1. Toho University, Tokyo, Japan
2. Tokyo Medical University Hospital, Tokyo, Japan
3. Saitama Medical Centre, Saitama, Japan
4. Sakura Medical Centre, Toho University, Chiba, Japan
5. Tokyo Medical and Dental University Hospital, Tokyo, Japan
6. Miroku Medical Laboratory Co. Ltd., Nagano, Japan
7. International University of Health and Welfare, Chiba, Japan
8. National Institute of Infectious Diseases, Tokyo, Japan