An infographic titled “National Wastewater Surveillance System helps public health officials better understand COVID-19 trends in communities.” from the U.S. Centers for Disease Control and Prevention (CDC). The National Wastewater Surveillance System (NWSS) is a public health tool that can be used to detect and prepare for increasing cases of COVID-19 in communities. It works by testing wastewater samples for the presence of the virus. People with COVID-19 can shed the virus in their feces, even if they don’t have symptoms. This means that wastewater surveillance can be used to identify communities where COVID-19 is circulating, even if those communities are not seeing a high number of reported cases.

The NWSS is a collaborative effort between the Centers for Disease Control and Prevention (CDC), state, tribal, local, and territorial health departments, and wastewater treatment plants. Wastewater treatment plants collect samples of wastewater and send them to laboratories for testing. The laboratories test the samples for the presence of the virus using a variety of methods. The results of the tests are sent to the CDC and to state, tribal, local, and territorial health departments.

Public health officials use the NWSS data to better understand COVID-19 trends in communities and to make decisions about how to allocate resources, such as testing and vaccination sites. For example, if public health officials see an increase in the amount of the virus in wastewater samples from a particular community, they may decide to send a mobile testing unit to that community.

The NWSS is a valuable tool for public health officials in their efforts to track and respond to the COVID-19 pandemic.