INFANT-FEEDING AND RISK OF MOTHER-TO-CHILD TRANSMISSION OF HIV-1 IN SAO-PAULO STATE, BRAZIL

Although vertical transmission of HIV-1 can occur through breast-feedi ng, little is known about the effect of colostrum, duration of breast- feeding, mixing feeding, and nipple pathology. We used retrospective c ohort data to examine the association between breast-feeding-related f actors and transmission of HIV-1 from mother to child in Sao Paulo Sta te, Brazil. Information on maternal and postnatal factors was collecte d by medical record review and interview. Infection status was determi ned for 434 children by anti-HIV-l tests performed beyond 18 months of age or diagnosis of AIDS at any age. Among 168 breast-fed children, t he risk of transmission of HIV-1 was 21%, compared with 13% (p = .01) among 264 children artificially fed. Breastfeeding was independently a nd significantly associated with mother-to-child transmission of HIV-1 after controlling for stage of maternal HIV-1 disease (odds ratio [OR ] = 2.2; 95% confidence interval [CI], 1.3-3.8). A trend was shown tow ard an increased risk of transmission with longer duration of breast-f eeding, a history of bleeding nipples, and introduction of other liqui d food before weaning, but these associations were not statistically s ignificant. History of colostrum intake or cracked nipples without ble eding were not associated with transmission. Most of the women who bre ast-fed were unaware of their HIV-1 infection status at the time of de livery. Avoidance of mixed feeding and withholding of breast-feeding i n the presence of bleeding nipples should be considered in further res earch as strategies to reduce postnatal transmission of HIV-1 in setti ngs in which safe and sustainable alternatives for breast-feeding are not yet available.