1. Graduate Studies, Faculty of Allied Health Sciences, Thammasat University, Rangsit Center, Pathum-thani, Thailand
2. Department of Parasitology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
3. Department of Pediatrics, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
4. Department of Otorhinolaryngology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
5. Department of Social Medicine and Environment, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand