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.