Implementing wastewater surveillance for viral pathogens: lessons learned from SARS-CoV-2, monkeypox virus, norovirus and influenza A viruses

Wastewater surveillance is a valuable and noninvasive way to detect, monitor and rule out viral pathogen transmission at the population level. Drawing on lessons learned from severe acute respiratory virus two (SARS-CoV-2), monkeypox virus, norovirus and influenza A viruses, we outline six key considerations for designing or refining a wastewater surveillance program for a viral pathogen: pathogen suitability, surveillance objective, sampling strategy, molecular assays, data transformation, and analysis. Together, these components form an interdisciplinary “wastewater toolkit” that supports methodological rigor, adaptability, and comparability across settings. By providing a structured yet flexible framework that accommodates technical variation and contextual differences, this toolkit enhances preparedness and enables the rapid establishment or optimization of wastewater surveillance systems. Gaps and inefficiencies in disease surveillance can lead to inaccurate intelligence and inadequate or inappropriate public health responses, a systematic wastewater surveillance framework is essential to generate reliable indicators of viral transmission and inform timely, evidence-based decision-making for known and emerging pathogens.