since atypical BSE can be reasonably considered to pose a potential background level of risk for any country with cattle, the recycling of both classical and atypical strains in the cattle and broader ruminant populations should be avoided.''
OIE Conclusions on transmissibility of atypical BSE among cattle
Given that cattle have been successfully infected by the oral route, at least for L-BSE, it is reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle are exposed to contaminated feed. In addition, based on reports of atypical BSE from several countries that have not had C-BSE, it appears likely that atypical BSE would arise as a spontaneous disease in any country, albeit at a very low incidence in old cattle. In the presence of livestock industry practices that would allow it to be recycled in the cattle feed chain, it is likely that some level of exposure and transmission may occur. As a result, since atypical BSE can be reasonably considered to pose a potential background level of risk for any country with cattle, the recycling of both classical and atypical strains in the cattle and broader ruminant populations should be avoided.
''the Group was of the opinion that it would be reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle were to be exposed to contaminated feed. Therefore, the recycling of atypical strains in cattle and broader ruminant populations should be avoided.''
Annex 7 (contd) AHG on BSE risk assessment and surveillance/March 2019
34 Scientific Commission/September 2019
3. Atypical BSE
The Group discussed and endorsed with minor revisions an overview of relevant literature on the risk of atypical BSE being recycled in a cattle population and its zoonotic potential that had been prepared ahead of the meeting by one expert from the Group. This overview is provided as Appendix IV and its main conclusions are outlined below. With regard to the risk of recycling of atypical BSE, recently published research confirmed that the L-type BSE prion (a type of atypical BSE prion) may be orally transmitted to calves1 . In light of this evidence, and the likelihood that atypical BSE could arise as a spontaneous disease in any country, albeit at a very low incidence, the Group was of the opinion that it would be reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle were to be exposed to contaminated feed. Therefore, the recycling of atypical strains in cattle and broader ruminant populations should be avoided.
The Group acknowledged the challenges in demonstrating the zoonotic transmission of atypical strains of BSE in natural exposure scenarios. Overall, the Group was of the opinion that, at this stage, it would be premature to reach a conclusion other than that atypical BSE poses a potential zoonotic risk that may be different between atypical strains.
4. Definitions of meat-and-bone meal (MBM) and greaves
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REFERENCES
SNIP...END SEE FULL TEXT;
''H-TYPE BSE AGENT IS TRANSMISSIBLE BY THE ORONASAL ROUTE''
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.
Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
Thus, it is imperative to maintain measures that prevent the entry of tissues from cattle possibly infected with the agent of L-BSE into the food chain.
IT is imperative that the USA puts forth immediately a MANDATORY National Animal Identification System and Country Of Origin Labeling System, for the sake of livestock industry and the consumers that consume their products...terry
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 longe 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.
2.3.2. New evidence on the zoonotic potential of atypical BSE and atypical scrapie prion strains
Olivier Andreoletti, INRA Research Director, Institut National de la Recherche Agronomique (INRA) – École Nationale Vétérinaire de Toulouse (ENVT), invited speaker, presented the results of two recently published scientific articles of interest, of which he is co-author:
‘Radical Change in Zoonotic Abilities of Atypical BSE Prion Strains as Evidenced by Crossing of Sheep Species Barrier in Transgenic Mice’ (MarinMoreno et al., 2020) and ‘The emergence of classical BSE from atypical/Nor98 scrapie’ (Huor et al., 2019).
In the first experimental study, H-type and L-type BSE were inoculated into transgenic mice expressing all three genotypes of the human PRNP at codon 129 and into adapted into ARQ and VRQ transgenic sheep mice. The results showed the alterations of the capacities to cross the human barrier species (mouse model) and emergence of sporadic CJD agents in Hu PrP expressing mice: type 2 sCJD in homozygous TgVal129 VRQ-passaged L-BSE, and type 1 sCJD in homozygous TgVal 129 and TgMet129 VRQ-passaged H-BSE.
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.
WAHIS, WOAH, OIE, REPORT United Kingdom Bovine Spongiform Encephalopathy Atypical H-Type
United Kingdom - Bovine spongiform encephalopathy - Immediate notification
WAHIS, WOAH, OIE, REPORT Switzerland Bovine Spongiform Encephalopathy Atypical L-Type 2023/03/08
Switzerland Bovine Spongiform Encephalopathy Atypical L-Type
Switzerland - Bovine spongiform encephalopathy - Immediate notification
BRAZIL BSE START DATE 2023/01/18
BRAZIL BSE CONFIRMATION DATE 2023/02/22
BRAZIL BSE END DATE 2023/03/03
SPAIN BSE START DATE 2023/01/21
SPAIN BSE CONFIRMATION DATE 2023/02/03
SPAIN BSE END DATE 2023/02/06
NETHERLANDS BSE START DATE 2023/02/01
NETHERLANDS BSE CONFIRMATION DATE 2023/02/01
NETHERLANDS BSE END DATE 2023/03/13
***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.***
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.
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.
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***thus questioning the origin of human sporadic cases***
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***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.
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PRION 2015 CONFERENCE
***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
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.
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.
SO, WHO'S UP FOR SOME MORE TSE PRION POKER, WHO'S ALL IN $$$
SO, ATYPICAL SCRAPIE ROUGHLY HAS 50 50 CHANCE ATYPICAL SCRAPIE IS CONTAGIOUS, AS NON-CONTAGIOUS, TAKE YOUR PICK, BUT I SAID IT LONG AGO WHEN USDA OIE ET AL MADE ATYPICAL SCRAPIE A LEGAL TRADING COMMODITY, I SAID YOUR PUTTING THE CART BEFORE THE HORSE, AND THAT'S EXACTLY WHAT THEY DID, and it's called in Texas, TEXAS TSE PRION HOLDEM POKER, WHO'S ALL IN $$$
***> AS is considered more likely (subjective probability range 50–66%) that AS is a non-contagious, rather than a contagious, disease.
SNIP...SEE;
THURSDAY, JULY 8, 2021
EFSA Scientific report on the analysis of the 2‐year compulsory intensified monitoring of atypical scrapie
SUNDAY, MARCH 19, 2023
Abandoned factory ‘undoubtedly’ contains dormant Mad Cow Disease that could threaten humans, Thruxted Mill, Queniborough CJD
DEFRA
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
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In the USA, under the Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law. Animals considered at high risk for CWD include:
1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and
2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.
Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.
The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES.
It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.
Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.
There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.
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36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011). The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE). Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison. snip..... The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).
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In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion. snip..... In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible... For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.
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Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.
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*** PLEASE SEE THIS URGENT UPDATE ON CWD AND FEED ANIMAL PROTEIN ***
Sunday, March 20, 2016
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed ***UPDATED MARCH 2016*** Singeltary Submission
PLoS One. 2020; 15(8): e0237410. Published online 2020 Aug 20. doi: 10.1371/journal.pone.0237410 PMCID: PMC7446902 PMID: 32817706
Very low oral exposure to prions of brain or saliva origin can transmit chronic wasting disease
Nathaniel D. Denkers, Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Validation, Visualization, Writing – review & editing,#1 Clare E. Hoover, Conceptualization, Data curation, Investigation, Writing – original draft, Writing – review & editing,#2 Kristen A. Davenport, Conceptualization, Data curation, Investigation, Writing – review & editing,3 Davin M. Henderson, Conceptualization, Data curation, Investigation, Methodology,1 Erin E. McNulty, Data curation, Investigation, Methodology, Writing – review & editing,1 Amy V. Nalls, Conceptualization, Investigation, Methodology, Writing – review & editing,1 Candace K. Mathiason, Conceptualization, Funding acquisition, Investigation, Supervision, Writing – review & editing,1 and Edward A. Hoover, Conceptualization, Data curation, Funding acquisition, Supervision, Writing – review & editing1,* Byron Caughey, Editor Author information Article notes Copyright and License information Disclaimer This article has been corrected.
