Switzerland Bovine Spongiform Encephalopathy Atypical L-Type
Switzerland - Bovine spongiform encephalopathy - Immediate notification
GENERAL INFORMATION
COUNTRY/TERRITORY OR ZONE
COUNTRY/TERRITORY
ANIMAL TYPE
TERRESTRIAL
DISEASE CATEGORY
OIE-listed
EVENT ID
4962
DISEASE
Bovine spongiform encephalopathy
CAUSAL AGENT
Bovine spongiform encephalopathy prion, atypical strain, L-type
GENOTYPE / SEROTYPE / SUBTYPE
-
START DATE
2023/03/03
REASON FOR NOTIFICATION
Recurrence of an eradicated disease
DATE OF LAST OCCURRENCE
2020/02/03
CONFIRMATION DATE
2023/03/08
EVENT STATUS
On-going
END DATE
-
SELF-DECLARATION
NO
REPORT INFORMATION
REPORT NUMBER
Immediate notification
REPORT ID
IN_159813
REPORT REFERENCE
BSE_2023_GR
REPORT DATE
2023/03/13
REPORT STATUS
Validated
NO EVOLUTION REPORT
-
EPIDEMIOLOGY
SOURCE OF EVENT OR ORIGIN OF INFECTION
Unknown or inconclusive
EPIDEMIOLOGICAL COMMENTS
The 12-year-old cow from a holding in the Canton of Grisons has been sampled at slaughter in the framework of the BSE surveillance program on 27 February 2023. The brain stem material was tested positive by IDEXX HerdChek BSE-Scrapie Ag Test on 03 March 2023. The result was confirmed on 08 March 2023 by Western lmmunoblot at the National Reference Laboratory for Transmissible Spongiform Encephalopathies (Neurocenter, Vetsuisse Faculty, Berne, Switzerland). The pathological prion protein was classified as (L) -Type, therefore the case has been categorized as atypical BSE. The entire carcass was disposed of as category 1 material.
QUANTITATIVE DATA SUMMARY
MEASURING UNIT
Animal
SpeciesSusceptibleCasesDeathsKilled and Disposed ofSlaughtered/ Killed for commercial useVaccinated
Cattle (DOMESTIC)NEW1910010TOTAL1910010
DIAGNOSTIC DETAILS
CLINICAL SIGNS
NO
METHOD OF DIAGNOSTIC
Diagnostic test
Test name Laboratory Species sampled Outbreaks Result date Result
Antigen detection Western blot (Ag Western blot) NeuroCenter, Department of Clinical Research and Veterinary Public Health (DCR-VPH), Division of Experimental Clinical Research, University of Bern Cattle Prättigau-Davos 2023/03/08 Positive
CONTROL MEASURES AT EVENT LEVEL
CONTROL MEASURES AT EVENT LEVEL
DOMESTIC ANIMALS
WILD ANIMALS
Traceability
Applied
Selective killing and disposal
Applied
Official disposal of carcasses, by-products and waste
Applied
Disinfection
Applied
Official destruction of animal products
Applied
Ante and post-mortem inspections
To be applied
https://wahis.woah.org/#/in-review/4962
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OIE Conclusions on transmissibility of atypical BSE among cattle
Given that cattle have been successfully infected by the oral route, at least for L-BSE, it is reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle are exposed to contaminated feed. In addition, based on reports of atypical BSE from several countries that have not had C-BSE, it appears likely that atypical BSE would arise as a spontaneous disease in any country, albeit at a very low incidence in old cattle. In the presence of livestock industry practices that would allow it to be recycled in the cattle feed chain, it is likely that some level of exposure and transmission may occur. As a result, since atypical BSE can be reasonably considered to pose a potential background level of risk for any country with cattle, the recycling of both classical and atypical strains in the cattle and broader ruminant populations should be avoided.
https://www.oie.int/fileadmin/SST/a...alopathy/AN/A_AhG_BSEsurv_RiskAss_Mar2019.pdf
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
snip...
