1. Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan
2. Management Department of Biosafety, Laboratory Animal, and Pathogen Bank, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan
3. Department of Veterinary Science, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan
4. Joint Graduate School of Veterinary Medicine, Yamaguchi University, Yamaguchi City, Yamaguchi 753-8515, Japan
5. Department of Virology II, National Institute of Infectious Diseases, Musashimurayama City, Tokyo 208-0011, Japan
6. Faculty of Veterinary Medicine, Okayama University of Science, Imabari City, Ehime 794-8555, Japan