1. Saga Prefectural Central Livestock Hygiene Service Center, 2-7-4 Wakakusu, Saga, Saga 849-0928, Japan
2. National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan
3. Tochigi Prefecture Kenou Livestock Hygiene Service Center, 6-8 Hiraidekougyoudanchi, Utsunomiya, Tochigi 321-0905, Japan