1. a Children's Memorial Hospital, Feinberg School of Medicine , Northwestern University , Chicago , USA
2. b Department of Epidemiology, Harvard School of Public Health , Harvard University , Boston , USA
3. c Center for Biostatistics in AIDS Research, Harvard School of Public Health , Harvard University , Boston , USA
4. d Eunice Kennedy Shriver National Institute of Child Health and Human Development , National Institutes of Health , Bethesda , USA
5. e Department of Biostatistics, Harvard School of Public Health , Harvard University , Boston , USA
6. f Department of Pediatrics , University of Illinois , Chicago , USA
7. g Center for Mental Health Research on AIDS , National Institute of Mental Health , Bethesda , USA
8. h St. Jude Children's Research Hospital , Memphis , USA
9. i Departments of Psychiatry and Otolaryngology and Communication Disorders , Children's Hospital , Boston , USA
10. j Neurosciences Department , University of California , San Diego , USA
11. k Department of Infectious Diseases , Tulane University Health Sciences Center , New Orleans , USA
12. l Department of Psychiatry and Sociomedical Sciences , Columbia University , New York , USA