CORONA-VIRUS DIVERSITY

Corona-virus: are members of the sub family coronavirinae in the family coronaviridae and the order Nidovirales(International Committee on Taxonomy of Viruses). This subfamily consists of four genera-Alpha-corona virus, Beta-corona virus, Gamma-coronavirus and Delta-coronavirus- on the basis of their phylogenetic relationships and genomic structures.the Alpha-coronbaviruses and Beta-corona-virus infect only mammals. Alpha-coronavirus and Beta-coronaviruses usually cause respiratory illness in humans and gastroenteritis in animals. 

                                                                                                                                                         

The two highly pathogenic viruses ,SARS-CoV and MERS-CoV, causes serve respiratory syndrome in human corona-viruses (HCoV-NL63, HCoV-2229E, HCoV-OC43 and HKU1) induce only mild upper respiratory diseases in immunocompetent hosts, although some of them can cause severe infections in infants, young children and elderly individuals. Alpha-coronaviruses and beta-coronaviruses can pose a heavy disease burden on livestock; these viruses include porcine transmissible gastroenteritis virus, porcine enteric diarrhoea viruse(PEDV) and the recently emerged swine acute diarrhoea syndrome corona-virus(SADS-CoV).                                                                         On the current latest data all human corona-virus are human originates.