Sounds like there are now cases in other areas in Italy as well according to the news.
Plus a hotel in Tenereife is in lockdown.
Re. the self isolation, I was thinking that a lot of people who are advised to self isolate I guess. WHo picks up the bill for that. If you are a salaried worker I guess its covered as sick leave, but if you are self employed?
I guess @Molgrips the idea is to self isolate for 14 days since you left the country so you are almost there already. Did you call 101?