COVID-19 viral loads in major Sask. cities' wastewater at highest levels in months

The COVID-19 viral loads in some of Saskatchewan's major cities are the highest they've been in months, according to the latest weekly report from University of Saskatchewan researchers.

Researchers with the university's Global Water Futures program have been analyzing wastewater samples from Saskatoon, North Battleford and Prince Albert for COVID-19 since summer 2020.

The study's results can help predict a rise or fall of COVID-19 diagnoses about a week in advance.

In an email on Sunday, the team's lead researcher John Giesy said the viral load has "increased significantly" in all three cities, continuing a 10-week trend of upticks.

"Not only are the viral loads increasing, but the rate of increase is accelerating," he said in an email.

"The observed loads are approaching 50 per cent of the maximum values observed during the sixth wave."

In Saskatoon, the viral load increased by 77.6 per cent compared to last week's results and was above the 10-week average.

In Prince Albert, the viral load increased by 101 per cent to its seventh highest value since the beginning of 2022 and the highest in the past 18 weeks.

Giesy said North Battleford hasn't increased as quickly as the two other cities involved in the project, but still had its highest value in the past 13 weeks, with a 47.6 per cent increase from last week's report.

Giesy said the researchers have a four-level index ranging from green to red to classify severity. The most recent numbers for all three cities are in the red zone and are considered a very high or critical risk.

Omicron composes all of the COVID-19 found in all three cities. The BA.5 Omicron subvariant accounts for about 50 per cent of the COVID-19 particles found in Saskatoon and North Battleford wastewater and nearly 30 per cent in Prince Albert.

Regina viral load remains high

The University of Regina has been scanning that city's wastewater for COVID-19 since August 2020. 

Before the Omicron waves, some of the highest recorded values in Regina came in April 2021. In the U of R's most recent report, released Monday, the levels of viral load were more than one-and-a-half times higher than that period. 

The university said the viral levels have increased slightly since its last report and remain high.

Small communities to do own sampling

Giesy said the program has also received six Cepheid GeneXpert systems — which will allow people in other communities to take and test samples with minimum training — and will be providing them to those who need them in two small cities and five First Nation communities.

He noted some of these communities already have the necessary systems and just require training.

Giesy said it's more difficult to gather and test wastewater from smaller communities.

He said the best way to help them is to "empower them to do their own monitoring and teach them what they need to know so that they can do it and use the data immediately themselves for whatever purposes they deem."

"We will be training local citizens in each community to use the systems so that they can conduct community-based monitoring."

While Giesy's researchers provide an in-depth look at wastewater tests, he said the units provided to communities will provide semi-quantitative information, something like a "low, medium and high kind of a thing."

Right now, the team is working to calibrate the units with their own findings, attempting to make them as accurate as possible.

Giesy chose not to share the names of the First Nation communities, saying he would allow them to decide whether they will share their inclusion in the project.

Those units, which cost about $65,000 each, can be tailored to track other viral and bacterial diseases like influenza, polio and the common cold, Giesy said.