HIV infection among MSM who inject methamphetamine in 8 US cities

Background and Aims: Men who have sex with men (MSM) and inject drugs are at risk for HIV infection. Although research exists on non-injection methamphetamine (meth) use and sexual risk among MSM, less is known about meth injection and its association with HIV infection among MSM who inject drugs. Methods: We analyzed data from men aged ≥18 years who reported injecting drugs and male-to-male sexual contact. Men were recruited using respondent-driven sampling, interviewed, and tested for HIV during the 2012 and 2015 cycles of National HIV Behavioral Surveillance among persons who inject drugs. We included data from 8 cities where ≥10 MSM reported meth as the primary drug injected. We assessed differences in demographic characteristics, past 12 months risk behaviors, and HIV infection between MSM who primarily injected meth and those who primarily injected another drug. Results: Among 961 MSM, 33.7% reported meth as the drug they injected most often. Compared to MSM who primarily injected other drugs, MSM who primarily injected meth were more likely to have had ≥5 condomless anal sex partners, have been diagnosed with syphilis, and were less likely to report sharing syringes. In multivariable analysis, injecting meth was associated with being HIV-positive (adjusted prevalence ratio 1.48; 95% confidence interval 1.08–2.03). Including number of condomless anal sex partners in mediation analysis rendered this association no longer significant. Conclusions: HIV prevalence among MSM who primarily injected meth was almost 50% higher than among MSM who primarily injected other drugs, and this association was mediated by sexual risk.