Wastewater tests show COVID-19 increase

Tests of wastewater facilities in Cape Girardeau, Perryville and Sikeston, Missouri, show the highest amount of COVID-19 detected in the area in months.

Since July 2020, the Missouri Department of Health and Senior Services has been working in collaboration with the state Department of Natural Resources and the University of Missouri on The Sewershed Surveillance Project.

The program coordinates with local agencies to test wastewater facilities for COVID-19 viral loads across the state. The program enables scientists to detect COVID-19 in populations without needing clinical tests and is able to detect COVID-19 even in asymptomatic cases.

Tests are conducted weekly and viral load is determined based on the exponentially weighted average (EWMA) of the number of viral marker copies per day, due to viral shedding that occurs for up to 30 days after infection in human waste.

Cape Girardeau Municipal Wastewater Treatment Facility was marked by the monitoring program as a facility with increasing viral load, along with Perryville Wastewater Treatment Plant and the Sikeston Waste Water Treatment Plant.

Viral loads must increase by 40% in one week or 25% over the previous two weeks for it to be placed in the category. Cape Girardeau went up more than 160% between July 4 and July 11. Sikeston increased around 120% between June 27 and July 11. Perryville had by far the largest increase, growing 270% in just a week.

For Sikeston and Cape Girardeau, it's the largest viral loads dating back to February and for Perryville it's the largest since January.

The increase in load does not always correlate with an increase in cases, according to the program website. However, there has been an increase in cases, particularly, in Cape Girardeau County and Scott County. Both are placed in the high risk community level by the Centers for Disease Control and Prevention. Perry County is currently in the medium risk category.