1. Department of Pediatrics, Bronx Lebanon Hospital Center, Bronx, New York
2. Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts
3. Department of Pediatrics, Jacobi Medical Center and Albert Einstein College of Medicine, Bronx, New York
4. Department of Pediatrics, State University of New York Health Science Center, Stony Brook, New York
5. Pediatric, Adolescent, and Maternal AIDS Branch, National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland
6. Division of AIDS, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
7. Division of Infectious Diseases, Children's Memorial Hospital and Northwestern University School of Medicine, Chicago, Illinois
8. Division of Infectious Diseases, Children's Hospital and Harvard Medical School, Boston, Massachusetts
9. Department of Pediatrics, Boston Medical Center, Boston, Massachusetts