1984 Volume 25 Issue 11 Pages 1377-1384
Six hundreds and thirty two patients of epidemic hepatitis A broken out in Aomori Prefecture from January to April, 1983 were studied. This was the largest outbreak of Hepatitis A diagnosed by determination of IgM-HA antibody in the world. The male to female ratio of patients was 1:7. Although the age distribution was from 0 to 74 years old, 75% of patients were between 20 to 39. Five male fulminant hepatitis were found and three of them were fatal.
Seventy five percent of patients had eaten raw oyster before onset and it was significantly higher than healthy people in the same period. Oyster farmed in Mutsu Bay was suspected as the infectious vehicle. The prevalence of positive HA antibody investigated in healthy people in Aomori Prefecture was similar to those reported in Japan.