See PLoS One. 2021 June 10; 16(6): e0253356. Associated Data Data Availability Statement
Abstract
The minimum infectious dose required to induce CWD infection in cervids remains unknown, as does whether peripherally shed prions and/or multiple low dose exposures are important factors in CWD transmission. With the goal of better understand CWD infection in nature, we studied oral exposures of deer to very low doses of CWD prions and also examined whether the frequency of exposure or prion source may influence infection and pathogenesis. We orally inoculated white-tailed deer with either single or multiple divided doses of prions of brain or saliva origin and monitored infection by serial longitudinal tissue biopsies spanning over two years. We report that oral exposure to as little as 300 nanograms (ng) of CWD-positive brain or to saliva containing seeding activity equivalent to 300 ng of CWD-positive brain, were sufficient to transmit CWD disease. This was true whether the inoculum was administered as a single bolus or divided as three weekly 100 ng exposures. However, when the 300 ng total dose was apportioned as 10, 30 ng doses delivered over 12 weeks, no infection occurred. While low-dose exposures to prions of brain or saliva origin prolonged the time from inoculation to first detection of infection, once infection was established, we observed no differences in disease pathogenesis. These studies suggest that the CWD minimum infectious dose approximates 100 to 300 ng CWD-positive brain (or saliva equivalent), and that CWD infection appears to conform more with a threshold than a cumulative dose dynamic.
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In conclusion, we have attempted to model and better understand CWD infection relative to natural exposure. The results demonstrate: (a) that the minimum CWD oral infectious dose is vastly lower than historical studies used to establish infection; (b) that a direct relationship exists between dose and incubation time to first prion replication detection in tonsils, irrespective of genotype; (c) that a difference was not discernible between brain vs. saliva source prions in ability to establish infection or in resultant disease course; and (d) that the CWD infection process appears to conform more to a threshold dose than an accumulative dose dynamic.
Bovine spongiform encephalopathy: the effect of oral exposure dose on attack rate and incubation period in cattle
G. A. H. Wells,1 T. Konold,1 M. E. Arnold,1 A. R. Austin,1 3 S. A. C. Hawkins,1 M. Stack,1 M. M. Simmons,1 Y. H. Lee,2 D. Gavier-Wide´n,3 M. Dawson1 4 and J. W. Wilesmith1 1 Correspondence G. A. H. Wells
g.a.h.wells@vla.defra.gsi.gov.uk
1 Veterinary Laboratories Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
2 National Veterinary Research and Quarantine Service, Anyang, Republic of Korea
3 National Veterinary Institute (SVA), SE-75189 Uppsala, Sweden
Received 27 July 2006
Accepted 18 November 2006
The dose–response of cattle exposed to the bovine spongiform encephalopathy (BSE) agent is an important component of modelling exposure risks for animals and humans and thereby, the modulation of surveillance and control strategies for BSE. In two experiments calves were dosed orally with a range of amounts of a pool of brainstems from BSE-affected cattle. Infectivity in the pool was determined by end-point titration in mice. Recipient cattle were monitored for clinical disease and, from the incidence of pathologically confirmed cases and their incubation periods (IPs), the attack rate and IP distribution according to dose were estimated. The dose at which 50 % of cattle would be clinically affected was estimated at 0.20 g brain material used in the experiment, with 95 % confidence intervals of 0.04–1.00 g. The IP was highly variable across all dose groups and followed a log-normal distribution, with decreasing mean as dose increased. There was no evidence of a threshold dose at which the probability of infection became vanishingly small, with 1/15 (7 %) of animals affected at the lowest dose (1 mg).
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DISCUSSION
The study has demonstrated that disease in cattle can be produced by oral exposure to as little as 1 mg brain homogenate (¡100.4 RIII mouse i.c./i.p. ID50 units) from clinically affected field cases of BSE and that the limiting dose for infection of calves is lower than this exposure...
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P04.27
Experimental BSE Infection of Non-human Primates: Efficacy of the Oral Route
Holznagel, E1; Yutzy, B1; Deslys, J-P2; Lasmzas, C2; Pocchiari, M3; Ingrosso, L3; Bierke, P4; Schulz-Schaeffer, W5; Motzkus, D6; Hunsmann, G6; Lwer, J1 1Paul-Ehrlich-Institut, Germany; 2Commissariat Energie Atomique, France; 3Instituto Superiore di Sanit, Italy; 4Swedish Institute for Infectious Disease control, Sweden; 5Georg August University, Germany; 6German Primate Center, Germany
Background:
In 2001, a study was initiated in primates to assess the risk for humans to contract BSE through contaminated food. For this purpose, BSE brain was titrated in cynomolgus monkeys.
Aims:
The primary objective is the determination of the minimal infectious dose (MID50) for oral exposure to BSE in a simian model, and, by in doing this, to assess the risk for humans. Secondly, we aimed at examining the course of the disease to identify possible biomarkers.
Methods:
Groups with six monkeys each were orally dosed with lowering amounts of BSE brain: 16g, 5g, 0.5g, 0.05g, and 0.005g. In a second titration study, animals were intracerebrally (i.c.) dosed (50, 5, 0.5, 0.05, and 0.005 mg).
Results:
In an ongoing study, a considerable number of high-dosed macaques already developed simian vCJD upon oral or intracerebral exposure or are at the onset of the clinical phase. However, there are differences in the clinical course between orally and intracerebrally infected animals that may influence the detection of biomarkers.
Conclusions:
Simian vCJD can be easily triggered in cynomolgus monkeys on the oral route using less than 5 g BSE brain homogenate. The difference in the incubation period between 5 g oral and 5 mg i.c. is only 1 year (5 years versus 4 years). However, there are rapid progressors among orally dosed monkeys that develop simian vCJD as fast as intracerebrally inoculated animals.
The work referenced was performed in partial fulfilment of the study 'BSE in primates' supported by the EU (QLK1-2002-01096).
1.3. Determination of the Minimal Infectious BSE Dose in Non-human Primates
In a concerted European effort involving 5 laboratories including ours, the BSE-macaque model was then used to evaluate the minimal amount of BSE-infected material necessary to induce vCJD in primates. Results so far show that 5g of infectious BSE cattle brain is sufficient to induce the disease in all recipient animals by the oral route, with 500 mg yielding an incomplete attack rate10,11). The ID50 of BSE cattle brain is 200 mg for cattle12). These results suggest a low species barrier between cattle and non-human primates.
look at the table and you'll see that as little as 1 mg (or 0.001 gm) caused 7% (1 of 14) of the cows to come down with BSE;
Risk of oral infection with bovine spongiform encephalopathy agent in primates
Corinne Ida Lasmzas, Emmanuel Comoy, Stephen Hawkins, Christian Herzog, Franck Mouthon, Timm Konold, Frdric Auvr, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Nicole Sals, Gerald Wells, Paul Brown, Jean-Philippe Deslys
Summary The uncertain extent of human exposure to bovine spongiform encephalopathy (BSE)--which can lead to variant Creutzfeldt-Jakob disease (vCJD)--is compounded by incomplete knowledge about the efficiency of oral infection and the magnitude of any bovine-to-human biological barrier to transmission. We therefore investigated oral transmission of BSE to non-human primates. We gave two macaques a 5 g oral dose of brain homogenate from a BSE-infected cow. One macaque developed vCJD-like neurological disease 60 months after exposure, whereas the other remained free of disease at 76 months. On the basis of these findings and data from other studies, we made a preliminary estimate of the food exposure risk for man, which provides additional assurance that existing public health measures can prevent transmission of BSE to man.
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BSE bovine brain inoculum
100 g 10 g 5 g 1 g 100 mg 10 mg 1 mg 01 mg 001 mg
Primate (oral route)* 1/2 (50%)
Cattle (oral route)* 10/10 (100%) 7/9 (78%) 7/10 (70%) 3/15 (20%) 1/15 (7%) 1/15 (7%)
RIII mice (ic ip route)* 17/18 (94%) 15/17 (88%) 1/14 (7%)
PrPres biochemical detection
The comparison is made on the basis of calibration of the bovine inoculum used in our study with primates against a bovine brain inoculum with a similar PrPres concentration that was
inoculated into mice and cattle.8 *Data are number of animals positive/number of animals surviving at the time of clinical onset of disease in the first positive animal (%). The accuracy of
bioassays is generally judged to be about plus or minus 1 log. ic ip=intracerebral and int****ritoneal.
Table 1: Comparison of transmission rates in primates and cattle infected orally with similar BSE brain inocula
Published online January 27, 2005
It is clear that the designing scientists must
also have shared Mr Bradley's surprise at the results because all the dose
levels right down to 1 gram triggered infection.
6. It also appears to me that Mr Bradley's answer (that it would take less than say 100 grams) was probably given with the benefit of hindsight; particularly if one considers that later in the same answer Mr Bradley expresses his surprise that it could take as little of 1 gram of brain to cause BSE by the oral route within the same species. This information did not become available until the "attack rate" experiment had been completed in 1995/96. This was a titration experiment designed to ascertain the infective dose. A range of dosages was used to ensure that the actual result was within both a lower and an upper limit within the study and the designing scientists would not have expected all the dose levels to trigger infection.
The dose ranges chosen by the most informed scientists at that time ranged from 1 gram to three times one hundred grams.
It is clear that the designing scientists must have also shared Mr Bradley's surprise at the results because all the dose levels right down to 1 gram triggered infection.
Notice of Request To Renew an Approved Information Collection: Specified Risk Materials DOCKET NUMBER Docket No. FSIS-2022-0027 Singeltary Submission
Greetings FSIS, USDA, et al,
Thank you kindly for allowing the public to comment on ;
(a) whether the proposed collection of information is necessary for the proper performance of FSIS’ functions, including whether the information will have practical utility;
(b) the accuracy of FSIS’ estimate of the burden of the proposed collection of information, including the validity of the method and assumptions used;
(c) ways to enhance the quality, utility, and clarity of the information to be collected; and
(d) ways to minimize the burden of the collection of information, including through the use of appropriate automated, electronic, mechanical, or other technological collection techniques, or other forms of information technology.
I will be commenting mostly on a, b, and c, because d, is wanting to minimize the burden of collection, and i do not think that is possible if ''These statutes mandate that FSIS protect the public by verifying that meat, poultry, and egg products are safe, wholesome, and properly labeled and packaged.'', is truly the intent of these statutes, and i would kindly like to explain why, and why it is so critical that these Specified Risk Materials SRM TSE Prion Statues are so important for public health, and WHY there is an urgent need to enhance them, considering the risk factors of Chronic Wasting Disease CWD TSE Prion in Cervid.
THIS collection of SRM materials information should be done all the time, year after year, and ending it EVER would be foolish, imo, not scientific, and will lead to future risk to public health, if you consider just how bad USDA/FSIS/APHIS/FDA failed so badly with the FDA PART 589 TSE PRION FEED BAN, the SRM REMOVAL, THE BSE SURVEILLANCE AND TESTING PROGRAMS, THEY FAILED ALL OF THEM TERRIBLY IMO, AND BY CONTINUING TO INSIST ON TESTING 25K CATTLE FOR BSE IS A DISASTER WATING TO HAPPEND IMO!
SPECIFIED RISK MATERS
Specified Risk Materials SRMs, are the most high risk infectious materials, organs, of a cow that is infected with Bovine Spongiform Encephalopathy, Transmissible Spongiform Encephalopathy, BSE TSE Prion. the atypical BSE strains are, like atypical L-type BSE are more infectious that the typical C-type BSE. Also, Science of the BSE TSE has evolved to show that there are more infectious tissues and organs than previously thought. I wish to kindly post all this evidence, as to show you why this information collection of SRMs are so vital to public safety, and why they should be enhanced for cattle, cervid, sheep, and goats, oh, and not to forget the new livestock prion disease in camel, the Camel Prion Disease CPD.
ONE other thing, you must remember, SCIENCE AND TRANSMISSION STUDIES have now shown that CWD and Scrapie can transmit to PIGS by Oral route. This should be included in any enhancement of the SRM or FDA PART 589 TSE PRION FEED ban.
NOT to forget Zoonosis of all of the above, i will post the latest science to date at the bottom of the attached files.
Thank You, terry
Singeltary further comments in attachment;
Specified Risk Materials DOCKET NUMBER Docket No. FSIS-2022-0027 Singeltary Submission Attachment https://downloads.regulations.gov/FSIS-2022-0027-0002/attachment_1.pdf Monday, December 5, 2022 Notice of Request To Renew an Approved Information Collection: Specified Risk Materials DOCKET NUMBER Docket No. FSIS-2022-0027 Singeltary Submission
SEE MAD COW FEED VIOLATIONS AFER MAD COW FEED VIOLATIONS ;
PUBLIC SUBMISSION
Use of Electronic Identification Eartags as Official Identification in Cattle and Bison APHIS-2021-0020-0001 Singeltary Submission
Comment from Singeltary Sr., Terry
Posted by the Animal and Plant Health Inspection Service on Mar 21, 2023
SEE ADDITIONAL COMMENTS IN ATTACHMENT;
Sunday, January 10, 2021
APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087] Singeltary Submission June 17, 2019
APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087] Singeltary Submission
Greetings APHIS et al,
I would kindly like to comment on APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087], and my comments are as follows, with the latest peer review and transmission studies as references of evidence.
THE OIE/USDA BSE Minimal Risk Region MRR is nothing more than free pass to import and export the Transmissible Spongiform Encephalopathy TSE Prion disease. December 2003, when the USDA et al lost it's supposedly 'GOLD CARD' ie BSE FREE STATUS (that was based on nothing more than not looking and not finding BSE), once the USA lost it's gold card BSE Free status, the USDA OIE et al worked hard and fast to change the BSE Geographical Risk Statuses i.e. the BSE GBR's, and replaced it with the BSE MRR policy, the legal tool to trade mad cow type disease TSE Prion Globally. The USA is doing just what the UK did, when they shipped mad cow disease around the world, except with the BSE MRR policy, it's now legal.
Also, the whole concept of the BSE MRR policy is based on a false pretense, that atypical BSE is not transmissible, and that only typical c-BSE is transmissible via feed. This notion that atypical BSE TSE Prion is an old age cow disease that is not infectious is absolutely false, there is NO science to show this, and on the contrary, we now know that atypical BSE will transmit by ORAL ROUTES, but even much more concerning now, recent science has shown that Chronic Wasting Disease CWD TSE Prion in deer and elk which is rampant with no stopping is sight in the USA, and Scrapie TSE Prion in sheep and goat, will transmit to PIGS by oral routes, this is our worst nightmare, showing even more risk factors for the USA FDA PART 589 TSE PRION FEED ban.
The FDA PART 589 TSE PRION FEED ban has failed terribly bad, and is still failing, since August 1997. there is tonnage and tonnage of banned potential mad cow feed that went into commerce, and still is, with one decade, 10 YEARS, post August 1997 FDA PART 589 TSE PRION FEED ban, 2007, with 10,000,000 POUNDS, with REASON, Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement. you can see all these feed ban warning letters and tonnage of mad cow feed in commerce, year after year, that is not accessible on the internet anymore like it use to be, you can see history of the FDA failure August 1997 FDA PART 589 TSE PRION FEED ban here, but remember this, we have a new outbreak of TSE Prion disease in a new livestock species, the camel, and this too is very worrisome.
WITH the OIE and the USDA et al weakening the global TSE prion surveillance, by not classifying the atypical Scrapie as TSE Prion disease, and the notion that they want to do the same thing with typical scrapie and atypical BSE, it's just not scientific.
WE MUST abolish the BSE MRR policy, go back to the BSE GBR risk assessments by country, and enhance them to include all strains of TSE Prion disease in all species. With Chronic Wasting CWD TSE Prion disease spreading in Europe, now including, Norway, Finland, Sweden, also in Korea, Canada and the USA, and the TSE Prion in Camels, the fact the the USA is feeding potentially CWD, Scrapie, BSE, typical and atypical, to other animals, and shipping both this feed and or live animals or even grains around the globe, potentially exposed or infected with the TSE Prion. this APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087], under it's present definition, does NOT show the true risk of the TSE Prion in any country. as i said, it's nothing more than a legal tool to trade the TSE Prion around the globe, nothing but ink on paper.
AS long as the BSE MRR policy stays in effect, TSE Prion disease will continued to be bought and sold as food for both humans and animals around the globe, and the future ramifications from friendly fire there from, i.e. iatrogenic exposure and transmission there from from all of the above, should not be underestimated. ...
