Abstract

The diagnostic tests for COVID-19 are ranged from molecular tests (detect the RNA virus) to serological tests (detect the past infection). Most of the molecular tests are being developed are based on the real- time RT-PCR assay. For conducting PCR assay the number of molecular targets has been identified within the RNA of Corona Virus; such as helicase (Hel), nucleocapsid (N), transmembrane (M), envelop (E) and envelop glycoproteins spike (S). Serological tests are useful in testing past infection in already recovered patients and the convalescent sera of patients with negative PCR findings. These tests are mostly based on the principles of immunochromatography, chemiluminescence or ELISA to detect IgG or IgG and IgM together in serum samples. Serodiagnosis is useful in testing convalescent sera of patients with negative PCR findings. However, the cross reactivity with other antibodies is a major challenge to serological tests. From the second week IgM titre increases and then gradually declines 3^rd week onwards, but IgG level remain stable around week 4.

LAMP, CRISPR and multiplex isothermal amplification followed by the microarray detection methods are being developed around the world, to increase the sensitivity and accuracy for virus detection. LAMP Assay could be a potential alternative to RT-PCR in coming future as a point-of -care device assay. DNA amplifies rapidly in isothermal conditions and this tech doesn’t need any specialized equipment. CRISPR-Cas 13 method is also administered, based on specific high-sensitivity enzymatic reporter, unlocks a SHERLOCK protocol for more accuracy and rapidity. NGS is an emerging technology, is used to construct NGS library by amplifying the full length of genes, could be used in epidemiological surveillance and phylogenetic analysis.

These emerging technologies can be implemented to provide better, rapid and accurate diagnosis. These could be used for epidemiological purpose in a wider community, without a need for sophisticated equipment and specific training.

RT- PCR assays help us to tackle this unprecedented outbreak of COVID-19 which has already impacted people’s lives and economy. The rapid tests kits are in high demand for providing services in emergency situations and on the bed side of the patients. These tools are best possible tools providing assistance in saving people’s lives right on time.

Keywords: COVID-19; SARSCoV-2; RT-PCR; IgG; IgM; ELISA; LAMP

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Citation

Citation: Anju Kaushal. “Current and Future Diagnostic Tests for COVID-19 - Challenges and Recommendations". Acta Scientific Microbiology 3.9 (2020): 103-119.

Copyright

Copyright: © 2020 Anju Kaushal. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.