Wastewater samples prove everyone infected with COVID-19 releases a little of the rapidly evolving disease, according to researchers at Western University in London, Ontario.
While researchers say the wastewater is not known to be infectious, it does show that COVID-19—the root cause of 2.7 million deaths worldwide—is widespread even in communities with low confirmed case rates.
“What ends up in the wastewater is degraded and is very unlikely to actually infect people, we believe,” said Christopher DeGroot, professor at Western Engineering. “That said, wastewater surveillance can serve as an early warning system for COVID-19 outbreaks in our communities—making it vitally important to public health and safety.”
DeGroot is leading a study collecting wastewater samples from a number of strategic locations in London, and analyzed at Western’s Imaging Pathogens for Knowledge Translation (ImPaKT) Facility.
Wastewater surveillance is a proven method for mapping community infection rates when result wait times for COVID-19 nasal swab tests are lengthy or even delayed.
This testing initiative by Western is a continuation of sampling collected by University of Windsor, which was launched in November 2020 with weekly local collection and testing, and ramping up recently to three times a week.
“We’re detecting leftover RNA (ribonucleic acid) fragments in the wastewater that come from infected individuals,” said DeGroot. “Those fragments are readily concentrated and detected, but don’t pose a public health risk.”
Ribonucleic acid, which can be used for vaccine development, carries genetic information in certain viruses, especially in retroviruses like HIV.
DeGroot says results from wastewater samples which cover asymptomatic and symptomatic infected people should precede reported cases and clinical data collected by the Middlesex-London Health Unit at least by a few days, maybe even a week, serving as an effective warning sign for future outbreaks in the city.
“We’ll be watching very closely for any increase in the viral load showing up in the wastewater, especially as we start to reopen the city and vaccines are being distributed,” said DeGroot. “We think this is a really valuable tool.”
Western is also working on similar wastewater and environmental projects related to COVID-19 with Schulich, the Ivey Business School, Western’s Human Environments Analysis Laboratory (HEAL), the Institute for Chemicals and Fuels from Alternative Resources (ICFAR), and in collaboration with Trojan Technologies and USP Technologies in London.