1. Department of Preventive Medicine/Institute of Community Health, Hanyang University, College of Medicine, Seoul, Korea.
2. Department of Preventive Medicine, Eulji University, School of Medicine, Daejeon, Korea.
3. Division of Public Health Crisis Response, Korea Centers for Disease Control and Prevention, Cheongwon, Korea.
4. Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea.
5. Department of Pediatrics, The Catholic University of Korea College of Medicine, Seoul, Korea.
6. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea.
7. Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea.
8. Department of Pediatrics, Inha University School of Medicine, Incheon, Korea.
9. Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea.
10. Department of Pediatrics, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea.
11. Department of Pediatrics, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Korea.
12. Angel Internal Medicine Clinic, Daejeon, Korea.
13. Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
14. Department of Pediatrics, Soonchunhyang University College of Medicine, Cheonan, Korea.
15. Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea.
16. Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
17. Department of Internal Medicine, Chonbuk National Unversity Medical School and Hospital, Jeonju, Korea.
18. Department of Pediatrics, Chonbuk National Unversity Medical School and Hospital, Jeonju, Korea.
19. Department of Internal Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.