APHIS Indemnity Regulations [Docket No. APHIS-2021-0010] RIN 0579-AE65 Singeltary Comment Submission
Comment from Singeltary Sr., Terry
Posted by the Animal and Plant Health Inspection Service on Sep 8, 2022
PDF]Freas, William TSS SUBMISSION File Format: PDF/Adobe Acrobat -
Page 1. J Freas, William From: Sent: To: Subject: Terry S. Singeltary
Sr. [flounder@wt.net] Monday, January 08,200l 3:03 PM freas ...
2. WE have a new Prion disease outbreak, in a new Livestock species, in Africa, and apparently, it's fairly large.
Monday, November 14, 2022
Prion Diseases in Dromedary Camels (CPD) 2022 Review
3. PIGS
Title: Prion infectivity detected in swine challenged with chronic wasting disease via the intracerebral or oral route
Author item MOORE, S - Orise Fellow item Kunkle, Robert item SMITH, JODI - Iowa State University item WEST-GREENLEE, M - Iowa State University item Greenlee, Justin Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 4/4/2016 Publication Date: N/A Citation: N/A
Interpretive Summary:
Technical Abstract: Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of North American cervids. The potential for swine to serve as a host for the agent of chronic wasting disease is unknown. In the US, feeding of ruminant by-products to ruminants is prohibited, but feeding of ruminant materials to swine, mink, and poultry still occurs. In addition, scavenging of CWD-affected cervid carcasses by feral pigs presents a potential risk for CWD exposure. The purpose of this study was to investigate the susceptibility of swine to the CWD agent following oral or intracranial experimental challenge. At 8 weeks of age, crossbred pigs were challenged by the intracranial route (n=20), oral route (n=19), or were left unchallenged (n=9). At approximately 6 months of age, the time at which commercial pigs reach market weight, half of the pigs in each group were culled (<6 month challenge groups). The remaining pigs (>6 month challenge groups) were allowed to incubate for up to 73 months post challenge (mpc). At death a complete necropsy examination was performed, including testing of tissues for misfolded prion protein (PrPcwd) by western blotting (WB), enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry (IHC). None of the pigs developed clinical signs consistent with prion disease. Four >6 month intracranially challenged pigs (survival times 45-73 mpc) were positive by ELISA, two were also positive by WB, and one was positive by IHC. One >6 month orally challenged pig (64 mpc) was positive by ELISA. To further investigate the potential for infectivity, brain tissue from selected pigs was bioassayed in mice expressing porcine PRNP. Tissue from the two WB-positive >6 month intracranially challenged pigs produced positive bioassay results, albeit with low attack rates and variable incubation periods. Interestingly, bioassay of material from the longest surviving >6 month orally challenged pig (72 mpc), which was negative for PrPcwd by all other tests, produced a positive bioassay result. Bioassay of material from additional animals is currently underway. This study demonstrates that pigs can serve as potential hosts for CWD, although with low attack rates and scant PrPcwd accumulation.
Detection of infectivity in orally challenged pigs using mouse bioassay raises the possibility that naturally exposed pigs act as a reservoir of CWD infectivity, even though affected pigs do not develop overt clinical signs or readily detectable PrPcwd.
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP
Author item MOORE, S - Orise Fellow item Kokemuller, Robyn item WEST-GREENLEE, M - Iowa State University item BALKEMA-BUSCHMANN, ANNE - Friedrich-Loeffler-institut item GROSCHUP, MARTIN - Friedrich-Loeffler-institut item Greenlee, Justin Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 5/10/2018 Publication Date: 5/22/2018 Citation: Moore, S.J., Kokemuller, R.D., West-Greenlee, M.H., Balkema-Buschmann, A., Groschup, M.H., Greenlee, J.J. 2018. The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP. Prion 2018, Santiago de Compostela, Spain, May 22-25, 2018. Paper No. WA15, page 44.
Interpretive Summary:
The successful transmission of pig-passaged CWD to Tg40 mice reported here suggests that passage of the CWD agent through pigs results in a change of the transmission characteristics which reduces the transmission barrier of Tg40 mice to the CWD agent. If this biological behavior is recapitulated in the original host species, passage of the CWD agent through pigs could potentially lead to increased pathogenicity of the CWD agent in humans.
''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.''
ARS researchers at Ames, Iowa conducted this experiment to test the susceptibility of swine to U.S. scrapie isolates by intracranial and oral inoculation. Necropsies were done on a subset of animals at approximately 6 months post inoculation (PI): the time the pigs were expected to reach market weight. Remaining pigs were maintained and monitored for clinical signs of transmissible spongiform encephalopathies (TSE) until study termination at 80 months PI or when removed due to intercurrent disease. Brain samples were examined by multiple diagnostic approaches, and for a subset of pigs in each inoculation group, bioassay in mice expressing porcine prion protein. At 6 months PI, no evidence of scrapie infection was noted by any diagnostic method. 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.
see full report;
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
2017 Annual Report
Objectives
Objective 1: Investigate the mechanisms of protein misfolding in prion disease, including the genetic determinants of misfolding of the prion protein and the environmental influences on protein misfolding as it relates to prion diseases. Subobjective 1.A: Investigate the differences in the unfolded state of wild-type and disease associated prion proteins to better understand the mechanism of misfolding in genetic prion disease. Subobjective 1.B: Investigate the influence of metal ions on the misfolding of the prion protein in vitro to determine if environmental exposure to metal ions may alter disease progression. Objective 2: Investigate the pathobiology of prion strains in natural hosts, including the influence of prion source genotype on interspecies transmission and the pathobiology of atypical transmissible spongiform encephalopathies (TSEs). Subobjective 2.A: Investigate the pathobiology of atypical TSEs. Subobjective 2.B: Investigate the influence of prion source genotype on interspecies transmission. Objective 3: Investigate sampling methodologies for antemortem detection of prion disease, including the utility of blood sampling as a means to assess prion disease status of affected animals and the utility of environmental sampling for monitoring herd prion disease status. Subobjective 3.A: Investigate the utility of blood sampling as a means to assess prion disease status of affected animals. Subobjective 3.B: Investigate the utility of environmental sampling for monitoring herd prion disease status.
Approach
The studies will focus on three animal transmissible spongiform encephalopathy (TSE) agents found in the United States: bovine spongiform encephalopathy (BSE); scrapie of sheep and goats; and chronic wasting disease (CWD) of deer, elk, and moose. The research will address sites of protein folding and misfolding as it relates to prion disease, accumulation of misfolded protein in the host, routes of infection, and ante mortem diagnostics with an emphasis on controlled conditions and natural routes of infection. Techniques used will include spectroscopic monitoring of protein folding/misfolding, clinical exams, histopathology, immunohistochemistry, and biochemical analysis of proteins. The enhanced knowledge gained from this work will help understand the underlying mechanisms of prion disease and mitigate the potential for unrecognized epidemic expansions of these diseases in populations of animals that could either directly or indirectly affect food animals.
Progress Report
All 8 project plan milestones for FY17 were fully met. Research efforts directed toward meeting objective 1 of our project plan center around the production of recombinant prion protein from either bacteria or mammalian tissue culture systems and collection of thermodynamic data on the folding of the recombinant prion protein produced. Both bacterial and mammalian expression systems have been established. Thermodynamic data addressing the denatured state of wild-type and a disease associated variant of bovine prion protein has been collected and a manuscript is in preparation. In research pertaining to objective 2, all studies have been initiated and animals are under observation for the development of clinical signs. The animal studies for this objective are long term and will continue until onset of clinical signs. In vitro studies planned in parallel to the animals studies have similarly been initiated and are ongoing. Objective 3 of the project plan focuses on the detection of disease associated prion protein in body fluids and feces collected from a time course study of chronic wasting disease inoculated animals. At this time samples are being collected as planned and methods for analysis are under development.
