People who inject drugs in intimate relationships: it takes two to combat HIV.

We reviewed papers published during the past 18 months (2012-2013) focusing on micro-social contexts of gender and power inequalities as drivers of HIV risks among people who inject drugs (PWID) in intimate heterosexual relationships. Although there has been a proliferation of social and behavioral research on the micro-social contexts of drug injection in heterosexual intimate relationships, there is still a gap in knowledge of these issues, particularly in low- and middle-income countries. Research has identified couple-based approaches for PWID in intimate relationships as an effective HIV prevention strategy to address micro-social contexts driving HIV risks. While HIV incidence has declined in many countries, prevalence remains at troubling levels among PWID and transmission from PWID to their sex partners is increasing in many parts of the world. HIV prevention among drug-using couples must address the importance of the relationship dyad and micro-social contexts.