Switzerland OIE Bovine spongiform encephalopathy atypical BSE type L TSE Prion
OIE Bovine spongiform encephalopathy, Switzerland
Information received on 05/02/2020 from Mr Hans Wyss, Chief Veterinary Officer, Schwarzenburgstrasse 161, Swiss Federal Veterinary Office, LIEBEFELD BERNE, Switzerland
Summary
Report type Immediate notification (Final report)
Date of start of the event 29/01/2020
Date of confirmation of the event 03/02/2020
Report date 05/02/2020
Date submitted to OIE 05/02/2020
Date event resolved 03/02/2020
Reason for notification Recurrence of a listed disease
Date of previous occurrence 03/2012
Manifestation of disease Clinical disease
Causal agent Prion (atypical BSE type L)
Nature of diagnosis Laboratory (advanced)
This event pertains to the whole country
New outbreaks (1)
Outbreak 1 Einsiedeln, Schwyz
Date of start of the outbreak 29/01/2020
Outbreak status Resolved (03/02/2020)
Epidemiological unit Farm
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Cattle 68 1 0 0 1
Summary of outbreaks Total outbreaks: 1
Total animals affected
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Cattle 68 1 0 0 1
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Cattle 1.47% 0.00% 0.00% 1.47%
*Removed from the susceptible population through death, destruction and/or slaughter
Epidemiology
Source of the outbreak(s) or origin of infection
Unknown or inconclusive
Epidemiological comments
Confirmation of atypical Bovine spongiform encephalopathy (BSE) in a cow on 3 February 2020. The 13 year old cow from a holding in the Canton of Schwyz was subject to emergency-slaughter on 23 January 2020. Samples of the brain stem were sent in for analysis and confirmed at the Swiss National Reference Laboratory for Transmissible Spongiform Encephalopathies. The sample tested positive in the rapid test for BSE "Priostrip BSE" and was confirmed by Western lmmunoblot. The pathological prion protein could be classified as (L) -Type BSE and therefore as an atypical case of BSE. The entire carcass was disposed of as category 1 material.
Control measures
Measures applied
Vaccination prohibited
No treatment of affected animals
Measures to be applied
No other measures
Diagnostic test results
Laboratory name and type Species Test Test date Result
National Reference Laboratory (National laboratory) Cattle western blot 03/02/2020 Positive
Future Reporting
The event is resolved. No more reports will be submitted.
Map of outbreak locations
FRIDAY, MARCH 16, 2012
atypical BSE Mad cow disease found in Switzerland March 12, 2012
Lancet. 2002 Jul 13;360(9327):139-41.
Incidence of Creutzfeldt-Jakob disease in Switzerland.
Glatzel M1, Rogivue C, Ghani A, Streffer JR, Amsler L, Aguzzi A.
Author information
Abstract
The incidence of Creutzfeldt-Jakob disease (CJD) in Switzerland increased two-fold in 2001, and figures from the first quarter of 2002 indicate that it continues to rise. Neither age at onset nor duration of disease were different from previous years. Genetic analysis of the 27 reported cases revealed only one disease-associated mutation in the prion gene. None of the recognised risk factors for acquired CJD were reported on the official notification forms. Glycotype profiling, histopathology, and immunohistochemistry indicate that none of the cases fulfilled the definition of variant CJD, which is thought to be caused by bovine prions. Several scenarios could account for the increase in CJD, including improved reporting, iatrogenic transmission, and transmission of a prion zoonosis.
PMID: 12126826 DOI: 10.1016/S0140-6736(02)09384-4
Heightened incidence of sporadic Creutzfeldt-Jakob disease is associated with a shift in clinicopathological profiles
Stoeck, K; Hess, K; Amsler, L; Eckert, T; Zimmermann, D R; Aguzzi, A; Glatzel, M (2008). Heightened incidence of sporadic Creutzfeldt-Jakob disease is associated with a shift in clinicopathological profiles. Journal of Neurology, 255(10):1464-1472.
Abstract
Incidences of human transmissible spongiform encephalopathies are monitored by national registries in the majority of countries in Western Europe. During the past 13 years incidences for Creutzfeldt-Jakob disease (CJD) in Switzerland fluctuated between 0.4 and 2.63 cases/10(6) inhabitants. We have compared clinicpathological patient profiles including geographic and gender distribution, age at disease onset, duration of disease, clinical symptoms, and recognized or hypothetical risk factors for CJD, genetic risk factors, biochemical and histopathological data for two cohorts of Swiss sporadic CJD patients from years of regular sporadic CJD incidence (1996-2000, mean incidence 1.3 cases/10(6) inhabitants, n = 47) to Swiss sporadic CJD patients from years of elevated sporadic CJD incidence (2001-2004, mean incidence 2.3 cases/10(6) inhabitants, n = 73). Sporadic CJD patients from the cohort with elevated sporadic CJD incidence presented with a higher frequency of rare sporadic CJD subtypes. Patients of these subtypes were significantly older and showed a skewed male/female ratio when compared to published patients of identical sporadic CJD-types or to patients from the 1996-2000 cohort and indicates that improved detection of rare sporadic CJD subtypes may have contributed to increased incidence.
Iatrogenic and sporadic Creutzfeldt-Jakob disease in 2 sisters without mutation in the prion protein gene
Frontzek, Karl; Moos, Rita; Schaper, Elke; Jann, Lukas; Herfs, Gregor; Zimmermann, Dieter R; Aguzzi, Adriano; Budka, Herbert (2015). Iatrogenic and sporadic Creutzfeldt-Jakob disease in 2 sisters without mutation in the prion protein gene. Prion, 9(6):444-448.
Abstract
Human genetic prion diseases have invariably been linked to alterations of the prion protein (PrP) gene PRNP. Two sisters died from probable Creutzfeldt-Jakob disease (CJD) in Switzerland within 14 y. At autopsy, both patients had typical spongiform change in their brains accompanied by punctuate deposits of PrP. Biochemical analyses demonstrated proteinase K-resistant PrP. Sequencing of PRNP showed 2 wild-type alleles in both siblings. Retrospectively, clinical data revealed a history of dural transplantation in the initially deceased sister, compatible with a diagnosis of iatrogenic CJD. Clinical and familial histories provided no evidence for potential horizontal transmission. This observation of 2 siblings suffering from CJD without mutations in the PRNP gene suggests potential involvement of non-PRNP genes in prion disease etiology.
Monday, February 3, 2020
Informing Patient Contacts About Iatrogenic Creutzfeldt Jakob Disease
THURSDAY, DECEMBER 12, 2019
Heidenhain Variant Creutzfeldt Jakob Disease hvCJD, sporadic spontaneous CJD and the TSE Prion December 14, 2019
SUNDAY, DECEMBER 29, 2019
Variant CJD 18 years of research and surveillance
WEDNESDAY, DECEMBER 04, 2019
Three Cases of Creutzfeldt-Jakob Disease with Visual Disturbances as Initial Manifestation
Friday, September 27, 2019
Prion disease and recommended procedures for flexible endoscope reprocessing – a review of policies worldwide and proposal for a simplified approach
THURSDAY, SEPTEMBER 26, 2019
Veterinary Biologics Guideline 3.32E: Guideline for minimising the risk of introducing transmissible spongiform encephalopathy prions and other infectious agents through veterinary biologics
SATURDAY, SEPTEMBER 21, 2019
National Variability in Prion Disease–Related Safety Policies for Neurologic Procedures
Wednesday, September 11, 2019
Is the re-use of sterilized implant abutments safe enough? (Implant abutment safety) iatrogenic TSE Prion
FRIDAY, SEPTEMBER 06, 2019
Disinfection of Multi-Use Ocular Equipment for Ophthalmological Procedures: A Review of Clinical Effectiveness, Cost-Effectiveness, and Guidelines
MONDAY, AUGUST 26, 2019
Creutzfeldt Jakob Disease CJD, TSE, Prion, Surveillance Update August 2019
SUNDAY, MARCH 10, 2019
National Prion Disease Pathology Surveillance Center Cases Examined¹ Updated Feb 1, 2019 Variably protease-sensitive prionopathy VPSPr
***> In conclusion, sensory symptoms and loss of reflexes in Gerstmann-Sträussler-Scheinker syndrome can be explained by neuropathological changes in the spinal cord. We conclude that the sensory symptoms and loss of lower limb reflexes in Gerstmann-Sträussler-Scheinker syndrome is due to pathology in the caudal spinal cord. <***
***> The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology.<***
***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD. <***
***> All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals.<***
***> In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids.'' Scientific opinion on chronic wasting disease (II) <***
RESEARCH ARTICLE
Enhanced detection of prion infectivity from blood by preanalytical enrichment with peptoid-conjugated beads
Simone HornemannID1 *, Petra Schwarz1 , Elisabeth J. Rushing1 , Michael D. Connolly3 , Ronald N. Zuckermann3 , Alice Y. Yam2¤ , Adriano AguzziID1 * 1 Institute of Neuropathology, University of Zurich, Zurich, Switzerland, 2 Novartis Vaccines and Diagnostics Inc., Emeryville, California, United States of America, 3 Biological Nanostructures Facility, The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America ¤ Current address: Sutro Biopharma, San Francisco, California, United States of America * Adriano.Aguzzi@usz.ch (AA); Simone.Hornemann@usz.ch (SH)
Abstract
Prions cause transmissible infectious diseases in humans and animals and have been found to be transmissible by blood transfusion even in the presymptomatic stage. However, the concentration of prions in body fluids such as blood and urine is extremely low; therefore, direct diagnostic tests on such specimens often yield false-negative results. Quantitative preanalytical prion enrichment may significantly improve the sensitivity of prion assays by concentrating trace amounts of prions from large volumes of body fluids. Here, we show that beads conjugated to positively charged peptoids not only captured PrP aggregates from plasma of prion-infected hamsters, but also adsorbed prion infectivity in both the symptomatic and preclinical stages of the disease. Bead absorbed prion infectivity efficiently transmitted disease to transgenic indicator mice. We found that the readout of the peptoidbased misfolded protein assay (MPA) correlates closely with prion infectivity in vivo, thereby validating the MPA as a simple, quantitative, and sensitive surrogate indicator of the presence of prions. The reliable and sensitive detection of prions in plasma will enable a wide variety of applications in basic prion research and diagnostics.
