Experts ponder why cruise ship quarantine failed in Japan

TOKYO (AP) — As an extraordinary two-week quarantine of a cruise ship ends Wednesday in Japan, many scientists say it was a failed experiment: The ship seemed to serve as an incubator for the new virus from China instead of an isolation facility meant to prevent the worsening of an outbreak.

Since the virus was identified late last year in central China, it has sickened tens of thousands of people and killed more than 1,800.

As of Tuesday, 542 cases of the virus, known as COVID-19, have been identified among the 3,711 quarantined passengers and crew, making the ship the site of the most infections outside of China. The Diamond Princess cruise ship is also the only place where health officials have seen the disease spread easily among people beyond China.

The question now is: Why?

The Japanese government has repeatedly defended the effectiveness of the quarantine. But some experts suggest it may have been less than rigorous.

In a possible sign of lax quarantine protocols, three Japanese health officials who helped in the quarantine checks on the ship were also infected.

“There are sometimes environments in which disease can spread in a more efficient way,” said Dr. Michael Ryan, executive director of the World Health Organization's health emergencies program. Ryan said cruise ships in particular were known to occasionally accelerate spread.

“It's an unfortunate event occurring on the ship and we trust that the authorities in Japan and the governments who are taking back people will be able to follow up those individuals in the appropriate way," he said.

Japan’s health minister, Katsunobu Kato, told reporters Tuesday that all passengers who remained on the cruise ship have had samples taken and that those who tested negative would start getting off the vessel...