A study, published in JAMA Network Open, has looked at a smartphone-based Loop-Mediated Isothermal Amplification Assay (smaRT-LAMP) for detection of SARS-CoV-2 and influenza viruses.
Dr Alexander Edwards, Associate Professor in Biomedical Technology, Reading School of Pharmacy, University of Reading, said:
“One big – and very reasonable – question is why do we still have to send covid-19 swab samples to a laboratory for PCR testing? This is an especially big question given how many lateral flow tests are being run at home, showing quite how much easier it is to use a “point-of-care” rapid test than to run laboratory tests. The short answer is that it is technologically possible to detect virus genomes rapidly using portable assays, but we have so far struggled to mass-produce inexpensive clinical diagnostic nucleic acid testing products that come close to the simplicity and low cost of lateral flow tests.
“This paper adds to our confidence that we can detect important diseases like covid-19 or influenza virus infections outside the lab. This interesting report is important in showing the accuracy of a relatively simple test for virus in swabs from clinical samples. However, many other research groups have already shown that this type of technology and test simplification can work. The challenge remains how to deliver large scale product based on this type of technology, and to make simple, accessible products that people can make use of.
“Two differences between lateral flow and PCR are the way virus is detected, and the format. Firstly, PCR detects viral genomes whereas lateral flow uses antibodies to detect viral antigens. Secondly, PCR is a lab test using equipment, and the other is portable and disposable. Perhaps surprisingly, it has been technologically possible to detect viral genomes using portable devices for a while – research teams have demonstrated this long before covid-19 appeared, and there are many companies offering portable PCR machines. Many of these machines are used in hospitals – so why can’t we have them at home, in our local Pharmacy, or at our GP surgery? Scientists and engineers (including our own research group) have been researching innovative ways to shrink lab tests. Smartphones are very powerful tools to analyse biological assays such as clinical diagnostic tests, even just using their cameras without modification, because so many lab tests provide colour-based or visual results.
“So why the delay? Why aren’t all diagnostic tests operated by our smartphones, and instead are run on big machines in labs? Perhaps the biggest problem is actually mass-manufacturing clinical diagnostic test products that are robust and reliable. Researchers typically show the concept is possible, using hand-made tests, but it’s not been straightforward to take these experimental tests and mass-produce them in a factory. In a diagnostic lab, instruments are supervised and maintained, and quite complicated procedures can be operated by trained staff. The tests can be very finicky and delicate, and may not just “run themselves” without expert supervision. It turns out to be extremely expensive to simplify all these steps into something fool-proof and automatic, that “just works anywhere”.
“Even lateral flow tests are not failsafe – and they have very few steps. One small error in one of these steps can make them less accurate (e.g. wrong number of drops) but most diagnostic tests have quite a lot more steps to operate, making them unsuitable for home use.”
Prof Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, said:
“This looks promising to me, though, as a statistician, I don’t know enough about the how the system works to comment on details of the technology. But anyway I’d want to see data from more participants, and from use of the system out in the real world rather than in a research setting, to be confident of its practical usefulness. And, as the researchers point out in their research paper, this study uses participants from a hospital setting in the USA, and things could possibly turn out very differently in use in other settings in low- and middle-income countries where, they rightly say, it could be most useful.”
Dr Michael Head, Senior Research Fellow in Global Health, University of Southampton, said:
“I don’t know enough about the type of diagnostic to really comment on that. My words here are more broadly around implementation of this sort of technology in lower-income settings. This is perhaps beyond the immediacy of the research in this paper, and not intended as a criticism of the authors, more a general comment on how we in global health need to do better on ‘what happens next’.
“This is an interesting piece of research. The use of mobile technology and remote health programmes are likely to form a key part of how health systems operate in a post-pandemic environment. However, many of these approaches are still ‘the future’ rather than the here-and-now.
“As the authors rightly say in this article, their research was carried out in a high-income hospital rather than, for example, a rural community in sub-Saharan Africa.
“The technology has to be appropriate for the setting. Factors that affect the success of any implementation include for example the need for trained staff, sustainability beyond the end of any immediate project funding, acceptability by the local populations, and durability in different weather conditions such as heavy rain or extreme heat.
“Another very important aspect of any proposal coming from the global north is early and extensive engagement with the local decision-makers. We in the northern hemisphere do rather have a history of taking ‘our machine that goes bing’ to our favoured country of choice, and presenting it as a fait accompli for them to use. So, requesting input from the target populations is vital, to ensure any product has the best possible chance of success.
“As one example, our Ghana research has looked at population reporting of covid-like symptoms to a central place. The tool we used was designed for use by individuals with non-smart phones. They would dial a number, free of charge, and press ‘1 for yes’ and ‘2 for no’ in response to a short series of questions. Any phone can be used. If we had used an app for a smart phone, then much of the rural community would have been excluded. It is also a Ghana-led and owned platform, so has a better chance of acceptability and later successful implementation into public health systems.
“We have also just completed some survey research in rural Ghana, where the data was collected on tablets by community volunteers. They were trained by the Ghana Health Service on how to use the devices. The process was successful in collecting a large amount of data. This has the potential to be a sustainable approach around electronic data collection in the community.
“New mobile diagnostics are certainly exciting, but implementation in resource-poor settings will need consideration beyond for example the accuracy of the test itself.”
Refs – Ghana research of covid-like symptoms using mobile platform https://theconversation.com/how-digital-technology-helped-support-ghanas-covid-response-171060
Rural Ghana surveys, literally just completed, so nothing yet published
‘Assessment of a Smartphone-Based Loop-Mediated Isothermal Amplification Assay for Detection of SARS-CoV-2 and Influenza Viruses’ by Douglas M. Heithoff et al. will be published in JAMA Network Open at 16:00 UK time on Friday 28 January 2022, which is also when the embargo will lift.
All our previous output on this subject can be seen at this weblink:
Dr Alexander Edwards: “I am co-founder and shareholder of a small technology company that develops inexpensive tests that can be read using a smartphone; however we do not sell any covid-19 tests.”
Prof Kevin McConway: “I am a Trustee of the SMC and a member of its Advisory Committee. I am also a member of the Public Data Advisory Group, which provides expert advice to the Cabinet Office on aspects of public understanding of data during the pandemic. My quote above is in my capacity as an independent professional statistician.”
Dr Michael Head: “I have co-led projects in mobile health and digital health research in Ghana across this pandemic, references to that are above as part of the overall comment.”