When a baby dies in a hospital in Malawi, Africa, you can hear everything. Family members, known as guardians, hurl their bodies against the ground, beating the floor with their fists and uttering heart-wrenching sobs. Dr. Charles van der Horst knows. The UNC-Chapel Hill professor of medicine spends three months each year in Africa, researching the transmission of HIV, the deadly virus that causes AIDS, to infants.
He's also the senior author of a study that details two therapies that help shield babies from contracting HIV from breast milk. Published Thursday in the New England Journal of Medicine, the study shows that giving either a triple drug cocktail of HIV-fighters called antiretrovirals to mothers or a single antiretroviral to suckling infants greatly reduces the risk of transmission.
Of the two therapies, researchers recommend the infant option for safety and economic reasons. For places like Malawi, the site of the study, mother-to-child transmission via breast milk is a chief concern. Every year, 200,000 babies are infected this way, van der Horst said.
If an HIV-positive mother in a developing African nation is afraid to breast-feed, the solution is not as simple as switching to baby formula. Not only is formula expensive, but the water from which it is made often contains disease-causing bacteria.
"The mortality rate actually increases with formula because many babies die of pneumonia or diarrheal disease," van der Horst said. "We need a way to allow women to continue to breast-feed [without transmitting HIV]."
The researchers' quest to find an effective way of combating this problem, called the Breastfeeding, Antiretrovirals and Nutrition Study, was the largest to date, conceived nine years ago and involving 2,369 HIV-positive new mothers.
Each breast-feeding woman was randomly assigned to one of three groups. In the maternal group, mothers received a combination of three antiretrovirals. In the infant group, babies got a liquid dose of an antiretroviral called nevirapine every day for 28 weeks, with dosage increasing with babies' age. In the control group, neither mom nor baby was administered any drug after delivery.
Dr. Laura Guay, vice president for research at the Elizabeth Glaser Pediatric AIDS Foundation, called the study a critical research landmark.
"It's huge, high-quality and the first to look at both interventions in the same context, which makes it much easier to compare them," she said.
At the end of 28 weeks, mothers and babies who got antiretrovirals fared significantly better than those who didn't, with 53 percent fewer babies in the maternal group and 74 percent fewer in the infant group infected by HIV.
It's an impressive time for mother-to-child transmission research. In the same issue of the New England Journal of Medicine this week, a second study from the Harvard School of Public Health found that administering a highly active antiretroviral therapy to mothers starting during pregnancy, as opposed to after delivery, led to a 99percent drop in transmission. "The two studies together provide the tools to protect infants during breast-feeding," said Roger Shapiro, lead author of the Harvard study. "It's now up to us to work on the implementation."