The University of Virginia is now testing students once every nine days to try and prevent the spread of COVID-19 on campus, but the school is also using an early warning system – checking for signs of the virus in its sewers.
Rebecca Thompson is a soldier in the fight against COVID-19 – pouring ice into what looks like a large black cooler under a manhole cover. It’s one of more than a dozen robotic machines or auto-samplers taking material from sewers outside UVA dorms.
“I take samples every morning from all 16 machines,” she explains.
Those samples of wastewater are then checked for genetic material from the coronavirus – excreted by one or more students who may not know they have COVID.
“People start shedding RNA in their stool pretty early, and it’s usually before symptoms according to the literature.”
Dr. Amy Mathers is an expert on infectious disease.
“We can surveil an entire building as an early warning system, to see if COVID RNA shows up in the wastewater, and then go in and test individuals.”
Mathers and environmental engineer Lisa Colosi-Peterson masterminded this approach as a way to save money and spare students unnecessary testing.
“ It’s actually uncomfortable for people to be tested, and so we wanted to make sure we’re testing the right people in order to make a difference in fighting the pandemic, and so we use the wastewater to help us figure out who warrants more testing.”
“If you were to compare it to testing every person in the building, it pales in comparison on cost,” Mathers adds.
Mathers says this form of testing has its limitations. Some people who carry the virus will escape detection.
“If they have COVID, and they’re not using the bathroom in the facilities then we won’t catch it, which is one of the reasons that it’s kind of limited to where people live.”
And, she adds, testing so far involves relatively small buildings.
“We don’t know if we surveilled a one-thousand-person building if you would detect one person out of that using these methods.”
Sewer monitors are nothing new. They’ve been used to track down polio and other viruses around the world, but when UVA decided to try this approach, its associate director of energy and utilities, Paul Zmick, ran into a problem.
“As more folks want to do this, the auto-samplers are becoming harder to acquire,” he recalls. “We decided to build our own. Ours is much less expensive and readily available.”
They tested the system at dorms occupied by athletes in July, and by the time other students came back, Colosi-Peterson and Mathers had mastered the process that would detect cases of COVID at five different dorms. They also found it was possible to predict how many dorm residents would have COVID in a week, based on the amount of viral material detected.
As it happened, this breakthrough came from a team of women – all of them moms. Colosi-Peterson found that funny.
“I made that joke – that dealing with human waste freaks you out less if you are a parent.”
Of course that makes you wonder why Paul Zmick was happy to join the enterprise. Had he ever changed a diaper?
“Oh yes!” he says. “I have four kids.”
The UVA experience has drawn attention from other schools and nursing homes – hoping to set up a similar early warning system for COVID.
***Editor's Note: The University of Virginia is a financial supporter of Radio IQ.
