Health officials confirmed 11 hantavirus cases linked to the MV Hondius cruise ship, including three deaths, as evacuation efforts concluded in Tenerife, Spain.
Unlike typical hantavirus spread from rodent droppings, the Andes virus detected on the vessel can rarely transmit between humans; World Health Organization Director-General Tedros Adhanom Ghebreyesus warned that new cases may emerge in the coming weeks given the 42-day incubation period.
Spain’s Health Ministry reported Tuesday that a passenger evacuated to Madrid tested positive for the virus while in quarantine; numerous nations instituted active monitoring requiring daily health checks either at home or in specialized facilities.
Eighteen American passengers evacuated to facilities in Nebraska and Georgia remain under observation, with some placed in biocontainment units “out of an abundance of caution,” the Department of Health and Human Services said.
The Hondius is currently sailing to Rotterdam, Netherlands, for cleaning after completing repatriation of passengers from over 20 countries, with the remaining 27 crew members expected to arrive on May 17.
Dr. Todd Ellerin of South Shore Health said the infections are very scary for both patients and doctors because of the high mortality rate.
He also said the virus has a long incubation period.
Despite the concerns, federal health officials said the hantavirus risk to the general public is still very low.
Three people have died.
Henry said nine people have tested positive, including a recent case in France from someone who just returned from the cruise ship. She added there are multiple people still in hospital, including one in South Africa, two in the Netherlands, one in Switzerland and the most recent case in France.
So, what is hantavirus?
The World Health Organization says it’s a group of viruses carried by rodents that can cause severe disease in humans, and people usually get infected through contact with rodents or their urine, droppings, or saliva.
To date, human-to-human contact has only been documented in the Andes virus in the Americas and remains uncommon, the WHO’s fact sheet says.
Transmission between people has been associated with close and prolonged contact.
Henry said hantavirus doesn’t spread the same way as coronavirus, influenza, or measles, which have also seen rising rates in recent years.
“It’s not highly transmissible and we know that too,” she explained. “And it’s not what we would consider a disease of pandemic potential. It is, however, a very serious illness.
Hantavirus vs. COVID
Henry explained that the SARS-CoV-2 virus is one that causes an infection in the upper respiratory system first, so people “shed” – or spread – quite a lot of virus through their secretions from talking, sneezing, coughing or singing.
“It spreads through the air, and we know that especially the Omicron strain of the coronavirus, it can last in the air for some time and spread quite rapidly to people, especially in closed environments with poor ventilation.
She pointed to the COVID-infected cruise ship in 2020 where the virus spread quickly, even among people who hadn’t been in contact with someone infected. She said it likely spread through the ventilation system.
Typical COVID symptoms include fever, chills and a sore throat. However, there can be less-common symptoms, such as muscle aches, severe fatigue or tiredness, runny or blocked nose, tight chest or chest pain or loss or change of sense of taste or smell.
Hantavirus is quite different, she said. It causes infections that are more deep in the lungs, and can cause kidneys to fail.
WHO says that in humans, symptoms usually begin between one and eight weeks after exposure depending on the type of virus. Those symptoms can typically include fever, headache, muscle aches and gastrointestinal symptoms, such as abdominal pain, nausea or vomiting.
Henry said there’s a global consensus that the first two hantavirus cases were contracted in Argentina – they were travelling through South America prior to the MV Hondius cruise – where there has been a “dramatic increase” in the number of people with hantavirus over the last little while.
“Then because it has such a long incubation period, they develop symptoms on board the cruise ship.”
Henry added that health officials do know quite about about hantavirus and the Andes strain so far, with whole genome sequencing being done. The strain, she said, hasn’t changed a lot, which is “something that is quite different” compared to COVID.
“That tells us that the virus isn’t mutating and causing different sources becoming more infectious or anything like that, so that’s also reassuring. Unlike the coronavirus, as we remember, SARS-CoV-2 it changed quite a lot very rapidly over time.”
But WHICH version is the Hantavirus currently being discovered and treated?
The Andes virus differs from the more commonly known North American hantavirus—Sin Nombre virus—and from Old World hantaviruses in several critical ways.
If you mean Sin Nombre virus (North America)
This is the “classic” hantavirus most Americans know from the 1993 Four Corners outbreak.
The person-to-person transmission capability is the single most important distinction. It is why the cruise ship cluster is epidemiologically possible at all; Sin Nombre virus would not produce a shipboard outbreak because it cannot chain through human contacts .
If you mean Old World hantaviruses (Hantaan, Seoul, Puumala)
These are the “original” hantaviruses discovered during the Korean War in the 1950s.
Both Old World and New World hantaviruses start with flu-like symptoms (fever, muscle aches), but they diverge sharply in the second phase: Old World viruses attack the kidneys and cause hemorrhaging, while New World viruses like Andes and Sin Nombre flood the lungs with fluid and cause cardiogenic shock .
Andes virus, the version affecting the ship visitors, is unique among all hantaviruses because it combines the high lethality of New World pulmonary syndrome with the rare ability to spread directly from person to person. Sin Nombre virus, despite causing the same clinical syndrome, cannot do this. That biological difference—not a mutation or new variant—is what made the cruise ship outbreak possible.
The hantavirus outbreak on the cruise ship has been definitively identified as the Andes virus (Andes hantavirus).
On May 6, 2026, the World Health Organization confirmed that the strain responsible is the Andes virus—the only hantavirus species known to be capable of limited human-to-human transmission through close and prolonged contact. The CDC issued a similar confirmation, stating the outbreak is caused by Andes virus, which can lead to hantavirus pulmonary syndrome (HPS).
Genetic sequencing and PCR testing have verified this. As of May 8, all six laboratory-confirmed cases were identified as Andes virus . The outbreak is believed to have originated from exposure in South America before boarding: the first victims, a Dutch couple, had spent weeks traveling through Argentina, Chile, and Uruguay on a bird-watching trip in areas where the pygmy rice rat (the rodent reservoir for Andes virus) is present. The cruise ship departed from Ushuaia, Argentina.
The Andes virus is unique among hantaviruses because it is the only strain with documented person-to-person transmission, though such transmission is rare and typically requires close, prolonged contact.
Recent genetic sequencing shows the virus is similar to known Andes viruses circulating in South America and is not a new variant .
