6 May 2026 – Swiss health authorities have confirmed that a man who recently returned from a cruise in South America has tested positive for hantavirus. The case is the first confirmed Swiss infection linked to an ongoing outbreak aboard the MV Hondius, a Dutch-flagged expedition vessel operated by Oceanwide Expeditions. Three people have died, and at least seven have been infected across the outbreak so far.
Switzerland’s Federal Office of Public Health (FOPH) confirmed the case through an official statement and said it is coordinating with the World Health Organisation and European health bodies.
“One person with a hantavirus infection is currently being treated at the University Hospital Zurich (USZ),” the government said. “The patient’s wife accompanied him on the trip. She has not yet shown any symptoms but is self-isolating as a precaution.”
The USZ is prepared to deal with such cases, is able to care for the patient, and guarantee the safety of staff and all patients. There is currently no danger to the Swiss public
WHO Director-General Tedros Adhanom Ghebreyesus addressed the outbreak on Wednesday, describing it as a “rare” event of human-to-human transmission while offering measured reassurance. “At this stage, the overall public health risk remains low,” he said.
Read More: WHO announcement on Hantavirus
What is the Andes strain? A Rare and Dangerous Strain Found in Argentina, Chile
The outbreak involves the Andes strain of hantavirus, a pathogen that sets it apart from most hantavirus infections. While the majority of hantavirus cases result from exposure to infected rodents, the Andes strain, found primarily in Argentina and Chile, is one of the few variants capable of spreading between humans through close, prolonged contact such as sharing bedding or food.
The strain carries an estimated mortality rate of approximately 40%. It can also remain dormant for up to eight weeks, meaning passengers and crew aboard the MV Hondius face an extended period of uncertainty and surveillance.
Clinical symptoms begin with fever and gastrointestinal distress before progressing rapidly to pneumonia, acute respiratory distress syndrome, and potentially fatal shock. The first patient in the current outbreak developed a fever on 6 April, deteriorated within days, and died on board on 11 April, before any testing had been performed.
Timeline of the Outbreak
The MV Hondius departed Argentina on April 1, 2026, carrying approximately 147 passengers and crew on a Southern Atlantic expedition route that included Antarctica. By early May, the voyage had become the focal point of an international health emergency.
A third patient developed a febrile illness on April 24. Three days later, they were medically evacuated to South Africa, where laboratory testing confirmed the Andes strain. The WHO was notified of the cluster on 2 May.
By 4 May, the WHO reported a total of seven cases — two laboratory-confirmed and five suspected — and three deaths.
Two passengers identified in South Africa included a British man currently in intensive care and a female passenger who died after evacuation. Three suspected cases from the Netherlands were transported back to Europe for treatment. The vessel itself is currently anchored off Cape Verde, West Africa.
Spain has agreed to receive the ship in the Canary Islands, though local officials have raised concerns about potential public health risks to residents.
International Response So Far
On board, all remaining passengers and crew are subject to 45-day symptom monitoring, enhanced cleaning and ventilation protocols, and isolation procedures for anyone showing symptoms. Medical masks are recommended for those with respiratory symptoms.
The FOPH has implemented the same 45-day surveillance window for close contacts of the confirmed Swiss case. Authorities are advising anyone who was aboard the MV Hondius to monitor for symptoms including fever, gastrointestinal distress, and breathing difficulties, and to contact a medical professional immediately if any arise.
Switzerland’s swift identification of the returning traveler reflects the country’s strong public health surveillance infrastructure and its capacity to test for rare pathogens. The FOPH’s rapid coordination with international bodies has been cited as a model for managing travel-linked infectious disease cases.
The source of the initial infection on the ship has not been definitively established. Genetic sequencing and further laboratory work are ongoing, and the total case count may rise as suspected cases undergo confirmatory testing. Health authorities across Europe continue to monitor the situation closely as the MV Hondius awaits its next port of call.
Read Government Announcement: Patient with a hantavirus infection being treated in hospital