THURSDAY, JANUARY 30, 2020
Docket Number: FDA-2012-D-0307 Recommendations to Reduce the Possible Risk of Transmission of Creutzfeldt-Jakob Disease and Variant Creutzfeldt-Jakob Disease by Blood and Blood Components; Draft Guidance for Industry Draft Guidance for Industry Singeltary Submission
FRIDAY, JANUARY 31, 2020
CJD TSE Prion Blood Products, iatrogenic transmission, Confucius is confused again, WHAT IF? Docket Number: FDA-2012-D-0307
PRION 2018 CONFERENCE
P98 The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge
Greenlee JJ (1), Moore SJ (1), and West Greenlee MH (2) (1) United States Department of Agriculture, Agricultural Research Service, National Animal Disease Center, Virus and Prion Research Unit, Ames, IA, United States (2) Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, United States.
reading up on this study from Prion 2018 Conference, very important findings ;
***> This study demonstrates that the H-type BSE agent is transmissible by the oronasal route.
***> These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
PRION 2018 CONFERENCE ABSTRACT
P98 The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge Greenlee JJ (1), Moore SJ (1), and West Greenlee MH (2) (1) United States Department of Agriculture, Agricultural Research Service, National Animal Disease Center, Virus and Prion Research Unit, Ames, IA, United States (2) Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, United States.
In 2006, a case of H-type bovine spongiform encephalopathy (BSE) was reported in a cow with a previously unreported prion protein polymorphism (E211K).
The E211K polymorphism is heritable and homologous to the E200K mutation in humans that is the most frequent PRNP mutation associated with familial Creutzfeldt-Jakob disease.
Although the prevalence of the E211K polymorphism is low, cattle carrying the K211 allele develop H-type BSE with a rapid onset after experimental inoculation by the intracranial route.
The purpose of this study was to investigate whether the agents of H-type BSE or H-type BSE associated with the E211K polymorphism transmit to wild type cattle or cattle with the K211 allele after oronasal exposure.
Wild type (EE211) or heterozygous (EK211) cattle were oronasally inoculated with either H-type BSE from the 2004 US Htype BSE case (n=3) or from the 2006 US H-type case associated with the E211K polymorphism (n=4) using 10% w/v brain homogenates.
Cattle were observed daily throughout the course of the experiment for the development of clinical signs.
At approximately 50 months post-inoculation, one steer (EK211 inoculated with E211K associated H-BSE) developed clinical signs including inattentiveness, loss of body condition, weakness, ataxia, and muscle fasciculations and was euthanized.
Enzyme immunoassay confirmed that abundant misfolded protein was present in the brainstem, and immunohistochemistry demonstrated PrPSc throughout the brain.
Western blot analysis of brain tissue from the clinically affected steer was consistent with the E211K H-type BSE inoculum.
With the experiment currently at 55 months post-inoculation, no other cattle in this study have developed clinical signs suggestive of prion disease. 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.
WEDNESDAY, AUGUST 15, 2018
***> The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge
PLOS ONE Journal
IBNC Tauopathy or TSE Prion disease, it appears, no one is sure
Terry S. Singeltary Sr., 03 Jul 2015 at 16:53 GMT
***however in 1 C-type challenged animal, Prion 2015 Poster Abstracts S67 PrPsc was not detected using rapid tests for BSE.
***Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.
*** IBNC Tauopathy or TSE Prion disease, it appears, no one is sure ***
http://www.plosone.org/annotation/listThread.action?root=86610
***Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.
*** IBNC Tauopathy or TSE Prion disease, it appears, no one is sure ***
http://www.plosone.org/annotation/listThread.action?root=86610
*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics of BSE in Canada Singeltary reply ;
MONDAY, JANUARY 09, 2017
Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle
CDC Volume 23, Number 2—February 2017
*** Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
*** Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
TUESDAY, AUGUST 28, 2018
USDA finds BSE infection in Florida cow 08/28/18 6:43 PM
http://animalhealthreportpriontse..blogspot.com/2018/08/usda-finds-bse-infection-in-florida-cow.html
WEDNESDAY, AUGUST 29, 2018
USDA Announces Atypical Bovine Spongiform Encephalopathy Detection USDA 08/29/2018 10:00 AM EDT
WEDNESDAY, AUGUST 29, 2018
Transmissible Spongiform Encephalopathy TSE Prion Atypical BSE Confirmed Florida Update USA August 28, 2018
***> P.108: Successful oral challenge of adult cattle with classical BSE
Sandor Dudas1,*, Kristina Santiago-Mateo1, Tammy Pickles1, Catherine Graham2, and Stefanie Czub1 1Canadian Food Inspection Agency; NCAD Lethbridge; Lethbridge, Alberta, Canada; 2Nova Scotia Department of Agriculture; Pathology Laboratory; Truro, Nova Scotia, Canada
Classical Bovine spongiform encephalopathy (C-type BSE) is a feed- and food-borne fatal neurological disease which can be orally transmitted to cattle and humans. Due to the presence of contaminated milk replacer, it is generally assumed that cattle become infected early in life as calves and then succumb to disease as adults. Here we challenged three 14 months old cattle per-orally with 100 grams of C-type BSE brain to investigate age-related susceptibility or resistance. During incubation, the animals were sampled monthly for blood and feces and subjected to standardized testing to identify changes related to neurological disease. At 53 months post exposure, progressive signs of central nervous system disease were observed in these 3 animals, and they were euthanized. Two of the C-BSE animals tested strongly positive using standard BSE rapid tests, however in 1 C-type challenged animal, Prion 2015 Poster Abstracts S67 PrPsc was not detected using rapid tests for BSE. Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.
***Our study demonstrates susceptibility of adult cattle to oral transmission of classical BSE.
We are further examining explanations for the unusual disease presentation in the third challenged animal.
***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.
P.86: Estimating the risk of transmission of BSE and scrapie to ruminants and humans by protein misfolding cyclic amplification
Morikazu Imamura, Naoko Tabeta, Yoshifumi Iwamaru, and Yuichi Murayama
National Institute of Animal Health; Tsukuba, Japan
To assess the risk of the transmission of ruminant prions to ruminants and humans at the molecular level, we investigated the ability of abnormal prion protein (PrPSc) of typical and atypical BSEs (L-type and H-type) and typical scrapie to convert normal prion protein (PrPC) from bovine, ovine, and human to proteinase K-resistant PrPSc-like form (PrPres) using serial protein misfolding cyclic amplification (PMCA).
