1. The Thai Red Cross AIDS Research Centre, Bangkok 10330, Thailand
2. Global AIDS Program, Thailand MOPHU. S. CDC Collaboration, Nonthaburi 11000, Thailand
3. Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10400, Thailand
4. Maternal and Child Health Group, Bureau of Health Promotion, Department of Health, Ministry of Public Health, Nonthaburi 11000, Thailand
5. Benjalak Hospital, Srisaket 33110, Thailand; fNakornping Hospital, Chiang Mai 50180, Thailand
6. Nakornping Hospital, Chiang Mai 50180, Thailand
7. Bamrasnaradura Infectious Disease Institute, Ministry of Public Health, Nonthaburi 11000, Thailand
8. Bureau of AIDS, TB, and STIs, Department of Disease Control, Ministry of Public Health, Nonthaburi 11000, Thailand
9. World Health Organization, Thailand Office, Bangkok 11000; jThai AIDS Society, Bangkok 10330, Thailand