This study evaluated the roles of multiple factors in hepatitis C virus (HCV) infection, with emphasis on the modification of various individual characteristics on the risk associated with percutaneous exposure to blood. Serum samples taken from 4869 men in Taiwan within a cohort study were tested for HCV antibody. The overall positive rate of anti-HCV was 1n6%. In a logistic regression, factors positively associated with anti-HCV positivity were previous blood transfusion (odds ratio [OR] l

more »

... 8 ; 95 % confidence interval [CI] l 4n26-12n45), a history of surgery (OR l 2n06 ; 95 % CI l 1n23-3n46), and lower educational levels (OR l 1n94 ; 95 % CI l 1n14-3n32). The anti-HCV positive rate was significantly lower in hepatitis B surface antigen (HBsAg) carriers than in non-carriers (OR l 0n60 ; 95 % CI l 0n37-0n95). Ageing, lower educational levels, O blood group, and Taiwanese ethnicity enhanced the likelihood of HCV infection through blood transfusion\surgery, whereas HBsAg status, cigarette smoking, and habitual alcohol drinking reduced it.