How wastewater could revolutionize surveillance for pathogens like COVID, monkeypox and polio

This is an excerpt from Second Opinion, a weekly analysis of health and medical science news. If you haven't subscribed yet, you can do that by clicking here.

One night in March 2020, as wastewater researcher Robert Delatolla was making dinner at his Ottawa home, his wife wondered out loud: Was it possible to spot the novel coronavirus in the city's sewage system?

Delatolla had spent years of his environmental engineering career exploring wastewater treatment technologies — not tracking viruses. He scoffed at the idea.

"I obnoxiously said, 'It won't work,'" the University of Ottawa professor recalled.

A few days later, Delatolla realized his wife was right. In late March, Dutch researchers announced wastewater surveillance efforts in the Netherlands were successfully identifying the virus behind COVID-19, even before official cases were reported. 

Delatolla and his laboratory team raced to get a similar system up and running. "By April 8th, 2020, we were able to get our first detection," he said. "That was our first detection of SARS-CoV-2 in wastewater in Canada."

The first but not the last. 

For more than two years, research teams across the country — and around the world — have been using human waste to monitor rising and falling coronavirus levels. The approach can also be used to track the viruses behind monkeypox and polio. It's capable of spotting antimicrobial resistant bacteria or toxic drugs. And researchers say the public health possibilities are boundless. 

Still, the future of wastewater testing remains uncertain. 

Some Canadian scientists are concerned about insecure funding. Others believe scaling up surveillance on a global level is essential for tracking emerging pathogens — but that it's also fraught with challenges.

What's clear is this type of surveillance system works. And it starts with something we all just flush away.

On a hot August morning, you can smell the pungent brown sludge flowing through a concrete channel at a wastewater treatment facility in the east end of London, Ont. It's one of the dozens of Canadian sites participating in wastewater research projects in collaboration with various universities and public health agencies.

Roughly 20,000 cubic meters of wastewater — an amount that could fill eight Olympic-sized swimming pools — arrives at this facility each day. It's filled with all the random junk people flush down their toilets; human waste, of course, but also cereal, tampons, needles and masks.

"We get T-shirts, clothing, wet wipes," said Andrew Nimetz, a shift operator at the site.