Accomplishments
1. Showed that swine are potential hosts for the scrapie agent. A naturally occurring prion disease has not been recognized in swine, but the agent of bovine spongiform encephalopathy does transmit to swine by experimental routes. Swine are thought to have a robust species barrier when exposed to the naturally occurring prion diseases of other species, but the susceptibility of swine to the agent of sheep scrapie has not been thoroughly tested. ARS researchers at Ames, Iowa conducted this experiment to test the susceptibility of swine to U.S. scrapie isolates by intracranial and oral inoculation. Necropsies were done on a subset of animals at approximately 6 months post inoculation (PI): the time the pigs were expected to reach market weight. Remaining pigs were maintained and monitored for clinical signs of transmissible spongiform encephalopathies (TSE) until study termination at 80 months PI or when removed due to intercurrent disease. Brain samples were examined by multiple diagnostic approaches, and for a subset of pigs in each inoculation group, bioassay in mice expressing porcine prion protein. At 6 months PI, no evidence of scrapie infection was noted by any diagnostic method. 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.
2. Determined that pigs naturally exposed to chronic wasting disease (CWD) may act as a reservoir of CWD infectivity. Chronic wasting disease is a naturally occurring, fatal, neurodegenerative disease of cervids. The potential for swine to serve as a host for the agent of CWD disease is unknown. The purpose of this study was to investigate the susceptibility of swine to the CWD agent following experimental oral or intracranial inoculation. Pigs were assigned to 1 of 3 groups: intracranially inoculated; orally inoculated; or non-inoculated. At market weight age, half of the pigs in each group were tested ('market weight' groups). The remaining pigs ('aged' groups) were allowed to incubate for up to 73 months post inoculation (MPI). Tissues collected at necropsy were examined for disease-associated prion protein (PrPSc) by multiple diagnostic methods. Brain samples from selected pigs were bioassayed in mice expressing porcine prion protein. Some pigs from each inoculated group were positive by one or more tests. Bioassay was positive in 4 out of 5 pigs assayed. Although only small amounts of PrPSc were detected using sensitive methods, this study demonstrates that pigs can serve as hosts for CWD. Detection of infectivity in orally inoculated pigs using mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity. Currently, swine rations in the U.S. could contain animal derived components including materials from deer or elk. In addition, feral swine could be exposed to infected carcasses in areas where CWD is present in wildlife populations. The current feed ban in the U.S. is based exclusively on keeping tissues from TSE infected cattle from entering animal feeds. These results indicating the susceptibility of pigs to CWD, 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.
3. Developed a method for amplification and discrimination of the 3 forms of BSE in cattle. The prion protein (PrP) is a protein that is the causative agent of transmissible spongiform encephalopathies (TSEs). The disease process involves conversion of the normal cellular PrP to a pathogenic misfolded conformation. This conversion process can be recreated in the lab using a misfolding amplification process known as real-time quaking induced conversion (RT-QuIC). RT-QuIC allows the detection of minute amounts of the abnormal infectious form of the prion protein by inducing misfolding in a supplied substrate. Although RT-QuIC has been successfully used to detect pathogenic PrP with substrates from a variety of host species, prior to this work bovine prion protein had not been proven for its practical uses for RT-QuIC. We demonstrated that prions from transmissible mink encephalopathy (TME) and BSE-infected cattle can be detected with using bovine prion proteins with RT-QuIC, and developed an RT-QuIC based approach to discriminate different forms of BSE. This rapid and robust method, both to detect and discriminate BSE types, is of importance as the economic implications for different types of BSE vary greatly.
Review Publications
snip...
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.
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.
CONFIDENTIAL
EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY
LINE TO TAKE
3. If questions on pharmaceuticals are raised at the Press conference, the suggested line to take is as follows:-
"There are no medicinal products licensed for use on the market which make use of UK-derived porcine tissues with which any hypothetical “high risk" ‘might be associated. The results of the recent experimental work at the CSM will be carefully examined by the CSM‘s Working Group on spongiform encephalopathy at its next meeting.
DO Hagger RM 1533 MT Ext 3201
While this clearly is a cause for concern we should not jump to the conclusion that this means that pigs will necessarily be infected by bone and meat meal fed by the oral route as is the case with cattle. ...
we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action.
May I, at the outset, reiterate that we should avoid dissemination of papers relating to this experimental finding to prevent premature release of the information. ...
3. It is particularly important that this information is not passed outside the Department, until Ministers have decided how they wish it to be handled. ...
But it would be easier for us if pharmaceuticals/devices are not directly mentioned at all. ...
Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom.....
4. RACCOONS, Beavers, Rodents, Mountain Lions, Pumas, Wolves
Chronic wasting disease detection in environmental and biological samples from a taxidermy site
Paulina Sotoa,b, J. Hunter Reedc, Mitch Lockwoodc, and Rodrigo Moralesa,b
aDepartment of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; bUniversidad Bernardo O’Higgins, Santiago, Chile; cTexas Parks and Wildlife Department, Texas, USA
Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy affecting captive and free-ranging cervids (e.g., mule deer, white-tailed deer, elk, reindeer, and moose). Nowadays, CWD is widely distributed in North America. It is suggested that CWD spreads due to direct animal contact or through exposure to contaminated environments previously inhabited by infected animals. CWD may also be spread through the movement of infected animals and carcasses. Taxidermy practices involve processing deer tissues (or whole animal carcasses). In many cases, the CWD status of processed animals is unknown. This can generate risks of disease spread and transmission. Taxidermy practices include different steps involving physical, chemical, and biological procedures. Without proper tissue handling or disposal practices, taxidermist facilities may become a focus of prion infectivity.
Aims: In this study, we evaluated the presence of infectious prions in a taxidermy facility believed to be exposed to CWD. Detection was performed using the Protein Misfolding Cyclic Amplification (PMCA) technique in biological and inert environmental samples.
Methods: We collected biological and environmental samples (plants, soils, insects, excreta, and others) from a taxidermy facility, and we tested these samples using the PMCA technique. In addition, we swabbed different surfaces possibly exposed to CWD-infected animals. For the PMCA reaction, we directly used a swab piece or 10 µL of 20% w/v homogenized samples.
Results: The PMCA analysis demonstrated CWD seeding activity in some of the components of this facility, including insects involved in head processing, soils, and a trash dumpster.
Conclusions: Different areas of this property were used for various taxidermy procedures. We were able to detect the presence of prions in i) soils that were in contact with the heads of dead animals, ii) insects involved in the cleaning of skulls, and iii) an empty dumpster where animal carcasses were previously placed. This is the first report demonstrating that swabbing is a helpful method to screen for prion infectivity on surfaces potentially contaminated with CWD. These findings are relevant as this swabbing and amplification strategy may be used to evaluate the disease status of other free-ranging and captive settings where there is a concern for CWD transmissions, such as at feeders and water troughs with CWD-exposed properties. This approach could have substantial implications for free-ranging cervid surveillance as well as in epidemiological investigations of CWD.
Funded by: USDA Grant number: AP20VSSPRS00C143 PRION 2022 ABSTRACTS, AND A BIG THANK YOU TO On behalf of the Prion2020/2022 Congress Organizing Committee and the NeuroPrion Association, we heartily invite you to join us for the International Conference Prion2020/2022 from 13.-16. September 2022 in Göttingen.
Prion 2022 Conference abstracts: pushing the boundaries
Volume 28, Number 4—April 2022
Research
Increased Attack Rates and Decreased Incubation Periods in Raccoons with Chronic Wasting Disease Passaged through Meadow Voles
S. Jo Moore, Christina M. Carlson, Jay R. Schneider, Christopher J. Johnson, and Justin J. GreenleeComments to Author Author affiliations: US Department of Agriculture, Ames, Iowa, USA (S.J. Moore, J.J. Greenlee); US Geological Survey National Wildlife Health Center, Madison, Wisconsin, USA (C.M. Carlson, J.R. Schneider, C.J. Johnson).
Abstract Chronic wasting disease (CWD) is a naturally-occurring neurodegenerative disease of cervids. Raccoons (Procyon lotor) and meadow voles (Microtus pennsylvanicus) have previously been shown to be susceptible to the CWD agent. To investigate the potential for transmission of the agent of CWD from white-tailed deer to voles and subsequently to raccoons, we intracranially inoculated raccoons with brain homogenate from a CWD-affected white-tailed deer (CWDWtd) or derivatives of this isolate after it had been passaged through voles 1 or 5 times. We found that passage of the CWDWtd isolate through voles led to a change in the biologic behavior of the CWD agent, including increased attack rates and decreased incubation periods in raccoons. A better understanding of the dynamics of cross-species transmission of CWD prions can provide insights into how these infectious proteins evolve in new hosts.
