[1] NIAID, Virol Lab, Div Intramural Res, Natl Inst Hlth NID,RML, Hamilton, MT 59840 USA
[2] Publ Hlth Agcy Canada, Natl Microbiol Lab, Winnipeg, MB, Canada
[3] Univ Tokyo, Inst Med Sci, Int Res Ctr Infect Dis, Dept Special Pathogens, Tokyo 1138654, Japan
[4] Univ Manitoba, Dept Med Microbiol, Winnipeg, MB, Canada
[5] NIAID, Rocky Mt Vet Branch, NIH, Hamilton, MT 59840 USA
[6] NIAID, RML Res Technol Sect, Div Intramural Res, NIH, Hamilton, MT 59840 USA
[7] Univ Tokyo, Inst Med Sci, Dept Microbiol & Immunol, Div Virol, Tokyo 1138654, Japan
[8] Univ Wisconsin, Sch Vet Med, Dept Pathobiol Sci, Madison, WI 53706 USA