A study at USC is relying on the flush of a toilet for clues to coronavirus outbreaks.
Dr. Adam Smith, associate professor of civil and environmental engineering at USC, is a part of a team of scientists across the country who are sifting through data from the bowels of the sewer system. The team consists of researchers from USC, Howard University, North Carolina State University and Rice University.
Scientists received $200,000 from the NSF RAPID fund to conduct their waste water surveillance study.
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Dr. Smith said that although COVID-19 is a respiratory virus, it is still in individuals' gastrointestinal tracts, and is shed in human waste.
Although many individuals are asymptomatic, they could still be shedding or spreading the virus, and researchers are able to detect this in a noninvasive way through waste.
Dr. Mas Dojiri, chief scientist for LA Sanitation, has his team assisting in two different nationwide research projects, including the study at USC.
“Wastewater based epidemiology is not really new. It has been used to detect polio virus, hepatitis virus,” Dr. Dojiri said.
LA Sanitation is collecting waste water samples at five locations where sewage enters the Hyperion Water Reclamation Plant in Playa Del Rey.
Dr. Smith and his team then extract the genetic material of the coronavirus.
The plant treats the wastewater of about 4 million people throughout LA County. As a result, the information collected will expose trends spanning 600 square miles.
Dr. Smith said USC is exploring the option of testing the waste water of residence halls when students return to campus. The university is currently collecting samples from a dorm on campus where student athletes are living this summer.
The researchers are also looking into the waste water downstream of two hospitals treating COVID-19 patients in Santa Monica, UCLA Medical Center and St. John’s.
How Coronavirus Has Grown in Each State — in 1 Chart
This chart shows the cumulative number of cases per state by number of days since the 50th case.
Source: The COVID Tracking Project
Credit: Amy O’Kruk/NBC
“That will be a really nice, accurate way to compare the number of cases to the quantity that we’re detecting in the waste water,” Dr. Smith said.
Scientists think sewers could be a powerful early warning system to detect outbreaks across the country.
“Sewage testing could give us close to 10 days before a resurgence in infection,” Dr. Dojiri said.
The researchers hope to ultimately collaborate with local public health departments, to help prepare communities for potential coronavirus outbreaks.