Six rounds of serial PMCA was performed using 10% brain homogenates from transgenic mice expressing bovine, ovine or human PrPC in combination with PrPSc seed from typical and atypical BSE- or typical scrapie-infected brain homogenates from native host species. In the conventional PMCA, the conversion of PrPC to PrPres was observed only when the species of PrPC source and PrPSc seed matched. However, in the PMCA with supplements (digitonin, synthetic polyA and heparin), both bovine and ovine PrPC were converted by PrPSc from all tested prion strains. On the other hand, human PrPC was converted by PrPSc from typical and H-type BSE in this PMCA condition.
Although these results were not compatible with the previous reports describing the lack of transmissibility of H-type BSE to ovine and human transgenic mice, 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.
P.170: Potential detection of oral transmission of H type atypical BSE in cattle using in vitro conversion
***P.170: Potential detection of oral transmission of H type atypical BSE in cattle using in vitro conversion
Sandor Dudas, John G Gray, Renee Clark, and Stefanie Czub Canadian Food Inspection Agency; Lethbridge, AB Canada
Keywords: Atypical BSE, oral transmission, RT-QuIC
The detection of bovine spongiform encephalopathy (BSE) has had a significant negative impact on the cattle industry worldwide. In response, governments took actions to prevent transmission and additional threats to animal health and food safety. While these measures seem to be effective for controlling classical BSE, the more recently discovered atypical BSE has presented a new challenge. To generate data for risk assessment and control measures, we have challenged cattle orally with atypical BSE to determine transmissibility and mis-folded prion (PrPSc) tissue distribution. Upon presentation of clinical symptoms, animals were euthanized and tested for characteristic histopathological changes as well as PrPSc deposition.
The H-type challenged animal displayed vacuolation exclusively in rostral brain areas but the L-type challenged animal showed no evidence thereof. To our surprise, neither of the animals euthanized, which were displaying clinical signs indicative of BSE, showed conclusive mis-folded prion accumulation in the brain or gut using standard molecular or immunohistochemical assays. To confirm presence or absence of prion infectivity, we employed an optimized real-time quaking induced conversion (RT-QuIC) assay developed at the Rocky Mountain Laboratory, Hamilton, USA.
Detection of PrPSc was unsuccessful for brain samples tests from the orally inoculated L type animal using the RT-QuIC. It is possible that these negative results were related to the tissue sampling locations or that type specific optimization is needed to detect PrPSc in this animal. We were however able to consistently detect the presence of mis-folded prions in the brain of the H-type inoculated animal. Considering the negative and inconclusive results with other PrPSc detection methods, positive results using the optimized RT-QuIC suggests the method is extremely sensitive for H-type BSE detection. This may be evidence of the first successful oral transmission of H type atypical BSE in cattle and additional investigation of samples from these animals are ongoing.
Detection of PrPBSE and prion infectivity in the ileal Peyer’s patch of young calves as early as 2 months after oral challenge with classical bovine spongiform encephalopathy
Ivett Ackermann1 , Anne Balkema‑Buschmann1 , Reiner Ulrich2 , Kerstin Tauscher2 , James C. Shawulu1 , Markus Keller1 , Olanrewaju I. Fatola1 , Paul Brown3 and Martin H. Groschup1*
Abstract
In classical bovine spongiform encephalopathy (C-BSE), an orally acquired prion disease of cattle, the ileal Peyer’s patch (IPP) represents the main entry port for the BSE agent. In earlier C-BSE pathogenesis studies, cattle at 4–6 months of age were orally challenged, while there are strong indications that the risk of infection is highest in young animals. In the present study, unweaned calves aged 4–6 weeks were orally challenged to determine the earli‑ est time point at which newly formed PrPBSE and BSE infectivity are detectable in the IPP. For this purpose, calves were culled 1 week as well as 2, 4, 6 and 8 months post-infection (mpi) and IPPs were examined for BSE infectivity using a bovine PrP transgenic mouse bioassay, and for PrPBSE by immunohistochemistry (IHC) and protein misfolding cyclic amplifcation (PMCA) assays. For the frst time, BSE prions were detected in the IPP as early as 2 mpi by transgenic mouse bioassay and PMCA and 4 mpi by IHC in the follicular dendritic cells (FDCs) of the IPP follicles. These data indi‑ cate that BSE prions propagate in the IPP of unweaned calves within 2 months of oral uptake of the agent.
In summary, our study demonstrates for the frst time PrPBSE (by PMCA) and prion infectivity (by mouse bioassay) in the ileal Peyer’s patch (IPP) of young calves as early as 2 months after infection. From 4 mpi nearly all calves showed PrPBSE positive IPP follicles (by IHC), even with PrPBSE accumulation detectable in FDCs in some animals. Finally, our results confrm the IPP as the early port of entry for the BSE agent and a site of initial propagation of PrPBSE and infectivity during the early pathogenesis of the disease. Terefore, our study supports the recommendation to remove the last four metres of the small intestine (distal ileum) at slaughter, as designated by current legal requirements for countries with a controlled BSE risk status, as an essential measure for consumer and public health protection.
A study comparing preclinical cattle infected naturally with BSE to clinically affected cattle either naturally or experimentally infected with BSE by the oral route found the most abundant PrPSc in the brainstem area (39), which is consistent with ascension to the brain from the gut by sympathetic and parasympathetic projections (40). In our experiment, abundant prions were observed in the brainstem of cattle with clinical signs of BSE, which is similar to the amount in their thalamus or midbrain regions. Interestingly, prions in the brainstem of cattle with clinical evidence of BSE seeded the RT-QuIC reactions faster than any other brain region despite the brainstem area having lower EIA OD values (Table 2) in comparison to other brain regions. This suggests that higher concentrations of prions do not necessarily seed the reaction faster. Perhaps prions of the brainstem exist in a preferred conformation for better conversion despite being present in lower concentrations.
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MONDAY, MAY 20, 2019
Tracking and clarifying differential traits of classical- and atypical L-type bovine spongiform encephalopathy prions after transmission from cattle to cynomolgus monkeys
SUNDAY, APRIL 14, 2019
Estimation of prion infectivity in tissues of cattle infected with atypical BSE by real time-quaking induced conversion assay
WEDNESDAY, APRIL 24, 2019
USDA Announces Atypical Bovine Spongiform Encephalopathy Detection Aug 29, 2018 A Review of Science 2019
WEDNESDAY, JULY 31, 2019
The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L
O.4.3
Spread of BSE prions in cynomolgus monkeys (Macaca fascicularis) after oral transmission
Edgar Holznagel1, Walter Schulz-Schaeffer2, Barbara Yutzy1, Gerhard Hunsmann3, Johannes Loewer1 1Paul-Ehrlich-Institut, Federal Institute for Sera and Vaccines, Germany; 2Department of Neuropathology, Georg-August University, Göttingen, Germany, 3Department of Virology and Immunology, German Primate Centre, Göttingen, Germany
Background: BSE-infected cynomolgus monkeys represent a relevant animal model to study the pathogenesis of variant Creutzfeldt-Jacob disease (vCJD).
Objectives: To study the spread of BSE prions during the asymptomatic phase of infection in a simian animal model.
Methods: Orally BSE-dosed macaques (n=10) were sacrificed at defined time points during the incubation period and 7 orally BSE-dosed macaques were sacrificed after the onset of clinical signs. Neuronal and non-neuronal tissues were tested for the presence of proteinase-K-resistant prion protein (PrPres) by western immunoblot and by paraffin-embedded tissue (PET) blot technique.
Results: In clinically diseased macaques (5 years p.i. + 6 mo.), PrPres deposits were widely spread in neuronal tissues (including the peripheral sympathetic and parasympathetic nervous system) and in lymphoid tissues including tonsils. In asymptomatic disease carriers, PrPres deposits could be detected in intestinal lymph nodes as early as 1 year p.i., but CNS tissues were negative until 3 – 4 years p.i. Lumbal/sacral segments of the spinal cord and medulla oblongata were PrPres positive as early as 4.1 years p.i., whereas sympathetic trunk and all thoracic/cervical segments of the spinal cord were still negative for PrPres. However, tonsil samples were negative in all asymptomatic cases.
Discussion: There is evidence for an early spread of BSE to the CNS via autonomic fibres of the splanchnic and vagus nerves indicating that trans-synaptical spread may be a time-limiting factor for neuroinvasion. Tonsils were predominantly negative during the main part of the incubation period indicating that epidemiological vCJD screening results based on the detection of PrPres in tonsil biopsies may mostly tend to underestimate the prevalence of vCJD among humans.
