WestJet is warning passengers from some March flights, including to and from Calgary, may have been exposed to measles.

Toronto Public Health has reported three lab-confirmed cases of the disease, one of which is a WestJet flight crew member.

Of the seven WestJet flights where passengers may have been exposed, two involve Calgary.

Both were on March 22, one in the early morning coming in from Abbotsford B.C., the other late in the morning outbound to Ottawa:

March 22

WestJet flight WS450, departed Abbottsford, B.C. at 5:49 a.m. and arrived in Calgary at 7:50 a.m.

WestJet flight WS610, departed Calgary at 10:15 a.m. and arrived in Ottawa at 3:47 p.m.

WestJet flight WS369, departed Ottawa at 4:40 p.m. and arrived in Toronto at 5:42 p.m.

March 23

WestJet flight WS590, departed Toronto at 4:27 p.m. and arrived in Montreal at 5:41 p.m.

March 24

WestJet flight WS581, departed Montreal at 7:55 a.m. and arrived in Toronto at 9:13 a.m.

WestJet flight WS2668, departed Toronto at 10:16 a.m. and arrived in Turks and Caicos Islands at 1:56 p.m.

WestJet flight WS2669, departed Turks and Caicos Islands at 2:59 p.m. and arrived in Toronto at 7:15 p.m.

The airline says it’s working very closely with Toronto Public Health and they’ve already started contacting passengers.

Measles is a highly contagious disease that spreads easily to those who are not immune or are vulnerable. Anyone who has not had two doses of a measles vaccine (MMR or MMRV) or who has not had measles in the past is at risk of infection. Infants under one year of age, pregnant women and people with weakened immune systems can get very ill with measles.