Towns testing sewage to track coronavirus spread
CONNECTICUT - The alert went out late last week: the Mayor of Stamford, Connecticut warning of a possible surge in COVID-19 cases.
"We were seeing an increase of coronavirus residue in our wastewater," Mayor David Martin said. "When I say rising, it was five times what it was a few weeks earlier."
Stamford is one of a number of municipalities in our area where scientists are monitoring wastewater for evidence of the coronavirus. Since early on in the pandemic, researchers have found fragments of the virus' RNA in wastewater, often days before the person carrying it becomes symptomatic.
"I like to think of the wastewater surveillance as a smoke detector in the community, and you can pick up the traces of smoke before the house is on fire, so to speak," said Dr. David Larsen, an Associate Professor of Public Health Syracuse University which has teamed up with some SUNY campuses, Quadrant Biosciences and the State of New York to track Covid-19 in wastewater.
"We know about half of people infected with COVID will shed RNA in their feces and everybody poops, so if you're able to take a sample of wastewater from treatment plant you can obtain this representative sample of the entire community," he explained.
Larsen says sampling a community's wastewater is far more efficient, and cost-effective, than doing mass testing.
"Comparatively it would be like testing 500 people a day every day," he said of the surveillance efforts.
In Stamford, which is working with researchers from Yale University, Mayor Martin believes the early indicator last week may have helped stave off an outbreak.
"Fortunately, whether it's just good luck or whether it's because we actually got control of something, the amount of Coronavirus residue in the wastewater has dropped back down," he said.
Right now wastewater surveillance is being done by various institutions in cities and states across the country but in a very piecemeal fashion. Scientists like Larsen think having a coordinated national testing system could be key to avoiding resurgences of the virus.