International health officials are tracing passengers from the cruise ship MV Hondius after a rare outbreak of the Andes strain of hantavirus left three people dead and several others infected. The virus, unlike most hantavirus variants, can spread between humans through close contact. Investigators in Argentina are now conducting rodent testing and tracing the travelers’ movements to determine where the outbreak began.
Authorities in at least 12 countries — including the United States, the United Kingdom, Canada, Singapore, Switzerland, and Germany — are monitoring travelers who left the ship before the illness was identified. U.S. officials confirmed that passengers in Georgia, Virginia, Arizona, and California are being observed, though none have reported symptoms.
Oceanwide Expeditions said in a statement that the company “continues to manage an ongoing medical situation on board m/v Hondius” and that their “cooperation continues with local and international authorities, including the WHO, the RIVM, relevant embassies, and the Dutch Ministry of Foreign Affairs.”
The outbreak began during a bird-watching expedition linked to South America. The World Health Organization said the first victims, a Dutch couple, had recently traveled through Argentina, Chile, and Uruguay, including areas where rodents known to carry the Andes virus are found. The husband died aboard the ship on April 11, but doctors initially did not suspect hantavirus because his symptoms resembled other respiratory illnesses. His wife later disembarked on the remote Atlantic island of St. Helena and became severely ill while traveling through South Africa. She briefly boarded a KLM flight in Johannesburg before being removed because of her condition and later died there.
Subsequently, a British passenger evacuated from the ship to South Africa became the first confirmed hantavirus case on May 2 and remains hospitalized, though officials say his condition has improved. Another passenger later tested positive in Switzerland, while several additional suspected cases are under investigation in Europe and Asia.
Dutch officials are also testing a flight attendant who may have been exposed after contact with the infected Dutch woman. KLM Royal Dutch Airlines said that a Dutch woman who died after contracting hantavirus was “briefly” on board a flight from Johannesburg to Amsterdam and was removed from the plane before takeoff. It is not clear if the flight attendant was on this same flight. KLM said in a statement it does not comment on individual cases “for privacy reasons.” If confirmed, it would mark the first known infection tied to someone who was not aboard the ship.
The WHO says the overall public risk remains low because the Andes virus does not spread easily like COVID-19 or influenza. Officials noted that transmission typically requires prolonged close contact, especially among partners, family members, or caregivers. About 30 passengers left the ship in St. Helena on April 24 before health authorities realized hantavirus was involved, prompting an international effort to locate and monitor them. Some governments have advised exposed travelers to isolate for up to 45 days because symptoms can appear anywhere from one to eight weeks after exposure.
Dr. Jay Bhattacharya from the CDC said in a statement: “Our hearts go out to the passengers aboard the cruise ship M/V Hondius and their families during this difficult time. Our CDC team began coordinating with domestic and international partners as soon as we were notified of a hantavirus situation. We understand that people are concerned and looking for information and that is why we provided clear, written health guidance to the American passengers through the State Department. The safety and health of the affected American travelers is our number one goal. Hantavirus is not spread by people without symptoms, transmission requires close contact, and the risk to the American public is very low. CDC has the world’s leading experts on hantavirus and is lending its technical expertise when coordinating with interagency partners, state health offices, and international authorities on response and repatriation planning. We will be monitoring the health status and preparing medical support for all of the American passengers on the cruise. CDC will continue to update as more information becomes available and remains committed to protecting the health and safety of the American public.”
Nearly 150 passengers and crew members remain aboard the Hondius as it sails toward Spain’s Canary Islands. Crew members are disinfecting cabins and isolating anyone who develops symptoms. So far, no additional illnesses have been reported among those still on the vessel.
The CDC said the State Department is coordinating with global health agencies and directly contacting affected passengers. Officials stressed there is no sign of a wider epidemic, and experts say hantavirus infections are extremely rare. According to CDC data, fewer than 900 confirmed cases were reported in the U.S. between 1993 and 2023.
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