1. Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea.
2. Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Konkuk University School of Medicine, Chungju, Korea.
5. Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
6. Gachon University Gil Hospital Cancer Center, Gachon University Gil Medical Center, Incheon, Korea.
7. Department of Pediatrics, Eulji University School of Medicine, Daejeon, Korea.
8. Department of Internal Medicine, Soonchunhyang University College of Medicine, Bucheon, Korea.
9. Infection Control Unit, Korea University Guro Hospital, Seoul, Korea.
10. Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
11. Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea.