On January 7, 2020, the Central Epidemic Command Center (CECC) pointed out that Taiwan Centers for Disease Control (Taiwan CDC) had set up an investigation team to investigate into the Diamond Princess’ port of call at Port of Keelung and her passengers’ travel to the city on January 31. On February 6, preliminary outbreak investigation was completed, and the team got hold of information about the docking route of the cruise ship and disembarking passengers’ travel routes. The team then proceeded with contact tracing and categorization and tracking of disembarking passengers’ travel plans. CECC also obtained the list of the passengers who remained on board on that day and requested those passengers to be in home isolation and to monitor health status for 14 days.