It will take some time before the COVID-19 pandemic is under control and we can lead a life without masks and nose sticks. Until then, it’s about vaccinating, vaccinating, vaccinating and testing, testing, testing. The latter mainly because we have to reckon with more and more new variants, of which no one can yet estimate how effective the vaccinations will be against it.
As good as a rapid antigen test
However, the tests – regardless of whether they are antigen or PCR tests – are unpleasant. And when it comes to testing large crowds, they are tedious. Researchers from University College London have now developed a new, simple test method that only requires wiping the display of the potential patient’s smartphone for the examination.
The method is called “Phone Screen Testing”, or PoST for short. In a study published in eLife The team led by the Chilean biochemist Rodrigo Young was able to show that people who tested positive with the usual PCR tests for nasal swabs were also identified as virus carriers if the samples were taken from their smartphone displays and not from their noses.
In 81 to 100 percent of the subjects with a high viral load – who are spreading the virus more and more among their fellow human beings – the detection via PoST worked and is surprisingly at least as good as the best rapid antigen tests.
Quick to implement
Since PoST is strictly speaking not a clinical but an environmental test, it is not subject to the strict regulations of the Medical Device Ordinance. In addition, it is less expensive than a PCR test using a nasal swab with comparable safety. This makes it particularly suitable for countries where regular testing is primarily a financial hurdle. PoST sampling also takes less than a minute and does not require medical personnel.
A particular charm is that the researchers were able to identify gene variants in the SARS-CoV-2-positive PoST samples that correspond to the alpha, beta and gamma variants of SARS-CoV-2. (When the study entered the final phase in Santiago de Chile in April 2021, the delta variant had not yet caught on.) This could monitor the development of virus variants in the population by collecting smartphone swabs.
Young hat in Chile das Start-up Diagnosis Biotech founded to carry out comprehensive COVID-19 screenings in companies and schools in Chile. His goal: avoid outbreaks and stabilize the ailing economy. Frequent tests among employees and school children are intended to identify asymptomatic infected people as early as possible in order to break the chains of infection. Diagnosis Biotech is now developing a device that will automatically take samples from smartphone displays for PoST tests and transmit the results directly to the tested person via SMS.
(jsc)
