Maternal, infant ART drives down mother-to-child HIV transmission through breast-feeding, studies show

Jun 18 2010

According to two new studies, "giving pregnant and nursing women triple antiretroviral drug therapy, or treating breast-fed infants with an antiretroviral medication, can dramatically cut transmission rates, enabling moms to both breast-feed and to protect nearly all children from infection," HealthDay News/Bloomberg Businessweek  reports (Goodwin, 6/16).

"Taking highly active antiretroviral therapy (HAART) from early in the third trimester of pregnancy through weaning prevents mother-to-child HIV transmission, according to a study in Botswana," published Thursday in the New England Journal of Medicine, Reuters reports.

For the study, researchers "randomly assigned [560] women with CD4 cell counts of 200 or more to receive either a nucleoside reverse-transcriptase inhibitor (NRTI) or a protease inhibitor (PI), while [a total of 170] women with lower CD4 counts or with AIDS-defining illnesses received standard of care treatment for Botswana," the news service writes. Infants were also administered a single dose of the antiretroviral nevirapine at birth and zidovudine for 4 weeks, according to Reuters (6/16).

According to the study, rates of HIV transmission were similar at delivery and throughout breast-feeding across all study groups, with 1.1 percent of all infants becoming infected with HIV by 6 months of age (Shapiro et al., 6/17).

"This is the lowest rate of mother-to-child transmission in a study from Africa, or among breastfeeding infants," study lead author Roger Shapiro, an associate professor of medicine at Harvard Medical School, said, the Hindu reports (6/17).

"The findings are good news for many HIV-infected mothers, who 'were faced with a choice between breastfeeding and a high risk of infecting their children with HIV, or using formula and risking high infant morbidity and mortality from other diseases associated with not breastfeeding,' Max Essex, a professor of health sciences and chair of the Harvard School of Public Health AIDS Initiative and coauthor of the study, said in a prepared statement," according to Scientific American's "Observations" blog. "This study provides a more satisfactory solution," he added (Harmon, 6/16).

In a separate New England Journal of Medicine study, "researchers randomly assigned 2,369 breastfeeding mothers (and their infants) in Malawi to one of three groups: one in which the mother alone received antiretroviral therapy for the first seven months after the birth of the baby, another in which the infants were given nevirapine … for seven months, and a third, control group, in which medication was delivered to mothers and babies only at birth and for the first week postpartum," Scientific American's "Observations" blog continues. The study revealed that "[a]fter seven months, the infant-treatment method had a 74 percent success rate in preventing transmission through breastfeeding (and the maternal-treatment method was 53 percent effective)" (6/16).

Though both interventions were effective at preventing mother-to-child transmission of HIV, study author Charles M. van der Horst, a professor of medicine and infectious diseases at the University of Carolina at Chapel Hill, "believes for the poorest of the poor in Africa, the infant regimen is more feasible than triple-drug therapy for moms, which requires testing and monitoring and medical facilities to do so," HealthDay News/Bloomberg Businessweek notes.

"For infants, nevirapine is widely available and inexpensive relative to other drugs, and the once-a-day dosage is easy to carry out, he said," according to the news service (6/16).

"More than 90% of the 430,000 human immunodeficiency virus type 1 (HIV-1) infections in children each year occur in sub-Saharan Africa, where HIV-1 acquisition through breast milk accounts for more than 40% of infections. However, in Africa, breast-feeding is a cornerstone of child survival," the author of an accompanying New England Journal of Medicine editorial writes before outlining the major findings of the two studies.

"Given two similarly effective interventions, the choice of prophylaxis involves several considerations, including relative costs, feasibility, and risks and benefits," the author writes. "Debate about which intervention is optimal and most effective should not be used to justify inaction. Success will be tied less to what regimen is provided than to the integration of services for the identification, care, and treatment of women with HIV-1 infection and their infants."

The editorial concludes,"The implementation of these new options for the perinatal prevention of HIV-1 infection in resource-limited countries offers a unique opportunity to link prevention and treatment efforts, rather than view these as competing efforts. We now have the tools to make a considerable difference in controlling the pediatric HIV-1 epidemic. A generation of children awaits our actions" (Mofenson, 6/17).