The man (of Indian nationality) had no symptoms at the time of testing and was in quarantine before entering service. He disembarked the ship in Port Genoa Italy, taken into care by the local health authorities, then transferred to a COVID facility. Five other crew who had been in contact with him were disembarked as a preventive measure.
The cruise company implemented pre-screen measures for each of the crew members in their country of origin, including a couple of different swab tests for the evaluation of suspected coronavirus cases. Prior to embarking the crew are tested for the third time and those confirmed negative are allowed onboard and placed in a 14-day quarantine. During this period their health is monitored daily. Before the crew enter service, they are tested once again.
Diadema is Costa's second passenger liner to resume operations after Italy's lockdown. The vessel set sail from homeport Genoa on September 19, visiting only Italian ports and carrying only residents of Italy.
For more Costa Diadema accidents and incidents see at the ship's CruiseMinus page.