1. Division of Infectious Diseases, Department of Internal Medicine, Chungbuk National University Hospital, Cheongju, Korea.
2. Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea.
3. Division of Infectious Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
4. AIDS research Institute, Yonsei University College of Medicine, Seoul, Korea.
5. Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
6. Division of Infectious Diseases, Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
7. Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
8. Department of Preventive Medicine, Hanyang University College of Medicine, Seoul, Korea.