A cluster of cases linked to the Andes strain of hantavirus has drawn international attention after infections were detected among passengers and crew of the Dutch-flagged expedition ship MV Hondius. The voyage left Ushuaia, Argentina, on April 1. Since mid-April, health authorities report multiple illnesses and deaths among people who traveled on that cruise, and public-health agencies are tracing others who may have been exposed.
Where the outbreak began and current case status
Officials believe the initial infections occurred before boarding in Argentina. The first two confirmed cases were a married Dutch couple who had been birdwatching in Argentina, Chile, and Paraguay—areas where rodents that carry the Andes virus are known to live. From there, the virus appears to have spread to close contacts on board, and at least one member of the ship’s medical team became ill.
As of early May, WHO and national health agencies reported several people hospitalized, at least three deaths among the 147 passengers and crew, and other confirmed or suspected cases. A flight attendant who had contact with an infected passenger was hospitalized in Amsterdam for testing. If that test is positive, it would be the first reported transmission linked to someone off the ship. Several passengers who disembarked on April 24 in Saint Helena later flew home to a dozen countries; those travelers and others who had close contact with them are being traced and monitored.
What the virus is and how it spreads
The strain involved is the Andes virus, a species of hantavirus found in parts of Latin America. Unlike most hantaviruses, Andes virus is known to be capable of limited human-to-human transmission, but that transmission has historically required close, prolonged contact—such as household exposure, intimate partners, or caregivers—rather than casual contact in public places.
Hantavirus infection typically begins with nonspecific, flu-like symptoms that can progress to severe respiratory illness and acute respiratory distress. The illness can be serious: historically, hantavirus pulmonary syndrome (HPS) has a high case fatality rate. The incubation period for Andes virus is usually two to four weeks but can be as long as six weeks, meaning additional cases may still appear after an exposure event.
Rodent contact is the usual route of infection: exposure to infected rodent urine, droppings, or saliva (including bites) is the primary source. Human-to-human spread is rare and, when it has occurred, has generally involved close, prolonged contact. Evidence suggests droplets rather than aerosols are the likely mode in the uncommon person-to-person transmissions, so brief presence in the same room is less likely to cause infection.
Diagnosis and treatment
There is no specific antiviral treatment for hantavirus infection. Care in hospital focuses on supportive measures, particularly respiratory support and ventilation for severe cases. Early recognition and prompt medical care improve the chances of recovery.
Public-health response and travel implications
WHO and national agencies are conducting contact tracing and monitoring passengers, crew, and people who shared flights or other close-contact settings with those infected. Onboard the ship, remaining passengers were asked to stay in cabins while cleaning and infection-control measures were carried out; infectious-disease specialists joined the vessel to assist. The ship planned to call at the Canary Islands for a full epidemiological investigation and to begin repatriation of travelers once cleared locally.
Despite the seriousness of the illnesses on the ship, global health officials have assessed the public-health risk to the general public as low. Hantavirus is not spread by people without symptoms, and transmission has required close, prolonged contact in documented instances. Past outbreaks involving human-to-human transmission were controlled with quarantine and contact tracing.
Practical advice for travelers
– Do not cancel routine travel to South America based on this event alone. Authorities say there is no evidence of a widespread hantavirus outbreak on the continent.
– Avoid areas with obvious rodent infestations and places with poor sanitation. Hantavirus is primarily contracted through contact with rodent urine, droppings, or saliva.
– Maintain good hygiene: wash hands frequently, especially before eating, and avoid touching the face after being in potentially contaminated areas.
– On cruises or in remote lodgings, follow the vessel’s or venue’s health guidance, report any symptoms promptly to onboard medical staff, and follow instructions from public-health officials.
– If you had close contact with a confirmed case—such as household exposure, prolonged face-to-face contact, or caregiving—inform local health authorities and monitor for symptoms for up to six weeks.
Final notes
Health agencies emphasize that this outbreak behaves differently from respiratory viruses like SARS-CoV-2. Transmission appears limited to close contacts rather than casual encounters, and the risk to the wider public remains low. Travelers should take sensible precautions against rodent exposure and seek prompt medical attention if they develop fever, muscle aches, or respiratory symptoms after potential exposure. This is a developing situation; public-health agencies continue to investigate and will update guidance as new information becomes available.