"A DEADLY GLOBAL VIRUS"
A DEADLY GLOBAL DISEASE Coronaviruses are a group of related viruses that cause diseases in mammals and birds . In humans, coronaviruses cause respiratory tract infections that can be mild, such as some cases of the common cold (among other possible causes, predominantly rhinoviruses ), and others that can be lethal, such as SARS , MERS , and COVID-19. Symptoms in other species vary: in chickens, they cause an upper respiratory tract disease, while in cows and pigs they cause diarrhea. There are yet to be vaccines or antiviral drugs to prevent or treat human corona virus infections. Corona-viruses constitute the subfamily Orthocoronavirinae , in the family Coronaviridae , order Nidovirales , and realm Riboviria . They are enveloped viruses with a positive-sense single-stranded RNA genome and ...