1995 年 5 巻 2 号 p. 75-80
We conducted an epidemiological study on prevalence of antibodies to hepatitis C virus (anti-HCV) among Japanese workers with a history of blood transfusion and on risks of blood transfusion for anti-HCV positivity. Of 3, 693 workers, 241 (76 males and 165 females) had a history of blood transfusion. For each of these 241 cases, a control, matched for area of residence, sex and age, was selected from those workers who never had blood transfusion. Data on these 482 workers were analyzed. Prevalence of anti-HCV was 12.4% among subjects with a history of blood transfusion and 3.7% among those without (p<0.001). Among subjects with a history of blood transfusion, prevalence of anti-HCV rose with age and was higher in males (19.7%) than in females (9.1%) (p< 0.05). Before 1970, most transfused blood was supplied by commercial donors, and prevalence of anti-HCV was much higher among subjects who received blood transfusion before 1970 than among those who received blood transfusion after 1970. A logistic regression analysis was conducted. Adjusted relative risks for anti-HCV positivity were 3.70 (95% confidence interval : 1.71-8.00) for blood transfusion (p<0.001), 1.98 (1.01-3.87) for age (age, *50 vs age 20-49) (p<0.05), and 1.51 (0.75-3.01) for sex. J Epidemiol, 1995; 5 : 75-80.