1. Microbiology and Infectious Diseases,
2. Department of Medicine,
3. University of Calgary, Calgary, Alberta;
4. From the Departments of Pediatrics and
5. Alberta Children's Hospital,
6. Department of Microbiology, Mount Sinai Hospital and the Toronto Medical Laboratories, University of Toronto, Toronto, Ontario.
7. Childhood and Vaccine Preventable Diseases Epidemiology Section, Division of Bacterial and Mycotic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia; and