1. Okinawa Prefectural Institute of Health and Environment; 2085 Ozato Nanjo-Shi Okinawa 901-1202
2. Gunma Prefectural Institute of Public Health and Environmental Sciences; 378 Kamioki-Machi Maebashi-shi Gunma 371-0052
3. Department of Virology II
4. Infectious Disease Surveillance Center; National Institute of Infectious Diseases; 4-7-1 Gakuen Musashimurayama-Shi Tokyo 208-0011 Japan