Canadians desperate to return home from abroad in the face of the COVID-19 pandemic are easily circumventing air travel screening aimed at preventing sick and infected passengers from boarding planes, CBC News has found.

Some are simply hiding symptoms from officials to ensure they can get back home.

CBC News has found a number of instances where sick travellers have boarded airplanes back to Canada, no matter the risks of spreading infection.

"Now is just the worst time to be coughing, sneezing or reporting any kind of symptom at an airport," said one university student in Toronto, who flew home from Spain on March 14. She admitted she purposely hid her symptoms and the fact she'd been suffering a fever hours before boarding the flight.

"It wasn't information you volunteered. So I just stayed quiet about it."

CBC has agreed to withhold her name to shield her from backlash, given that she travelled two days before Prime Minister Justin Trudeau announced anyone with symptoms would be barred from boarding return flights. Further, she was only officially diagnosed with COVID-19 after she got home, and public health officials are now tracking all of her contacts.

WATCH | Canadian woman talks about decision to fly home despite feeling ill

Sick air travellers hide COVID 19 symptoms to board flights home. 6:35

She said she wasn't sick when she bought her ticket, but developed a fever the day before her flight and took precautions to wear a mask and gloves on the plane to prevent the spread of any illness.

Although she didn't technically flout the rule set out by the government, her experience reflects that of many Canadians stuck abroad during the pandemic.

"My priority was just being able to get on the first flight back to Canada. You know, no matter what the consequences were," she said, citing pressure from her university, the Canadian government and family, who all implored her to come home.

Her case demonstrates just how weak Canada's screening of air travellers is, given it relies solely on voluntary reporting of symptoms.

Even the "enhanced screening" adopted in recent days amounts to a simple series of health questions put to air travellers and does not involve any physical detection, testing or thermal screening now being used in many other countries.

Temptation 'to lie'

Jane Salhani of Aurora, Ont., which is north of Toronto, flew home from Munich on Sunday aboard an Air Canada flight where an obviously sick traveller had passengers and attendants on edge.

"This one woman, she was wearing a mask. She coughed the entire nine hours. I mean, everybody on that flight was extremely unnerved by it," Salhani told CBC News. (Disclosure: Salhani is related to one of the authors of this article.)

Some travellers who have come through Canadian airports like Toronto's Pearson International have observed that COVID-19 screening measures are more comprehensive in other countries. (Nathan Denette/The Canadian Press)

Salhani recalled airline officials asking passengers whether they felt ill or had fever before boarding, but figured it isn't terribly effective in keeping sick people off planes.

"I'm sure the temptation is there to lie, because you want to get home to your own health system ... if you're not feeling well, right? You don't want to be stuck in a foreign country," she said.

Now at home in self-isolation with her husband, Salhani wondered whether airline and public health officials will be in touch about potential exposure. She noted the sick passenger was taken aside and interviewed on arrival at Toronto's Pearson Airport, as all arriving passengers were handed pamphlets instructing them to self-isolate for 14 days.

"I'm sure we got on that plane healthy," Salhani said. "I'm not sure we got off that plane healthy."

Reliance on honour system

The World Health Organization issued an advisory in mid-February calling on all countries to question all travellers about symptoms, and to implement "detection of ill travellers" at airports and border crossings to stem the COVID-19 outbreak.

Canada, facing criticism over a lack of screening both at international airports and upon arrival in Canada, imposed new orders to all airlines last Wednesday to prevent travellers with COVID-19 symptoms from boarding international flights to Canada.

But the "health check" imposed by Transport Canada — billed as "detection of ill travellers" — is a total honour system that simply requires airline staff to observe boarding passengers and ask them if they've felt ill or have had a fever.

Both Air Canada and WestJet said they have barred some passengers from boarding flights, but declined to say just how many.

CBC has spoken to many travellers who've recently returned to Canada who noticed the new questions posed when they boarded their flights home.

Eugene Haslam recently returned to Montreal from Paris. (Facebook/Eugene Haslam)

Eugene Haslam, who flew home to Montreal from Paris on Sunday on Air Transat, said the airline had signs, overhead announcements and staff asking questions before boarding. But he acknowledged this approach will only work if travellers are honest.

He said that he understands the need to "act accordingly" and not put "others at risk," but acknowledged that other travellers think differently.

"A lot of people will say, 'Screw it! I don't care!' And that's where the problem lies," Haslam said.

'We don't have superpowers'

The situation has air crews and their unions calling for more safeguards to prevent sick travellers from boarding aircraft.

"We're being told daily that there are people coming back ill. [There are] people coming back, you know, wearing masks, protecting themselves, but they're still ill passengers," said Wesley Lesosky, president of the Air Canada Component of the Canadian Union of Public Employees.

WATCH | Union president describes some of the anxiety airline workers feel

Sick travellers onboard pose threat to flight attendants says union 3:12

He said flight attendants are currently exempt from the 14-day self-isolation rules and that many are worried they are being unfairly exposed to the virus.

"We don't have superpowers. We need to realize that we're humans, too. And we can contract the same things that a passenger can on board," he said.

Canada has not yet adopted measures to test arriving passengers for the coronavirus, as is being done in at least a dozen countries around the world.

Commonly these are temperature checks or thermal screenings to detect passengers with a fever, and it's being done in countries like the United Arab Emirates, South Africa and Indonesia.

A health quarantine officer scans the temperature of students with a thermal scanner upon their arrival at Sultan Mahmud Badaruddin International Airport in Palembang, Indonesia. (REUTERS)

A number of Canadians flying home from Mexico this past week report that airport authorities in that country are screening all passengers for fevers using thermal-sensing cameras, noting Canada has no such technology in place.

'Dangerous' working conditions

Signs of stepped-up screening at the four Canadian airports that are still receiving international flights — in Vancouver, Calgary, Toronto and Montreal — include increased signage and additional Canada Border Services Agency officers asking passengers questions.

Flight attendants say it's simply not enough.

In recent days, they have been provided N-95 masks and gloves, but one flight attendant for Air Canada who works on transatlantic flights said she and her colleagues are being put at risk.

"Why aren't we forced to quarantine when we get back home?" she asked. (CBC is not naming her as she is not authorized to speak publicly.)

Flight attendants wear masks while travelling through the international departures area at Vancouver’s airport. (Ben Nelms/CBC)

"If I've caught something, I pass it on to many, many more!" she wrote in a text message. "We are just going to keep spreading it all over the world again."

"As much as I'm proud to repatriate all my fellow Canadians, I'm also getting scared to work in these dangerous conditions."

With files from Matthew Pierce