In May 2026, amid news of a hantavirus outbreak on the MV Hondius cruise ship in the Atlantic Ocean, a claim (archived) circulated online that the outbreak marked the first time the virus had spread from one person to another.
The claim circulated after Maria Van Kerkhove, the director of Epidemic and Pandemic Preparedness and Prevention at the World Health Organization, said during a news conference on May 5, 2026, that the organization believed there had been human-to-human transmission of the rare virus aboard the ship.
As of this writing, eight people who had traveled aboard the MV Hondius had suspected hantavirus infections, three of whom had died, according to the WHO (archived).
One X user who shared the claim about hantavirus wrote:
Hantavirus is incredibly deadly.
One of the only reasons that we don't have an issue with it, is we've never seen any outbreaks manage to evolve human-to-human transmission before.
It's always been rodent-to-human contact.
If we have H2H in Hantavirus that ship needs to be stranded at sea until every, single, person is cleared.
Because that would make the previous pandemic look like childs play.
(@adamscochran, accessed via X)
Similar claims that hantavirus had not previously spread between humans circulated on Facebook (archived) and Threads (archived).
These claims were false. Researchers have known for at least 30 years that one variant of hantavirus can spread between people,
According to South African health authorities and the WHO (archived), this was the same strain of hantavirus that laboratories found in the MV Hondius outbreak
Though ANDV can spread from person to person, the WHO called such transmission "uncommon." Van Kerkhove said on May 5, 2026, that the WHO believed person-to-person transmission took place only between "really close" contacts like a married couple or people who shared cabins, a claim backed by previous ANDV research.
According to its latest Disease Outbreak News bulletin on May 4, 2026, the WHO found a low risk to the global population from the hantavirus outbreak on board the MV Hondius cruise ship.
Argentinian studies found ANDV spreads between people through air
According to the WHO, hantaviruses are a group of viruses carried by rodents that can cause severe disease in humans. Humans usually contract hantavirus through contact with infected rodents or their urine, droppings or saliva.
In the Americas, hantavirus infections can cause hantavirus cardiopulmonary syndrome, a condition that affects the lungs and heart. In Europe and Asia, hantavirus infections can cause haemorrhagic fever with renal syndrome, which primarily affects the kidneys and blood vessels.
Researchers historically thought the viruses were entirely zoonotic, meaning they only spread from animals to humans. However, in 1998, researchers studying a hantavirus outbreak in El Bolsón, Argentina, in 1996, published evidence of what they called "the first hantavirus in the world associated with a severe, predominantly pulmonary illness transmitted person to person."
That virus was the then newly recognized Andes virus, or ANDV.
Paula J. Padula et al., who wrote the 1998 study published in the peer-reviewed journal Virology, found that 16 cases researchers investigated all involved a single variant of hantavirus. The people infected lived across a span of
Padula's research suggested ANDV could create three-to-four-person transmission chains through close physical contact, though the study could not establish exactly how the transmission happened.
Padula co-authored another study published in 2010 in the peer-reviewed journal Emerging Infectious Diseases that looked at more than 700 hantavirus cases in Argentina between 1995 and 2018 and found that around 2.5% of those cases were caused by person-to-person transmission.
A further study published in 2020 in the respected, peer-reviewed medical journal The New England Journal of Medicine found person-to-person transmission in a hantavirus outbreak in Epuyén, Argentina, in late 2018. That study found that three "super-spreaders" of ANDV who attended social events eventually led to 34 cases and 11 deaths.
In the Epuyén study, researchers also found that requirements from public health officials for cases or contacts to self-isolate and quarantine had "most likely" helped stop further spread, since it appeared the virus spread through "inhalation of droplets or aerosolized virions" (aerosolized virus particles).
The study also suggested that there was a short window during which people with ANDV could spread it to others. The study found that transmission in more than half of the cases occurred on the first day the infected person had a fever.
'This is not COVID,' communicable disease expert says
Though research suggests one variant of hantavirus can spread between people, studies and experts both agree it is a relatively uncommon event.
The Epuyén study found only one nosocomial infection, meaning one that happened in a hospital setting after admitting a patient, among more than 80 healthcare workers who cared for patients with ANDV at one hospital, even though they used limited personal protective equipment. The study found two such infections at a smaller, rural hospital. It also found that self-isolation and quarantine were highly effective measures against the spread of ANDV, halving the rate of spread.
The study found that those infected by the "super-spreaders" had generally been near them for extended periods of time at social events.
In the El Bolsón study (p. 325), people who contracted ANDV from another person had also generally been in close contact with that person, which included living together, working in an infected person's home or riding with an infected person in a car for an extended period of time.
Dr. Lucille Blumberg, the former deputy director at South Africa's National Institute for Communicable Disease, reportedly told CNN, "This is not Covid. This is really not Covid. It's not even influenza. It's an unusual person-to-person event, and it might have happened because, perhaps, of a closed environment on a ship."
Cruise ship headed for Canary Islands
At the time of this writing, the MV Hondius was sailing to the Canary Islands to dock, though the regional President Fernando Clavijo said he did not support the decision by Spain's government to allow the ship to travel there.
The ship had 149 passengers and crew on board as of May 4, 2026. By May 7, medical evacuation flights carrying three passengers and crew had left the ship, and two Dutch doctors had boarded to provide healthcare support for its journey to the Canary Islands.
Health authorities in Switzerland and the U.S. states of Georgia and Arizona were reportedly monitoring passengers who had disembarked MV Hondius before news of the suspected hantavirus cases broke.
A spokesperson for the Georgia Department of Public Health said it was monitoring two residents who returned home from MV Hondius. The residents were "in good health and show no signs of infection," according to a May 7 email. A spokesperson for the Arizona Department of Health Services told Snopes via email on May 7 that it was monitoring one former passenger who was "not symptomatic" at that time.
Swiss authorities said one former passenger who returned to Switzerland had tested positive for Hantavirus, according to the WHO.
According to a news release from Oceanwide Expeditions, the operator of the MV Hondius cruise, the company was working to contact passengers and crew who embarked or disembarked the ship since March 20. The WHO said symptomatic passengers on board the ship would take tests to find out if they had hantavirus and all passengers were practicing "maximal physical distancing."
It was unclear at the time of this writing what caused the hantavirus outbreak on the sh