HIV among injecting drug users: Current epidemiology, biologic markers, respondent-driven sampling, and supervised-injection facilities

Purpose of review: To describe recent research done primarily during the past 12 months (i.e., primarily in 2008) on the epidemiology of HIV infection among injecting drug users (IDUs). Recent findings: Major research developments include a global assessment of HIV infection among IDUs and evidence of a transition from epidemics concentrated among IDUs to generalized, heterosexual epidemics in eastern Europe and Asia. Intervention research also includes several studies of supervised-injecting facilities. Methodological research includes respondent-driven sampling and the use of hepatitis C virus and herpes simplex virus-2 as biomarkers for injecting and sexual risk. Summary: There have been important advances in research during the past year, but HIV infection continues to spread rapidly across many areas of the world among IDUs and their nondrug-using sex partners.