In a study published in this week's New England Journal of Medicine, researchers report on a drug cocktail that they say reduces the risk of mother-to-child transmission of HIV through breastfeeding, while a second study challenges conventional notions of how long HIV infected mothers should breastfeed their infants to reduce the risk of transmission. VOA's Jessica Berman has more.

HIV virus

Experts say the average mother in Africa breastfeeds her infant for 18 months. That's well beyond the six weeks that a single dose of the antiviral drug, nivirapine, is given to a newborn to reduce the risk that the baby will contract HIV from his or her infected mother.

But in a study that observers say could revise recommendations for breastfeeding in HIV positive women, researchers in Malawi tested a combination of nivirapine and the antiretroviral drug AZT for 14 weeks.

Ten percent of infants who received the standard of care - a dose of nivirapine and AZT for one week - became infected with HIV after 14 weeks, compared to five to six percent of infants whose extended regimens of nivirapine and AZT.

Taha Taha is with Johns Hopkins University's Bloomberg School of Public Health in Maryland and is a co-author of the study.

Taha says both drugs, which are inexpensive and readily available, could make a significant impact on HIV transmission.

"About half a million infants are being infected every year and most of these are in Africa," said Taha Taha. "And you can just see the magnitude of the savings that can be made."

In an editorial in the Journal, the director of the pediatric research unit at South Africa's Witswatersrand University, Glenda Gray, says the study also showed antiviral treatment had to continue beyond 14 weeks, or the mothers had to stop breastfeeding, to protect their babies.

In a second study, researchers found that there was no difference in survival of uninfected infants who were weaned at four months compared to those who were breastfed indefinitely by their HIV infected mothers.

Oddly, the researchers also found that HIV infected babies who stopped feeding early died sooner than those who continued to breastfeed.

Gray says the paradoxical finding puts women in a bind.

"If they continued to breastfeed their babies, their babies may survive but their babies may become HIV infected," said Glenda Gray. "If they stop breastfeeding their babies, their babies may not be infected but they may die from diarrheal diseases. Or if you stop breastfeeding and your baby is already infected, you may cause your baby to die quicker."

Gray says the results of both studies are likely to prompt a discussion of mother-to-infant transmission of HIV.