Michael T. Osterholm, director of the Centre for Infectious Disease Research and Policy at the University of Minnesota, described the quarantining of the Diamond Princess as “a cruel human experiment”.

“Keeping people on cruise ships is not the answer, getting them off as soon as possible is the answer,” he said. “From that standpoint, nothing we saw that happened on those cruise ships should have been unexpected.”

There have been more than 650 confirmed cases of the coronavirus among the 2,666 passengers and 1,045 crew, hailing from more than 50 countries, on board the vessel.

The number of infections on board mounted rapidly after the ship went under quarantine in Yokohama on February 5, after an elderly passenger from Hong Kong tested positive for the virus.

Eleven days before the lockdown in Yokohama, the vessel had disembarked from Hong Kong as part of a voyage between Singapore and Yokohama that took in 11 ports, including Ho Chi Minh City and Da Nang in Vietnam, Osaka and Kagoshima in Japan, and Keelung in Taiwan.

The Japanese authorities on Thursday announced the deaths of an 87-year-old man and an 84-year-old woman, both Japanese, who had been passengers on the ship, marking the first fatalities linked to the cruise. Both of the deceased reportedly suffered from pre-existing conditions.

Speaking on condition on anonymity, a Japanese health official insisted that the authorities had no choice but to quarantine the vessel due to a lack of suitable facilities on shore, but admitted they had not adequately advised those aboard about the risks of spreading the virus through everyday contact and activities.

“This must be reflected on,” the official said.

The effort to contain the spread of the virus among cruise ship passengers is complicated by the elaborate itinerary of cruise travel, which involves an extensive network of tour guides, taxi drivers and others in the hospitality industry across port cities in Asia. The challenge of containing the outbreak on board the ship has also flagged the need to closely track and monitor passengers and people with whom they have come into close contact.

“At a minimum, known potential contacts should be notified and advised to self-quarantine,” said Stanley Deresinski, an infectious disease specialist at Stanford University. “However, people have to make a living to survive and, to the extent such individuals have to work to do so, they are unlikely to adhere to such quarantine warnings.”

TRACKING TRIPS ASHORE

Questions remain about whether passengers on the two vessels, particularly the Diamond Princess, could have spread the virus further than currently known while interacting with tour guides and drivers during excursions at numerous ports across Asia before the first cases were detected.

Jean-Paul Rodrigue, professor of transport geography at Hofstra University in New York, said passengers could have infected those they interacted with during shore visits: “This includes guides, drivers, shopkeepers and restaurant operators – those groups that they could be in close personal contact with.”

Last week, a taxi driver in Naha, Okinawa, tested positive for the virus after coming into contact with passengers from the Diamond Princess during the ship’s visit to the port city on February 1.

Recovered coronavirus patients ‘may still be contagious’

At least 25 major tour companies provided packages during the ship’s visits to Osaka, Yokohama, Toba, Kagoshima and Naha.

The Japanese health official who asked not to be named said the authorities were working to check up on all tour operators and staff. This Week in Asia could not independently confirm the extent of these inquiries.

Chuang Jen-hsiang, deputy director of the Taiwan Centers for Disease Control, said officials had tracked down 212 people, including 54 tour bus and taxi drivers, who had more than 15 minutes’ contact with passengers and required them to undergo 14 days of quarantine at home. After the two-week home quarantine period, Chuang said all of them had tested negative for the virus.

Taiwan’s Health and Welfare Ministry said it had disinfected sites popular with tourists that had been visited by about 700 passengers, including the Taipei 101 Tower and the National Palace Museum. The self-ruled island has confirmed 23 cases of the virus so far.

Tourism officials said last week that 340 passengers had disembarked in Chan May and 345 in Da Nang, and all tour operators and staff who came in contact with these passengers had been identified and put into quarantine or monitored. Officials said that after close monitoring during the two-week incubation period, none of these people displayed symptoms of the virus.

Coronavirus: fears rise as Westerdam passengers return to US, Canada

The authorities in Ha Long Bay said they tested everyone who closely interacted with passengers and disinfected boats they had used following the cruise ship’s visit to the port on January 27.

Interviews with local operators, however, suggest the government’s monitoring was not as encompassing as portrayed.

A staff member at Saigon Tourist in Ho Chi Minh City, one of the country’s biggest tour companies, said 21 guides at the company who handled tours for Japanese passengers from the Diamond Princess at each of the destinations had gone to hospital of their own volition to get tested but had not been directed by, or heard from, the authorities. The staff member, who spoke anonymously over fears of professional repercussions, said all of the guides tested negative for the virus.

The owner of a small tour company in Chan May said he also was not contacted by the government after two Canadian passengers from the cruise ship took one of his tours, but neither the guests nor his staff had shown any signs of illness then or since.