P.4.23
Transmission of atypical BSE in humanized mouse models
Liuting Qing1, Wenquan Zou1, Cristina Casalone2, Martin Groschup3, Miroslaw Polak4, Maria Caramelli2, Pierluigi Gambetti1, Juergen Richt5, Qingzhong Kong1 1Case Western Reserve University, USA; 2Instituto Zooprofilattico Sperimentale, Italy; 3Friedrich-Loeffler-Institut, Germany; 4National Veterinary Research Institute, Poland; 5Kansas State University (Previously at USDA National Animal Disease Center), USA
Background: Classical BSE is a world-wide prion disease in cattle, and the classical BSE strain (BSE-C) has led to over 200 cases of clinical human infection (variant CJD). Atypical BSE cases have been discovered in three continents since 2004; they include the L-type (also named BASE), the H-type, and the first reported case of naturally occurring BSE with mutated bovine PRNP (termed BSE-M). The public health risks posed by atypical BSE were largely undefined.
Objectives: To investigate these atypical BSE types in terms of their transmissibility and phenotypes in humanized mice. Methods: Transgenic mice expressing human PrP were inoculated with several classical (C-type) and atypical (L-, H-, or Mtype) BSE isolates, and the transmission rate, incubation time, characteristics and distribution of PrPSc, symptoms, and histopathology were or will be examined and compared.
Results: Sixty percent of BASE-inoculated humanized mice became infected with minimal spongiosis and an average incubation time of 20-22 months, whereas only one of the C-type BSE-inoculated mice developed prion disease after more than 2 years. Protease-resistant PrPSc in BASE-infected humanized Tg mouse brains was biochemically different from bovine BASE or sCJD. PrPSc was also detected in the spleen of 22% of BASE-infected humanized mice, but not in those infected with sCJD. Secondary transmission of BASE in the humanized mice led to a small reduction in incubation time. The atypical BSE-H strain is also transmissible with distinct phenotypes in the humanized mice, but no BSE-M transmission has been observed so far.
Discussion: Our results demonstrate that BASE is more virulent than classical BSE, has a lymphotropic phenotype, and displays a modest transmission barrier in our humanized mice.
BSE-H is also transmissible in our humanized Tg mice.
The possibility of more than two atypical BSE strains will be discussed.
Supported by NINDS NS052319, NIA AG14359, and NIH AI 77774.
P03.137
Transmission of BSE to Cynomolgus Macaque, a Non-human Primate; Development of Clinical Symptoms and Tissue Distribution of PrPSC
Yamakawa, Y1; Ono, F2; Tase, N3; Terao, K3; Tannno, J3; Wada, N4; Tobiume, M5; Sato, Y5; Okemoto-Nakamura, Y1; Hagiwara, K1; Sata, T5 1National Institure of Infectious diseases, Cell biology and Biochemistry, Japan; 2Corporation for Production and Research Laboratory Primates., Japan; 3National Institure of Biomedical Innovation, Tsukuba Primate Reserch Center, Japan; 4Yamauchi Univ., Veterinary Medicine, Japan; 5National Institure of Infectious diseases, Pathology, Japan
Two of three cynomolgus monkeys developed abnormal neuronal behavioral signs at 30-(#7) and 28-(#10) months after intracerebral inoculation of 200ul of 10% brain homogenates of BSE affected cattle (BSE/JP6). Around 30 months post inoculation (mpi), they developed sporadic anorexia and hyperekplexia with squeal against environmental stimulations such as light and sound. Tremor, myoclonic jerk and paralysis became conspicuous during 32 to 33-mpi, and symptoms become worsened according to the disease progression. Finally, one monkey (#7) fell into total paralysis at 36-mpi. This monkey was sacrificed at 10 days after intensive veterinary care including infusion and per oral supply of liquid food. The other monkey (#10) had to grasp the cage bars to keep an upright posture caused by the sever ataxia. This monkey was sacrificed at 35-mpi. EEG of both monkeys showed diffuse slowing. PSD characteristic for sporadic CJD was not observed in both monkeys. The result of forearm movement test showed the hypofunction that was observed at onset of clinical symptoms. Their cognitive function determined by finger maze test was maintained at the early stage of sideration. However, it was rapidly impaired followed by the disease progression. Their autopsied tissues were immunochemically investigated for the tissue distribution of PrPSc. Severe spongiform change in the brain together with heavy accumulation of PrPSc having the type 2B/4 glycoform profile confirmed successful transmission of BSE to Cynomolgus macaques. Granular and linear deposition of PrPSC was detected by IHC in the CNS of both monkeys. At cerebral cortex, PrPSC was prominently accumulated in the large plaques. Sparse accumulation of PrPSc was detected in several peripheral nerves of #7 but not in #10 monkey, upon the WB analysis. Neither #7 nor #10 monkey accumulated detectable amounts of PrPSc in their lymphatic organs such as tonsil, spleen, adrenal grands and thymus although PrPSc was barely detected in the submandibular lymph node of #7 monkey. Such confined tissue distribution of PrPSc after intracerebral infection with BSE agent is not compatible to that reported on the Cynomolgus macaques infected with BSE by oral or intra-venous (intra-peritoneal) routs, in which PrPSc was accumulated at not only CNS but also widely distributed lymphatic tissues.
P04.27
Experimental BSE Infection of Non-human Primates: Efficacy of the Oral Route
Holznagel, E1; Yutzy, B1; Deslys, J-P2; Lasmézas, C2; Pocchiari, M3; Ingrosso, L3; Bierke, P4; Schulz-Schaeffer, W5; Motzkus, D6; Hunsmann, G6; Löwer, J1 1Paul-Ehrlich-Institut, Germany; 2Commissariat à l´Energie Atomique, France; 3Instituto Superiore di Sanità, 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).http://www.neuroprion.org/resources/pdf_docs/conferences/prion2007/abstract_book.pdf
Simian vCJD can be easily triggered in cynomolgus monkeys on the oral route using less than 5 g BSE brain homogenate.
WE know now, and we knew decades ago, that 5.5 grams of suspect feed in TEXAS was enough to kill 100 cows.
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 Lasmézas, Emmanuel Comoy, Stephen Hawkins, Christian Herzog, Franck Mouthon, Timm Konold, Frédéric Auvré, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Nicole Salès, 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.
snip...
BSE bovine brain inoculum
100 g 10 g 5 g 1 g 100 mg 10 mg 1 mg 0·1 mg 0·01 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 intraperitoneal.
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.
it is clear that the designing scientists must have also shared Mr Bradleyâs surprise at the results because all the dose levels right down to 1 gram triggered infection.
I ask Professor Kong ;
Thursday, December 04, 2008 3:37 PM
Subject: RE: re--Chronic Wating Disease (CWD) and Bovine Spongiform Encephalopathies (BSE): Public Health Risk Assessment
IS the h-BSE more virulent than typical BSE as well, or the same as cBSE, or less virulent than cBSE? just curious.....
Professor Kong reply ;
.....snip
As to the H-BSE, we do not have sufficient data to say one way or another, but we have found that H-BSE can infect humans. I hope we could publish these data once the study is complete. Thanks for your interest.
Best regards, Qingzhong Kong, PhD Associate Professor Department of Pathology Case Western Reserve University Cleveland, OH 44106 USA
P.4.23 Transmission of atypical BSE in humanized mouse models
Liuting Qing1, Wenquan Zou1, Cristina Casalone2, Martin Groschup3, Miroslaw Polak4, Maria Caramelli2, Pierluigi Gambetti1, Juergen Richt5, Qingzhong Kong1 1Case Western Reserve University, USA; 2Instituto Zooprofilattico Sperimentale, Italy; 3Friedrich-Loeffler-Institut, Germany; 4National Veterinary Research Institute, Poland; 5Kansas State University (Previously at USDA National Animal Disease Center), USA
Background: Classical BSE is a world-wide prion disease in cattle, and the classical BSE strain (BSE-C) has led to over 200 cases of clinical human infection (variant CJD). Atypical BSE cases have been discovered in three continents since 2004; they include the L-type (also named BASE), the H-type, and the first reported case of naturally occurring BSE with mutated bovine PRNP (termed BSE-M). The public health risks posed by atypical BSE were argely undefined.
Objectives: To investigate these atypical BSE types in terms of their transmissibility and phenotypes in humanized mice.
Methods: Transgenic mice expressing human PrP were inoculated with several classical (C-type) and atypical (L-, H-, or Mtype) BSE isolates, and the transmission rate, incubation time, characteristics and distribution of PrPSc, symptoms, and histopathology were or will be examined and compared.
