Evaluation of the application of Denmark to be recognised as having a negligible risk of classical scrapie

scrapie, negligible, risk, classical, Denmark, surveillance
First published in the EFSA Journal
19 novembre 2015
Approved
28 ottobre 2015
Type
Scientific Report of EFSA

Abstract

Denmark submitted a request to the European Commission to be recognised as a Member State with negligible risk of classical scrapie. EFSA has been asked to assess if Denmark in its application has demonstrated for a period of at least seven years proposed/in the future, that a sufficient number of ovine and caprine animals over 18 months of age, representative of slaughtered, culled or found dead on farm animals, have been tested annually, to provide a 95% level of confidence of detecting classical scrapie if it is present in that population at a prevalence rate exceeding 0.1%. A risk-based approach using scenario tree modelling with stochastic simulations was applied. There is lack of data on the actual performance of the approved tests in field conditions, especially in sheep. Alternative scenarios were explored extending the range from the sensitivity provided by the past European Union evaluations of screening diagnostic tests to a sensitivity of 50%, consistent with published data obtained under field conditions in infected goat populations. Using data provided by Denmark in its application, the estimated parameters of the scenario tree model and the range of values of sensitivity, it is concluded that Denmark has not tested annually a sufficient number of small ruminants to meet the requirement. Based on the expected number of samples to be tested in 2015 and future years, Denmark would not test a sufficient number of animals to meet the requirement. It is recommended that specific analytical approaches should be agreed upon for use by other Member States when preparing their applications for the recognition of the negligible risk of classical scrapie, and that data on the sensitivity of screening diagnostic tests in field conditions should be generated where possible. 

Panel members at the time of adoption

Ana Allende, Declan Bolton, Marianne Chemaly, Robert Davies, Pablo Salvador Fernández Escámez, Rosina Gironés, Lieve Herman, Kostas Koutsoumanis, Roland Lindqvist, Birgit Nørrung, Antonia Ricci, Lucy Robertson, Giuseppe Ru, Moez Sanaa, Marion Simmons, Panagiotis Skandamis, Emma Snary, Niko Speybroeck, Benno Ter Kuile, John Threlfall, and Helene Wahlström.
European Food Safety Authority
Contact
biohaz [at] efsa.europa.eu
doi
10.2903/j.efsa.2015.4294
EFSA Journal 2015;13(11):4294
Question Number
On request from
European Commission