1. Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima-shi, Kagoshima 890-0065, Japan
2. Shiga Prefectural Institute of Public Health, 13-45 Gotenhama, Otsu-shi, Shiga 520-0834, Japan
3. Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, 5200 Kihara, Kiyotake-cho, Miyazaki 889-1692, Japan
4. Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, 1-1, Gakuenkibanadainishi, Miyazaki-shi, Miyazaki 889-2192, Japan