HIV incidence during breastfeeding and mother-to-child transmission in Cape Town, South Africa.

: Despite widespread concerns about HIV incidence in pregnant and postpartum women, there are few data from Africa on HIV acquisition in breastfeeding and subsequent mother-to-child transmission. We measured HIV incidence in a prospective cohort of 413 peripartum and breastfeeding women who tested HIV-negative during pregnancy. In 377 woman-years accrued postpartum (median duration of follow-up, 1 year), there were seven women infected after delivery (postpartum incidence, 1.86/100 person-years; 95% confidence interval 0.88-3.89) with transmission to 2/7 (28%) infants.