Alberta's contact tracing raises red flags as 43% of new cases have no known source

COVID-19 cases are rising in Alberta, and there are concerns that difficultiesinvolved in contact tracing both manual and digital could hamper the province's ability to slow the spread.

Of the 1,812 new cases reported in Alberta last week, 772 (43 per cent) have an unknown source. There are currently 2,836 active cases in the province, 1,054 (37 per cent) froman unknown source.

Dr. Lynora Saxinger, an infectious disease specialist at the University of Alberta in Edmonton, said she doesn't like the look of those numbers.

"This is actually one of the cornerstonesof reducing spread. If we can't, basically, kind of find the ring of exposed people and prevent them from spreading it outwards, we're going to be looking at really, really bad numbers. So it's a big deal," she said.

Contact tracing isthe process of identifying, notifying and tracking the spread of the virus from individual to individual.

Alberta's team of contact tracersspeak to people who have tested positive in order to identify who they have been in close contact with during the previous 14 days. Those close contacts can thenbe instructed to self-isolate and get tested.

Lori Henneigh, acting manager with an Alberta Health ServicesCOVID-19 outbreak team in Red Deer, Alta., told CBC News last month that people often have difficulty remembering what they did 14 days ago.

"If you think about it yourself, if you try to think about what you did in the last 14 days, you'll realize that it's not easy to recollect what you did two weeks prior," she said. "We certainly can ask them to look at statements bills, receipts and things they have at home to help them remember their activities in the last 14 days."

Tom McMillan, a spokesperson for Alberta Health, said the province has been working to bolster its contact-tracing capacity, including through an agreement with the federal government to loanemployees to support its 1,000-person team. As of September, 15 Statistics Canadaemployees had been assigned to support Alberta's contact tracers.

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Contact tracing can be a slow process, with one tracer saying theaverage investigator completes just one to twocasesper day, and it depends on how candid each COVID-19 case is with their interviewer.

Dr. Deena Hinshaw, Alberta's chief medical officer of health,said earlier this week that more Albertans are showing reluctanceto share key information with contact tracers including where they've been while infectious.

"It is understandable that people are tired of COVIDand angry at theways that their lives have been disrupted. Unfortunately, choosing not to work with contact tracers does not make that better. It makes it worse," Hinshaw said.

"If you are diagnosed with COVID, please don't turn any understandable anger against the contact tracers, who are doing their job as part of a collective effort to maintain manageable levels of transmission."

Saxingersaid that's a problem.

"I would consider that a big red flag for problems ahead, honestly," she said.

Still no timeline on Alberta's switch to national app

Those difficulties are why many experts have touted mobile contact-tracing apps as an important tool for the pandemic response, but Alberta is also having problems on that front.

The government announced in August that it would move from its provincialCOVID-19 tracing appto the national app, buttwo months later, it remains unclear which details still need to be worked outtosee that transition take place.

Prime Minister Justin Trudeau said on Friday that Ottawa continues to work with Alberta to get the province on board.

Alberta's app hashad technical difficulties, like the fact that until late September, it didn't function on anyiPhones unless the app was open and the phoneunlocked, instead of being able to run in the background.

The federal appuses Bluetooth technology.If two people are within two metres of each other for more than 15 minutes, the app records a potential exposure. If someone with the app is diagnosed with COVID-19, they can choose to record that in the app. The app would then notify people that person came into contact with without telling the users who the person was who tested positive.

McMillanof Alberta Health said the province remains in discussions with Ottawa.

"We are working with the federal government on how to transition the hundreds of thousands of users of Alberta's tracer app over to the federal program," he said.

Alberta's ABTraceTogether app has nearly 247,000 users, or nearly six per cent of the province's population.The federal COVID Alert app has nearly4.5 million users,or about 12 per cent of the country's population,in Ontario, Quebec, Manitoba, Saskatchewan, Nova Scotia, New Brunswick, P.E.I. and Newfoundland and Labrador.

The federal privacy commissioner has toldCanadians that the federal app is safe, saying he will download it himself.

• Toronto Public Health halts contact tracing outside of COVID-19 outbreaks in facilities

Toronto could perhaps stand as a cautionary tale of how contact tracing can collapse once cases surge.

Earlier this month, the city became unable to cope with the number of new cases and halted contact tracing outside of outbreaks leaving each infected person to call their close contacts themselves.