[Transmission of spongiform encephalopathies (prion diseases)].

The transmissible spongiform encephalopathies (TSE), or prion diseases, constitute a form of degenerative disorders of the central nervous system, which are characterized by a typical spongiform histological pattern and a fatal course. According to Prusiner's theory, its agent consists of a protein without any nucleic acid, the "proteinaceous infectious agent", or prion. This is a pathologically folded form of the normal prion protein (PrPC), and then called PrPSc. TSE are observed in different mammals including humans. In humans, they include Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), fatal familial insomnia (FFI), Kuru and the new variant of the Creutzfeldt-Jakob disease (vCJD). The longest known TSE is scrapie in sheep. Since 1984 the bovine spongiform encephalopathy (BSE) and since 1996 the variant Creutzfeldt-Jakob disease have been documented. This paper gives an overview on the pathogenesis, epidemiology and the clinical features of the different prion diseases.