Should HIV-positive mothers living in underdeveloped countries choose optimal nutrition for their infants by breastfeeding? Or should they risk malnutrition to minimize HIV transmission? Two recent studies offer renewed support for breastfeeding in "low-resource" areas.

In one study, Kumwenda and colleagues examined three groups of infants born to 3,016 breastfeeding HIV-positive women in Malawi who were treated prophylactically with antiretroviral drugs: the control group received a single dose of nevirapine plus zidovudine for the standard one-week treatment period, and the other two groups received the control regimen for the standard week and further antiretroviral therapy for 14 weeks, one group with nevirapine and the other with nevirapine and zidovudine. After nine months, the two groups on the extended regimen had significantly lower rates of postnatal HIV-1 infection (5.2% and 6.4% in the single- and dual-prophylaxis groups, respectively) than the control group (10.6%).

In the second study, Kuhn and colleagues recruited 958 HIV-positive mothers in Zambia to determine whether the recommended practice of early weaning helps reduce postnatal HIV transmission. One group (n = 481) was encouraged to wean their infants abruptly at four months; 69% stopped within five months, most within two days of beginning weaning. The other group (n = 477) was encouraged to breastfeed as long as they wanted; the median duration was 16 months. No significant differences in HIV-free survival at 24 months were found between the two groups (68% and 64%, respectively), suggesting no benefit in early weaning.

These results support efforts to develop guidelines for this region. Marie-Louise Newell and Ruth Bland at the Africa Centre for Health and Population Studies in Somkhele, South Africa, whose work focuses on reducing vertical transmission of HIV, say the two studies underscore the belief that the odds favor breastfeeding for HIV-positive mothers who otherwise would have no choice but to put their infants at risk for malnutrition or infection from contaminated water or bottles.

Dlamini feeds her two-month-old baby Banele a bottle of formula at their home in Soweto, South Africa, on March 8. New U.S. funded studies indicate that the risk of a baby contracting HIV through breast milk is lower than the health risks of being denied its nutritional and protective benefits, particularly in poor countries where mothers don't have sure access to clean water with which to prepare formula.

"Here, in the first six months of life, the 4% to 5% transmission rate associated with HIV isn't that high compared with the 8% to 9% of children dying of diarrhea and pneumonia, irrespective of HIV," says Bland. But in countries where infant mortality rates are low, the balance would favor avoidance of breastfeeding.

Denese Gomes, an NP at the Infectious Disease Clinic at Virginia Commonwealth University Medical Center in Richmond, puts these findings into context when discussing mothers in developed countries. In the United States, she says, "even if an HIV-positive woman has an undetectable viral load at the time of delivery, we don't advocate breastfeeding. We have every resource in this country to provide adequate and safe nutrition, so the risks of getting HIV far outweigh the danger" of malnutrition or other infection.

Ultimately, says Bland, "there is no blanket policy for everyone." Clinicians tailoring recommendations must take into account the potential for drug resistance in both mother and infant, their access to medical care, and social norms.