JAPAN today hit back at criticism over “chaotic” quarantine measures on the coronavirus-riddled Diamond Princess cruise ship, as fears of a contagion mount with more passengers dispersing into the wider world.

The huge vessel moored in Yokohama near Tokyo is easily the biggest Covid-19 cluster outside the Chinese epicentre, with 621 positive cases confirmed among the passengers and crew.

Yesterday, 443 passengers disembarked from the ship after testing negative for the virus and not showing symptoms during a 14-day quarantine period. The complete removal of passengers is expected to last at least three days.

More passengers left the ship today, packing into yellow buses and leaving for stations and airports for home.

But, questions are increasingly being asked as to the wisdom of allowing former Diamond Princess passengers to roam freely around Japan’s notoriously crowded cities, even if they have tested negative.

“Is it really safe to get off?” said a headline in the Nikkan Sports tabloid.

The paper quoted a passenger as saying he was tested on Saturday, and left four days later.

“I thought I could be infected during the four days. I thought, is it really OK?”

The vessel was placed under quarantine on February 5 when a passenger who left in Hong Kong was found infected with the virus.

Passengers are confined to cabins except for brief trips on deck wearing masks and gloves, and they are told to keep their distance from others.

But, a specialist in infectious diseases at Kobe University rocked the boat with a video slamming “completely chaotic” quarantine procedures on board, a rare criticism from a Japanese official.

“The cruise ship was completely inadequate in terms of infection control,” said Kentaro Iwata in clips he has since deleted, saying “there is no need to discuss this further”.

The videos were viewed more than a million times in Japanese, and hundreds of thousands of times in English.

‘I was so scared’

The Health Ministry lashed out in defence, saying it has conducted “consultations on appropriate infection control (on) the ship” with experts, and taken a range of measures.

It also released a video showing passengers how to wash and disinfect their hands properly, and said there is “proper hygiene management” for medical workers entering and coming off the ship.

In addition, risky and safe areas are strictly divided, and there is a station installed for safely removing contaminated gear, said the ministry.

“We’ve been doing our best in the circumstances,” Health Minister Katsunobu Kato told MPs this morning.

“I want you to understand that not only our officials at the Health Ministry, but also, Self-Defence Forces officials and medical officials are working desperately hard.”

Iwata, who spent several hours on the ship, said: “There was no distinction between the green zone, which is free of infection, and the red zone, which is potentially contaminated by the virus.”

He said he was so concerned by what he saw on board during his visit on Tuesday that he has placed himself under a 14-day quarantine to avoid infecting his family.

“I was in Africa dealing with the Ebola outbreak. I was in other countries dealing with the cholera outbreak. I was in China in 2003 to deal with SARS… I never had a fear of getting (an) infection myself,” he said in one video.

“But on the Diamond Princess, I was so scared… because there was no way to tell where the virus is.”

Several countries have evacuated their citizens from the ship and insisted they undergo a further 14-day quarantine when they arrive on home soil.

Outside the Diamond Princess, Japan has seen 84 cases, including one death. – AFP, February 20, 2020.