1. †Department of Medical Microbiology, University of British Columbia
2. *Division of Laboratories, British Columbia Centre for Disease Control, National Reference Service for Parasitology (Morphology), P.O. Box 34020, Postal Station D, Vancouver, British Columbia V6J 4M3, Canada
3. ‡Tropical Disease Unit, Toronto General Hospital, 200 Elizabeth Street, Toronto, Ontario M5G 2C4, Canada, and Departments of Medicine and Medical Microbiology, University of Toronto, Ontario, Canada