Vector S01 - Ep. 4: The Cruise

Rachel:
Late April, twenty twenty-six. The South Atlantic Ocean. A Dutch expedition cruise ship called the MV Hondius, three weeks into a voyage from Argentina toward Cape Verde.

Two passengers are dead. A seventy-year-old Dutch man, on April eleventh, on board, of what looked like severe flu. His wife, on April twenty sixth, in a hospital in South Africa, after being airlifted off Saint Helena with his remains. More passengers are sick. Crew members are sick. The ship's medical officer is looking at a clinic full of the same wrong-shaped symptoms.

He picks up the satellite phone.

On May second, the United Kingdom notifies the World Health Organization of a cluster of severe respiratory illness on a ship in the Atlantic. The Netherlands sends a parallel notification through the European Early Warning and Response System.

Four days later, the World Health Organization confirms what the medic suspected. The cluster on the MV Hondius is hantavirus.

But it is not the hantavirus we have been talking about for the last three episodes.

It is something this disease has only ever done before in southern Argentina.

From Armbrust USA, this is Vector. Season one. Hantavirus. Episode four.

The Cruise.

I'm Rachel Marin. With me is Seth Avery.

Seth:
The strain on the Hondius is called Andes virus. As of mid-May, the World Health Organization is reporting eleven cases and three deaths from the outbreak. Former passengers and crew from twenty-three nationalities are being monitored or quarantined across Australia, Canada, France, Germany, the Netherlands, Saint Helena, Singapore, South Africa, Spain, Switzerland, Turkey, and the United States.

Rachel:
And here is the part that puts this in a different category from everything else we have covered. Andes virus is the only hantavirus on earth that is known to spread from person to person.

Rachel:
The MV Hondius is operated by a Dutch company called Oceanwide Expeditions. The voyage that became this outbreak is one they run every year. It is called the Atlantic Odyssey. It is about forty days. It starts in Ushuaia, at the southern tip of Argentina, and it ends in Praia, in Cape Verde, off the West African coast.

Seth:
Between the two ends, it stops at some of the most remote places on earth. Antarctica. South Georgia. The Falklands. Tristan da Cunha. Saint Helena. Ascension Island. The ship carries eighty-six passengers and sixty-one crew, from twenty-three nationalities. Most of the passengers are in their fifties and sixties, the kind of people who buy a six-week cruise to Antarctica because they want to see Antarctica. The crew is mostly Filipino.

Rachel:
The ship left Ushuaia on April first. On April sixth, a seventy-year-old Dutch man developed fever, headache, and diarrhea. The kind of symptoms a ship's medic sees a few times a week. On April eleventh, he developed respiratory distress and died on board.

Seth:
Oceanwide has been running expedition cruises for thirty years. The medical kit is good. The medical officer is a doctor. But there are no ICU-level capabilities on a ship like this. The nearest hospital is days away by sea.

Rachel:
The voyage continued. On April twenty fourth, the ship stopped at Saint Helena. The dead man's wife disembarked with his remains. Both were airlifted to a hospital in Johannesburg. She died there on April twenty sixth.

Seth:
At that point, in the public-health sense, nothing had been officially declared. Two deaths in two different countries. But the medical officer on the ship had more sick passengers in his clinic. Several crew members were down too. Within days, the ship's own doctor would be evacuated for serious illness himself.

Rachel:
That is the moment we opened on. The medic looking at a clinic of patients with the same wrong-shaped symptoms, picking up the satellite phone. Within hours, the call had escalated to the Dutch Ministry of Health.

Seth:
On May second, the United Kingdom notifies the World Health Organization. The Netherlands files a parallel notification through the European Early Warning and Response System. The international system officially activates.

Seth:
Now we have to do a little virology. Because the strain on this ship is not the strain we have been talking about.

Rachel:
There are over forty hantaviruses worldwide. The one that lives in the western United States, that killed Betsy Arakawa and the three people in Mammoth Lakes, is called Sin Nombre. It is carried by deer mice. It causes hantavirus pulmonary syndrome with a case fatality of about a third. It does not spread from person to person.

Seth:
The Andes virus is South American. It lives in three provinces of southern Argentina, Chubut, Río Negro, and Neuquén, and across the border in southern Chile. Its natural rodent host is the long-tailed pygmy rice rat. The case fatality is about forty percent, and in some southern Chilean hospitals it has approached sixty percent.

Rachel:
And in nineteen ninety six, in southern Argentina, eighteen people in and around the towns of El Bolsón, Bariloche, and Esquel came down with the same disease in a three-month window. That outbreak made medical history. Because among the eighteen was a doctor who had been treating one of the patients. There was no plausible way the doctor could have been exposed to rodents through the patient. The only explanation was that the patient had transmitted it to him.

Seth:
A few months later, an investigator working on the same outbreak traced the virus to a traveler who had passed through El Bolsón and gone back to Buenos Aires. Two of that traveler's intimate contacts in Buenos Aires developed the same disease. Neither contact had been to Patagonia. Neither had touched a rodent.

Rachel:
That is the only hantavirus in the world that does this. Person to person. Outside the natural geographic range of its rodent host.

Seth:
Researchers studying the Patagonian clusters later described some of those patients as super-spreaders. Most of them turned out to be caretakers, family members, or medical staff. The infectious period overlaps with the early flu-like window we walked through last episode. The window where nobody knows they are infectious.

Rachel:
That is the version of hantavirus that has been on the MV Hondius.

Rachel:
The Argentinian government is reconstructing the index case's itinerary. The seventy-year-old Dutch man who died on April eleventh, and his wife who died in Johannesburg, had been in Argentina before boarding the cruise.

