1. HIV-NAT, Thai Red Cross AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
2. SEARCH, Thai Red Cross AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
3. Department of Medicine, Faculty of Medicine, Chulalongkorn University, Rama IV Rd, Pathumwan, Bangkok 10330, Thailand
4. Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Rama IV Rd, Pathumwan, Bangkok 10330, Thailand
5. Prevention Unit, Thai Red Cross AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand