Ottawa researchers 1st in country to develop test to find COVID-19 variant in wastewater

·3 min read

Ottawa researchers say they have become the first in the country to develop a test that detects a variant of the COVID-19 virus in wastewater — recently detecting it in a sample from Barrie, Ont.

Researchers across the country have already been testing wastewater for traces of SARS-CoV-2, the virus responsible for the respiratory illness. Many of those infected shed the virus through their feces, even if they don't have symptoms, according to researchers.

But the team at the CHEO Research Institute in Ottawa said this is the first time the variant first reported in the U.K. was found in a sample of wastewater.

"Scientists, we have very few eureka moments and I guess that's one of them," said Tyson Graber, associate research scientist and co-lead investigator on the wastewater monitoring project.

Francis Ferland/CBC
Francis Ferland/CBC

The test can only detect the variant first detected in the U.K., but not those found in South Africa and Brazil. Graber said researchers are working to develop wastewater test for those variants as well. The team has been meeting with the Public Health Agency of Canada through the National Microbiology Laboratory in Winnipeg weekly.

The Simcoe Muskoka District Health Unit confirmed the variant was detected in a wastewater sample from Barrie. As for Ottawa, Graber said the most recent data from mid-January shows the variant hasn't been detected in the city's wastewater yet. More recent data from tests on Friday have not returned yet.

To be shared with rest of country

It's also still unclear just how sensitive this test is.

Graber said it's possible it could take up to 100 cases in Ottawa before researchers "can confidently say that there is detection through this wastewater test."

Francis Ferland/CBC
Francis Ferland/CBC

"A million-dollar question right now in the field is trying to correlate the case numbers in the city or any surveyed area with the wastewater signal, and we still don't really have a good idea of how to do that," Graber said, adding it will become even more difficult with the new variant.

Graber said the results of the research will be shared with laboratories around the world.

Troy Day, a member of the Ontario Modelling Consensus Table and a mathematician at Queen's University in Kingston, Ont., said the test will also give researchers a clearer picture of "where we currently stand" when it comes to the presence of more transmissible variants.

"Any surveillance that we can come up with ... is going to be beneficial," he said.

Data can guide public health officials

The data collected from this new test can help inform Ottawa Public Health's decisions, whether restrictions should be tightened or loosened, Graber said, and could hopefully give some lead time before the more contagious variant enters the community.

"I think at this point in time, [it] is not a question of if it's going to happen. It's a question of when and so the earlier we can get this information into the hands of public health officials, the better," he said.

He said the plan will be for directions for this test to be made public next week.