More likely because there is a week-long winter school holiday in the latter part of February, and many people went to skiing resorts in Switzerland and Austria

More likely because there is a week-long winter school holiday in the latter part of February, and many people went to skiing resorts in Switzerland and Austria, transferring through airports in Italy. Those that did are generally young and in good health, so there hasn't been any fatalities yet. In the beginning, all cases could be traced to someone who had been travelling. Now we have internal proliferation, and the largest cities have ordered social distancing/partial lock-down (cancelling of events, closing of schools).