Hantavirus on a cruise ship: 7 cases, 3 deaths, and what 2026 actually tells us about the virus

On May 2, 2026, the World Health Organization was alerted to a cluster of severe respiratory cases aboard the MV Hondius, a Dutch-flagged cruise ship that had left Ushuaia, Argentina, on April 1. Three deaths, one passenger in intensive care in South Africa, several confirmed cases. On May 5, Geneva University Hospitals identified the strain: Andes hantavirus, the only hantavirus known to spread between humans. Beyond the headlines, the global picture is more complex — and more interesting — than the cruise-ship story alone suggests.

On April 1, 2026, the MV Hondius left Ushuaia, in southern Argentina. On board: 149 passengers and crew from 23 nationalities. The cruise itinerary was unusual — Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena, with Cape Verde planned as the destination.

On April 6, a passenger developed fever and headache. He died on April 11 from respiratory failure on board. On April 26, a second passenger — a close contact of the first — also died, after being evacuated to a hospital in Johannesburg. On May 2, a PCR test conducted in South Africa confirmed hantavirus infection in another passenger, then in intensive care.

On May 5, 2026, the Geneva University Hospitals (HUG), through their National Reference Centre for Emerging Viral Infections, formally identified the strain: Andes hantavirus, primarily found in South America. By May 6, the WHO and ECDC counted 7 cases among passengers, including 3 deaths, one patient in intensive care in Cape Town and another who returned to Switzerland after disembarking.

The ship, denied permission to dock at Cape Verde, was redirected toward the Canary Islands. Remaining passengers were placed in isolation on board.

The episode put hantavirus on the front page of major news outlets in early May. But to understand what is and is not significant about it, you need to step back. Hantavirus is not new. It has been quietly killing people on five continents for decades. The cruise ship is, in many ways, the least typical part of its 2026 story.

What hantavirus actually is

Hantaviruses are a family of zoonotic viruses, transmitted from animals to humans. They belong to the Hantaviridae family, order Bunyavirales. More than twenty viral species have been identified within the genus.

The main reservoir is the rodent: voles, mice, rats, field mice. In these animals, the infection is persistent but asymptomatic — a bank vole carrier can shed the virus throughout its life with no clinical sign. The virus passes from rodent to rodent via aerosols or fluids (urine, faeces, saliva). It is in those excretions that the route of human contamination lies.

Humans are infected almost exclusively through inhalation of contaminated aerosols: dust stirred up in a closed, poorly ventilated space where rodents have urinated or defecated. Bites are possible but rare. Typical exposure profiles: cleaning a loft or shed, handling firewood, agricultural or forestry work, gardening, sleeping in infested premises.

According to ECDC, smoking increases the risk of Puumala infection — the dominant strain in Europe.

The WHO distinguishes two main clinical forms by geographical zone:

FormRegionIncubationDominant symptomsCase fatality
Hemorrhagic Fever with Renal Syndrome (HFRS)Europe, Asia1 week to 2 monthsFever, headache, myalgia, thrombocytopenia, kidney involvement< 1% (Puumala) to 10–15% (Dobrava, Hantaan)
Hantavirus Pulmonary Syndrome (HPS)Americas1 to 6 weeksFebrile prodrome, rapid respiratory distress, pulmonary oedema, shock35% on average, up to 50% for some strains

This geographical boundary is not arbitrary. It tracks the distribution of reservoir rodent species. Andes virus — the strain identified on the MV Hondius — is associated with Oligoryzomys longicaudatus, present in the southern cone of Latin America. Sin Nombre virus, the dominant North American strain, is carried by the deer mouse. Puumala, the dominant European strain, is carried by the bank vole.

Aboard the ship: why Andes changes the picture

Andes hantavirus has one feature that worries health authorities more than any other strain: it is the only hantavirus for which human-to-human transmission has been documented.

The WHO, ECDC and HUG state this unanimously. Person-to-person transmission of Andes has been observed in very specific contexts: close and prolonged contact, household settings, certain healthcare environments. A few community clusters have been described in Argentina and Chile. For all other known strains — Puumala, Seoul, Dobrava, Sin Nombre — no human-to-human transmission has been established.

"Andes is the only hantavirus which can be transmitted person-to-person." — ECDC, assessment of May 6, 2026

This is precisely what explains the exceptional handling of the MV Hondius cluster. On-board quarantine, case isolation, contact tracing. Authorities are asking passengers and crew to monitor symptoms for 45 days, the maximum incubation period observed for Andes. Enhanced transmission precautions are recommended for healthcare workers caring for confirmed patients.

