Taiwan is a hyperendemic area of hepatitis B virus (HBV) infection where chronic hepatitis B is the most important cause of liver cirrhosis and hepatoma. Since, diagnostic kit for detecting hepatitis C virus (HCV) infection has been developed, HCV was found to be another important etiology of chronic liver disease. In order to study the seroprevalence of HCV infection among preschool children after mass hepatitis B vaccination program in Taiwan, a community-based survey was carried out in 54 kindergartens in 10 urban areas, 10 rural areas, and two aboriginal areas randomly selected through stratified sampling. Serum specimens of 2538 preschool children were screened for the HCV antibodies (anti-HCV) by a commercially available third-generation microparticle enzyme immunoassay and for HBV markers by radioimmunoassay methods. The multivariate-adjusted odd ratios (ORm) with their 95% confidence intervals (CI) were estimated through the multiple logistic regression analysis. A total of 58 children were anti-HCV seropositive, giving a prevalence of 2.3%. The prevalence of anti-HCV was 1.0% (5 of 484) among aboriginal children, a significantly decreased seroprevalence compared with those among other ethnic groups after multivariate adjustment. Boys had a higher anti-HCV seroprevalence, but not statistically significantly different from girls (ORm: 1.6; 95% CI: 0.9-2.8; p = 0.08). The seroprevalence of the age group of 3-4 years was lower than that of the age group of 5-6 years (ORm: 2.2; 95% CI: 1.1-4.2; p = 0.02). After multivariate adjustment, preschool children with natural HBV infection had a higher anti-HCV seroprevalence, but not statistically significantly different from those without natural HBV-infection (ORm: 2.6; 95% CI: 0.9-7.4; p = 0.08 for HBV-infected vs. uninfected). HCV infection varies with gender, residential area, and natural HBV infection. HCV and HBV might share common transmission routes in Taiwan.
