1. Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
2. Division of Infectious Diseases, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
3. Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
4. Infection Control Team, Chung-Ang University Hospital, Seoul, Korea
5. Department of Infection Control, Ewha Womans University Mokdong Hospital, Seoul, Korea
6. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
7. Division of Infectious Diseases, Kyung Hee University College of Medicine, Seoul, Korea