1. Department of Microbiology, Cancer Research Institute, Institute of Endemic Diseases, SNUMRC
2. Division of Epidemic Intelligence Service, Korean Center for Disease Control and Prevention, Seoul 122-701, Korea
3. Department of Internal Medicine, Gachon University Gil Medical Center, Icheon 405-760
4. Department of Preventive Medicine
5. Department of Laboratory Medicine
6. Seoul National University College of Medicine, and Clinical Research Institute, Seoul National University Hospital, Seoul 110-799