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The Brazilian Bovine Spongiform Encephalopathy (BSE) Surveillance System detected two cases of atypical BSE, type H in two beef cows in meat plants in two different states–Minas Gerais and Mato Grosso.
The case in Minas Gerais was a 11-year-old beef cow destined for emergency slaughter in a slaughterhouse, while Mato Grosso case was a 10-year-old beef cow destined for emergency slaughter in a slaughterhouse.
The samples were sent to the OIE Reference Laboratory for BSE at the Canadian Food Inspection Agency in Lethbridge, Alberta. The results of the confirmatory test were obtained on September 3, 2021.
These are the fourth and fifth cases of atypical BSE identified during 23 years of surveillance in Brazil. The last case was detected in 2019.
The meat and other products of these animals will not enter the food chain and do not represent a risk to ruminant populations.
BSE (bovine spongiform encephalopathy) is a progressive neurological disorder of cattle. BSE has been called “mad cow disease.”
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Many times media portrays atypical BSE strains as a spontaneous or sporadic event caused by old age. Sciences has shown us otherwise. All atypical BSE cases are not sporadic/spontaneous, OIE has recognized this. Atypical BSE is a risk factor for feed, science has shown us this, we must now recognize this risk factor in the FDA 589.2001 BSE feed regulatory system, we must also bring awareness…terry
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;
http://web.oie.int/downld/PROC2020/A_SCAD_Sept2019.pdf
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.
https://www.oie.int/fileadmin/SST/adhocreports/Bovine%20spongiform%20encephalopathy/AN/A_AhG_BSEsurv_RiskAss_Mar2019.pdf
***> Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
***> 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.
***> 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.
Emerg Infect Dis. 2017 Feb; 23(2): 284–287. doi: 10.3201/eid2302.161416 PMCID: PMC5324790 PMID: 28098532 Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle Hiroyuki Okada,corresponding author Yoshifumi Iwamaru, Morikazu Imamura, Kohtaro Miyazawa, Yuichi Matsuura, Kentaro Masujin, Yuichi Murayama, and Takashi Yokoyama Author information Copyright and License information Disclaimer This article has been cited by other articles in PMC. Go to: Abstract To determine oral transmissibility of the L-type bovine spongiform encephalopathy (BSE) prion, we orally inoculated 16 calves with brain homogenates of the agent. Only 1 animal, given a high dose, showed signs and died at 88 months. These results suggest low risk for oral transmission of the L-BSE agent among cattle.
Keywords: atypical bovine spongiform encephalopathy, cattle, L-type, prion, oral transmission, L-BSE, prions and related diseases, zoonoses The epidemic of bovine spongiform encephalopathy (BSE) in cattle is thought to be caused by oral infection through consumption of feed containing the BSE agent (prion). Since 2003, different neuropathologic and molecular phenotypes of BSE have been identified as causing ≈110 cases of atypical BSE worldwide, mainly in aged cattle. Although the etiology and pathogenesis of atypical BSE are not yet fully understood, atypical BSE prions possibly cause sporadic cases of BSE (1).
The L-type BSE (L-BSE) prion has been experimentally transmitted to cattle by intracerebral challenge, and the incubation period was is shorter than that for classical BSE (C-BSE) prions (2–6). The origin of transmissible mink encephalopathy in ranch-raised mink is thought to be caused by ingestion of L-BSE–infected material (7). Although L-BSE has been orally transmitted to mouse lemurs (8), it remains to be established whether L-BSE can be transmitted to cattle by oral infection. We therefore investigated the transmissibility of L-BSE by the oral route and tissue distribution of disease-associated prion protein (PrPSc) in cattle. All experiments involving animals were performed with the approval of the Animal Ethical Committee and the Animal Care and Use Committee of the National Institute of Animal Health (approval nos. 07–88 and 08–010).
snip…
The neuroanatomical PrPSc distribution pattern of orally challenged cattle differed somewhat from that described in cattle naturally and intracerebrally challenged with L-BSE (2–6,11,13,14), The conspicuous differences between the case we report and cases of natural and experimental infection are 1) higher amounts of PrPSc in the caudal medulla oblongata and the spinal cord coupled with that in the thalamus and the more rostral brainstem and 2) relatively low amounts of PrPSc in the cerebral cortices and the olfactory bulb. Furthermore, fewer PrPSc deposits in the dorsal motor nucleus of the vagus nerve may indicate that the parasympathetic retrogressive neuroinvasion pathway does not contribute to transport of the L-BSE prion from the gut to the brain, which is in contrast to the vagus-associated transport of the agent in C-BSE (15). PrPSc accumulation in the extracerebral tissues may be a result of centrifugal trafficking of the L-BSE prion from the central nervous system along somatic or autonomic nerve fibers rather than centripetal propagation of the agent (4,6,9). Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5324790/
Our study clearly confirms, experimentally, the potential risk for interspecies oral transmission of the agent of L-BSE. In our model, this risk appears higher than that for the agent of classical BSE, which could only be transmitted to mouse lemurs after a first passage in macaques (14). We report oral transmission of the L-BSE agent in young and adult primates. Transmission by the IC route has also been reported in young macaques (6,7). A previous study of L-BSE in transgenic mice expressing human PrP suggested an absence of any transmission barrier between cattle and humans for this particular strain of the agent of BSE, in contrast to findings for the agent of classical BSE (9). 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.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3310119/
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge
Author item Greenlee, Justin item MOORE, S – Orise Fellow item WEST-GREENLEE, M – Iowa State University
Submitted to: Prion
Publication Type: Abstract Only
Publication Acceptance Date: 5/14/2018
Publication Date: 5/22/2018
Citation: Greenlee, J.J., Moore, S.J., West Greenlee, M.H. 2018. The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge. Prion 2018, May 22-25, 2018, Santiago de Compostela, Spain. Paper No. P98, page 116. Interpretive Summary:
Technical Abstract: 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 H-type 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.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=353094
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.
