TY - JOUR T1 - Incidence of hepatitis C virus infection among injection drug users during an outbreak of HIV infection JF - Canadian Medical Association Journal JO - CMAJ SP - 889 LP - 895 VL - 165 IS - 7 AU - David M. Patrick AU - Mark W. Tyndall AU - Peter G.A. Cornelisse AU - Kathy Li AU - Chris H. Sherlock AU - Michael L. Rekart AU - Steffanie A. Strathdee AU - Sue L. Currie AU - Martin T. Schechter AU - Michael V. O'Shaughnessy Y1 - 2001/10/02 UR - http://www.cmaj.ca/content/165/7/889.abstract N2 - Background: Beginning in 1994, Vancouver experienced an explosive outbreak of HIV infection among injection drug users (IDUs). The objectives of this study were to measure the prevalence and incidence of hepatitis C virus (HCV) infection in this context and to examine factors associated with HCV seroconversion among IDUs. Methods: IDUs recruited through a study site and street outreach completed interviewer-administered questionnaires covering subjects' characteristics, behaviour, health status and service utilization and underwent serologic testing for HIV and HCV at baseline and semiannually thereafter. A Cox proportional hazards model was used to identify independent correlates of HCV seroconversion. Results: As of Nov. 30, 1999, 1345 subjects had been recruited into the study cohort. The prevalence of anti-HCV antibodies was 81.6% (95% confidence interval [CI] 79.6% to 83.6%) at enrolment. Sixty-two HCV seroconversions occurred among 155 IDUs who were initially HCV negative and who returned for follow-up, for an overall incidence density rate of 29.1 per 100 person-years (95% CI 22.3 to 37.3). The HCV incidence remained above 16 per 100 person-years over 3 years of observation (December 1996 to November 1999), whereas HIV incidence declined from more than 19 to less than 5 per 100 person-years. Independent correlates of HCV seroconversion included female sex, cocaine use, injecting at least daily and frequent attendance at a needle exchange program. Interpretation: Because of high transmissibility of HCV among those injecting frequently and using cocaine, the harm reduction initiatives deployed in Vancouver during the study period proved insufficient to eliminate hepatitis C transmission in this population. ER -