Ontario ending wastewater surveillance program which tracked COVID-19 infection

Specimens to be tested for COVID-19 are seen at LifeLabs after being logged upon receipt at the company's lab, in Surrey, B.C., Thursday, March 26, 2020. THE CANADIAN PRESS/Darryl Dyck

Ontario is quietly winding down the wastewater surveillance initiative which provided scientists with crucial data about infection rates in the province during the COVID-19 pandemic.

In an email, a spokesperson for the Ministry of Environment, Conservation and Parks said the province is making the move "to avoid duplication" as the federal government also conducts wastewater surveillance across Canada and is moving to expand its sampling to additional sites in Ontario.

"Moving forward, the Ministry of Health will be working with the Public Health Agency of Canada on a data sharing agreement to ensure that the province can continue to analyze Ontario specific wastewater data," the ministry said.

Wastewater surveillance has emerged as a crucial tool for monitoring the level of infection in the population.

The decision to end provincial data collection sparked a sharp response from Ontario Green Party Leader Mike Schreiner Wednesday.

"We need this kind of detailed information to detect emerging threats, monitor community spread and make informed policy and public health decisions," Schreiner said in a statement. "Given the scope of Ontario’s wastewater testing program, the expansion of federal testing into the province is insufficient to maintain the standard we have established."

It was not immediately clear how frequently the federal government plans to test or at how many sites.

Speaking with CP24.com, Dr. Fahad Razak said that while the move is a shift from how things have been done, there's no indication so far that the data won't be comparable.

"As long as it's timely and comprehensive, I don't see any reason why it should be provincially managed, as opposed to federally managed," said Razak, an internist at St. Michael’s Hospital and the former scientific director of the Ontario COVID-19 Science Table.

"It is not unreasonable for the federal government to take over a centralized approach to testing," Razak said. "I would say from a public health perspective and a scientific perspective – and I think what the public should want – is that the availability of the information still remains timely and comprehensive, so that in future waves people can make decisions, especially the individualized decisions that people are now facing."

During the pandemic, when there was sometimes a lack of access to tests or fewer people getting tested, wastewater data became a key metric of how much viral activity was present in the population. The data was subsequently used to help track whether the province was moving into or emerging from a wave of infection.

The province has been doing weekly wastewater testing in seven regions, including the Greater Toronto Area. Samples have been collected from across 59 wastewater treatment plants, pumping stations and sewersheds in all 34 public health units. Public Health Ontario has then analyzed the data and made it publicly available online.

The program was based on the original work of the Ontario COVID-19 Science Advisory Table.

Public health experts have lauded wastewater surveillance as a useful new tool for tracking the prevalence of COVID-19 and other infections in the population.

Razak said that the winding down of the program marks yet another milestone in the emergence of the province from the pandemic.

"I think we can also see this as the end of an era," he said. "This was a data point that many people paid very close attention to for the last few years. And I think what we're seeing here is in a receding of that kind of attentiveness, which makes sense. This is not the crisis that it was before."

That said, he added that the technology remains incredibly useful for public health officials, as well as anyone who is at higher risk and is trying to gauge their risk level in an area.

He pointed out that wastewater data has also been used recently to track polio, an early RSV season and other emerging and changing pathogens in different regions.

"So this is really, I think, part of the future of surveillance technology," Razak said. "We need to ensure that it continues because again, we don't know what the next big crisis will be or when it will occur, but having this infrastructure up and running will allow us to respond more effectively."