In Portugal, when the COVID-19 statistics is displayed on television, there is data titled "casos importados" - a list of countries followed by a number (not a big one, from 1 to about 20). What does this title supposed to mean? Is this a number of persons already having the virus (Portuguese or foreigners) who have entered Portugal from a respective country? Or is this a number of persons who then later have been diagnosed with COVID-19? Something else?