PRION 2018 CONFERENCE ABSTRACT
Snip…
***> Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
***> 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.
***> 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.
Emerg Infect Dis. 2017 Feb; 23(2): 284–287. doi: 10.3201/eid2302.161416 PMCID: PMC5324790 PMID: 28098532 Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle Hiroyuki Okada,corresponding author Yoshifumi Iwamaru, Morikazu Imamura, Kohtaro Miyazawa, Yuichi Matsuura, Kentaro Masujin, Yuichi Murayama, and Takashi Yokoyama Author information Copyright and License information Disclaimer This article has been cited by other articles in PMC. Go to: Abstract To determine oral transmissibility of the L-type bovine spongiform encephalopathy (BSE) prion, we orally inoculated 16 calves with brain homogenates of the agent. Only 1 animal, given a high dose, showed signs and died at 88 months. These results suggest low risk for oral transmission of the L-BSE agent among cattle.
Keywords: atypical bovine spongiform encephalopathy, cattle, L-type, prion, oral transmission, L-BSE, prions and related diseases, zoonoses The epidemic of bovine spongiform encephalopathy (BSE) in cattle is thought to be caused by oral infection through consumption of feed containing the BSE agent (prion). Since 2003, different neuropathologic and molecular phenotypes of BSE have been identified as causing ≈110 cases of atypical BSE worldwide, mainly in aged cattle. Although the etiology and pathogenesis of atypical BSE are not yet fully understood, atypical BSE prions possibly cause sporadic cases of BSE (1).
The L-type BSE (L-BSE) prion has been experimentally transmitted to cattle by intracerebral challenge, and the incubation period was is shorter than that for classical BSE (C-BSE) prions (2–6). The origin of transmissible mink encephalopathy in ranch-raised mink is thought to be caused by ingestion of L-BSE–infected material (7). Although L-BSE has been orally transmitted to mouse lemurs (8), it remains to be established whether L-BSE can be transmitted to cattle by oral infection. We therefore investigated the transmissibility of L-BSE by the oral route and tissue distribution of disease-associated prion protein (PrPSc) in cattle. All experiments involving animals were performed with the approval of the Animal Ethical Committee and the Animal Care and Use Committee of the National Institute of Animal Health (approval nos. 07–88 and 08–010).
snip…
The neuroanatomical PrPSc distribution pattern of orally challenged cattle differed somewhat from that described in cattle naturally and intracerebrally challenged with L-BSE (2–6,11,13,14), The conspicuous differences between the case we report and cases of natural and experimental infection are 1) higher amounts of PrPSc in the caudal medulla oblongata and the spinal cord coupled with that in the thalamus and the more rostral brainstem and 2) relatively low amounts of PrPSc in the cerebral cortices and the olfactory bulb. Furthermore, fewer PrPSc deposits in the dorsal motor nucleus of the vagus nerve may indicate that the parasympathetic retrogressive neuroinvasion pathway does not contribute to transport of the L-BSE prion from the gut to the brain, which is in contrast to the vagus-associated transport of the agent in C-BSE (15). PrPSc accumulation in the extracerebral tissues may be a result of centrifugal trafficking of the L-BSE prion from the central nervous system along somatic or autonomic nerve fibers rather than centripetal propagation of the agent (4,6,9). Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5324790/
Our study clearly confirms, experimentally, the potential risk for interspecies oral transmission of the agent of L-BSE. In our model, this risk appears higher than that for the agent of classical BSE, which could only be transmitted to mouse lemurs after a first passage in macaques (14). We report oral transmission of the L-BSE agent in young and adult primates. Transmission by the IC route has also been reported in young macaques (6,7). A previous study of L-BSE in transgenic mice expressing human PrP suggested an absence of any transmission barrier between cattle and humans for this particular strain of the agent of BSE, in contrast to findings for the agent of classical BSE (9). 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.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3310119/
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge
Author item Greenlee, Justin item MOORE, S – Orise Fellow item WEST-GREENLEE, M – Iowa State University
Submitted to: Prion
Publication Type: Abstract Only
Publication Acceptance Date: 5/14/2018
Publication Date: 5/22/2018
Citation: Greenlee, J.J., Moore, S.J., West Greenlee, M.H. 2018. The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge. Prion 2018, May 22-25, 2018, Santiago de Compostela, Spain. Paper No. P98, page 116. Interpretive Summary:
Technical Abstract: 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 H-type 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.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=353094
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.
PRION 2018 CONFERENCE ABSTRACT
Snip…see ;
https://bse-atypical.blogspot.com/2021/09/atypical-bovine-spongiform.html
Kind regards, terry