Social circumstances of initiation of injection drug use and early shooting gallery attendance: implications for HIV intervention among adolescent and young adult injection drug users.

To determine correlates of early shooting gallery (SG) attendance and HIV prevalence and incidence among new injection drug users (IDUs), baseline data from a prospective cohort study of street-recruited IDUs aged 15 to 30 years and injecting < or =5 years were used to identify early high-risk practices and salient social circumstances associated with early SG attendance to help in the design of innovative intervention strategies. Of 226 IDUs, 10.6% were HIV-seropositive, and HIV incidence was 6.6 per 100 person-years (95% CI: 2.2-13.3). Median age was 25 years, and most participants were African American (64%) and female (61%). Using multiple logistic regression, early SG attendees were three times as likely to be HIV-seropositive and twice as likely to be initiated by an older IDU. Early SG attendees were also five times more likely to share injection equipment and over three times more likely to report a high-risk injecting network soon after initiating injection. These data suggest that young new IDUs who attend SGs early tend to be initiated by older high-risk IDUs and to share and inject within a high-risk social setting early on as well. Hence, older IDUs may serve as a bridge group to SGs, transmitting HIV from older to younger IDUs.