O Outbreak WirePublic-Health Newsroom · Est. 2019
Special coverage ANDES-VIRUS CLUSTER · MV HONDIUS
Filed from London · Tenerife · Buenos Aires
Special coverage · Atlantic outbreak

Andes-virus cluster on the MV Hondius arrives in the Canary Islands.

A Dutch-flagged polar-expedition ship that left Ushuaia, Argentina, on 1 April reached Tenerife on the morning of 10 May with eight confirmed or suspected cases of hantavirus pulmonary syndrome on board, and three deaths. Investigators are tracing the source — and watching for further transmission off the ship.

BREAKINGAtlantic outbreak · Filed 10 May 2026

Hantavirus-stricken expedition ship docks in Tenerife after a five-week Atlantic passage; disembarkation begins under public-health protocol.

By the Outbreak Wire public-health desk · LONDON / SANTA CRUZ DE TENERIFE

The MV Hondius, a Netherlands-registered polar-expedition vessel carrying 147 passengers and crew, arrived at Granadilla harbour on the southern coast of Tenerife at approximately 05:30 local time on 10 May 2026, ending a thirty-nine-day passage that began in Ushuaia, Argentina, on 1 April. Spanish health authorities and a forward team from the European Centre for Disease Prevention and Control are leading a phased disembarkation under hospital-grade isolation protocol.

The cluster is the first Andes-virus outbreak ever documented outside South America. Andes virus, named for the mountain range where it was first identified in the 1990s, is the only hantavirus strain for which person-to-person transmission has been reliably demonstrated. The World Health Organization confirmed the strain on 6 May after laboratory work in South Africa, where one of the early cases died on arrival in Johannesburg.

As of the WHO's most recent situation report, dated 8 May, eight people on board have met the case definition — six confirmed and two suspected — and three have died. Two of the deaths occurred at sea; the third occurred in a hospital in Johannesburg. A fourth patient remains in critical condition.

Argentine investigators are focused on a possible exposure event in the days before sailing. Port-of-call records show the ship's complement made onshore stops in Ushuaia in late March, including a stop near a municipal landfill that has been the subject of separate reports of rodent activity. The reservoir species for Andes virus, the long-tailed pygmy rice rat, is endemic to that region; rodents that carry the virus have not been documented in the United States, and the U.S. Centers for Disease Control issued a Health Alert Network advisory on 8 May characterising the U.S. public-health risk as "extremely low".

The ship's itinerary

USHUAIA → ANTARCTIC PENINSULA → SOUTH GEORGIA → TRISTAN DA CUNHA → SAINT HELENA → ASCENSION → CAPE VERDE → TENERIFE

Three British, two Argentine and one German passenger are reported among the confirmed cases. Disembarkation is being handled in stages: passengers without symptoms will be moved by isolated coach to a hotel under a 21-day observation regime, the upper bound of the documented Andes-virus incubation period. Symptomatic passengers are being transferred directly to Hospital Universitario Nuestra Señora de Candelaria.

More on this story
InvestigationBuenos Aires

Argentine investigators trace exposure to a landfill stop near the port of Ushuaia.

Federal health officials are reviewing surveillance footage and rodent-survey data near the municipal solid-waste site visited by an expedition crew in the final days before sailing. Trapping and serology have been ordered on three sites in and around the city.

Read the Buenos Aires file
Public healthAtlanta

U.S. CDC opens contact-tracing channel for returning American passengers; risk called "extremely low".

Seven American passengers on the MV Hondius have already returned home. None has shown symptoms. The agency's HAN advisory directs clinicians to include hantavirus pulmonary syndrome in the differential for any returning traveller with febrile respiratory illness.

Read the Atlanta file
ContainmentTenerife

Disembarkation runs in stages. A 21-day observation window matches the upper bound of incubation.

Symptomatic passengers go directly to Hospital Nuestra Señora de Candelaria; asymptomatic passengers are placed under hotel-based observation. Crew members continue to be supported on board pending clearance. Spain has activated its national public-health command structure.

Read the Tenerife file
ScienceGeneva

Why Andes matters: it is the only hantavirus strain known to spread between people.

More than fifty named hantaviruses circulate worldwide, but Andes is the only one with reliably documented person-to-person transmission. Spread requires close, prolonged contact — household or hospital-room density — not casual exposure.

Read the science file
AnalysisPandemic risk

Is this the next COVID? Public-health virologists say no — and explain why.

The basic reproduction number for Andes virus, even in well-documented family clusters, has stayed close to one. The virus does not transmit efficiently in casual contact and there is no airborne pre-symptomatic shedding pattern. The pandemic concern is low; the individual-mortality concern is real.

