Opportunities for sexual transmission of antiretroviral drug resistance among HIV-infected patients in care.

Objective: To assess opportunities for transmitted drug resistance (TDR), we examined sexual risk behaviours, HIV viraemia and antiretroviral resistance among patients in care.
Design: A retrospective, cross-sectional analysis of clinical cohort data.
Methods: For 244 UNC Center for AIDS Research HIV Clinical Cohort participants, demographic and behavioural data were obtained during in-person interviews between 2000 and 2011. Genotypic resistance tests were interpreted using WHO surveillance drug resistance mutations (SDRMs). Log-linear binomial regression was used to evaluate associations with TDR risk, defined as unprotected sex in the prior 6 months, HIV RNA at least 400 copies/ml and at least one SDRM.
Results: Participants included 91 (37%) women and 153 men, of whom 92 (60%) were MSM. Median age was 43 years; 70% were Black (n = 171). Most (97%) were antiretroviral-experienced; 44% had exposure to more than four regimens. Among 204 individuals on antiretrovirals, 42% reported suboptimal adherence and 29% were viraemic. Over half of participants had at least one SDRM (n = 131); 26 (11%) had triple-class resistance. Overall, 70% were sexually active, and 55% used condoms inconsistently. Thirty (12%) reported unprotected sex during periods of drug-resistant viraemia. Higher TDR risk was associated with prior homelessness [adjusted prevalence ratio (aPR) 2.20, 95% confidence interval (CI) 1.16-4.18], active substance use (aPR 3.12, 95% CI 1.47-6.62) and nonsignificantly with MSM (aPR 1.75, 95% CI 0.93-3.28).
Conclusion: A small but significant proportion of clinic patients with drug-resistant HIV engage in sexual behaviours that place others at risk for TDR. Targeted efforts in secondary prevention could have an impact on TDR incidence, over time.