A RETROSPECTIVE STUDY OF HEPATITIS-C VIRUS CARRIERS IN A LOCAL ENDEMIC TOWN IN JAPAN - A POSSIBLE PRESENCE OF ASYMPTOMATIC CARRIER

Chronic hepatitis, cirrhosis, and hepatocellular carcinoma are the acc epted sequelae of chronic hepatitis C virus (HCV) infection. However, the real natural history of HCV infection is not still well understood . To approach this problem, we investigated 91 individuals positive fo r antibodies against HCV (anti-HCV), who have received annual liver fu nction examination in a local town known to have had high carrier rate s of hepatitis B virus (HBV) and HCV. Among the 91 anti-HCV-positive i ndividuals, 63 had undertaken the annual examination more than five ti mes in the past 14 years. We analyzed retrospectively the past liver f unction test results of these 63 subjects and evaluated their present virological status by determining HCV genotypes and estimating quantit y of HCV RNA in the sera. Among the 63 subjects, 50 (79.4%) had HCV RN A in the serum and 40 (80%) of the 50 subjects with HCV RNA had abnorm al alanine aminotransferase or aspartate aminotransferase level more t han once in their records. However, the other 10 (20%) had no abnormal levels during the period examined. Six of 50 (12%) had ultrasonograph ic findings suggestive of cirrhosis. Thus, HCV-infected individuals in this area did not seem to have progressive liver diseases. Considerin g the advanced ages of the individuals examined (mean 64 years old), w e may have observed a stage in the natural history of HCV infection in which viremia persists in most individuals and the tendency to progre ss to serious chronic liver disease is mild.