What You Should Know About the CDC Wastewater COVID Testing Program

key takeaways

  • CDC is adding wastewater surveillance data to its COVID-19 data tracker to help provide early signs of rising virus rates in the community.
  • This information can be used to better allocate resources, such as testing locations and hospital supplies.

As Omicron rates in the U.S. drop and states begin to lift mask regulations, public health experts are figuring out how best to remain vigilant against any new outbreaks and variants of COVID-19.

One way is to monitor wastewater in the community. The Centers for Disease Control and Prevention (CDC) recently announced that the agency is expanding its nationwide efforts to detect COVID-19 outbreaks early by examining community wastewater for the virus.

The CDC made the announcement during a conference call with reporters on February 4, 2022.

“Estimates show that 40 to 80 percent of COVID-19 patients shed viral RNA in their feces, making wastewater and sewage an important opportunity to monitor the spread of infection,” said National Health Service team leader Dr. Amy Kirby. CDC’s wastewater monitoring system during the call.

Wastewater is collected by utility workers and then evaluated at state and CDC laboratories.

How wastewater testing can help stop community spread of COVID-19

Kirby said that while the CDC launched the National Wastewater Surveillance System (NWSS) at hundreds of sites in September 2020, it is only now adding wastewater monitoring data to the agency’s COVID data tracker site so people can see it trends in their community.

“The true power of the program will become more apparent in the coming weeks when hundreds of test sites begin submitting data,” Kirby said. “Because increases in wastewater often precede a corresponding increase in clinical cases, wastewater surveillance can serve as an early warning system for the emergence of COVID-19 in the community.”

Kirby told reporters that people infected with COVID-19 typically shed large amounts of the virus in their feces early in the infection, but much less as the infection progresses. Infections can be detected even in asymptomatic people, which is why wastewater monitoring is such a valuable tool.

Over the next few months, the CDC expects to have enough sites reporting data to get information on most state, territory and tribal communities.

How Wastewater Testing Improves COVID Response

A key reason why wastewater monitoring is particularly important right now is the increasing turn to at-home kits to test for COVID-19. Their results are not typically reported to state labs, so community levels of COVID-19 may appear lower than they actually are.

Should you report your COVID-19 home test results to your local health department?

Wastewater testing also helps public officials understand where to allocate resources. Public health experts can better understand where to send mobile testing and vaccination sites if COVID-19 is present at a given site.

“We use this information to decide where we will prioritize interventions in areas where wastewater data in certain parts of the city tells us that infection rates are higher,” Dr. Loren Hopkins, chief environmental science officer at the Houston Health Authority, told VigorTip.

“The pattern is that you see an increase in wastewater first, then the positivity rate (of COVID tests), and then the hospitalization rate,” she said. “So wastewater testing is a bellwether of what’s going on.”

what does this mean to you

Wastewater surveillance data is often used by public health staff at the community level, but individuals can find information for their state and many communities on the CDC website. Signs of rising rates can help you decide if you need to be more vigilant about wearing masks, social distancing, and close contact with others.

The information in this article is current as of the date listed, which means that you may have updated information as you read this article. For the latest updates on COVID-19, visit our Coronavirus news page.