Public Health officials in Ontario are investigating a confirmed case of measles on an Air Canada flight from Switzerland.

Toronto Public Health that the person infected with the latest case of lab-confirmed measles was on Air Canada flight AC 0879 earlier this month. The direct flight departed at 9:25 a.m. from Zurich Airport in the country鈥檚 largest city and landed at Toronto Pearson International Airport around noon on March 6.

鈥淢ost people here are not at risk,鈥� assured Dr. Rita Shahin, associate medical officer of health, in an interview with CTVNews.ca. 鈥淢easles is quite rare in Ontario and all of Canada because people are appropriately vaccinated. But we do occasionally get imported cases.鈥�

Coincidentally, this latest case is the second such measles incident involving possible exposure on an Air Canada flight from Switzerland in a matter of weeks. Last month, officials confirmed that an infant in Brampton was infected after recent international travel. Measles is uncommon in both Canada and Switzerland, but remains an issue is other countries such as the Philippines and India.

While there is no risk to the general public or those who simply visited either airport, said Shahin, those who were on the flight in question may have cause for concern if they fall into certain vulnerable categories. Infants under the age of 1 who would not have any doses of the measles vaccine (MMR or MMRV), people with compromised immune systems from existing illnesses such as cancer, and pregnant women who are not vaccinated are among the most at-risk people.

Those on a flight with a measles-infected person are at greater risk than those who simply visited the same airport because in the confined spaces of an airplane the air is often re-circulated throughout the cabin, which means the virus can be more easily transmitted.

鈥淚t鈥檚 airborne. It can be exposed by someone who鈥檚 coughing or sneezing,鈥� said Shahin, stressing that those who were on the flight and not properly immunized should check their vaccine status and consult their physician ahead of any clinic visits if they are concerned.

But the rest of us can rest easy, she said. 鈥淭he risk to most people is going to be non-existent if they鈥檙e properly immunized.