Results: Sixty percent of BASE-inoculated humanized mice became infected with minimal spongiosis and an average incubation time of 20-22 months, whereas only one of the C-type BSE-inoculated mice developed prion disease after more than 2 years. Protease-resistant PrPSc in BASE-infected humanized Tg mouse brains was biochemically different from bovine BASE or sCJD. PrPSc was also detected in the spleen of 22% of BASE-infected humanized mice, but not in those infected with sCJD. Secondary transmission of BASE in the humanized mice led to a small reduction in incubation time. The atypical BSE-H strain is also transmissible with distinct phenotypes in the humanized mice, but no BSE-M transmission has been observed so far.
Discussion: Our results demonstrate that BASE is more virulent than classical BSE, has a lymphotropic phenotype, and displays a modest transmission barrier in our humanized mice. BSE-H is also transmissible in our humanized Tg mice. The possibility of more than two atypical BSE strains will be discussed.
Supported by NINDS NS052319, NIA AG14359, and NIH AI 77774.
see full text ;
>>> It is distinct from atypical BSE, which may develop spontaneously, according to information from the U.S. Centers for Disease Control and Prevention.
THIS IS A MYTH $$$
***atypical spontaneous BSE in France LOL***
FRANCE STOPS TESTING FOR MAD COW DISEASE BSE, and here’s why, to many spontaneous events of mad cow disease $$$
***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, March 24, 2016
FRANCE CONFIRMS BOVINE SPONGIFORM ENCEPHALOPATHY BSE MAD COW (ESB) chez une vache dans les Ardennes
***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 $$$
we have seen the spontaneous BSE epidemic in France, what about the other HIGH INCIDENCE ATYPICAL BSE COUNTRY OF POLAND, another atypical spontaneous event of high incidence. how can this be blamed on a happenstance of nothing, i.e. old age? goes against all junk science to date on the spontaneous atypical BSE i.e.
> In 2015, the OIE determined that atypical BSE occurred spontaneously at a low rate in all cattle populations and would be excluded for BSE risk. ...
>Atypical BSE occurs in older cattle, usually 8 years of age or greater, and does not appear to be associated with contaminated feed. Like classic or sporadic CJD in humans, it seems to arise rarely and spontaneously.
POLAND ATYPICAL BSE AND SPORADIC CJD
we have seen the spontaneous BSE epidemic in France, what about the other HIGH INCIDENCE ATYPICAL BSE COUNTRY OF POLAND, another atypical spontaneous event of high incidence. how can this be blamed on a happenstance of nothing, i.e. old age? goes against all junk science to date on the spontaneous atypical BSE i.e.
> In 2015, the OIE determined that atypical BSE occurred spontaneously at a low rate in all cattle populations and would be excluded for BSE risk. ...
>Atypical BSE occurs in older cattle, usually 8 years of age or greater, and does not appear to be associated with contaminated feed. Like classic or sporadic CJD in humans, it seems to arise rarely and spontaneously.
POLAND ATYPICAL BSE AND SPORADIC CJD
Atypical status of bovine spongiform encephalopathy in Poland: a molecular typing study
Summary
The aim of this study was to analyze molecular features of protease-resistant prion protein (PrPres) in Western blots of BSE cases diagnosed in Poland with respect to a possible atypical status. Confirmed cases were analyzed by Western blotting with several monoclonal antibodies directed at N-terminal and core epitopes of prion protein (PrP). Most cases showed the classical glycoprofile characterized by the dominance of the di- over the monoglycosylated PrPres band, yielding di-/mono- ratios well above 2 and by reactivity with antibodies having their epitopes in bovine PrP region 110–242 (C-type cases). Surprisingly, seven cases of BSE were atypical. Six were classified as L-type based on a slightly lower molecular mass (Mr) of the non- glycosylated band with respect to C-types and a conspicuously low di-/mono- ratio of glycosylated PrPres bands approaching unity. One case was classified as H-type because of a higher Mr of PrPres bands on the blot when compared with C-type cases. A characteristic epitope of H-type PrPres occurred in the 101–110 region of PrP for which only antibody 12B2 had a sufficient affinity. The occurrence of atypical cases only in animals 9 years of age and older raises questions about the mechanisms of prion diseases and the origin of BSE.
Atypical status of bovine spongiform encephalopathy in Poland: a molecular typing study
M. P. Polak1, J. F. Zmudzinski1, J. G. Jacobs2, J. P. M. Langeveld2
1 National Veterinary Research Institute, Pulawy, Poland
2 Central Institute for Animal Disease Control (CIDC-Lelystad), Lelystad, The Netherlands Received 24 April 2007; Accepted 27 August 2007; Published online 26 September 2007 # Springer-Verlag 2007
snip...
Clarification of whether these atypical cases represent genuine strains of BSE would be accomplished by transmission studies in mice. Such studies have already been performed in France, Germany and Italy [3, 5, 14, 15]. For H-type cases in France, successful transmission was achieved in both wild-type, and transgenic mice expressing bovine and ovine PrPC. In Germany, successful transmission of both an L-type and an H-type case to transgenic mice overexpressing bovine PrPC has been described. PrPres from those mice was identical to the inoculum used in the study, proving the existence of distinct strains of BSE. All atypical features of those isolates were maintained in the inoculated mice, indicating the existence of several prion strains in cattle, or alternatively a possible evolution to a single BSE strain, as suggested from data obtained by Capobianco et al. with wild-type inbred mice [15]. This second hypothesis could fit with data from the United Kingdom, where over 180,000 cases of BSE were diagnosed by passive surveillance. British and European experience based on tissue analysis from clinically affected animals showed consistent characteristics of BSE agent not only on histological sections from cattle brains but also when inoculating mice, pointing to the existence of one uniform strain of BSE. Therefore, it is possible that a sporadic form of BSE present in the cattle population at a very low rate in the past could have spread to naive animals via contaminated meatand-bone meals. Spontaneous BSE, if it occurs, must be a very rare phenomenon. However, data for Poland, where 14% of all cases comprised an atypical form of BSE, seems to be in contradiction to this hypothesis. But when the average age of all positive cases in Poland is taken into account, BSE is generally found in older animals (mean age of 7.7). Analysis of the age structure of cattle in Poland in the period of 2002–2006 shows that 56–60% of all animals were 7 years old and above. A much larger number of cattle should be tested to get better insight into the real prevalence of atypical BSE. However, current tendencies based on economic analysis point to a decrease in the number of tests performed rather than expanding this scheme any further. It would be sensible to maintain a certain level of testing focused on the older age group to distinguish between a stable, thus sporadic-based, situation of BSE, or alternatively a fade-out, thus epidemic-based, situation. Exploring the subject of spontaneous BSE in the cattle population may be ceased for economic reasons, and it may never be known while this answer is in our reach thanks to great financial efforts in recent years.
Poland is Proof atypical BSE is NOT an old cow spontaneous disease...tss
Number of reported cases of bovine spongiform encephalopathy (BSE) in farmed cattle worldwide* (excluding the United Kingdom) Country/Year
Poland
89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16
0 0 0 0 0 0 0 0 0 0 0 0 0 4f 5 11 19 10 9 5 4 2 1m 3 1 0 0 0
Source: USDA, APHIS, VS
What is the level of passenger traffic arriving in the United States from Poland?
A total of 188,946 passengers arrived at US airports on direct flights from Poland in fiscal year 2000.
An undetermined number of passengers arrived in the US from Poland via indirect flights.
Under APHIS-PPQ’s agricultural quarantine inspection monitoring, 451 air passengers from Poland were sampled for items of agricultural interest in fiscal year 2000.
Thirteen (13) of these passengers, or 2.9 percent, carried a total of 26.2 kg of meat items that could potentially harbor the pathogen(s) that cause BSE.
None of these passengers from whom meat items were confiscated reported plans to visit or work on a ranch or farm during their visit to the US.
Source: US Department of Transportation, and APHIS-PPQ Agricultural Quarantine Inspection data base CEI’s plans for follow up: CEI has no plans to provide additional information on this situation. If you need more information or wish to comment, you may contact Judy Akkina at (970) 490-7852 or Carol Tuszynski at (970) 490-7893.
What measures has USDA-APHIS taken to prevent the introduction of BSE? To prevent BSE from entering the United States, APHIS has restricted the importation of live ruminants and certain ruminant products from countries where BSE is known to exist.
Greetings FDA and public,
if you go to the below site, and search all BSE known countries and check out their air traffic illegal meat they have confiscated, and check out the low number checked, compared to actual passenger traffic, would not take too much for some nut to bring in FMD/TSEs into the USA as a 'suitcase bomb'.
