Covid-19 testing is usually quite invasive. But researchers think they may have a better alternative. (Credits: Hector Retamal/AFP via Getty Images)
Most people find Covid-19 testing — usually involving a swab in the nose and often the throat — invasive, uncomfortable and sometimes even painful.
Researchers at the University of Surrey think a much less unpleasant testing method could be effective: a simple swab of the skin.
When you wipe the skin with a cotton swab, it collects an oily, waxy substance your body produces, called sebum.
Scientists already know that Covid-19 can have a major impact on the composition of body fluids, including this waxy substance.
So the team decided to compare how accurately they could detect Covid-19 infection in sebum, blood and saliva.
For this they first recruited 83 hospital patients, 40 of whom tested positive on a PCR test. The others had Covid-19-like symptoms but had tested negative.
The team took blood, sebum and saliva samples from the patients, some of whom did not provide all three fluids.
The researchers then analyzed their samples to test how accurately they could detect the Covid-19 infection.
By measuring sensitivity on a scale of zero to 1, where one is the most accurate, they found that blood samples were the best fluid to detect the disease, with a score of 0.97.
Sebum was the second best option, with a score of 0.88. Saliva, which scored 0.8, offered the least accurate results.
The team says they are surprised by the accuracy of their sebum samples.
A simple skin swab may be the best way to test for Covid-19 (Credit: Getty)
Study co-author Professor Melanie Bailey said: ‘Our results show that while blood is the most accurate way to test for this virus, skin swabs don’t lag too far — in fact, the results from the skin swabs were surprisingly accurate.’
The researchers hope that skin swabs could one day be a standard way of testing for Covid-19.
Professor Debra Skene, co-author and chronobiology section leader at the university, said: ‘The promise of a non-invasive test for Covid-19 is a cause for much of society to rejoice.’
The team also thinks this type of research could help scientists better understand disease in general.
Co-author and research student Matt Spick said: ‘We believe that disease can alter the body’s natural balance across the range of biological systems, including the skin, digestive system and others.
“This can help us better identify and understand diseases by providing a whole-body disease atlas.”
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