Population-based study of hepatitis C virus infection and hepatocellular carcinoma in western Japan

Hepatitis C virus (HCV) infection is a major health problem in Japan. This infection is highly prevalent in subjects with chronic liver disease and is strongly associated with hepatocellular carcinoma. Epidemiological studies conducted by the Japanese Ministry of Health and Welfare showed that the mortality rate associated with hepatocellular carcinoma (HCC) was high in several prefectures in western Japan. In 1990, Saga Prefecture on the island of Kyushu in western Japan reported the highest HCC related mortality rate. Here, we report the results of a population-based survey in Saga Prefecture, where prevalence of HCV infection and mortality rate of HCC was assessed in the general population. From 1992 to 1997, the prevalence of HCV infection was assessed in the general population of 47 districts in Saga Prefecture. Among the 161307 subjects (52590 men, 108357 women, older than 30 years) examined, 13129 (8.1%) reacted positively to HCV antibody (anti-HCV). The prevalence of HCV-Ab reactivity was highest in subjects over 60 years of age. Reactivity increased from 3.6% in subjects 30-49 years old to 11% in those >50 years old. Highly significant differences were observed among the 45 districts in seropositive rates for anti-HCV, with the range being from 0.8 to 20.0%. We evaluated the association between the prevalence of anti-HCV reactivity and age-adjusted death rate from HCC in the general population of these districts, and detected a significant association (Pearson' s correlation coefficient=0.721, P<0.0001, Y=1.86X+16.1). In conclusion, these observations indicated that the outbreak of HCV in this area was a major cause of HCC in the population.