HIV-1 drug resistance surveillance among parturient women on anti-retroviral therapy in the Eastern Cape, South Africa: Implications for elimination of mother-to-child transmission

Background: The emergence of HIV drug resistance poses a significant threat to achieving the goal of elimination of mother-to-child transmission. Objectives: We assessed the extent and patterns of HIV-1 drug resistance mutations (DRMs) within the context of the public sector prevention of mother-to-child transmission (PMTCT) programme in the Eastern Cape, South Africa. Study design: We conducted analysis of the Pol sub-genomic sequence of RNA extracted from plasma samples of women with probable virological failure at delivery between January and May 2018 from two large maternity centres in the Eastern Cape using standard protocols. Partial pol gene covering 1030bp were amplified and sequenced according to previously reported protocol. DRMs were determined by submitting the generated partial pol sequences to the Stanford drug resistance database for query on mutations associated with drug resistance in HIV viruses. We examined the correlates of DRMs using bivariate analysis. Results: The age of parturient women ranged from 16 to 43 years. The majority of the parturient women were currently on Efavirenz-based regimen (first line ART) (82.5%) and had been on ART for more than 12 months (65.0%). The prevalence of DRMs was 72.5% (n = 58). The CD4 count demonstrated a negative linear association with the DRMs (p = 0.002). The predominant DRMs were K103 N (n = 43; 74.1%), M184 V (n = 28; 48.3%) and K65R (n = 11; 19%). Among the parturient women on EFV-based regimen treatment; 79.1% already had K103 N while nine patients on protease inhibitor-based regimen still harboured K103 N. The majority of the M184 V mutations were observed in parturient women on first line regimen (n = 23; 82.1%). Conclusions: We found a high prevalence of DRMs in women delivering their index babies at high viral loads in the study settings. Drug resistance surveillance using point-of-care reverse transcriptase-PCR strategies for the screening of pregnant women on ART could be a game-changer in the resource-constrained settings.