Operational effectiveness and 36 week HIV-free survival in the South African programme to prevent mother-to-child transmission of HIV-1

Objective: Previous studies on the operational effectiveness of programmes to reduce transmission of HIV from mother-to-child (PMTCT) in Africa have generally been hospital-based pilot studies with short follow-up periods. Method: Prospective cohort study to evaluate the routine operational effectiveness of the South African National PMTCT Programme, primarily measured by HIV-free survival at 36 weeks post-delivery. Three of eighteen pilot sites participating in the programme were selected as they reflected differences in circumstances, such as HIV prevalence, socioeconomic status and rural-urban location. A total of 665 HIV-positive mothers and their infants were followed. Results: HIV-free survival at 36 weeks varied significantly across sites with 84% in Paarl, 74% in Umlazi and 65% in Rietvlei (P=0.0003). Maternal viral load was the single most important factor associated with HIV transmission or death [hazard ratio (HR), 1.54; 95% confidence interval (CI), 1.21-1.95]. Adjusting for health system variables (fewer than four antenatal visits and no antenatal syphilis test) explained the difference between Rietvlei and Paarl (crude HR, 2.27; 95% CI, 1.36-3.77; adjusted HR, 1.81; 95% CI, 0.93-3.50). Exposure to breastmilk feeding explained the difference between Umlazi and Paarl (crude HR, 1.74; 95% CI, 1.06-2.84; adjusted HR, 1.41; 95% CI, 0.81-2.48). Conclusion: Ever breastfeeding and underlying inequities in healthcare quality within South Africa are predictors of PMTCT programme performance and will need to be addressed to optimize PMTCT effectiveness. (c) 2007 Lippincott Williams & Wilkins.