A sporadic and rare, but fatal human disease that usually strikes people over 65. It occurs worldwide at an estimated annual rate of one case per million population. About 10-15% of CJD cases are inherited. A small number of cases occurred as the result of various medical treatments or procedures which inadvertently transferred the CJD agent. In March 1996, the British government announced a possible link between bovine spongiform encephalopathy (BSE) and CJD. The announcement was prompted by the discovery of several atypical cases of CJD in Great Britain.