Greece had initially conducted random testing of incoming travellers according to ‘green’ and ‘red’ countries, however will now revert to targeted testing.

Travellers will now receive barcodes after filling out a Passenger Locator Form. An algorithm will calculate the travellers most at risk of spreading a coronavirus infection.

Dimitris Paraskevis, Associate Professor of Epidemiology at EKPA and member of the Committee of Experts at the Greek Health Ministry, said the “algorithm procedure is most likely to be able to detect the majority of imported cases.”

The algorithm will use the barcode to identify passengers on international flights which need to be tested based on the information provided on the Passenger Locator Form (PLF) 48-hours prior to their departure.

The information passengers are asked to give are their country of origin and countries they have visited in the last 15 days. A barcode based on the information will be given to each passenger which Greek authorities will use when testing for COVID-19 at Greek airports.

Mr Paraskevis told SKAI TV on Sunday that passengers will be divided according to the risk assessments. “For example, if we have 1,000 tests per day at Athens international airport Eleftherios Venizelos, these 1,000 tests will be done in such a way as to maximise the ability to detect positive cases per day and per gateway,” he said.

Filling out the PLF form became mandatory on 27 June. Greece will open 27 airports from flights abroad on 1 July. The 20 major airports to be opened up will be those of Heraklion, Chania, Corfu, Rhodes and Mykonos, as well as seven smaller ones in Ioannina, Sitia, Lemnos, Kythira, Skyros, Paros and Chios.

Ports of Patras and Igoumenitsa will also open up for ferries from Italy on 1 July, while Piraeus, Rhodes, Corfu, Volos and Katakolo ports will be open for cruise ships though no trips have been planned so far.

Border crossings remain closed and negotiations are continuing.