Japan’s health minister said Saturday that 23 passengers were released from the Diamond Princess cruise ship without being tested for the new virus due to procedural mistakes, another sign of sloppiness in the quarantine of the ship, where more than 600 people were infected.
Health Minister Katsunobu Kato said the 23 were tested before the quarantine began Feb. 5, but were allowed to leave the ship on Wednesday and Thursday without being tested again. Three of them have since tested negative, and most of the others have agreed to be tested, he said.
He said officials have all tracked the 23 passengers down and asked them to self-quarantine at home for 14 days.
“We deeply regret that there was an operational error,” Kato said at a news conference. “We will examine what went wrong so we will not repeat the same mistake.”
The rest of the hundreds of Japanese passengers who returned home and foreign visitors staying in Japan all fulfilled the triple requirements — they tested negative for the virus, showed no symptoms and had been isolated for 14 days, Kato said. So far, the health ministry was not aware of anyone developing symptoms after returning home, he said.
Japan has confirmed more than 750 cases of the new virus, which first emerged in China, including 634 from the Diamond Princess, which docked and was quarantined in Yokohama, near Tokyo.
The ship initially carried about 2,600 passengers and 1,100 crew members. Most of the passengers were either taken to hospitals, disembarked or took chartered flights home. About 100 others who had infected roommates or contact with other passengers during the quarantine period were taken to a government facility to complete the 14-day quarantine.
Meanwhile, 18 Americans, six Australians and one Israeli passenger from the cruise ship have tested positive after returning home on their respective chartered flights, including some who had tested negative earlier, Kato said.
He said the results were understandable because they did not fully meet the stricter requirement for release from the ship. Some of them had close contacts with patients while on the ship and may have been tested just before getting infected. Kato, however, said Japanese officials were closely working with their respective countries’ health officials to follow up the cases.
Some experts and former passengers have criticized the quarantine, saying anti-infection measures were inadequate.