[Serological investigation on intrafamilial transmission of HCV infection].

To clarify the intrafamilial transmission of HCV infection, the antibody to HCV was assayed in 124 serum samples from the family members of 60 HCV-Ab (+) index cases (group C), and compared with that from 83 family members of 40 HCV-Ab (-) index patients with hepatitis B (group B), Nine of 124, including 2 parents, 6 spouse and 1 granddaughter, were positive for anti-HCV. The prevalence of anti-HCV was 7.3% (9/124) in total, and 1.85% (2/108) in the subjects who had no history of blood donation. None of 83 was positive for anti-HCV in group B. On the other hand, the prevalence of HBV infection was 25.33% in the group of HCV infection only, and 40.91% in the group with HBV/HCV double-infection or HBV infection. It indicates that the risk of HBV intrafamilial transmission is higher than that of HCV, and the risk of transmission of HCV from mother to infant may be lower than that of sexual transmission.