In response to the COVID-19 pandemic, CDC launched the National Wastewater Surveillance System (NWSS) in September 2020. CDC developed NWSS to coordinate and build the nation’s capacity to track the presence of SARS-CoV-2, the virus that causes COVID-19, in wastewater samples collected across the country.
CDC’s NWSS works with health departments to track SARS-CoV-2 levels in wastewater so communities can act quickly to prevent the spread of COVID-19. NWSS is transforming independent local efforts into a robust, sustainable national surveillance system.
People infected with SARS-CoV-2 can shed the virus in their feces, even if they don’t have symptoms. The virus can then be detected in wastewater, enabling wastewater surveillance to capture presence of SARS-CoV-2 shed by people with and without symptoms. This allows wastewater surveillance to serve as an early warning that COVID-19 is spreading in a community. Once health departments are aware, communities can act quickly to prevent the spread of COVID-19. Data from wastewater testing support public health mitigation strategies by providing additional crucial information about the prevalence of COVID-19 in a community.
Data from wastewater testing are meant to complement existing COVID-19 surveillance systems by providing:
- An efficient community sample
- Data for communities where timely COVID-19 clinical testing is underused or unavailable
- Data for different communities within a county