[1] Univ Minnesota, Coll Vet Med, Vet Populat Med Dept, Hlth Div 1, St Paul, MN 55108 USA
[2] Univ Minnesota, Coll Vet Med, Vet Populat Med Dept, Ctr Anim Hlth & Food Safety, St Paul, MN 55108 USA
[3] Univ Surrey, Sch Vet Med, Dept Vet Epidemiol & Publ Hlth, Guildford, Surrey, England
[4] City Minneapolis Hlth Dept, Food Lodging & Pools, Minneapolis, MN USA
[5] WHO, Dept Country Hlth Emergency Preparedness & IHR, Hlth Country Operat Team 1, Geneva, Switzerland
[6] Univ Minnesota, Sch Publ Hlth, Environm Hlth Sci, Minneapolis, MN USA