Some of the crew aboard an Italian cruise ship docked for repairs at Nagasaki Port in southwestern Japan who have tested negative for the novel coronavirus will be sent home as early as this week, the vessel's operator said Monday.

According to Costa Cruises' Japanese office, it plans to send home members of the crew from the Philippines and Indonesia on one or multiple chartered flights and is considering using the same plane for Europeans. The crew members are from more than 30 nations, mostly in Asia.

A total of 148 crew members aboard the Costa Atlantica, docked at a plant of Mitsubishi Heavy Industries Ltd. in Nagasaki Prefecture, have tested positive for COVID-19, the respiratory illness caused by the virus.


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Of the 148 people, 140 are in their teens to 40s, according to the Nagasaki prefectural government.

"The general theory is that the chance is low for symptoms of people in their teens to 40s to become severe," Tomoe Shimada, a senior researcher at the National Institute of Infectious Diseases, said at a press conference. She has been providing advice for managing the situation on the cruise ship.

"If many of those infected aboard the ship are in that age bracket, then the number of severe cases should be small," she said.

Around 70 crew members who tested negative for the virus have been helping to provide those isolated aboard in their rooms with essential goods in a way that keeps them from having any physical contact with those infected people, Shimada said.

Still, the vessel has problems with taking care of the trash, cleaning and laundry, as there are not enough crew members for such daily duties, she said.

The prefectural government has not disclosed the details of those who have tested positive. There are no passengers aboard the ship, which has 623 crew members, including a Japanese translator.

Two of the infected crew, a male and a female both of foreign nationality, have been hospitalized at a designated medical facility in the city due to severe symptoms.

The remaining 621, including those with mild cases of COVID-19, have remained on board, with the Nagasaki government keeping watch on their condition.

The 621 crew are staying in cabins, but the living spaces of those who tested positive and negative are not strictly separated, so an infected crew member could be staying in a room next to that of an uninfected one, according to the Nagasaki government.

The ship was originally due to undergo repairs in China but Mitsubishi Shipbuilding Co., a unit of Mitsubishi Heavy Industries Ltd., eventually received the repair order due to the virus outbreak, which was first detected in the central Chinese city of Wuhan in late 2019.

A separate cruise ship, the Diamond Princess, was quarantined near Tokyo in February with some 3,700 people aboard after a passenger was found to have been infected with the virus. About 700 people from the ship later tested positive, while 13 died.