Factors associated with high transmission risk and detectable plasma HIV RNA in HIV-infected MSM on ART.

Summary HIV transmission risk is increased during antiretroviral therapy (ART) use if individuals are not virologically suppressed and engage in high risk transmission behaviour. Baseline data of HIV-infected men who have sex with men (MSM) with recent history of risky behaviour on ART for ≥3 months (n = 139) were evaluated to assess predictors of detectable viraemia and HIV transmission risk-taking behaviour. Twenty-four subjects had viral load (VL) >75 copies/mL and 12 had VL >1000 copies/mL. In multivariable regression analyses, subjects with VL >75 copies/mL were more likely to be Black (OR = 4.48, p = 0.007), have lower CD4 cell counts (OR = 0.727, p = 0.005) and have used methamphetamines in the last month (OR = 6.64, p = 0.019). Subjects with VL >1000 copies/mL were more likely to have lower CD4 cell counts (OR = 0.494, p = 0.004), report <90% adherence (OR = 7.94; p = 0.046) and have used methamphetamines in the last month (OR = 10.01, p = 0.034). Subjects with VL >75 copies/mL with the greatest transmission risk behaviour (n = 14) were more likely to be Black (OR = 8.00, p = 0.006), have lower CD4 cell counts (OR = 0.657, p = 0.009) and have used methamphetamines in the last month (OR = 5.20, p = 0.042). High risk HIV transmission behaviour with viraemia occurred in 10% of the cohort. Future efforts to reduce HIV transmission among MSM on ART will require combined interventions that target risk-taking behaviours and substance use.