Preventing HIV-1 transmission in breastfed infants in low resource settings: early HIV infection and late postnatal transmission in a routine prevention of mother-to-child transmission program in Yaounde, Cameroon.

Objective: To report on overall HIV-transmission rates [early and late postnatal transmission (LPNT)] in breastfed infants born to HIV-positive women.

Methods: Mother-baby pairs in a routine prevention of mother-to-child transmission program. Promotion of exclusive breastfeeding (EBF) coupled with access to antiretroviral treatment (ART) or prevention using antiretroviral (pARV). Early infant diagnosis using HIV-RNA/PCR or HIV-DNA/PCR >6 weeks. LPNT assessed 6 weeks after weaning in infant earlier tested negative.

Main Measurement: early HIV infection and LPNT.

Results: We included 285 infants for analysis; 89.5 % of mothers were receiving ART or pARV; 86% babies took daily pARV (median duration, 6 weeks). Exclusive breastfeeding (EBF) rate: 96% (median duration, 4 months). The cumulative transmission of HIV-1 was 2.8% at 8 weeks (95% confidence interval: 1.9-3.7). After weaning (abrupt 44%), 3 of 212 infants were HIV infected (1.4%). Nine-month cumulative HIV-transmission rate was 4.2% (1.5-6.9). Incidence of late postnatal HIV infection stood at 1.5/100 child-years of breastfeeding (BF). Cumulative risk of HIV transmission (8 weeks-9 months) was 1%.

Conclusion: Both promotion of EBF and access to antiretroviral therapy contribute to lower HIV transmission in breastfed infants in low resource settings.