Arif Ismail1, Wayne L Gold2. 1. Division of Infectious Diseases, Department of Medicine (Ismail), University of Alberta, Edmonton, Alta; Division of Infectious Diseases, Department of Medicine (Gold), University of Toronto, Toronto, Ont. 2. Division of Infectious Diseases, Department of Medicine (Ismail), University of Alberta, Edmonton, Alta; Division of Infectious Diseases, Department of Medicine (Gold), University of Toronto, Toronto, Ont. wayne.gold@uhn.ca.