The presence of high and low incidence districts of Australia antigen in Miyagi prefecture.

Age distribution of per cent positives of Australia (Au) antigen in several counties of Miyagi Prefecture was compared. Although the average incidence throughout the Prefecture was 1.7%, the highest incidence of 4.5% was found in Kurikoma district and the lowest incidence of 0.3%, in Marumori district. For the explanation of such a difference, no particular geographic and anthropological difference could be found. However, the age distribution of antibody was different between these two districts.