82 people in Atlantic Canada, N.W.T. have used COVID Alert app to enter positive results
Privacy features limit ability to gauge app's effectiveness in identifying cases early, says epidemiologist
Only 82 people in Atlantic Canada and the Northwest Territories have used the federal government's COVID Alert smartphone app to enter their positive COVID-19 test results, according to New Brunswick Public Health.
More than 1,240 people in the four Atlantic provinces and the territory have tested positive for COVID-19 since the app became active in each jurisdiction last fall.
People who test positive for the respiratory disease and have previously downloaded the app are given a "one-time key" to enter, which uses Bluetooth to identify and anonymously alert close contacts of the potential exposure so they can seek a test or self-isolate.
Public Health spokesperson Bruce Macfarlane declined to say how many of the 82 codes were issued in the province.
"Atlantic Canada [and the territories have] been grouped together due to privacy reasons given the low volume of reported cases," he said.
Although the app is available in Nunavut and Yukon, public health officials in those territories do not currently provide verification keys to people who test positive.
There's no way to determine how many New Brunswickers have been alerted by the Health Canada-run app that provincial officials have spent the past couple of weeks encouraging everyone to download, said Macfarlane.
That's "by design," he said in an emailed statement. "Otherwise there would be no privacy in the use of the app."
The phones of COVID Alert users exchange randomly generated codes with other nearby users every five minutes. Each day, the app scans the list of codes it has received from other users within the previous 14 days to check if any have reported positive test results, which is enabled by entering the one-time key codes.
The app does not collect any identifiable information or track a user's location.
It's hard to know exactly how well it's performing and that makes it harder to tailor it to work better.- Ashleigh Tuite, epidemiologist
The downside of that focus on preserving privacy is there's no way to gauge how effective the app is in identifying cases before they test positive and in thereby slowing the spread of the coronavirus, said Ashleigh Tuite, an epidemiologist at the University of Toronto's Dalla Lana School of Public Health.
It's impossible to know how many of the people who are notified choose to self-isolate or whether they subsequently test positive.
"It was a conscious decision that was made when the app was released because they really wanted to make people feel secure to download it and not worry that, you know, the government was collecting information on people," said Tuite.
"But the challenge is that it's hard to know exactly how well it's performing and that makes it harder to tailor it to work better."
Health Canada is seeking solutions, said spokesperson André Gagnon.
"We are currently exploring options for how we might gather more information on the app's effectiveness while still respecting privacy," he said.
New Brunswick reported 19 new cases of COVID-19 Wednesday, pushing the total number of active cases to 230 — the highest since the pandemic began in March — for a total of 836 confirmed cases to date.
A third resident of the Shannex Parkland Saint John Tucker Hall nursing home's memory care unit, Lily Court, has also died, Public Health confirmed. The death of the resident in their 70s puts the province's COVID-related death toll at 12. (The death of a 13th person who had COVID-19 was not related to the disease and is not included in the total.)
The surge of cases has prompted Chief Medical Officer of Health Dr. Jennifer Russell, Health Minister Dorothy Shephard and Education Minister Dominic Cardy to urge New Brunswickers during the last three COVID-19 news briefings to download the app.
The government has also been promoting the app through social media, despite glitches that prevented the app from functioning properly on some smartphones for much of November and part of December, leaving an unknown number of users without exposure notifications.
"It's critical that all New Brunswickers download the app," Russell said Monday.
"My understanding [is] it works exceptionally well," she told reporters during a COVID-19 briefing last week.
And if the highly-contagious U.K. variant of COVID-19 shows up in the province, the app will be "very, very, very crucial" in helping Public Health officials to contain it, she said.
Only 9% of New Brunswickers have downloaded it
None of the positive cases being investigated by Public Health officials as of last week involved individuals who had the app, Russell said.
Only about nine per cent of New Brunswickers have downloaded it so far, she said. That's roughly 70,200 people, according to Statistics Canada.
"But again, we really don't have a great breakdown of that just because [Apple and Google] release the information for the entire country," Russell told reporters. She did not say where she got nine per cent and as of Wednesday night, Macfarlane did not respond to a request for more information.
Experts have estimated an uptake of between 50 and 80 per cent is required for the app to be effective.
In urging people to download the app last Friday, Russell said, "I wish this would go viral. Somebody do a TikTok on this."
Downloading the app "would go a long way into helping the outbreaks currently and diminishing the risks in terms of future outbreaks by getting it contained earlier," she said.
More than six million people in nine provinces and territories have downloaded the app, as of Wednesday, according to the federal government's website — although this doesn't necessarily mean they have all installed it.
A total of 15,251 people across Canada have used their one-time keys.
2% of COVID-positive Canadians have used codes
While 82 key codes for Atlantic Canada and the Northwest Territories might seem like a small number, it's consistent with what's being seen across the country, Tuite suggested.
Only two per cent of people who have tested positive in Canada have activated the contact-tracing app, Health Canada figures show.
"I think it's important to remember that this is just one one piece of the puzzle," said Tuite, reiterating it's unclear how many people were notified by those users and subsequently identified as positive cases.
"Would we like it to be higher? Of course. But, you know, again, it's one tool that we can use to help find contacts."
Advantages of app
Tuite, who has downloaded the app on her own phone, thinks it's particularly useful during outbreaks, when Public Health officials might be overwhelmed by case counts.
Instead of having to wait for contact tracers to interview people who have tested positive and then track down all of their contacts, people can enter their one-time key as soon as they get their positive results and users they've come within two metres of for at least 15 minutes within the previous 14 days will be notified immediately, she said.
And the sooner people are notified, the sooner they can self-isolate and get tested, potentially reducing transmissions.
The app will also potentially find people who might otherwise not be found, said Tuite.
Contact tracers help people retrace their steps to remember who they've come into contact with, but the people they're most likely to remember are their highest-risk contacts, such as members of their household or social circle.
"If you were somewhere where there were lots of people around you, people that you wouldn't have another way to identify, you could still reach out to them via the app … and allow them to get tested or to speak to Public Health and figure out what steps they should take."
The app could become even more useful in the face of the U.K. variant, referred to by some experts as the B.1.1.7 lineage, said Tuite.
To date, most infections have occurred when people have been in relatively close contact for a relatively long period of time, she said. But the app is set to notify anyone within two metres for 15 minutes.
"If you have a more transmissible strain then those shorter, more superficial interactions may become more important."
WATCH | How the COVID Alert app works
Tuite thinks a recent update to the app might help with uptake. On Jan. 6, the Canadian Digital Service tweeted that people with iPhone 5s, 6 and 6 Plus can start using the app. It is now compatible with 97.5 per cent of all Canadian smartphones, including Android phones, it said.
Apple also created a fix for iOS 13.7 for the bug that in December had the director of Health Canada's COVID-19 task force urging people to open the app every couple of days to ensure it was working properly.
If the app wasn't opened regularly, it could lead some operating systems to treat it as a rarely used app, preventing it from running in the background, she said. This caused gaps in exposure checks for some users.
Now the app performs a background check at least once a day, the Canadian Digital Service tweeted. "This helps ensure there are no gaps in your exposure logs."
It's not a perfect piece of technology and it won't replace the role of traditional contact tracers, said Tuite.
"But I think, you know, as with many things during the pandemic, we sort of are doing the best that we can. And I think any little bit that helps is something that we should all be willing to, you know, try out."
The app was launched on July 31, when 116,000 cases had been reported in Canada. Nine provinces and territories are now handing out key codes. The others include Ontario, Quebec, Manitoba and Saskatchewan.