Genetics of Severe Acute Respiratory Syndrome Coronavirus-2 and Diagnosis of Coronavirus Disease-2019: An Overview

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a positive sense, single-stranded RNA virus, responsible for the 'coronavirus disease-2019' (COVID-19) pandemic. SARS-CoV-2 belongs to the sarbecovirus (lineage-B) sub-genus within the betacoronavirus genus of the coronaviridae family. SARS-CoV-2 shares similarities with SARS-CoV, which was responsible for the 2003 SARS epidemic. SARS-CoV-2 binds with great affinity to the Angiotensin Converting Enzyme-2 receptors on human cells, and its similar to 30 kilobases long RNA genome hijacks the host machinery and compromises the host immune system with the help of accessory proteins, such as non-structural proteins, resulting in a widespread infection. The spike protein is responsible for the contagious nature of SARS-CoV-2 and, together with the nucleocapsid protein, elicits the host inflammatory response. Several real-time reverse transcriptase polymerase chain reaction (rRT-PCR) tests have been developed to confirm SARS-CoV-2 infection in suspected cases of COVID-19. Furthermore, rapid tests based on SARS-CoV-2-specific antigens and antibodies have been developed to conduct epidemiological surveillance of the hotspot regions that are worst affected by the COVID-19 pandemic. Until effective measures to prevent the occurrence or spread of COVID-19 pandemic are developed, containment measures are being taken, such as isolation of confirmed COVID-19 patients, quarantine of individuals who may have come in contact with a SARS-CoV-2 infected individual, community-wide social distancing, state/nation-wide lockdown, etc. Several vaccines and drugs are being tested that could target the viral structural proteins, non-structural proteins or associated SARS-CoV-2 sub-genomic RNA regions.