1. Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee;
2. Westat, Rockville, Maryland;
3. Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia;
4. Department of Pediatrics, University of Miami, Miller School of Medicine, Miami, Florida;
5. Unidade de Pesquisa Materno Infantil, Policlinica Santa Clara, Maternidade, Hospital dos Servidores do Estado, Rio de Janeiro, Brazil;
6. Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil;
7. Infectious Disease Department, Hospital Femina, Porto Alegre, Brazil;
8. Instituto de Medicina Tropical “Daniel Alcides Carrión”- Sección de Epidemiologia, University of San Marcos, Lima, Peru;
9. Servico de Doencas Infecciosas e Parasitarias, Irmandade de Santa Casa de Misericordia, Porto Alegre, Brazil; and
10. Pediatric, Adolescent and Maternal AIDS Branch, Center for Research for Mothers and Children, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland