In early 2025, a rare outbreak of hantavirus occurred aboard the cruise ship MV Hondius, affecting eight passengers and leading to three deaths. The virus, transmitted by rodents, raised concerns about a potential new pandemic. However, health experts stress that this isolated incident is not a cause for global alarm. Below, we answer the most pressing questions about the outbreak, the virus, and the steps being taken to ensure safety.
What exactly is hantavirus?
Hantaviruses are a family of viruses that naturally infect rodents, such as rats and mice, without causing them harm. Humans can contract the virus through direct contact with rodents or their droppings, urine, or saliva. Once transmitted, the virus can cause severe illnesses. In the Americas, certain strains lead to hantavirus cardiopulmonary syndrome, a condition affecting the heart and lungs with a fatality rate as high as 50%. Symptoms often begin with fever and muscle aches, quickly progressing to respiratory distress. The strain involved in this outbreak is the Andes virus, which is unique because it can also spread from person to person under close-contact circumstances.
How many cases were reported on the cruise ship?
As of early May 2025, eight passengers on the MV Hondius have contracted hantavirus, with three fatalities. The first case involved a man who developed respiratory symptoms on April 6 and died five days later. His wife, who left the ship at Saint Helena, fell ill during a flight to Johannesburg and died on April 26. A third passenger, who became symptomatic on April 28, died on May 2. Four additional passengers were evacuated for medical care—three to the Netherlands and one to South Africa. An eighth person, who had left the ship in Saint Helena, later tested positive for the Andes virus in Zurich, Switzerland, highlighting the virus’s ability to travel with infected individuals.
What makes the Andes virus different from other hantaviruses?
The Andes virus, a specific strain of hantavirus, is notable for its ability to spread between humans, whereas most hantaviruses require direct rodent contact for transmission. This human-to-human transmission, however, is limited to close contact—such as caring for an infected person or living in the same household. This trait was observed in previous outbreaks in South America. In the cruise ship setting, the virus likely spread among passengers who were in close quarters, such as couples or shared cabins. Despite this capability, the virus does not spread rapidly through casual contact, making it far less contagious than viruses like influenza or SARS-CoV-2.
Could this outbreak lead to a new pandemic?
Health authorities, including the World Health Organization, have dismissed pandemic concerns for several reasons. First, the Andes virus is not new; scientists understand its behavior and have developed diagnostic tools. Argentina has already shared testing kits to assist in monitoring. Second, transmission requires prolonged, close contact, unlike the airborne spread of COVID-19. The outbreak on the MV Hondius is considered a “specific confined setting” where people live and interact in tight proximity. Outside such environments, the risk of widespread transmission is extremely low. As a result, experts do not expect a global health emergency to emerge from this event.
What measures are being taken to contain the outbreak?
The cruise ship MV Hondius is currently en route to the Canary Islands, where authorities are finalizing a safe disembarkation plan for remaining passengers and crew. Health officials are conducting contact tracing to identify anyone who may have been exposed. The ship has been placed under quarantine, and all individuals are being monitored for symptoms. In addition, South Africa, the Netherlands, and Switzerland are coordinating with international health bodies to follow up on evacuated patients. Diagnostic kits from Argentina are being used to confirm cases quickly. These steps aim to isolate the virus and prevent further spread beyond the ship.
What should travelers know about hantavirus risk on cruises?
While hantavirus infections are rare, cruise ships can present unique risks due to confined living spaces and potential rodent infestations. Travelers should stay informed about hygiene practices: avoid touching dead rodents or their droppings, wash hands frequently, and report any signs of pests to crew. The cruise industry has protocols for rodent control, but outbreaks like this underscore the importance of vigilance. However, the chance of encountering hantavirus on a typical cruise remains extremely low. Those concerned are advised to check travel health notices from organizations like the Centers for Disease Control and Prevention before embarking on any trip.