05/07/2020 17:21 EDT

How Do Coronavirus Contact Tracing Apps Work?

Alberta’s government launched ABTraceTogether last week, to mixed results.

Since the COVID-19 pandemic hit Canada, thousands of volunteers and public health workers have practised  contact tracing — the painstaking process of identifying anyone who’s come into contact with someone diagnosed with the disease and telling those people they need to self-isolate.

It’s intensive work. But is there a way to do that work digitally? 

Some developers and governments are trying to find out. B.C. chief medical officer of health Dr. Bonnie Henry summed it up during a news conference Tuesday. 

“Everybody and their dog has an app out right now,” Henry said with a laugh. 

And she’s not wrong. Jurisdictions around the world are researching and developing ways to digitally trace people’s contacts in order to contain the spread of COVID-19. Both government and privately developed apps have been downloaded millions of times as countries  try to find the best way to keep COVID-19 infection rates low. 

Everybody and their dog has an app out right now.B.C. chief medical officer Dr. Bonnie Henry

But how does digital contact tracing work? How legitimate are these apps? And how do they interact with Canada’s privacy laws?

What is contact tracing? 

Contact tracing is a process that is used to identify and find people who were in close contact with someone infected with a virus, the coronavirus in this case. The idea is that these people are at a higher risk of becoming infected themselves and spreading it, so if they’re identified early, public health agencies can test and monitor them and  hopefully to prevent unknown spread. 

So far, contact tracing in Canada has largely been done by real human beings. Trained volunteers and staff members across the country have been deployed to get in touch with anyone who’s been in contact with someone confirmed to have COVID-19. 

WATCH: What is contact tracing and how does it work? Story continues below. 


But technology, like phone apps and artificial intelligence, can speed up that process and make it a lot more accurate.

What’s happening in other countries?

Countries further along the COVID-19 curve, like Singapore and South Korea, have utilized robust contract tracing in an attempt to keep COVID-19 case numbers down. 

Singapore launched a contact-tracing app in mid-March, while Australia has also developed an app that its prime minister considered making mandatory — he later walked that back. 

In South Korea, government-developed technologies have also been supplemented by privately developed apps to fill in perceived gaps. 

Apps like Corona 100m and Corona Map plot the location of COVID-19 patients and communicate that to users who want to avoid contact with them. Corona 100m will send a push notification to users if they get within 100 m of someone confirmed to have the virus, and provide information like age, gender and nationality to them. Both apps skyrocketed up the download charts, with millions of downloads.

Hong Kong took it a step further, using tech  not only to contact trace, but enforce mandatory 14-day self-isolation for new arrivals to the territory. The Hong Kong government required each new arrival to download the StayHomeSafe app, gave them a paired wristband and then used location tracking technology to catch people violating self-isolation orders. 

What’s the deal with Alberta’s new app?

Last week, Alberta launched ABTraceTogether, the first provincial public health authority contact tracing app. It’s a modified version of Singapore’s app, which uses “digital handshakes” to track contacts. 

The app works by using Bluetooth to keep an anonymous log of other app users you’ve been in contact with. If someone with the app tests positive for COVID-19, they’ll be asked to volunteer to give the information from their app, then Alberta Health Services uses the  information to contact everyone who’s been in contact with that person. 

Alberta chief medical officer of health Dr. Deena Hinshaw updates media on the COVID-19 situation in Edmonton on March 20, 2020.

It’s the sort of thing that works better the more people who sign up, since you have to have the app to have your contacts tracked. And it’s already run into a few roadblocks.

Namely, it only works if your phone is turned on and the app is running in the foreground. So not only must you have the app, but it has to be open and with your phone unlocked for it to trace anything. 

Over 100,000 people downloaded the app in its first weekend, according to chief medical officer Dr. Deena Hinshaw. That’s about two per cent of Alberta’s population, while other countries like Australia have suggested an uptake of around 40 per cent of the population is needed for apps like these to be of use.

“I hope more Albertans will choose to download the app to increase our contact tracing ability,” Hinshaw said Monday. “We need to gather as much accurate information about how the virus is spreading as we can.”

What about the other provinces?

In B.C., Henry said they’ve been exploring and researching possible contact tracing apps, but  none have been deemed satisfactory.

“We’re not clear that there’s any evidence, at least in our context, that having something on everybody’s phone giving them generic messages about where they’ve been or who they’ve been in contact with is what we need right now,” Henry said. 

Provincial health officer Dr. Bonnie Henry responds to questions while B.C. Premier John Horgan and Health Minister Adrian Dix listen behind during a news conference in Vancouver on March 6, 2020.

She said the province is particularly looking at ways to augment existing IT infrastructure to assist with contact tracing, rather than developing a brand new app. 

In Ontario, Premier Doug Ford has called on the federal government to investigate digital contact tracing on a national level. 

“We need a national plan for contact tracing. Right now each individual province is doing it, but we need a national plan, to work with the federal government and all the provinces, the 10 provinces and the three territories,” said Ford. “It’s absolutely critical moving forward for many reasons.”

Are there concerns about privacy?

Apps like Corona Map and Corona 100m can function as they do in South Korea because of vastly different privacy laws than in Canada. Providing personal information about strangers and push alerts about their location simply isn’t possible under Canadian privacy laws. 

In a statement Thursday, Canada’s privacy commissioner Daniel Therrien said technology can be part of the solution to address the COVID-19 pandemic, and can fit into our privacy laws. 

We need a national plan for contact tracing. Right now each individual province is doing it, but we need a national plan.Ontario Premier Doug Ford

“If done properly, tracing applications can achieve both privacy and public health goals at the same time. Everything hinges on design, and appropriate design depends on respect for certain key privacy principles, “ Therrien said.

There are concerns that an app could be used for other purposes that could violate peoples’ privacy, such as law enforcement. Officials have said any app would have to be for the sole purpose of tracking the virus, and could not be used for anything else. 

The Office of the Privacy Commissioner of Canada recently put out an assessment framework to evaluate privacy issues when it comes to COVID-19 responses.

The framework encourages anyone developing tech to consider areas such as legal liability,  de-identification, time limitations and the unique impact on vulnerable populations, among other factors.

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