Languages that use “ciao” or a similar version descended from Italian as a greeting or an informal goobye
Present in: Portuguese (tchau), Spanish from Argentina, Chile, Uruguay, Paraguay, Colombia, Venezuela, Panama, Costa Rica, Catalan, Sicilian, Maltese, Venetian, Lombard, Romansh, German (tschau), Swiss German, every Slavic language except Polish and Belarussian, Latvian, Lithuanian, Estonian (tsau), Greek, Albanian (qao), Romanian (ceau), Hungarian (csaó), Somali, Amharic, Tigrinya, Malaysian. The Vietnamese “chào” is not related to Italian, so it’s unmarked there.
Edit: the map only includes those languages that use ‘ciao’ as the most common informal way of greeting/goodbye, not as part of slang, argots or people who use it just to sound cool. For example, in Portuguese, Maltese or Latvian it has surpassed the older forms of saying goodbye in informal situations for all social classes.