Over the next five days, Japan faces the daunting task of testing thousands of passengers aboard a quarantined cruise ship, evacuating them and transporting those who test positive for the coronavirus — or who may have come in contact with someone who has — to medical facilities on shore.

With the health ministry yet to announce a plan to address these issues or to extend the quarantine, which is scheduled to end Wednesday, the task of getting everyone off the Diamond Princess by the deadline grows increasingly improbable.

The whole situation is like "a game with no end in sight," said Koji Wada, a professor of public health at the International University of Health and Welfare.