Alberta COVID-19 wastewater readings increase as subvariant now dominant strain

Wastewater readings in Alberta are trending up, indicating new COVID-19 infections are rising amid the Omicron subvariant BA.2 becoming the dominant strain of the disease in the province.

Top doc says BA.2 more transmissible but doesn't appear to cause more severe disease

Tracking COVID-19 by wastewater can help forecast test positivity, hospitalizations and deaths, and is being used across the country as testing has been scaled back. (Submitted by Riley Brandt, University of Calgary)

Wastewater readings in Alberta are trending up, indicating new COVID-19 infections are rising amid the Omicron subvariant BA.2 becoming the dominant strain of the disease in the province.

Those higher readings mirror trends across Canada and a recent rise in global COVID-19 cases. 

Alberta data from a dashboard created by the University of Calgary Centre for Health Informatics shows the average amount of COVID-19 detected in wastewater.

Kevin Frankowski, the executive director of Advancing Canadian Wastewater Assets (ACWA) at the University of Calgary, said the amount of virus circulating in the community is staying relatively high.

"Based upon the wastewater numbers, it's clear that COVID isn't over yet. We're not out of the woods yet," he said. "It's important to remain vigilant."

Data from a dashboard created by the University of Calgary Centre for Health Informatics shows the average amount of virus in wastewater in Calgary and the surrounding area. (University of Calgary Centre for Health Informatics)

Numbers during the Omicron wave were much higher than they are currently, but the dashboard's last three data points have tracked an increase in levels after staying relatively stable for some time.

Despite that, Frankowski said, hospitalization numbers keep coming down. The number of people in hospital was down 10 from Friday, for a total of 945. The number of Albertans in the ICU also went down, from 62 to 56.

"So that means whatever virus, whatever variant of the virus is circulating now, BA.2, causes less severe health outcomes," he said. "But it's still very prevalent."

Frankowski said Edmonton looks similar to Calgary in recent days, though numbers have bounced around more and have not shown the same consistent increase seen in Calgary.

More transmissible variant

Wastewater testing, along with hospitalizations, are among the best tools available to illustrate how much virus is circulating around the country amid the collapse of COVID-19 testing.

COVID-19 public health restrictions have been loosening across Canada in recent weeks, with Alberta lifting nearly all of its restrictions three weeks ago.

The province has also reduced reporting on COVID-19 numbers to once a week, instead of every weekday.

Speaking at Wednesday's update, Dr. Deena Hinshaw, the province's chief medical officer of health, said that though BA.2 is more transmissible than BA.1, so far there is no evidence of it causing more severe disease.

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However, Hinshaw added that more transmissible variants can still have a large impact on populations.

"Those at risk of severe outcomes should revisit their precautionary measures," she said.

Twenty-one more deaths were reported on Wednesday since the previous update on Friday, bringing the total number of Albertans who have died from COVID-19 to 4,044. That number is current up to end of day Monday.

Lynora Saxinger, an infectious disease specialist at the University of Alberta, said the rise in wastewater numbers is not unexpected but is a bit of a caution flag.

"The trend is something that's concerning, and it's kind of unpredictable as well. And, again, then the number of infections in the community are going up based on that," she said.

Frankowski said it will be important to monitor the data and continue to take personal responsibility for one's health.

"This virus isn't going away, right? We're not going to get back to pre-COVID times," he said. "But maybe it gets to the point where it's more manageable."


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