Structural interventions to reduce HIV transmission among injecting drug users

OBJECTIVE: To review current knowledge of 'structural' interventions to reduce HIV transmission among injecting drug users. Structural interventions are defined as programs or policies that change the environments in which risk behavior occurs, without attempting to change knowledge, attitudes or social interaction patterns of the persons at risk. Structural interventions may either facilitate enactment of existing motives to avoid HIV transmission or make enacting risk behavior more difficult. METHODS: Nonquantitative literature review. RESULTS AND CONCLUSIONS: Preventing HIV infection among injecting drug users must be considered within the context of the continuing global spread of psychoactive drug use, and injecting drug use in particular. Some policies that are designed to reduce drug use may tend to increase HIV transmission among persons who do inject drugs. Evaluation of structural interventions can be difficult, as populations of drug users are usually the relevant unit of analysis. Typically, pre versus post comparisons must be used, hopefully with multiple pre and post data points. Structural interventions are often associated with 'large effects', increasing confidence that the intervention is the cause of the reduction in HIV-risk behavior. Increasing the availability of sterile injection equipment, through pharmacy sales or syringe exchange or both, is the most common and best-studied structural intervention for injecting drug users. The studies to date indicate that this usually, but not always, leads to large reductions in HIV-risk behavior. Involving drug users in the design and implementation of HIV-prevention programs can be considered a 'meta-structural' intervention that should lead to programs with increased effectiveness.