Both patients recently travelled to Toronto from Wuhan, China, which is believed to be the epicentre of the outbreak.

Passengers who travelled on flight CZ3028 and 377 are urged to get checked out.

China's biggest airline said Thursday it's buying 110 Boeing 737 jets in a deal worth about $10 billion that comes just weeks after the U.S. plane maker said it's building a Chinese finishing plant for the aircraft type.