[1] Univ W Indies, Dept Microbiol, Kingston 7, Jamaica
[2] Univ Hlth Network, Dept Microbiol, Mt Sinai Hosp, Toronto, ON, Canada
[3] Univ Toronto, Dept Lab Med & Pathobiol, Toronto, ON, Canada
[4] Publ Hlth Agcy Canada, Natl Microbiol Lab, Winnipeg, MB, Canada