[[Under APHIS-PPQ's agricultural quarantine inspection monitoring, 284 air passengers from Israel were sampled for items of agricultural interest in fiscal year 2001. Seven of these passengers, or 2 percent, carried a total of 11 kg of meat items that could potentially harbor the pathogen that causes BSE. None of these passengers from whom meat items were confiscated reported plans to visit or work on a ranch or farm during their visit to the U.S.]]
if they were to have questioned the terrorist that bombed the Twin Towers with jets, if they were to have questioned them at flight school in the USA, i am sure that they would have said they did not intend to visit the Twin Towers as a flying bomb either. what am i thinking, they probably did ask this? stupid me.
[[In 1999 a small amount of non-species specific meat and offal was imported and a small amount of fetal bovine serum (FBS) was also imported. FBS is considered to have a relatively low risk of transmitting BSE.]] more of the USA infamous 'non-species coding system', wonder how many of these species are capable of carrying a TSE?
snip...
A total of 524,401 passengers arrived on direct flights to the U.S. from Israel in fiscal year 2000. This number does not include passengers who arrived in the U.S. from Israel via indirect flights. Under APHIS-PPQ's agricultural quarantine inspection monitoring, 284 air passengers from Israel were sampled for items of agricultural interest in fiscal year 2001. Seven of these passengers, or 2 percent, carried a total of 11 kg of meat items that could potentially harbor the pathogen that causes BSE. None of these passengers from whom meat items were confiscated reported plans to visit or work on a ranch or farm during their visit to the U.S.
MONDAY, FEBRUARY 04, 2019
POLAND DETECTS BOVINE SPONGIFORM ENCEPHALOPATHY BSE TSE PRION
Poland is Proof atypical BSE is NOT an old cow spontaneous disease...tss
FRIDAY, FEBRUARY 01, 2019
Poland Exported 5,500 Pounds of Meat From Sick Cows to EU, what about mad cow disease?
Poland is Proof atypical BSE is NOT an old cow spontaneous disease...tss
WEDNESDAY, OCTOBER 24, 2018
Experimental Infection of Cattle With a Novel Prion Derived From Atypical H-Type Bovine Spongiform Encephalopathy
America BSE 589.2001 FEED REGULATIONS, BSE SURVEILLANCE, BSE TESTING, and CJD TSE Prion
***> cattle, pigs, sheep, cwd, tse, prion, oh my!
***> In contrast, cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions but no natural CWD infections in cattle have been reported (Sigurdson, 2008; Hamir et al., 2006).
Sheep and cattle may be exposed to CWD via common grazing areas with affected deer but so far, appear to be poorly susceptible to mule deer CWD (Sigurdson, 2008). In contrast, cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions but no natural CWD infections in cattle have been reported (Sigurdson, 2008; Hamir et al., 2006). It is not known how susceptible humans are to CWD but given that the prion can be present in muscle, it is likely that humans have been exposed to the agent via consumption of venison (Sigurdson, 2008). Initial experimental research suggests that human susceptibility to CWD is low and there may be a robust species barrier for CWD transmission to humans (Sigurdson, 2008), however the risk appetite for a public health threat may still find this level unacceptable.
cwd scrapie pigs oral routes
***> However, at 51 months of incubation or greater, 5 animals were positive by one or more diagnostic methods. Furthermore, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study) suggesting that swine are potential hosts for the agent of scrapie. <***
>*** Although the current U.S. feed ban is based on keeping tissues from TSE infected cattle from contaminating animal feed, swine rations in the U.S. could contain animal derived components including materials from scrapie infected sheep and goats. These results indicating the susceptibility of pigs to sheep scrapie, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health. <***
***> Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 5="" 6="" at="" by="" detected="" eia.="" examined="" group="" in="" intracranial="" least="" lymphoid="" month="" months="" of="" one="" pigs="" positive="" prpsc="" quic="" the="" tissues="" was="">6 months group, 5/6 pigs in the oral <6 4="" and="" group="" months="" oral="">6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%).
***> Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
snip.....
In the USA, under the Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law.
Animals considered at high risk for CWD include:
1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and
2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.
Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.
The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES. It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.
Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.
There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.
snip.....
36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011).
The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE).
Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison.
snip.....
The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).
snip.....
In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion.
snip.....
In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible... For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.
snip.....
Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.
snip.....
TUESDAY, APRIL 18, 2017
*** EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP ***
***> Wednesday, January 23, 2019
***> CFIA SFCR Guidance on Specified risk material (SRM) came into force on January 15, 2019 <***
Prion Conference 2018
O5 Prion Disease in Dromedary Camels
Babelhadj B (1), Di Bari MA (2), Pirisinu L (2), Chiappini B (2), Gaouar SB (3), Riccardi G (2), Marcon S (2), Agrimi U (2), Nonno R (2), Vaccari G (2) (1) École Normale Supérieure Ouargla. Laboratoire de protection des écosystèmes en zones arides et semi arides University Kasdi Merbah Ouargla, Ouargla, Algeria; (2) Istituto Superiore di Sanità, Department of Food Safety, Nutrition and Veterinary Public Health, Rome, Italy (3) University Abou Bekr Bélkaid, Tlemcen, Algeria.
Prions are responsible for fatal and transmissible neurodegenerative diseases including CreutzfeldtJakob disease in humans, scrapie in small ruminants and bovine spongiform encephalopathy (BSE). Following the BSE epidemic and the demonstration of its zoonotic potential, general concerns have been raised on animal prions.
Here we report the identification of a prion disease in dromedary camels (Camelus dromedarius) in Algeria and designate it as Camel Prion Disease (CPD). In the last years, neurological symptoms have been observed in adult male and female dromedaries presented for slaughter at the Ouargla abattoir. The symptoms include weight loss, behavioral abnormalities and neurological symptoms such as tremors, aggressiveness, hyper-reactivity, typical down and upwards movements of the head, hesitant and uncertain gait, ataxia of the hind limbs, occasional falls and difficult getting up. During 2015 and 2016, symptoms suggestive of prion disease were observed in 3.1% of 2259 dromedaries presented at ante-mortem examination. Laboratory diagnosis was obtained in three symptomatic dromedaries, sampled in 2016 and 2017, by the detection of typical neurodegeneration and disease-specific prion protein (PrPSc) in brain tissues.
Histopathological examination revealed spongiform change, gliosis and neuronal loss preferentially in grey matter of subcortical brain areas. Abundant PrPSc deposition was detected in the same brain areas by immunohistochemistry and PET-blot. Western blot analysis confirmed the presence of PK-resistant PrPSc, whose N-terminal cleaved PK-resistant core was characterized by a mono-glycosylated dominant form and by a distinctive N-terminal cleavage, different from that observed in BSE and scrapie.
PrPSc was also detected, by immunohistochemistry, in all sampled lymph nodes (cervical, prescapular and lumbar aortic) of the only animal from which they were collected.
The PRNP sequence of the two animals for which frozen material was available, showed 100% nucleotide identity with the PRNP sequence already reported for dromedary camel.
Overall, these data demonstrate the presence of a prion disease in dromedary camelswhose nature, origin and spread need further investigations. However, our preliminary observations on the rather high prevalence of symptomatic dromedaries and the involvement of lymphoid tissues, are consistent with CPD being an infectious disease. In conclusion, the emergence of a new prion disease in a livestock species of crucial importance for millions of people around the world, makes urgent to assess the risk for humans and to develop policies able to control the spread of the disease in animals and to minimize human exposure.
CDC
New Outbreak of TSE Prion in NEW LIVESTOCK SPECIES
Mad Camel Disease
Volume 24, Number 6—June 2018 Research
Prion Disease in Dromedary Camels, Algeria
Abstract
Prions cause fatal and transmissible neurodegenerative diseases, including Creutzfeldt-Jakob disease in humans, scrapie in small ruminants, and bovine spongiform encephalopathy (BSE). After the BSE epidemic, and the associated human infections, began in 1996 in the United Kingdom, general concerns have been raised about animal prions. We detected a prion disease in dromedary camels (Camelus dromedarius) in Algeria. Symptoms suggesting prion disease occurred in 3.1% of dromedaries brought for slaughter to the Ouargla abattoir in 2015–2016. We confirmed diagnosis by detecting pathognomonic neurodegeneration and disease-specific prion protein (PrPSc) in brain tissues from 3 symptomatic animals. Prion detection in lymphoid tissues is suggestive of the infectious nature of the disease. PrPSc biochemical characterization showed differences with BSE and scrapie. Our identification of this prion disease in a geographically widespread livestock species requires urgent enforcement of surveillance and assessment of the potential risks to human and animal health.
