Human Immunodeficiency Virus May Be Transmitted From Mothers to Their Infants Through Breastfeeding

Abstract

A study of mothers and their infants in Rwanda indicates that HIV can be transmitted postpartum possibly through breastfeeding. In order to examine the frequency and risk factors for postpartum HIV seroconversion researchers studied 212 seronegative mothers and their infants recruited from the maternity ward at a hospital in Kigali. At the time of delivery researchers tested blood samples from the mother and the umbilical cord for HIV antibodies. Following delivery the women received follow-up visits from social workers and physicians. After a 24-month period 16 of the 212 women had become HIV positive. Each of the mothers who seroconverted was matched for age and parity with 3 repeatedly seronegative mothers who became the controls. researchers administered a standard blinded questionnaire in order to establish the risk factors for postnatal seroconversion. Researchers found that the women who seroconverted were less likely to be legally married or involved in common-law unions and were more likely to have remained sexually abstinent longer after delivery--in Rwanda an indication of unstable sexual relations. 9 of the 16 infants whose mothers seroconverted also became infected during the same 3 month period as their mothers. 8 of these 9 infants had tested negative at the time of birth. 4 of the infants seroconverted during the first 3 months postpartum while the other 4 seroconverted after 2 months. All but one subject and all controls had been breastfed. Unable to identify any other means of transmission the researchers concluded that postnatal transmission occurred through breastfeeding a conclusion supported by evidence that HIV has been isolated from breast milk and colostrum. Depending on whether the 4 infants who seroconverted during the first 3 months are included (they could have become infected during delivery) the rate of postnatal transmission could range between 36% and 53%.