Protecting a campus through its wastewater
At testing sites around the University of Florida, students, staff and faculty get swabbed to check for potential COVID-19 infections. Beneath their feet, another testing system churns away, searching for the virus in UF’s wastewater.
A team of public health, microbiology and environmental toxicology experts, partnering with medical and facilities personnel, created GatorWATCH, which stands for Wastewater Analysis and Tracking for Community Health. GatorWATCH monitors wastewater from 28 UF residence halls, campus apartment complexes and fraternity/sorority houses that empty into UF’s wastewater treatment infrastructure, alerting the UF Health Screen, Test & Protect initiative when the virus is detected.
So far, the residences where the virus has been detected in wastewater have already been identified by above-ground testing. The virus was not found in dorms where cases had not been previously identified through standard nasal swab testing. The results validate the accuracy of the wastewater surveillance, which means that as cases decrease, GatorWATCH can provide clues to where the virus might linger — and where other public health threats could pop up.
Wastewater testing is a proven strategy used in the control of other infectious diseases that helps detect unsuspected infections,” said Dr. Mike Lauzardo, director of UF Health Screen, Test & Protect. “If we find evidence of infection, we will then direct our testing efforts at that site and quickly diagnose the unsuspected case. We are using every resource at our disposal to get as much information about infections on campus during the pandemic, and wastewater testing will be an important weapon in the fight against COVID-19.”
While the wastewater surveillance effort was created with COVID-19 in mind, the faculty leading these efforts, Drs. Joe Bisesi, Tony Maurelli and Tara Sabo-Attwood — professors with UF’s Department of Environmental and Global Health in the College of Public Health and Health Professions and Emerging Pathogens Institute faculty — see potential beyond the current crisis.
From pathogenic E. coli to campylobacter and salmonella, "there are numerous other infectious diseases that could be monitored through this methodology,” said Bisesi, Ph.D., an environmental toxicologist. “There is potential to use this type of monitoring to track effectiveness of vaccine campaigns if one became available and a suitable marker could be found, as has been done with polio vaccine.”
Community health researchers could even use wastewater testing to understand patterns of pharmaceutical and illegal drug use.
Because ours is a multidisciplinary, intercollege approach, we see things across the spectrum, not just COVID,” said Maurelli, Ph.D., a molecular biologist. “We’re just at the very start of unleashing the potential of wastewater surveillance in public health.”
The team began planning GatorWATCH in April and drew its first sample on the UF campus in early September.
“We went from 0 to 60 in an extremely short period of time with very limited resources,” said Sabo-Attwood, Ph.D., an aquatic and pulmonary toxicologist.
She attributes their success partly to the diversity of experts at UF, including leading coronavirus virologist Dr. John Lednicky, Ph.D., as well as the team’s experience creating UF’s rapid COVID-19 testing lab in just 10 days.
“Joe and Tony and I spent a lot of time together getting the testing lab up and running. That helped us strengthen our working relationship,” she said.
The team’s first challenge was unraveling the wastewater infrastructure of a 2,000-acre campus, working with UF Facilities Services to devise a system where each sampling location would cover a total of about 500 residents in the building or building group captured in each sewage sample. Then they needed to build the sampling hardware, which was complicated by supply chain challenges.
Combining parts from Amazon and other retailers, custom fabricated pieces and commercially available samplers, Bisesi created a self-contained sampling system that fits beneath a manhole cover. A sampling device fills a bottle with a small amount of wastewater at set intervals to create a composite sample for each site that gets labeled and inventoried.
Samples are then tested by members of the team for the genomic signature of the virus using quantitative reverse transcription PCR technology similar to nasal and saliva tests. The testing shows how much virus is coming from a particular residence hall, but the scientists don’t yet have enough data to correlate that to an estimated number of cases.
The UF team is also conducting wastewater sampling for the city of Gainesville and the Gulf Coast town of Cedar Key.
“This really shows the impact of environmental science in context of public health,” Sabo-Attwood said. “I’m proud to use our expertise to rapidly and effectively improve the public health of our community.”