Using wastewater to track COVID-19 variants of concern around the globe

London, Ont. -

Researchers at Western University are analyzing wastewater samples from around the world to track the spread of COVID-19 and its variants.

In December of 2020, Professor Eric Arts and Assistant Professor Chris DeGroot at Western University’s Schulich School of Medicine and Dentistry began sampling water in Southwestern Ontario for traces of the COVID-19 virus.

“Wastewater sampling, what we’ve found, and many people have shown, is it really provides a very accurate estimate of how many cases there are in the population,” says Arts.

That led to expanding the scope internationally in places like Venezuela and Uganda, where samples were taken from streams where open sewers drain into the watershed.

“What we’re doing right now is very important for Ontario and all around the world,” says Arts. “One of the big initiatives we’re working on with the government, both federal and provincial, is to try and find better ways of getting an early warning, early detection system for when new variants come into the country.”

The water that is collected -- no matter if it is Ontario or in distant locations like Uganda -- is shipped to be analyzed at Western’s Imaging Pathogens for Knowledge Translation (ImPaKT) facility. This is where the RNA can be extracted and tested for the presence of SARS-CoV-2 and its variants.

“We’ll be able to detect a multitude of viruses in wastewater, and be able to report back on the overall prevalence in the community,” says DeGroot.

In Ontario, testing community wastewater may become a more effective way of determining the prevalence of the virus in the community as more people are vaccinated and may not show symptoms.

“You’ll have more mildly symptomatic cases that may not proceed to get tested, and we’re able to get a sort of community view, on the whole of what’s going on in London in terms of the state of the pandemic,” says DeGroot.

The research team hopes that beyond the COVID-19 pandemic, this could be used to detect other viruses in wastewater, to get an early warning of future outbreaks and epidemics.