EFSA Scientific Report on the evaluation of rapid post mortem TSE tests intended for small ruminants 2nd
Question nº: EFSA-Q-2003-084
Summary
The European Food Safety Authority (EFSA) and its Scientific Expert Working Group on Transmissible Spongiform Encephalopathy (TSE) Testing were asked by the European Commission (EC) to take over the mandate of the former Scientific Steering Committee (SSC) for the scientific evaluation of rapid TSE/BSE (Bovine Spongiform Encephalopathy) tests.
Until 2004 no evaluation of rapid TSE tests on material from small ruminants had been conducted by the European Commission. In the absence of such data, 5 rapid post mortem TSE tests which performed satisfactorily on bovine tissue were provisionally approved by the EC for the TSE monitoring of small ruminants, in accordance with the TSE Regulation (EC) No 999/2001. Following an EC call for expression of interest in the Official Journal of the European Union (No C15) on 22 January 2003, several parties indicated their interest in participating in this third European evaluation exercise for newly developed rapid post mortem and live animal TSE/BSE tests.
EFSA was asked to take over the scientific aspects of this evaluation and to assess the outcome of the European Commission’s Institute of Reference Materials and Measurements (IRMM) evaluation of rapid TSE post mortem tests, taking also into account an opinion of the French Food Safety Agency (AFSSA), and to give recommendations on the approval of the tests.
During January to June 2004, IRMM carried out an evaluation of the diagnostic and analytical sensitivities, of the diagnostic specificity and repeatability of six rapid post mortem tests on samples from natural scrapie cases. Additionally the ability of these tests and their analytical sensitivity for the detection of “atypical” scrapie strain (Nor98) in sheep tissue were evaluated. During August 2004, further brain samples from three clinical cases of sheep orally challenged with BSE-affected cattle brain homogenate were screened using each of the six rapid tests. In March 2005, in response to concerns of the EFSA WG on TSE Testing following confirmation of a case of BSE in a French goat, the six rapid tests were also evaluated against dilutions of brain homogenates from experimentally BSE infected sheep to provide analytical sensitivity for this material comparable to that previously obtained for scrapie.
On 17 May 2005, the EFSA TSE Testing WG adopted its Scientific Report on the Evaluation of Rapid post mortem TSE Tests intended for Small Ruminants (EFSA, 2005) on six post mortem tests.
In July 2005, EFSA has received IRMM’s reports on the laboratory evaluation of three additional post mortem TSE tests intended for small ruminants. The assessment consists of the application dossiers, on results of the laboratory evaluation and of the package inserts of the three tests.
Based on an overall assessment on the application dossiers, the laboratory evaluation and the approval of the package inserts, the experts of EFSA´s Working Group on TSE Testing recommends two tests (IDEXX Herdchek, InPro CDI-5) for approval by the European Commission to be used in the field to assess the prevalence of classical scrapie and BSE in brainstem samples of sheep. Both tests are also recommended for the detection of “atypical” scrapie (Nor98) using cerebrum or cerebellum samples. In addition the IDEXX Herdchek test can be recommended also for brainstem samples to detect “atypical” scrapie (Nor98).
The Fuijrebio FRELISA post mortem Test, (Fujirebio Inc.) is not recommended for approval on small ruminant tissue.
In respect to goats the EFSA Working Group on TSE Testing recommended on the basis of current limited scientific knowledge that, in terms of testing, this species should be equally treated as sheep.
Dernière mise à jour: 29/09/2005
