Abstract
The transmissible spongiform encephalopathies are caused by infectious agents but usually present as genetic or sporadic disorders. The nature of the infectious agents is not known. In 1986 a new transmissible spongiform encephalopathy, which was called bovine spongiform encephalopathy or “mad cow disease,” was described in Britain.1 In 1996 the British noted cases of Creutzfeldt–Jakob disease that differed from other cases of the same disease and named this entity new variant Creutzfeldt–Jakob disease.2 The possible association of new variant Creutzfeldt–Jakob disease with bovine spongiform encephalopathy brought these rare diseases to public and political attention. This review summarizes the background information . . .