HIV Exposure and Formula Feeding Predict Under-2 Mortality in HIV-Uninfected Children, Botswana

Objectives: To prospectively assess rates and detailed predictors of morbidity and mortality among HIV-exposed uninfected children and HIV-unexposed children in Botswana in a more recent era.

Study design: We enrolled HIV-infected and HIV-uninfected mothers and their children in the prospective observational Tshipidi study at 2 sites (1 city and 1 village) in Botswana from May 2010-July 2012. Live-born children and their mothers were followed for 24 months postpartum. Detailed sociodemographic data, health, and psychosocial characteristics were collected at baseline and prospectively, and health outcomes ascertained. Mothers chose infant feeding method with counselling.

Results: A total of 893 live-born HIV-uninfected children (436 HIV-exposed uninfected, 457 HIV-unexposed) were followed. HIV-infected mothers had a median CD4 count of 410 cells/mm³, 32% took 3-drug antiretroviral treatment during pregnancy, 67% took only zidovudine, and 1% took <2 weeks of any antiretrovirals antepartum. Twenty four-month vital status was available for 888 (99.4%) children. HIV-exposed uninfected children had a significantly higher risk of death compared with children of HIV-uninfected mothers (5.0% vs 1.8%) (adjusted hazard ratio 3.27, 95% CI 1.44-7.40). High collinearity between maternal HIV status and child feeding method precluded analysis of these factors as independent predictors of mortality. Preterm birth, low birth weight, and congenital anomaly were also associated with mortality (in separate analyses), but maternal socioeconomic factors, depression, substance use, and social support were not significant predictors.

Conclusions: The strongest predictors of 24-month mortality among children in Botswana were HIV exposure and formula feeding, although the relative contribution of these factors to child health could not be separated.