Sewers4COVID from the University of Exeter: a team led by Professor Dragan Savic FREng applied machine learning to sewer epidemiology to estimate the number of infected people in a certain geographical area to track the spread of infection. ©thisisjude.uk 2020

Mass testing has proved challenging throughout the pandemic but an international team has developed an original approach for early detection of the SARS-CoV-2 virus by analysing wastewater.

Sewers4COVID could enable experts to quantify the presence of the virus in the population without the need for extensive and expensive individual testing.

Engineering contribution

Detecting the presence of coronavirus SARS-CoV-2 in the population is vital to control it, but individual testing can be expensive and invasive. A team of engineers at the University of Exeter, in collaboration with scientists from the Netherlands, Greece and Spain, developed a fresh approach for early detection of the SARS-CoV-2 virus by tapping into sewers.

The Centre for Water Systems team contributing to Sewers4COVID, led by Professor Dragan Savic FREng, includes Dr Lydia Vamvakeridou-Lyroudia, Professor Albert Chen, Dr Mehdi Khoury and Gareth Lewis.

They use wastewater-based epidemiology, which involves analysing sewage samples on a daily basis. This practice provides data for DNA sequencing technology using real-time quantitative polymerase chain reaction (RT qPCR).

By applying machine learning techniques to the sewer surveillance data, Sewers4COVID can detect hotspots of potential outbreaks in real time. The method also takes into consideration socioeconomic conditions, to identify vulnerable groups that are at high risk. The result is an estimate of the number of infected people in the area covered by the sewer system.

This ingenious approach was conceived in just 48 hours when the Exeter engineers competed with more than 2,000 other teams in the #EUvsVirus hackathon organised by the European Commission in April. Collaborating online , the team developed the methodology and a powerful prototype of a digital pandemic observatory at a countrywide scale in the Netherlands.

Impact

Sewers4COVID provides a powerful early warning system that can reveal infection even before people start showing symptoms. It can provide large-scale monitoring at a fraction of the cost of individual testing and it offers a cost-effective solution for long-term public health surveillance.

The team plans to develop the methodology into a decision support system to help experts choose the most effective mitigation measures to prevent or reduce the impact of future pandemics. 

Together with partners in Asia and South America the Exeter team is planning to adapt the Sewers4COVID approach for use in lower and middle-income countries with significantly different wastewater infrastructure, environmental and socioeconomic characteristics from European countries. The team is also part of the Europe-wide initiative “SARS-CoV-2 Surveillance employing Sewers EU Umbrella Study” by the EU Joint Research Centre (JRC)  to apply the concept to more than 90 wastewater treatment plants across the EU.

The Umbrella Study will build a digital pandemic observatory for monitoring the spread of COVID-19 within EU communities, which will strengthen public health management for coping with a possible second wave of COVID-19. The approach is generic, and could also help monitor the prevalence of antibiotic resistance, or understand the use and application of household chemicals such as detergents, disinfectants, personal care products or cosmetics, or monitor the use of illegal drugs in a particular area. The methodology is used only for monitoring purposes at a population level and raises few ethical concerns as individuals cannot be identified.

Durk Krol, Executive Director of Water Europe, says: “Sewers4COVID offers an alternative approach, which is independent of costly individual viral tests, for large scale-surveillance that provides scientifically-proven evidence to support public health management. It will quickly reflect the phase of virus concentration in communities, enabling governments to manage restrictions in a timely way with confidence.”