Looking at recent data posted on Clemson University’s Covid-19 dashboard, one might assume viral activity is low on upstate South Carolina college campuses.
The dashboard, which relies on positive Covid tests reported by local laboratories and campus medical offices, detected 34 positive cases among students in the third week of August and 20 in the previous week.
Those numbers pale in comparison to eight months ago, when the Omicron variant was first grown in the U.S. and Clemson averaged hundreds of positive Covid tests per day.
David Friedman, chair of the university’s Department of Environmental Engineering and Earth Sciences, who relies on such dashboards to assess the risk of Covid infection, said the latest data doesn’t paint the most accurate picture. With the proliferation of home Covid testing, only a small fraction of positive results are reported to public agencies. Many people with mild infections don’t get tested.
He said better data could be obtained on samples collected from sewage water, and those that showed viral activity this summer far exceeded the number of reported cases.
“In our area, the numbers are actually higher than ever [first] omicron surge,” said Friedman, who directs the department’s Covid wastewater surveillance program. “And yet case reports are often nil.”
While wastewater surveillance is proving to be the most accurate and economical way to measure Covid activity in communities across the country, Friedman and others say funding for this type of tracking is inconsistent. And data collection is sometimes halted while wastewater researchers look for new ways to pay for monitoring.
“To make wastewater data actionable, you have to monitor it,” says Mariana Matus, CEO and co-founder of Biobot Analytics, which has a $10 million contract with the federal Centers for Disease Control and Prevention to conduct wastewater surveillance. More than 300 sites across the US “The more you monitor, the easier it is to catch early changes and take action.”
Wastewater research is not new. The method was used in the 1940s to track polio outbreaks. Apart from Covid, the technique is being used to track the spread of monkeypox.
It collects a sample of wastewater, often at a treatment plant, concentrates it and processes it so that scientists can run an analysis — similar to PCR nasal swabs — capable of detecting the Covid virus, other infectious diseases and even genetic evidence of disease. Presence of opioids.
Historically, wastewater samples have been collected to measure community trends, such as the rise and fall of Covid cases. Recently, however, research published by Friedman and others in the Lancet Planetary Health journal showed that wastewater monitoring can be used to estimate the number of people infected in an area.
For most epidemics, Covid numbers reported on a daily or weekly basis by state and local health departments are combined with data collected by wastewater surveillance programs. Usually, when the cases reported by the health department increase, the amount of covid is detected in the waste water samples.
Data on Covid-related hospitalizations is also useful for measuring community spread and the severity of variants, but it is considered a lagging indicator, meaning the data reaches its peak weeks after Covid has already spread through a community, said Michael Sweatt, director. Medical University of South Carolina’s Center for Global Health, whose work focuses on Covid forecasting.
In contrast, because people shed Covid virus in feces before showing symptoms of illness, community-level infections may occur in wastewater sludge before the number of cases or hospitalizations.
Many scientists now consider wastewater monitoring a more precise way to track Covid activity in real time. Without wastewater monitoring, “we don’t have a very accurate reading of things,” Sweat said.
And researchers say, data collection is not expensive. Clemson’s program costs $700 a week, according to Friedman. Erin Lipp, who runs the Wastewater Monitoring Lab at the University of Georgia in Athens, said Covid testing costs about $900 a week.
According to a U.S. Government Accountability Office report released in April, countries could save millions or even billions of dollars using wastewater monitoring, but the potential cost savings are unclear. A general lack of cost-benefit analysis makes it difficult to determine how and when to use it, the report said.
Yet some labs say the lack of a consistent and centralized source of funding raises questions about how — or if — communities can continue this work.
“When we started this, it was basically any extra money I could find,” Lipp said. His lab has used CDC grant money to pay for surveillance for the past year, but the portion of funding dedicated to that test is set to expire at the end of August. The grant will sustain the lab through September.
“I’m very hopeful that we can find some way to continue this,” Lipp said. He worries that his lab, for the first time during the pandemic, is seeing a disconnect between the Covid spike in wastewater and the spike in clinical cases. “What we’re seeing is a huge undercount,” he said.
Wastewater monitoring sites often go “offline” for periods and then start working again, said Colin Naughton, assistant professor of civil and environmental engineering at the University of California-Mercedes. He created an online dashboard called CovidPoops19 that tracks wastewater surveillance efforts around the world.
Monitoring work can be intermittent, he explained, because funding comes from a variety of sources, including government, universities and the private sector.
At the Plum Island Wastewater Treatment Plant in Charleston, South Carolina, wastewater monitoring was suspended for more than two months this year. The project was reinstated this summer when the state Department of Health and Environmental Control took over control from the University of South Carolina.
“Of the academics I know who are doing this right now, we’re all facing similar funding problems,” said Clemson University’s Friedman.
For much of the epidemic, Clemson paid for its wastewater monitoring. The program faced a funding shortfall earlier this year, but Friedman said his lab has never been forced to suspend its surveillance. Before the money for his lab work ran out in May, Friedman turned to Biobot Analytics, which analyzes wastewater samples for about 50 independent projects in addition to work for the CDC.
BioBot’s wastewater monitoring network is funded by venture capital investments, Matus said.
Regardless of funding constraints, wastewater monitoring is moving forward. Nationally, more wastewater research is being conducted now than ever before.
Although some researchers have had to look for alternative sources of funding this year, CDC spokeswoman Jasmine Reed said that more than 1,000 CDC-funded surveillance sites are now operational across the U.S. The agency expects to begin collecting data on 200 more in the next few months.
This is good news for researchers who want more information. But many will face a whole other hurdle in combating the American public’s Covid burnout, Friedman said.
“People don’t want to hear about it anymore,” he said. “But if you look at the national statistics, we’re averaging about 400 deaths per day. We can pretend it’s not happening, but wastewater and death tell us a different story.”
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