The hantavirus outbreak tied to the expedition ship MV Hondius has left authorities and passengers on edge, with confirmed cases and deaths prompting state monitoring, quarantine measures and renewed attention to how the virus spreads and how dangerous it can be.
The incident began on a voyage from Argentina across the Atlantic and has since been linked to several illnesses and fatalities among passengers. Reports say multiple people became sick and at least three died, while health agencies sift through travel histories and test results to map the scope.
State health officials in places like Texas, Virginia, Georgia, Arizona and California have been tracking passengers who returned from the ship to watch for symptoms and prevent further spread. Public health teams are focused on early detection because early presentation can look a lot like common flu or other respiratory infections.
“Most of these cases have been west of the Mississippi River, and classically the risk factors are being in contact with feces and urine from rodents,” Marcos told Fox News Digital. That observation echoes decades of U.S. data showing hantavirus tends to appear in particular regions and under familiar exposure scenarios tied to rodents.
The strain most often seen in the U.S. is Sin Nombre, which does not spread from person to person, and most hantaviruses are transmitted when people breathe in tiny particles contaminated with rodent urine, droppings or saliva. “Some people may have mild disease, so not everybody will be very, very sick,” the doctor noted, which complicates detection and isolation early on.
“The only proven human-to-human transmission has been with the Andean virus from South America — and that’s what’s happening now,” Marcos told Fox News Digital, and that fact is central to how officials are approaching the cruise outbreak. Where human transmission is possible, close living conditions or extended contact become the highest risk settings rather than casual community encounters.
Symptoms often mimic the flu or COVID, including fever and muscle aches, and in the worst cases the infection can progress to hantavirus pulmonary syndrome, where lungs fill with fluid. “The mortality rate [among those with HPS] is between 30% and 60% — so yes, it’s a deadly virus,” the doctor added, which is why clinicians move quickly to supportive care when HPS is suspected.
“It has to be really, really close contact,” he said of transmission that involves humans infecting other humans, and he emphasized that airborne spread via droplets is “not as effective” as with influenza or COVID. That difference in transmission efficiency helps explain why experts see low pandemic potential even as they treat individual outbreaks seriously.
“For this cruise, it’s important to have people in quarantine for a period of time,” he said, because hantavirus can incubate for weeks. “The longest incubation period has been 56 days or so, so two months, roughly,” Marcos said. “But most cases will get sick within two to three weeks,” so monitoring and repeated checks are part of the response strategy.
Treatment options remain supportive rather than antiviral, meaning patients with severe lung involvement may need ventilators and intensive care while the infection runs its course. “So what happens is the patient will end up in the hospital. We will do supportive care, which means if your lungs are full of fluid, you will require a ventilator until you know the virus runs its course,” Marcos said, underscoring the strain severe cases can place on hospital resources.
Prevention advice stays straightforward: avoid contact with rodents or their droppings, use gloves and masks when cleaning spaces that might have been exposed, ventilate closed areas and wash hands frequently. Although there is no U.S. vaccine yet, researchers are working on options, and officials remain confident this kind of outbreak is unlikely to evolve into a widespread pandemic.
“I don’t feel a strong risk of a pandemic,” he told Fox News Digital. “The transmission is not like COVID. It’s very different.” “I really think this is going to go away in the next two to three weeks, and we will know exactly the number of cases,” he added, as public health teams continue contact tracing and monitoring to close the investigation.
