[Familial transmission of hepatitis C virus]

To establish the prevalence of antibodies to hepatitis C virus (HCV) among relatives and other persons cohabiting with HCV carriers, as an indication of the risk of intradomestic transmission.

A transversal study of series of clinical cases. A questionnaire was applied to the index cases (IC) and contact cases (CC), differentiating sexual contacts (SC) from non sexual contacts (NSC).

One hundred and sixty four IC and 533 CC were included. Information on parenteral risk factors, type of sexual relationship, period of exposure, and other epidemiological variables was obtained. Antibodies to HCV (HCV-Ab) were determined by 2nd generation ELISA.

In eighty eight IC (53.6%) no parenteral risk factors were found. In 99 IC (62.8%) a liver biopsy showed chronic hepatitis or cirrhosis. Twelve CC (2.25%) turned out to be HCV-Ab (+), a ratio above that found in our city (0.3%, p < 0.001), however the comparison should be taken with caution. No significant differences were found with respect to several epidemiological variables, including type of sexual relationship, and socioeconomic indicators, between CC HCV-Ab (+) and (-). Stage of liver disease in the IC and relationship between IC and CC did not increase the risk of being HCV-Ab positive. In HCVAb positive CC a higher proportion of parenteral risk factors (p < 0.001), elevated ALT (p < 0.001) and sharing of personal tools (p < 0.01) were observed.

Intrafamiliar transmission of HCV is poorly documented and it is related to the presence of parenteral risk factors. The actual prevalence of HCVAb in a general population is unknown, rendering difficult to make definite conclusions.