SALT LAKE CITY — People lacking any symptoms of COVID-19 are not rushing to get the painful nasal swab test, but they do go to the bathroom.
What they are flushing down the toilet may ultimately help the state of Utah get a better, more localized picture of infection rates — at least that is the hope of researchers behind a pilot project launched in March to test samples of untreated wastewater for the presence of COVID-19 gene copies.
The virus in its flushed form is no longer alive, but copies of its genetic material get left behind.
“What we are doing is measuring the number of viral genomes that we see in wastewater,” said Brigham Young University professor Zach Aanderud, one of a trio of researchers involved in the project.
“A lot of places around the country and the world are looking at wastewater for COVID rates,” he said.
The research team worked with 10 wastewater districts and specifically concentrated on what Aanderud described as “sewer sheds” that serve particular communities.
In contrast to a county health department, which reports infection rates, hospitalizations and deaths at the countywide level, a sewer district may only serve a handful of communities in that county.
The more localized data analyzed from the specific wastewater treatment plants may provide a more detailed picture of infection rates without sampling thousands of people, and offer additional information about the levels of asymptomatic infection.
“What we are trying to do is determine how those gene copies found in water relate to infection rates,” Aanderud said. “Everything passes through your body in wastewater.”
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Sampling sewage to get a community health snapshot is not new.
An article in the Scientific American detailed a more than 15-year effort by Arizona State University to sample sewage in collaboration with partners in China and Australia involving 300 cities.
Isolating the sewage for rates of opioid addiction, for example, looked to be a promising tool to attack that particular health crisis.
Rolf Haden, ASU’s lead researcher in the effort, told the magazine that sewage is the “information superhighway under your feet.”
The 24-hour composite samples taken from Utah wastewater treatment plants have been turned over to the Utah Department of Health, with results expected to be released next week. There will be an interactive website so residents can check out localized results from the various plants.
Jennifer Weidhass, project lead and associate professor of civil and environmental engineering at the University of Utah, developed the method for quantifying the concentration of COVID-19 in wastewater, and is hopeful it may prove to be a useful tool to develop localized responses to outbreaks in specific communities.
“This may be a better community-based surveillance tool,” she said. “(The health department) will be able to tell us how well our numbers correlate with public health data and if there are areas of concern or not and where they want to go in and provide more public health interventions in those communities.”