1. Department of Medicine, Dalhousie University, Halifax, NS, Canada
2. The Division of Diagnostic and Applied Microbiology, Department of Laboratory Medicine and Pathology, University of Alberta and The Provincial Laboratory for Public Health, Edmonton, AB, Canada
3. Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
4. School of Public Health, University of Alberta, Edmonton, AB, Canada