1. Division of Infectious Diseases, Department of Internal Medicine, Seoul Medical Center, Seoul, Korea
2. Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
3. Division of Infectious Diseases, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
4. Division of Infectious Diseases, Department of Internal Medicine, Inje University Ilsan Paik Hospital, Goyang, Korea