HIV controllers are able to suppress viral replication to low levels without antiretroviral (ARV) therapy. The HIV Prevention Trials Network (HPTN) 068 trial was conducted in a rural area in South Africa and evaluated the impact on HIV incidence of a cash transfer conditional on high school attendance (study period: 2011-2015). The trial enrolled 81 HIV-infected and 2,448 HIV-uninfected women who were followed annually until their expected graduation date; some women had a post-graduation follow-up visit 1-2 years later. Overall, 164 women acquired HIV infection (seroconverters). We evaluated the frequency of HIV controllers in this cohort.
HIV viral load (VL) testing was performed using the RealTime HIV-1 Viral Load assay (limit of quantification: 40 copies/mL). ARV drug testing was performed using a qualitative assay that detects 20 ARV drugs in 5 drug classes. HIV genotyping was performed for samples with VLs >400 copies/mL using the Viroseq HIV-1 Genotyping System, v2.8. Women were classified as viremic controllers if they had a VL ≤ 2,000 copies/mL at study enrollment or their first HIV-positive visit (for seroconverters), and maintained this level of viral suppression for at least 12 months in the absence of ARV drug use. Statistical analysis was performed using SAS software.
Thirty-four (13.9%) of the 245 HIV-infected women had VLs ≤2,000 copies/mL at the first visit tested with no ARV drugs detected at that visit (12 at enrollment; 22 at their first HIV-positive visit; three seroconverters had VLs <40 copies/mL at this visit). Fifteen of the 34 women were followed for ≥12 months. Twelve of the 15 women were classified as viremic controllers (seven who were HIV-infected at enrollment; five who seroconverted during the study; one woman had a single VL value ≥2,000 copies/mL during follow-up; median follow-up: 20 months, range 13-42 months). These women had sustained viral suppression with no ARV drugs detected during follow-up. Only one of 12 viremic controllers had HIV drug resistance.
In this cohort of young women in rural South Africa, at least 5% were able to control viral replication to low levels in the absence of ARV drug use (8.6% of women who were HIV infected at enrollment and 3.1% of the seroconverters). These data may help inform future studies of HIV treatment and prevention in this high-incidence population.