High Rates of Baseline Drug Resistance and Virologic Failure among ART-naive HIV-infected Children in Mali

Limited data exist on drug resistance and antiretroviral treatment (ART) outcomes in HIV-1 infected children in West Africa. We determined the prevalence of baseline resistance and correlates of virologic failure (VF) in a cohort of ART naive HIV-1 infected children <10 years of age initiating ART in Mali. Reverse transcriptase and protease genes were sequenced at baseline (before ART) and at 6 months. Resistance was defined according to the Stanford HIV Genotypic Resistance database. VF was defined as viral load ≥1000 copies/mL after 6 months of ART. Logistic regression was used to evaluate factors associated with VF or death >1 month after enrollment. Post hoc, antiretroviral concentrations were assayed on baseline samples of participants with baseline resistance. 120 children with a median age 2.6 years (IQR: 1.6-5.0) were included. 88% reported no PMTCT exposure. At baseline, 27 (23%), 4 (3%), and none had NNRTI, NRTI or PI resistance, respectively. 39 (33%) developed VF and 4 died >1 month post-ART initiation. In multivariable analyses, poor adherence (OR 6.1, p=0.001), baseline NNRTI resistance among children receiving NNRTI-based ART (OR 22.9, p<0.001) and PI-based ART initiation among children without baseline NNRTI resistance (OR 5.8, p=0.018) were significantly associated with VF/death. Ten (38%) with baseline resistance had detectable levels of nevirapine or efavirenz at baseline; 7 were currently breastfeeding but only 2 reported maternal antiretroviral use. Baseline NNRTI resistance was common in children without reported NNRTI exposure and was associated with increased risk of treatment failure. Detectable NNRTI concentrations were present despite few reports of maternal/infant antiretroviral use.