In late December 2019, several cases of interstitial pneumonia of unknown origin were reported in Wuhan, China, and on January 9, 2020, a novel coronavirus was identified as the causative infective agent, named 2019 novel coronavirus (2019-nCoV); the disease was termed COVID-19 .1 , 2
Figure Potential reasons for the outbreak of COVID-19 in Italy and its regional differences.