[Epidemiologic aspects of scrapie and BSE including an analysis of risk factors]

After a discussion of the different hypotheses about the causative agent of prion diseases, various aspects of the two most important animal prion diseases, i.e. BSE and scrapie are described. This thesis focuses on the search for a preclinical diagnosis. A major breakthrough was the discovery of a new technique for detecting the disease-associated protein in tonsillar biopsies from scrapie-infected sheep long before clinical signs appeared. Another essential part of the studies described in this thesis concerned a risk analysis for BSE in a country like the Netherlands. Major risk factors were assessed, including an assessment of the efficacy of Dutch rendering procedures in the inactivation of the agents of scrapie and BSE.