The morning after Kent Frasure was originally set to disembark from the luxury vessel Diamond Princess and a tour of several countries in Southeast Asia with his wife, the 42-year-old was awoken by a loudspeaker in his suite.

It was a message from their captain. Their 15-day cruise, already delayed so passengers’ temperatures could be taken, would now be extended to feature a two-week quarantine after an 80-year-old Hong Kong man tested positive for the new, deadly coronavirus. Forced to remain in their rooms, the Oregonian couple celebrating their 11th cruise together saw their lush excursion—replete with high-end dining and carefully curated leisure activities—upended in dizzying fashion.

“[One] night we had four lobsters. If you want more steak, they bring more steak—or ice cream or pizza or whatever you want,” Frasure told The Daily Beast late Wednesday.

But by Friday morning, it wasn’t just their diet—a more modest chicken and rice, or sandwiches—that had been thrown into disarray. Fraser’s 35-year-old wife, Rebecca, was diagnosed with the virus. And she had company: More than 60 passengers on board the vessel off the coast of Japan had tested positive.

Rebecca Frasure was removed from the vessel to a hospital, though she told the Oregonian she was only suffering from a minor cough. “I feel fine, for the most part,” she said.

While her husband tested negative, Rebecca was reportedly slated to remain at a hospital for at least three days for symptom monitoring. If she gets better, Japanese health officials have said she can return back to the ship to wait out the rest of the quarantine.

Other infected passengers included 28 patients from Japan, 11 from the United States, seven from Australia, seven from Canada, three from Hong Kong, and one each from Argentina, Britain, New Zealand, Taiwan, and the Philippines.

Experts have roundly cautioned against panic, at least for Americans. But the virus was still rapidly spreading across the globe on Friday, with 31,481 confirmed cases in 25 countries, including China, where the virus originated in the port city of Wuhan, according to the World Health Organization. In that country, 637 people had succumbed to the virus as of Friday. Outside of China, one person had died of the disease in the Philippines.

“Cruise ships are of course very aware of the dangers of viral outbreaks and already take all kinds of very sensible precautions, but as we learn more we will need to change and update what it is that we do,” said Jeremy Brown, director of the Office of Emergency Care Research at the National Institutes of Health and the author of Influenza: The Hundred-Year Hunt to Cure the Deadliest Disease in History. “There is much that we simply do not yet know about how the new coronavirus is transmitted.”

Frasure said earlier this week that he and his wife knew about the international outbreak when they first boarded the Princess Cruise Lines ship on Jan. 20 in Tokyo, after flying into Japan the night before. But he wasn’t particularly concerned, at least early on in their six-stop trip, he told The Daily Beast.

“It’s kind of exploded since we've been here on the ship,” he said. “It wasn’t really that much on our minds, just because it was still confined to China at that point.”

Members of the ship’s medical staff eventually appeared in Frasure’s room to take their temperatures, he recalled. Then came the in-cabin quarantine. “I’m in a suite so at least I have a decent room,” Frasure told The Daily Beast, initially calling the quarantine “OK so far” thanks to robust free WiFi.

Coronavirus travel nightmares haven’t been confined to the Diamond Princess. The outbreak has left at least 420 other Americans stuck in a living-hell-limbo that has trapped more than 5,000 people on two vessels.

Susan Anabel, a 67-year-old from Washington, told KIRO 7 earlier this week that she was “looking for an adventure” when she booked a single, windowless stateroom on the Diamond Princess. She said passengers had also been informed the ship was running low on water and have been asked to only flush the toilet when necessary. (Princess Cruises did not respond to a request for comment for this story.)

“I signed up for an adventure, and I’m getting an adventure,” she said, as she told the news channel that she couldn’t even open her door except to receive food. “I don’t have a window and I don’t have a balcony, so it could get a little tight in here.”

Ideally, passengers on any quarantined cruise “will be monitored carefully, and if any of them do develop symptoms they will be taken straight to hospitals that are well-equipped to manage their illness, whether it is coronavirus or more likely a simple viral infection,” according to Dr. Adrian Hyzler, the chief medical officer for Healix International, which provides medical information to organizations whose clients travel internationally.

But even those processes only go so far. “The virus has spread pretty efficiently on ships, and quarantined passengers are certainly at risk of being infected,” said Eric Toner, a senior scientist with the Johns Hopkins Center for Health Security and the University’s School of Public Health.

Ultimately, he added: “It may be true that this will turn out to be about as lethal as the flu,” which the CDC estimates has resulted in between 12,000 and 61,000 U.S. deaths each year since 2010.

Although officials have said the risk of contracting coronavirus in the United States is low, Toner added, “From a public health perspective, another flu-like disease [during flu season] would overwhelm emergency departments and intensive care units and cause tens of thousands of additional deaths.”

As of Friday, Alex Azar, secretary of the Department of Health and Human Services, said the number of U.S. patients with confirmed coronavirus cases remained at 12, and only two of them were a product of person-to-person transmission inside the country, specifically in spouses of already infected patients. All other cases in the U.S. involved people who had recently traveled from the virus’s epicenter in Wuhan, China, where the State Department has sent about 17.8 tons of relief supplies this week, he noted.

“We expect to see additional cases of this novel coronavirus in the United States from returning passengers,” said Robert Redfield, director of the U.S. Centers for Disease Control and Prevention.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at the National Institute of Health, said Friday he still expected a potential vaccine to be ready for a phase one trial within two and a half months and that there had been “no glitches” so far in the process. Repeating an earlier caveat, he stressed at a Washington, D.C., press conference that, even if testing on such a potential vaccine began in the spring, it would likely be several more months before officials could deploy a working vaccine to actual patients.

Ultimately, even with a vaccine in the works, Hyzler said international authorities have made clear that “the virus is on top, and we are still in the dark when it comes to trying to battle it.”

For their part, the Frasures now find themselves more squarely in the middle of a fast-spreading global health emergency than they could possibly have imagined. On Friday, Kent Frasure said he'd even started receiving threats warning him not to return to the United States from apparently spooked Americans on Facebook.

As recently as Wednesday, Frasure had said he and his wife were still making jokes about it.

“Like, if one of us coughs, or has a sneeze, ‘Oh, I must have it.’”

—With reporting by Matt Taylor