Coronavirus-infected sewage found in Columbia plant. Does it signal another flare-up?
Scientists have discovered coronavirus in sewage at Columbia’s wastewater treatment plant as part of an investigation into how much more extensive the virus might be in South Carolina — and whether the disease could flare up again later this year.
Last week’s finding by a team of researchers is significant because it marks the first known occurrence of coronavirus in sewage flowing into a South Carolina treatment plant since COVID-19 began to infect and kill people across the state more than a month ago.
Coronavirus in sewage is not believed to threaten the Congaree River next to the plant. But the findings provide a valuable first step in efforts to predict when the disease might recur, according to researchers at the University of South Carolina.
If scientists can establish how much coronavirus is showing up in sewage now, they can compare it to sewage samples they take at other times this year to determine when levels are rising or falling.
A spike in coronavirus levels in sewage could let communities across South Carolina know that another round of COVID-19 related illness is on the way, said Sean Norman, USC’s lead researcher. At this point, researchers don’t have a clear picture of the level of coronavirus in Columbia’s sewage, but USC’s research is intended to show that.
“If we can get a baseline, it might allow us to develop an early warning system if we get a second wave of the virus occurring,’’ he said, noting that ‘’learning from the science on how to prevent future infections would be the gold star.’’
Some forecasters have said the disease will die down during the summer, but could come back later in the year as the weather cools. The U.S. Centers for Disease Control and Prevention’s top official said Tuesday that a coronavirus disease outbreak next winter could be worse than what the U.S. is experiencing now.
USC researchers plan to test sewage flowing into the Columbia plant weekly for a year to determine how much coronavirus is in waste piped to the treatment plant from homes and businesses, Norman said.
Coronavirus germs from infected people can pass through their bodies and be flushed into the sewer system as waste, according to the S.C. Department of Health and Environmental Control.
Congaree Riverkeeper Bill Stangler said Norman’s work is important to learn how the virus might be affecting the community, beyond what already is known.
“This is interesting research that is going on that hopefully can shed some light on the prevalence of this virus in our community and the steps we can take to deal with it,’’ he said.
Stangler, state health officials and Clint Shealy, Columbia’s assistant city manager over water utilities, said they doubt the virus will get into the Congaree River from the treatment plant because the treatment process should kill the germs in any water that is discharged.
While people could be exposed to coronavirus-infected sewage if there were a spill from a pipe before wastewater reached the plant, Norman said the virus would not likely survive for long if it leaked from a pipe.
Norman’s research is part of a growing number of scientific studies of whether coronavirus germs are living in wastewater, and whether sewage can be used to predict future outbreaks of the virus.
Researchers in the Netherlands, Australia, New Zealand, Sweden and parts of the United States have found traces of coronavirus in raw sewage, according to Norman and a recent report in Nature, a scientific journal.
The Nature report said researchers want to know if they can determine the level of coronavirus in waste material, so they can come up with a number of infected people in an area.
Scientists In Massachusetts already have made such a finding. MIT researchers say there are as many as 100,000 more cases of coronavirus in just one section of the state than had been identified by early April, according to a report in the Boston Herald.
USC researchers hope to make similar determinations, in addition to predicting if and when the disease might come back. The U.S. Centers for Disease Control and Prevention and the Department of Health and Environmental Control are providing funding for Norman’s work at Carolina.
“We are all trying to accomplish the same thing,’’ said Norman, an associate professor in USC’s Arnold School of Public Health. He directs the school’s molecular microbial ecology laboratory.
USC’s efforts should be of particular interest in the Columbia area, where the coronavirus has broken out with a fury, killing at least 14 people.
Richland County, one of the state’s largest counties with more than 400,000 residents, had the highest number of coronavirus cases in the state at nearly 700 early this week. The county also has one of the highest per capita infection rates and the highest number of people who have died from the virus in South Carolina.
The sewage flow studies also could give a broader view of the problem in communities outside Columbia that have reported fewer cases of the coronavirus.
In addition to Columbia, where the virus has been well documented, sewage sent to five other treatment plants also will be tested across South Carolina, including along the coast and the Upstate. Norman declined to name those plants because the studies are just starting, but said some are smaller plants.
If the number of confirmed coronavirus cases reported to the state are low in some areas, but the levels in sewage are high, it would indicate not enough testing has been done. That’s a key concern in some rural communities where relatively few coronavirus cases have been identified.
‘‘We could get a better idea of what is truly cycling in some of these areas that may not be tested quite as much,’’ Norman said.
The CDC will help calculate the abundance of the virus in South Carolina communities after samples are run in laboratories, Norman said. The S.C. Department of Health and Environmental Control is participating in the research, as well, he said.
This story was originally published April 21, 2020 at 6:42 PM.
