CDC National Wastewater Surveillance System (NWSS)

NWSS is a U.S. public-health surveillance program that monitors pathogens in wastewater to detect community-level disease trends. It detects viral genetic material (RNA/DNA) from pathogens such as SARS-CoV-2, influenza A, RSV, mpox, and others, providing an early warning signal for outbreaks before increases appear in clinical testing data. Wastewater monitoring is an effective model that works because infected individuals shed pathogens in stool and other bodily fluids that enter sewer systems, allowing population-level detection without individual testing.