Transmissible spongiform encephalopathies, or prion diseases, are a group of fatal neurodegenerative diseases that include chronic wasting disease (CWD) in cervids, scrapie in sheep and goats, bovine spongiform encephalopathy (mad cow disease) in cattle, and Creutzfeldt-Jakob disease and Kuru in humans. As of January 2020, CWD has been reported in free-ranging and farmed cervids in 26 states in the United States and 3 provinces in Canada (1). CWD-affected cervids shed infectious prions into their environment during both the preclinical and clinical stages of disease (2–8), and infectivity persists in soil (9–13), on the surface of contaminated plant leaves and roots (14), and in association with mineral licks (15). Environmental contamination with CWD prions represents a source of infectious material to which noncervid wildlife species, including raccoons and other small mammals, can be exposed.
We previously reported the transmission of the agent of CWD from white-tailed deer (Odocoileus virginianus borealis) and elk to raccoons through experimental intracranial inoculation (16). Raccoons are able to propagate CWD prions from white-tailed deer and elk but with low attack rates (25%) and with disease-associated prion protein distribution restricted to the brain (16).
Overlap of raccoon and meadow vole distributions and chronic wasting disease epidemics, North America. A) Light purple shading indicates raccoon distribution; B) light teal shading indicates meadow vole distribution. Dark green areas and dark purple (A) and teal (B) overlays show known locations of chronic wasting disease in free-ranging cervids (as of March 2020). Figure 1. Overlap of raccoon and meadow vole distributions and chronic wasting disease epidemics, North America. A) Light purple shading indicates raccoon distribution; B) light teal shading indicates meadow vole distribution. Dark...
Successful transmission of the agent of CWD from white-tailed deer to 4 species of native North America rodents has been reported previously, and meadow voles (Microtus pennsylvanicus) were found to be the most susceptible species (17). Meadow voles are known to opportunistically scavenge carcasses and engage in cannibalistic behavior (18), providing a plausible route for exposure to CWD and the possibility of continued disease transmission. Small rodents are a food source for predators and scavengers, including raccoons, and meadow voles and raccoons inhabit overlapping geographic ranges that also overlap with locations undergoing cervid CWD epidemics (Figure 1). Therefore, the potential for direct exposure of meadow voles and raccoons to CWD infectivity in the environment exists. Indeed, studies in Wisconsin have shown that raccoons are present at deer carcasses and gut piles with a high frequency (19). In addition, because raccoons are mesopredators and scavengers, there is the potential for secondary exposure of raccoons through consumption of contaminated rodents.
To examine the potential for noncervid species to support CWD transmission, we intracranially inoculated raccoons with the agent of CWD from a white-tailed deer or with derivatives of the same inoculum after it had been passaged through meadow voles 1 or 5 times. In this study, we report the successful transmission of the agent of CWD from a white-tailed deer and vole-passaged CWD to raccoons through experimental intracranial inoculation. Our findings suggest passage of the CWD agent through voles results in a CWD agent with altered phenotypic properties.
snip...
Prion diseases of free-ranging animals do not exist in isolation. Meadow voles and raccoons are widespread in North America, and their habitat ranges overlap with those of CWD-affected white-tailed deer and other cervids. Therefore, a substantial potential for exposure of these or other off-target species to CWD infectivity in the environment exists. We have demonstrated that CWDWtd from a GS96 white-tailed deer transmitted readily to raccoons. Passage of this isolate through voles followed by intracranial inoculation of raccoons with vole-derived inoculum resulted in disease with different biologic characteristics and neuropathology than the original CWDWtd isolate. These results provide strong evidence for the emergence of a novel strain of CWD after passage in meadow voles and raccoons. Therefore, interspecies transmission of CWD prions between cervids and noncervid species that share the same habitat might represent a confounding factor in CWD-management programs. In addition, passage of CWD prions through off-target species might represent a source of novel CWD strains with unknown biologic characteristics, including zoonotic potential. Characterization of the biologic behavior of CWD isolates after cross-species transmission will help us develop more effective management strategies for CWD-affected populations.
Susceptibility of Beavers to Chronic Wasting Disease
Allen Herbst 1 2 3, Serene Wohlgemuth 2 4, Jing Yang 2 4, Andrew R Castle 2 4, Diana Martinez Moreno 2 5, Alicia Otero 6, Judd M Aiken 2 3, David Westaway 2 4, Debbie McKenzie 2 5
Affiliations expand
PMID: 35625395 PMCID: PMC9137852 DOI: 10.3390/biology11050667
Abstract
Chronic wasting disease (CWD) is a contagious, fatal, neurodegenerative prion disease of cervids. The expanding geographical range and rising prevalence of CWD are increasing the risk of pathogen transfer and spillover of CWD to non-cervid sympatric species. As beavers have close contact with environmental and food sources of CWD infectivity, we hypothesized that they may be susceptible to CWD prions. We evaluated the susceptibility of beavers to prion diseases by challenging transgenic mice expressing beaver prion protein (tgBeaver) with five strains of CWD, four isolates of rodent-adapted prions and one strain of Creutzfeldt-Jakob disease. All CWD strains transmitted to the tgBeaver mice, with attack rates highest from moose CWD and the 116AG and H95+ strains of deer CWD. Mouse-, rat-, and especially hamster-adapted prions were also transmitted with complete attack rates and short incubation periods. We conclude that the beaver prion protein is an excellent substrate for sustaining prion replication and that beavers are at risk for CWD pathogen transfer and spillover.
Keywords: beavers; chronic wasting disease; prions; wildlife diseases.
FRIDAY, MARCH 24, 2023
Mountain lions, Wolves, Coyotes, could help stop the spread of CWD TSE Prion in deer, WHERE STUPID MEETS THE ROAD!
5. RODENTS
Chronic Wasting Disease (CWD) Susceptibility of Several North American Rodents That Are Sympatric with Cervid CWD Epidemics
Authors: Dennis M. Heisey dheisey@usgs.gov, Natalie A. Mickelsen, Jay R. Schneider, Christopher J. Johnson, Chad J. Johnson, Julia A. Langenberg, Philip N. Bochsler, Delwyn P. Keane, Daniel J. BarrAUTHORS INFO & AFFILIATIONS
DOI: https://doi.org/10.1128/JVI.00560-09
ABSTRACT
Chronic wasting disease (CWD) is a highly contagious always fatal neurodegenerative disease that is currently known to naturally infect only species of the deer family, Cervidae. CWD epidemics are occurring in free-ranging cervids at several locations in North America, and other wildlife species are certainly being exposed to infectious material. To assess the potential for transmission, we intracerebrally inoculated four species of epidemic-sympatric rodents with CWD. Transmission was efficient in all species; the onset of disease was faster in the two vole species than the two Peromyscus spp. The results for inocula prepared from CWD-positive deer with or without CWD-resistant genotypes were similar. Survival times were substantially shortened upon second passage, demonstrating adaptation. Unlike all other known prion protein sequences for cricetid rodents that possess asparagine at position 170, our red-backed voles expressed serine and refute previous suggestions that a serine in this position substantially reduces susceptibility to CWD. Given the scavenging habits of these rodent species, the apparent persistence of CWD prions in the environment, and the inevitable exposure of these rodents to CWD prions, our intracerebral challenge results indicate that further investigation of the possibility of natural transmission is warranted.
snip...
In light of our findings, the possibility of natural transmission to rodents cannot be dismissed. This is concerning because of a TSE's ability to change its properties and host affinities after being passaged (4). Cannibalism and scavenging are common among small rodents, and small rodents are a very important food source for many predators and scavengers. Small rodent tissue also enters the domestic livestock and human food chain by accidental inclusion in grain and forage. Further investigation of these species as potential hosts, bridge species, and reservoirs of CWD is warranted. Even in its natural cervid hosts, the mechanisms of natural transmission and infection of CWD are not well understood. However, the ability to support amplification of PrPd would seem to be a prerequisite, which all of our rodent species have demonstrated. We have initiated studies to examine the susceptibility of these rodent species via more natural routes of infection.
6. INSECTS
mSphere . 2021 Aug 25;6(4):e0051521. doi: 10.1128/mSphere.00515-21. Epub 2021 Aug 4.
