Canadian scientists track new COVID variants in aircraft wastewater
As Canadian public health officials question China’s transparency in sharing COVID-19 surveillance information, scientists are stepping up testing of jet sewage to try to come up with a solution. early warning of potential new variations.
On Friday, Vancouver International Airport will join Toronto’s Pearson International Airport in taking stool samples from plane toilets to identify coronavirus variants and possible sub-variants that passengers and crew may have. bring into Canada.
Dr Guillaume Poliquin, vice president of Public Health Canada’s National Microbiology Laboratory, told The Canadian Press: “A sentry system for new variants – that’s really where we see it. added value of airport testing.
Where will wastewater testing take place?
Sampling will take place at two of Canada’s busiest airports: Pearson International in Toronto and Vancouver International Airport.
The Public Health Agency of Canada (PHAC) has been working with university scientists to examine wastewater from incoming planes, as well as terminal buildings, at Pearson since January 2022. Waste from planes arriving from domestic and international destinations are mixed together, said Lawrence Goodridge, a University of Guelph professor who was one of the researchers.
That will continue, but PHAC is adding a pilot project to separately test wastewater from aircraft coming from China or Hong Kong.
Trevor Boudreau, the airport’s director of government relations, said on Friday the PHAC and the BC Centers for Disease Control will begin testing wastewater from “latrines” from planes at the International Airport. Vancouver, no matter where they come from.
Then, in the coming weeks, the researchers will begin a pilot study similar to Pearson’s separate test samples from planes arriving from China and Hong Kong, Boudreau said.
“You know, airports really represent a huge percentage of people — many of them international tourists coming to the country,” Goodridge said.
“The variations that have caused major public health concern to date have all originated outside of Canada. So it’s a great way to understand what’s coming and that data can then be used used to make public health decisions.
Why are planes from China and Hong Kong tested separately?
There has been an outbreak of COVID-19 disease after the Chinese government lifted strict restrictions. 31, PHAC said China had not provided enough “viral epidemiology and genomic sequencing data” on those cases.
That includes information about what variations are circulating and any potential new variations emerging.
“What we’re doing here is taking it a step further (wastewater testing) and seeing if we can achieve more accuracy by taking samples directly on the plane,” Poliquin said. .
“We will then be able to compare that data… with data from the pooled samples to see if it really adds significant value, what kind of additional information does it give us? “
How does wastewater testing work?
Goodridge said what came out of the plane’s toilet was a “sewage soup” with strains of the virus and variations from hundreds of thousands of people.
Trucks transport wastewater to a central facility where scientists take samples.
The first part of the process is to separate the solids and liquids in the waste and remove any “contaminants” – such as fibers and chemicals – that could interfere with the analysis, Poliquin said.
The “clean sample” is then run through an analysis of the genetic material – specifically the RNA from the virus – that is present. That process, called “genome sequencing,” uses computer algorithms to find COVID-19 variants.
Genome sequencing allows scientists to not only find variants and sub-variants with which they are familiar, but also to see anything that seems unusual or new.
That’s when the PHAC can look at any particular mutations and compare them to what they’ve observed clinically, such as the variations they’ve found through PCR testing. They can also compare the findings with data they receive from other countries on what variations are circulating.
A new Omicron variant that PHAC is monitoring is now called XBB.1.5. Centers for Disease Control and Prevention (CDC) data from the last week of December shows that this variant accounts for about 40% of COVID-19 cases in the US, and the UK is also reporting an increase. increase.
As of Wednesday, the agency was aware of 21 XBB.1.5 cases in Canada and said it was “currently considered sporadic,” the agency said in an email.
Where else is wastewater testing used?
Rob Delatolla, an environmental engineer at the University of Ottawa, says there are more than 175 sites that conduct wastewater testing for COVID-19 in Ontario alone. Sewage testing helps inform public health about the amount and type of COVID that is spreading in cities and towns, as well as vulnerable neighborhoods, First Nations, and hospitals.
COVID-19 has spurred a significant increase in wastewater testing, Delatolla said, and it is now also used to detect influenza and RSV.
Goodridge, from the Pearson Airport wastewater testing project, specializes in food microbiology and used wastewater monitoring to detect foodborne illnesses prior to the COVID-19 pandemic.
Historically, it was also used to detect polio, he said.
Goodridge says wastewater testing at airports and planes has proven invaluable.
“I would like to see this extended to other major international airport(s) in Canada,” he said.
“We’re seeing what’s coming to the country, you know, in real time.”
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