1. Department of Otolaryngology, Taichung Veterans General Hospital, Department of Medicine, Chung-Shan Medical University, Taichung, Taiwan, Republic of China
2. Department of Otolaryngology, Chung-Shan Medical University Hospital, Department of Medicine, Chung-Shan Medical University, Taichung, Taiwan, Republic of China
3. Department of Otolaryngology, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China
4. Department of Clinical Microbiology, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China