Surveillance and simulation of bovine spongiform encephalopathy and scrapie in small ruminants in Switzerland

Hausermann, C.; Schwermer, H.; Oevermann, Anna; Nentwig, Alice; Zurbriggen, Andreas; Heim, Dagmar; Seuberlich, Torsten (2010). Surveillance and simulation of bovine spongiform encephalopathy and scrapie in small ruminants in Switzerland. BMC veterinary research, 6(1), p. 20. London: BioMed Central 10.1186/1746-6148-6-20

[img]
Preview
Text
1746-6148-6-20.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (1MB) | Preview

BACKGROUND: After bovine spongiform encephalopathy (BSE) emerged in European cattle livestock in 1986 a fundamental question was whether the agent established also in the small ruminants' population. In Switzerland transmissible spongiform encephalopathies (TSEs) in small ruminants have been monitored since 1990. While in the most recent TSE cases a BSE infection could be excluded, for historical cases techniques to discriminate scrapie from BSE had not been available at the time of diagnosis and thus their status remained unclear. We herein applied state-of-the-art techniques to retrospectively classify these animals and to re-analyze the affected flocks for secondary cases. These results were the basis for models, simulating the course of TSEs over a period of 70 years. The aim was to come to a statistically based overall assessment of the TSE situation in the domestic small ruminant population in Switzerland. RESULTS: In sum 16 TSE cases were identified in small ruminants in Switzerland since 1981, of which eight were atypical and six were classical scrapie. In two animals retrospective analysis did not allow any further classification due to the lack of appropriate tissue samples. We found no evidence for an infection with the BSE agent in the cases under investigation. In none of the affected flocks, secondary cases were identified. A Bayesian prevalence calculation resulted in most likely estimates of one case of BSE, five cases of classical scrapie and 21 cases of atypical scrapie per 100'000 small ruminants. According to our models none of the TSEs is considered to cause a broader epidemic in Switzerland. In a closed population, they are rather expected to fade out in the next decades or, in case of a sporadic origin, may remain at a very low level. CONCLUSIONS: In summary, these data indicate that despite a significant epidemic of BSE in cattle, there is no evidence that BSE established in the small ruminant population in Switzerland. Classical and atypical scrapie both occur at a very low level and are not expected to escalate into an epidemic. In this situation the extent of TSE surveillance in small ruminants requires reevaluation based on cost-benefit analysis.

Item Type:

Journal Article (Original Article)

Division/Institute:

05 Veterinary Medicine > Department of Clinical Veterinary Medicine (DKV)
05 Veterinary Medicine > Department of Clinical Veterinary Medicine (DKV) > Small Animal Clinic > Small Animal Clinic, Internal Medicine
05 Veterinary Medicine > Department of Clinical Veterinary Medicine (DKV) > Small Animal Clinic
05 Veterinary Medicine > Department of Clinical Research and Veterinary Public Health (DCR-VPH) > Experimental Clinical Research
05 Veterinary Medicine > Other Institutions > Teaching Staff, Vetsuisse Faculty
05 Veterinary Medicine > Department of Clinical Research and Veterinary Public Health (DCR-VPH)

UniBE Contributor:

Oevermann, Anna; Nentwig, Alice; Zurbriggen, Andreas; Heim, Dagmar and Seuberlich, Torsten

Subjects:

600 Technology > 630 Agriculture

ISSN:

1746-6148

Publisher:

BioMed Central

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 14:32

Last Modified:

08 Jun 2016 10:29

Publisher DOI:

10.1186/1746-6148-6-20

Web of Science ID:

000277613100001

BORIS DOI:

10.7892/boris.12365

URI:

https://boris.unibe.ch/id/eprint/12365 (FactScience: 218697)

Actions (login required)

Edit item Edit item
Provide Feedback