Three people have died following a suspected hantavirus outbreak on a cruise ship, the MV Hondiusin the middle of the Atlantic Ocean. At least one other passenger is in intensive care in South Africa. In addition, a man who was traveling on the cruise ship was hospitalized in Zurich, Switzerland, the Swiss Ministry of Health announced this Wednesday, May 6.
In a press release published on social networks on Sunday, May 3, the World Health Organization (WHO) first announced these deaths and indicated that this rare hantavirus disease had been confirmed in the laboratory in one of the cases. Since then, a second case of hantavirus was confirmed on Tuesday May 5, then the third in Switzerland.
WHO is aware of and supporting a public health event involving a cruise vessel sailing in the Atlantic Ocean. To date, one case of hantavirus infection has been laboratory confirmed, and there are five additional suspected cases. Of the six affected individuals, three have died… pic.twitter.com/SqMAAZzoID
— World Health Organization (WHO) (@WHO) May 3, 2026
Authorities are currently investigating five other suspected cases among passengers on the MV Hondiusimmobilized off the coast of Cape Verde, the arrival point of the cruise which left Ushuaïa (Argentina), at the beginning of April. So, what is hantavirus disease? And why can it be fatal? As the investigation progresses, here’s what we know.
What do we know about hantaviruses?
Hantaviruses cause rare but serious pulmonary syndromes and can also cause severe bleeding and fever, although hantavirus illness can be fatal.
When they are zoonotic, these viruses cause two types of syndromes in humans, indicates the Pasteur Institute: either hemorrhagic fever with renal syndrome caused mainly by “Old World hantaviruses”, or cardiopulmonary syndrome caused mainly by “New World hantaviruses”. Both syndromes can be caused by the same viral species. It is a relatively rare disease in certain countries – around a hundred hospitalized cases detected on average in France annually and around fifty per year in the United States – but more common in others: several hundred to thousands of cases per year in Germany and Scandinavia.
Hantaviruses are transmitted by rodents, such as mice and rats, primarily through the urine and feces of infected animals. They are generally not transmitted from one human to another, except in rare cases.
It is estimated that there are between 150,000 and 200,000 cases of hantavirus infection worldwide each year. They are less contagious than airborne viruses such as Covid-19 and viruses influenza (which transmit the flu, editor’s note), because they are generally not transmitted from one person to another.
What makes these hantaviruses deadly?
There are two main types of hantavirus, each with different symptoms. THE hantavirus pulmonary syndromewhich affects the lungs, is mainly present in the United States. If a person is infected with this type of hantavirus, they will likely experience a cough and shortness of breath within a few days.
As the disease progresses, symptoms such as fatigue, fever and muscle pain may appear. Headache, dizziness, nausea, vomiting, and abdominal pain may also occur. This is the most deadly strain of hantavirus. Unfortunately, about 38% of people who experience these symptoms die from the disease.
There is no specific treatment or cure for either type of hantavirus. However, early medical attention can increase the patient’s chances of survival.
There hemorrhagic fever with renal syndrome is primarily found in Europe and Asia, but the strain known as “Seoul virus” has spread throughout the world. This form of hantavirus mainly affects the kidneys.
People usually develop symptoms within two weeks of exposure to the virus. Early symptoms include severe headache, abdominal pain, nausea and blurred vision. More advanced symptoms include low blood pressure, internal bleeding, and even acute kidney failure. This disease can be caused by different viruses, some of which are more deadly than others, meaning that between 1% and 15% of cases can be fatal.
Unfortunately, there is no specific treatment or cure for either type of hantavirus. However, early medical attention can increase the patient’s chances of survival. This may include the use of ventilators, oxygen therapy and dialysis. Regarding the cruise ship, authorities are continuing their investigations to determine what type of hantavirus the passengers were exposed to.
#Hantavirus : WHO suspects human-to-human transmission, investigates flight
“We want you to know that we are working with the ship’s operators and collaborating with your countries. We hear you. We know you are afraid” – @WHOhttps://t.co/EMBI9qrOhc— UN Info (@ONUinfo) May 6, 2026
How did the virus end up on a cruise ship?
In an enclosed environment such as a cruise ship, passengers could have contracted hantavirus in two ways. According to a first hypothesis, they were exposed to the virus during a shore excursion.
Another hypothesis: rodents could have entered the ship in the cargo, then transmitted the disease to passengers through their contaminated urine or excrement. Other factors, such as hygiene standards and food storage practices, may have contributed to the faster spread of infection.
To stem this suspected outbreak, authorities must first ensure that all rodents are safely captured and removed from the ship. They must then monitor all passengers to detect possible symptoms linked to hantavirus infection. The virus is diagnosed using a PCR test, similar to those used to diagnose viruses such as Covid-19.
Knowing that there is no specific treatment for the disease, authorities must help infected passengers manage their symptoms. This involves checking that they are breathing normally and that their kidneys are working properly.
So, should we be worried?
Although worrying, cases of hantavirus infections remain extremely rare. However, because hantavirus disease can present with symptoms similar to other respiratory conditions, it is recommended that you always seek medical attention if you experience symptoms.
If you have stayed in areas where this type of virus is present and you suffer from shortness of breath, fever or any other symptoms that resemble flu-like illness, consult your doctor.
