The World Health Organization confirmed five laboratory-proven hantavirus cases linked to an outbreak on the MV Hondius cruise ship, up from two earlier this week. The update came as the Dutch-flagged expedition vessel, carrying about 150 passengers and crew from 23 nationalities, continues its journey toward Spain's Canary Islands after stops in remote South Atlantic locations.

Three people have died from the illness, which health officials have identified as the Andes virus, a strain endemic to South America with a case fatality rate of around 40 percent. At least three additional suspected cases remain under investigation, bringing the total affected to eight. Illness onsets occurred between April 6 and 28, following the ship's departure from Ushuaia, Argentina, on April 1.

The MV Hondius had been scheduled for an Antarctic itinerary, including visits to South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena, and Ascension Island. Authorities in Cape Verde denied docking on May 4 but provided medical support while the ship anchored offshore. It is now en route to Granadilla port in Tenerife, where asymptomatic passengers may disembark, though Spanish citizens with symptoms face quarantine on a military base.

Symptoms reported include fever, gastrointestinal issues such as nausea and abdominal pain, headache, muscle aches, rapid progression to pneumonia, shortness of breath, and shock. The first death occurred on April 11, involving a Dutch man.

Investigators suspect initial exposure happened in Argentina before boarding, possibly during a bird-watching trip near a landfill where rodents could have been present. One case emerged in Switzerland from a passenger who flew home after an earlier leg of the voyage, prompting contact tracing. While hantavirus typically spreads from infected rodents via urine, droppings, or saliva, Andes virus is the only strain known for rare human-to-human transmission through close, prolonged contact early in illness.

WHO epidemic expert Maria Van Kerkhove stated, "This is not the next COVID, but it is a serious infectious disease." The agency assesses global risk as low and advises against travel restrictions. The European Centre for Disease Prevention and Control echoes that the risk to Europe's general population is very low with proper precautions.

No specific antiviral treatment exists; care is supportive, including oxygen, fluids, and intensive care if needed. Prevention focuses on rodent control, hand hygiene, avoiding contaminated areas, and isolation of cases. Evacuations have included airlifts to the Netherlands and South Africa for severe cases.

Argentina has seen a rise in hantavirus infections since June 2025, with 101 cases reported, double the previous year. Hantaviruses cause hantavirus pulmonary syndrome in the Americas, with global cases numbering in the tens of thousands annually, mostly in Asia and Europe, from different strains.