Breast-milk transmission of HIV-1 and early cessation of breastfeeding

Breast-milk transmission of HIV-1 contributes to a substantial number (40-50%) of infant HIV-1 infections worldwide. Late postnatal transmission risk estimates (transmission risk similar to 5%) represent perhaps the minority of breast-milk HIV-1 transmission overall (transmission risk 14%) because they do not include transmission occurring in the first 3 months of life. A recently completed clinical trial should yield useful information on the frequency and timing of breast-milk HIV-1 transmission. Decision-making regarding breast-milk avoidance or early cessation of breastfeeding will need to take into account these estimates and the feasibility of provision of safe alternatives. Worldwide, most infants exposed to HIV-1 live in areas where breastfeeding is prevalent and breast-milk alternatives have been considered risky or infeasible. As new perinatal HIV-1 intervention strategies are developed for these settings, breast-milk HIV-1 transmission will need to remain a high research priority.