1. Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
2. International Health Policy Program, Nonthaburi, Thailand
3. Division of Infectious Diseases, Department of Medicine, David Geffen School of Medicine at the University of California, Los Angeles, California, USA
4. Siriraj Institute of Clinical Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand