Hepatitis C virus infection: prevalence, predictor variables and prevention opportunities among drug users in Italy.

The study assessed rates and predictor variables of hepatitis C virus (HCV) infection among drug users receiving pharmacological treatment for opiates addiction. There was a large cohort study in 16 public centres for drug users in north-eastern Italy, with data collected by standardized face-to-face interviews between February 2001 and August 2001. Of 1095 participants, 74.2% were HCV seropositive. Anti-HCV status was independently associated with duration of drug use of over 10 years, injecting as a route of drug administration, and hepatitis B virus (HBV) and human immunodeficiency virus (HIV) seropositivity. Further statistical analysis was conducted by dividing the subjects on the basis of the duration of heroin use: more or <10 years. In the multivariate analyses, route of drug administration and HBV status were associated with HCV seropositivity among both groups. Less education was associated with HCV among the shorter term drug users. HIV status and having a sexual partner with a history of drug use were associated with HCV seropositivity among the longer term drug users. Half of the short-term heroin users were still HCV seronegative when starting treatment, suggesting opportunities for reducing new HCV infections. Remarkable was the relationship between vaccination for hepatitis B and HCV serostatus. Being HBV seropositive was strongly associated with being HCV seropositive. But heroin users who had been vaccinated for HBV were not significantly more likely to be HCV seropositive than heroin users who were HBV seronegative. HBV vaccination does not provide biological protection against HCV; however, vaccinating heroin users against HBV may help to create a stronger pro-health attitude among heroin users, leading to a reduction in HCV risk behaviour.