Wastewater surveillance: how does it work and why do we need it

Wastewater and environmental surveillance (WES) refers to a systematic approach for monitoring and analysing wastewater, as well as environmental samples such as surface water, sewage, and sludge, to detect and track the presence of pathogens, pollutants, contaminants, or other indicators of public health and environmental risks. WES involves collecting samples from various sources within a community, a geographical area, or strategic locations, followed by laboratory analysis to identify and quantify specific substances or microorganisms of interest. By integrating data from human, animal, and environmental sources, WES provides valuable insights into disease transmission and spreading dynamics, environmental contamination, and potential health risks to both humans, plants and animals, fully substantiating the One Health approach. One of the primary reasons for the adoption of wastewater surveillance is its ability to provide population-level insights into disease prevalence and transmission dynamics, therefore complementing other surveillance methods.

During the COVID-19 pandemic, wastewater surveillance and related epidemiological assessments became essential for gathering timely and relevant information, regardless of testing availability or intervention efforts. By analysing virus levels in sewage, similar trends to clinical cases were observed, highlighting its importance as an additional tool for tracking SARS-CoV-2 and its variants in different areas. Urban sewage systems and wastewater from transportation hubs like airports emerged as key locations for monitoring the spread of the virus, aiding in understanding its territorial presence and transmission patterns.

In essence, wastewater surveillance represents a valuable tool in the public health arsenal, offering a cost-effective, scalable, and non-invasive approach to provide early warnings of outbreaks before clinical cases are reported, helping authorities implement timely interventions.

HERA’s activities in the wastewater surveillance field

While wastewater surveillance plays a key role in health preparedness, its full pandemic preparedness potential is yet to be unlocked. This is why the Health Emergency preparedness and Response Authority (HERA) is significantly investing in this field, by supporting activities at local, national and international level.

HERA is undertaking various initiatives, such as increased sampling of current supersites in the EU. But, what are supersites? A supersite is a specific sampling location where transportation hubs – such as airports, bus stations, ports – and households converge, making it particularly interesting from an epidemiological perspective. The information obtained from wastewater samples collected from these supersites is instrumental to provide early warnings of potential outbreaks. To further leverage this potential, HERA together with the Joint Research Centre (JRC), is linking all existing supersite and expanding to new ones in the effort of creating an EU sentinel system. With the support of the Joint Research Centre (JRC), HERA is also supporting the testing of these wastewater samples using PCR analysis and Next Generation Sequencing for different pathogens, when needed. To the same end, HERA provides support to Member States for specific sampling needs, such as devices for aircraft sampling. Finally,, the collaboration with JRC is pivotal for facilitating data exchange and the expansion of DEEP (the Digital European Exchange Platform), as well as organising training activities, such as the creation of the Wastewater surveillance academy.

In addition, HERA is supporting the Joint action EU-WISH, aimed to institutionalise wastewater surveillance for public health and supporting national strategies in this field. It is important to note that HERA's support extends beyond Europe, for instance to support to wastewater and environmental surveillance throughout the continent.

Moreover, HERA collaborates with the World Health Organization (WHO) and the United Nations Environment Programme (UNEP), especially to support the development of strategies, increasing of capacities, and data sharing for global wastewater and environmental surveillance.

All these activities, while being conducted independently, they all feed into a bigger effort. Indeed, HERA – in collaboration with several international stakeholders, such as the Bill and Melinda Gates Foundation – is building a global network of partners to further drive collaboration and innovation. By leveraging community-based surveillance alongside wastewater monitoring at strategic locations such as transportation hubs, GLOWACON seeks to establish a global sentinel system for epidemic outbreaks that enables early threat detection and real-time monitoring to support public health decision-making.

GLOWACON is a voluntary network of stakeholders eager to cooperate, collaborate, and build synergies based on their existing activities. It Is a collective endeavour grounded in a shared conviction about the power of wastewater surveillance to support public health decision making. HERA is proud to be leading this ambitious endeavour, which is expected to result in an efficient tool for improving public health globally.