CoVaRR-Net sees great promise in wastewater surveillance

Wastewater surveillance detects infections at their earliest stages

Many people are infectious before they have symptoms. People infected with SARS-CoV-2, the virus that causes COVID-19, release the virus in their stool. By measuring the levels of virus within genetic material in wastewater, public health officials can assess trends and variations in local SARS-CoV-2 infection without physically testing individuals.

Because of limited PCR testing, the data on the spread of SARS-CoV-2 is becoming limited; wastewater surveillance offers an opportunity to provide a reliable snapshot of COVID-19 rates everywhere it’s monitored.

“It gives you a population-based estimate of what’s going on in your community,” says Doug Manuel, Director of CoVaRR-Net’s Wastewater Surveillance Research Group. “The sewer system is like a window into the health of the community.”

CoVaRR-Net is helping the practice go national

CoVaRR-Net’s Wastewater Surveillance Research Group brings together Canadian wastewater and environment investigators from universities across Canada and the National Microbiology Laboratory. CoVaRR-Net is part of a community of approximately 200 researchers and public health staff at over 250 testing sites, including in the Canadian North where wastewater has become a key surveillance tool. CoVaRR-Net’s researchers have also created a data model for wastewater and public health surveillance that is used both in Canada and over 27 countries worldwide.

Dr. Manuel sees promising data emerging from the active sites in Canada, noting that wastewater surveillance has confirmed the lower infection rates currently taking place. “You can see through this published data that the prevalence of the virus is diminishing.”

Wastewater surveillance is cost-effective

Studies have found wastewater surveillance to be a small fraction of the cost of individual PCR testing. This is good news here in Canada, as well as in the US and Europe, but it can also provide much-needed viral data to low-resourced countries that see individual testing costs as prohibitive.

“By filling important gaps in the surveillance toolbox, wastewater testing enables broad-based, sustainable, early, and equitable detection of COVID-19 spread,” read a recent World Bank report, which Dr. Manuel helped author.

Wastewater surveillance is just as effective at identifying the SARS-CoV-2 variants

Wastewater surveillance and PCR testing offer equally effective detection of SARS-CoV-2 variants, according to a CoVaRR-Net-funded pre-print paper that looked at a large sampling in Montreal, Quebec City and Laval. The study retrieved wastewater samples between March 2020 and July 2021 and detected variants comparable with the clinical samples – even the dates of the outbreaks matched. The study also showed the potential to detect emerging variants.

Dr. Jiannis Ragoussis, one of the paper’s senior authors, a member of CoVaRR-Net’s Wastewater Surveillance Research Group as well as CoVaRR-Net’s Viral Genomics & Sequencing Pillar Lead, says having an early warning system like this helps public health authorities alert affected communities, allowing them to take measures to decrease the spread of the virus. “Having an extra two to three days to prepare can be critical,” he says. Dr. Ragoussis is currently working on a paper with CentrEau members Dominic Frigon and Jesse Shapiro that details a wastewater surveillance study in which Omicron was detected in the neighbourhood of Montreal North before any individual was clinically identified as Omicron-positive.

Wastewater surveillance can also detect toxics and pathogens and is also useful for future pandemics

Dr. Peter Vanrolleghem, another member of CoVaRR-Net’s Wastewater Surveillance Research Group and the Canada Research Chair on Water Quality Modelling, sees wastewater surveillance as a tool that goes beyond detecting COVID-19 and its variants. “We can detect micropollutants and pathogens, such as pharmaceuticals, illicit drugs or antimicrobial resistance in a community. A Canada-wide wastewater surveillance infrastructure will not only be of use in this current pandemic, but also can help keep our communities safe from future pandemics and other threats to our health.”

The potential for this kind of reporting is great

Dr. Amy Hsu, CoVaRR-Net’s Data Platform Director, imagines the potential of increasing the number of sites in Canada and sharing more wastewater surveillance data from coast to coast to coast. “The data infrastructure to monitor active cases of SARS-CoV-2 – standardizing the way labs across the country and the globe collect, organize and report data – has implications beyond this pandemic. This would be a significant step forward, making wastewater surveillance a part of global public health.” Hsu and her Data Platform team at CoVaRR-Net are working on just that: a coordinated and streamlined database, so that communities using wastewater surveillance can share data readily.

Manuel agrees that wastewater surveillance should be part of global public health – Canada being no exception – and sees the groundwork as urgent. “We need cross-country infrastructure, we need it in the hands of public health, and we need it to be publicly available for us to interpret.” His Wastewater Surveillance Research Group at CoVaRR-Net is trying to help make that happens.

Learn more about CoVaRR-Net’s Wastewater Surveillance Research Group

To arrange an interview with Dr. Doug Manuel, Dr. Jiannis Ragoussis, Dr. Peter Vanrolleghem, or Dr. Amy Hsu, please contact:
media@covarrnet.ca