A rare outbreak of the Andes strain of hantavirus aboard the Dutch expedition cruise ship MV Hondius has been linked to at least eight confirmed or suspected infections and three deaths, triggering contact tracing across multiple countries.
The Andes strain remains the only hantavirus with documented human-to-human transmission under close-contact conditions. The World Health Organization said the risk to the general public remains low, while health agencies in Europe, Africa, Asia, and North America continue monitoring exposed travelers and their contacts.
Investigators in multiple countries are examining whether the outbreak began through environmental exposure in South America before passengers boarded the vessel, followed by possible secondary transmission among close contacts during the voyage.
The Dutch expedition vessel MV Hondius, operated by Oceanwide Expeditions, departed from Ushuaia on April 1, 2026, for its Atlantic Odyssey expedition.
According to Oceanwide Expeditions, the vessel was carrying 88 passengers and 61 crew members, around 149 people in total, representing 23 nationalities. The itinerary included Antarctica, the Falkland Islands, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena, Ascension Island, Cape Verde, and the Canary Islands.
WHO investigators later said the likely index cases, a Dutch couple, may have been infected before boarding in Argentina.
A 69-year-old Dutch passenger developed fever, headache, abdominal pain, and diarrhea before becoming critically ill and dying onboard on April 11.
At that stage, the exact cause of illness remained unknown, and the ship continued its scheduled voyage while the patient’s body remained onboard.
When the ship reached Saint Helena on April 24, the first victim’s body was removed for repatriation to the Netherlands.
Soon after disembarking with her husband’s body, his 69-year-old wife developed symptoms and later collapsed at O.R. Tambo International Airport before a scheduled flight home.
She was hospitalized in Johannesburg and later died. Laboratory testing subsequently confirmed infection with the Andes strain of hantavirus.
During the voyage between Saint Helena and Ascension Island, a British passenger developed severe respiratory symptoms.
South African health authorities later confirmed the passenger tested positive for hantavirus and was admitted to intensive care in Johannesburg. WHO later said the patient’s condition was improving.
A German passenger died onboard on May 2.
Oceanwide Expeditions said the exact cause of death remained under investigation at the time, though health authorities later linked the death to the broader outbreak investigation.
As multiple passengers developed similar symptoms, international health authorities were notified.
Laboratories in South Africa and Switzerland confirmed the virus involved was the Andes strain of hantavirus, the only hantavirus known to spread between humans.
WHO said three deaths and five additional illnesses had been identified. Among those who developed symptoms were two crew members, including the ship’s doctor.
As the ship approached Cape Verde, authorities coordinated emergency medical transfers.
On May 6, three medically unstable individuals were evacuated from the vessel.
According to Reuters, two patients were flown to the Netherlands and one to Germany for specialized treatment. Separate reporting identified one of the evacuated patients as the ship’s doctor. Oceanwide Expeditions later confirmed that two evacuated patients had reached the Netherlands while a third evacuation flight was delayed.
Passengers remained largely isolated in their cabins while health authorities continued testing and infection control measures onboard. Reuters reported medics in protective equipment treating sick passengers while the ship remained off Cape Verde.
By May 7, health authorities reported eight linked cases, including five laboratory-confirmed infections and three suspected cases, including three deaths.
Oceanwide Expeditions said no passengers currently onboard were showing symptoms.
The ship departed Cape Verde and began sailing toward Santa Cruz de Tenerife, where passengers are expected to undergo medical assessment before repatriation. Spanish authorities said 14 Spanish nationals from the ship would undergo quarantine and health monitoring after arrival.
WHO officials cautioned that additional cases may still emerge in the coming weeks because the virus can incubate for up to six weeks. Maria Van Kerkhove, WHO’s head of epidemic and pandemic preparedness, said the agency does not anticipate a large epidemic and stressed that the outbreak is not comparable to COVID-19.
WHO continues to classify the risk to the global population as low while investigations into possible human-to-human transmission continue.
Also see: Hantavirus Outbreak in California: 3 Deaths Linked to Gene Hackman's Wife's Passing
According to Oceanwide Expeditions, the MV Hondius was carrying 88 passengers and 61 crew members, bringing the total number onboard to approximately 149 people.
Health officials in the United States later confirmed that American travelers had also been onboard. Public health agencies in Georgia, California, and Arizona said residents from their states were among the passengers and were being monitored after returning home.
By May 7, public health agencies in at least 12 countries were tracing passengers or close contacts connected to the ship. These included the United States, United Kingdom, France, Denmark, Switzerland, the Netherlands, Singapore, and Spain.
Authorities said at least 29 passengers from 12 countries had already disembarked in Saint Helena on April 24 before the outbreak was formally confirmed, prompting retrospective contact tracing across multiple jurisdictions.
Two British nationals were instructed by the UK Health Security Agency to self-isolate for 45 days after possible exposure.
Spanish authorities confirmed that 14 Spanish passengers would undergo quarantine after arrival from the Canary Islands, while Dutch authorities also hospitalized a KLM Royal Dutch Airlines crew member after possible exposure during transport of an infected passenger.
The outbreak has also raised questions about the timing of clinical escalation and evacuation measures.
According to Reuters interviews with passengers, some travelers expressed concern that the ship continued following its scheduled itinerary for nearly two weeks after the first passenger died on April 11, before broader international public health measures were activated.
Passengers told Reuters that symptomatic individuals were initially managed onboard while the vessel continued toward scheduled stops, including Saint Helena.
Oceanwide Expeditions said it followed onboard medical protocols, isolated symptomatic individuals, consulted infectious disease experts, and coordinated with national health authorities as the cluster evolved. WHO and national agencies have not announced any formal findings of procedural violations as investigations continue.
See also: The Public Health Officer Who Travels around the World on a Cruise - Dr. Parvani Laad
Hantaviruses are a group of rodent-borne viruses that usually spread when people inhale microscopic virus-containing particles from infected rodent urine, saliva, or droppings.
The Andes virus, found mainly in Argentina and Chile, differs from other hantaviruses because it has shown documented human-to-human transmission, usually through prolonged close contact involving family members, caregivers, or people sharing enclosed spaces.
According to WHO, the incubation period ranges from one to eight weeks, and symptoms may include:
Fever
Chills
Severe muscle pain
Headache
Fatigue
Nausea
Vomiting
Abdominal pain
Shortness of breath
As the illness progresses, patients may develop hantavirus pulmonary syndrome, where fluid accumulates in the lungs and breathing becomes difficult.
CDC data cited by The New York Times show case fatality rates can reach up to 15 percent in Europe and Asia and up to 50 percent in the Americas. There is no specific antiviral treatment. Management depends on supportive care, including oxygen therapy, intubation, fluid replacement, and medications to support organ function.
Clinical reviews published by JAMA Network report mortality rates of 30 to 40 percent in severe pulmonary cases.
Investigators have not yet completed genomic mapping to confirm exact transmission chains onboard.
However, WHO investigators reported no evidence of rodents onboard the ship, increasing suspicion that the first exposure occurred before embarkation, followed by possible secondary transmission among cabin mates or close contacts.
See also: Norovirus Outbreak Strikes Royal Caribbean Cruise Ship; Over 70 Fall Ill
World Health Organization. “Hantavirus Fact Sheet.” Accessed May 7, 2026. https://www.who.int/news-room/fact-sheets/detail/hantavirus
JAMA Network. “Hantavirus Pulmonary Syndrome Review.” 2026. https://jamanetwork.com/journals/jama/fullarticle/2834395
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