As Sask. reports record high test positivity, expert says we may no longer understand COVID spread
Since testing has been cut back, numbers are skewed
As nearly every health zone in Saskatchewan reports a record high test positivity rate, one expert said the province no longer truly understands how far COVID-19 is spreading.
Nazeem Muhajarine, a professor of epidemiology at the University of Saskatchewan, said the number of cases the province is reporting is no longer accurate.
"I think it has really got away from us," he said, adding that the situation is telling, two years into the pandemic.
One of the other metrics scientists look at to track the spread of COVID-19 is the test positivity rate, which is the percentage of the total COVID-19 tests performed that produced a positive result.
It is a good way to understand the level of community transmission.
A high test positivity rate — even when the overall number of tests done is low — shows there's a lot of transmission.
But during the past few weeks, even that has come with a caveat.
In an attempt to preserve testing capacity in the province, Saskatchewan has moved to only recommending those with "serious symptoms" get a PCR test.
Everyone else is supposed to use rapid tests to diagnose themselves as having COVID-19 or not.
Even though the test positivity rate is only showing the most serious cases of the virus right now, that rate is sky high across the province.
Test positivity skyrocketing
As the Omicron variant has become the dominant strain in Saskatchewan, nearly every health region in the province has reported record-breaking test positivity.
Some of the highest are in the major urban centres of Saskatchewan.
As of Wednesday, the seven-day rolling average test positivity rate reported by Saskatoon was 41 per cent and for Regina it was 42 per cent.
A seven-day rolling average is used in order to eliminate daily fluctuations in testing.
Even during the depths of the fourth wave — the deadliest period in the pandemic for Saskatchewan — the seven-day average test positivity rate in those cities never climbed above 13 and 12 per cent, respectively.
The south west zone has the highest measure of the metric right now, with a seven-day average of test positivity of 45 per cent.
Dr. Saqib Shahab, Saskatchewan's chief medical health officer, said the province expects to see positivity rates continue to climb in the weeks ahead.
"It's one or two weeks ahead in Regina, Saskatoon, and then, you know, it will likely peak in a week or two and then start coming down," he said at a Provincial Emergency Operations Centre update this week. "Then in a week or two, it will start peaking in rural and northern parts of the province.
"Despite our best efforts, many of us are getting exposed."
The provincewide test positivity is also high, with the seven-day average sitting at 33 per cent as of Wednesday.
Test positivity is a good metric to understand how prevalent COVID-19 is in Saskatchewan, but it's not everything.
Experts say if a province isn't testing enough people and people aren't seeking out tests, the test positivity rate will not be a true reflection of COVID-19's spread.
The rate also does not include rapid test results, which are normally done by individuals and not reported to officials.
It points to a bigger issue, according to Muhajarine.
The epidemiologist said every piece of data that is being looked at must now come with an asterisk alongside it.
Even if the provincial government wants to reopen PCR testing to the wider public, the resulting data may no longer be accurate, he said.
"I think once it is, it is gone. It is not retrievable. We cannot do retroactive testing on someone, you know, because that time has gone."