Coronavirus levels in wastewater rise 'significantly' in Ottawa

Recent wastewater data in Ottawa confirms what many suspected — the city is swimming in yet another wave of COVID-19 — but modelling suggests it won’t be as bad as the last one, experts say.

Current average is more than 4x higher than before Omicron surge in December 2021

Tyson Graber is the associate research scientist and co-lead investigator on Ottawa's coronavirus wastewater monitoring program. (Francis Ferland/CBC)

Recent wastewater data in Ottawa confirms what many suspected — the city is swimming in yet another wave of COVID-19 — but modelling suggests it won't be as bad as the last one, experts say.

The average level of coronavirus in the city's wastewater has risen "significantly" over the past 10 days of available data, according to a local researcher who said similar trends are seen across Ontario. 

"How big that wave will be, we don't know yet … we're more concerned right now with that increase in signal," said Tyson Graber, co-lead investigator of the COVID-19 wastewater project in Ottawa.

While the nation's capital is nowhere near the peak of the first Omicron-driven wave in early 2022, Graber said people should take precautions to protect themselves and the community.

"Nothing has changed just because the government has decreed that masks are no longer required," he said.

"Using this data, you as an individual has to make that decision of whether or not you would like to be masking in certain areas, or whether you should go to that party on Friday night."

WATCH | More on COVID-19 levels rising in wastewater:

COVID-19 levels rise in wastewater, signalling a potential new wave in Ottawa

3 months ago
Duration 1:19
Tyson Graber, co-lead of Ottawa’s COVID-19 wastewater monitoring project, says the level of COVID-19 in the city’s wastewater has risen steadily in the past week, marking the start of another wave of infections.

Mini-wave predicted

This mini-wave is not a surprise for Dr. Doug Manuel, a physician and senior scientist at The Ottawa Hospital, who like other health officials predicted the increased transmission as restrictions were lifted and the Omicron BA.2 subvariant picked up speed.

The current level of coronavirus in Ottawa's wastewater is similar to what was seen on Christmas Day 2021 and the first week of February 2022.

It is more than four times higher than before the initial Omicron surge in late December and more than double what it was on March 10, but Manuel is optimistic because modelling suggests numbers won't rise as rapidly as previous waves.

"We're not going to see those high levels even in kind of the worst situation or an unlikely situation," he said.

Manuel does caution, however, that factors such as individual behaviour has made modelling more difficult to build.

"It will depend on how many people take their masks off and how much mixing there's going to be."

WATCH | Why modelling COVID-19 spread is now more difficult:

COVID-19 modelling in uncharted territory as restrictions ease

3 months ago
Duration 1:18
Doug Manuel, senior scientist at The Ottawa Hospital, says modelling the future of COVID-19 is becoming more difficult as scientists try to account for relaxed restrictions and variations in people’s behaviour.

In a written statement, Ottawa Public Health said it would continue to monitor key COVID-19 indicators and work with Dr. Kieran Moore, Ontario's chief medical officer of health, to assess which options could be implemented in Ottawa if necessary.

The health authority also encourages everyone who is eligible to get vaccinated to do so, and to continue wearing a mask in indoor settings where physical distancing may be difficult.