The World Health Organization has declared the new coronavirus outbreak in China a public health emergency of international concern.
Coronaviruses are zoonotic, meaning they are transmitted between animals and people. The animal source of the new type of virus has not been identified.
There have been several epidemics stemming from animal sources in recent history.
Below, we take a look at some of the most serious outbreaks, their source, when they first emerged, and how deadly they are.