Sexual and other noninjection risks for HBV and HCV seroconversions among noninjecting heroin users

Background. Many heroin users do not inject drugs but may still be at risk of infection with human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV), via sexual or other noninjection-related activity. Methods. Noninjecting heroin users (NIUs) in New York City who were recruited and prospectively followed during March 1996-February 2003 were tested for anti-HIV, anti-hepatitis B core antigen, and anti-HCV and were interviewed about their sexual and other noninjecting risk. A seroconversion is represented by the first positive test result after the last negative test result. Hazard ratios (HRs) (P < .05) were estimated by use of Cox proportional hazards regression. Results. Of 253 HIV-negative participants, 2 seroconverted (0.29/100 person-years at risk [pyar]); of 184 HBV-negative participants, 16 (3.3/100 pyar); and, of 219 HCV-negative participants, 16 (2.7/100 pyar). Independent predictors of seroconversion were, for HBV, being a female who engages in unprotected receptive anal sex (HR, 6.8), having short-term sex partners (HR, 6.2), and being a male with male sex partners (HR, 5.7); for HCV, being a male who receives money/drugs for sex (HR, 5.6) and sharing noninjecting crack-use equipment (HR, 4.5). Conclusions. NIUs are at considerable risk of HBV infection via high-risk sex; and, for HCV, via high-risk sexual activity and the sharing of noninjecting crack-use equipment. Interventions in NIUs must seek to reduce high-risk sexual activity and the sharing of noninjecting drug-use equipment.