Impact of breastfeeding, maternal antiretroviral treatment and health service factors on 18-month vertical transmission of HIV and HIV-free survival: results from a nationally representative HIV-exposed infant cohort, South Africa

BackgroundWe analysed the impact of breastfeeding, antiretroviral drugs and health service factors on cumulative (6 weeks to 18 months) vertical transmission of HIV (MTCT) and ‘MTCT-or-death’, in South Africa, and compared estimates with global impact criteria to validate MTCT elimination: (1) 6 weeks to 18 months) was 1.7% (95% CI 1.2% to 2.4%). Cumulative ‘MTCT-or-death’ was 6.3% (95% CI 5.5% to 7.3%); 81% and 62% of cumulative MTCT and ‘MTCT-or-death’, respectively, occurred by 6 months. Postnatal MTCT increased with unknown maternal CD4-cell-count (adjusted HR (aHR 2.66 (1.5–5.6)), undocumented maternal HIV status (aHR 2.21 (1.0–4.7)) and exclusive (aHR 2.3 (1.0–5.2)) or mixed (aHR 3.7 (1.2–11.4)) breastfeeding. Cumulative ‘MTCT-or death’ increased in households with ‘no refrigerator’ (aHR 1.7 (1.1–2.9)) and decreased if infants used nevirapine at 6 weeks (aHR 0.4 (0.2–0.9)).ConclusionsWhile the