Spread of hepatitis C virus infection within families

In 1995, the intrafamilial spread of hepatitis C virus (HCV) was evaluated among 1379 household contacts of 585 HCV antibody‐positive HCV RNA‐positive subjects (index cases) in Italy. All index cases were patients with histologically proven chronic liver disease. The presence of antibodies to HCV (anti‐HCV) was assessed by third‐generation enzyme‐linked immunosorbent assay (ELISA); the polymerase chain reaction (PCR) was used to test for HCV RNA. The overall anti‐HCV prevalence among household contacts of index cases was 7.3% (101/1379); it was 15.6% in spouses and 3.2% in other relatives (P<0.05; odds ratio (OR), 6.5; 95% confidence interval (CI), 3.5–8.6). Spouses married to index cases for longer than 20 years had a significantly higher anti‐HCV prevalence than those married 20 years or less (19.8%vs 8.0%; P<0.05; OR, 2.8; 95% CI, 1.5–5.3). Parenteral risk factors were more likely to be reported in anti‐HCV positive than in anti‐HCV negative household contacts. After adjustment for confounders by multiple logistic regression analysis, age greater than 45 years (OR, 3.1; 95% CI, 1.6–5.3) and any parenteral exposure (OR, 3.7; 95% CI, 1.7–8.1), were the only independent predictors of the likelihood of anti‐HCV positivity among household contacts. Spouses versus other relatives and length of marriage were both no longer associated. These findings suggest that sexual transmission does not seem to play a role in the intrafamilial spread of HCV infection.