Antiretroviral (ARV) drugs are widely used for HIV treatment and prevention, and may be used for other reasons in some populations. We analyzed ARV drug use and HIV drug resistance among young women enrolled in the HIV Prevention Trials Network (HPTN) 068 study. HPTN 068 was conducted in rural northeast South Africa and evaluated the impact of cash transfer on HIV incidence conditional on high school attendance (study period: 2011-2015).
In the main study, young women were enrolled in high school and were tested for HIV infection annually until their expected graduation date. Some women had a post-graduation follow-up visit 1-2 years later. ARV drug testing was performed using a qualitative assay based on high resolution mass spectroscopy that detects 20 ARV drugs in five drug classes. HIV genotyping was performed using the ViroSeq HIV-1 Genotyping System v2.8.
We analyzed two sample sets: (1) enrollment samples (2,526 women: 80 infected; 2,446 uninfected), and (2) samples from the first HIV-positive visit (162 seroconverters; 107 in the main study, 55 in the follow-up study). ARV drugs were detected in enrollment samples from 10 (12.5%) of 80 HIV-infected women (six had 1 NNRTI with 1 or 2 NRTIs; three had 1 NNRTI alone; one had 1 NRTI alone). ARV drugs were also detected in samples from 16 (9.9%) of 162 seroconverters (14 had 1 NNRTI with 1 or 2 NRTIs; two had 1 NNRTI alone). None of 2,446 HIV-uninfected women had ARV drugs detected. Among the 242 HIV-infected women (80 infected at enrollment; 162 seroconverters), 211 (87.2%) had viral loads >400 copies/mL. HIV genotyping results were obtained for 198 of the 211 women (67 infected at enrollment; 131 seroconverters); this included 7 (26.9%) of the 26 women who had ARV drugs detected. Eighteen (9.1%) of the 198 women had NNRTI resistance, including 9 (13.4%) of 67 women infected at enrollment and 9 (6.9%) of 131 seroconverters; five of the 18 women also had NRTI resistance.
In this cohort, 12.5% of the women who were HIV infected at enrollment and 9.9% of the women with new HIV infection were taking ARV drugs. ARV drugs were not detected in >2,400 HIV-uninfected women. Among women who were not virally suppressed, 9.1% had NNRTI resistance and 2.5% had multi-class resistance. This study provides novel information about ARV drug use and HIV drug resistance among young women in rural South Africa. These findings may help inform future studies using ARV drugs for HIV prevention and treatment in this population.