Evaluation of Winter Ticks (Dermacentor albipictus) Collected from North American Elk (Cervus canadensis) in an Area of Chronic Wasting Disease Endemicity for Evidence of PrPCWD Amplification Using Real-Time Quaking-Induced Conversion
Assay N J Haley 1, D M Henderson 2, K Senior 1, M Miller 1, R Donner 1 Affiliations expand PMID: 34346708 PMCID: PMC8386475 DOI: 10.1128/mSphere.00515-21 Free PMC article
Abstract Chronic wasting disease (CWD) is a progressive and fatal spongiform encephalopathy of deer and elk species, caused by a misfolded variant of the normal prion protein. Horizontal transmission of the misfolded CWD prion between animals is thought to occur through shedding in saliva and other forms of excreta. The role of blood in CWD transmission is less clear, though infectivity has been demonstrated in various blood fractions. Blood-feeding insects, including ticks, are known vectors for a range of bacterial and viral infections in animals and humans, though to date, there has been no evidence for their involvement in prion disease transmission. In the present study, we evaluated winter ticks (Dermacentor albipictus) collected from 136 North American elk (Cervus canadensis) in an area where CWD is endemic for evidence of CWD prion amplification using the real-time quaking-induced conversion assay (RT-QuIC). Although 30 elk were found to be CWD positive (22%) postmortem, amplifiable prions were found in just a single tick collected from an elk in advanced stages of CWD infection, with some evidence for prions in ticks collected from elk in mid-stage infection. These findings suggest that further investigation of ticks as reservoirs for prion disease may be warranted. IMPORTANCE This study reports the first finding of detectable levels of prions linked to chronic wasting disease in a tick collected from a clinically infected elk. Using the real-time quaking-induced conversion assay (RT-QuIC), "suspect" samples were also identified; these suspect ticks were more likely to have been collected from CWD-positive elk, though suspect amplification was also observed in ticks collected from CWD-negative elk. Observed levels were at the lower end of our detection limits, though our findings suggest that additional research evaluating ticks collected from animals in late-stage disease may be warranted to further evaluate the role of ticks as potential vectors of chronic wasting disease.
Keywords: RT-QuIC; chronic wasting disease; elk; prion; tick; tick-borne pathogens.
SATURDAY, DECEMBER 21, 2013
Parelaphostrongylus (Brainworm) Infection in Deer and Elk and the potential for CWD TSE prion consumption and spreading there from ?
I brought up a concern for a worm long ago, that gets in the brains of cervids, and then the worm gets excreted via feces, and then deer forage and eat that worm. if the host cervid of this worm has CWD, could this later transmit CWD?
I was concerned about this long ago, still am. I was curious what any else might think about this potential mode of transmission with cwd ?
7. MILK
Emerg Infect Dis. 2011 May; 17(5): 848–854.
doi: 10.3201/eid1705.101654
PMCID: PMC3321785
PMID: 21529394
Experimental Oral Transmission of Atypical Scrapie to Sheep
Marion M. Simmons,
corresponding author S. Jo Moore,1 Timm Konold, Lisa Thurston, Linda A. Terry, Leigh Thorne, Richard Lockey, Chris Vickery, Stephen A.C. Hawkins, Melanie J. Chaplin, and John Spiropoulos
Abstract
To investigate the possibility of oral transmission of atypical scrapie in sheep and determine the distribution of infectivity in the animals’ peripheral tissues, we challenged neonatal lambs orally with atypical scrapie; they were then killed at 12 or 24 months. Screening test results were negative for disease-specific prion protein in all but 2 recipients; they had positive results for examination of brain, but negative for peripheral tissues. Infectivity of brain, distal ileum, and spleen from all animals was assessed in mouse bioassays; positive results were obtained from tissues that had negative results on screening. These findings demonstrate that atypical scrapie can be transmitted orally and indicate that it has the potential for natural transmission and iatrogenic spread through animal feed. Detection of infectivity in tissues negative by current surveillance methods indicates that diagnostic sensitivity is suboptimal for atypical scrapie, and potentially infectious material may be able to pass into the human food chain.
GOAT MILK
BMC Vet Res . 2017 May 4;13(1):122. doi: 10.1186/s12917-017-1036-1.
Codon 141 polymorphisms of the ovine prion protein gene affect the phenotype of classical scrapie transmitted from goats to sheep
Timm Konold 1, Laura J Phelan 2, Ben R Donnachie 3, Melanie J Chaplin 3, Saira Cawthraw 4, Lorenzo González 5
PMID: 28472956 PMCID: PMC5418773 DOI: 10.1186/s12917-017-1036-1
Abstract
Background: A study to investigate transmission of classical scrapie via goat milk was carried out in sheep: firstly, lambs were challenged orally with goat scrapie brain homogenate to confirm transmission of scrapie from goats to sheep. In the second study phase, milk from scrapie-infected goats was fed to lambs. Lambs were selected according to their prion protein gene (PRNP) genotype, which was either VRQ/VRQ or ARQ/ARQ, with or without additional polymorphisms at codon 141 (FF141, LF141 or LL141) of the ovine PRNP. This report describes the clinical, pathological and molecular phenotype of goat scrapie in those sheep that progressed to clinical end-stage.
Results: Ten sheep (six VRQ/VRQ and four ARQ/ARQ, of which three FF141 and one LL141) challenged with one of two scrapie brain homogenates, and six pairs of sheep (ARQ, of which five LL141 and seven LF141) fed milk from six different goats, developed clinical disease, which was characterised by a pruritic (all VRQ/VRQ and LL141 sheep) or a non-pruritic form (all LF141 and FF141 sheep). Immunohistochemical (IHC) examination revealed that the pattern of intra- and extracellular accumulation of disease-associated prion protein in the brain was also dependent on PRNP polymorphisms at codon 141, which was similar in VRQ and LL141 sheep but different from LF141 and FF141 sheep. The influence of codon 141 was also seen in discriminatory Western blot (WB), with LF141 and FF141 sheep showing a bovine spongiform encephalopathy-like profile (diminished reactivity with P4 antibody) on brain tissue. However, discriminatory WB in lymphoid tissues, and IHC pattern and profile both in lymphoid and brain tissue was consistent with classical scrapie in all sheep.
Conclusions: This study provided further evidence that the clinical presentation and the pathological and molecular phenotypes of scrapie in sheep are influenced by PRNP polymorphisms, particularly at codon 141. Differences in the truncation of disease-associated prion protein between LL141 sheep and those carrying the F141 allele may be responsible for these observations.
Keywords: Clinical picture; Codon 141; Goat; Immunohistochemistry; PRNP genotype; Prion protein; Scrapie; Sheep; Transmission; Western immunoblot.
8. 21 CFR Part 589.2000 Failed Mad Cow Feed Ban in USA (these are just a few examples of 100s i have filed...terry)
BANNED MAD COW FEED IN COMMERCE IN ALABAMA
Date: September 6, 2006 at 7:58 am PST PRODUCT
a) EVSRC Custom dairy feed, Recall # V-130-6;
b) Performance Chick Starter, Recall # V-131-6;
c) Performance Quail Grower, Recall # V-132-6;
d) Performance Pheasant Finisher, Recall # V-133-6.
CODE None RECALLING FIRM/MANUFACTURER Donaldson & Hasenbein/dba J&R Feed Service, Inc., Cullman, AL, by telephone on June 23, 2006 and by letter dated July 19, 2006. Firm initiated recall is complete.
REASON
Dairy and poultry feeds were possibly contaminated with ruminant based protein.
