Coronavirus: COVID-19 Wasteland: Look for clues to a pandemic in the sewer

Ottawa-Ottawa’s public health authorities look to regular markers such as positive tests, hospitalized patients, and outbreaks when trying to determine if city regulations need to be tightened. But they are also one of the few in the country to get clues from the city’s sewers.

The use of urban sewage to look for evidence of the virus behind COVID-19 is part of a rapidly expanding science. The virus is often excreted in human excrement before the patient realizes that he or she is ill.

Prior to COVID-19, there was virtually no wastewater testing initiative in Canada, but there are currently more than 20 universities studying this method. Meanwhile, at least seven cities and the Northwest Territories have already publicly reported on the consequences of wastewater.

The Ottawa project, a joint effort between the University of Ottawa and the locally based Pediatric Health Research Center CHEO, was the first project to report daily data.

As some of Ottawa’s social media sites call it, the rising “poop signal” is almost always the day to warn that the incident is about to surge.

It happened recently during Easter. Rob Delatra, a professor of civil engineering at the University of Ottawa and one of the brains behind the city’s COVID-19 wastewater project, said the data for the long Easter weekend were not good.

“They’re really high, datapoints,” he said. “So that’s not the best story, but I think it reflects what’s really happening in the city.”

Sure enough, the number of Ottawa cases went from about 150 to 170 per day last week, and has recently exceeded 250 per day several times.

Bernadette Conant, CEO of the Canadian Water Network, said to coordinate and track all the work that began to emerge last spring when the relationship between COVID-19 and wastewater first received serious attention. He said the organization had established a coalition.

“The very immediate goal is whether it can help Canada’s public health,” she said.

“I can’t quantify it, but I can say,” Yes, it’s worth it. ” “

In Ottawa, the signal is quoted by real epidemiologists and armchair epidemiologists alike.

According to Delatra, researchers are working closely with Ottawa Public Health and report the number daily to Dr. Monil Taha, Deputy Chief Public Health Officer in the city.

“He uses our wastewater data in a daily report to the (epidemiology) group of Ottawa Public Health. When we were late, he emailed us,” Hey everyone, come on. Yes, it’s all. ” OK, “said Delatra.

The city’s chief public health officer, Dr. Vera Etches, tweeted the signal data to inform Ottawa that it was time to sit down. In early March, Etches said in a media interview that wastewater was telling her that a third wave was approaching us.

But the system is not absolutely certain. When Etching was issuing her warning, the poop signal was falsely suggesting that things were much better.

“I saw the snowmelt definitely affect the signal,” said Delatra.

The combination of factors around the spring melt, which means about two weeks in mid-March, all data became unstable, diluted with excess water, affected by excess salt and sand, and some during the spring. Don’t overwhelm water treatment plants delayed by the city’s new system of curbing wastewater.

Mr Delatra said things are on track now.

“What’s great is that it’s just a small little lab where we do this,” he said. “I think I did 4,000 tests a day in Ottawa and got that line. I got one sample, one small little lab and I got a very similar line. This shows the power to use wastewater. “”

It also tells the story of a variant of concern. The team has developed a new test to look for the first B.1.1.7 mutation identified in the United Kingdom.

Ottawa has screened more than 1,600 variant cases so far, but it can take days, if not weeks, to see which particular variant is working.

Wastewater signals indicate that more than half of the viruses in sewage are b.1.1.7 variants.

Researchers have completed tests to look for at least one other variant so far and will share their efforts with other cities. The Peel region of Vancouver, Calgary and Ontario is one of seven other municipalities implementing wastewater COVID projects.

According to Conant, the idea for the COVID-19 test came from a Dutch project that shifted its focus to testing SARS-CoV-2 last winter after already testing the waste of other viruses.

An online portal that tracks surveys conducted by the University of California, Merced, has 248 universities studying this idea, 70 “dashboards” in 50 countries around the world, and regular COVID-19 wastewater. Data is open to the public.

The portal, called “COVID Loops 19,” also has its own Twitter account (and the poop emoji that occurred in the case of the new coronavirus).

Connant said the future of the study is still developing, but it is expected to play a valuable role in questioning trends and outbreaks in high-risk areas such as long-term care facilities and prisons.

This report by The Canadian Press was first published on April 11, 2021.