Sask. wastewater data shows BA.5 variant growing strain, except in Prince Albert

The viral load of COVID-19 in some Saskatchewan cities' wastewater remains below 2022 average despite a spike in North Battleford since the previous report.

3 cities measured for COVID-19 in waste show less than average viral load

CBC News Posted: Aug 01, 2022 1:45 PM EDT | Last Updated: August 1, 2022

A look at the UV filtering system used at the City of Saskatoon's wastewater treatment plant. The data from the research into COVID-19 in wastewater shows that while there have been increases from previous weeks, the overall viral load remains low. (Submitted by the City of Saskatoon)

University of Saskatchewan researchers using wastewater to determine the breadth of COVID-19 in the community have found the Omicron subvariant BA.5 is becoming more prominent but isn't quitethe dominating strain of the virus in the province.

The latest report released from the research team Sunday said the total viral load remains "relatively low, which indicates a fairly constant level of infections in all three cities," meaning includes Saskatoon, North Battleford and Prince Albert.

A graph representing the absolute viral load of COVID-19 found in wastewater up to the end of the reporting period on July 27, 2022. (John Giesy)

John Giesy, a lead researcher on the project, says the take-home message is everything is low. He also saidthat Delta is no longer being found in wastewater and has been replaced by Omicron.

Of the three cities, Prince Albert is the only city where the BA.5 subvariant is not becoming more pronounced in the COVID-19 landscape.

This most recent report found the subvariantcomprised 45.9 per cent of known infections in Saskatoon and 48.1 per cent in North Battleford.

Lead researcher at U of S COVID-19 wastewater research team says future of study uncertain

COVID-19 viral loads up in 3 Sask. cities, showing signs of 7th wave

In Prince Albert, this most recent study did not find any any viral load with the BA.5 subvariant, compared to the prior report which found it composed about one-fifth (19.4 per cent) of infections.

Giesy said he "has no idea" why there's a notable absence of the strain but said the virus tends to have a delayed effect on the city, following a couple weeks later than Saskatoon.

That doesn't mean there isn't BA.5 in Prince Albert, but that there areso few cases that it's not being picked up in their research, Giesy said.

Instead, BA.2 andits subvariantswithBA.2.12.1 being most prominenthave a strong foothold when it comes to COVID-19 infection in the city.

The most recent data from Prince Albert found that BA.2 and its subvariants compose all of the viral load found in wastewater, despite BA.5 increasing in other cities where the wastewater is tested. (John Giesy)

COVID-19 viral load below average

Despite a spike in viral load in North Battleford, an increase of 214.7 per cent from last week, and a slight increase in Saskatoon, the researchers sayall three cities remain below the average load measured since January 2022.

"The main thing is they're all pretty low," Giesy said.

"When we're near our detection limit and there are not that many infected individuals, things bounce around a little bit."

The University of Regina, which records the wastewater data for Regina, said in a note posted to social media that its results would be shared on Tuesday.

CBC's Journalistic Standards and Practices|About CBC News

Corrections and clarifications|Submit a news tip|