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Institute of Novel and Emerging Infectious Diseases (INNT)

NRL for Bovine Spongiform Encephalopathy (BSE)

The number of notified cases of bovine spongiform encephalopathy (BSE) in cattle has been decreasing for several years. The maximum of the case numbers in the United Kingdom was observed in 1993/1994, while in the remaining EU member states, the peak occurred in 2001/2001. In Germany, the peak was reached in 2001 with 125 notified BSe cases. 2008 and 2009, two cases each were diagnosed. It can therefore be stated that the comprehensive control measures (prohibition of the feeding of animal proteins to mammalians, definition and removal of specified risk materials, profound BSE surveillance) that have been in place since 2001, new infections have been largely prevented. Due to this positive development, it was possible for the 15 ‘old’ EU member states to apply for the increase of the minimal test age of slaughtered and fallen stock bovines to 48 months. By doing so, the number of tested cattle was reduced from 4 million to less that 2 million BSE rapid tests in 2009. The NRL assisted in these analyses by specified support of the laboratories and by the organisation of a yearly ring trial with the 20 state and private laboratories using these tests.

Morover, the NRL assists by preparing reports in the frame of national (according to the national ‘Tierimpfstoffverordnung’) and international approvals of TSE rapid tests (according to regulation (EG) Nr. 999/2001), by official batch controls. The Community Reference Laboratory (CRL) relies more and more on the practical testing to be performed in one defined NRL within the European Union, and informs all NRLs about the outcome of this testing. Therefore, the practical testing at the FLI can be eliminated for many batches and can be reduced to the document control and the report. On the other hand, the FLI has accepted to perform the EU wide testing for two of the rapid tests (BioRad TeSeE and Prionics Check LIA). This means a considerable amount of work, since at the beginning of the process, the acceptable ranges for the values of defined sample sets need to be elaborated. Also, a more extensive testing is necessary for a EU wide batch release. While the preparations have been successfully finished for the BioRad TeSeE test and the first batch has already been released using the EU wide protocol, the preparation for the EU wide batch release of the LIA test is still ongoing.  

Samples that give a reactive results in the rapid test are analysed at the NRL using OIE approved confirmatory methods (see OIE ‚Manual for Diagnostic Tests and Vaccines for Terrestrial Animals). This includes histopathological, immunohistochemical or protein biochemical (OIE SAF-immunoblot) methods. The two latter methods are highly sensitive, but as they are very time intensive, they are not applicable for a mass screening. The reliability of these methods is being supervised by regular ring trials (at least two per method and year) organized by the CRL. As an internal quality standard, the accreditation of the laboratory and the methods according to ISO 17 025 including all regulations for the documentation, the method validation, continuing control and training of the staff and the performance of internal and external audits can be mentioned. The NRL is a member of international research cooperations and its staff regularly joins national and international trainings and meetings and contribute to the training of colleagues from other countries. 

Major consulting service for the German Ministry of Agriculture (BMEL), EFSA and politicians were necessary concerning the given reduction of BSE control measures according to the TSE road map.

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