What is coronavirus contact tracing and how important is it as Canada reopens?

Click to play video: 'Coronavirus outbreak: Trudeau says Ottawa will help fund contact tracing across Canada'
Coronavirus outbreak: Trudeau says Ottawa will help fund contact tracing across Canada
WATCH: Coronavirus outbreak: Trudeau says Ottawa will help fund contact tracing across Canada – May 22, 2020

Contact tracing is one of the key tools necessary to quell COVID-19, the disease caused by the novel coronavirus, according to experts.

As provinces and territories reopen slowly and by varying degrees, contact tracing will become even more important — a way to track down people who might be infectious and keep them away from other people, which can help prevent a positive case from growing into an outbreak of several cases.

“Contact tracing is one of several important components to managing this epidemic and actually managing any epidemic,” said Dr. Isaac Bogoch, an infectious disease specialist based out of Toronto General Hospital.

READ MORE: How does COVID-19 contact tracing work? Alberta doctor explains

Experts agree extensive contact tracing is necessary to reduce the spread of the virus as the country cautiously reopens bit by bit.

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We really need to up our contact tracing so that we can figure out where things are coming from,” said Dr. Samantha Hill from the Ontario Medical Association in an interview with Global News Radio.

“That’s how you shut down an epidemic, you shut down transmission from one person to the next.”

How does it work?

Contact tracing works in tandem with COVID-19 testing in order to limit the spread of the virus. As people test positive, trained tracers figure out who their close contacts were over the prior two weeks.

Click to play video: 'Alberta’s contact tracing app to get software update, but problems continue'
Alberta’s contact tracing app to get software update, but problems continue

Contact tracers are trained to essentially call up people who have tested positive for COVID-19 and gather information on where they have been and who they might have been in touch with over the past 14 days, according to Bogoch.

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Then they get in touch with as many people as possible who might have had close contact with the positive individual, but without revealing identities.

They walk them through what they need to look out for in terms of signs and symptoms of infection; what they might need for a 14-day isolation at home; and who to contact if something develops.

READ MORE: Coronavirus: More than 27,000 Canadians register as volunteers to help provinces

The whole process is “labour intensive,” Bogoch said.

“It might take a little bit of time to do it, but it’s not hard to train people how to do it,” he said. “And it’s extremely important work to be done.”

What is Canada doing?

The federal government is mulling over several smartphone apps to help contact tracing efforts. Technology has been used in other countries — at times extensively — to conduct mass contact tracing.

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For example, South Korea is using a new data-sharing system introduced in March that patches together cellphone location data and credit card records.

This system allowed South Korean authorities to trace the movements of the first person detected positive in Seoul’s latest outbreak, which has been linked to a nightclub. So far the country has seen 11,142 cases and 264 deaths.

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READ MORE: Trudeau says Ottawa will help fund coronavirus contact tracing across Canada

In Canada, an app could help track anyone the user has been in close contact with, and alert them if they have been near someone with a confirmed or presumed case of COVID-19.

A number of provinces have looked at developing their own contact tracing apps. Alberta is already using one. Ontario Premier Doug Ford has said he supports a national, co-ordinated approach.

Federal contact tracers are already helping public health authorities in Ontario — more than 200 of them are helping trace contacts of positive cases.

Click to play video: 'Doug Ford encourages anyone who needs coronavirus test to get tested'
Doug Ford encourages anyone who needs coronavirus test to get tested

Prime Minister Justin Trudeau has said they’re ready to make thousands more calls a day when any province asks. Statistics Canada has also provided 1,700 interviewers who can make 20,000 calls per day to help with contact tracing efforts, he added.

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“We need to get in touch with everyone who may have been exposed to the virus to make sure they quarantine and monitor themselves for symptoms or get tested,” Trudeau said on Friday.

For Bogoch, it’s a little difficult to assess how Canada is doing so far in terms of contact tracing. Public health regions are “performing differently,” he said.

READ MORE: As Canada reopens, are we ready for a ‘second wave’ of coronavirus infection?

Strictly anecdotally, Bogoch said he has, in general, heard of contact tracing done “efficiently” in some settings and “very slowly” in others.

“And a lot of it comes down to resources,” he said.

If enough people buy in to the idea of an app, then it can help complement existing contact tracing efforts. But an app is not a blanket solution, he added.

Click to play video: 'Coronavirus outbreak: Dr. Njoo says federal government ready to support provinces on contact tracing'
Coronavirus outbreak: Dr. Njoo says federal government ready to support provinces on contact tracing

He’s not the person to warn against putting too much faith in digital technology. Canada’s deputy chief public health officer Dr. Howard Njoo also warned Friday that apps are not a silver bullet.

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Benoit Barbeau, a professor in the biological science department at the Université du Québec à Montréal, said it appears Canada is just starting to ramp up its contact tracing. The country has “not necessarily been proactive” in increasing testing or tracing.

Transmission by asymptomatic or presymptomatic but contagious people, for instance, has been “a real important problem.”

READ MORE: Inside officials’ struggle to trace the contacts, movements of COVID-19 patients

“Contact tracing will at least make these people aware that they might be carriers even though they are not showing any symptoms or have not yet developed any symptoms,” Barbeau said.

Second wave

A second wave is not a matter of if, it’s a matter of when.

As Canadian Medical Association president Dr. Sandy Buchman said Friday, a second wave of COVID-19 is “inevitable.”

“There’s never been a pandemic in recorded history that didn’t have a second wave, and often that second wave is even worse than the first,” he told Global News Radio. 

Reopening in a way that minimizes deaths and cases can be done with “good data.” And that good data comes from testing extensively, to find out where exactly new cases are coming from.

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Only then can you trace.

READ MORE: COVID cases in Canada tracker: How many new cases of COVID-19 today?

We have to be able to identify hot spots, because then you can trace,” Buchman said.

Tracing means some people would stay home, under quarantine, while others could then go back to work or go back to school.

If we identify more hot spots or people getting sick, we can slow down a little bit,” he said.

“If we find that we’re not seeing the disease out there, we can open up more. So it’s kind of a win-win both ways. That’s really what we’re calling for.”


In Canada, the COVID-19 epidemic is at a different stage across the country — some urban areas have high figures, while other provinces (such as New Brunswick) have reached a point where they’re going days or weeks without a new case.

That is why, for many parts of the country, it’s “completely reasonable” to lift some of the restrictions from the lockdown.

Mainly, you know, the the eastern provinces, the prairies, Alberta, British Columbia, these are places that by and large have this epidemic under much better control,” Bogoch said.

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Click to play video: 'Saskatchewan restaurant owners eyeing reopening day with caution'
Saskatchewan restaurant owners eyeing reopening day with caution

But there’s still a concern about testing levels in provinces like Ontario and Quebec, which collectively report the overwhelming majority of new daily cases in Canada in recent weeks.

“There’s obviously the concern that if we don’t have the diagnostic testing capacity — or maybe we have the capacity, we’re just not using it — and if we don’t have the appropriate level of contact tracing in place now, we can certainly contribute to greater community transmission,” Bogoch said.

— With files by The Canadian Press, Reuters

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