Rise in the incidence of viral hepatitis in Israel despite improved socioeconomic conditions.

The incidence of viral hepatitis (mostly type A) in Israel, an area highly endemic for the disease, was examined between 1951 and 1985. During a period of improved standards of living, the overall reported incidence of the disease increased. In the Jewish population, the age of peak incidence shifted from 1-4 y to 5-9 y; this change is compatible with improved sanitation. However, whereas the absolute incidence declined among children 1-4 y old, it doubled among those 5-9 y old over the same period. The peak incidence in the non-Jewish population remains in children 1-4 y old. One possible explanation for the rise in overall incidence is an increase in the ratio of clinical to subclinical infections due to a shift of peak incidence to an older age group. Seasonal patterns have persisted against a background of changing morbidity, with the maximal incidence from late summer to midwinter. An unexplained, consistent excess incidence among males is observed for all age groups.