Postnatal HIV vertical transmission and the impact of infant feeding choice in the ART era.

Background: Mixed feeding (MF) among HIV-exposed infants is a common practice in sub-Saharan Africa. Evidence suggests that MF is an additional risk for postnatal HIV transmission, even with antiretroviral therapy (ART). Objectives: To determine the risk of HIV transmission by infant feeding modality. Method: We searched for studies focusing on mothers living with HIV and their infants, and their feeding modality. The primary outcome was postnatal HIV transmission. Results: Nine studies were identified from 570 reports. Overall, postnatal HIV transmission was measured at varying time points across the studies. Five studies reported transmission rates at 12 months, estimates ranged from 0% to 7%. Higher transmission rates were reported at 18-24 months, peaking at 11.6%, compared to a peak of 5% at 6 months. Adherence to maternal ART was reported in three studies ranging from 84% to 98%. Exclusive breastfeeding (EBF) duration was established in seven studies ranging from 51% to 97% at 6 months, with early complementary feeding introduced as early as 2 weeks. Two studies reported increased risk in HIV transmission associated with MF: 4-6-fold higher risk of transmission in MF compared to EBF infants. Conclusion: Reduced risk of postnatal HIV transmission was revealed in mothers on ART, and EBF, supporting WHO recommendations, two studies showed the presence of MF increased the risk of postnatal transmission. There is limited information on the actual risk of postnatal transmission associated with MF in mothers adhering to ART with suppressed viral loads.