1. Department of Microbiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
2. Department of Laboratory Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
3. Department of Internal Medicine, Catholic University of Korea, Kangnam St. Mary's Hospital, Seoul, Korea.
4. Department of Internal Medicine, Gyeongsang National University School of Medicine, Jinju, Korea.
5. Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
6. Division of Infectious Diseases, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.