[1] Univ Toronto, Hosp Sick Children, Res Inst, Div Paediat Emergency Med, Toronto, ON M5G 1X8, Canada
[2] Univ Toronto, Hosp Sick Children, Res Inst, Div Infect Dis, Toronto, ON M5G 1X8, Canada
[3] Univ Toronto, Hosp Sick Children, Res Inst, Div Pediat Med, Toronto, ON M5G 1X8, Canada
[4] Univ Toronto, Hosp Sick Children, Res Inst, Dept Pediat, Toronto, ON M5G 1X8, Canada
[5] Univ Toronto, Hosp Sick Children, Res Inst, Dept Diagnost Imaging, Toronto, ON M5G 1X8, Canada
[6] Univ Toronto, Hosp Sick Children, Res Inst, Dept Populat Hlth Sci, Toronto, ON M5G 1X8, Canada