In an effort to detect student cases of the novel coronavirus, U.Va. Health is analyzing wastewater samples from University dorms for the presence of SARS-Cov-2, the virus that causes COVID-19. After positive indicators of the virus were discovered in the wastewater of the first-year residence hall Balz-Dobie and five residents tested positive for the virus, the University announced Wednesday that the dormitory's 188 residents would be tested for COVID-19 to stymie a potential outbreak. This is the first time the University’s wastewater testing program has contributed to dorm-wide testing.
The goal of the wastewater program is to detect early and asymptomatic coronavirus cases. Research has shown that the genetic material of SARS-CoV-2 is shed in the stool of infected individuals and can be detected prior to the appearance of clinical symptoms. According to health officials, this information can help prevent COVID-19 outbreaks. This method is being used to complement other testing methods on Grounds, including randomized testing of students for the virus.
For residence halls across Grounds, wastewater samples are being collected every 15 minutes and pooled over a 24-hour period. U.Va. Health then tests the pooled samples to determine if anyone living within a given residence hall may have contracted COVID-19. If the virus is detected in a pooled sample from a residence hall, all residents from that dorm will be tested individually for the virus.
Amy Mathers, infectious disease physician and associate director of clinical microbiology, was instrumental in developing novel coronavirus tests in March and is now using her expertise to carry out wastewater testing on Grounds.
Mathers became interested in pooled wastewater testing after being struck by the amount of resources needed to keep up with demand for individual coronavirus tests.
“When you’re talking about thousands and thousands of tests for surveillance purposes, the manpower it takes to collect specimens is enormous,” Mathers said. “There were some murmurings [from other universities and scientific literature] that you could detect the COVID RNA signatures in wastewater … I know how to detect COVID signatures in clinical samples, [and said] ‘let’s see if it works for wastewater.’”
Mathers worked directly with Lisa Colosi-Peterson, associate professor in engineering systems and environment, to bring wastewater testing to fruition on Grounds. Mathers and Colosi-Peterson had already been collaborating prior to the pandemic to test hospital wastewater for antibiotic-resistant pathogens.
Colosi-Peterson explained that she became interested in the potential of wastewater testing as a tool to predict COVID-19 outbreaks.
“As an engineer, we love when we can get predictive information because that gives us time to intervene and mitigate what could happen,” Colosi-Peterson said. “Especially in the context of an outbreak, you want to get in as early as you can to do some intervention.”
Colosi-Peterson was also curious from an engineering perspective about variables which might impact wastewater testing from a building, such as additional sources of water from laundering, which could dilute the wastewater, and cleaning detergents and bleach, which could mix with the wastewater and degrade the virus.
“Actually, from our pilots over the summer, we don’t think those things really have strong impacts on our ability to get results,” Colosi-Peterson said. “The method is really sensitive.”
This summer, Mathers, Colosi-Peterson and their teams worked on pilot studies testing wastewater from the University hospital to ensure they could detect SARS-CoV-2. Now that students have returned to Grounds, the team has focused their efforts on dorms.
Mathers explained that dorms are a top priority since they could be hotspots for COVID-19 transmission.
“Places people live together are at especially high risk for transmission, and it’s because you can’t wear a mask every hour of the day and you’re indoors,” Mathers said. “So we see COVID transmission occur quite quickly in buildings where people live together.”
Mathers and Colosi-Peterson have worked closely with University Facilities Management to ensure widespread sample collection on Grounds. On any given day, up to 10 small robots, called auto-samplers, are stationed at manholes near dorms for sample collection.
Paul Zmick, senior associate director of energy and utilities, explained that his group uses detailed maps of Grounds to choose wastewater testing locations. Locations are chosen to test as many students as possible while avoiding testing locations where outside sources can contribute to the waste stream, like public restrooms. The number and exact placement of these testing locations varies on a day-to-day basis to ensure that every dorm’s wastewater is monitored every few days.
Once samples are collected, Facilities Management personnel deliver chilled wastewater samples to Mathers and her team, who then test the samples within 10 hours.
Zmick highlighted that his team has enjoyed working with other University disciplines to contribute to research and the overall mission of the University.
“This is truly a combined U.Va. effort,” Zmick said. “We have the Health System side, the academic and teaching and research side, we have Facilities, and not only utilities but the part of facilities that helps manage housing … [Facilities is] out there working in the roads, working in sanitary systems all day every day, so we are in a unique position to help.”
Like with any testing method, there are some limitations to wastewater testing for SARS-CoV-2. A major concern is the possibility of a false positive. Research suggests that just as SARS-CoV-2 is shed in the stool very early during infection, it can also continue to shed past resolution of symptoms, at times when a person no longer poses a risk to others.
Mathers, Colosi-Peterson and their teams are working to mitigate this issue by focusing on
high signals of coronavirus genetic material in their tests, which are strongly correlated with earlier infections. Without receiving the identity of any students, the wastewater testing team can also check with Student Health to see if a student who has recovered from the virus has recently returned to a dorm from quarantine if a dorm returns a weakly-positive signal.
Another challenge is that while most dorms, such as dorms on McCormick Road and Alderman Road, can be sampled efficiently, rooms on the Lawn and Range cannot be sampled without risk of outside contamination from other wastewater sources. The same obstacle is preventing testing of wastewater from student residences off Grounds.
Nevertheless, wastewater testing can be used to supplement all other testing at the University and can monitor a large portion of the student population with the hope of preventing COVID-19 outbreaks.
Wastewater testing officially began when students began moving in the first week of September, but the program’s first fully operational week began Sept. 7.
The mandated testing of Balz-Dobie residents Wednesday evening is the first time the University has administered COVID-19 tests to an entire dorm this semester over fears of a potential outbreak. Students in the dorm have been asked to quarantine and wear a mask at all times, including in their rooms, unless they are going to sleep. Should a student test positive, they will be moved to one of the University’s isolation rooms, and any close contacts will be relocated to a quarantine room.