Intrafamilial spread of hepatitis C virus infection.

We assessed the prevalence of antibodies to hepatitis C virus (anti-HCV) among 401 household contacts of 161 persons with chronic hepatitis C (index patients). None of the index patients had antibodies against HIV. The overall prevalence of anti-HCV was 3.2% (2.5% in the absence of previous parenteral exposure). Sexual partners had a seroprevalence of 4.7% and non-sexual contacts, 2.5%. Among non-sexual contacts, parents showed the highest rate (4.2%). The mean duration of exposure in the anti-HCV-positive sexual partners was 17.3 +/- 8.5 years, vis-à-vis 9.2 +/- 7.4 years in the anti-HCV-negative sexual partners. We conclude that there is little risk of HCV infection through household contact. Although the form of transmission is not well identified, the duration of sexual activity suggests that the time needed to become infected is long.