Researchers have developed a non-invasive and low-cost method that can accurately and rapidly detect Covid-19 using samples taken from the screens of smartphones. The researchers from University College London (UCL) in the UK analysed swabs from mobile screens rather than directly from people using the method known as Phone Screen Testing (PoST).
They found that people who tested positive by the regular nasal swabbing PCR test were also positive when samples were taken from smartphone screens.
The new method, described in the journal eLife on Tuesday, detected the COVID-19 virus on the phones of 81 to 100 per cent of contagious people with a high viral load, suggesting it is as accurate as antigen tests.
The researchers noted that 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, they said.
As PoST is an environmental test, rather than a clinical test, it is both non-invasive and less expensive than a traditional nasal swabbing PCR, according to the researchers.
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, they explained.
The team noted that PoST sampling takes less than a minute and does not require medical personnel, which eases mass adoption in big facilities and large-scale applications.
“Like many, I was very worried about the economic and social impact that the pandemic would leave behind, particularly in lower-income countries,” said Rodrigo Young from UCL Institute of Ophthalmology.
“PoST is a method that would not only make COVID-19 mass testing much easier but could also be used to contain outbreaks of new naturally occurring and man-made viruses, to avoid future pandemics,” Young said.
A machine is currently under development by Diagnosis Biotech, a Chilean startup founded by Young, which will build on this research, safely taking a phone for PoST sampling and deliver the results directly via SMS to minimise contact.