1. Department of Medical Microbiology and Immunology, University of Alberta
2. Department of Microbiology, Montreal Children's Hospital, Montreal
3. Laboratoire de santé publique du Québec, Sainte-Anne-de-Bellevue
4. Institut National de Santé Publique du Québec, Québec, Québec, Canada
5. Microbiology and Public Health, Edmonton, Alberta