LINCOLN, Neb. (Nebraska Examiner) — Call it “CSI of the sewers,” but public works employees in Lincoln, Omaha and at least 11 other Nebraska communities are conducting surveillance of city wastewater to track the incidence of COVID-19.
The testing is a relatively new thing in the world of public heath and is giving epidemiologists and other health officials a new tool to track the spread of the coronavirus and decide best strategies to deal with it.
Scott Holmes of the Lincoln-Lancaster County Health Department said a rise in COVID-19 in wastewater has been an early warning that an increase in positive tests is coming in the community.
“It’s an additional test that gives us a little better heads up” on what’s ahead, Holmes said.
He was among Lincoln officials who conducted a tour Monday to explain how samples are drawn at Lincoln’s Theresa Street Wastewater Treatment Plant, which is located along the Salt Creek near 27th and Cornhusker.
For the past year in Lincoln, a machine at the treatment plant has drawn a sample from incoming wastewater every half hour.
Every day, a 5-liter jar of wastewater is removed from a refrigerated storage area on the machine.
Lab in Massachusetts
Then, three 50-milliliter vials of liquid are drawn off and shipped overnight every Tuesday to a testing lab, Biobot Analytics, in Cambridge, Massachusetts. That firm was co-founded by a Massachusetts Institute of Technology (MIT) student interested in the potential of “wastewater epidemiology.”
By Thursday or Friday, Lincoln health officials said they have a report back on how prevalent the COVID virus is in the Capital City’s wastewater.
Holmes said that since the testing began, the highest peak was in January, when COVID registered more than 3 million “viral copies” per liter of water.
More recently, there was a rise in COVID cases in April, which raised readings in Lincoln to about 713,000 viral copies. The most recent tests, though, have been in the 600,000 range, Holmes said.
Testing costs $350 a week
The testing costs $350 a week, or about $18,200 a year, in Lincoln, an expense that is being picked up by federal coronavirus relief funds.
Holmes said the data is especially valuable since so many COVID cases go unreported now because of the prevalence of home tests — tests that don’t generate a report to the local health department. Also, a person who becomes infected and does not show symptoms may not report.
He said the Lincoln-Lancaster County Health Department looks at five other factors besides the wastewater test findings to determine the local response. Those include positive tests, the positivity rate, hospital usage and COVID deaths.
Holmes said it was difficult to estimate the percentage of unreported cases, but one study found that for every COVID case reported, three to five may not have been.
State has surveillance program
The Nebraska Department of Health and Human Services, in collaboration with the University of Nebraska-Lincoln and University of Nebraska Medical Center College of Public Health, began issuing statewide “surveillance reports” every week around the first of the year from 15 testing sites in 13 communities.
The state is also tracking the mutation and evolution of COVID-19 through “genomic” testing to determine which variants are present in Nebraska.
All the reporting stations showed spikes in coronavirus cases in early to late January, with some showing slight increases in April.
The cities participating in the testing, besides Lincoln and Omaha, are Atkinson, Chadron, Columbus, Fremont, Norfolk, Grand Island, Kearney, Hastings, North Platte, Scottsbluff and Wayne.
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