Hantavirus on cruise ship: Experts probe rare human-to-human transmission

Health agencies across multiple countries are tracing passengers and probing the source of a deadly hantavirus outbreak linked to a cruise ship

  Health authorities across multiple countries are investigating whether a rare strain of hantavirus may have spread between passengers aboard a luxury cruise ship after at least three people died and several others fell ill during the voyage.

 

The outbreak, reported on the Dutch expedition cruise ship MV Hondius, has drawn global attention because human-to-human transmission of hantavirus is extremely rare. Investigators are now trying to determine whether passengers contracted the virus through close contact onboard or through exposure to contaminated rodent material.

 

The MV Hondius had been travelling from Argentina to Europe with around 150 passengers and crew members from multiple countries onboard. While the World Health Organization (WHO) has said the overall public health risk remains low, the incident has triggered a coordinated response involving health agencies across Europe, South Africa and the United States.

 

 

The ship was initially denied permission to dock in Cape Verde over public health concerns. It was later allowed to continue towards Spain’s Canary Islands, where passengers are expected to undergo medical examinations and further monitoring.

 

The WHO is now working with Spanish authorities, who will "welcome the ship to carry out a full epidemiological investigation, undertake complete disinfection of the vessel and assess the risk to passengers", said Dr Maria Van Kerkhove, WHO’s chief of epidemic and pandemic preparedness and prevention.

 

How did the virus reach the cruise ship?

 

The outbreak is believed to have begun after a Dutch couple onboard developed severe symptoms during the voyage. Both later died after being evacuated to South Africa for treatment. A German passenger also died, while several other passengers and crew members reported symptoms ranging from fever and fatigue to respiratory illness.

 

According to the WHO, at least two cases have been laboratory-confirmed and five others are suspected. One patient remains critically ill, while other infected individuals are under medical observation.

 

What is the rare hantavirus strain under investigation?

 

Hantavirus refers to a group of viruses mainly spread by rodents such as rats and mice. Humans can become infected after coming into contact with rodent urine, saliva or droppings, especially in enclosed or poorly ventilated areas.

 

In severe cases, the virus can lead to hantavirus pulmonary syndrome (HPS), a serious respiratory disease that can cause breathing difficulties and organ failure. Symptoms usually begin with fever, headaches, fatigue and muscle aches before progressing to coughing and shortness of breath.

 

The WHO has said the outbreak likely involves the Andes virus strain, which is mainly found in parts of Argentina and Chile and is one of the few hantaviruses known to occasionally spread through close human contact.

 

The MV Hondius began its journey in Argentina, where an Andes virus outbreak has been ongoing since last year. According to a Nature report, at least 20 deaths linked to the virus were recorded in the country between July 2025 and January 2026, while Argentina’s Health Ministry also reported a rise in the fatality rate.

 

Why are experts concerned?

 

The incident has drawn attention because human-to-human transmission of hantavirus remains extremely rare, prompting investigators to examine whether passengers were infected through contaminated rodent material or through limited transmission onboard the ship.

 

Dr Van Kerkhove said the incubation period of hantavirus, which can range from one to six weeks, suggests some passengers may have been infected before boarding the ship. She noted that the expedition cruise involved wildlife activities such as birdwatching and also stopped at several islands off the African coast where rodents are common.

 

However, she added that investigators still believe limited human-to-human transmission may have occurred among close contacts onboard, including passengers who shared cabins.

 

The outbreak is being closely monitored because hantavirus infections can become severe very quickly and there is currently no specific cure or approved vaccine for the disease.

 

Bryce Warner, a virologist at the University of Saskatchewan in Saskatoon, Canada, told Nature that health authorities are likely to collect samples from infected passengers and crew members to identify the source of the outbreak. He added that sequencing the detected viral particles could help determine the exact strain involved within a few days.

 

The WHO has also launched contact tracing efforts involving multiple countries because passengers onboard came from at least 23 nations.

 

Measures taken onboard

 

• Passengers and crew members have been advised to maintain frequent hand hygiene and remain alert for hantavirus symptoms
• Authorities recommend actively monitoring for symptoms for 45 days following possible exposure
• Crew members have been instructed to ensure proper environmental cleaning and ventilation across the ship, while avoiding dry sweeping that could spread contaminated particles into the air
• Anyone experiencing symptoms has been asked to immediately inform onboard medical staff and self-isolate
• Passengers and crew with respiratory symptoms have also been advised to follow respiratory etiquette and wear medical masks

 

Some seriously ill individuals, including crew members and the ship’s doctor, were evacuated to hospitals in the Netherlands and South Africa for treatment.

 

Should travellers be worried?

 

Global health agencies, including the WHO, have said the risk to the wider public remains very low. Authorities have not recommended travel restrictions, although they are monitoring passengers who recently travelled or came in contact with those on the ship.

 

Health authorities have also advised travellers and crew members returning from areas where hantavirus is known to circulate to remain vigilant for symptoms. People engaging in outdoor activities such as camping, hiking or eco-tourism in endemic regions have been urged to take precautions to minimise exposure to potentially contaminated materials.

   

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This report is for informational purposes only and is not a substitute for professional medical advice.