In Brief

Coronavirus quarantine ends for some cruise ship passengers, sparking worries over virus spread

A member of the media wears a face mask while walking past the Diamond Princess cruise ship at Daikoku Pier in Yokohama, Japan, on Feb. 10, 2020.
(Image credit: Carl Court/Getty Images)

Nearly 500 passengers aboard the Diamond Princess cruise ship — where the new coronavirus is spreading — were allowed to disembark the vessel today (Feb. 19) after officials declared that those passengers had successfully completed a two-week quarantine.

However, some experts are concerned that this quarantine was not effective and that the released passengers may not be free of the virus, according to news reports.

The beleaguered ship has been under quarantine and docked in Yokohama, Japan, since Feb. 3, with some 3,700 passengers and crew on board. But during that time, 621 passengers have been infected with the new coronavirus, leading to worries that measures to prevent the spread of the virus on the ship were not adequate. 

Indeed, the U.S. Centers for Disease Control and Prevention (CDC) announced on Tuesday (Feb. 18) that all passengers and crew still on the ship would not be allowed to return to the U.S. for at least 14 days after leaving the ship. (The CDC has already evacuated several hundred American passengers from the ship, and those passengers are currently under quarantine at U.S. military bases.)

"While the [ship] quarantine potentially conferred a significant public health benefit in slowing transmission, CDC's assessment is that it may not have been sufficient to prevent transmission [of coronavirus] among individuals on the ship," the agency said in a statement. "CDC believes the rate of new infections on board … represents an ongoing risk."

What's more, a Japanese infectious-disease specialist who visited the ship has reported that measures to control viral spread on board were "completely chaotic," according to The New York Times. With regard to the passengers leaving the ship today, "I would not be surprised if they spread infections," the specialist, Dr. Kentaro Iwata, of Kobe University, told the Times.

However, Japanese officials said that they "made the maximum consideration to secure the health of passengers and crew," the Times reported.

Still, Japan's health minister, Katsunobu Kato, urged passengers leaving the ship to limit their public outings and to monitor their health in the following days, according to the Times.

More passengers are set to leave the ship in the next few days.

Originally published on Live Science. 

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Rachael Rettner

Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.