THOUSANDS of Brits taking ‘at home’ coronavirus swab test kits could have wrongly had negative results, a new study suggests.
In test kits sent out to millions of Brits to see if they have the virus, they were able to take nasal samples from lower down, rather than painful and uncomfortable deep swabs.
These can be done at home without the supervision of a medical procedure, and scientists said they would be just as accurate.
But a new study from officials at the University of Utah studied the accuracy of the self-collected nasal swap.
Scientists found only 70 of 86 out of 354 people who had Covid-19 were picked up by nasal swabs, compared to the deeper ones.
The deeper swabs only picked up a maximum of 81.
However, the study has not yet been published in a medical journal or peer-reviewed. It was conducted across hospitals in Utah.
It means there is a risk of people being given false negative results, and not isolating as they should.
Up to 70 per cent of people get the virus without showing any symptoms – and people still can pass it on.
Experts said that the swabs have less contact with the tissues and are less likely to pick up the bug.
Professor Paul Hunter, an infectious disease expert at the University of East Anglia, said the study findings “certainly suggest these DIY tests are not as good and miss a proportion”.
He claimed around 10 per cent of coronavirus tests could have been missed.
But Professor Hunter told MailOnline the study does not prove the tests are useless and called for larger trials of the swabs currently being used in the UK.
He said: “This study is fairly small and it needs to be repeated using a larger number of tests, preferably in the UK, before we draw reliable conclusions.”
No singular test produced 86 results, proving that no test is able to always detect the coronavirus.
But researchers said the numbers were not statistically significant as the numbers are so small.
The researchers wrote: “Relying on anterior nasal swabs alone could have missed infection in 10 to 11 patients compared with nasopharyngeal swabs or saliva, respectively.
“Missed Covid-19 cases have major clinical implications affecting isolation decisions for symptomatic 111 patients and are a lost opportunity for contact tracing.”
The Department of Health and Social Care refuted the findings, saying the evidence shows self-tests are “just as effective”.
A spokesperson said: “International peer reviewed evidence, and real-world assessments from the Department’s testing programme, has shown that swab tests taken by non-clinically trained individuals are just as effective as those taken by clinicians.
“Instructions on how to perform these types of tests are included wherever individuals are asked to undertake self-swabbing.”