Coronavirus in wastewater treatment plants potential pathway to population testing

Environmental health scientist partners with CDC and SC DHEC to detect virus in 11 locations

Though the United States is far from being able to quickly test its entire population for COVID-19, scientists in the university’s Arnold School of Public Health and in a handful of labs around the world might have a faster and better alternative.

Environmental health sciences professor Sean Norman is tracking the presence of COVID-19 virus particles in wastewater treatment plants at eight locations in South Carolina, two in Texas and one near San Francisco. Data from his research will soon feed into a computer model developed by the Centers for Disease Control to calculate how many people in a given community have the virus. Once validated, the model could prove useful in predicting future waves of the virus.

“This is a field that scientists are starting to call wastewater epidemiology,” Norman says. “This methodology has been used for tracking the community presence of several other viruses in recent years, including polio.”

Norman already had been funded by the CDC to conduct research on the presence of antibiotic-resistant bacteria in wastewater treatment facilities. When the COVID-19 pandemic hit, Norman shifted his focus to search for the virus in wastewater.

“One might think of this as looking for a needle in a haystack, but it’s really not because we’re using very specific types of tools to identify this virus out of everything else that’s coming in through the raw sewage,” Norman says.

Data on the quantity of COVID-19 particles per liter of wastewater must be coupled with other information — the number of individuals served by a particular treatment plant and average volume of viral particles shed by infected individuals, for example — to calculate how many people in a given community have the virus, Norman says.

While testing of the CDC model will soon begin, Norman says it could take up to six months to fully tweak the model and confirm its accuracy.

“If we can get to the true abundance of the virus in the population, we might be able to turn this into a predictive model,” he says, “Then, by monitoring the abundance of the virus in the raw sewage, it’s possible that an uptick in the presence of the virus in sewage would signal the approach of another wave of COVID-19.

“Public health authorities and other decision-makers could then ramp up social distancing requirements again before the number of cases became a burden on our health care system.”       

In addition to wastewater sample collection and analysis, Norman is conducting broader research at one of the Columbia wastewater treatment facilities that involves monitoring the health of plant staff members. He is also keeping close watch on air quality near the plant to determine if virus particles might become aerosolized.

Field research and laboratory testing of wastewater carries some level of risk, “because there’s a lot of potential pathogens in sewage that can harm you,” Norman says. That’s why he and his research team use N95 respirators and other protective clothing to protect themselves from bacterial and viral pathogens that might be present in the wastewater.

“We run a biosafety Level 2 laboratory, so we take a lot of precautions already,” he says. Eventually, Norman plans to work with researchers at a Level 3 lab to determine if the COVID-19 viral particles he is detecting in wastewater are actually infective or merely benign molecular fingerprints of the virus.

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