1. Umphang Hospital, Tak, Thailand;
2. Department of Paediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand;
3. Division of Epidemiology, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand;
4. Department of Sciences, Mahidol University International College, Nakhon Pathom, Thailand;
5. Siriraj Institute of Clinical Research, Mahidol University, Thailand