History of Epizootics, Epidemics and Evolution of Coronaviruses

Abstract

Coronavirus (CoV), which causes animal diseases, has become a human health concern. Prior to 2003, CoV caused respiratory diseases and enteric disorders, but after 2003, CoV caused three acute respiratory syndromes, resulting in significant human deaths. Since then, research on CoV has multiplied, leading to a deeper knowledge of the species. It is in this context that this article reviews the history, the biological aspect, the evolution and the crossing of the CoV species barrier. This review shows that CoVs are formed by a large genome (27 to 33 kb) and by structural proteins (spike S, hemagglutinin esterase HE and membran protein M). Various coronaviruses have been described in a wide range of species including chickens (<i>IBV-CoV</i>), pigs (<i>PHE-CoV, PED-CoV, TGE-CoV PR-CoV, PD-CoV, SADS-CoV</i>), cattle (<i>BCoV</i>), cats (<i>FCoV</i>), dogs (<i>CCoV</i>), and humans (<i>HCoV-229E, HCoV-OC43, HCoV-NL63, HCoV-HKU1, SARS-CoV, MERS-CoV</i>, and <i>SARS-CoV2</i>). Birds and bats are the main reservoirs of CoVs, but due to the low fidelity of the replication complex, CoVs have the ability to adapt to various species. Due to the crossing of the species barrier, CoVs have a wide host range resulting in the emergence of various strains worldwide. This information can help researchers develop intervention strategies to prevent the re-emergence of CoVs in the future.