SNIP...
The possibility that dromedaries acquired the disease from eating prion-contaminated waste needs to be considered.
Tracing the origin of prion diseases is challenging. In the case of CPD, the traditional extensive and nomadic herding practices of dromedaries represent a formidable factor for accelerating the spread of the disease at long distances, making the path of its diffusion difficult to determine. Finally, the major import flows of live animals to Algeria from Niger, Mali, and Mauritania (27) should be investigated to trace the possible origin of CPD from other countries.
Camels are a vital animal species for millions of persons globally. The world camel population has a yearly growth rate of 2.1% (28). In 2014, the population was estimated at ≈28 million animals, but this number is probably underestimated.. Approximately 88% of camels are found in Africa, especially eastern Africa, and 12% are found in Asia. Official data reported 350,000 dromedaries in Algeria in 2014 (28).
On the basis of phenotypic traits and sociogeographic criteria, several dromedary populations have been suggested to exist in Algeria (29). However, recent genetic studies in Algeria and Egypt point to a weak differentiation of the dromedary population as a consequence of historical use as a cross-continental beast of burden along trans-Saharan caravan routes, coupled with traditional extensive/nomadic herding practices (30).
Such genetic homogeneity also might be reflected in PRNP. Studies on PRNP variability in camels are therefore warranted to explore the existence of genotypes resistant to CPD, which could represent an important tool for CPD management as it was for breeding programs for scrapie eradication in sheep.
In the past 10 years, the camel farming system has changed rapidly, with increasing setup of periurban dairy farms and dairy plants and diversification of camel products and market penetration (13). This evolution requires improved health standards for infectious diseases and, in light of CPD, for prion diseases.
The emergence of another prion disease in an animal species of crucial importance for millions of persons worldwide makes it necessary to assess the risk for humans and develop evidence-based policies to control and limit the spread of the disease in animals and minimize human exposure. The implementation of a surveillance system for prion diseases would be a first step to enable disease control and minimize human and animal exposure. Finally, the diagnostic capacity of prion diseases needs to be improved in all countries in Africa where dromedaries are part of the domestic livestock.
***> IMPORTS AND EXPORTS <***
***SEE MASSIVE AMOUNTS OF BANNED ANIMAL PROTEIN AKA MAD COW FEED IN COMMERCE USA DECADES AFTER POST BAN ***
SATURDAY, JUNE 1, 2019
***> Traceability of animal protein byproducts in ruminants by multivariate analysis of isotope ratio mass spectrometry to prevent transmission of prion diseases
ZOONOSIS OF SCRAPIE TSE PRION
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases).
Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
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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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***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online
Taylor & Francis
Prion 2016 Animal Prion Disease Workshop Abstracts
WS-01: Prion diseases in animals and zoonotic potential
Juan Maria Torres a, Olivier Andreoletti b, J uan-Carlos Espinosa a. Vincent Beringue c. Patricia Aguilar a,
Natalia Fernandez-Borges a. and Alba Marin-Moreno a
"Centro de Investigacion en Sanidad Animal ( CISA-INIA ). Valdeolmos, Madrid. Spain; b UMR INRA -ENVT 1225 Interactions Holes Agents Pathogenes. ENVT. Toulouse. France: "UR892. Virologie lmmunologie MolécuIaires, Jouy-en-Josas. France
Dietary exposure to bovine spongiform encephalopathy (BSE) contaminated bovine tissues is considered as the origin of variant Creutzfeldt Jakob (vCJD) disease in human. To date, BSE agent is the only recognized zoonotic prion... Despite the variety of Transmissible Spongiform Encephalopathy (TSE) agents that have been circulating for centuries in farmed ruminants there is no apparent epidemiological link between exposure to ruminant products and the occurrence of other form of TSE in human like sporadic Creutzfeldt Jakob Disease (sCJD). However, the zoonotic potential of the diversity of circulating TSE agents has never been systematically assessed. The major issue in experimental assessment of TSEs zoonotic potential lies in the modeling of the ‘species barrier‘, the biological phenomenon that limits TSE agents’ propagation from a species to another. In the last decade, mice genetically engineered to express normal forms of the human prion protein has proved essential in studying human prions pathogenesis and modeling the capacity of TSEs to cross the human species barrier.
To assess the zoonotic potential of prions circulating in farmed ruminants, we study their transmission ability in transgenic mice expressing human PrPC (HuPrP-Tg). Two lines of mice expressing different forms of the human PrPC (129Met or 129Val) are used to determine the role of the Met129Val dimorphism in susceptibility/resistance to the different agents.
These transmission experiments confirm the ability of BSE prions to propagate in 129M- HuPrP-Tg mice and demonstrate that Met129 homozygotes may be susceptible to BSE in sheep or goat to a greater degree than the BSE agent in cattle and that these agents can convey molecular properties and neuropathological indistinguishable from vCJD. However homozygous 129V mice are resistant to all tested BSE derived prions independently of the originating species suggesting a higher transmission barrier for 129V-PrP variant.
Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
***> why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man.
***> I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough.
***> Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
snip...
R. BRADLEY
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
***> Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility. <***
Transmission of scrapie prions to primate after an extended silent incubation period
Emmanuel E. Comoy, Jacqueline Mikol, Sophie Luccantoni-Freire, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Valérie Durand, Capucine Dehen, Olivier Andreoletti, Cristina Casalone, Juergen A. Richt, Justin J. Greenlee, Thierry Baron, Sylvie L. Benestad, Paul Brown & Jean-Philippe Deslys Scientific Reports volume 5, Article number: 11573 (2015) | Download Citation
Abstract
Classical bovine spongiform encephalopathy (c-BSE) is the only animal prion disease reputed to be zoonotic, causing variant Creutzfeldt-Jakob disease (vCJD) in humans and having guided protective measures for animal and human health against animal prion diseases. Recently, partial transmissions to humanized mice showed that the zoonotic potential of scrapie might be similar to c-BSE. We here report the direct transmission of a natural classical scrapie isolate to cynomolgus macaque, a highly relevant model for human prion diseases, after a 10-year silent incubation period, with features similar to those reported for human cases of sporadic CJD. Scrapie is thus actually transmissible to primates with incubation periods compatible with their life expectancy, although fourfold longer than BSE. Long-term experimental transmission studies are necessary to better assess the zoonotic potential of other prion diseases with high prevalence, notably Chronic Wasting Disease of deer and elk and atypical/Nor98 scrapie.
SNIP...
Discussion We describe the transmission of spongiform encephalopathy in a non-human primate inoculated 10 years earlier with a strain of sheep c-scrapie. Because of this extended incubation period in a facility in which other prion diseases are under study, we are obliged to consider two alternative possibilities that might explain its occurrence. We first considered the possibility of a sporadic origin (like CJD in humans). Such an event is extremely improbable because the inoculated animal was 14 years old when the clinical signs appeared, i.e. about 40% through the expected natural lifetime of this species, compared to a peak age incidence of 60–65 years in human sporadic CJD, or about 80% through their expected lifetimes. Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.
The second possibility is a laboratory cross-contamination. Three facts make this possibility equally unlikely. First, handling of specimens in our laboratory is performed with fastidious attention to the avoidance of any such cross-contamination. Second, no laboratory cross-contamination has ever been documented in other primate laboratories, including the NIH, even between infected and uninfected animals housed in the same or adjacent cages with daily intimate contact (P. Brown, personal communication). Third, the cerebral lesion profile is different from all the other prion diseases we have studied in this model19, with a correlation between cerebellar lesions (massive spongiform change of Purkinje cells, intense PrPres staining and reactive gliosis26) and ataxia. The iron deposits present in the globus pallidus are a non specific finding that have been reported previously in neurodegenerative diseases and aging27. Conversely, the thalamic lesion was reminiscent of a metabolic disease due to thiamine deficiency28 but blood thiamine levels were within normal limits (data not shown). The preferential distribution of spongiform change in cortex associated with a limited distribution in the brainstem is reminiscent of the lesion profile in MM2c and VV1 sCJD patients29, but interspecies comparison of lesion profiles should be interpreted with caution. It is of note that the same classical scrapie isolate induced TSE in C57Bl/6 mice with similar incubation periods and lesional profiles as a sample derived from a MM1 sCJD patient30.
