Following the request from the European Commission, scientists at EFSA investigated the origins of isolated cases of BSE in cattle in the EU.
As BSE can be transmitted to cattle through contaminated feed, mainly in the first year, the key measure for controlling the disease in the EU is a ban on the use of animal proteins in livestock feed.
Sixty cases of classical BSE have been reported in cattle born after the EU ban was enforced in 2001. None of these animals entered the food chain. The Commission asked EFSA to determine if these cases were caused by contaminated feed or whether they occurred spontaneously, i.e. without an apparent cause.
Experts from EFSA concluded that contaminated feed is the most likely source of infection. This is because the infectious agent that causes BSE has the ability to remain active for many years. Cattle may have been exposed to contaminated feed because the BSE infectious agent was present where feed was stored or handled. Another possibility is that contaminated feed ingredients may have been imported from non-EU countries. Experts could also not rule out any other causes due to the difficulty of investigating individual cases.
They made a series of recommendations to maintain and strengthen the EU monitoring and reporting system, and to evaluate new scientific data that become available.