Hantavirus Killed Three People on a Cruise Ship. The U.S. Isn't Part of the Investigation.

WHO is leading the investigation. The U.S. withdrew four months ago, rejected the International Health Regulations, and gutted the CDC teams that would have done this work.

• A hantavirus outbreak at sea, and the country that built WHO isn't part of the response.

• Three dead in five weeks, starting with a fever on day five.

• Hantavirus gets into the air from rodent droppings. Then it hits the lungs.

• Hantavirus doesn't spread between people, with one possible exception.

• The investigation is running. Five countries and WHO are involved.

• The agencies, the officers, and the legal frameworks that were dismantled.

• The CDC was told to focus on infectious diseases. Then it was stripped of the capacity to investigate one.

• The risk is probably low. Proving it requires the investigation the U.S. can't join.

A hantavirus outbreak at sea, and the country that built WHO isn't part of the response.

A cruise ship is anchored off the coast of Cape Verde with 149 people on board, three passengers dead, and a virus no one expected to find in this setting. The World Health Organization is coordinating the investigation. The United States — which helped build the WHO, funded it for decades, and had 17 of its citizens aboard — withdrew from the organization earlier this year.

The official word from the WHO’s European regional director: “low risk to the public.” No need for panic or travel restrictions.

Three dead in five weeks, starting with a fever on day five.

The MV Hondius left Ushuaia, Argentina on April 1. It sailed to Antarctica, then across the Atlantic to the British territory of Saint Helena, and is now stuck off Cape Verde. There are 149 people on board; 17 are American.

The first passenger got sick on April 6, five days into the voyage. Fever, headache, stomach symptoms. He was a 70-year-old Dutch man. He died on April 11. No lab test was performed.

His 69-year-old wife accompanied his body to Saint Helena. She got sick on the flight to Johannesburg. She collapsed at the airport and died in the emergency department on April 26. Her PCR came back positive for hantavirus.

A British passenger developed fever, shortness of breath, and pneumonia on April 24. He was evacuated to South Africa. He is in intensive care in Johannesburg with confirmed hantavirus.

A German passenger died on May 2 after a four-day illness. She progressed from fever and fatigue to death in less than a week.

Three more people on board have fever and gastrointestinal symptoms. They’re being evaluated.

Hantavirus gets into the air from rodent droppings. Then it hits the lungs.

Hantavirus is a family of viruses carried by rodents. People get infected by breathing in tiny particles from rodent urine, droppings, or saliva — usually when sweeping out a shed, opening a cabin that’s been closed up, or disturbing a nest. The virus gets into the air. You breathe it in. You may not know anything is wrong for one to five weeks.

Then it hits fast.

The disease has two forms. In Asia and Europe, it attacks the kidneys. In the Americas, it attacks the lungs and heart. The American form, hantavirus pulmonary syndrome, is the one on this ship.

It starts like the flu. Fever, muscle aches, fatigue. That lasts a few days. Then the lungs fill with fluid and blood pressure drops. Patients can go from walking around to needing a ventilator in hours. Most deaths happen in the first 24 hours after hospital admission.

The case fatality rate for hantavirus pulmonary syndrome ranges from 12% to 45%, depending on the strain. There is no antiviral drug that works. There is no vaccine approved in the Americas. The only thing that reliably saves people in the worst phase is ECMO, a machine that takes over for the heart and lungs while the body fights the virus. ECMO requires a specialized team at a major hospital.

Since tracking began in 1993, the U.S. has recorded 890 cases. About 30 per year. Roughly 36% die.

Hantavirus doesn't spread between people, with one possible exception.

Hantavirus does not normally spread between people. You get it from rodents. That’s been the rule for every known strain — except one.

Andes virus, first identified in Argentina in 1995, is the only hantavirus with documented person-to-person transmission. The ship departed from Argentina.

The evidence for person-to-person spread is contested but real. In 1996 in El Bolsón, Argentina, close contacts of infected patients got sick 19 to 40 days later — the first genetic evidence of human-to-human spread. In 2014, full viral sequencing confirmed it in three cases. From November 2018 through February 2019, a person-to-person outbreak in Epuyén, Chubut Province, Argentina, caused 34 infections and 11 deaths — the largest documented cluster. The researchers identified "super-spreaders." Sexual partners of infected people had a 17.6% secondary attack rate, compared to 1.2% for other household contacts.

A 2021 review in the Journal of Infectious Diseases called the evidence “weak” and “limited to some parts of Argentina and Chile.” The reviewers couldn’t rule out that people in those clusters were just exposed to the same rodent source.

If there are no rodents on the ship and if the virus spreads among passengers anyway, that would suggest that the infection can be transmitted from person to person. Argentina’s Tierra del Fuego province, where Ushuaia sits, has never recorded a hantavirus case. If the exposure didn’t happen in port, it happened on the ship. And if it happened on the ship without a rodent source, it happened between people.