VOLUME OF PRODUCT IN COMMERCE 477.72 tons
DISTRIBUTION AL
______________________________
http://www.fda.gov/bbs/topics/enforce/2006/ENF00968.html
PRODUCT Bulk custom dairy pre-mixes,
Recall # V-120-6 CODE None RECALLING FIRM/MANUFACTURER Ware Milling Inc., Houston, MS, by telephone on June 23, 2006. Firm initiated recall is complete. REASON Possible contamination of dairy animal feeds with ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 350 tons
DISTRIBUTION AL and MS
______________________________
PRODUCT
a) Tucker Milling, LLC Tm 32% Sinking Fish Grower, #2680-Pellet, 50 lb. bags, Recall # V-121-6;
b) Tucker Milling, LLC #31120, Game Bird Breeder Pellet, 50 lb. bags, Recall # V-122-6;
c) Tucker Milling, LLC #31232 Game Bird Grower, 50 lb. bags, Recall # V-123-6;
d) Tucker Milling, LLC 31227-Crumble, Game Bird Starter, BMD Medicated, 50 lb bags, Recall # V-124-6;
e) Tucker Milling, LLC #31120, Game Bird Breeder, 50 lb bags, Recall # V-125-6;
f) Tucker Milling, LLC #30230, 30 % Turkey Starter, 50 lb bags, Recall # V-126-6;
g) Tucker Milling, LLC #30116, TM Broiler Finisher, 50 lb bags, Recall # V-127-6
CODE All products manufactured from 02/01/2005 until 06/20/2006 RECALLING FIRM/MANUFACTURER Recalling Firm: Tucker Milling LLC, Guntersville, AL, by telephone and visit on June 20, 2006, and by letter on June 23, 2006. Manufacturer: H. J. Baker and Brothers Inc., Stamford, CT. Firm initiated recall is ongoing.
REASON Poultry and fish feeds which were possibly contaminated with ruminant based protein were not labeled as "Do not feed to ruminants".
VOLUME OF PRODUCT IN COMMERCE 7,541-50 lb bags
DISTRIBUTION AL, GA, MS, and TN
END OF ENFORCEMENT REPORT FOR AUGUST 9, 2006
###
http://www.fda.gov/bbs/topics/ENFORCE/2006/ENF00964.html
Subject: MAD COW FEED RECALL AL AND FL VOLUME OF PRODUCT IN COMMERCE 125 TONS Products manufactured from 02/01/2005 until 06/06/2006
Date: August 6, 2006 at 6:16 pm PST PRODUCT
a) CO-OP 32% Sinking Catfish, Recall # V-100-6;
b) Performance Sheep Pell W/Decox/A/N, medicated, net wt. 50 lbs, Recall # V-101-6;
c) Pro 40% Swine Conc Meal -- 50 lb, Recall # V-102-6;
d) CO-OP 32% Sinking Catfish Food Medicated, Recall # V-103-6;
e) "Big Jim's" BBB Deer Ration, Big Buck Blend, Recall # V-104-6;
f) CO-OP 40% Hog Supplement Medicated Pelleted, Tylosin 100 grams/ton, 50 lb. bag, Recall # V-105-6;
g) Pig Starter Pell II, 18% W/MCDX Medicated 282020, Carbadox -- 0.0055%, Recall # V-106-6;
h) CO-OP STARTER-GROWER CRUMBLES, Complete Feed for Chickens from Hatch to 20 Weeks, Medicated, Bacitracin Methylene Disalicylate, 25 and 50 Lbs, Recall # V-107-6;
i) CO-OP LAYING PELLETS, Complete Feed for Laying Chickens, Recall # 108-6;
j) CO-OP LAYING CRUMBLES, Recall # V-109-6;
k) CO-OP QUAIL FLIGHT CONDITIONER MEDICATED, net wt 50 Lbs, Recall # V-110-6;
l) CO-OP QUAIL STARTER MEDICATED, Net Wt. 50 Lbs, Recall # V-111-6;
m) CO-OP QUAIL GROWER MEDICATED, 50 Lbs, Recall # V-112-6 CODE
Product manufactured from 02/01/2005 until 06/06/2006
RECALLING FIRM/MANUFACTURER Alabama Farmers Cooperative, Inc., Decatur, AL, by telephone, fax, email and visit on June 9, 2006. FDA initiated recall is complete.
REASON Animal and fish feeds which were possibly contaminated with ruminant based protein not labeled as "Do not feed to ruminants".
VOLUME OF PRODUCT IN COMMERCE 125 tons
DISTRIBUTION AL and FL
END OF ENFORCEMENT REPORT FOR AUGUST 2, 2006
###
http://www.fda.gov/bbs/topics/enforce/2006/ENF00963.html
MAD COW FEED RECALL USA EQUALS 10,878.06 TONS NATIONWIDE Sun Jul 16, 2006 09:22 71.248.128.67
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINE -- CLASS II
______________________________
PRODUCT
a) PRO-LAK, bulk weight, Protein Concentrate for Lactating Dairy Animals, Recall # V-079-6;
b) ProAmino II, FOR PREFRESH AND LACTATING COWS, net weight 50lb (22.6 kg), Recall # V-080-6;
c) PRO-PAK, MARINE & ANIMAL PROTEIN CONCENTRATE FOR USE IN ANIMAL FEED, Recall # V-081-6;
d) Feather Meal, Recall # V-082-6 CODE
a) Bulk
b) None
c) Bulk
d) Bulk
RECALLING FIRM/MANUFACTURER H. J. Baker & Bro., Inc., Albertville, AL, by telephone on June 15, 2006 and by press release on June 16, 2006. Firm initiated recall is ongoing.
REASON
Possible contamination of animal feeds with ruminent derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 10,878.06 tons
DISTRIBUTION Nationwide
END OF ENFORCEMENT REPORT FOR July 12, 2006
###
http://www.fda.gov/bbs/topics/enforce/2006/ENF00960.html
10,000,000+ LBS. of PROHIBITED BANNED MAD COW FEED I.E. BLOOD LACED MBM IN COMMERCE USA 2007
Date: March 21, 2007 at 2:27 pm PST
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINES -- CLASS II
___________________________________
PRODUCT
Bulk cattle feed made with recalled Darling's 85% Blood Meal, Flash Dried, Recall # V-024-2007
CODE
Cattle feed delivered between 01/12/2007 and 01/26/2007
RECALLING FIRM/MANUFACTURER
Pfeiffer, Arno, Inc, Greenbush, WI. by conversation on February 5, 2007.
Firm initiated recall is ongoing.
REASON
Blood meal used to make cattle feed was recalled because it was cross- contaminated with prohibited bovine meat and bone meal that had been manufactured on common equipment and labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE
42,090 lbs.
DISTRIBUTION
WI
___________________________________
PRODUCT
Custom dairy premix products: MNM ALL PURPOSE Pellet, HILLSIDE/CDL Prot- Buffer Meal, LEE, M.-CLOSE UP PX Pellet, HIGH DESERT/ GHC LACT Meal, TATARKA, M CUST PROT Meal, SUNRIDGE/CDL PROTEIN Blend, LOURENZO, K PVM DAIRY Meal, DOUBLE B DAIRY/GHC LAC Mineral, WEST PIONT/GHC CLOSEUP Mineral, WEST POINT/GHC LACT Meal, JENKS, J/COMPASS PROTEIN Meal, COPPINI - 8# SPECIAL DAIRY Mix, GULICK, L-LACT Meal (Bulk), TRIPLE J - PROTEIN/LACTATION, ROCK CREEK/GHC MILK Mineral, BETTENCOURT/GHC S.SIDE MK-MN, BETTENCOURT #1/GHC MILK MINR, V&C DAIRY/GHC LACT Meal, VEENSTRA, F/GHC LACT Meal, SMUTNY, A- BYPASS ML W/SMARTA, Recall # V-025-2007
CODE
The firm does not utilize a code - only shipping documentation with commodity and weights identified.
RECALLING FIRM/MANUFACTURER
Rangen, Inc, Buhl, ID, by letters on February 13 and 14, 2007. Firm initiated recall is complete.
REASON
Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE
9,997,976 lbs.
DISTRIBUTION
ID and NV
END OF ENFORCEMENT REPORT FOR MARCH 21, 2007
http://www.fda.gov/Safety/Recalls/EnforcementReports/2007/ucm120446.htm
Control of Chronic Wasting Disease OMB Control Number: 0579-0189 APHIS-2021-0004 Singeltary Submission
Docket No. APHIS-2018-0011 Chronic Wasting Disease Herd Certification
SUNDAY, OCTOBER 30, 2022
Why is USDA "only" testing 25,000 samples a year?
WEDNESDAY, NOVEMBER 30, 2022
USDA Bovine Spongiform Encephalopathy BSE, Scrapie, CWD, Testing and Surveillance 2022 A Review of History
Terry S. Singeltary Sr.
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