Correction: This article originally stated the researchers track mRNA in the cities’ wastewater. It has been updated to state researchers are tracking RNA.
The COVID-19 wastewater numbers for three major Saskatchewan cities spiked in the past 10 days, with an increase of nearly 900 per cent in Prince Albert. But a toxicologist said the figures are no cause for alarm.
That’s because that increase, and the accompanying jumps in Saskatoon and North Battleford of 614 per cent and 100 per cent, respectively, show a small increase over an even small number.
The numbers are not symptoms of a massive surge in the virus, John Giesy told Global News.
Giesy, a member of the University of Saskatchewan’s wastewater research team, said there’s been very, very little COVID-19 RNA in the three cities’ wastewater recently. That means increases of any kind will look relatively larger. The absolute numbers – the measure of the samples in the wastewater when not compared to previous weeks, are still very small.
“It might be one particle that’s there, and now we have six,” Giesy said.
“So it’s 600 per cent more, which is true, but it’s still a really small number.”
Wastewater samples have often foreshadowed new cases in the province – especially before vaccines were available – because infected people release the virus through their waste into the sewers before they start exhibiting symptoms.
Wastewater in Regina shows something similar. Tzu-Chiao Chao, a University of Regina molecular microbiologist and wastewater researcher, said recent numbers are also low.
“The trend seems to be moving up a little bit, but it’s only the first two data points, so it may very well reset itself,” he said.
The numbers from the UoR research team aren’t as recent as those from the USask group and are measured relative to a prior date with lots of COVID-19 in the city, but still show only a small increase.
The UoR team determined there is 22 per cent as much COVID-19 in the water as there was on April 18, as of Nov.21. Data from one week and two weeks prior aren’t finalized yet but show a slight decrease and then increase, Chao said.
“The slight uptick is not enough for us to… give any kind of certainty towards the overall trend,” he explained.
Both Giesy and Chao said they are testing for the Omicron variant and haven’t detected it yet.
Both also said they expect numbers to increase after the holidays.
“The only thing we are bit nervous about is really the time after the festivities,” Chai said.
“We’ve still got more than a week to go on Christmas, so we can just hope that its stays that way.”
And they both say a sustained increase will be cause for concern and not just a statistical oddity.
Data collected in upcoming weeks will reveal whether the numbers continue to rise.
To that end, they agree on another point – that people should be cautious.
“As long as the large proportion of the world is unvaccinated, (the virus) is going to keep changing. And that’s a worry,” Giesy said.
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