Risk factors for hepatitis C virus infection: a population-based case-control study

In 30% of patients with hepatitis C virus, the source of infection is unknown. Objective - To identify the risk factors of infection by hepatitis C virus in a case-control study. Methods - Cases had positive hepatitis C virus serology, and were living in Fecamp (Normandy, France). Controls (2 for each case) were age and sex-matched subjects with negative hepatitis C virus serology, living in Fecamp. Demographic, medical, professional, and environmental data were collected. Statistical analysis included chi(2) or Fisher's exact test and multiple logistic regression. Results - The risk factors of hepatitis C virus by univariate analysis were: history of transfusion, high number of sexual partners, hepatitis C virus infection in a relative, history of digestive or genitourinary surgery, an invasive medical procedure, digestive endoscopy, biopsy, lumbar or pleural puncture, medical care after an accident, injections, multiple deliveries or abortion. Risk factors of hepatitis C virus infection by multivariate analysis: hepatitis C virus infection in a relative (Odds ratio: 4.58), history of transfusion (Odds ratio: 2.32), of a surgical procedure (Odds ratio: 2.50), of medical care after an accident (Odds ratio: 1.51), of injections (Odds ratio: 2.24). Conclusion - Our results suggest the possible nosocomial transmission of hepatitis C virus. Intrafamilial transmission is also possible.