Method of feeding and transmission of HIV-1 from mothers to children by 15 months of age: prospective cohort study from Durban South Africa.

A prospective cohort study in King Edward V111th Hospital and McCords Hospitals in Durban South Africa was conducted to determine the risk of HIV transmission by infant feeding modality. A total of 551 HIV-infected pregnant women were enrolled in a randomized trial of vitamin A and divided into three groups: the exclusive never and mixed breast-feeders. Overall the findings confirmed that the pattern of breast-feeding influences the rate of postnatal transmission of HIV-1. In particular the absence of excess risk of mother-to-child transmission of HIV-1 among infants on exclusive breast-feeding compared to those who were not breast- fed was demonstrated. Moreover no difference was noted in risk factors for transmissions among the three feeding groups while the probability of detecting HIV at birth was similar. In connection the cumulative probabilities were similar up to 6 months in both never and exclusive breast-feeders while probabilities of mixed breast-feeders surpassed the 2 groups by 6 months. Cumulative probability remained smaller among exclusive breast-feeders by 15 months for 3 months or more than among other breast-feeders.