Swabbing phones and testing for Covid is ‘just as accurate as lateral flow tests’, research suggests

Swabbing a person’s mobile phone for Covid is just as accurate as having them take a lateral flow test, a study suggests.

University College London scientists who developed the £5-a-go method say it could remove the need for uncomfortable nasal swabs.

They found that infected patients exhaled enough of the virus onto their phone screen to give an accurate diagnosis between 81 to 100 per cent of the time.

That is about as accurate as the rapid lateral flow tests currently in mass use in Britain, which miss up to 40 per cent of asymptomatic carriers. 

But the phone-swabbing method requires samples to be analysed in a lab, in the same way that the current gold-standard PCR tests are carried out.

However, the team said they can turn around tests within six hours – compared to at least 24 hours it takes for a PCR result to come back.  

And they produce fewer false positives than the lateral flow tests as well, according to the authors of the study. 

Millions of lateral flow tests, which No10 has spent billions on, are being deployed every week in England.

Boris Johnson has put the kits at the forefront of his plans to keep the country safe when the final restrictions are lifted on July 19.

Two free tests are available to everyone in England every week and they have been deployed at schools and hospitals since early in the year.  

They will also be used at festivals, music concerts and other mass events when large gatherings are given the go ahead again this summer. 

But the tests require uncomfortable swabs in the nose and throat, which can put people off taking them at home. 

Scientists have also raised concerns about the accuracy of the rapid tests, which have been shown to miss up to four in 10 asymptomatic cases and give a false positive – when someone is wrongly told they’re infected – half of the time. 

Dr Rodrigo Young, lead author of the UCL study, told MailOnline phone testing may mean the end for using nasal swabs in schools and workplaces. 

He said: ‘Nasal swabs and laboratory testing remain the gold standard for proving you do not have Covid.

‘But this [phone] method can be used for mass testing and stopping asymptomatic transmission when people do not know they have been infected. 

‘The discovery was that there there is a strong concentration of the virus on mobiles from people touching and speaking into them — similar amounts to those found in the nose.

‘And this means we can test for Covid on people’s phones cheaply and easily. 

‘I think this is a really brilliant model because it can not only help with the current pandemic but be used to prevent pandemics in the future.’

Samples are taken directly from the phone’s surface and packaging and sent to a lab for testing.

Once there, the tests follow the same procedure as regular PCR tests to determine whether someone has contracted the virus or not.  

The Phone Screen Testing (PoST) tests are produced by startup Diagnosis Biotech, based in Chile. 

They have already been used in schools and offices in the South American country.

But Dr Young says the company is considering branching into selling kits direct to people.

He says it would not take long to produce home tests that can be sent in an envelope to labs for accurate results.

The tests could be rolled out to schools for little cost, reducing the inaccuracy of the rapid tests currently in use in the UK, he said.