But answering that question requires investigation. The kind that involves trapping rodents on the ship, swabbing surfaces, sequencing the virus, testing all 149 passengers for antibodies, and mapping who got sick when.

The investigation is running. Five countries and WHO are involved.

Here is what is currently happening. South Africa’s National Institute for Communicable Diseases is running sequencing and metagenomics on the confirmed cases. Additional samples were sent to the Institut Pasteur in Dakar, Senegal. WHO activated its International Health Regulations notification, the system that notifies every member country’s health ministry in real time. Argentina shared the passenger and crew lists with each person’s home country through their IHR focal points. Spain has agreed to receive the ship in the Canary Islands for a full investigation and disinfection.

The system is working. Multiple countries, multiple labs, simultaneous action.

But the United States is not part of it.

The agencies, the officers, and the legal frameworks that were dismantled.

In January 2025, the administration signed an executive order withdrawing from WHO. The withdrawal took effect January 22, 2026. The U.S. also rejected the amended International Health Regulations, the legal framework that governs exactly this kind of cross-border outbreak investigation. U.S. personnel were recalled from WHO offices worldwide. CDC employees were barred from co-authoring papers with WHO staff.

Without WHO membership, the U.S. no longer has access to WHO’s surveillance databases or its working groups.

That’s the international side. Domestically, it’s worse.

By the end of 2025, between a quarter and a third of CDC employees had been fired, roughly 4,300 people.

In February 2025, the administration terminated approximately 1,300 CDC employees, including all 50 first-year Epidemic Intelligence Service officers, the disease detectives whose entire job is to investigate outbreaks like this one.

The EIS has been called the “crown jewel“ of American public health. Its officers are trained specifically to go where disease is happening and figure out why. Some of those firings were later rescinded, then another wave hit in October, cutting 40 more second-year EIS officers and 30 program coordinators. Some of those were also rescinded. The pattern was: fire, partially reinstate, fire again. Institutional memory and knowledge has been lost in the process.

The CDC’s Vessel Sanitation Program, the unit specifically responsible for cruise ship health, lost all of its full-time civilian employees. Twelve U.S. Public Health Service officers now handle all cruise ship inspections at U.S. ports. Down from 24.

Three of the CDC’s 20 port health stations have no staff at all. Half have no officer in charge.

The HHS Office of Infectious Disease and HIV Policy was eliminated.

The Morbidity and Mortality Weekly Report, CDC’s flagship scientific publication, the journal that publishes outbreak findings, had its entire staff fired. Some were later reinstated.

The CDC was told to focus on infectious diseases. Then it was stripped of the capacity to investigate one.

HHS Secretary Robert F. Kennedy Jr. said during his confirmation hearing that he wanted to “give infectious disease a break“ because it had been NIH’s “principal preoccupation.” He announced a reorganization to refocus CDC on “its original mission of infectious disease.”

Then he fired the disease detectives. Gutted the cruise ship inspectors. Withdrew from WHO. Rejected the International Health Regulations. Eliminated the Office of Infectious Disease and HIV Policy.

The agency was told to focus on infectious diseases and simultaneously stripped of the people, the international partnerships, and the legal frameworks required to investigate one.

The risk is probably low. Proving it requires the investigation the U.S. can't join.

The hantavirus on the MV Hondius likely won’t become a pandemic. The WHO assessment is probably correct. Hantavirus is hard to catch. Even the Andes virus strain, under the worst interpretation of the evidence, spreads only through close, prolonged contact — mostly intimate partners. It does not spread through casual exposure the way flu or COVID does.

But “likely” requires proof. And proof requires investigation.

In February 2020, when COVID appeared on the Diamond Princess cruise ship in Japan, a fully staffed CDC deployed a team, coordinated internationally through WHO, and published findings in MMWR. All 3,711 people aboard were tested. That investigation produced critical early data on asymptomatic transmission that shaped the global pandemic response.

In 2024, when Legionnaires’ disease appeared on two cruise ships, CDC’s Vessel Sanitation Program conducted epidemiologic, environmental, and laboratory investigations, identified the source (private balcony hot tubs), and notified operators through “regularly scheduled calls with industry partners.” Both cruise lines fixed the problem. Investigation to resolution.

In 2026, 17 Americans are aboard a ship with a confirmed hantavirus outbreak, and the United States has no formal role in the investigation. It left the organization coordinating the response. It rejected the legal framework governing it. It fired the people who would have done the work.

The virus on the ship will be identified. The sequencing will come back. The investigation will be led by South Africa, Senegal, the Netherlands, Spain, and the WHO. The answer will arrive.

It will just arrive without us.