Advancing wastewater surveillance through cross-border collaboration: A workshop summary

Wastewater surveillance (WS) emerged as a valuable tool during the COVID-19 pandemic, complementing clinical and syndromic data to render unbiased, evidence-informed decisions about community health.Across North America, WS networks were established; however, as the pandemic has receded, provincial, state and federal support for this tool has declined, even though there are still concerns about emerging threats, like avian influenza and a generational-scale measles outbreak that affected Canada and the United States (US) in 2025.In May 2025, organizers convened the "Cross-border Collaboration to Advance Wastewater Surveillance" workshop to reinforce the importance of WS beyond COVID-19 and the need to communicate data effectively across jurisdictional boundaries.The workshop brought together researchers and public health practitioners from across Canada and the US to discuss the current state of WS networks and opportunities for cross-border collaboration in areas of pandemic preparedness and data management.Key findings coalesced around a need for WS networks to harmonize methodologies and data sharing approaches, to coordinate with emergency preparedness and alert-response protocols and to integrate wastewater data within existing clinical and syndromic disease surveillance systems.A tabletop exercise highlighted a disconnect between pathogen detection in wastewater and actionable public health interventions, reinforcing the need for standardized interpretation frameworks and decisionmaking protocols.Last, researchers and public health practitioners must continue to advocate for support to advance the methods and promote applications of this novel cost-effective tool in the surveillance of infectious diseases.