Elevations in Mortality Associated with Weaning Persist into the Second Year of Life among Uninfected Children Born to HIV-Infected Mothers

BACKGROUND: Early weaning has been recommended to reduce postnatal human immunodeficiency virus (HIV) transmission. We evaluated the safety of stopping breast-feeding at different ages for mortality of uninfected children born to HIV-infected mothers. METHODS: During a trial of early weaning 958 HIV-infected mothers and their infants were recruited and followed up from birth to 24 months postpartum in Lusaka Zambia. One-half of the cohort was randomized to wean abruptly at 4 months and the other half of the cohort was randomized to continue breast-feeding. We examined associations between uninfected child mortality and actual breast-feeding duration and investigated possible confounding and effect modification. RESULTS: The mortality rate among 749 uninfected children was 9.4% by 12 months of age and 13.6% by 24 months of age. Weaning during the interval encouraged by the protocol (4-5 months of age) was associated with a 2.03-fold increased risk of mortality (95% confidence interval [CI] 1.13-3.65) weaning at 6-11 months of age was associated with a 3.54-fold increase (95% CI 1.68-7.46) and weaning at 12-18 months of age was associated with a 4.22-fold increase (95% CI 1.59-11.24). Significant effect modification was detected such that risks associated with weaning were stronger among infants born to mothers with higher CD4(+) cell counts (>350 cells/microL). CONCLUSION: Shortening the normal duration of breast-feeding for uninfected children born to HIV-infected mothers living in low-resource settings is associated with significant increases in mortality extending into the second year of life. Intensive nutritional and counseling interventions reduce but do not eliminate this excess mortality.