Background: HIV Prevention Trials Network (HPTN) 061 enrolled black men who have sex with men in the United States. Some men with low/undetectable HIV RNA had unusual patterns of antiretroviral (ARV) drug use or had drugs detected in the absence of viral suppression. This report includes a comprehensive analysis of ARV drug use and drug resistance among men in HPTN 061 who were not virally suppressed.
Methods: The analysis included 169 men who had viral loads >400 copies per milliliter at enrollment, including 3 with acute infection and 13 with recent infection. By self-report, 88 were previously diagnosed, including 31 in care; 137 men reported no ARV drug use. Samples from these 169 men and 23 seroconverters were analyzed with HIV genotyping and ARV drug assays.
Results: Forty-eight (28%) of the 169 men had ≥ 1 drug resistance mutation (DRM); 19 (11%) had multiclass resistance. Sixty men (36%) had ≥ 1 ARV drug detected, 42 (70%) of whom reported no ARV drug use. Nine (23%) of 39 newly infected men had ≥ 1 DRM; 10 had ≥ 1 ARV drug detected. Unusual patterns of ARV drugs were detected more frequently in newly diagnosed men than previously diagnosed men. The rate of transmitted drug resistance was 23% based on HIV genotyping and self-reported ARV drug use but was 12% after adjusting for ARV drug detection.
Conclusions: Many men in HPTN 061 had drug-resistant HIV, and many were at risk of acquiring additional DRMs. ARV drug testing revealed unusual patterns of ARV drug use and provided a more accurate estimate of transmitted drug resistance.