Health authorities are investigating a suspected outbreak of hantavirus aboard the Dutch-flagged cruise ship MV Hondius, currently moored off the coast of Cape Verde in the Atlantic Ocean. The vessel, carrying 147 passengers and crew, has reported seven confirmed or suspected cases of hantavirus infection, including three fatalities. Two of the cases have been laboratory-confirmed, while the remaining five are suspected. The World Health Organization (WHO) has indicated the possibility of human-to-human transmission among close contacts, a rare occurrence for this virus typically spread through contact with infected rodents.

The MV Hondius departed Ushuaia, Argentina, in late March and made stops in Antarctica and several remote islands before arriving near Praia, Cape Verde, on Sunday. Local health officials denied the vessel permission to dock due to public health concerns. The ship primarily includes passengers from Britain, the United States, and Spain.

According to WHO officials, the initial cases involved a Dutch couple who boarded the ship in Argentina, where the Andes variant of hantavirus is endemic. This strain has been documented to spread in limited instances through close human contact, such as between family members. The virus is generally transmitted to humans via exposure to rodent urine, droppings, or saliva, but the current outbreak raises concerns about person-to-person spread within shared cabins or close quarters. Other passengers may have also been exposed during onshore bird-watching trips to locations with rodent presence.

A German passenger has also died, and a British national was evacuated to South Africa for intensive care. Two crew members remain in urgent medical condition. Dutch authorities are coordinating the medical evacuation of at least three individuals to the Netherlands, though the timing and disembarkment plans for the remaining passengers are still under discussion with the ship operator, Oceanwide Expeditions. Spain’s health ministry stated it does not see a need for the ship to stop in the Canary Islands if all sick individuals are treated in Cape Verde, barring new cases.

Maria Van Kerkhove, WHO’s director of epidemic and pandemic preparedness and prevention, emphasized that while the organization is working under the assumption of limited human-to-human transmission, the full epidemiological picture is still emerging. The WHO stressed that the overall risk to the general public remains low. Hantavirus pulmonary syndrome, caused by infection with hantavirus variants including the Andes strain, can lead to severe respiratory illness with symptoms such as fever, muscle aches, coughing, and difficulty breathing. There are currently no vaccines or antiviral treatments for the condition, and care is supportive.

Investigations and laboratory testing are ongoing, with the WHO and Spanish health authorities preparing for a comprehensive epidemiological review once the ship reaches territorial waters. Officials have confirmed that there were no rats detected onboard the vessel, suggesting that rodent exposure aboard the ship is unlikely. The outbreak and the possibility of rare human-to-human transmission highlight the challenges in managing hantavirus infections in confined settings like cruise ships.