REFERENCES
SNIP...END SEE FULL TEXT;
http://web.oie.int/downld/PROC2020/A_SCAD_Sept2019.pdf
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/
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/
''H-TYPE BSE AGENT IS TRANSMISSIBLE BY THE ORONASAL ROUTE''
This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=353094
terry
Switzerland - Bovine spongiform encephalopathy - Immediate notification
GENERAL INFORMATION
COUNTRY/TERRITORY OR ZONE
COUNTRY/TERRITORY
ANIMAL TYPE
TERRESTRIAL
DISEASE CATEGORY
OIE-listed
EVENT ID
4962
DISEASE
Bovine spongiform encephalopathy
CAUSAL AGENT
Bovine spongiform encephalopathy prion, atypical strain, L-type
GENOTYPE / SEROTYPE / SUBTYPE
-
START DATE
2023/03/03
REASON FOR NOTIFICATION
Recurrence of an eradicated disease
DATE OF LAST OCCURRENCE
2020/02/03
CONFIRMATION DATE
2023/03/08
EVENT STATUS
On-going
END DATE
-
SELF-DECLARATION
NO
REPORT INFORMATION
REPORT NUMBER
Immediate notification
REPORT ID
IN_159813
REPORT REFERENCE
BSE_2023_GR
REPORT DATE
2023/03/13
REPORT STATUS
Validated
NO EVOLUTION REPORT
-
EPIDEMIOLOGY
SOURCE OF EVENT OR ORIGIN OF INFECTION
Unknown or inconclusive
EPIDEMIOLOGICAL COMMENTS
The 12-year-old cow from a holding in the Canton of Grisons has been sampled at slaughter in the framework of the BSE surveillance program on 27 February 2023. The brain stem material was tested positive by IDEXX HerdChek BSE-Scrapie Ag Test on 03 March 2023. The result was confirmed on 08 March 2023 by Western lmmunoblot at the National Reference Laboratory for Transmissible Spongiform Encephalopathies (Neurocenter, Vetsuisse Faculty, Berne, Switzerland). The pathological prion protein was classified as (L) -Type, therefore the case has been categorized as atypical BSE. The entire carcass was disposed of as category 1 material.
QUANTITATIVE DATA SUMMARY
MEASURING UNIT
Animal
SpeciesSusceptibleCasesDeathsKilled and Disposed ofSlaughtered/ Killed for commercial useVaccinated
Cattle (DOMESTIC)NEW1910010TOTAL1910010
DIAGNOSTIC DETAILS
CLINICAL SIGNS
NO
METHOD OF DIAGNOSTIC
Diagnostic test
Test name Laboratory Species sampled Outbreaks Result date Result
Antigen detection Western blot (Ag Western blot) NeuroCenter, Department of Clinical Research and Veterinary Public Health (DCR-VPH), Division of Experimental Clinical Research, University of Bern Cattle Prättigau-Davos 2023/03/08 Positive
CONTROL MEASURES AT EVENT LEVEL
CONTROL MEASURES AT EVENT LEVEL
DOMESTIC ANIMALS
WILD ANIMALS
Traceability
Applied
Selective killing and disposal
Applied
Official disposal of carcasses, by-products and waste
Applied
Disinfection
Applied
Official destruction of animal products
Applied
Ante and post-mortem inspections
To be applied
https://wahis.woah.org/#/in-review/4962
|
OIE Conclusions on transmissibility of atypical BSE among cattle
Given that cattle have been successfully infected by the oral route, at least for L-BSE, it is reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle are exposed to contaminated feed. In addition, based on reports of atypical BSE from several countries that have not had C-BSE, it appears likely that atypical BSE would arise as a spontaneous disease in any country, albeit at a very low incidence in old cattle. In the presence of livestock industry practices that would allow it to be recycled in the cattle feed chain, it is likely that some level of exposure and transmission may occur. As a result, since atypical BSE can be reasonably considered to pose a potential background level of risk for any country with cattle, the recycling of both classical and atypical strains in the cattle and broader ruminant populations should be avoided.
https://www.oie.int/fileadmin/SST/a...alopathy/AN/A_AhG_BSEsurv_RiskAss_Mar2019.pdf
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
snip...
REFERENCES
SNIP...END SEE FULL TEXT;
http://web.oie.int/downld/PROC2020/A_SCAD_Sept2019.pdf
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/
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/
''H-TYPE BSE AGENT IS TRANSMISSIBLE BY THE ORONASAL ROUTE''
This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=353094
terry
