I suspect there is some non compliance in Italy going on that we aren’t seeing. In fact quite a lot. In addition they made a tactical error, shutting down only part of the country instead of all of it at once.
It also seems scientists for some reason, and I don’t understand it, but they are saying that social distancing works better than lockdown/stringent measures to control the spread.
It seems they think if there is a an extended lock down a resurgence is a really really big possibility,
There is also something about viral load. Basically if you ingest/inhale a small amount of the virus, Ie from touching your shopping,or being near one person briefly,, it’s odds on you’ll be very mildly ill to non symptomatic, then gain immunity, where as if you ingest or inhale a lot, Ie from a number of people, or repeatedly in a short period , you’ll be very ill. Someone will explain that better than me, but it could explain why scientists orefer social distancing.
Because lock down won’t work long term or even mid term, , and if you only get it mildly because you’ve social distanced, then we all start to get immunity and less people are very ill.
I think Italy is not social distancing and lock down clearly isn’t working the way it’s intended, because the number of cases indicate that people are still spreading it.