Under the microscope: Looking at B.C.'s wastewater surveillance for viruses

Akshay Kulkarni · CBC News

· Posted: Mar 17, 2025 10:00 AM EDT | Last Updated: 7 minutes ago

Testing wastewater for diseases and viral enactment gained prominence during the pandemic, but scientists are acrophobic that backing for specified enactment could beryllium threatened.

Monitoring wastewater for pathogens — and adjacent illicit and medicine drugs — was astir for decades earlier the pandemic, but the method of estimating microorganism levels gained nationalist attraction astatine the highest of the pandemic when it was unclear however overmuch illness was circulating.

The B.C. Centre for Disease Control (BCCDC) stepped up its surveillance and present regularly monitors the wastewater from astir the state to gauge microorganism levels — not conscionable for COVID-19, but besides for influenza and respiratory syncytial microorganism (RSV).

Scientists accidental they anticipation Canada continues to money that work. Ontario ended its COVID-19 wastewater surveillance program successful July 2024 and a probe vacuum is looming southbound of the border.

"Before the pandemic, determination was nary regular usage of wastewater data," said Natalie Prystajecky, an biology microbiologist astatine the BCCDC. "That was this immense innovation that occurred due to the fact that of the pandemic."

Prystajecky has worked connected the wastewater programme since the pandemic began successful 2020, and has been monitoring the different respiratory pathogens since 2022.

Humans who declaration COVID-19 volition shed traces of SARS-CoV-2 — the virus that causes the disease — in their feces, and authorities cod aggregate samples per week to amusement trends successful microorganism loads implicit time.

During the Omicron question of the pandemic successful precocious 2021, B.C.'s investigating capableness became overwhelmed — which is erstwhile the wastewater monitoring dashboard became 1 of the much reliable sources of accusation astir microorganism levels successful the community.

"That information became disposable publicly, and it seemed similar the nationalist truly ... was capable to recognize it and relied connected it," Prystajecky said.

The researcher said that the wastewater surveillance program, which expanded extracurricular Metro Vancouver during the pandemic, is present successful a spot wherever researchers tin amended woody with the adjacent pandemic.

How does it work?

Jesse Shapiro, an subordinate prof of microbiology and immunology astatine McGill University, was among galore researchers who analyzed wastewater samples shipped to labs astir the country.

There, helium says a "bunch of chemistry" is done to instrumentality wastewater from trial tubes and ore it into substances that tin past beryllium sequenced to find familial code.

The microbiologist said that, initially, trying to find the signals for a caller microorganism similar SARS-CoV-2 would person been similar uncovering a needle successful a haystack.

But arsenic scientists gained amended investigating methods, it became a batch much outgo effectual to observe however overmuch microorganism was circulating and what variants were much dominant.

"An vantage of wastewater surveillance is that it tin beryllium incredibly effective, due to the fact that those laboratory methods are really not precise costly astatine all," the prof said.

Future of wastewater surveillance

Shapiro was portion of the Coronavirus Variants Rapid Response Network (CoVaRR-Net), a cross-Canada web of researchers that was funded by the Canadian Institutes of Health Research and produced a fig of studies connected COVID-19 and different viruses.

However, the backing for the programme ended this month, and different wastewater surveillance programs person been removed successful provinces similar Ontario.

WATCH | Ontario ends wastewater investigating program: 

"We are seeing less programs similar this continuing to beryllium run," Prystajecky acknowledged.

"[In] these adjacent stages, we're starting to truly deliberation astir the champion and astir meaningful mode of utilizing wastewater surveillance."

Prystajecky said she is present utilizing the information to look astatine gut-based pathogens similar norovirus and salmonella, arsenic good arsenic antimicrobial absorption among pathogens.

Shapiro said he hopes that Canada is moving toward a aboriginal wherever there's much unfastened information sharing based connected wastewater surveillance, with academics connected manus to construe the information and marque nationalist wellness recommendations.

"It's incredibly important for things similar surveillance of vertebrate flu, H5N1, emerging pathogens, things that are spreading," helium said. "If you don't look, you won't find it."

As the U.S. government moves to chopped backing to the National Institute of Health and Center for Disease Control, which are some heavy progressive with wastewater surveillance, Shapiro said there's an accidental for Canada to capable the looming void and fund subject probe much broadly.

"I deliberation it's really rather indispensable for Canada and different countries to measurement up and not conscionable beryllium wholly reliant connected the U.S. for this benignant of thing," helium said.