From Sewers to Surveillance: Monitoring Salmonella Through Wastewater

Wastewater surveillance (WWS) is a powerful, population-level approach to infectious disease monitoring that complements traditional clinical surveillance, which often under-detects asymptomatic or unreported cases. This study presents validated methods for Salmonella detection in wastewater, including sample concentration using PEG precipitation, nucleic acid extraction with magnetic beads, and quantitative PCR targeting. When WWS for Salmonella was implemented across Oklahoma from 2021 to 2022, results showed seasonal patterns in transmission, provided a 1-week lead time over clinical case reporting, and identified outbreak activity not captured through passive surveillance. Although challenges remain, such as low pathogen levels and limited serovar resolution, WWS demonstrates strong potential for early warning, outbreak detection, and improved understanding of Salmonella dynamics when integrated with traditional public health systems.