Arup’s Olivia Bailey, Digital Water Consultant and Project Manager for Wastewater for Health, explores how monitoring biomarkers in wastewater has the potential to be the “canary in the coalmine” to provide an indication of human health for any future pandemic.

Olivia Bailey:  It is often said that crises force breakthroughs in technology, and it is true that these breakthroughs can improve our lives long after the event has passed. Take the military advances of World War II, which in many minds, paved the way for huge technological leaps - from computers to modern day weather forecasts.

Fast forward to January 2020, when the world’s population was caught off guard by a pandemic that upended our lives. Like previous crises, the pandemic forced technological developments in all sectors, especially healthcare. One such area was in the field of wastewater-based epidemiology (WBE): a process of monitoring biomarkers found in sewage to provide an indication of human health. 

WBE has the potential to be the ‘canary in the coalmine’ for any possible future pandemic, giving policymakers critical advance warning to be able to prepare, or even the opportunity to nip an infectious disease in the bud altogether. Over the last few years, WBE has proved to be an invaluable tool in the fight against COVID-19, helping to predict new waves and strains of the virus and guide healthcare responses in the UK and in other developed nations.

At present, the technology is not being utilised to its fullest potential in lower-middle and low-income countries. To extend the benefits of WBE to these countries, Arup - in partnership with researchers from University of Bath, Newcastle University and Bangor University – has developed a global framework to support stakeholders with limited resources to set up wastewater monitoring programmes in countries with varying degrees of sewerage infrastructure.

Wastewater for health

WBE offers policymakers around the world a powerful tool to assess various health markers, such as infectious diseases, antimicrobial resistance, pharmaceutical consumption and allows monitoring of their environmental interactions. This is achieved through collecting anonymised and ‘honest’ data on the health of society, including factors such as disease prevalence and lifestyle choices. Humans secrete biomarkers which indicate their health status many days before any potential symptoms are likely to develop.

By analysing these markers found in sewage, we can provide an early warning system for disease outbreaks and deliver monitoring insights to help inform governance and health strategies. It can also be used alongside other clinical data to guide healthcare responses or advise policy development, for example city-scale WBE was used in the UK during the COVID-19 pandemic to control the spread of the virus. 

WBE in the fight against COVID-19

WBE’s introduction to several developed nations during the COVID-19 pandemic proved invaluable as health and policymakers navigated the spread of the virus. Whilst the technology is becoming more popular across developed nations, only 16% of global wastewater monitoring sites are in lower-middle and low-income countries. WBE holds the potential to work as an earlywarning sign for some of the world’s most vulnerable and remote communities, to prioritise limited resources and preventative healthcare, and target health interventions to the areas that need it most. For example, researchers in Jaipur used WBE to successfully predict a second wave of COVID-19, despite a fragmented sewer system in much of India, by sampling nine treatment facilities.[1]

AWBE framework to improve global public health

To implement a WBE programme, there are a few considerations when it comes to the region’s infrastructure and capabilities. Our framework considers five key areas:

Infrastructure classification - local stakeholders must be aware of, and can define, a discrete number of wastewater infrastructure types that could be monitored. Within the framework, nine classifications of global wastewater systems have been defined in collaboration between EAWAG (Swiss Federal Institute of Aquatic Science and Technology) and IWA (International Water Association). By identifying the appropriate infrastructure that is in place, it can help inform the most suitable WBE technologies

Sampling methodology - the next consideration is to assess what kind of wastewater samples could be retrieved in each monitoring site. Questions local stakeholders should be asking include what to sample i.e., the health markers of interest and where to sample for the health marker to be a suitable representation of the population

Degree of testing capability - once the sample and testing sites have been identified, the testing capability must be defined. Depending on the health marker of interest (viral, bacterial and/or chemical) there are a series of options available, each varying in complexity, which can be used to analyse a wastewater sample 

Information outcomes - before implementing a WBE system, it is important for local stakeholders to discuss the outcomes that could be achieved through each testing and sampling scenario. The impact that can be achieved with a WBE programme is dependent on the sampling strategy and how the acquired data is analysed to produce suitable information that can inform decision making. It is therefore crucial to consider the likely outcomes achievable in the specific local context

Reflections on non-infrastructure factors - social context is paramount to any WBE approach, and so stakeholders involved with its implementation must consider the non-infrastructure factors, such as community behaviours, governance and other stakeholders, which may support or challenge a WBE system in these contexts. 

Unlocking the potential of WBE 

The value of wastewater-based epidemiology as a global health monitoring system has been proven in the last couple of years during the COVID-19 pandemic. However, the approach has so far been predominantly used in developed nations with more advanced sewerage infrastructure, and little is known about its potential in low-resource settings. In order to unlock WBE’s full potential, there needs to be a concerted push from governments, funding agencies, academia, non-government organisations (NGOs) and the private sector to start a conversation about its use in low-and middle-income countries, and how it can transform global health and policy development. To do this, engagement and coordination between health authorities and other stakeholders involved in the implementation will be key.

As more countries implement the system, it will be crucial to share insights gained from wastewater monitoring, contributing to a collective effort to improve human health. We are faced with a golden opportunity to roll out an early warning system for future health emergencies, but we cannot do it in silos. If we can work together to rollout this technology globally, the prize for us is a more resilient and safer future.

[1]Successful Application of Wastewater-Based Epidemiology in Prediction and Monitoring of the Second Wave of COVID-19 in India with Fragmented Sewerage Systems- A Case Study of Jaipur (India) medRxiv September 13, 2021. DOI: 10.1101/2021.09.11.21263417