Bovine spongiform encephalopathy (BSE) was first diagnosed in the United Kingdom in 1986, and until the end of 2000 the disease was found in 180,924 cattle. Increasing numbers of BSE cases are now being observed in certain other European countries through 1994 to 2000. In December, 2000 Germany diagnosed its first local BSE cases.

BSE belongs to the transmissible spongiform encephalopathies (TSE) group that can affect humans (Creutzfeldt-Jacob, Gerstmann-Straussler syndrome, kuru and fatal familiar insomnia), sheep (scrapie), mink (mink transmissible encephalopathy), felines, deer and other wild animals. The cause of the disease is a distorted prion that affects the central nervous system being expressed histologically by the presence of vacuolar changes in the neurons and neuropil in specific areas of the brain such as the obex, thus giving a spongiform aspect to the brain tissue.

The origin of BSE may be explained by oral exposure to a scrapie-like agent in the ruminant-derived protein of meat and bone meal included in concentrates or feed supplements. Experimental transmissibility of BSE to cattle has been demonstrated following parenteral and oral challenge with brain tissue from affected cattle. The disease became extremely important because of the link of BSE to a new variant (vCJD) of human Creutzfeldt-Jacob disease (CJD), of which 10 cases were diagnosed in 1996. Until 31 December 2000, a total of 83 confirmed deaths from the disease were reported in the UK. The most likely explanation for the occurrence of vCJD in humans is the exposure of the victims to the etiological agent of BSE believed to be an abnormal form of the prion protein (PrPres).

Israel is one of the few countries that banned the importation of meat and bone meal of ruminant origin from the U.K. in 1988. The Department of Pathology of the Kimron Veterinary Institute is conducting an annual BSE survey according to OIE protocols to monitor the bovine population for specific manifestations of the disease. During 1997-2000, 988 bovine brains were examined; some of the cattle had CNS signs (but none even remotely resembled of BSE) as well from cattle randomly sampled at abattoirs. All were found to be negative.

In 2001 the BSE survey will be extended by introducing the new Prionics Check test. This method was approved by the OIE.

It is possible that in the future, every cow over 30 months old, will be tested for BSE before entering the food chain if such a decision is taken by the veterinary services.