1. Division of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Dankook University College of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Gyeongsang National University School of Medicine, Jinju, Korea.
4. Division of Infectious Diseases, Department of Internal Medicine, Kandong Sacred Heart Hospital College of Medicine, Hallym University College of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Division of Allergy and Infectious Diseases, Cheongju St. Mary's Hospital, Cheonju, Korea.
6. Division of Infectious Diseases, Department of Internal Medicine, Soon Chun Hyang University Bucheon Hospital, Soon Chun Hyang University College of Medicine, Bucheon, Korea.
7. Department of Internal Medicine, Armed Forces Capital Hospital, Seoul, Korea.
8. Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.