The hantavirus outbreak detected aboard the MV Hondius cruise ship triggered international health alarms and forced the World Health Organization (WHO) to activate epidemiological surveillance and contact-tracing protocols in several countries.
The vessel, carrying nearly 150 passengers and crew members, is currently sailing toward Tenerife after remaining anchored for several days off Cape Verde while some critically ill patients were evacuated and authorities assessed the scale of the outbreak.
The situation has raised concern because the confirmed cases involve the Andes variant, considered the only hantavirus strain with documented human-to-human transmission capability, although only infrequently, and the WHO has warned that “hantavirus is not like Covid,” in an attempt to send a reassuring message.
So far, several infections and at least three deaths linked to the outbreak have been confirmed, while international health authorities insist that the risk to the general population remains low as long as control and isolation measures are maintained.
Hantavirus basics: The Atlantic cruise ship outbreak that triggered a WHO alert
Hantavirus is a group of viruses transmitted mainly by infected rodents. People usually become infected by inhaling contaminated particles from the urine, saliva, or droppings of these animals. Infection can also occur by touching contaminated surfaces and then touching the mouth, nose, or eyes.
The disease is known for causing severe and potentially fatal respiratory illness. In the Americas, especially in countries such as Argentina, Chile, and parts of southern Brazil, the infection can lead to what is known as hantavirus pulmonary syndrome, a complication that rapidly affects the lungs and can cause severe respiratory failure.
The WHO reminded the public this week that there is no approved vaccine or specific antiviral treatment for the disease. Medical management is based primarily on intensive respiratory support and early detection.
One of the factors causing the greatest concern in the MV Hondius case is that laboratory tests identified the Andes variant of the virus. Experts stress that this strain is exceptional among hantaviruses because it can be transmitted from person to person under certain circumstances, especially through close and prolonged contact with infected patients.
However, international organizations have insisted that this is not a virus with a transmission capacity comparable to respiratory diseases such as COVID-19 or the flu. Documented interpersonal transmission usually requires close cohabitation, exchange of bodily fluids, or intense contact over several days.
Precisely for that reason, the WHO believes the outbreak will probably remain “limited” in scope, although it acknowledged that new cases could appear because of the incubation period and the close living conditions aboard an expedition cruise ship.
Hantaviruses are zoonotic viruses that naturally infect rodents and can occasionally spread to people.
Here’s what you need to know about #hantavirus: What they are, how they spread, the symptoms, and how to prevent infection pic.twitter.com/pduUjlwl2j
— World Health Organization (WHO) (@WHO) May 8, 2026
How the cases began on the cruise ship
The MV Hondius began its voyage on April 1 from Ushuaia, Argentina, on an expedition through the South Atlantic and polar regions. During the trip, the first symptoms began to appear among some passengers, initially interpreted as common respiratory illnesses.
As the days passed, several patients developed high fever, gastrointestinal problems, and a rapid progression toward pneumonia and acute respiratory distress. The first death occurred in mid-April, and other suspected cases later emerged, ultimately triggering the international alert.
Investigations suggest that the outbreak most likely did not originate on board the ship, but rather before embarkation or during one of the stops made in South America. The WHO and various international health authorities continue to conduct contact tracing across several continents because of the wide range of nationalities represented on the cruise ship.
After several days of uncertainty and diplomatic negotiations, Spain agreed to receive the cruise ship in Tenerife under a broad health operation coordinated with the WHO. The ship will not dock directly at port, but will instead remain anchored while medical checks and phased evacuation procedures are carried out.
Spanish authorities prepared special protocols to prevent any risk of community transmission. Passengers will undergo medical evaluations before leaving the vessel, and many will be repatriated directly to their countries of origin under health supervision.
The Spanish government insists that the risk to the population of the Canary Islands is very low, although the operation has generated political and social concern in Tenerife, where some sectors initially questioned the decision to allow the ship to arrive.
What are the most common symptoms
The initial symptoms of hantavirus can easily be confused with other viral infections. The disease usually begins with fever, severe muscle pain, fatigue, headache, and general malaise.
In many cases, nausea, vomiting, diarrhea, and abdominal pain also appear. The most serious problem occurs when the virus affects the lungs and causes fluid accumulation, which progressively makes breathing difficult.
Specialists warn that deterioration can be very rapid. Some patients go from presenting mild symptoms to requiring intensive care in just 24 to 48 hours. That is why health authorities stress the importance of seeking immediate medical attention for any compatible symptoms after having been exposed to a confirmed or suspected case.
The WHO maintains active international surveillance while monitoring passengers and crew continues. Experts consider that the MV Hondius episode represents one of the most unusual hantavirus outbreaks recorded outside South America, both because of the maritime setting and the possible person-to-person transmission in a closed space.
Even so, health agencies emphasize that there are no signs of a global threat or widespread transmission. The main focus remains on quickly identifying possible close contacts and preventing new infections during the disembarkation and repatriation of travelers.