Hantavirus on a Cruise Ship Is Unusual: Here’s What to Know
Hantavirus is not the kind of virus typically associated with cruise ship outbreaks, which is what makes the reported cluster aboard the MV Hondius so unusual.
Published May 4, 2026 [Updated May 5, 2026]
By Syra Madad, D.H.Sc., M.Sc., MCP, CHEP
The World Health Organization (WHO) now reports seven cases linked to the cruise ship: two laboratory-confirmed hantavirus infections and five suspected cases, including three deaths, one critically ill patient and three people with mild symptoms. The ship, carrying 147 passengers and crew from 23 nationalities, is moored off Cabo Verde while investigations continue.
Three people aboard the Atlantic expedition cruise have died in a suspected hantavirus cluster. As of May 4, two cases have now been laboratory-confirmed, with five others classified as suspected cases. Illness onset occurred between April 6 and April 28, with symptoms including fever, gastrointestinal illness, pneumonia, acute respiratory distress syndrome and shock.
Unlike norovirus or many respiratory viruses that can spread quickly in close quarters, hantaviruses are usually rodent-borne. People are most often infected after exposure to virus-contaminated rodent urine, droppings, saliva or dust, not through routine contact with other travelers.
That distinction matters. Investigators will need to determine where exposure occurred: on the ship, during a shore stop, through contaminated supplies or cargo, or through another route still under investigation. WHO says the vessel departed Ushuaia, Argentina, on April 1 and traveled through remote South Atlantic locations including Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena and Ascension Island. The extent of contact with local wildlife, or any exposure before boarding, remains undetermined. Andes virus, found in South America, is especially important to assess because it has been linked to person-to-person transmission in some circumstances.
Here are 3 things to know about hantavirus:
1. Hantavirus is rare, but it can be severe.
In the United States, 890 laboratory-confirmed hantavirus cases were reported from 1993 through the end of 2023. Hantavirus pulmonary syndrome, the severe lung illness caused by some hantaviruses, is fatal in nearly 4 in 10 infected people. Globally, hantavirus infections remain relatively uncommon, but the burden varies by region: an estimated 10,000 to more than 100,000 infections occur each year worldwide, with the largest burden in Asia and Europe. Case-fatality rates range from less than 1% to 15% in Asia and Europe and can reach up to 50% in the Americas. Early supportive care and rapid transfer to a facility with intensive-care capacity can improve survival.
2. Most hantaviruses do not spread from person to person.
Hantaviruses are mainly spread by rodents. People can become infected when fresh or dried rodent urine, droppings or saliva are disturbed and virus-containing particles are inhaled. Most hantaviruses are not transmitted between people; Andes virus, found in parts of South America, is the key exception with documented person-to-person spread. WHO currently assesses the risk to the global population from this event as low, but says the possibility of human-to-human transmission should be considered where Andes and potentially other South American hantaviruses are endemic.
3. Prevention is practical: reduce rodent exposure.
Hantavirus prevention starts with keeping rodents out of homes, cabins, ships and workspaces, and avoiding contact with areas they may have contaminated. The virus can spread when particles from infected rodent urine, droppings or nesting materials become airborne and are inhaled, especially during cleaning or disturbance of enclosed spaces.
Hantavirus may be rare, but it has long produced unusual and instructive cases in the United States. The disease was first recognized in the U.S. after a 1993 outbreak in the Four Corners region, where investigators linked severe respiratory illness to a newly identified hantavirus later named Sin Nombre virus. More recently, the CDC reported a Louisiana case of Bayou hantavirus cardiopulmonary syndrome, a reminder that hantavirus risk is not confined to the rural West. And in 2017 on Long Island, researchers documented infection with New York orthohantavirus in a woman with kidney and bleeding complications, showing that hantaviruses can surface in places many people would not associate with the disease. New York State also notes that while most U.S. cases occur west of the Mississippi River, sporadic cases have been reported in eastern states, including New York.
These cases underscore the central point: hantavirus is rare, but it can emerge in unexpected places when people encounter rodent-contaminated environments.
The priority now is straightforward: find the source, identify the virus, protect those at risk and communicate clearly without fueling alarm. That work is now underway through a coordinated international response involving WHO and authorities in Cabo Verde, the Netherlands, South Africa, Spain, the United Kingdom and Argentina, with case isolation, medical evacuation, contact tracing, laboratory testing, sequencing and metagenomic analysis ongoing.
This is an evolving story. Updates may be added as the World Health Organization (WHO) releases more information.
