Phone swabs can accurately detect COVID-19

An accurate, non-invasive, and low-cost method of testing for COVID-19 using samples taken from the screens of mobile phones has been developed by a team led by UCL researchers at Diagnosis Biotech. The study, published in eLife and led by Dr Rodrigo Young (UCL Institute of Ophthalmology), analysed swabs from smartphone screens rather than directly from people, and found that people who tested positive by the regular nasal swabbing PCRs were also positive when samples were taken from phone screens. The new method - known as Phone Screen Testing (PoST) - detected the COVID-19 virus on the phones of 81 to 100% of contagious people with a high viral load, suggesting it is as accurate as antigen lateral flow tests. Globally active screening for COVID-19 is still a priority as new variants keep emerging and the vaccination rollout is not guaranteed in many countries. However, testing is expensive and can be physically unpleasant, both of which are significant hurdles on the road to an effective test and trace system. As PoST is an environmental test, rather than a clinical test, it is both non-invasive and less expensive that a traditional nasal swabbing PCR. This means not only is it suitable for rollout in lower-income countries, but it also removes the discomfort of current COVID-19 testing options, potentially increasing take-up of regular testing among the general population.