HIV-positive women in developing countries could reduce the risk of transmitting the virus to their infants if they exclusively breast-feed rather than supplement breast milk with formula, animal milk or solid food, according to a study published in the March 31 edition of the Lancet, Reuters reports (Dunham, Reuters South Africa, 3/30).
The study, led by Hoosen Coovadia and Nigel Rollins of the Africa Centre for Health and Population Studies at the University of KwaZulu-Natal, enrolled 2,722 HIV-positive and HIV-negative women and 1,372 infants. The researchers compared the risks of vertical HIV transmission and survival rates for infants exclusively breast-fed with infants who received formula, animal milk or solid food in addition to breast milk (Coovadia et al., Lancet, 3/31). According to BBC News, 4% of the exclusively breast-fed infants had a risk of becoming HIV-positive between ages six weeks and six months (BBC News, 3/30). The study found that infants who received milk and solid food were 11 times more likely to become HIV-positive than infants who were exclusively breast-fed, London's Guardian reports. In addition, infants who received both formula and breast milk were twice as likely to become HIV-positive as exclusively breast-fed infants (Boseley, Guardian, 3/30). According to researchers, the higher risk of vertical transmission among infants who received solid food might be because proteins in the food facilitate entry of the virus into the gut wall (Reuters, 3/30). About 6.1% of the exclusively breast-fed infants died by age three months, compared with 15.1% of the infants who received other food sources (AFP/Yahoo! News, 3/29). According to the researchers, breast milk might reinforce and protect the mucus membrane lining of the intestines, serving as a barrier to HIV, Reuters reports. Rollins said that if women in developing countries exclusively breast-feed, about 50,000 to 100,000 infant deaths would be prevented annually. Rollins added, "For the health and well-being of her child, exclusive breast-feeding is more than likely going to protect the child both from transmission and the other risks to her child's survival" (Reuters, 3/30). In an accompanying comment piece, Wendy Holmes of the Centre for International Health and Felicity Savage of the Centre for International Health and Development write that the study's findings are a "breakthrough" that provide "crucial confirmatory evidence that" when HIV-positive women exclusively breast-feed, their infants have "only a low risk of infection with HIV." They add that the study's findings "emphasize that promotion of exclusive breast-feeding for all mothers and babies could prevent much pediatric HIV infection, as well as deaths from other causes" (BBC News, 3/30).