Since the end of March, Utah researchers have been testing wastewater in an attempt to track the spread of the coronavirus in the state. It’s an experimental program whose first phase ended Friday. Now the data will be turned over to the state’s Department of Health for analysis.
The hope is that the method can provide a community-wide picture of the virus, without having to individually test huge numbers of people. It might also offer a better sense of how many people have the virus but don’t show symptoms.
“That's the advantage of this kind of testing compared to testing each person in the state,” said Jennifer Weidhaas, a professor of engineering at the University of Utah and one of the lead researchers on the project. “We can look at, say, 10 or 15 treatment plants across the state and identify potential hotspots. It might also give us some peace of mind if we don't see the signals of the virus in different areas.”
The method has been used for tracking diseases for decades, Weidhaas said. But now, it’s being used around the world for the first time on a new infection.
In Utah, samples are being collected from 10 treatment plants throughout the state, then sent to researchers at the University of Utah, Brigham Young University and Utah State University. The samples are heated to kill the virus and tested for genetic traces.
Weidhaas said early data has so far revealed the virus spread in some unexpected places — though she could not say where. She said that’s likely a sign there are asymptomatic but infected people in those communities.
Jim VanDerslice, an environmental epidemiologist at the University of Utah, said while the method shows promise, it’s not clear yet how effective it is. Researchers don’t know, for example, how long the virus can live in the sewer system or how much of it ends up in human waste.
That’s why the study’s data is getting turned over to the state health department, which will look for a correlation between the number of positive cases it has confirmed and the concentration of the virus in the wastewater in a particular area.
“They know addresses for many of the people that have been tested,” VanDerslice said. “So they'll be able to take and assign each test result to the different wastewater service districts that we're working with.”
If the two seem to match up, he said, that will suggest the sampling is a helpful measure and could be used more extensively throughout the state, helping to guide public health orders going forward.
Jon Reed is a reporter for KUER. Follow him on Twitter @reedathonjon