contact tracing app coronavirus

Covid-19 accurately detected in samples from smartphone screen swabs

Image credit: Dreamstime

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 per cent 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 than a traditional nasal-swabbing PCR. This makes it suitable for rollout in lower-income countries, as well as removing the discomfort of current Covid-19 testing options, which could potentially increase the take-up of regular testing among the general population. In addition, PoST sampling takes less than a minute and does not require medical personnel.

Dr Rodrigo Young said: “Like many, I was very worried about the economic and social impact that the pandemic would leave behind, particularly in lower-income countries. We knew that the only effective way to stop the spreading is to regularly test as many people as possible, but this was not happening because it’s too expensive and uncomfortable.

“We immediately knew this was something special, as 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.”

Diagnosis Biotech, a Chilean startup founded by UCL’s Dr Young, has been performing Covid-19 screenings in companies and schools in Chile to avoid outbreaks and maintain operational continuity, as frequent measurement of all workers or students allows the early identification of asymptomatic people and helps to control the spread of the virus.

A machine is currently under development by Diagnosis Biotech which will build on this research, safely taking a phone for PoST sampling and deliver the results directly via SMS to minimise contact. The researchers believe the PoST method could effectively help contain further Covid-19 outbreaks and identification of variants of concern in the years to come.

Trials of a separate method of detecting airborne Covid-19 particles are also now underway at Teesside International Airport, near Newcastle, UK.

Kromek – a US-based company better known for radiation detection solutions for the medical, nuclear and security sectors – has now branched out into coronavirus detection, developing a technology to trace levels of Covid-19 within 30 minutes which could be used in shops, lobbies and other busy public places. The company has already introduced its 'Biological Threat Detection Device' (BTDD) to a local school in Darlington from its UK base in Sedgefield, County Durham.

Kromek's BTDD works by drawing large volumes of air – i.e. 400 litres per minute – and analysing the biological content, which it then tests to detect the presence of coronavirus. The developers said that by sensing the virus particles before individuals show symptoms, it can reduce exposure to the disease and limit the spread of localised outbreaks.

Dr Arnab Basu, Kromek chief executive, said he was “proud” the technology was now being tested at Teesside International Airport. He said: “The device we are trialling is the only technology of its kind which can autonomously detect the presence of Covid-19 from huge areas. The technology has the capacity to deliver near-real-time monitoring of the presence and prevalence of the virus, enabling a return to normal life.”

Ben Houchen, Tees Valley mayor, said: “Kromek is a ground-breaking company that has adapted what it does best to develop this system in the face of the coronavirus pandemic. We’re delighted Teesside is not just one of the first airports, but one of the first buildings, to be trialling this new detector, which could be a real game-changer.”

Increased vigilance against the spread of coronavirus and emerging virulent mutations will be crucial in containing the worst effects of the ongoing pandemic. German Chancellor Angela Merkel warned today that Europe is “on thin ice” in the battle against Covid-19, with the highly contagious delta variant threatening to undo the good progress already made in reducing infections.

Merkel said the further response to the pandemic would be a main topic of discussion among European Union leaders at a meeting in Brussels on Thursday. While the number of Covid-19 cases in the 27-nation bloc continues to decline as vaccination rates climb, “the pandemic isn’t over, in particular in the world’s poor countries”, she said. “In particular the newly arising variants, especially now the delta variant, are a warning for us to continue to be careful.”

EU health officials have already predicted that the delta variant, first identified in India, will make up 90 per cent of all cases across the EU by the end of August, illustrating the need for as many people to be fully vaccinated as possible.

Meanwhile in the UK, holidaymakers are waiting for the latest government review of the foreign travel list, which might include more options for quarantine-free travel.

The update of the list, which determines the quarantine and testing requirements for people arriving in the UK, could see Malta and the Balearic Islands – which include Mallorca and Ibiza – added to the green list, some reports have suggested.

This follows the announcement that almost half of all adults aged 25 to 29 in England and a third of those aged 18 to 24 had now received their first dose of a coronavirus jab.

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