Researcher Finds Possible COVID Warning in Sewage

Jul 9, 2020

Testing for the coronavirus is ongoing throughout the country, but testing individually takes a lot of time.  University of South Carolina public health Professor Sean Norman is taking a different approach.  Viruses are not only carried in the body, but some are also shed in human waste, and coronavirus is one of them.  So Norman is analyzing sewage to determine the presence and amount of the virus in large populations.  He said the application is new, but the technique has been around for a while.

"People have looked at wastewater to monitor other viruses, like polio virus, as well as pharmaceuticals, illicit drugs as well as opioids and other types of pharmaceuticals.   So when the coronavirus pandemic hit, it would be an obvious transition into understanding if we can use wastewater to monitor the prevalence of the virus within community settings."

Norman had already been studying wastewater for about two years, and has worked with the South Carolina Department of Health and Environmental Control (DHEC) and the Center for Disease Control (CDC) in Atlanta, which suggested the project.  The three formed a partnership.  DHEC collects samples from eight wastewater facilities around the state and transports them to Norman's laboratory, where they are analysed.  

What, and how much, Norman finds is what's important.  According to Mike Marcus, chief of DHEC's Bureau of Water, "the hypothesis is by looking at the concentration of virus in waste water, that hopefully, we'll be able to use that as a predictor of an imminent upturn in COVID cases in the area that's served by that wastewater treatment facility.  And if this hypothesis is proven, it wil be transportable to other treatment facilities.  So it would be an early detection, early warning tool that we think would then hopefully provide some benefit to the public health decision makers in their management of a COVID event." 

The research is still in its early stages, but the signs are hopeful, said Norman.  "This could be a predictive indicator to be able to understand if we're seeing future waves of the virus coming before it actually overwhelms a medical system."  

If the early indications hold, the virus found in wastewater could give scientists a lead time of at least a week to prepare for spikes of COVID.  Norman said the CDC is "very interested in developing this into a model that might be used at a national level at some point.  So we're feeding data to their epidemiologists and their modelers."

"The purpose is to give them one more tool, one more piece of information to help them make more informed decisions," said Marcus.  "That perhaps could then lead to focused testing, pre-testing, increased testing in certain areas.  Positioning of supplies and equipment.  Things that are part of a natural public health response." 

Norman added that the data also could be used to determine when policies are working, and the number of COVID cases is shrinking.  "So you can not only monitor upward trends, you can monitor downward trends as well.  You can use it as a means of trying to understand when certain policies are put in place, how that might be impacting the abundance of the virus through up or downward trends." 

Marcus said when the research is confirmed, South Carolina's - and America's - citizens will be the beneficiaries of improved public health.