Involved factors in the intrafamilial spread of hepatitis C virus.

To investigate the risk of non-parenteral HCV infection, sera from 302 relatives of 120 anti-HCV positive subjects were tested for the presence of anti-HCV antibodies. For the sake of comparison, sera from 17,000 blood donors were also assayed. The prevalence of HCV positivity was 4.3% in household contacts, compared to 0.78% in the donor population, indicating a significantly higher risk of infection for family members. Close personal contact may not be as critical a factor for infection as is duration of the disease.