About a third of wastewater sampling sites across the U.S. are showing an uptick in COVID-19 cases, according to data from the Centers for Disease Control and Prevention (CDC).
In the 15-day period running from Feb. 24 to March 10, 145 wastewater sampling sites out of 401 active sites revealed an increase of 10 percent or more in coronavirus wastewater levels, the CDC data table shows.
Sixty-two of those sites showed an increase of 1,000 percent or more, while 48 increased anywhere from 100 percent to 999 percent.
Bloomberg reported on Monday that a 10-day detection of COVID-19 at the sampling sites from March 1 to March 10 was much higher than the period running from Feb. 1 to Feb. 10, although during that period fewer sites were available for testing.
The CDC last month announced its National Wastewater Surveillance System was now publicly available through its COVID-19 data tracker on the agency’s website. The system first rolled out in 2020.
Examining wastewater through household and building toilets, showers and sinks, as well as non-household sources like rain and industrial uses, does not identify confirmed cases but provides an early warning about the rise of COVID-19.
Amy Kirby, the program lead for the CDC’s National Wastewater Surveillance System, said last month that 40 percent to 80 percent of people who have COVID-19 shed viral RNA in their feces.
Confirmed coronavirus cases have largely dropped across the U.S., leading to the lifting of mask requirements and COVID-19 restrictions across.
The latest CDC data shows a large downward trend of confirmed cases, while 81 percent of Americans ages 5 and up have received at least one dose of a COVID-19 shot.