Wastewater samples in Saskatoon show massive increase in the Omicron variant

Wastewater samples in Saskatoon are seeinga majorincrease in the Omicron variant since it wasdetected for the first time in the city last Tuesday.

The latest samples tested by the Global Institute for Water Security (GIWS) at the University of Saskatchewan show Omicron constitutes 64.1 per cent the overall COVID-19viral load in the Saskatoon sample.

It is an increase of 808.2 per cent since the variant was first detected in Saskatoon wastewateron Dec. 21.The viralload in Saskatoon's wastewater has increased by 87.7 per cent since then.

"The Delta variant took about a monthto become the dominant strain. For Omicron, over Canada and around the world,it's only taken about two weeks. It was expected Omicronwould peak pretty quickly,"said Kerry McPhedran, an associate professor of environmental engineering with the institute.

He said it is because the strain ismore easily transmissible than Delta and can affect vaccinated people.

"Relatively speaking, compared to previously there'sless virus load in the wastewater, butwe will expect probably the peak to go up again next week,"McPhedran said. "We mightget another200 or 300 per centkind of increase at the next reading."

When higher levels of virus are found in wastewater, it tends to suggestanincrease in infections in the coming weeks. However,the Uof Sresearchers saida spike in new cases isnot guaranteed, due to the fact that much of the population is vaccinated.

"It becomes a bit more difficult to to track the cases versus the wastewater, especially when you have certain higher vaccination rates," he said.

Future trends

McPhedran said he is hoping the numbers do not go up again, but it might take another two weeks to understand the future trends and "to predict whether it's going to be a huge peak or not."

"If we see the percentage increase go down next week, then that might indicate that we actually have reached a peak already," he said, noting that would be good.

Factors such as the increasing number of people who have received booster jabs and the amount of in-person socializing over the holiday period will likely have an impact on the case count,McPhedran said.

Meanwhile, two of the three cities being monitored by researchers at the U of Shave shown a drop in the amount of the virus that causes COVID-19 in sewage samples taken during the latest testing period.

These include Prince Albert and North Battleford. Bothsaw a decrease in the viralload in their wastewater.

Viralload in Prince Albert's wastewater has decreased by 86.6 per cent in the latest reporting period.

In North Battleford, the wastewater has seen a decrease of 85.7 per cent in its viralload.

"We mighthavepretty similarpeaks [like Ontario and Quebec], although since we are a bit more isolated inSaskatchewan each area has differentpeaksas the wastewater shows now," McPhedransaid.

While none of the samples analyzed in North Battleford so far have tested positive for the omicron variant, samples collected on Dec. 15 and 17 in Prince Albert have tested positive for the variant of concern.

However, since the readingswere just slightly above the limit of detection, their interpretation should be exercised with caution, the U of S report says.