The coronavirus family of viruses is zoonotic, meaning the pathogen can spread between animals and humans.
Bats are a likely culprit for the epidemic and have been responsible for at least two past coronavirus outbreaks.
Between 2002 and 2003, bats and Asian civet cats were behind the severe acute respiratory syndrome (SARS) epidemic.
Then in 2012, the Middle East respiratory syndrome (MERS) is also believed to have originated in bats.
In the case of the novel coronavirus, officially dubbed SARS-CoV-2, the pathogen was most likely spread from bats to other wild and domesticated animals and then humans.