HIV-Positive Mothers in Resource-Poor Settings Can Safely Use Formula as Alternative to Breastfeeding, Study Says
Mortality and morbidity rates are similar for breastfed and formula-fed children of HIV-positive mothers, indicating that formula feeding can be a "safe alternative" to breastfeeding in resource-poor settings as long as women are properly educated and clean water exists, according to a study in today's Journal of the American Medical Association (Mbori-Ngacha et al., JAMA, 11/21). The study, conducted by researchers from the University of Nairobi and the University of Washington between 1992 and 1998 at four Nairobi antenatal clinics, is a companion to a larger study on the risk of HIV transmission through breast milk ( Reuters/New York Times, 11/21). Dorothy Mbori-Ngacha and colleagues evaluated 371 live-born singleton or first-born twin infants. Their mothers were randomly assigned to use formula (n=186) or to breastfeed (n=185). The researchers compared gestational age, sex and morbidity at birth among infants in both groups.
After following the infants for two years, mortality rates were found to be similar between the groups (20.0% for formula-feeding versus 24.4% for breastfeeding) even after adjusting for HIV status. Among infants who remained HIV-negative after two years, the mortality rate was 10.0% in the formula group and 8.1% in the breastfeeding group. HIV infection, however, was associated with a nine-fold increase in mortality risk. One hundred thirty-eight infants died during follow-up (58 in the formula group, 80 in the breastfeeding group). Pneumonia was the leading cause of death (53%), followed by diarrhea (39%) and sepsis (10%). Among morbidity indicators, diarrhea incidence was "almost identical" over two years for the formula and breastfeeding groups (155 versus 149 per 100 person-years) and the incidence of pneumonia was identical in both groups (62 per 100 person-years). However, after adjusting for HIV status, children who were breastfed had significantly better nutritional status over two years than those who received formula.
Many health advocates have advocated breastfeeding over formula feeding in resource-poor settings, even with the risk of HIV transmission, because of the "possibility that breast milk avoidance would be accompanied by an increase in mortality that might offset any gains achieved by decreasing HIV transmission." However, the authors note that with "adequate" supplies of formula and nutritional counseling, the women participating in the trial were able to administer formula feeding "without seriously compromising the nutritional status of their infants." They add that the "magnitude of risks" associated with formula feeding will vary depending on the availability of such education, access to medical care and clean water. "Because of these differences, we would advocate context-specific counseling for HIV-infected expectant mothers so that each woman can select the feeding method that maximizes benefits and minimizes risks given her individual situation," the researchers conclude (Mbori-Ngacha et al., JAMA, 11/21). In an accompanying editorial, however, Drs. Laura Guay and Andrea Ruff of Johns Hopkins University state that there are several problems with the study's recommendations. Many women in resource-poor countries do not know their HIV status. Testing is sometimes not available or "unacceptable" to many women. They also note that the kind of counseling that would be required to ensure that formula-fed infants get the nutrition that they need is "difficult in the context of brief visits in overcrowded antenatal clinics and limited postpartum maternal and infant care." Guay and Ruff state that the type of health infrastructure required to reduce the risks associated with formula feeding is not found in most sub-Saharan African countries. They agree, however, that more should be done to reduce HIV transmission through breastfeeding and suggest further investigations into early weaning and avoidance of nursing during periods of breast inflammation. Antiretroviral prophylaxis is also one strategy that should be investigated further, Guay and Ruff add. "The issue of HIV and breastfeeding cannot be separated from the global reality of increasing malnutrition and mortality rates among children in many sub-Saharan African countries. That breastfeeding with all its benefits should also pose a significant risk of HIV transmission is one of the ultimate public health paradoxes and will likely continue to be a major challenge for the prevention of HIV infections in infants living in resource-poor settings," they conclude (Guay/Ruff, JAMA, 11/21).