1. Chiba Prefectural Chuou Livestock Hygiene Service Office, Chiba, Japan
2. Fukushima Prefectural Chuou Livestock Hygiene Service Center, Fukushima, Japan
3. Division of Transboundary Animal Diseases, National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Tokyo, Japan
4. Division of Zoonosis Research, National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Ibaraki, Japan
5. Division of Hygiene Management Research, National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Ibaraki, Japan