Researchers at the University of Wisconsin-Milwaukee School of Freshwater Sciences are studying sewage as a means of tracking COVID-19 infections.
Sandra McLellan, a professor at the School of Freshwater Sciences, said her team is gathering samples from sewerage districts in high population areas, such as Milwaukee, Racine and Green Bay.
The research could spot an uptick in COVID-19 in these areas sooner than currently possible, and be used to alert communities of pending outbreaks days or weeks sooner than current models.
Ryan Newton, assistant professor with the School of Freshwater Sciences, who is also involved in the research, said samples are being taken from the water flowing in from treatment plants. They are also receiving sludge samples from the Metropolitan Milwaukee Sewerage District, he said.
Studying the samples can reveal information not being picked up by live testing, especially when considering the number of people who are asymptomatic and not getting tested, McLellan said.
“That’s where I think the sewage surveillance … really fills that gap on early warning, where with all these asymptomatic people, really the only indication we have is a downstream response with these hospitalizations and deaths,” she said.
There’s more work to be done before the team can definitively say what the sewage sample trends say about a coronavirus outbreak, but researchers say the findings could be significant.
“What we hope is we could provide additional information to all the other information people are gathering,” Newton said. “Even if it gives us a couple days’ warning, that’s still better than they would have had.”
The Wisconsin State Laboratory of Hygiene could also get involved in the research to monitor the rest of the state.
McLellan also noted the potential economic impacts. The research would help determine whether reopening businesses causes another spike in cases, she said.
“That has a huge impact on our economy, that we can have some confidence that reopening is going OK,” she said. “And of course, you could get an indication that reopening is not going OK, but having an early indication of that so we can put the breaks on and don’t have to go into total shutdown, I think the surveillance has great health implications but definitely is tied to the economic health of the state, too.”