By Riley Morningstar
CLEMSON — The latest wastewater monitoring results in Clemson show the highest detection of SARS-CoV-2 — which causes COVID-19 — on Clemson University’s campus since early last month, a stark contrast to the drop-off in recently confirmed cases.
In data published earlier this week, officials noted an uptick from “below detection levels” to levels of concern for the potential of active transmission of COVID-19.
In samples collected July 28, there were 14,000 virus copies per liter detected, the most since the July 2 sampling at the university’s wastewater treatment plant.
“This tells us there are still infected individuals working on campus,” a release from the city said.
Dr. David Freedman, the chair of Clemson University’s department of environmental engineering and earth sciences, has been leading the wastewater research since late May. Freedman was hesitant to put too much stock into the latest numbers from the university’s system.
“Those numbers are still very, very low,” he said. “It means there are only a couple of infected individuals that utilize the facilities on campus. I think it’s something worth keeping an eye on, especially as the number of people returning to campus starts to increase. It’s still at a very low level.”
University officials announced initial results from employees’ COVID-19 tests taken over a five-day period in late July. There was a 2 percent positivity rate out of more than 1,900 tests taken by employees, well below the 14-day average positive rate of approximately 15.2 percent reported by the S.C. Department of Health and Environmental Control (DHEC) the day results were released.
The World Health Organization suggested government officials should aim for a 5 percent or lower positivity rate for at least 14 days ahead of reopening.
“The population that has been tested by the university is showing a pretty low frequency, and that’s consistent with the people using the campus being pretty careful — but that’s a very selective population in the area,” Freedman said. “I think (they’re) people who are more attuned to following social distancing, wearing masks and following social distancing than the general population.”
Virus copies continue to fluctuate at the Cochran Road Wastewater Treatment Plant, which services many off-campus apartments.
In one week, from July 21-28, virus copies increased from 59,000 to 910,000, raising the concern level to “significant.” DHEC reported a total 271 confirmed cases of COVID-19 in Clemson’s 29631 ZIP code on Friday, with 1,665 probable cases estimated.
Freedman called the July increase “an outlier.”
“It happens. That’s the nature of the beast,” he said. “Until we see a consistent trend at both treatment plants to levels that are in that range, we know there’s still a significant number of infected individuals in the area.”
Freedman said researchers are still waiting to see if any trends emerge after Clemson implemented a mandatory mask ordinance that was passed on June 24.
“So far, we have not seen a consistent response,” Freedman said.
Whether a trend emerges or not, Freedman said he has doubts as to whether spotty mask wearing will help the community.
“I think it would be a good question for epidemiologists as to whether or not the practices that we’re following now are adequate to flattening the curve as needed,” he said. “The wastewater doesn’t lie. It does not lie.”