1. Fukuoka Prefectural Chuo Livestock Hygiene Service Center , Fukuoka, Japan
2. Fukuoka Prefectural Hokubu Livestock Hygiene Service Center , Kama, Fukuoka, Japan
3. National Institute of Animal Health, National Agriculture and Food Research Organization (NARO) , Tsukuba , Ibaraki, Japan
4. Hokkaido Research station, National Institute of Animal Health, National Agriculture and Food Research Organization (NARO) , Sapporo, Hokkaido, Japan