COVID-19 testing clinics across the country are closing and federal funding for free clinical testing is drying up. But sewage monitoring could step in to play a crucial role in keeping track of where the virus is and how much is actually circulating there, according to two San Antonio professors who work on water monitoring worn COVID since the start of the pandemic.
dr. Vikram Kapoor is a lecturer at School of Civil and Environmental Engineering and Construction Management to UTSA. He is the main author of a study of COVID-19 in Bexar County wastewater who have found that this type of surveillance is an effective tool for determining trends in infectious disease prevalence and providing complementary information to clinical testing.
Kapoor also concluded that you could use sewage monitoring to try to get ahead of COVID.
“We call it a surveillance leading indicator because it can predict before the infection starts to spread. Before people start having symptoms, before they get tested, they will start shedding the virus in the stool,” Kapoor said. “So if everyone infected sheds the virus, there’s a chance we could pick up that signal days or even a week before they’re actually tested.”
Scientists tracking COVID in New York’s sewage found the same thing. Dr. Davida Smyth is now Associate Professor of Microbiology at Texas A&M San Antoniobut she was working in New York when the pandemic started.
They would check the sewage for COVID, then sequence what they found to see what variants were there.
“I think the first evidence we had that it was really predictive was when Omicron showed up,” Smyth said. “We were actually able to show that it happened before (it appeared in) people. So this proved that it actually works. “
Smyth thinks communities around the world could use the technique to get ahead of new variants and potential surges, and to fight the virus more effectively.
“The sewage data gives you maybe two weeks of lead time and what’s actually going to show up in the human population,” she said. “So you can say to yourself, ‘Well, a new variant is coming,’ and you can actually look and see where it is in the city and say, Well, that’s where it’s emerging.”
Then, Smyth said, you could target mask-wearing and other interventions on that specific area, which would be more effective and efficient than locking down entire cities.
Smyth and Kapoor plan to work together to set up a surveillance and sequencing program in South Texas, but so far things are moving slowly. They struggle to access new samples to test, and funding is always scarce.
The Centers for Disease Control have implemented a dashboard where states can report the results of their wastewater monitoring, but currently only about a dozen states are submitting information. Texas is one of them, but only a handful of Houston-area factories are currently participating.
Related: Sewage testing could help control the spread of COVID. Why isn’t this happening across America?