CHICAGO (CBS) — The subject of this story may not be dinner table talk, but it could be a game-changer in the fight against COVID-19.

Chicago researchers are now testing sewage. As CBS 2’s Suzanne Le Mignot reported Tuesday evening, the goal is to zero in on communities where the virus is surging.

The researchers at the University of Illinois at Chicago haven’t found any clusters of COVID-19 cases in communities yet, but the goal is to be able to see what ZIP codes have the most cases – so as to give health officials advance warning of an outbreak.

For the past four weeks, researchers at the UIC School of Public Health lab have been analyzing wastewater from three Chicago area treatment plants located on the West, South, and North sides of the city.

The water samples are kept in one-liter bottles. Dr. Abhilasha Shrestha said they are looking for the novel coronavirus in the samples.

“By analyzing the sewer water, you can find out when an outbreak is going to arrive. You have like a week’s notice before an outbreak,” Shrestha said. “People who are infected with this virus, they start shedding the virus in their stool right away – even before they start showing symptoms.”

Shrestha said the research, funded by a $1.25 million dollar grant from the Skokie based Walder Foundation, is a game-changer.

“We can identify hot spots,” she said.

Shrestha said it is early warning for health officials to prepare for cases and to combat COVID-19 in communities.

“They can use this information to deploy resources, such as outreach intervention campaigns – like handwashing, wearing masks – to neighborhoods where we see and detect that the virus are increasing in their wastewater,” she said.

As recently as September, scientists and researchers in nearby Madison, Wisconsin were analyzing wastewater samples to get an idea of the level of coronavirus in communities.

Last month overseas, scientists were able to detect a surge in Covid-19 cases among asymptomatic people, in an English town.

This type of testing isn’t new. It has been used for decades to detect other viruses, like polio.

Researchers are also looking at other ways this testing can be used. They can provide insight as to whether an intervention such as mask-wearing and handwashing is effective.

Down the road, the sewage tests might also determine whether people in a community are taking advantage of vaccinations against the virus.

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