Some crew members aboard the Diamond Princess, a cruise ship that was quarantined in Yokohama port due to the outbreak of the new coronavirus, disembarked Thursday, the government said.

The disembarkation of the around 240 crew members on the ship, including many foreign nationals, is expected to last several days, according to the health ministry. On Thursday, 91 of the crew as well as the last passenger left the ship.

They will stay at the National Tax College in Wako, Saitama Prefecture, for further monitoring by doctors, and can leave the facility if they test negative for the virus, the ministry said.

Meanwhile, the number of confirmed COVID-19 virus patients in Japan excluding those related to the Diamond Princess increased to 192 as of Thursday evening. A male patient in his 80s who was confirmed to be infected on Feb. 22, died the same day, bringing the domestic death toll to four.

More than 700 passengers and crew members of the Diamond Princess have been infected and four of them had died as of Thursday.

The cruise ship was carrying 3,700 passengers and crew from 56 countries and regions when it arrived in Yokohama this month. Most of the passengers disembarked last week and some crew members left Japan with the help of their governments.

Meanwhile a woman working as a guide on a tour bus in Japan has tested positive for the coronavirus for a second time, the Osaka Prefectural Government said Wednesday, the first known person in the country to do so amid growing concerns about the spread of the infection.

The woman, a resident of Osaka, tested positive on Wednesday after developing a sore throat and chest pains, the prefectural government said in a statement, describing her as being in her forties. She first tested positive in late January and was discharged from hospital after recovering on Feb. 1, according to the statement.

Though a first known case for Japan, second positive tests have been reported in China, where the disease originated late last year. The outbreak has spread rapidly and widely, infecting about 80,000 people globally and killing nearly 2,800, the vast majority in mainland China.

Health minister Katsunobu Kato said in the Diet that the central government would need to review patient lists and keep tabs on the condition of those previously discharged, as health experts analyzed the implications of testing positive for the virus after what was initially determined to be a recovery.

“Once you have the infection, it could remain dormant and with minimal symptoms, and then you can get an exacerbation if it finds its way into the lungs,” said Philip Tierno Jr., Professor of Microbiology and Pathology at NYU School of Medicine.

Tierno said much remains unknown about the virus. “I’m not certain that this is not biphasic, like anthrax,” he said, meaning the disease appears to go away before recurring.

Asked to comment on prospects for the Olympic Games going ahead in Tokyo this summer, Tierno said, “The Olympics should be postponed if this continues … There are many people who don’t understand how easy it is to spread this infection from one person to another.”

As part of the attempts to contain the outbreak, Tokyo Olympics officials are considering scaling down the torch relay, Tokyo 2020 CEO Toshiro Muto said on Wednesday.

The government is also considering scaling back this year’s March 11 memorial ceremony for victims of 2011’s massive earthquake and tsunami, Chief Cabinet Secretary Yoshihide Suga told reporters Thursday.

Meanwhile, a major bank reported an employee had tested positive for coronavirus. MUFG Bank, part of Mitsubishi UFJ Financial Group Inc, the country’s largest lender by assets, said a staff member at a branch in central Aichi Prefecture, had been confirmed to have the virus on Wednesday.

RELATED PHOTOS Workers walk past the coronavirus-hit Diamond Princess cruise ship at the port of Yokohama on Friday. | REUTERS

Crew members are seen aboard the Diamond Princess cruise ship at the Daikoku Pier Cruise Terminal in the port of Yokohama on Monday. Hundreds of crew members were to begin disembarking on Thursday. | AFP-JIJI