As a new measure to curb flights to Canada with COVID-19 cases on board, the federal government now requires all international passengers to provide a negative test result within 72 hours of their flight.

However, it seems that cases are still slipping through the cracks, as Health Canada says that all passengers on two recent flights to Montreal may have been exposed.

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TS663, TS665 Air Transat flights with "all rows" affected

Both flights were departing from Port-au-Prince, Haiti. According to Health Canada, passengers in "all rows" may have been exposed to the disease.

The first flight was on January 10 and the second was on January 13.

"There are groups of people who have been granted an extraordinary temporary exemption [from requiring a negative test], due to lack of testing capacity or availability," said Debbie Cabana, director of marketing at Air Transat, to Narcity.

"This is particularly the case for passengers from Haiti."

"If there are passengers who have travelled have tested positive for Covid-19, this can only be identified after they have left the plane upon arrival in Canada, for example through a test at the airport."

"We would therefore only be informed at a subsequent time by public health authorities in this case."