HIV risks associated with incarceration among injection drug users: implications for prison-based public health strategies.

Background: Recent policy announcements in Canada and the United States may potentially affect the risk environment for HIV transmission among incarcerated injection drug users (IDU). We sought to evaluate the potential impact of incarceration on HIV risk behaviour among the IDU enrolled in a prospective cohort study.

Methods: We examined patterns of incarceration among 1247 IDU participants enrolled in a 6-year prospective cohort study in Vancouver, Canada, and tested for potential associations between HIV risk behaviour and incarceration. Correlates of incarceration were identified using generalized estimating equations (GEE).

Results: At baseline, factors significantly associated with incarceration included daily injection heroin and injection cocaine use and inconsistent condom use with casual sexual partners. In a GEE analysis, factors independently associated with incarceration included: used syringe borrowing (adjusted odds ratio [AOR] = 1.36; [95% CI: 1.16-1.60]), used syringe lending (AOR = 1.31; [95% CI: 1.12-1.55]) and inconsistent condom use with casual sexual partners (AOR = 1.16; [1.02-1.33]). All variables P < 0.05.

Conclusions: In our study, incarceration was independently associated with HIV transmission and acquisition behaviours. These findings suggest that increased rates of incarceration of IDU may be associated with increased HIV transmission among this group.