Wastewater-based surveillance is moving from ad hoc use during health emergencies to a more structured role within infectious disease surveillance across the EU and EEA. New legislative requirements that entered into force in early 2025 have made wastewater sampling mandatory for multiple public health purposes, creating both opportunity and obligation for Member States. Against this backdrop, the European Centre for Disease Prevention and Control has set out a framework to guide how wastewater-based surveillance can be systematically integrated into infectious disease surveillance and public health decision-making at EU and national levels. The framework reflects growing experience since the COVID-19 pandemic, acknowledges uneven implementation across countries and outlines how wastewater data can complement established clinical and epidemiological systems while addressing operational, legal and scientific challenges.
From Environmental Signal to Public Health Data
Wastewater-based surveillance refers to the analysis of urban wastewater to detect pathogens or related health indicators shed by a population. Unlike clinical testing, which depends on healthcare access and individual testing behaviour, wastewater data provide aggregated, population-level signals. The framework emphasises that wastewater surveillance is not new, having been used for decades in poliovirus monitoring, but its scope has expanded with advances in laboratory methods such as PCR and metagenomics. These approaches allow detection of viral and bacterial material and, in some cases, genetic variants.
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The document underlines that wastewater data should not be interpreted in isolation. Its value lies in complementing indicator-based and event-based surveillance systems, particularly where clinical data are limited or delayed. Pathogens such as polioviruses, SARS-CoV-2 and influenza viruses are highlighted as areas where wastewater monitoring can add sensitivity, support trend analysis and contribute to early warning. However, the framework is clear that wastewater systems must be designed around defined public health needs, with careful consideration of sampling strategies, data normalisation and comparability across sites.
Building a Coordinated EU and National Infrastructure
A central element of the framework is coordination. The level of wastewater surveillance implementation has varied across EU and EEA countries, often relying on time-limited projects with differing coverage and sustainability. To address this, ECDC proposes the creation of an EU and EEA wastewater-based surveillance network within its existing Coordinating Competent Bodies structure. This network would bring together nominated national experts, ideally linking public health authorities with environmental and wastewater sector counterparts.
Laboratory capacity is another focus. ECDC plans to provide support activities aligned with its established procedures, including external quality assessments, training, reference services and method harmonisation. These measures aim to improve data quality and comparability, which are essential for meaningful EU-level analysis. The framework also recognises the need for continued investment in human resources and infrastructure at both national and EU levels to sustain these systems beyond emergency contexts.
Data integration is described as a critical bottleneck. Effective use of wastewater surveillance requires automated, real-time access to electronic data. Current EU-level data collection is considered insufficient, particularly in light of new reporting obligations under the recast Urban Wastewater Treatment Directive. The framework outlines plans to identify suitable databases and reporting platforms, with existing ECDC tools such as EpiPulse being explored for structured and event-based wastewater data submission. Avoiding double reporting and ensuring efficient data flows are presented as key principles.
Public Health Use, Preparedness and Limitations
The framework sets out how wastewater-based surveillance can support infectious disease surveillance across routine monitoring, outbreak detection and preparedness. Its strengths include the ability to detect unusual events, track pathogen trends and support genomic surveillance, including the monitoring of variants or antimicrobial resistance markers. Wastewater data can also inform the evaluation of public health interventions by showing changes in pathogen levels over time.
At the same time, the document is explicit about limitations. Wastewater surveillance delivers population-level signals and cannot replace clinical data for assessing individual risk factors, disease severity or outcomes. Interpretation is affected by variability in pathogen shedding, environmental degradation and infrastructure factors such as sewer design and treatment processes. As a result, wastewater data must be contextualised with other surveillance streams to avoid misinterpretation or overreliance.
Preparedness is a recurring theme. Flexible wastewater systems can be adapted during outbreaks or pandemics by increasing sampling frequency, adjusting population coverage or adding new targets. The framework notes applications ranging from monitoring high-risk settings such as long-term care facilities to surveillance during mass gathering events or at points of entry like airports. These uses support early warning and situational awareness when clinical surveillance is constrained or delayed.
The ECDC framework positions wastewater-based surveillance as a complementary, not standalone, component of infectious disease surveillance in the EU and EEA. By setting out governance structures, laboratory support, pathogen prioritisation criteria and data integration pathways, it seeks to move wastewater monitoring from fragmented initiatives to a sustainable public health asset. For healthcare professionals and decision-makers, the framework clarifies both the potential and the boundaries of wastewater data, reinforcing the need for coordinated investment, cross-sector collaboration and integration with established surveillance systems. As new legislative requirements take effect, the framework provides a structured basis for translating environmental signals into actionable public health intelligence.
Source: European Centre for Disease Prevention and Control
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