Wastewater testing a 'potentially powerful tool' in tracking the flu, epidemiologist says

Researchers at the University of Ottawa are using the wastewater testing strategy that has helped track the ebbs and flows of coronavirus and applying it to influenza.

Patrick D'Aoust, a PhD candidate in the faculty of engineering, said the idea came from one his colleagues, Elisabeth Mercier, and the success of the wastewater testing used to track levels of coronavirus in Ottawa.

"She said, 'You know we're looking [for] COVID-19. It's an RNA virus. Why don't we just start looking at other RNA viruses?" D'Aoust said.

While wastewater testing for influenza has been done in other parts of the world, this is the first time the University of Ottawa has undertaken the endeavour. 

Mercier, a master's candidate in engineering at the university, said the hope is this will help Ottawa Public Health in managing future outbreaks. 

She said early warning can help manage pressure on the health-care system, by giving a picture of what is going on underneath the surface. 

"We're just adding some precision, some layers of data that those public health units can keep monitoring," she said.

Dr. Raywat Deonandan, an epidemiologist and associate professor at the University of Ottawa, said there are "at least a couple" of studies showing wastewater testing is effective at finding influenza.

"And it might be effective in finding other kinds of diseases as well, so long as that virus resides in human feces, as many do," he said.

"I think it's a potentially powerful tool." 

Like a weather app?

D'Aoust said that this will help people better prepare for viral outbreaks in their communities, akin to the way people check a forecast.

"I think the way this will be is like the weather app on your phone." 

He said this testing system could serve as a measuring index for viral diseases like COVID-19 or influenza, which could alert people to start taking certain precautions, like wearing a mask.

With more resources and more study, you can increase the resolution and the power of this technology.- Raywat Deonandan, epidemiologist

Robert Delatolla, professor of civil engineering at the University of Ottawa, said COVID-19 laid bare the inequities in how diseases affect different communities.

By testing wastewater, they can help identify which communities need more help. 

"When we were monitoring influenza here in Ottawa, we not only saw differentials between the amount of COVID, we saw the flu in those same communities have a distinct pattern and a higher load and greater number of people being sick," he said.

Deonandan said this method can be very effective in identifying hotspots.

"If that testing is done rigorously and consistently, in some cities, you can almost get resolution down to the given building. If you're clever, maybe even to the floor of an apartment building," he said.

"With more resources and more study, you can increase the resolution and the power of this technology."

While the lab at University of Ottawa is also testing the water for monkeypox, D'Aoust said they haven't detected a high rate of positivity yet.

"But we're going to be very careful and we're going to keep testing at a high frequency."