Seth:
Argentinian investigators have suggested the man may have been exposed to rodents during a bird-watching activity in the Southern Cone before getting on the ship. The Andes virus sequenced from the cruise samples is closely related to the strain that circulates in those three Argentinian provinces.

Rachel:
After the index case, the working hypothesis is that the disease spread on the ship from person to person, through respiratory droplets in shared enclosed spaces. The samples from the eleven cases on the ship all look almost the same when you sequence them. That is the signature of one chain of spread, not eleven separate exposures.

Seth:
The risk of broad spread to the United States, as the CDC has put it, is, quote, "extremely unlikely." Andes virus does not transmit easily, even between people in close contact. You usually need to be a caretaker, a sexual partner, or a family member sharing a household. The cruise was a unique geometry. An enclosed space. A four-week voyage. A confined population.

Rachel:
But the fact that it spread at all is the part the public-health community is paying attention to.

Rachel:
The respiratory protection that filters hantavirus particles from a shared indoor space is an N95 or KN95.

Seth:
Cloth masks do not. Surgical masks do not.

Rachel:
We wear Armbrust KN95s on this show. Vector dot armbrust U S A... dot com. Thirty percent off anything Armbrust makes if you sign up for the newsletter.

Seth:
Back to the boat. And what the system did when the call came in.

Rachel:
On May seventh, a CDC team flew to the Canary Islands to meet the ship when it arrived. The ship had left Praia, Cape Verde, the day before, after Spain agreed to take it in. WHO and European technical experts coordinated with the ship's medical team. The European Centre for Disease Prevention and Control assessed the risk to the European general population as very low.

Seth:
On May tenth, the ship docked in Tenerife. On May eleventh, all one hundred and forty-seven passengers and crew disembarked. Special non-commercial flights moved them to their countries of residence or transit, with passengers tracked individually under public-health protocols.

Rachel:
The American passengers, sixteen of them, were flown to Omaha, Nebraska. To a facility called the National Quarantine Unit at the University of Nebraska Medical Center. It is the only federally funded quarantine unit in the United States. Twenty rooms, each three hundred square feet, each with negative-pressure airflow and en-suite bathrooms.

Seth:
The protocol is forty-two days. That is the maximum incubation period of Andes virus. Each person under monitoring takes their temperature twice a day, reports symptoms, and is observed by public-health staff. If they develop symptoms, they are transferred to higher-level care.

Rachel:
There is another remote moment worth pulling up. Tristan da Cunha is one of the islands the Hondius had stopped at. It is the most remote inhabited island on earth. Two hundred and twenty-one people live there. There is no airport. There is one medical clinic, with a two-person staff. After the Hondius outbreak was identified, the oxygen supplies on Tristan da Cunha approached critical levels for handling potential cases there.

Seth:
On May ninth, British paratroopers parachuted onto the island with oxygen tanks and medical equipment. That is what containment looks like when the nearest airport is fifteen hundred miles away.

Rachel:
Vector started this season asking why hantavirus is back. We have walked through three answers so far. The nineteen ninety three origin in Four Corners. The Mammoth Lakes cluster, where the disease found exposed workers in a tourist economy. The Hackman case, where it killed somebody famous and made the disease a household word.

Seth:
The Hondius is the answer that breaks the frame. Because in every previous case, hantavirus had been a disease about rodents and dust. The Andes variant turns it into a respiratory disease that can pass between people in a shared enclosed space.

Rachel:
The relief is that this version of hantavirus has been around since at least the nineteen nineties and has not become a pandemic. Andes virus has had thirty years to find a way to transmit efficiently between people, and has not. The geometry that allowed the Hondius cluster, enclosed quarters, a long voyage, a confined population, is unusual.

Seth:
The concern is that we have a sample size problem. The Hondius is the first time this strain has shown up outside South America in a setting designed to test human-to-human transmission. What the world health system did over the last three weeks, getting the ship to Tenerife, repatriating people across thirteen countries, building a forty-two-day monitoring net across the United States and Europe, was a real-time stress test of whether the public-health system can catch a new respiratory cluster before it spreads.

Rachel:
That stress test happened because the system worked. The ship's medic noticed the pattern. The Netherlands notified WHO. The CDC moved fast. UNMC took the American passengers. The system performed.

Seth:
What that performance has revealed is the pattern itself. Three independent hantavirus events in fourteen months. A small ski town in California. A celebrity death in Santa Fe. A cruise ship that found a person-to-person variant. None of them caused by the others. None of them caused by the same direct trigger. But all three happening inside the same fourteen-month window in a country that had not had a hantavirus story make national news in over a decade.

Rachel:
The internet is doing what the internet does when three events line up.

Rachel:
Next week is the synthesis episode. We sit with the conspiracy theory that has emerged online from these three events. We work through it point by point. We name what is real about it and what is not. We talk about why the climate signal that connects all three is a separate, harder, more important story.

We close the season by leading into the place this story is going next. The pharmaceutical companies working on a hantavirus vaccine. The one that is closest to the clinic. And the question of who is going to pay for it.

That is episode five.

Seth:
I'm Seth Avery. Vector publishes new podcasts each week as the story develops. Subscribe so that you don't miss important updates.

Rachel:
And I'm Rachel Marin. If you spend time in enclosed shared spaces with people you do not know, on planes or boats or anywhere else where the air recirculates, go to vector dot armbrust U S A... dot com, sign up for the newsletter, and get thirty percent off anything Armbrust makes.

Seth:
Vector is a Vector Media production for Armbrust USA. The information in this episode is journalism, not medical advice. If you think you may have been exposed to hantavirus, contact your local public health department or a medical provider. We are not a substitute for either.