<![CDATA[Coronavirus: how Diamond Princess cruise ship became a 'super spreading' site]>

For almost a fortnight and counting, the Diamond Princess has resembled a floating hospital more than a luxury cruise liner, as 3,711 passengers and crew have remained under quarantine in Japan due to an outbreak of the deadly coronavirus on board.

The UK-flagged vessel, which set out on a 29-day voyage from Singapore to Yokohama on January 6, has been in lock-down since arriving at the Japanese city on February 3, after an elderly passenger who disembarked in Hong Kong tested positive for the virus, which causes the respiratory disease officially known as Covid-19.

Along the way, the ship had stopped at 14 ports, including Ho Chi Minh City in Vietnam, Kobe and Osaka in Japan, and Taipei in Taiwan, with repeat visits to a number of destinations, including Hong Kong.

While the exact source of the outbreak on the Diamond Princess is yet to be determined, it is suspected to be linked to a 80-year-old man from Hong Kong who had recently made a brief visit to mainland China.

The man boarded the ship on January 20 in Yokohama before disembarking five days later in Hong Kong, where he tested positive for the virus after seeking medical attention for symptoms including a cough.

Coronavirus: 44 more cases on Diamond Princess cruise ship

How many people have tested positive for the coronavirus on board?

Japanese Health Minister Katsunobu Kato announced on Thursday that 44 new cases of the virus had been detected on the Diamond Princess, including a quarantine officer who tested positive, bringing the total number of infections on board to at least 218.

The hike in infections came after officials announced 40 fresh cases on Wednesday. Authorities have so far tested 713 people on board, fewer than one-fifth of the total, but the outbreak already ranks as the largest single cluster of infections outside mainland China.

Japan has confirmed 247 cases overall since the virus was first detected in the Chinese city of Wuhan in late December.

Passengers are allowed short visits above deck for fresh air. Photo: Reuters alt=Passengers are allowed short visits above deck for fresh air. Photo: Reuters

Passengers who have not been diagnosed with the coronavirus have been asked to stay in their cabins, except for short visits above deck for fresh air, until the quarantine period ends on February 19.

Those who have tested positive have been evacuated to onshore medical facilities. Health officials announced on Thursday that they intended to move elderly people and those with pre-existing conditions off the ship in the coming days even if they tested negative.

Many of those on board have described the tedium of being confined to their cabins and anxiety about the virus spreading further, or expressed frustration at the lack of timely information about the outbreak coming from Japanese authorities.

"It's getting tougher by the day, and certainly for passengers with the inside cabins, it's not easy," said British passenger David Abel in a Facebook live-stream on Thursday.

Some passengers have praised the efforts of the crew to keep up people's spirits, including putting together videos featuring magic tricks and dance and stretching routines.

Matthew Smith, a passenger from the United States, has racked up thousands of followers on Twitter with his regular upbeat appraisals of the ship's food.

"Don't believe the honeymooners who would rather be in an American hospital," he wrote in one post last week. "You might have to drag me off the ship when the quarantine ends."

Some medical experts have questioned the wisdom of placing the passengers and crew in quarantine in the close confines of a ship, rather than removing them to dedicated facilities on the shore.

"Ideally, the crew members and the passengers should be quarantined at holiday camps," said David Shu-Cheong Hui, the director of the Stanley Ho Centre for Emerging Infections Diseases in Hong Kong. "The event on the Diamond Princess cruise would fit the description of a super spreading event."

Kumar Visvanathan, an infectious diseases expert at the University of Melbourne, said a cruise liner such as the Diamond Princess would be ill-equipped to prevent the spread of infections.

"It seems that though isolation in individual cabins is somewhat effective, the increasing numbers of symptomatic infections seems to suggest active infections even with the best precautions are occurring," Visvanathan said.

"It is clear that cruise ships and their individual cabins are not made for isolation purposes and depend heavily on individual participation in the isolation procedures, including respiratory hygiene, cough etiquette and hand hygiene," he said.

Visvanathan said, however, that gauging the correct response was difficult as authorities had to consider the welfare of both the general public and those on the ship.

"I think the way to look at it is there are two disparate concerns that need to be balanced," he said. "The first is the protection of the outside community which I think the Japanese government is taking as most important, and in this case isolation on board is the most efficient way to prevent infection of the Japanese population."

Criticism has also been levelled at authorities for not testing all of those on board from the start. After initially insisting that they did not have the resources to test everyone on board, health officials said on Thursday that they were now aiming to test 1,000 people a day.

The World Health Organisation, however, has defended Japan's handling of the situation, saying the country was ensuring those who were ill received proper treatment, the most important consideration during such an outbreak.

This article originally appeared on the South China Morning Post (SCMP).

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