Sewage study indicates thousands more COVID-19 cases in Chattanooga than reported

Staff photo by Troy Stolt / Moccasin Bend Wastewater Treatment Center, as seen on Saturday, March 28, 2020 in Chattanooga, Tenn.

A study last month of Hamilton County's wastewater for evidence of COVID-19 infections is showing thousands more cases in the community than publicly reported.

The data - part of an ongoing study of the coronavirus in sewage - reported 8,200 cases of COVID-19 in the county on July 21, a time when the Hamilton County Health Department reported 4,461 confirmed cases.

The information from July 21 is the fifth data point in the city's ongoing sampling of wastewater, showing varying levels of cases in the community. On May 18, the company doing the study, Boston-based Biobot Analytics, reported 1,700 cases in Hamilton County. On May 26, the company reported 12,500 cases. Then, on June 23, the company reported 4,400 cases before the number jumped again to 8,800 cases on July 7 and 8,200 cases on July 21.