The WHO's Director for Epidemic and Pandemic Preparedness and Prevention, Dr. Maria Van Kerkhove, addressed the question directly at a press briefing on May 5: "We do know that some of the cases had very close contact with each other and certainly human-to-human transmission can't be ruled out, so as a precaution this is what we are assuming."

Should this be read as a global epidemic risk? No, and the WHO is explicit: "WHO currently assesses the risk to the global population from this event as low." The conditions for a community transmission chain are not present in Europe, North America or Asia, where the relevant rodent reservoirs do not exist.

A 2022 systematic review, peer-reviewed, qualifies the consensus: according to its authors, the body of available evidence does not robustly demonstrate broad human-to-human transmission of Andes outside a few discussed clusters. Scientific debate therefore remains open on the scale of this transmission, without questioning its occasional reality. As Angela Luis, a hantavirus researcher at the University of Montana, put it to American media on May 5: "My guess is we're going to learn a lot from this."

The global picture: where hantavirus actually lives

Hantavirus is not a fringe virus. It is rare per capita, but it is everywhere — and the burden is hugely uneven by region.

Asia: by far the largest burden

The vast majority of HFRS cases worldwide occur in East Asia, particularly China and South Korea. Estimates from a 2024 study cited by the WHO suggest 60,000 to 100,000 HFRS cases per year globally, with roughly half in China alone. Hantaan virus, named after the Hantan River in Korea, is the type-strain — the first hantavirus identified, in 1976, after Korean War-era outbreaks among soldiers had baffled epidemiologists for decades.

Asian incidence has declined over recent decades thanks to improved housing, rodent control, and (in China) systematic vaccination campaigns in endemic provinces. China developed and rolled out HFRS vaccines in the 1990s, which substantially reduced incidence. No equivalent vaccine is approved for use in Europe or the Americas.

The Americas: rarer but more lethal

In the Americas, hantavirus pulmonary syndrome (HPS) is rarer but far more deadly. The WHO recorded 229 cases and 59 deaths across eight countries in 2025, for a 25.7% case fatality rate.

In Argentina alone, the health ministry reported 28 hantavirus deaths nationwide in 2025. Chile, Brazil, Uruguay, Bolivia and Paraguay have endemic zones, mostly rural.

In the United States, the CDC reports 890 cumulative hantavirus disease cases since surveillance began in 1993. The geographic concentration is striking: New Mexico and Colorado have alternated between the top two positions for thirty years, each accumulating over 119 cases. Arizona has surged recently — 6 confirmed cases in 2023 and 11 in 2024 — far above its historical baseline, after a strong monsoon season in 2022–2023 drove a deer mouse population boom.

Two recent American cases drew unusual public attention:

  • In February 2025, Betsy Arakawa, wife of actor Gene Hackman, died of HPS at the couple's Santa Fe, New Mexico home. The case attracted more national media attention than any single hantavirus death since the 1993 Four Corners outbreak.
  • In 2024, three fatal HPS cases occurred in Mono County, California, including a 26-year-old hotel employee — a cluster that disturbed public health officials precisely because the victims had no occupational exposure to rural rodent populations.

Europe: variable, mostly Nordic and central

In Europe, hantavirus circulates mostly as Puumala, with smaller foci of Dobrava and Seoul. Annual cases vary dramatically. According to ECDC, the EU/EEA recorded 4,860 cases in 2021 — the peak of the past decade — followed by 1,885 in 2023, the lowest in the 2019–2023 window.

Two factors drive these swings: rodent population dynamics (themselves driven by beech mast, acorn yields, weather), and socioeconomic exposure patterns (forestry, rural housing, tourism). A study published in 2023 modeling Puumala incidence in Germany showed that a small set of meteorological variables can predict high-incidence years.

Some European hotspots:

  • Finland and Sweden consistently report some of the highest per-capita HFRS rates in Europe. Puumala is endemic, and the disease is sometimes referred to colloquially as "vole fever."
  • Croatia experienced a major Puumala outbreak in 2021 with 334 cases, linked to a strong 2020 beech mast year.
  • Germany has crossed 1,000 annual cases multiple times in recent years.
  • France recorded 320 cases in 2021, 75 in 2024, and an estimated 28 in 2025 — typical for a non-epidemic European year.

