Background:  Recent evidence from clinical trials in Africa suggests high morbidity from diarrhea among infants who are weaned at 6 months of life. We describe diarrhea among uninfected infants of HIV-infected mothers enrolled in the Breastfeeding Antiretrovirals Nutrition (BAN) Study currently ongoing in Lilongwe, Malawi.

Methods:  BAN is a randomized, controlled clinical trial of an ART and a nutritional intervention among breastfeeding HIV-infected mothers with CD4⁺ cell counts >200/mm³ and their infants. Mothers are counselled to exclusively breastfeed followed by rapid weaning by 28 weeks. Mothers and infants are randomized to a maternal or an infant ART regimen or to standard of care during breastfeeding. In addition, mothers are randomized to receive or not a nutritional supplement during breastfeeding. We examined the rates of infant diarrhea and of hospitalization and death due to diarrhea in HIV-uninfected infants enrolled in the BAN trial to-date. We compared these rates with national Malawi data in infants who follow local feeding practices of extended breastfeeding into the second year of life.

Results:  Between April 2004 and June 2006, 771 HIV-uninfected infants had been enrolled in BAN, of whom 225 uninfected infants had reached 28 weeks of age. Figure1 shows the proportion of infants with diarrhea during the first year of life. There was an increase around the time of weaning that continued through the end of the first year of life. Hospitalizations due to diarrhea also peaked around the time of weaning (Figure 2). The frequency of diarrhea was consistent with rates published in the literature. There was a higher probability of infant diarrhea in the rainy, compared with the non-rainy season (p <0.001). The overall HIV-uninfected infant mortality (43/1000) was much lower than that reported in the Malawi Demographic and Health Survey (76/1000 live births).

Conclusions:  We observed an increase in diarrhea during and following weaning among exclusively breastfed infants reportedly weaned at 6 months. This is consistent with the pattern seen in populations who practice prolonged breastfeeding, as this time coincides with the introduction of complementary infant foods. Greater emphasis should be placed on hygienic preparation of weaning foods and water purification in order to decrease infant diarrheal morbidity in resource-limited settings.

Figure 1                                                            Figure 2