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'We're clearly in a wave': Ontario's COVID-19 wastewater signal is more than double what it was at this time last year


COVID-19 viral activity in Ontario as measured by the province’s wastewater signal is now more than double what it was at this time last year and health officials are raising concerns about what could be a challenging few weeks heading into the holidays.

The latest data, released on Thursday afternoon, shows that Ontario’s wastewater signal now stands at 2.1, up from 2.04 at this time last week.

It was 0.98 on the same day in 2022.

The data, maintained by Public Health Ontario, suggests that this is the highest wastewater signal the province has recorded in more than a year. However, a similar dataset maintained by the now defunct Ontario Science Advisory Table shows that the number hasn’t actually been this high for at least two years.

“There's a real consistency about what's happened now — that we're clearly in a wave that started towards the end of the summer, early fall,” Dr. Fahad Razak, an internist at St. Michael’s Hospital and the former scientific director of the Ontario COVID-19 Science Table, told in an interview this week. “There was a hope that it had started to plateau by late September, early October. But in fact, unfortunately, it's gone the other direction and continues to rise quite steeply.”’

While the provincewide wastewater signal currently stands at 2.1, the number varies across different regions.

In the GTA, the growth in viral activity has been less pronounced with the number now standing at 1.68 compared to 1.09 one year ago.

But in the central west region of Ontario, which includes communities immediately outside of the GTA, the number is at 3.65, more than five times what it was a year ago. In eastern Ontario it is 2.78, nearly three times last year's number.

The wastewater signal, of course, isn’t a perfect reflection of the overall level of COVID in a given community.

But Razak says the number of positive PCR tests among those who still qualify for the test is also at a one-year high, as is the number of people in hospital testing positive for COVID-19.

For many people, the evidence of an increasingly active respiratory virus season is evident around them as well, he said.

“I think that the anecdotal experience of probably everyone in this province is that right now, you know a lot of people who have been infected, whether it's at work, whether it's in school, whether it's in your family, I think this is a constant refrain,” Razak says. “And I can say we're certainly seeing this in the healthcare system as well. People who are working, they’re getting sick. So you know, I think we have everything pointing in the same direction.”

Speaking earlier this week, Ontario's Chief Medical Officer of Health Dr. Kieran Moore said the virus is on the upswing, whereas this time last year it was declining.

“I'm sorry to say we still have significant COVID activity across Ontario — roughly 1,800 people in hospital, 100 needing intensive care,” Moore told CP24.

Moore said that while 1.8 million people have gotten the latest vaccine, that represents just 13 per cent of the eligible population.

Importantly, the latest vaccine has seen just a 40 per cent uptake from those who are 65 and older.

“And yet there's roughly 800 Ontarians over 80 and 700 Ontarians over 70 in hospital today with COVID. So that's a key population we need to maintain immunity against COVID,” Moore said. “Natural immunity against the virus fades with time and so does immunity from the vaccine and those populations really need to stay up to date with their immunizations.”

Dr. Kieran Moore, Ontario Chief Medical Officer of Health, speaks at a press conference at the legislature in Toronto on Monday, April 11, 2022. THE CANADIAN PRESS/Nathan Denette

The fact that more people are not requiring ICU care despite the sharp uptick in transmission around the province is evidence, Razak says, that the vaccines have been effective at preventing more serious illness in many people.

“Even though there has been a rapid rise in the number of people in hospital with COVID, the number of people in the intensive care unit has barely risen. And so that is good news,” Razak says. “And we should recognize why that has occurred. That has occurred because of immunity. And it's the immunity that the vast majority of the population has from vaccines, and infections, and both vaccines and infections combined, which we call hybrid immunity. There's a really important lesson from that, which is that keeping your immune protections up works.”

He adds that aside from COVID-19, influenza and RSV, there are many other respiratory viruses circulating at the moment.

“There is also probably a lot of overlapping viral infections happening right now, where you get infected with one thing, you start to get better, you get infected with another virus. And so you have these kinds of waxing and waning symptoms.”

He said the tools that we used over the past few years to combat infection are still useful for helping to reduce the spread of COVID and other respiratory viruses, which is especially important for older, more at-risk populations, as well as to protect the health-care sector. Those tools include masking in crowded settings, rapid tests and vaccinations.

While none of the tools are perfect, Razak acknowledges, used together they are much more effective than doing nothing.

“As someone who works in the hospital sector as a frontline physician, this winter is going to be very challenging for us again,” Razak says, pointing out that staffing is still a challenge and that the real crush of influenza and COVID-19 cases has not really started.

COVID-19 and flu vaccines are now widely available at pharmacies, doctors’ offices, and local vaccination centres.

Moore said this week that transmission is expected to peak around the holidays. With that in mind, doctors are saying that people can act now to reduce spread to loved ones as we head into the holidays.

“I would say we've had three very tough holiday seasons now in a row. Let's do whatever we can to make this one better,” Razak says.

That includes steps, such as masking in crowded places, testing and staying home if you're sick.

“And then move on with your life and enjoy your holidays because people have had a very difficult time. Let's make this the best holiday possible.” Top Stories

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