The 2023 ECDC report notes that 30 to 50% of confirmed European cases are hospitalized, but that under-diagnosis is likely substantial. A 2019–2020 seroprevalence study among forestry workers in northern France found 5% seropositivity in north-eastern regions and 4% in north-central regions — far above the official case rate.

Africa, Australia, the gaps

Hantavirus presence in Africa is poorly documented but increasing in surveillance reports. Recent serological evidence from West and Central Africa suggests circulation in rodent populations, with rare confirmed human cases. Australia remains, to date, one of the few inhabited regions with no documented hantavirus infections — likely thanks to the absence of suitable rodent reservoir species.

Symptoms: what to watch for

For the European/Asian forms (HFRS), the clinical picture often starts with a flu-like syndrome:

  • sudden fever (often above 38.5 °C / 101 °F);
  • intense headaches;
  • muscle pain (myalgia);
  • marked fatigue;
  • sometimes transient visual disturbances (blurred vision), fairly specific to Puumala.

In the days that follow, kidney involvement can develop: reduced urine output, lower back pain, raised creatinine on bloodwork, thrombocytopenia (low platelets). The kidney phase lasts a few days to a few weeks, followed by recovery.

For the American forms (HPS) — including the cruise-ship Andes strain — the picture is different and far more dangerous. After a few days of flu-like symptoms, the course turns abruptly respiratory: pulmonary oedema, acute respiratory distress, hypotension, cardiogenic shock. The transition from "feels like flu" to "respiratory failure" can take less than 48 hours.

When to consult a doctor. Persistent unexplained febrile syndrome warrants medical attention, especially if the person:

  • has handled firewood, stored produce, or cleaned a closed space in the previous two months;
  • lives or works in a known endemic region — Four Corners (USA), Patagonia (Argentina/Chile), Nordic countries, central Europe, north-east France, north-east China;
  • works in forestry, agriculture, sanitation, or wildlife services;
  • has traveled to South America in the previous 45 days, given the Andes context.

Diagnosis relies on serology (IgM/IgG) and PCR on early samples. There is no rapid bedside test.

No specific treatment — early supportive care saves lives

No antiviral has demonstrated clear efficacy against hantavirus in clinical trials. Ribavirin has been used in severe cases, but evidence remains insufficient for routine use. No vaccine is approved or marketed in Europe, the Americas, or most of Asia. China is the exception, with several inactivated vaccines used in domestic public health campaigns since the 1990s.

Care therefore relies on supportive management of vital functions:

  • fluid and electrolyte balance (carefully — overload worsens HPS);
  • dialysis or other renal support in case of acute kidney injury;
  • oxygen therapy and mechanical ventilation for pulmonary forms;
  • extracorporeal membrane oxygenation (ECMO) in the most severe HPS cases;
  • close hemodynamic monitoring.

This is why early identification matters so much. The earlier the diagnosis, the earlier intensive care can be mobilized — and that is what changes survival outcomes, not the medication administered.

Forest path covered with fallen leaves, with bare trees and light mist, creating a peaceful atmosphere.
A misty forest path covered in fallen leaves leads to a gate, suggesting a tranquil yet isolated setting.

How to protect yourself

The CDC, ECDC, WHO and PAHO all publish broadly aligned recommendations for limiting exposure. They mostly target people likely to enter spaces frequented by rodents.

Before entering an enclosed, rarely used space:

  • Ventilate thoroughly for at least 30 minutes.
  • Spray suspect surfaces, corners and droppings with a diluted bleach solution (one part household bleach to nine parts water).
  • Let it sit for at least 15 minutes.
  • Wear gloves and a respirator-grade mask (N95/FFP2 or better).

For cleaning:

  • Use a HEPA-filter vacuum or damp methods rather than a dry broom — sweeping aerosolizes the virus.
  • Avoid pressure washers for the same reason.
  • Double-bag waste and seal tightly.

For prevention at home:

  • Seal entry points for rodents — gaps under doors, holes around pipes.
  • Store food in sealed, rodent-proof containers.
  • Trash in tight-lidded containers.
  • Consult a doctor without delay if febrile symptoms follow any potential exposure.

For forestry, agricultural and sanitation workers, personal protective equipment is mandatory in regions with documented circulation: respirator, gloves, coveralls.

Protective masks displayed on a car dashboard, suggestive of ongoing health precautions.
Face masks are seen resting on the center console of a vehicle, highlighting personal protective measures amid health concerns.

