Coronaviruses are a large group of viruses that cause diseases in mammals and birds. They are so-called because the virus looks like it is covered with pointed structures surrounding it like a crown.
Mammalian coronaviruses, including those that infect humans, are evolved from bat coronaviruses – bats are the natural host often harbouring viruses with no apparent symptoms.
In humans, coronaviruses cause respiratory tract infections that can be mild, such the common cold, or more serious such as Covid-19, which can be mild in some people and lethal in others.
Covid-19 can be spread through inhaling tiny respiratory droplets of virus in the air or from picking up the virus on your hands from surfaces then touching your mouth, nose or eyes. It may be carried in the saliva, blood, urine, mucous, faeces or other body fluids of an infected animal or person.