1. From the University of Toronto, Mount Sinai Hospital, Sunnybrook Health Sciences Centre, St. Joseph's Health Centre, The Scarborough Hospital, and Humber River Regional Hospital, Toronto, Ontario, Canada; Centers for Disease Control and Prevention, Atlanta, Georgia; The Ottawa Hospital, Ottawa, Ontario, Canada; National Centre for Streptococcus, Edmonton, Alberta, Canada; Hamilton Health Sciences, Hamilton, Ontario, Canada; and Grand River Hospital, Waterloo, Ontario, Canada.