MONTREAL -- Three Air Transat employees -- two flight attendants and one pilot -- have tested positive for COVID-19, airline officials confirmed Wednesday.

“It is impossible to know with certainty what the source of contamination is, whether it was on a plane, at a stopover or in Canada,” said Christophe Hennebelle, vice-president of human resources and public affairs. “We currently have approximately 150 flight attendants and 30 pilots in quarantine.”

Hennebelle tells CTV News two of the employees are from Quebec and one is from Ontario.

“Whenever we have suspected or confirmed cases, amongst our employees or clients, we immediately inform the public health agencies who, in turn, contact people who might have been in contact with them,” he said.

Hennebelle notes the airline previously had 300 flight attendants in quarantine.

He explains when there is a suspected case of the virus on a flight, all employees are immediately isolated.

“The vast majority of quarantines are due to possible exposure on board, but there are, of course, also other sources, such as returning from vacation,” he added, noting employees are aware of the proper hygiene protocols they need to follow when working. “We are infinitely grateful to our crews who are exposed on a daily basis as they do their jobs to bring all Canadians home,” Hennebelle said. “Their dedication is exemplary.”

In response to the COVID-19 pandemic, all Air Transat flights will be suspended as of April 1.

Monday, the company announced it would also be temporarily laying off 70 per cent of its workforce in Canada.

The decision was made as non-essential travel around the world comes to a standstill as countries closed their borders in an effort to slow the spread of the virus.