[1] Hokkaido Univ, Fac Vet Med, Dept Dis Control, Lab Microbiol,Kita Ku, Kita 18,Nishi 9, Sapporo, Hokkaido 0600818, Japan
[2] Hokkaido Univ, Res Ctr Zoonosis Control, Unit Risk Anal & Management, Kita Ku, Kita 20,Nishi 10, Sapporo, Hokkaido 0010020, Japan
[3] Hokkaido Univ, Res Ctr Zoonosis Control, Int Collaborat Unit, Kita Ku, Kita 20,Nishi 10, Sapporo, Hokkaido 0010020, Japan