INTRAFAMILIAL TRANSMISSION OF HEPATITIS-C VIRUS

The intrafamilial transmission pattern of hepatitis C virus (HCV) was examined in 118 family members of 61 index patients with type C chroni c liver disease using anti-HCV antibodies and HCV RNA assay. The study subjects consisted of eight parents, 49 spouses, 50 children, eight s iblings and three other relatives. The positivity rates of anti-C100, anti-JCC, second-generation anti-HCV and HCV RNA were 6.8, 12.7, 12.7 and 11.0%, respectively. Positivity in one or more anti-HCV antibody a ssay was detected in 3/24 (12.5%) father-child pairs, 3/17 (17.6%) mot her-child pairs, 2/8 (25%) sibling pairs, 6/38 (15.8%) husband-wife pa irs and 2/13 (15.4%) wife-husband pairs. In spouses, positivity for an ti-HCV antibody or HCV RNA was observed after 40 years of age. None of 11 spouses married < 15 years was positive for any anti-HCV assay or HCV RNA, In spouses whose age was > 50 years and duration of marriage was > 25 years, anti-HCV or HCV RNA was frequently detected (32.0%). H owever, when seven pairs involving four spouses, one mother-daughter p air and two sibling pairs were subtyped, the same HCV subtypes were fo und in only four pairs (type II in three pairs and type III in one pai r). Further, the agreement rate between anti-HCV and HCV RNA was > 90% . These results suggest that intrafamilial transmission of HCV, reveal ed by the subtyping method, is considered lower than the percentage of positivity for anti-HCV antibodies or HCV RNA in family members of pa tients with type C chronic liver disease. Thus, the intrafamilial tran smission of HCV seems to be quite rare and much less common than that of HBV.