1. IWK Health Centre, and
2. Departments ofMicrobiology and Immunology, and
3. Pathology, Dalhousie University, Halifax, NS;
4. Division of Hematology, Brigham and Women's Hospital and
5. Division of Hematology-Oncology, Children's Hospital Boston, Harvard Medical School, Boston, MA; and
6. Department of Pediatrics, Dalhousie University, Halifax, NS