As the pandemic continues, some cities, including Columbus, are turning to an unconventional source for COVID-19 information: the sewer.
For the past three months, Columbus City Utilities has been having wastewater tested by Pace Analytical in an effort to uncover data that could help predict new positive cases.
“The hope is that this will lead in projecting the number of cases in the community, because people may be shedding the virus prior to them having symptoms,” said utilities executive director Scott Dompke at a recent board meeting. He said that Columbus City Utilities has been working with the local health department on this endeavor.
According to a report prepared by Angie Bowling, who works in Columbus City Utilities’ Quality Control Lab, “Wastewater can be tested for RNA (ribonucleic acid). This is the nucleic acid that is used in key metabolic processes for all steps of protein synthesis in all living cells and carries the genetic information of many viruses. … Researchers have found that both symptomatic and asymptomatic COVID-19 infected people shed RNA from the virus in their feces.”
The report added that RNA from the virus can be detected in untreated wastewater “as many as three to seven days before those infections lead to increases in case counts or hospitalizations.”
Dompke said that about $8,680 has been spent on testing from October to December. The report states that after samples are collected, Columbus City Utilities sends them to Pace Analytical for examination.
“Samples are first processed to concentrate and isolate genetic material (RNA and DNA) that is present in the samples,” the report states. “Within the genetic material, RNA sequences specific to SARS-CoV-2 are then detected and quantified using a common molecular biology tool called Polymerase Chain Reaction (PCR). During PCR, targeted segments of two RNA sequences associated with the virus responsible for COVID-19 (N1 and N2).”
However, while the city has been having wastewater tested since October, both Dompke and Bowling said that a pattern has yet to emerge.
“I think as we develop these new theories and ways to analyze the data, I do think we’ll see a better trending pattern,” Bowling said. “It’s changing daily.”
Bowling’s report notes that various cities across the United States are reporting wastewater COVID-19 information in different formats, with no universal standard. Furthermore, the report added that the Centers for Disease Control and Prevention are recommending that community spread projections should not be based on “wastewater measurements”. More “clinical data” is needed to aid these estimates, the report said.
Another obstacle in COVID-19 wastewater analysis, as noted by the report, is that people infected with the virus can shed SARS-CoV-2 “for 20 to 30 days after they are no longer infectious”, meaning that the results of wastewater testing could lag in showing a decreased number of cases in an area.
However, the report did note that, “The CDC strongly encourages communities to use data to create and monitor the trends of viral gene copies detected in a community over time. Trends in viral gene copies should be considered along with community case numbers and other COVID-19 related data to inform decisions about taking actions to help limit disease spread.”
Dompke told the utility service board Thursday that he would like to continue testing wastewater for COVID-19.
“While we may not see patterns today, once we figure out the bigger picture of this stuff, this may be useful information,” he said.
Bowling’s report said that Columbus City Utilities will “continue to consult experts in this field across the country and gain insight on reporting the data” received from its sample results.
