We are planning to visit Rome next month and have done some extensive work. Now choosing airlines we see Turkish airlines has the best price by far Boston to Rome, but transits Istanbul, which is on Italy's E list. The regulations are confusing -- we have looked at the official government sites but there's no definition of 'transit'.
A bit clearer is the official danish site:
https://en.coronasmitte.dk/travel-rules/new-mandatory-testing-and-isolation-requirements
If, on the date of entry, you are arriving from a COVID-19 risk country, region or area, you do not need to self-isolate after entering Denmark.
This requires that during your journey, you did not stay for significant period of time in a COVID-19 high-risk country, region or area (a significant period is defined as staying overnight, going shopping, etc., in a COVID-19 high-risk country, region or area). If you stop only to refuel at a service station or are in transit at the airport of a COVID-19 high-risk country, region or area, you are still considered to be travelling from a COVID-19 risk country, region or area and therefore you do not need to self-isolate after entry.
It seems that there are several categories of countries: EU/Schengen, OECD, risk, high-risk, so a careful reading of the above
seems to say that if you travel from a risk country (USA) and merely transit at a high-risk country airport(Turkey) , you're status doesn't
change -- you are still in the 'risk' category rather than the 'high risk' cagegory.
But what of Italy?
Does anyone know?