1. Division of Infectious Diseases, Department of Internal Medicine, Soonchunhyang University Cheonan Hospital, Cheonan, Korea
2. Division of Infectious Diseases, Department of Internal Medicine, Soonchunhyang University Seoul Hospital, Seoul, Korea
3. Department of Nursing, College of Medicine, Soonchunhyang University, Cheonan, Korea
4. Division of Respiratory Medicine, Department of Internal Medicine, Soonchunhyang University Seoul Hospital, Seoul, Korea