A measles exposure warning has been issued for people who flew on a number of WestJet and Emirates flights between March 19 and March 24.

WestJet says a flight crew member was recently diagnosed with the measles virus and may have exposed passengers to the illness on several flights.

In a statement Friday, the airline said staff have begun contacting guests from the affected flights to let them know of the possible exposure.

The following flights are affected:

March 22 – WS450 Abbotsford to Calgary.

March 22 – WS610 Calgary to Ottawa.

March 22 – WS369 Ottawa to Toronto.

March 23 – WS590 Toronto to Montreal.

March 24 – WS581 Montreal to Toronto.

March 24 – WS2668 Toronto to Providenciales, Turks and Caicos.

March 24 – WS2669 Providenciales, Turks and Caicos to Toronto.

Anyone on these flights who develops a fever or cold-like symptoms should contact a doctor.

On Thursday, The Toronto Health Department issued a health warning, saying it was investigating three confirmed cases of the measles in the city.

Emirates also affected

WestJet spokesperson Lauren Steward said the airline is working with the Toronto health department and "health and safety is our top priority."

In addition, the Toronto Health Department listed two overseas Emirates Airlines flights where people may have been exposed to the illness in March.

They included: Emirates flight EK517, which departed Delhi, India March 19, at 4:12 p.m. and arrived in Dubai, U.A.E., at 6:13 p.m., and Emirates flight EK241, which departed Dubai, U.A.E. on March 20 at 9:55 a.m. and arrived in Toronto at 4:04 p.m. ET.

Health officials say measles is a highly contagious disease that spreads easily to those who are vulnerable and not immune.

Anyone on these flights who has not had two doses of a measles vaccine or who has not had measles in the past could be at risk of infection, the news release said.