Descriptive Epidemiology of Prion Disease in Japan: 1999–2012

BACKGROUND: Epidemiologic features of prion diseases in Japan, in particular morbidity and mortality, have not been clarified. METHODS: Since 1999, the Research Committee has been conducting surveillance of prion diseases, and the surveillance data were used to assess incident cases of prion diseases. For the observation of fatal cases, vital statistics were used. RESULTS: Both incidence and mortality rates of prion diseases increased during the 2000s in Japan. However, this increase was observed only in relatively old age groups. CONCLUSIONS: The increased number of patients among old age groups might be due to increased recognition of the diseases. If so, the number of cases should plateau in the near future.