- Disadvantages of swab tests forced scientists to look for alternatives
- US NIH has selected seven biomedical companies to develop simple mass screening methods
- US-based Fluidigm has developed a platform for mass testing using saliva
- Israel Defence-DRDO-CSIR collaboration is working on breath and sound-based testing
- Social engineering tests using smell, taste, walking and checking blood oxygen levels are also being experimented
Swab tests, though used in the gold standard RT-PCR diagnosis, have practical shortcomings like availability of skilled staff, quality collection kits or viral transport medium, high costs, sampling errors, besides the risk of healthcare workers getting infected with the virus. The other blood and plasma-based test platforms are also found to have accuracy issues.
Simple and fast mass screening
The US government's National Institutes of Health (NIH) is investing $248.7 million in new technologies for COVID-19 testing. Under the Rapid Acceleration of Diagnostics (RADx) initiative, it has awarded contracts to seven biomedical diagnostic companies to develop new lab-based and point-of-care tests. These seven, which were given Emergency Use Authorisation (EUA) by the US Food and Drug Authority (FDA), were chosen from over 650 applicants and 31 projects that were found successful in the first phase of trials, said the NIH.
Four of these introduce innovations in laboratory-based testing technologies, including next generation sequencing and integrated microfluidic chips, that can dramatically increase testing capacity and time for the result. This will pave way for fast, simpler and mass screening in schools, companies, malls and other social congregation areas.
The California-based Fluidigm has developed a microfluidics platform, which has the capacity to process thousands of PCR tests per day with a primary focus on saliva samples. SanDiego-based Mesa Biotech's hand held RT-PCR machine can detect viral RNA at the point of care and results are available from the removable cartridge in 30 minutes. California-based Talis Biomedical's point of care test detects SARS-CoV-2 through isothermal amplification of viral RNA and an optical detection system, returning a result in under 30 minutes.
San Diego-based Quidel's simple point of care technology to mass screen people can be used in a hospital or a pharmacy setting. Boston-based Ginkgo Bioworks and California's Helix OpCo's next-generation sequencing technologies can process thousands of individual tests at once and make results available in a day or two. Ginko is expected scale up to 50,000 tests per day by September and 100,000 per day by the end of the year.
Breath and sound to detect virus
Meanwhile, four technologies to detect the virus in 30 seconds, developed by the Israeli scientists, are being evaluated at Delhi's Dr Ram Manohar Lohia hospital. It's part of a collaboration between the Israeli Defence R&D, India's Defence Research and Development Organisation (DRDO) and the Council of Scientific and Industrial Research (CSIR).
In a first, people will have to blow into or speak in front of a breath-analyser like instrument to collect the sample. Using a technology called terahertz spectroscopy, the sample is deposited on a chip and examined to exactly detect the virus. Results are available in less than a minute. NanoScent, the Israei firm making the breath analyser test kits, says an extensive trial in Israel for the presence of live virus delivered results with 85 percent accuracy.The product could receive regulatory approval within months. The National Centre of Scientific Research in France is also conducting advanced trials of a breath-analyser machine to detect the virus.