Skin swabs are “surprisingly effective” at identifying Covid-19 infection, based on recent research from the University of Surrey, offering a path to a non-invasive future for Covid-19 testing.

Surrey’s researchers used non-invasive swabs to gather sebum – an oily waxy substance produced by the body’s sebaceous glands – from 83 hospitalised patients, a few of whom were diagnosed with Covid-19. The team also collected blood and saliva samples for this comparative study.  

Covid-19 has shown us that rapid testing is important in monitoring and identifying recent illnesses. In our research, we explored the relationships between different biofluids, and what changes in a single a part of the human body can tell us in regards to the overall health of a patient.

Our results show that, while blood is probably the most accurate way of testing for this virus, skin swabs usually are not too far behind – in reality, the skin swab results were surprisingly accurate.”  

Professor Melanie Bailey, co-author of the study, University of Surrey

Covid-19 has been found to significantly change the makeup of lipids (fats and oils) of biofluids akin to blood or sebum.  

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

Matt Spick, co-author and research student on the University of Surrey, commented:  

“Our research suggests that skin sebum responds to changes to the immune system in Covid-19 patients. Actually, we imagine that illness can alter the body’s natural balance across the entire range of biological systems, including skin, digestive health and others. This will help us discover and understand illness higher by providing a whole-body atlas of a disease.”  

Professor Debra Skene, co-author and Section Lead of Chronobiology on the University of Surrey, said:

“The work we reveal on this study that profiles metabolites in three different biofluids (serum, saliva and sebum) offers promise in distinguishing people positive for Covid-19 from people negative for Covid-19. The promise of a non-invasive test for Covid-19 is a reason for much of society to rejoice.”