Scientific Opinion on the scrapie situation in the EU after 10 years of monitoring and control in sheep and goats

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Article
Panel on Biological Hazards
EFSA Journal
EFSA Journal 2014;12(7):3781 [155 pp.].
doi
10.2903/j.efsa.2014.3781
Panel members at the time of adoption
Olivier Andreoletti, Dorte Lau Baggesen, Declan Bolton, Patrick Butaye, Paul Cook, Robert Davies, Pablo S. Fernandez Escamez, John Griffin, Tine Hald, Arie Havelaar, Kostas Koutsoumanis, Roland Lindqvist, James McLauchlin, Truls Nesbakken, Miguel Prieto Maradona, Antonia Ricci, Giuseppe Ru, Moez Sanaa, Marion Simmons, John Sofos and John Threlfall.
Acknowledgements

The Panel wishes to thank the members of the Working Group on Scrapie situation in the EU: Pier Luigi Acutis, Olivier Andreoletti, Antonello Carta, Christian Ducrot, Jean-Michel Elsen, Thomas Hagenaars, Angel Ortiz-Pelaez, Giuseppe Ru and Marion Simmons for the preparatory work on this scientific opinion and EFSA staff members: Pietro Stella and Luis Vivas-Alegre for the support provided to this scientific opinion.

Type
Opinion of the Scientific Committee/Scientific Panel
On request from
European Commission
Question Number
EFSA-Q-2012-00646
Adopted
10 July 2014
Published in the EFSA Journal
30 July 2014
Last Updated
10 September 2014. This version replaces the previous one/s.
Affiliation
European Food Safety Authority (EFSA), Parma, Italy
Note
Abstract

To assess the effectiveness of the strategies implemented in the European Union (EU) to control Classical scrapie (CS), epidemiological data have been compared in the context of the efforts in terms of control measures applied over time. Official EU surveillance data and results from questionnaire surveys of EU Member States (MSs) have been used along with case studies. A spatio-temporal description of the occurrence of small ruminants TSEs in MSs in the period 2002-2012 is provided, with a particular focus on CS in sheep. Based on information collected from MSs, the potential effectiveness of breeding programmes for resistance to CS (BP-CS) in the dissemination of resistance into the general sheep population has been assessed for those countries for which the CS trend analysis has been performed. CS in sheep was reported in 17 MSs (average prevalence: 8.7 cases/10 000 tests), with heterogeneous trends and geographical distribution: among the 13 countries reporting a consistent number of cases, the trend analysis shows a statistically significant decreasing trend only for six of them. Variations in the implementation of genetic and non-genetic measures for the control of CS may explain the failure to improve the disease situation in the remaining seven MSs. At a national level, a reduction in CS seems to be linked to better-achieving BP-CSs. Control options applied to CS in sheep and goats indicate that a CS eradication policy that relies solely on the detection of infected flocks by post-mortem testing and subsequent depopulation would be unlikely to succeed. A minimum frequency of the ARR allele in a sheep population above which CS may be expected to fade-out could be estimated for each specific national sheep population. Recommendations for additional/alternative measures to control CS in sheep and goats are formulated.

Keywords
Atypical scrapie, breeding programme, Classical scrapie, goat, sheep, surveillance
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Number of Pages
155