1. Health and Environment Research Institute of Gwangju Metropolitan City, Gwangju, South Korea.
2. Premedical Science, College of Medicine, Chosun University, Gwangju, South Korea.
3. Department of Internal Medicine, College of Medicine, Chosun University, Gwangju, South Korea.
4. Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.