We are therefore confident that the illness in this cynomolgus macaque represents a true transmission of a sheep c-scrapie isolate directly to an old-world monkey, which taxonomically resides in the primate subdivision (parvorder of catarrhini) that includes humans. With an homology of its PrP protein with humans of 96.4%31, cynomolgus macaque constitutes a highly relevant model for assessing zoonotic risk of prion diseases. Since our initial aim was to show the absence of transmission of scrapie to macaques in the worst-case scenario, we obtained materials from a flock of naturally-infected sheep, affecting animals with different genotypes32. This c-scrapie isolate exhibited complete transmission in ARQ/ARQ sheep (332 ± 56 days) and Tg338 transgenic mice expressing ovine VRQ/VRQ prion protein (220 ± 5 days) (O. Andreoletti, personal communication). From the standpoint of zoonotic risk, it is important to note that sheep with c-scrapie (including the isolate used in our study) have demonstrable infectivity throughout their lymphoreticular system early in the incubation period of the disease (3 months-old for all the lymphoid organs, and as early as 2 months-old in gut-associated lymph nodes)33. In addition, scrapie infectivity has been identified in blood34, milk35 and skeletal muscle36 from asymptomatic but scrapie infected small ruminants which implies a potential dietary exposure for consumers.
Two earlier studies have reported the occurrence of clinical TSE in cynomolgus macaques after exposures to scrapie isolates. In the first study, the “Compton” scrapie isolate (derived from an English sheep) and serially propagated for 9 passages in goats did not transmit TSE in cynomolgus macaque, rhesus macaque or chimpanzee within 7 years following intracerebral challenge1; conversely, after 8 supplementary passages in conventional mice, this “Compton” isolate induced TSE in a cynomolgus macaque 5 years after intracerebral challenge, but rhesus macaques and chimpanzee remained asymptomatic 8.5 years post-exposure8. However, multiple successive passages that are classically used to select laboratory-adapted prion strains can significantly modify the initial properties of a scrapie isolate, thus questioning the relevance of zoonotic potential for the initial sheep-derived isolate. The same isolate had also induced disease into squirrel monkeys (new-world monkey)9. A second historical observation reported that a cynomolgus macaque developed TSE 6 years post-inoculation with brain homogenate from a scrapie-infected Suffolk ewe (derived from USA), whereas a rhesus macaque and a chimpanzee exposed to the same inoculum remained healthy 9 years post-exposure1. This inoculum also induced TSE in squirrel monkeys after 4 passages in mice. Other scrapie transmission attempts in macaque failed but had more shorter periods of observation in comparison to the current study. Further, it is possible that there are differences in the zoonotic potential of different scrapie strains.
The most striking observation in our study is the extended incubation period of scrapie in the macaque model, which has several implications. Firstly, our observations constitute experimental evidence in favor of the zoonotic potential of c-scrapie, at least for this isolate that has been extensively studied32,33,34,35,36. The cross-species zoonotic ability of this isolate should be confirmed by performing duplicate intracerebral exposures and assessing the transmissibility by the oral route (a successful transmission of prion strains through the intracerebral route may not necessarily indicate the potential for oral transmission37). However, such confirmatory experiments may require more than one decade, which is hardly compatible with current general management and support of scientific projects; thus this study should be rather considered as a case report.
Secondly, transmission of c-BSE to primates occurred within 8 years post exposure for the lowest doses able to transmit the disease (the survival period after inoculation is inversely proportional to the initial amount of infectious inoculum). The occurrence of scrapie 10 years after exposure to a high dose (25 mg) of scrapie-infected sheep brain suggests that the macaque has a higher species barrier for sheep c-scrapie than c-BSE, although it is notable that previous studies based on in vitro conversion of PrP suggested that BSE and scrapie prions would have a similar conversion potential for human PrP38.
Thirdly, prion diseases typically have longer incubation periods after oral exposure than after intracerebral inoculations: since humans can develop Kuru 47 years after oral exposure39, an incubation time of several decades after oral exposure to scrapie would therefore be expected, leading the disease to occur in older adults, i.e. the peak age for cases considered to be sporadic disease, and making a distinction between scrapie-associated and truly sporadic disease extremely difficult to appreciate.
Fourthly, epidemiologic evidence is necessary to confirm the zoonotic potential of an animal disease suggested by experimental studies. A relatively short incubation period and a peculiar epidemiological situation (e.g., all the first vCJD cases occurring in the country with the most important ongoing c-BSE epizootic) led to a high degree of suspicion that c-BSE was the cause of vCJD. Sporadic CJD are considered spontaneous diseases with an almost stable and constant worldwide prevalence (0.5–2 cases per million inhabitants per year), and previous epidemiological studies were unable to draw a link between sCJD and classical scrapie6,7,40,41, even though external causes were hypothesized to explain the occurrence of some sCJD clusters42,43,44. However, extended incubation periods exceeding several decades would impair the predictive values of epidemiological surveillance for prion diseases, already weakened by a limited prevalence of prion diseases and the multiplicity of isolates gathered under the phenotypes of “scrapie” and “sporadic CJD”.
Fifthly, considering this 10 year-long incubation period, together with both laboratory and epidemiological evidence of decade or longer intervals between infection and clinical onset of disease, no premature conclusions should be drawn from negative transmission studies in cynomolgus macaques with less than a decade of observation, as in the aforementioned historical transmission studies of scrapie to primates1,8,9. Our observations and those of others45,46 to date are unable to provide definitive evidence regarding the zoonotic potential of CWD, atypical/Nor98 scrapie or H-type BSE. The extended incubation period of the scrapie-affected macaque in the current study also underscores the limitations of rodent models expressing human PrP for assessing the zoonotic potential of some prion diseases since their lifespan remains limited to approximately two years21,47,48. This point is illustrated by the fact that the recently reported transmission of scrapie to humanized mice was not associated with clinical signs for up to 750 days and occurred in an extreme minority of mice with only a marginal increase in attack rate upon second passage13. The low attack rate in these studies is certainly linked to the limited lifespan of mice compared to the very long periods of observation necessary to demonstrate the development of scrapie. Alternatively, one could estimate that a successful second passage is the result of strain adaptation to the species barrier, thus poorly relevant of the real zoonotic potential of the original scrapie isolate of sheep origin49. The development of scrapie in this primate after an incubation period compatible with its lifespan complements the study conducted in transgenic (humanized) mice; taken together these studies suggest that some isolates of sheep scrapie can promote misfolding of the human prion protein and that scrapie can develop within the lifespan of some primate species.
In addition to previous studies on scrapie transmission to primate1,8,9 and the recently published study on transgenic humanized mice13, our results constitute new evidence for recommending that the potential risk of scrapie for human health should not be dismissed. Indeed, human PrP transgenic mice and primates are the most relevant models for investigating the human transmission barrier. To what extent such models are informative for measuring the zoonotic potential of an animal TSE under field exposure conditions is unknown. During the past decades, many protective measures have been successfully implemented to protect cattle from the spread of c-BSE, and some of these measures have been extended to sheep and goats to protect from scrapie according to the principle of precaution. Since cases of c-BSE have greatly reduced in number, those protective measures are currently being challenged and relaxed in the absence of other known zoonotic animal prion disease. We recommend that risk managers should be aware of the long term potential risk to human health of at least certain scrapie isolates, notably for lymphotropic strains like the classical scrapie strain used in the current study. Relatively high amounts of infectivity in peripheral lymphoid organs in animals infected with these strains could lead to contamination of food products produced for human consumption. Efforts should also be maintained to further assess the zoonotic potential of other animal prion strains in long-term studies, notably lymphotropic strains with high prevalence like CWD, which is spreading across North America, and atypical/Nor98 scrapie (Nor98)50 that was first detected in the past two decades and now represents approximately half of all reported cases of prion diseases in small ruminants worldwide, including territories previously considered as scrapie free... Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
THURSDAY, JANUARY 30, 2020
Docket Number: FDA-2012-D-0307 Recommendations to Reduce the Possible Risk of Transmission of Creutzfeldt-Jakob Disease and Variant Creutzfeldt-Jakob Disease by Blood and Blood Components; Draft Guidance for Industry Draft Guidance for Industry Singeltary Submission
Part 2 Singeltary submission
FRIDAY, JANUARY 31, 2020
CJD TSE Prion Blood Products, iatrogenic transmission, Confucius is confused again, WHAT IF? Docket Number: FDA-2012-D-0307
THURSDAY, JANUARY 23, 2020
USDA Consolidates Regulations for NAHLN Laboratory Testing USDA Animal and Plant Health Inspection Service sent this bulletin at 01/23/2020 02:15 PM EST
Terry S. Singeltary Sr.
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