[Prion disease as infectious disease transmissible from animals to human].

Prion diseases such as bovine spongiform encephalopathy (BSE) have been recognized as zoonosis since the existence of variant Creutzfeldt-Jakob disease (vCJD) was reported in 1996. After then, BSE became a serious social problem all over the world. The incidence of BSE in EU and UK appears declining, and the vCJD incidence also shows a tendency to decrease. On the contrary, fears for the spread of BSE became actual problems: BSE occurrence outside of EU, introduction of BSE to other ruminants, and transmission of vCJD by blood transfusion. To prevent further spread of animal prion diseases and to reduce their risk to human being, active surveillance for animal prion diseases, removal of specified risk materials from food and feed chains, and effective feed regulation for livestock should be important. For the disclosure and elimination of prion-contaminated blood, materials for medical and pharmaceutical products, it is required to improve the sensitivity of prion detection methods. Furthermore, establishment of the therapeutics for human prion diseases is urgent problem.