Three deaths and a rare virus: what happened on the MV Hondius cruise ship

Important: WHO assesses the risk to the general world population as low. Hantaviruses are usually transmitted to humans through contact with the excreta of infected rodents; limited human-to-human transmission has previously been described for Andes virus, but this is considered unusual.

Details

MV Hondius is a Dutch expedition vessel of Oceanwide Expeditions. It left Ushuaia in southern Argentina on 1 April 2026 and followed a route through Antarctica, South Georgia, Tristan da Cunha, St Helena, Ascension and on to Cape Verde. According to WHO, 147 people were on board: 88 passengers and 59 crew members from 23 countries.

The first known ill person, an adult male, felt symptoms on 6 April: fever, headache and mild diarrhoea. By 11 April, he had developed respiratory failure and died on board. At that time, the cause of death had not yet been determined.

The ship continued on its route. It was not until 24 April that the body of the deceased man was taken off the ship at St Helena, and his wife, who was already symptomatic, went ashore. On the flight to South Africa, she became worse; she died in hospital on 26 April. Her test later confirmed hantavirus infection.

Another passenger became ill after the ship left St Helena. He had a high fever, shortness of breath and signs of pneumonia. on 27 April, he was evacuated from Ascension Island to South Africa, where he was admitted to the intensive care unit. It was his positive test for hantavirus on 2 May that became one of the key signals for the international investigation.

A third death came later: an adult woman with signs of pneumonia died on 2 May after symptoms began on 28 April. As of 4 May, WHO said there were a total of seven cases - two laboratory-confirmed and five suspected - including three deaths. AP later reported that the number of confirmed infections rose to five, and three more patients were evacuated from the ship.

Why the virus was not immediately identified

The situation was complicated by the ship's route. The MV Hondius was far from major medical centres, calling at remote islands, and the symptoms of those who fell ill could initially look like other infections: fever, gastrointestinal manifestations, then pneumonia and respiratory failure.

AP notes that nearly a month passed between the time the first elderly passenger became ill and died in the South Atlantic and the first laboratory confirmation of hantavirus in South Africa - more than 3,500 kilometres from the ship.

Following the confirmation of hantavirus, authorities in several countries launched investigations and contact tracing. Among the parties involved, WHO listed Cape Verde, the Netherlands, Spain, South Africa, Spain and the UK. Passengers and crew on board were advised to limit contact as much as possible and stay in their cabins if possible.

What is known about the possible source

The source of the contagion has not yet been definitively identified. WHO indicates that epidemiological investigations are ongoing, including checking for possible contact between passengers and wildlife during the voyage or prior to landing in Ushuaia.

According to AP, one working theory of Argentine investigators is that the first ill couple may have become infected before boarding the ship, while birdwatching in the Ushuaia area. That theory is not yet the final conclusion of the investigation.

Why it matters

The story of MV Hondius shows how difficult it is to recognise a rare infection in the context of a long sea route, remote areas and an international mix of passengers. The disease can start non-specific and laboratory confirmation takes time and access to specialised tests.

That said, the situation does not represent a pandemic-level threat. Hantaviruses do not usually spread like influenza or coronavirus. The main route of infection is contact with the excreta of infected rodents, more often through inhalation of contaminated dust. Limited human-to-human transmission has been described for Andes virus, but WHO emphasises that the global risk from this event is now assessed as low.

Background

Hantaviruses are a group of viruses that can cause severe disease, including hantavirus cardiopulmonary syndrome. In severe cases, the disease progresses rapidly to pneumonia, respiratory failure, and shock. In the Americas, Orthohantavirus andesense, or Andes virus, is responsible for most cases of hantavirus pulmonary syndrome in South America.

For cruise ships, such cases are particularly challenging: there are many people from different countries on board, the journey may pass through remote areas, and passengers may disembark and continue travelling before the infection is recognised. Therefore, once the diagnosis was confirmed, authorities began tracking not only the people on board, but also those who had left the ship earlier.

Source

Key data - WHO Hantavirus cluster linked to cruise ship travel, Multi-country report dated 4 May 2026 and an Associated Press investigation into the chronology of the outbreak on the MV Hondius. WHO described the first seven cases, symptoms, ship itinerary and response; AP completed the picture with more recent data on confirmed infections, evacuations and the international investigation.