Back to the ship

As of May 6, 2026, the official tally of the MV Hondius cluster stands at 7 cases and 3 deaths. One patient remains in intensive care in South Africa, two are symptomatic on board, one was diagnosed in Switzerland after disembarking.

The hypothesis retained by the WHO and Argentine authorities: a passenger likely contracted the virus before embarking, during exposure to rodents or their droppings in Patagonia or at an earlier stop. No signs of infection were apparent at departure from Ushuaia. The virus then likely spread through close contacts — Andes biology permits this — in the confined environment of an expedition cruise.

Enhanced quarantine protocols are in place. The Geneva University Hospitals' Centre for Emerging Viral Diseases is providing diagnostic support and coordinating information with the WHO and ECDC. European passengers are being followed by health authorities in their countries of return.

For the wider public — in Europe, North America, Asia — the message from the WHO and ECDC is consistent: the risk to the general population remains low. Hantavirus does not transmit through normal social interaction. The cruise-ship cluster is unusual precisely because Andes virus, a confined environment, and prolonged close contact converged.

Putting the episode in context

Hantavirus is a rare disease at global scale: 60,000 to 100,000 cases per year worldwide. For comparison, malaria kills more than 600,000 people annually, tuberculosis more than a million, seasonal influenza between 290,000 and 650,000.

Hantavirus is not a pandemic threat, and not an emerging issue. It is a stable zoonosis, with strong regional concentrations driven by rodent ecology. The MV Hondius cluster does not change that assessment. What it does is remind us of three things:

  • travel to certain regions exposes people to pathogens absent from their home countries;
  • confined environments can amplify infections that are normally poorly contagious;
  • international health coordination works — WHO alert May 2, strain identification May 5, ECDC assessment May 6.

Three structural surveillance signals do, however, warrant continued attention:

1. Geographic expansion of European hantaviruses. In France, the Puumala endemic zone has grown from 31 to 43 departments in nine years. Similar trends are documented in Germany and Belgium.

2. Urban Seoul virus circulation. A 2020–2022 study in Lyon, France, found 17.2% seroprevalence in brown rats in a major urban park. Similar urban Seoul circulation has been documented in Lyon, Manhattan, Baltimore, Marseille, and Mumbai. Human consequences remain rare, but the signal is new.

3. South American expansion. A 2025 review in Infectious Diseases & Immunity notes "an upward trend in cases" in South America and warns of "potential large-scale outbreaks." Whether the MV Hondius episode is a one-off or an early signal of broader Andes circulation is, as Dr. Luis put it, something we will likely learn more about in the coming months.

What we still don't know

Several uncertainties deserve to be named:

  • The exact origin of the index case on the MV Hondius — the epidemiological investigation is ongoing.
  • The real degree of human-to-human Andes transmission: the 2022 systematic review argues that available evidence is less robust than official communications suggest.
  • The level of under-diagnosis in non-endemic countries: forestry-worker seroprevalence in northern France (5%) and the U.S. west (1–2%) suggests circulation is broader than hospital data shows.
  • The influence of climate change on rodent population cycles and hantavirus emergence — a hypothesis taken seriously by ECDC, CDC and PAHO, but not yet quantitatively modeled at global scale.

The real question

In the end, the MV Hondius cluster is less a health crisis than a reminder: that there are still viruses we know relatively little about, whose circulation depends more on ecology and climate than on human action, and for which we have neither specific treatment nor — outside China — vaccines.

For the world's general population, hantavirus remains in May 2026 what it was in March: a rare disease, regionally concentrated, mostly affecting people in close contact with rodents. The MV Hondius episode does not change that assessment. It simply illustrates that under specific conditions — a confined ship, a contagious strain, prolonged contacts — the same virus can produce a cluster that none of its more common European or Asian forms ever would.

The best response to the cruise-ship outbreak, for most readers, is the same as it was before: ventilate before cleaning, don't dry-sweep, use bleach and a mask, and seek care promptly for unexplained fever after a likely exposure. The basics of rodent-borne disease control have not changed in thirty years. They remain the most cost-effective public health intervention available.

Main sources

This article is a general information guide and does not constitute personalized medical advice. If you experience concerning symptoms after a potential exposure, consult a healthcare professional without delay. If you are a healthcare professional, public health official, or witness to a documented exposure and would like to share an analysis, write to us at hello@kero.media.