Sexual relationships, secondary syringe exchange, and gender differences in HIV risk among drug injectors.

Injection drug use continues to place women at risk for human immunodeficiency virus (HIV) through both risky injecting practices and risky sexual behavior with male injection drug users (IDUs). Although attendance at syringe-exchange programs (SEPs) is protective against HIV, a recent study found that women attending SEPs who exchanged syringes for other people (secondary exchange) were at greater risk for HIV seroconversion, potentially through risky sexual behavior. We examined this question in a sample of 531 IDUs (175 women and 356 men) attending 23 SEPs in California in 2001. Findings indicated that women were more likely than men to engage in secondary exchange and were more likely to have IDU sexual partners. In multivariate analysis among women, secondary exchange was independently associated with distributive syringe sharing, not engaging in receptive sharing, and not exchanging sex for money or drugs. Multivariate analysis among men found that having an IDU sexual partner was associated with secondary exchange. Women's sexual risk behavior was not associated with secondary exchange, and although women's secondary exchange was associated with individual protection for injection-related behaviors, it may increase network risk. More information on network members is needed to understand gender differences in secondary exchange.