Investigation of a secondary syringe exchange program for homeless young adult injection drug users in San Francisco, California, U.S.A.

This study investigated an HIV prevention program for homeless young adult injection drug users (IDUs) that combined a secondary syringe exchange program (SEP) with community-level activities. Homeless young IDUs were recruited from street-based settings in San Francisco, and a structured questionnaire was administered. The secondary SEP operated in a circumscribed geographic area, and for analytic purposes respondents were assigned to the intervention site group if they primarily spent time in this area (n = 67), or the comparison site group if they primarily spent time elsewhere (n = 55). Almost all (96%) intervention site youth had used the secondary SEP in the past 30 days and were significantly more likely to regularly use SEP. In bivariate analysis, comparison site IDUs were more likely to share syringes, reuse syringes, share the cotton used to filter drugs, and use condoms with casual sex partners only inconsistently. In multivariate analysis, comparison site remained positively associated with sharing syringes (adjusted odds ratio [AOR], 3.748; 95% confidence interval [CI], 1.406-9.988), reusing syringes (AOR, 2.769; 95% CI,1.120-6.847), and inconsistent condom use with casual sex partners (AOR, 4.825; 95% CI, 1.392- 16.721). This suggests that the intervention was effective in delivering SEP services to homeless young adult IDUs, and that IDUs who frequented the intervention site had a lower HIV risk than comparison group IDUs.