Epidemiology and pathobiology of SARS-CoV-2 (COVID-19) in comparison with SARS, MERS: An updated overview of current knowledge and future perspectives

Abstract

Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) is the causative etiology of 'Corona Virus Disease-2019' (COVID-19); formerly referred as 'novel-Coronavirus-2019'. It was originated in Wuhan city, Hubei province, China in early December 2019. The World Health Organization (WHO) declared it as 'Public Health Emergency of International Concern' due to their rapid transmission and causing public and health-care-related casualties worldwide. This review provides an updated overview of COVID-19 (SARS-CoV-2), in comparison with the etiologies of the same group viz. SARS and MERS and also its future perspectives for planning appropriate strategies for prevention, control and treatment modalities to avert similar catastrophe in near future.

Keywords: COVID-19; Epidemiology; MERS-CoV; Pathobiology; SARS-CoV; SARS-CoV-2.

Fig. 1

Classification of coronaviruses (ICTV).

Fig. 2

Schematic representation of transmission of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2).

Fig. 3

Genome and genome structures of SARS-CoV, MERS-CoV and SARS-CoV-2. The genome comprises of the 5′-untranslated region (5′-UTR), open reading frame (ORF) 1a/b (bluebox) encoding non-structural proteins (NSP) for replication, structural proteins including spike (yellow box), envelop (orange box), membrane (maroon box) and nucleocapsid proteins (purple box), accessory proteins (green boxes) such as ORF 3, 3a, 3b, 4a, 4b, 5, 6, 7a, 7b, 8, 8a, 8b and 9b and the 3′-untranslated region (3′-UTR).