Outbreak file
The 2026 MV Hondius Hantavirus Outbreak: What We Know So Far
Three deaths, seven confirmed cases, twenty-three nationalities and one quiet Antarctic itinerary. This is what the MV Hondius investigation has produced, and what it has not.
The MV Hondius set sail from Ushuaia, Argentina, on 1 April 2026. By the time the vessel docked at Granadilla Port in Tenerife on 10 May, three of the 147 people aboard had died and the World Health Organization had named the cause: Andes virus, the only strain of hantavirus known to spread from one person to another. Three days later, the first confirmed case in a person who never set foot on the ship has been identified in Tenerife.
It is the first time a recognised hantavirus cluster has been tied to international cruise travel. It is also the first time most of the world has heard of Andes virus at all. This article is a living summary: what investigators have established, what is still under inquiry, and the questions readers keep sending us.
- Pathogen
- Andes orthohantavirus (ANDV)
- Vessel
- MV Hondius, expedition cruise ship
- Departure
- Ushuaia, Argentina, 1 April 2026
- Port of arrival
- Granadilla, Tenerife, 10 May 2026
- Onboard total
- 147 people (86 passengers, 61 crew)
- Nationalities
- 23 countries represented
- Confirmed cases
- 7 (6 onboard, 1 secondary) as of 13 May
- Suspected cases
- 3, including one awaiting confirmation in Sweden
- Reported deaths
- 3
A timeline of the outbreak
- 1 April 2026 - MV Hondius departs Ushuaia for an Antarctic and South Atlantic itinerary, with planned stops at South Georgia Island, Tristan da Cunha, Saint Helena and Ascension Island.
- Late April - Crew note an unusual cluster of febrile illness; initial assumption is seasonal influenza picked up onshore in Patagonia.
- 2 May - WHO is notified of a cluster of severe acute respiratory illness aboard the vessel.
- 6 May - Laboratory testing identifies the Andes strain of hantavirus.
- 8 May - Three deaths confirmed. Six laboratory-confirmed cases, two further suspected cases.
- 10 May - The MV Hondius berths at Granadilla, Tenerife. Spanish public-health officials begin contact tracing.
- 11 May - Eighteen US passengers are repatriated by air, including one confirmed case and one symptomatic person under monitoring.
- 12 May - ECDC issues a rapid risk assessment classifying European public risk as very low. Contact tracing extends across at least eleven national authorities.
- 13 May - Spain confirms the first secondary case, a household contact of a returning passenger in Tenerife. Portugal joins the contact-tracing operation, bringing involved jurisdictions to twelve. WHO situation report DON599 is reissued with revised case definitions.
How did Andes virus get aboard?
The leading hypothesis is that one or more passengers were exposed during shore time in Patagonia before embarkation. Andes virus is endemic to southern Argentina and Chile; its natural reservoir is the long-tailed pygmy rice rat, Oligoryzomys longicaudatus. Once on board, the working assumption is that the virus spread among contacts in cabins and crew quarters.
It is also possible - though unproven - that the virus was carried by a stowaway rodent. Investigators are sampling pest-control logs and food-store areas of the vessel as a routine precaution.
How dangerous is Andes virus?
Andes virus causes hantavirus cardiopulmonary syndrome (HCPS), a severe illness that progresses from flu-like symptoms to a sudden, sometimes catastrophic, leak of fluid into the lungs. The case-fatality rate across South American outbreaks has historically sat between 25% and 40%.
The European Centre for Disease Prevention and Control has classified the risk to the wider European population as ‘very low’. The CDC has reached the same conclusion for the United States. Risk is concentrated among close contacts of confirmed cases, not the general public.
What you should do
- If you were aboard MV Hondius after 1 April 2026 and have any febrile or respiratory symptoms, contact public-health authorities in your country and mention the cruise by name.
- Household members of returning passengers should monitor themselves for 42 days, the upper bound of the Andes incubation period.
- If you live in or have travelled to Patagonia, follow standard rodent-exposure precautions in cabins, sheds and outbuildings.
- The general public - including people who simply share a city with returning passengers - does not need to take any action.
What we still don't know
How long did the index case incubate before symptoms? Was there a single super-spreader event? Did secondary transmission occur during one of the shore landings? Are any of the asymptomatic passengers carrying the virus undetected? Investigators are working through serology and contact tracing across at least eleven jurisdictions. This page will be updated as we learn more.
Editorial note
This article is intended as public information, not individual medical advice. If you are concerned about your symptoms, contact a qualified healthcare professional. We update outbreak reporting as new primary-source information becomes available.