BSE, bovine spongiform encephalopathy caused by prions, was for the first time observed in 1986 in Great Britain. BSE and other spongiform encephalopathles are believed to be caused by prions. Prions mainly or exclusively consist of a cellular protein which has undergone a change in its conformation. BSE was presumably spread by trade in feed containing the infectious agent; meanwhile it has been found in many European countries and overseas with it much bower prevalence, however. There is strong evidence that both a previously unknown human prion disease, a new variant of the Creutzfeldt-Jakob disease (vCJD), and BSE are caused by the same agent, although the mode of its transmission, average incubation period and the molecular mechanisms of prion increase are not sufficiently known. BSE and CJD lead to a spongiform change in the brain, deposition of prion protein aggregates, loss of nerve cells and finally to death after it short period of disease. vCjD is histologically characterized by 'florid' plaques, biochemically by PrP type 2B. It has so far only been found in patients homozygous for methionine at codon 129 of the human prion protein gene, Measures to minimize the spread of BSE in domestic animals and its transmission to humans have been taken in EU Countries. In addition, great efforts are being made in research to get insight into the infectious mechanism, improve diagnostics and develop therapeutic strategies.
