Among babies of mothers infected with HIV, those exclusively breast fed for three months or more have no excess risk of HIV infection over six months than those who have never been breast fed, according to latest research. The results could have important implications for public health policy in developing countries, where the total avoidance of breast feeding is not a realistic option for the vast majority of women.
Anna Coutsoudis from the department of paediatrics and child health at the University of Natal, South Africa, carried out a prospective cohort study involving 551 pregnant women infected with HIV who chose whether to breast feed exclusively, use formula feed exclusively, or carry out mixed feeding after being counselled (AIDS 2001;15:379-87).
In 1999 Dr Coutsoudis published the early results of the study in the Lancet (1999;354: 471-6). The infants have now been followed up for 15 months, and the results confirm that infants exclusively breast fed had no excess risk of maternal transmission of HIV over six months when compared with infants who were not breast fed at all. Those at greatest risk were the infants fed on a mixture of breast milk and other foods and liquids.
Dr Coutsoudis concluded: “If these results are confirmed, then the public health benefits for HIV infected women in developing countries is considerable.”
The study is the first to separate women who exclusively breast feed from those who carry out mixed feeding. The mechanism through which exclusive breast feeding may be safer than mixed feeding is not known. Dr Coutsoudis said: “We favour the hypothesis that contaminated fluids and foods introduced in [babies who received mixed feeding] damage the bowel and facilitate entry into the tissues of HIV in breast milk.”
Patti Rundall, policy director of the pressure group Baby Milk Action, believes the new study has important implications. Bottle feeding was not a realistic policy for many women because of the costs and lack of clean water.
“It is estimated that 1.7 million babies have been passed the HIV virus through breast milk, but this has to be compared with the 1.5 million babies who die every year because they are not breast fed.”
Dr Felicity Savage, of the Department of Child and Adolescent Health and Development at the World Health Organization (WHO), said: “The study... is not good enough to enable the WHO to recommend that HIV positive women breast feed exclusively as first choice.”
Full story in News Extra at bmj.com