What travellers should know about the Hantavirus, according to medical experts

Once the ship docks in the Canary Islands, Spanish authorities will do a full epidemiological investigation on the ship and begin repatriating travellers who are deemed fit to return home.

What exactly is hantavirus?

Hantavirus is an illness carried by rodents that can spread to humans and cause acute respiratory distress. The illness “initially causes flu-like symptoms that can progress to more severe illness where people have trouble breathing,” according to the CDC. It is fatal in nearly 4 in 10 people who become infected.

“Hantavirus is most commonly spread through contact with rodent urine, droppings, [and] saliva in the case of a bite,” says Dr. Carla McWilliams, chief of infectious disease, quality and safety for Cleveland Clinic Weston Hospital. “Though human-to-human transmission has been reported, it is considered to be quite rare.”

There are no specific treatments for hantavirus, but hospitals can offer supportive care, including breathing assistance and ventilation to help with severe respiratory symptoms. Starting care as early as possible is important to improve chances of recovery, the CDC says.

Did the hantavirus outbreak originate on the cruise ship?

International health officials believe that the initial infection of hantavirus occurred before passengers boarded the ship in Argentina on April 1. “With the timing of the incubation period of hantavirus, which can be anywhere from one to six weeks, our assumption is that they were infected off the ship, perhaps doing some activities there,” Kerkhove of WHO said.

“Cases 1 and 2 had travelled in South America, including Argentina, before they boarded the cruise ship on 1 April 2026,” WHO’s alert says. “The extent of passenger contact with local wildlife during the voyage, or prior to boarding in Ushuaia, remains undetermined.”

However, person-to-person transmission cannot fully be ruled out, even though it’s exceedingly rare with hantavirus. “We do believe that there may be some human-to-human transmission that’s happening among the really close contacts,” Kerkhove said, citing the deceased husband and wife and some of the ill passengers who shared cabins.

Should travellers be concerned about hantavirus continuing to spread?

“Person-to-person transmission of hantavirus is very rare, and known to occur with just one strain,” says Dr. Daniel Kuritzkes, senior physician in the Division of Infectious Diseases at Mass General Brigham.

That strain, called the Andes hantavirus, is endemic to both Chile and Argentina. Although the vessel originally departed from Argentina, “it’s too soon to draw conclusions from what happened on board this ship,” McWilliams says.

WHO technical expert Anaïs Legand says what makes this outbreak “most unusual” is the transmission of the virus between people on a boat, but it is still a rare phenomenon and isn’t likely to continue off the ship.

Additionally, close contact, rather than casual contact, appears to be an important factor in human transmission of the virus, Kuritzkes notes, citing a study that found respiratory droplets – rather than aerosols – are likely responsible for rare cases of human transmission. “The significance being that droplets settle quickly and are less likely to result in infection of people who just happen to be in the same room,” Kuritzkes says.

Overall, experts expect the current situation to remain isolated to the cruise ship. In past instances of person-to-person spread of hantavirus, quarantine promptly led to the control of the outbreak, according to Kuritzkes. “There is a very low likelihood that the current outbreak will lead to a more generalised epidemic,” he says.

Should travellers take any special precautions if they’re visiting Argentina or South America?

Travellers shouldn’t feel the need to cancel trips to South America or take any measures beyond normal safety precautions. “There’s no reason for people to be concerned about travel to Argentina, but people should be cautious about visiting places where rodents might be nesting,” says Kuritzkes. “People staying at typical hotels, eating in restaurants, and visiting typical tourist attractions most likely have no or minimal risk of acquiring hantavirus.”