The development of rapid tests to diagnose BSE has been a top priority since mandatory active surveillance programs were introduced in the European Union. So far the European Commission (EC) has approved twelve rapid tests for BSE monitoring in cattle.

By the middle of 2004 more than 33 million rapid tests had been performed in Europe within the mandatory rapid testing of all slaughtered cattle above the age of 30 months. Currently, the Prionics^®-Check tests are the most widely used BSE-tests in the world. In Europe about 10 million BSE tests are performed annually, and in Japan roughly 1 million. A total of 12 rapid tests based on different detection principles are approved for BSE monitoring in cattle in Europe: 1 Western blot, 10 ELISA, and 1 Strip-based test. All are post mortem tests that use brain or spinal cord tissue of the slaughtered animal.

New generation of rapid BSE tests
While Western blot-based BSE tests have been shown to be the most reliable and accurate rapid BSE tests by delivering a fingerprint of the prion protein (giving neither false positive results nor initial reactive results), ELISA tests are widely used because they can be automated for high throughput screening. However, future BSE testing requirements might be met with a new generation of rapid BSE tests based on an immunochromatographic principle. The strips are simply dipped in the homogenized and digested brain and the prion proteins present in the sample run up the strips by lateral flow, until they are captured by an antibody. While two such tests have passed the EC laboratory evaluation in 2004, only one of them - the Prionics^®-Check PrioSTRIP - has successfully completed the field trial. This rapid test combines high testing speed (100 minutes from brain to result) with simple handling and at the same time delivers results with 100% sensitivity and specificity.