[Transmissible spongiform encephalopathies--illnesses in the human].

Transmissible spongiform encephalopathies (TSEs) or prion diseases in man and animals are of utmost interest at present. Reasons are the highly probable origin from BSE of a new variant of Creutzfeldt-Jakob disease (CJD) in the UK and France, the new paradigm in biomedicine of the association of heredity and transmissibility, and the possible propagation of infectivity by protein only according to the prion hypothesis. Determination of the 14-3-3 protein in CSF and magnetic resonance imaging are promising new diagnostic tools; however, clinical examination yields only a suspect diagnosis, with formal criteria for "probable" or "possible" CJD. Definite diagnosis relies on neuropathology at autopsy or, in rare instances, brain biopsy. Handling of laboratory material from TSE patients requires specific measures of precaution and decontamination. Although blood and blood products have been shown to transmit disease, experimental and epidemiologic data for disease transmission via blood transfusion are lacking. New WHO regulations define exclusion criteria for blood donors. A special situation applies to the UK because the distribution of infectivity in the new CJD variant might differ from that of classical TSEs; therefore leukodepletion of blood donations was recommended.