Without the capacity for large-scale testing of each person individually, particularly those who don’t show any symptoms, there is limited information about how widespread Covid-19 is or whether it is affecting some communities more than others.
A team of scientists at Newcastle University have turned to wastewater epidemiology as a way of detecting the prevalence of the virus.
By analysing sewage to monitor for genetic residues of SARS-CoV-2, the virus that causes Covid-19, they are playing a key role in researching and developing a standardised UK-wide system for tracking future outbreaks.
This is part of a nationwide programme to develop sampling, testing and scientific modelling methods that will be adopted by government agencies and public health experts across the UK to provide an early warning of potential outbreaks. In turn, this will help to reduce reliance on costly testing of the wider population.
About the research
The work at Newcastle, which has attracted national and international attention, is being led by Professor David Graham, in collaboration with partners at Northumbrian Water.
Professor Graham, who is also a member of the Transmission in Wider Environment Group (TWEG) providing guidance to the UK Scientific Advisory Group for Emergencies (SAGE) during the current Covid-19 pandemic, explains: “Sewage epidemiology is now being used around the world as way of assessing Covid-19 at community scales."
"Our work at Newcastle has especially focused on exact developing methods for predicting virus prevalence as an early warning system.”
The research has been funded by the Natural Environment Research Council (NERC) as part of UK Research and Innovation’s rapid response to Covid-19. Led by the UK Centre for Ecology & Hydrology (UKCEH), Graham’s team is working with experts at the universities of Bangor, Bath, Edinburgh, Cranfield, Lancaster, Oxford and Sheffield, plus the London School of Hygiene and Tropical Medicine.
“This project has exceptional potential because it brings together experts with different backgrounds from across the country, and is explicitly addressing key knowledge gaps in sewage surveillance, especially improving the accuracy of virus quantification, which is central to our work here,” adds Professor Graham.
Monitoring early signs through wastewater
SARS-CoV-2 does not readily spread through sewage and wastewater systems. However, non-infectious genetic residues of the virus can remain in wastewater systems in the locations where infected people go to the toilet.
Sampling and analysing wastewater across a sewage collection network allows researchers to identify specific locations with higher levels of virus shedding, which implies more Covid-19 cases. However, because shedding occurs almost immediately after infection, virus in sewage tells you where cases exist before they are symptomatic, enabling public health officials to quickly develop interventions in areas of greatest exposure risk.
The work by the team at Newcastle builds on a similar project funded by the Engineering and Physical Sciences Council (EPSRC), which they carried out with scientists from the University of Santiago de Compostela and water industry partners Northumbrian Water and Labaqua, part of the SUEZ corporation, to develop a way to more exactly quantify the prevalence of the Covid-19 virus across areas in north east England and Spain.
“SARS-CoV-2 is substantially different from commonly monitored viruses in the environment and methods to track it have not yet been standardized,” says Dr Marcos Quintela-Baluja, part of the Newcastle University team. “Measuring SARS-CoV-2 in sewage is more difficult than clinical samples, which is why we are focusing on developing accurate methods.”
Northumbrian Water’s Wastewater director, Richard Warneford, adds: “We’re proud to be working with our partners at Newcastle University on this globally significant project. Our wastewater teams are working with their engineers and scientists to safely gather and analyse data and we’re hoping that together we can help make a difference in the battle against Covid-19.”
All of this is just the beginning. Newcastle University are scientific advisors on the “Core Cites Project”, comparing Covid-19 spread using sewage from eight cities across the UK.
We are now studying SARS-CoV-2 and other infectious disease markers, such as antibiotic resistance, in wastewater coming from prisons and food production facilities – extending wastewater epidemiology into the future, beyond the current pandemic.
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