Beef and bovine spongiform encephalopathy: the risk persists.

Bovine spongiform encephalopathy (BSE) is one of the transmissible spongiform encephalopathies (TSE) that are currently known to the authors to affect only mammals, including man. The diseases are progressive, fatal paralyses and dementias, for which there are no methods of certain diagnosis and no treatment. In this review the disease in cattle, the mode of transfer of these TSEs between animals by mouth, the possible presence of infective agents in the food that we eat, the resistance of BSE to cooking, and the likelihood that humans may become infected are discussed. The origins of BSE, whether from sheep, from cows, or as a mutation are considered. Whatever the origin of BSE, a substantial danger for man exists. Creutzfeld-Jakob disease (CJD), a TSE of man, may have been derived from eating infected animal tissue in the past. The possibility that this was of bovine origin and the implications that this would have for BSE infected meat in human food are discussed.