Ontario's COVID-19 wastewater data shows infection rate headed in 'the right direction'

In this file photo, COVID-19 antigen home tests indicating a positive result are photographed in New York, April 5, 2023. (AP Photo/Patrick Sison, File)

A snapshot of Ontario’s COVID-19 wastewater data shows the rate of infection in the province is dropping after a holiday spike.

According to Ontario Public Health’s last update, the province’s so-called wastewater signal was 0.71 as of Feb. 2 -- the lowest level since Sept. 14. In the second half of December, during what some public health experts described as a wave of infection, the marker reached 2.29.

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“We had a spike in wastewater detection of COVID, throughout December, and in January, and then it started to decline after the holiday season and certainly continues to head in the right direction,” University Health Network Infectious Disease Specialist Dr. Isaac Bogoch told CTV News Toronto on Monday.

The presence of COVID-19 in wastewater appears to be shrinking in every region surveyed by Ontario Public Health, with the exception of northwest Ontario where the signal is actually trending upward to 1.28.

While promising, wastewater data only shows a part of the province’s COVID-19 picture, Bogoch warns.

“If the question is: how are we doing with COVID? The answer is: you've got to look at multiple metrics, right? Because no one metric is perfect, including wastewater,” he explained, adding that factors like hospitalizations, test positivity and number of tests completed help to add context.

Although Ontario no longer tests for or reports on COVID-19 infections as it did during 2020 and 2021, the publicly available data shows other key indicators are trending down as well.

Ontario's COVID-19 wastewater data is seen in this image. (Public Health Ontario)

As of Feb. 3, there were 81 people in hospital with the virus compared to 396 hospitalizations at the beginning of December. Meanwhile, test positivity is dropping from a recent high of 43.1 per cent in late November to 21.5 per cent in the last week of January.

Even though the data is “far from perfect,” Bogoch says piecing it all together does help show how prevalent COVID-19 is in the province, especially at a time when testing and reporting is not nearly as widespread as it once was.

“But when you put all the pieces together, even though they are imperfect bits of data, it paints a picture, and that picture is COVID is still here. COVID is still a problem. But we're seeing much less COVID circulating now than what we were during the holiday season,” he said.