The Diamond Princess cruise ship began its journey over a month ago from Yokohama, a city some 30 kilometers south of the capital Tokyo. It called at several ports in Japan, China, and Vietnam, and after two weeks at sea returned to Yokohama a day ahead of schedule. 

The reason for this – one of the passengers who boarded at Yokohama and got off at Hong Kong, later tested positive for COVID-19. The man had developed a cough before boarding the cruise, stayed on the ship for six days, and gotten a fever after disembarking. 

He tested positive for the novel coronavirus on February 1. Days later, the ship returned to Yokohama and was put under lockdown. Japanese Chief Cabinet Secretary Yoshihide Suga announced the cruise ship would be quarantined at sea, and said the health of passengers and crew members was "being prioritized."

All 3,700 people on board were subject to a 14-day quarantine. Testing for the virus got underway and confirmed cases were transferred to hospitals for treatment. 

But progress was slower than expected, and over the course of the quarantine, the number of cases ballooned to over 600. Last week, two elderly passengers died, prompting some to question whether the quarantine had been a good idea.

"Everyday we were hearing higher and higher numbers of people testing positive," Sarah Arana, one of the U.S. nationals evacuated from the cruise ship, told CGTN.

"Here were things happening like crew bringing food to our room – our cabins – opening the door. Later we found some of the crew tested positive. So in that respect, I didn't feel like the quarantine was working," she said. 

The quarantine period officially ended on Wednesday. Passengers were subject to tests and all disembarked over the past few days. But a skeleton crew remains on board and controversy has ensued, after over a dozen Americans tested positive after being brought home on a chartered flight. Similarly, Australia confirmed two of its nationals had tested positive and Israel has reported one other case.