Abstract
The clinical symptoms of epidemic hepatitis at the Onoda, and Toyoda districts of Kumayama-cho, Akayuwa-gun in Okayama prefecture were mostly the typical form and violent form until February 1953 from the beginning of the prevalence in 1952, and the symptoms became gradually mild until the end of 1954 from the spring of 1953 at which time the prevalence became prolonged and the increase of the abortive form and mild form was observed. And it was certified that the prolongation of the prevalence brought remarkable changes on the clinical picture.
