I NFECTIOUS viral hepatitis (VH) is widespread, especially in the tropics and subtropics. The natural history of the disease ranges from mild infections without clinical manifestations to acute infections with icterus and other hepatic dysfunctions. Several investigators1-3 have reported that anicteric VH is a subclinical infection characterized by milder symptoms and a shorter duration of illness; however Bloomfield 4 was one of the first to recognize that anicteric VH can result in chronic liver disease and that ascites, hepatic failure, or esophageal varices may cause the first clinical awareness.
There are seasonal variations in the incidence of VH, the incidence tending to increase in the fall and early winter.5 A major cyclic pattern with a seven-year interval 6 exists in the United States. Present studies of clinical manifestations and of histologic variation in liver morphology have been conducted since 1959 in the First Naval District of Taiwan and