Prevalence of antibodies to hepatitis C virus among family members of patients with chronic hepatitis C.

In this study, 108 family members of 40 chronically HCV-infected patients (19 post-transfusion and 21 sporadic), and 45 families of 16 anti-HCV-negative index cases (control group) were tested for anti-HCV antibodies. Anti-HCV antibodies were found in 16 (14.8%) families of anti-HCV-positive index cases (15% males and 14.6% females; p = NS), with no difference between families of index cases with post-transfusion and those with sporadic HCV infection. Out of the 16 anti-HCV positive family members, 12 (75%) had clinical and/or serological evidence of chronic liver damage. None of the control group subjects were anti-HCV-positive (p < 0.01). The rate of anti-HCV positivity was 34.4% among spouses, 14.3% among siblings, 16.7% among cohabitants and 2.3% among children; anti-HCV antibodies were not detected among parents. We found a positive correlation between the prevalence of anti-HCV antibodies among families and the severity of the HCV-related chronic liver damage of the index cases (p < 0.00005). In addition, to confirm that HCV infection and HCV-related chronic hepatitis may be transmitted intrafamiliarly, our findings also indicate that horizontal, especially sexual contact, is a more important route of HCV infection than vertical/perinatal transmission. Finally, the risk of acquiring HCV infection among families appears to be the highest when index cases are suffering from severe HCV-related chronic hepatitis.