Future COVID-19 Tests Could Use Skins Swabs

Researchers in England have found that skin swabs are a "surprisingly effective" method to test for Covid-19 infection. The findings raise hopes for availability of a cheaper, less-invasive diagnostic.

"Covid-19 has shown us that rapid testing is vital in monitoring and identifying new illnesses,” says Professor Melanie Bailey, co-author of the study from the University of Surrey. “In our research, we explored the relationships between different biofluids, and what changes in one part of the human body can tell us about the overall health of a patient.  Our results show that, while blood is the most accurate way of testing for this virus, skin swabs are not too far behind—in fact, the skin swab results were surprisingly accurate."  

Covid-19 is known to significantly change the lipid composition of biofluids such as sebum, a waxy substance produced by the body’s sebaceous glands. To see if this could be leveraged for testing, Surrey's researchers used non-invasive swabs to collect sebum from 83 hospitalized patients, some of whom were diagnosed with Covid-19. The team also collected blood and saliva samples for this comparative study.  

By measuring changes in lipids and other metabolites of the samples, the research team observed that (with a 1.0 score being the most accurate and sensitive) blood samples scored 0.97. Skin swab tests scored 0.88, and finally, saliva tests scored 0.80.  

“Our research suggests that skin sebum responds to changes to the immune system in Covid-19 patients,” says Matt Spick, co-author and research student at the University of Surrey. “In fact, we believe that illness can alter the body’s natural balance across the whole range of biological systems, including skin, digestive health and others. This can help us identify and understand illness better by providing a whole-body atlas of a disease." 

Professor Debra Skene, co-author and Section Lead of Chronobiology at the University of Surrey, adds that the promise of a non-invasive test for Covid-19 “is a reason for much of society to rejoice.”

The findings were published recently in the journal Scientific Reports.