Background

In late December 2019, the world came to know about an unknown threat caused by a pathogen with unidentified etiology originating from a seafood market in Wuhan in Hubei Province, China, and the Chinese Center for Disease Control and Prevention (CCDC) proclaimed it as novel coronavirus pneumonia (NCP) [1]. The virus now known as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is included in the orthocoronavirinae subfamily, which belongs to the Coronaviridae family and is genetically grouped into main genera: Alphacoronavirus(α-CoV), Betacoronavirus (β-CoV), Deltacoronavirus (δ-CoV) and Gammacoronavirus (γ-CoV) [2]. Seven species of coronavirus, including the latest being SARS-CoV-2, have been identified as pathogenic for humans [3]. To date, two severe disease outbreaks associated with severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) have occurred by coronaviruses in China (2002-03) and the Middle East (2012), respectively [4, 5]. On the other hand, four coronaviruses, namely, HCoV-229E, HCoV-NL63 of alpha-genus and HCoV-OC43, HCoV-HKU1 ofbeta genus, have been revealed to cause mild respiratory complications in humans [2]. The International Committee on Taxonomy of Viruses identified its symptomatic and biological similarity with SARS-CoV, hence renamed the virus the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), and the disease caused by this virus was renamed COVID-19 (coronavirus disease-19) by the World Health Organization (WHO). It is a positive stranded-RNA virus belonging to the sarbecovirus subgenus of the β-coronavirus, which also comprises other zoonotic viruses, such as SARS-CoV and bat SARS-like CoV [3]. Similar to other viruses, SARS-CoV-2 thrives on several intermediate and final hosts before infecting humans, which makes the prevention and treatment of viral infection more difficult. Although the virus has a lower mortality rate than SARS-CoV and MERS-CoV, it possesses high infectivity and transmissibility. A genome sequencing study of novel coronavirus showed that SARS-CoV-2 has 79.5% and 96% resemblance to SARS-CoV and SARSr-CoV-RaTG13 (bat SARS coronavirus), respectively, which implies the origin of coronavirus from a bat [6]. There have been several reports published on the discovery of a large number of SARS-related coronaviruses from bats, a natural reservoir of coronaviruses [7–9]. As of 20 July 2020, a total of 14,845,850 people have been infected, and 612,815 have died of the disease globally [10]. In Bangladesh, a total of 207,453 people have been infected by the virus and 2,668 have died of the disease as of 20 July 2020, with a mortality rate of 1.29%. This article aims to discuss the epidemiological study, genomic features, diagnosis, prevention and treatment scenario of Bangladesh.