Industrial Automation Magazine India

Fighting the COVID-19 fire with molecular diagnostics

Published on : Monday 04-05-2020

Fighting the COVID-19 fire with molecular diagnostics innovations, technologies benchmarked in the new report from IDTechEx COVID-19 Diagnostics.

Boston, April 2020 – In their brand new report ‘COVID-19 Diagnostics’, global market research firm IDTechEx benchmarked more than 100 commercial devices across various technologies, providing a deep insight into the technology trends and biotech innovations surrounding the COVID-19 global response. “You cannot fight a fire blindfolded. And we cannot stop this pandemic if we don't know who is infected. We have a simple message for all countries: test, test, test. Test every suspected case,” says Dr Tedros Adhanom Ghebreyesus, Director-General, World Health Organization (WHO). Viruses were once known as "contagious living fluids", strange infectious substances capable of slipping through the finest of filters unnoticed. SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic is indeed slipping through every layer of society, leaving behind severe public health and economic crises. Unlike in the influenza pandemic in 1918, today we are better equipped to identify the elusive bug.

Since the full genome sequencing of the SARS-CoV-2, many national laboratories have identified the regions of the genome amenable for genetic testing. The golden standard adopted by national laboratories around the world following the WHO protocol to detect the virus in individuals, is based on detecting genetic material specific to SARS-CoV-2 viruses in a person's nasopharyngeal secretions. The main tool for such genetic tests is the Reverse Transcription Polymerase Chain Reaction (RT-PCR). Primer strands that hybridise specifically to the SARS-CoV-2 genome, together with fluorescent probes, help amplify and detect the viral load present in a patient. RT-PCR, normally performed in a real-time quantitative qRT-PCR machine for live fluorescent read-out, constitutes the core element of the testing effort being deployed at the moment across the globe. Clinical laboratories with the necessary equipment and technical know-how to perform RT-PCR are leading this diagnosis effort.

However, not all countries are prepared, neither logistically or with enough equipment and capacity. An important bottleneck is the short supply of certain ancillary reagents, such as RNA extraction kits. The shortage of such supplies and long processing time, has led to many laboratories to try to circumvent some steps in the protocol and to come up with new approaches to reach the testing targets that have been set by policymakers and healthcare officials.

Apart from the time consuming thermal cycling, real-time fluorescent detection is another limitation for low-cost and portable diagnosis tools. Lateral flow assays, electrochemical detection and microbead-based arrays are integrated with PCR to detect the amplified genetic products. These hybrid systems enable faster, cheaper and palm-size devices at the expense of sensitivity and specificity. More recently, CRISPR-Cas (gene-editing tool based on speficifc gene recognition) and DNA sequencing techniques show the potential for highly sensitive and selective hybrid systems, as highlighted in "COVID-19 Diagnostics".

Resonating with the message of the WHO director general: "test, test and test", these innovations offer the tools to stop the current outbreak, as well as to prevent future outbreaks, by effective diagnostics and surveillance testing.