Prevalence and associated factors of hepatitis C infection (HCV) in a multi-site Canadian population of illicit opioid and other drug users (OPICAN).

BACKGROUND Hepatitis C virus (HCV) infection is highly prevalent in illicit drug user populations, with three in four new HCV infections related to this risk behaviour and a growing HCV disease burden in Canada. Using data from a multi-site cohort study of illicit opioid users in five Canadian cities (OPICAN), this paper explores the prevalence and predictors of HCV status in this high-risk population. METHODS HCV status of cohort participants was assessed by salivary antibody test. Univariate relationships of HCV status with select variables were examined on the basis of cohort baseline data, and subsequently multivariate models using logistic regression to determine independent predictors of HCV status were generated. RESULTS 54.6% of the analysis sample (n=482) was HCV positive. Significant differences in terms of HCV prevalence existed across the sites. Significant variables in the final stepwise logistic regression model included age, site (Toronto), unprotected sex, injecting drug use, drug treatment and incarceration in past year, in addition to opioid use in combination with non-opioids. DISCUSSION Besides drug injecting, various other socio-behavioural factors were associated with HCV status in our cohort. On this basis, interventions focusing solely on injection risks are overly limited in scope to prevent HCV transmission in the high-risk population of illicit drug users and need to be broadened. Prevention efforts should also target young injectors as a priority.