Testing sewage could predict local coronavirus outbreaks five days before they happen, scientists from Yale have found.
The new research found that testing waste from households can give an indication of an area at risk of a coronavirus outbreak that could require lockdown.
Their results found that the detection of the viral strain of Covid-19 in sewage leads to hospital admissions in an average 4.6 days.
The scientists said that their model provides an earlier indication of where coronavirus is growing in the community than data from hospital admissions.
Scientists said that advances in the UK’s testing programme such as these could lead to much quicker identification of the coronavirus, meaning the Government can act quicker to lockdown areas.
Brian Neve, Non Executive Director of Spiro Control, and a practicing process control engineer, said that trials such as these show that “waste water epidemiology should be used as early warning, some of them are confident about prediction numbers and hence indicate that it can be used for policy decisions.
“In future better and more upstream waste water sampling could result in even faster detection further reducing the delays.”
Work has been quietly ongoing on this since March in the UK, with the Department for Environment, Food & Rural Affairs (Defra) leading on the effort in sampling in 44 sites across England.
Their hope is that this data will feed into the Covid-19 alert system, alongside local testing, and allow for the Government to act swiftly in it’s “whack-a-mole” local lockdowns.
Where this new tool to combat coronavirus comes into its own is its ability to detect those who are asymptomatic and pre-symptomatic - one of the major barriers in the Government’s current testing programme.
Dr Alex Corbishley is leading research from the University of Edinburgh's Roslin Institute testing waste water for signs of Covid-19
He told the Sunday Telegraph that currently we suspect that people are infectious before they show clinical signs, and that these people could be found early by sewage testing.
“If we think we think about our testing currently, there's a little bit which is done randomly across the population, the vast majority is done on suspicions such as having a cough or a temperature,” he said.
“The testing of the population is heavily biased to those with clinical signs. But we know children in particular and most people under the ages of 30 to 40 are at very low risk of clinical signs.
“Many people will get it and not even know we have it at all. Those people are the ones which waste water testing are going to pick up before you get people in a hospital.
“You have parts of the population transmitting the virus and they don't know that they're doing it, but this could spill over into higher risk people and cause them to be sick, which then causes hospital admissions.”
As well as its applications to finding coronavirus, scientists have used this sewage method to test for polio for three decades, and have been able to estimate where the virus is circulating, how serious the outbreak is, and where it has come from.
The hope is that it can now be used as an integral part of the UK’s testing network, even helping with the outbreaks of flu which presents new challenges for the health system when combined with a potential second wave over winter.
“This is one tool in the toolbox and we need as many tools as we can. The challenge is: how do you monitor 66 million people?” says Dr Corbishley.
“To continually monitor that many people only on symptoms is unreliable, as we have a significant number of people that don't display symptoms.”
“Going into the autumn now, there are other uses for this - one of them is influenza and this is detectable in waste.
“One concern is how influenza interacts with coronavirus and now we will be able to see if we can find them together in communities.”