Correlates of HCV seropositivity among familial contacts of HCV positive patients.

Background: Determinants of intrafamilial HCV transmission are still being debated. The aim of this study is to investigate the correlates of HCV seropositivity among familial contacts of HCV positive patients in Italy.

Methods: A cross-sectional study was conducted with 175 HCV positive patients (index cases), recruited from Policlinico Gemelli in Rome as well as other hospitals in Central Italy between 1995 and 2000 (40% female, mean age 57 +/- 15.2 years), and 259 familial contacts. Differences in proportions of qualitative variables were tested with non-parametric tests (chi2, Yates correction, Fisher exact test), and a p value < 0.05 was considered significant. A multivariate analysis was conducted using logistic regression in order to verify which variables statistically have an influence on HCV positivity in contact individuals.

Results: Seropositivity for HCV was found in 8.9% of the contacts. From the univariate analysis, risk factors significantly associated to HCV positivity in the contacts were: intravenous drug addiction (p = 0.004) and intercourse with drug addicts (p = 0.005). The only variables associated significantly and independently to HCV seropositivity in patients' contacts were intercourse with drug addicts (OR = 19.28; 95% CI: 2.01 - 184.94), the retirement status from work (OR = 3.76; 95% CI: 1.17 - 11.98), the time of the relationship (OR = 1.06; 95% CI: 1.00 - 1.11) and tattoos (OR = 7.68; 95% CI: 1.00 - 60.20).

Conclusion: The present study confirms that having intercourse with a drug addict is the most significant risk factor for intrafamilial HCV transmission. The association with retirement status from work could be related to both a long-term relationship with an index case and past exposure to common risk factors.