Prevalence of second generation antibody to hepatitis C virus among voluntary blood donors in Osaka, Japan.

To clarify the demographic characteristics of the prevalence of hepatitis C virus (HCV) infection in Osaka, Japan, where hepatocellular carcinoma is common, we investigated the screening data of antibody to HCV (anti-HCV, DAINABOTHCVPHA, second generation assay) in 197,600 voluntary blood donors residing in Osaka. The study found that age-standardized prevalence of anti-HCV was significantly higher than that of HBsAg (2.25 cf 0.86 percent among males, P < 0.001; 2.17 cf 0.55 percent among females, P < 0.001. It was much higher in the blood donors aged 55-64 years than in those aged 16-54 years (8.49 cf 1.32 percent among males, P < 10(-5); 7.26 cf 1.42 percent among females, P < 10(-5)). The prevalence of anti-HCV among males was significantly higher than that of females in the younger (25-34 years) generations (1.02 to 1.49 percent cf 0.71 to 1.13 percent, P < 0.05). A similar tendency was observed in the prevalence of high-titer (> or = 2(12)) anti-HCV. The number of coinfection (both HBsAg and anti-HCV seropositive) was very small, and it was not statistically different from the expected number.