1. Division of Neonatology, Department of Pediatrics, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama;
2. Centre for Infectious Disease Research in Zambia, Lusaka, Zambia;
3. Department of Statistics and Epidemiology, RTI International, Durham, North Carolina;
4. Department of Paediatrics and Child Health, University Teaching Hospital, University of Zambia, Lusaka, Zambia;
5. Department of Child and Adolescent Health, World Health Organization Country Office in Hanoi, Socialist Republic of Viet Nam; and
6. Center for Research for Mothers and Children, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland