1. Division of Infectious Diseases, Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
2. Canadian Blood Services, Ottawa, Ontario, Canada
3. School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ontario, Canada
4. School of Public Health, University of Alberta, Edmonton, Alberta, Canada
5. Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada