Wastewater-based epidemiology for public health - benefits and trade-offs of different molecular methods for the generation of actionable data in a small-town context.

BackgroundWastewater-based epidemiology (WBE) is a promising complement to traditional surveillance systems, yet its practical utility and performance in real-world public health settings remain insufficiently characterized. This study aims to evaluate the feasibility and added value of WBE for monitoring infectious disease dynamics at the regional level, with a particular focus on jointly identifying, together with public health authorities, actionable and scalable methodological strategies based on cost, applicability, and the relevance and timeliness of the information generated.MethodsComposite influent wastewater samples were collected over 6 weeks from a treatment plant serving a defined district in western Germany. Samples were analyzed using quantitative PCR and both targeted and shotgun metagenomic sequencing. WBE findings were compared with routine case-based surveillance data from the corresponding catchment area.ResultsAll pathogens reported through routine public health surveillance during the study period were also detected in wastewater. In addition, WBE identified signals from clinically relevant pathogens not captured by case-based surveillance. Sequencing approaches provided further resolution on pathogen diversity and resistance profiles. The combined use of targeted and untargeted methods revealed differences in sensitivity and resolution, with complementary strengths across approaches, and enabled the definition of a practical, tiered approach to support actionable surveillance at the regional level.ConclusionThis study describes the operational integration of WBE into a regional public health workflow, providing timely, population-level data that complements routine surveillance and can reveal pathogen circulation not captured by reported cases. Building on the established advantages of WBE, our results highlight its practical value when jointly implemented with public health authorities, enabling context-specific, actionable insights that enhance situational awareness, guide targeted local responses and support earlier detection of emerging threats.