Japanese health workers have screened 279 people from the ship who showed symptoms or who had come into contact with the infected man. The health ministry said on Friday that the people infected with coronavirus had been taken to hospitals across several prefectures.

The remaining passengers and crew members have not yet been tested and will remain quarantined for 12 more days. Some passengers shared concern about the virus’s spread and about the days ahead stuck in their cabins.

Masako Ishida, 61, said Friday that all passengers had been given a thermometer and instructed to report any reading over 37.5 degrees Celsius (99.5 Fahrenheit).

“We were screened on the first day by quarantine officers, but there hasn’t been anything ever since,” she said. “We’re told to report immediately when we feel we have a fever.”



Ms. Ishida, who is traveling with her husband and mother, said she was trying to remain calm. But she was also looking forward to leaving her cabin.



“Nobody gets out of their room unless they’re in a selected group who get to go out to the deck to breathe fresh air at designated times,” she said, “So I’m hoping that the infection will stop.”



Gay Courter, 75, an American, praised the crew but said she was “worried and upset” by the number of coronavirus cases onboard the ship.



“I would be happy if they come around and do tests,” she said, referring to the quarantine officers. “They only took our temperature once three days ago, and asked us to fill out a form. They did not swab anybody except for people who had temperatures.”

She also noted the potential consequences of a wider outbreak in Japan. “If people on the ship start dying, nobody’s going to come to the Olympics,” she said.