Looking at recent data posted to Clemson University’s COVID-19 dashboard, one would assume that virus activity is low on the university campus in northern South Carolina.
The dashboard, which relies on positive COVID tests reported by local labs and on-campus doctors’ offices, identified 34 positive cases among students in the third week of August and 20 cases the previous week. .
Those numbers pale in comparison to those of eight months ago, when the omicron variant first hit the US and Clemson averaged hundreds of positive COVID tests each day.
For those who rely on these kinds of dashboards to assess risk of contracting COVID, recent data doesn’t paint the most accurate picture, said David Freedman, who chairs the department of environmental engineering and of earth sciences from the university. With the proliferation of home COVID tests, only a small fraction of positive results are reported to public agencies. Many people with mild infections do not get tested.
He said better data can be found in samples taken from sewage and that these showed virus activity this summer is much higher than the number of reported cases suggests.
“In our region, the numbers are actually higher than at any time, except for the [first] omicron surge,” said Freedman, who leads the department’s COVID wastewater surveillance program. “And yet the case reports often suck.”
Even though sewage monitoring is proving to be the most accurate and cost-effective way to assess COVID activity in communities across the country, Freedman and others say funding for this type of monitoring is n was not consistent. And data collection is sometimes interrupted as wastewater researchers look for new ways to pay for monitoring.
“For wastewater data to be actionable, you have to observe it,” said 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 provide wastewater monitoring at over 300 sites across the United States “The more you observe, the easier it is to detect early changes and take action.”
Wastewater research is not new. The method was used in the 1940s to track polio epidemics. Besides COVID, the technique is being used to track the spread of monkeypox.
It involves collecting a sample of sewage, often from a sewage treatment plant, concentrating it and treating it so that scientists can perform an analysis – similar to a PCR nasal swab – that can detect genetic evidence. of the COVID virus, other infectious diseases, and even the presence of opioids.
Historically, sewage samples have been taken to assess community trends, such as the rise and fall of COVID cases. More recently, however, research published by Freedman and others in the Lancet Planetary Health journal found that sewage monitoring can be used to estimate the number of infected people in an area.
For much of the pandemic, COVID numbers reported daily or weekly by state and local health departments evolved in parallel with data collected by wastewater monitoring programs. Typically, when cases reported by health departments increased, the amount of COVID detected in sewage samples also increased.
COVID-related hospitalization data is also useful for measuring community spread and assessing the severity of variants, but is considered a lagging indicator, meaning the data tends to peak weeks after COVID is already plaguing a community, said Michael Sweat, director of the Center for Global Health at the Medical University of South Carolina, whose work focuses on COVID predictions.
In contrast, because people shed the COVID virus in feces before they show symptoms of illness, community-level infections may appear in sewage sludge before case numbers or hospitalizations begin to rise.
Many scientists now see sewage monitoring as a more accurate way to track COVID activity in real time. Without wastewater monitoring, “we just don’t have a very accurate reading of things,” Sweat said.
And the researchers say collecting the data isn’t expensive. According to Freedman, the program at Clemson costs $700 per week. Erin Lipp, who directs the sewage monitoring lab at the University of Georgia in Athens, said COVID tests cost around $900 a week.
According to a US Government Accountability Office report released in April, countries could save millions or billions of dollars by using wastewater monitoring, but the potential savings remain unclear. A general lack of cost-benefit analyzes makes it difficult to determine how and when to use it, according to the report.
Still, some labs say the lack of a cohesive, centralized funding source raises questions about how — or if — communities can continue to do this work.
“When we started this, it was basically extra money that I could find,” Lipp said. His lab has used CDC grant money over the past year to pay for surveillance, but the portion of the funding dedicated to those tests is set to expire at the end of August. Donations will support the lab through September.
“I’m hopeful that we can find a way to continue,” Lipp said. She worries that her lab, for the first time during the pandemic, is seeing a disconnect between spikes in COVID in sewage and spikes in clinical cases. “What we’re seeing is a huge undercount,” she said.
Wastewater monitoring sites are often “offline” for periods of time and then resume work later, said Colleen Naughton, assistant professor of civil and environmental engineering at the University of California-Merced. She has developed an online dashboard called CovidPoops19 that tracks wastewater monitoring efforts around the world.
Monitoring work can be intermittent, she explained, because funding comes from such a variety of sources, including governments, universities and the private sector.
At the Plum Island sewage treatment plant in Charleston, South Carolina, sewage 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 control of the University of South Carolina.
“Academics I know who have done this so far, we all face similar levels of funding challenges,” said Freedman, of Clemson University.
For much of the pandemic, Clemson paid for its sewage monitoring. The program faced a funding shortfall earlier this year, but Freedman said his lab was never forced to suspend monitoring. Before the money for his lab work ran out in May, Freedman turned to Biobot Analytics, which, in addition to the work he does for the CDC, analyzes wastewater samples for about 50 projects. independent.
Biobot’s wastewater monitoring network is funded by venture capital investment, Matus said.
Regardless of funding barriers, wastewater monitoring is progressing. Nationally, more wastewater research is being conducted than ever before.
Although some researchers had to seek other sources of funding this year, CDC spokeswoman Jasmine Reed said more than 1,000 CDC-funded monitoring sites are now operational in the United States. The agency expects another 200 to start collecting data in the coming months.
This is good news for researchers who want more data. But many will face a whole other hurdle in the fight against COVID burnout of the American public, Freedman said.
“People don’t want to hear about it anymore,” he said. “But if you look at the national statistics, we are averaging around 400 deaths a day. We can pretend it’s not happening, but sewage and deaths tell a different story.
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