Mobile contact-tracing app can help Alberta slow spread of COVID-19, top doctor says

A new mobile contact-tracing app unveiled Friday by Alberta Health Services, combined with aggressive testing for COVID-19, can help public health officials slow transmission and reduce the spread of coronavirus, says Dr. Deena Hinshaw.

Alberta's Chief Medical Officer of Health announced the launch of ABTraceTogether, a mobile app that uses Bluetooth technology to identify other nearby cellphones that also have the app installed.

People with the app on their cellphones who later test positive for coronavirus will be asked to voluntarily upload encrypted data to Alberta Health Services contact tracers. Those tracers would then be able to use that information to track down people who had close contact with the infected person.

"The faster Alberta Health Services contact tracers can inform exposed people, or close contacts, the quicker we will be able to prevent potential outbreaks and identify when Albertans must self-isolate," Hinshaw said at a news conference on Friday.

"I have already downloaded the app myself, and I encourage you to do so, too. You can aid in our work to keep Albertans healthy, and provide crucial information about the spread of this dangerous illness."

From the beginning of the pandemic, public health officials in Canada and around the world have repeatedly stressed the vital role that testing and contact tracing will play in efforts to slow the spread of coronavirus.

Hinshaw said under the current manual process, public health workers interview people infected with COVID-19 and ask them questions that rely on their ability to remember where they have been in the past several days and who they were near.

'Encrypted digital handshake'

"These people, their contacts, are then called to find out if they are sick and to make sure that they stay home for 14 days from their last exposure, even if they are feeling well.

"This is a vital step in preventing further spread of the virus. It is also time-consuming and resource-intensive, relying on each individual's ability to recollect who they may have come in contact with, and then follow up with each of those individuals, in order to be successful."

ABTraceTogether relies on wireless Bluetooth technology to log interactions as what Hinshaw called "an encrypted digital handshake."

That happens, she said, when two phones that each have the app get within two metres of one another for a total of 15 minutes within a 24-hour period of time.

"In the event someone with the app tests positive for COVID-19, they will be asked to allow contact tracers at Alberta Health Services to use this information to further enhance manual contact tracing, and allow other app users to be contacted so they can be informed if they have been potentially exposed."

User identities will not be shared, she said. Users will be informed that they have come into close contact with someone who has tested positive for COVID-19.

Downloading app is voluntary

In the past, Hinshaw said, public health officials would have no way to know about encounters a COVID-positive patient can't recall or about strangers they were in contact with. With the app, that will be possible, she said, and AHS can contact people and let them know they may have been exposed to COVID-19.

"The use of technology for this purpose may seem intrusive," Hinshaw said. "But downloading the app is completely voluntary and data will not be accessed unless a user provides consent to share their data with AHS."

The app does not use a phone's GPS or track location or contacts.

"Data is stored on your phone in an encrypted form for 21 days," she said. "After 21 days each day's worth of data is deleted, one day at a time."

Singapore, South Korea and Australia have similar apps, but the Alberta version does not collect as much information, and asks users only for their phone numbers not for names, ages and postal codes.

AB TraceTogether is based on Singapore's TraceTogether application. Singapore offered the source code for its application free to other countries, and Alberta spent about $625,000 to develop the app for use here.

Privacy chief to monitor app

Information and Privacy Commissioner Jill Clayton issued a statement on Friday saying her office received a privacy impact assessment on the app earlier this week.

An initial review was undertaken and questions were sent to Alberta Health to clarify certain aspects of the PIA, the statement said.

"For example, I am seeking confirmation that the data collected through this app is to be used for contact tracing, and not for any other purpose," Clayton said in her statement. "My office will monitor the implementation of this app.

"Any individual concerned about how their personal or health information is collected, used or disclosed may submit a complaint to my office."

3 more deaths

Alberta reported three more deaths, all of whom were residents of continuing care homes, from COVID-19 on Friday and 218 news cases.

That brings the total number of deaths to 92, and the total number of cases to 5,573.

The number of people who have recovered is 2,359.

The regional breakdown of the cases as of Friday was:

• Calgary zone: 3,708

• South zone: 1,033

• Edmonton zone: 498

• North zone: 215

• Central zone: 87

• Unknown: 32

Alberta has conducted 153,766 tests for COVID-19 since the first case was detected in the province eight weeks ago.

Much has been learned

Hinshaw said much has been learned about the virus since the first case was discovered in Alberta in March.

While older people are at the highest risk of severe symptoms, the average age of cases in Alberta to date is 41.5 years, she said.

The most common symptoms associated with COVID-19 are:

• Cough (reported by 62 per cent of all cases)

• Sore throat (33 per cent)

• Fever (28 per cent)

Hinshaw said 7.5 per cent of all cases showed no symptoms when they were tested.

She said investigations have also uncovered the conditions that tend to be present in cases of severe disease.

"We looked at whether cases had been previously diagnosed with one of nine conditions, including cancer, diabetes, high blood pressure, respiratory disease and immune deficiency. As well, we also see if a case had been reported to have obesity or a history of smoking.

"From the data so far, we've found that people between the ages of 30 and 64 are more likely to have a severe outcome — needing hospital or ICU treatment, or in the worst outcome, leading to death — if they had at least one of these health conditions."

In the age group, Hinshaw said, two-thirds of hospitalized cases, and almost three-quarters of those who died, had at least one of those conditions.

"We found the three most common factors in cases of severe outcomes, such as ICU and death, are older age, obesity and immunodeficiency."