When Coronavirus Takes Over a Ship It’s Too Late to Batten Hatches

(Bloomberg) — For 3,700 passengers quarantined on a cruise liner off Japan, it began as a carefree voyage. For the new coronavirus, it was an opportunity to run rampant.

As the number of confirmed cases aboard the Diamond Princess nearly doubled to more than 130, health authorities evacuated infected travelers. The rest hunkered in their cabins, waiting to find out whether they’d come down with an illness that has killed more than 900 people in China and beyond. Operator Carnival Corp. stepped up efforts to disinfect the liner.

Keeping the coronavirus from spreading on land is hard enough. At sea, with thousands of passengers in close quarters on a ship with self-contained systems, it’s a whole different challenge. Every interaction with another passenger or crew member becomes a possible source of transmission. And the virus has many places to hide.

“If you’re going on a big cruise ship with 3,000 people, you’ve increased your chances of picking up the virus,” said Peter Andrew White, a professor of microbiology at University of New South Wales Sydney who has studied maritime norovirus outbreaks. “The cruise industry will need a new regimen on how to deal with this.”

The most pressing challenge is to separate the growing number of infected passengers aboard the Diamond Princess in Yokohama harbor from the apparently healthy. Japanese authorities have been taking those who are ill to hospitals onshore.

Ship Cleaning

With most passengers confined to their cabins, sanitizing the liner is more complicated. Authorities have approved Princess Cruises’ proposed methods for cleaning staterooms and providing fresh linens when guests are allowed outside for fresh air, the line’s President Jan Swartz said in a Feb. 8 YouTube video.

The trade group Cruise Lines International Association projected its members had 30 million cruise passengers last year. Passenger capacity in Asia almost tripled in the five years through 2018 to 4.26 million, although the industry cut back slightly last year. Thirty-nine companies now sail Asian waters in a total of 79 ships, according to the group.

In an emailed response to questions, the organization — whose members make up 90% of global capacity — said cruises are unique among modes of transportation in that they have on-board medical facilities. The group also noted that air travel is much more prevalent than cruise travel, with 4.5 billion people flying last year.

Still, cruise ship sanitation is of such importance that the U.S. Centers for Disease Control and Prevention has a Vessel Sanitation Program governing all boats carrying more than 13 passengers. There’s a 291-page operations manual to keep ships clean and prevent gastrointestinal illnesses.

The industry has learned from repeated outbreaks of norovirus, putting in place protocols to deal with the highly contagious gastrointestinal illness. Measures including hand sanitation stations placed throughout ships have probably kept the coronavirus from spreading even more, White said.

Onboard the Diamond Princess, Kent Frasure of Oregon said his wife tested positive for the coronavirus and remained in their room for another five to six hours until she was transported to a hospital north of Tokyo on Feb. 6. His test came back negative, and he has remained in the same room, which hasn’t been cleaned since Feb. 3.

“I wish they would at least give me Clorox wipes or something,” Frasure said.

Norovirus Outbreaks

Normally, after a norovirus outbreak, passengers would all disembark and the ship would be sanitized top to bottom, said Jean-Paul Rodrigue, a professor of transit geography at Hofstra University in New York.

“They would empty the ship and wipe the whole thing down and clean the entire ship,” said Rodrigue, who’s written about maritime pandemics. “Some even do fumigation.”

Passengers on the Diamond Princess are being quarantined for 14 days to prevent the further spread of the virus, so emptying the ship isn’t an option. Onboard, ways to lower the risk of transmission include extra cleaning and delivering meals individually to cabins, Rodrigue said.

In Hong Kong, 3,600 passengers on Sunday were allowed to leave another liner, the World Dream. The ship had been quarantined since Feb. 5 after Hong Kong authorities found passengers on an earlier trip had tested positive for coronavirus.