TABLE 1.

Chronological Summary of the Japanese Government’s Responses

Date	Quarantine Days	Virus Testing Policy	Immigration Restrictions and Disembarkation
February 1, 2020			The Diamond Princess stops at Okinawa and has completed quarantine upon entering Japan.11
February 3			The ship arrives at Yokohama. The quarantine in Okinawa has been canceled and passengers and crew members have been re-quarantined on the ship.11
February 5	Day 1	Screening for the virus is implemented in the aged or people with chronic disease, even if asymptomatic.1	A 14-day health observation period is set for all passengers and crew members; disembarkation is limited.1,50
February 9	Day 5	Japanese government begins considering the possibility of testing all passengers and crew members at the end of the 14-day health observation period.38,51
February 13	Day 9		A policy allows the aged to disembark, specifically, older people over the age of 80 years who are in cabins without windows and suffer from chronic illness.17,38
February 15	Day 11	Policy regarding the inspection of all passengers is implemented.52,53
February 19	Day 15		Disembarkation begins of passengers confirmed as not being infected.54
February 21	Day 17		Disembarkation of 970 asymptomatic passengers with negative test results is completed. Passengers should avoid outings, unless urgent, for 2 weeks and measure body temperature daily. Their health status should be checked regularly at health centers.55
February 22	Day 18	Crew members will be tested for viruses in the future.55	Approximately 1300 people, including crew members, foreigners waiting for charter aircraft, and passengers who were in close contact with or in the same room as a person who tested positive, are aboard.50 Disembarkation of crew members is undecided.18