Corona Virus: SARS, MERS and SARS-CoV-2 a Real Three Threats of 21st Century

Abstract

Since the discovery to before the start of the 21st century, it was considered that coronaviruses (CoVs) are the pathogens of great relevance in veterinary medicine but with a reduced impact on human health. But with the beginning of 21^st century CoVs emerged as the major global concern in human health with the epidemic of severe acute respiratory syndrome (SARS) in 2002-2003 and later after few years Middle East respiratory syndrome (MERS) in 2012. Moreover, one of the major outbreaks of 21^st century of CoVs took place in China in the end of December 2019 which becomes the global concern in human public health within few months. CoVs are the viruses belong to Coronaviridae family with single stranded positive sense approximately 30 kb in size RNA enveloped viruses. Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus are the medically important four genera of CoVs and it was investigated that SARS-CoV and MERS-CoV belong to the genus Betacoronavirus. Furthermore, genome sequencing and phylogenetic analysis explored that novel SARS-CoV-2 previously known as 2019-nCoV or COVID-19 also belongs to the same genus. Currently coronaviruses attracted the attention of researchers, scientists and pharmaceutical industries worldwide due to major risk for global public health, so we compiled very recent data to summarize the historical aspects, epidemiological aspects as well as progress in the management of the three major coronaviruses related diseases in humans.