Scientists brand Government’s mass coronavirus testing ‘unsafe’ after Liverpool pilot results

Rapid coronavirus testing being carried out by the Government is ‘unsafe’ because the tests miss around half of infected people and let them go, scientists warn.

The lateral flow swab tests, which produce results in around 20 minutes, were found to only be half as accurate as proper lab tests in the November pilot in Liverpool. 

In a report of the trial Department of Health officials tried to claim success, writing: ‘These tests still perform effectively and detect at least 50 per cent of all PCR positive individuals.’

But independent testing experts have raged at the findings of the report, saying the tests are ‘not fit for purpose’ and could put lives at risk by falsely reassuring people that they don’t have Covid.

Professor Jon Deeks, a statistician at the University of Birmingham, said it was ‘absolutely urgent that [the Department of Health] halts implementation’.

Dr Duncan Robertson, a Covid-19 analyst at Loughborough University, called it a ‘big problem’ and said the use of the tests would ‘put vulnerable people at risk’.

Experts have raised concerns that the Government is using tests for purposes other than what they are meant for, with hopes of pinning social distancing rules on them and allowing people who test negative to follow looser rules.

But the Department of Health admits in its own report: ‘Some of the use envisaged by community testing may be outside the manufacturer’s instruction for use’.

In the report on Liverpool’s mass testing programme, which saw around half of the city’s 500,000 residents get tested over the course of a month, officials branded the scheme a success.

They wrote: ‘Frequently tests perform slightly less well in the field than in perfect laboratory testing condition… 

‘In field evaluations, such as Liverpool, these tests still perform effectively and detect at least 50 per cent of all PCR positive individuals and more than 70 per cent of individuals with higher viral loads in both symptomatic and asymptomatic individuals.’

Someone’s viral load is a way of quantifying how much of the virus they are carrying in their bodies. People with more are generally considered to be more likely to infect others because, as a result of having more inside them, they also shed more. 

The tests were compared by using both types on the people who get tested through the official route.

A PCR test is the lab test considered the gold standard, and the one offered to people who have symptoms of Covid-19.

Although raw numbers have not been published the document suggests that for every 10 people who tested positive using the PCR tests, only five showed up as positive in the rapid tests.

And these rapid tests were used on hundreds of thousands of people who did not get a PCR test alongside it, meaning numerous cases were missed.

Professor Deeks said on Twitter: ‘This test is not fit for purpose for the Government’s plans.

‘It is totally unsafe to use these tests to decide somebody does not have Covid nor “infectious”. If it were a drug surely this would warrant an immediate withdrawal from use. 

‘Missing 30 per cent with high viral loads is not safe. 

‘PHE studies said missed <5 per cent – so this is more than six times as many. You cannot risk people with high viral loads visiting their elderly relatives.’  

The Government has hailed mass testing as one of the biggest tools for getting the country out of lockdown and lifting social distancing.

Plans were this week rolled out across the UK for care homes to use rapid tests to enable visitors to see their relatives and even to stop social distancing briefly during visits.

The UK is spending more than £1billion on rapid coronavirus swab tests to try and achieve Operation Moonshot – an ambition of testing everyone in the country at least once per week.

In a TV briefing at the end of October Prime Minister Boris Johnson said: ‘We now have the immediate prospect of using many millions of cheap, reliable and above all rapid turnaround tests.

‘Tests that you can use yourself to tell whether or not you are infectious and get the result within ten to 15 minutes.

‘And we know from trial across the country in schools and hospitals that we can use these tests not just to locate infectious people but to drive down the disease

‘And so over the next few days and weeks, we plan a steady but massive expansion in the deployment of these quick turnaround tests.’

He said they would be applied in ‘an ever-growing number of situations’ including in hospitals to testing ‘whole towns and even whole cities’.

But scientists warn the tests aren’t accurate enough for people to consider themselves Covid-free if they get a negative result.

Even Public Health England’s lab tests of a kit made by Innova – the main one used in Liverpool – found it was only 77 per cent accurate in ideal conditions.

Loughborough University’s Dr Duncan Robertson said in a series of tweets about the Liverpool report: ‘So… we have a mass testing regime that has large numbers of false negatives. The problem with this is that people may take tests, be told the test is negative, and then believe they are negative.

‘This can put vulnerable people at risk, and those in the communities in which they reside, such as residents in care homes.

‘The vital message is – if you have a negative test it does not mean you are not infectious or will not be infectious.’

MailOnline has approached the Department of Health for comment.