[Unconventional disease agents--a danger for humans and animals?].

The occurrence of bovine spongiform encephalopathy (BSE) in Great Britain in 1985/86, has focused again the public concern as well as scientific interest to the Scrapie disease of sheep and goat known more than 150 years. The agents of scrapie and BSE are characterized by unusual biological and physical-chemical properties, especially their high tenacity. Therefore, they are also designated "unconventional agents of viruses". Different theories have been proposed about their infectious characteristics--especially because of the apparent or real missing of an agent-specific nucleic acid--which are named Virinos, Prions or Nemavirus. The broad host range of Scrapie respective BSE, which includes domestic and wild ruminants, Suidae, Felidae, Mustelidae, small rodents, birds and non-primates, has created some concern since there might be an aetiological correlation between the transmissible spongiform encephalopathies of man (Creutzfeld-Jakob- and Gerstmann-Sträussler-Scheinker-Disease) and that of animals. Although at present neither epidemiological nor molecular biological evidence whatsoever was proved, the hypothesis cannot be completely disproved. The probability of infection through digestive tract seems to be rather unlikely but special precautions should be taken as far as production, investigation and application of human medicine drugs of animal origin. Furthermore, research about the aetiology of "unconventional agents" and pathogenesis of resulting diseases is necessary and should be intensified in Germany. Finally, only an early intra vitam-Diagnose and in vitro detection can avoid an further spread of this new category of diseases.