CRUISING FOR A BRUISING

Tour group operators and local hospitality industry workers are not the only ones who will take a hit from the outbreak. The public health emergency also risks the profits of cruise giants like Carnival Corporation, which owns both the Diamond Princess and the Westerdam and in 2018 held the second-largest share of the global cruise market after Royal Caribbean, taking in US$4 billion in revenue. According to industry monitor Cruise Market Watch, the global cruise industry was worth more than US$45 billion in 2018, up nearly 5 per cent from the year before, with passengers from Asia tripling in the past decade, the industry’s fastest-growing segment.

The number of cruise goers originating in Asia has rapidly become one of the fastest-growing segments of the industry, according to a forthcoming study on port economics and management done by Theo Notteboom, Athanasios Pallis and Rodrigue.

Though most passengers in 2018 were from the US – with more than 12 million Americans taking cruises that year – the number of passengers coming from China has tripled in the period from 2013 to 2018 to eclipse those coming from Britain, Germany and Australia, the other major cruise-going nations.

Japan scientist stands by ‘chaotic’ criticism of cruise ship quarantine

Experts warn that the industry could take a massive hit from the uncertainty generated over the outbreak.

Candyce Stapen, family travel expert for Frommer’s Guides, said: “Some cruise lines have already cancelled voyages through March that had ports in China and other Asian countries, and large hotels could also take a hit.”

Amid concern that even people without symptoms who had tested negative for the virus could still pose an infection risk to the public, by Friday nearly more than 1,000 passengers had been allowed to disembark from the Diamond Princess, provided they had tested negative for the virus and had not shared a room with any infected person.

Japanese nationals had accounted for about half of the passengers on board, and Japan’s health ministry said that passengers would continue to be contacted to provide officials with updates on their health over the next several days. They were otherwise free to go about their lives as normal, the ministry said.

The Japanese health official who asked not to be named said Tokyo had so far declined to take drastic measures to control the virus, such as banning entry for recent travellers to China, out of consideration for relations with Beijing.

“We prioritised the economic effects of Chinese tourists visiting Japan,” the official said.

The US Centres for Disease Control and Prevention this week said it did not consider special management necessary for people exposed to asymptomatic people at risk of contracting the virus. But Deresinski at Stanford said uncertainty about whether individuals with no symptoms could still be contagious made letting passengers return home a risky move.

“Ship quarantining had the potential to protect the people on shore, but it obviously did not work on board – and then potentially failed when asymptomatically infected individuals were set free,” said Deresinski.

Similar concerns surrounded the passengers and crew of the Westerdam after an 83-year-old passenger from the US last weekend tested positive for the virus in Malaysia, though the US Centres for Disease Control and Prevention later said the woman “never had coronavirus to our knowledge”. The ship, property of the same California-based Carnival Corporation that owns the Diamond Princess, docked at Sihanoukville, Cambodia, on February 13 after spending nearly two weeks stuck at sea following its departure from Hong Kong on a two-week voyage at the start of the month.

Cambodia’s Ministry of Health said on Thursday that all 781 known passengers in the country and 747 crew members had tested negative for the virus.

Many passengers now remain stranded in the Southeast Asian country despite receiving a clean bill of health due to the difficulty of booking connecting flights to the Americas, Europe and Australia after the authorities in Thailand, Singapore, Malaysia and Taiwan announced bans on the entry of occupants from the ship.

84 more cruise passengers return to Hong Kong, blunder leaves 18 in the lurch

Gerald Carlson, a 73-year-old retiree from Chicago who was waiting for updates on travel arrangements after he and his wife were declared infection-free, said: “It’s been a real mixture of emotions: frustration, anger, but I’m thankful that we’re in the position that we are.”

At Phnom Penh’s Sokha Hotel, where hundreds of passengers have been given temporary accommodation, few guests or staff appeared to be taking precautions in response to the virus.

“No one has been wearing masks for three days, and we’ve had absolutely no problems whatsoever,” said Stephane Masse, the hotel’s general manager. “My team told the staff that if they want to wear a mask in the hotel, they have a right to wear a mask.”

TRYING TO STOP THE WIND

Although many experts continue to stress the need to fight the spread of the virus at every turn, others already see containment as being a lost cause.

Osterholm said it was now clear that the virus was transmitted in a similar way to influenza, rather than diseases such as Sars and Mers, which were successfully contained in the past, making efforts to control its spread analogous to “trying to stop the wind”.

“At this point, I think it really is a matter of reorienting what we’re doing,” he said.

“It is all about, at this point, how do we prepare our hospitals and our communities to deal with this.”

“Much of our containment activities are akin to fixing three of the five screen doors on your submarine,” added Osterholm. “I don’t think it’s really going to matter any more. This thing is out.” ■

Additional reporting by Jon Lawrence and Danielle Keeton-Olsen