Read the analysis
MaritimeAmsterdam

The operator says the vessel followed Antarctic-treaty biosecurity standard. Investigators want to know how an outbreak of this size went undetected for three weeks.

The first death occurred on 11 April. The cluster was not formally notified to the WHO until 2 May. Maritime medicine has long flagged the lag between onset of severe respiratory illness on a working ship and external public-health awareness.

Read the Amsterdam file

By the numbersU.S. cases since first identification, 1993–2023

Source: U.S. Centers for Disease Control and Prevention, Hantavirus Surveillance.

890
Total laboratory-confirmed U.S. cases, 1993–2023
35%
Case-fatality rate among U.S. HPS cases
94%
Share of U.S. cases reported west of the Mississippi
38
Median age of U.S. patients (years; range 5–88)

Background

What is hantavirus pulmonary syndrome?

Hantavirus pulmonary syndrome — HPS — is a severe respiratory illness caused by viruses in the Hantaviridae family. The viruses are carried by certain rodents and shed in their urine, droppings and saliva. People are usually infected by breathing aerosols when contaminated nesting material or droppings are disturbed, in confined indoor spaces such as cabins, sheds or barns.

The first U.S. outbreak was identified in 1993 in the Four Corners region — the meeting of Arizona, Colorado, New Mexico and Utah. The U.S. strain, Sin Nombre virus, is carried by the deer mouse (Peromyscus maniculatus) and remains the dominant strain in North America. The South-American strain at the centre of the current cluster, Andes virus, is carried by the long-tailed pygmy rice rat (Oligoryzomys longicaudatus) and circulates in Argentina, Chile and parts of Bolivia, Paraguay and southern Uruguay.

The illness typically begins with one to seven days of fever, muscle aches and gastrointestinal symptoms, then progresses rapidly to pneumonia, acute respiratory distress and shock. Treatment is supportive — early ICU care, careful fluid management and, in severe cases, extracorporeal membrane oxygenation (ECMO), which has been associated with survival rates approaching 80% in the small number of high-volume centres that have used it.

There is no licensed vaccine against the strains causing HPS in the Americas, and no specific antiviral therapy.

Q & A

Reader questions, answered

Should I cancel a planned cruise?

Public-health authorities are not recommending it. The MV Hondius cluster is a single, traceable event linked to a specific shore exposure in southern Argentina, not a generalised maritime outbreak. Travellers with itineraries that include rural Patagonia should review the standard CDC guidance on rodent exposure.

Could a returning passenger spread it on a flight or at home?

Person-to-person spread of Andes virus has only been documented in close, prolonged contact — typically household or hospital-room density. Casual contact on a flight or in a shop has not been documented to result in transmission. Returning passengers are nevertheless under structured monitoring through the incubation window.

How is it diagnosed?

Serology (IgM ELISA), RT-PCR on whole blood or serum and, increasingly, multiplex respiratory panels at major reference laboratories. The current advisory recommends repeat testing 72 hours after symptom onset if the first sample is negative and clinical suspicion remains high.

Is there a treatment?

No specific antiviral. Care is supportive: oxygen, careful fluids, vasopressors, and ECMO at high-volume centres. Early recognition is the dominant determinant of survival.

Where can I follow the official situation report?

The World Health Organization's Disease Outbreak News and the U.S. CDC's Health Alert Network are publishing updates through the cluster. National public-health agencies in Spain, the Netherlands, Argentina and South Africa are issuing parallel statements.

If you find rodent droppings indoors — how to clean them up safely.

The U.S. CDC's standing guidance on rodent cleanup is unchanged by the current outbreak and applies to any rural cabin, garage or storage space where mouse activity is suspected. The single most important rule: do not sweep and do not vacuum. Both push virus particles into the air.

1

Ventilate first

Open windows and doors and air the space for at least 30 minutes before entering. Leave the room while it ventilates.

2

Wear protection

Impermeable rubber or latex gloves and unvented goggles. For heavy infestation, a half-face air-purifying respirator with a HEPA filter (P100). A surgical mask is not adequate.

3

Wet, then wipe

Spray droppings, urine and nest material with a 1:9 bleach solution (one part household bleach, nine parts water) or any EPA-registered disinfectant. Let it soak for at least 5–15 minutes.

4

Bag and wash

Wipe up with paper towels, place in a sealed plastic bag, and dispose with regular household waste. Wash gloved hands with soap and water before removing gloves; wash hands again afterwards.

What not to do. Do not sweep, do not vacuum, and do not use a dry duster on droppings or nesting material — all three aerosolise the virus. If a mouse is found in a sealed food package, discard the package and clean the surrounding area as above.