Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): Emergence, history, basic and clinical aspects

In late December 2019, the world woke to a reality of a pandemic of Coronavirus Disease (COVID-19), elicited by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which belongs to a group of 13-coronavirus. The potential to cause life-threatening respiratory failure and rapid transmission puts COVID-19 in the list of Public Health Emergency of International Concern (PHEIC). In the last two decades, this is the 3rd deadliest Coronavirus pandemic, following SARS which lasted between 2002 and 2003 and Middle East Respiratory Syndrome (MERS) from 2012 till date. Globally and as of April 23rd 2020, COVID-19 has affected 2,544,792 individuals in over 200 countries, causing 175,694 fatalities. While the SARS-CoV-2 originated in China with 84,302 confirmed cases and 4642 deaths as at the time of writing this review, the rapid transmission of SARS-CoV-2 has resulted in exponential increase in the number of cases outside of China to about 10 times the report case and death in mainland China. SARS-CoV-2 is suspected to be zoonotic in nature as genetic studies have shown sequence similarity to viruses originating from bats. Extreme precautionary measures, such as curfew, shutting of borders and quarantining of individuals suspected to be infected have been instituted with immediate effect; however, due to individuals that are asymptomatic, uncontrolled human-to-human transmission has resulted in exponential infection rate and numerous loss of lives even with this lockdown measures. This review article summarizes the developing situation surrounding the SARS-CoV-2 pandemic with respect to its epidemiology, unique genomic structure, possible origins, transmission, pathogenesis, comparison with other deadly species of Coronaviruses (CoV) and emerging treatment strategies built on informed literature. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.