1. Department of Population Medicine, University of Guelph, Guelph, Ontario, Canada.
2. Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, Guelph, Ontario, Canada.
3. Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, Lethbridge, Alberta, Canada.
4. Public Health Consultant, Stratford, Ontario, Canada.
5. Perth District Health Unit, Stratford, Ontario, Canada.
6. Wellington-Dufferin-Guelph District Health Unit, Guelph, Ontario, Canada.
7. Public Health Ontario, Toronto, Ontario, Canada.
8. Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.