Scientists aim to measure coronavirus in wastewater
City wastewater could hold hints on where COVID -19 outbreaks are happening in Calgary, according to researchers at the University of Calgary.
A group of U of Calgary scientists, along with Alberta Health Services and City of Calgary officials, will begin testing wastewater samples from throughout the city for traces of SARS-COV-2, the virus that causes COVID-19.
“As soon as the virus leaves the body, it’s starting to degrade,” said Casey Hubert, a U of Calgary biological sciences associate professor helping to lead the project.
“The premise of our work is that though the virus might not be infectious in the wastewater, we can still detect it and trace it in a way that’s quantitative.”
The study will be able to identify when a sample has a high concentration of SARS-COV-2, Hubert said, which can then be used to reach conclusions on which areas of Calgary face more severe outbreaks.
According to Michael Parkins, an associate professor at U of Calgary’s Cumming School of Medicine who is also involved with the project, wastewater analysis can identify pre-symptomatic or asymptomatic cases of COVID -19, meaning the data could uncover clusters of cases before those outbreaks are reflected in official case counts.
Then, Parkins said, Alberta public-health officials could use information about these outbreaks to target resources such as testing to those areas of the city and potentially introduce hyper-localized restrictions.
“Those interventions would minimize the social and economic disruptions that we’ve witnessed from our aggressive policies so far,” he said.
The samples will be collected at Calgary’s three wastewater sites, as well as at earlier stages of the wastewater process. Norma Ruecker, the microbiology lead with Calgary’s water department, said it’s possible to pinpoint the specific regions where waste comes from.
“At any manhole we lift and collect a sample at, we would be able to map exactly what the geographical collection was,” Ruecker said. “The sewer collection system doesn’t overlap neighbourhood communities as we know them, but we would be able to identify for any sample … basically, what toilets have been flushed at what addresses.”
Ruecker also stressed that the virus found in wastewater is a “dead virus” and that there is no risk in handling samples.
As a doctor, Parkins has seen dozens of patients with the coronavirus, an experience he said illustrates why it’s vital to get the best possible understanding of where cases are concentrated, especially if an anticipated second wave of the virus emerges.
“Make no mistake: the cases are going to come. Our goal is just to minimize the rate they do come,” Parkins said. “I suspect we’re missing a great deal of cases in younger people and in children who are propagating the infection to those at the greatest risk.
“We’ve only seen the tip of the iceberg. We want to get to the base.”
The project was funded through a half-million-dollar Canadian Institutes of Health Research grant, supplemented with researchers’ funding from U of Calgary and the province.
Hubert says it’s similar to studies done elsewhere in the world, including in Italy, where research found traces of the novel coronavirus in wastewater in December, months before it was officially detected in the country.
The methods researchers will use could potentially also find traces of the virus in historical samples, according to Hubert.