WHO Confirms Five Hantavirus Cases on Atlantic Cruise Ship

The World Health Organization confirmed five cases of hantavirus linked to the MV Hondius cruise ship in the Atlantic Ocean, with three deaths reported so far and three additional suspected cases. Officials said at a press briefing on Thursday that the public health risk remains low despite the possibility of more cases due to the virus's long incubation period.

The ship, which was sailing from Cape Verde toward Tenerife in Spain's Canary Islands, carried 147 passengers and crew from 23 nationalities. Tedros Adhanom Ghebreyesus told reporters the agency had been notified by the UK of a cluster of passengers with severe respiratory illness.

While describing the incident as serious, he emphasized that the overall threat to wider public health is low. The strain identified is the Andes virus, the only hantavirus known to be capable of limited human-to-human transmission.

The first death occurred in a man who developed symptoms on April 6 and died five days later. No samples were taken at the time because symptoms resembled those of other viruses. His wife became the second victim after going ashore in Saint Helena, where she became symptomatic and died on April 25.

A third woman developed symptoms on April 25 and died seven days later. Before boarding the ship the first two victims had traveled in Chile, Argentina and Uruguay on a bird-watching trip that included sites known to harbor rats carrying hantavirus.

Argentine authorities are investigating the couple's movements. The virus is typically transmitted to humans through contact with infected rodents, their urine, droppings or saliva. The Andes strain has been found in Latin America and is associated with limited person-to-person spread during prolonged close interactions such as those among household members, intimate partners or healthcare workers.

Previous clusters have shown transmission mainly during the early symptomatic phase rather than before symptoms appear. Experts noted the median incubation period is 18 days, with a range of seven to 39 days. This slower progression compared with respiratory viruses like SARS-CoV-2 gives public health officials more time to identify cases and implement isolation measures.

The disease can cause severe hantavirus cardiopulmonary syndrome with a case fatality rate of 35 to 40 percent, which tends to limit further spread as patients become too ill to travel or interact widely. The CDC said in a statement it was closely monitoring the situation as the State Department coordinates a whole-of-government response for U.S. passengers onboard.

The public health risk to Americans is currently extremely low, according to the statement. Oceanwide Expeditions, the cruise ship operator, reported there are 17 Americans currently aboard the vessel.

The WHO has informed 12 countries whose nationals disembarked in Saint Helena before the outbreak was fully recognized. Those countries are Britain, Canada, Denmark, Germany, the Netherlands, New Zealand, Saint Kitts and Nevis, Singapore, Sweden, Switzerland, Turkiye and the United States.

Argentina will send 2,500 diagnostic kits to laboratories in five countries to aid testing. Some American passengers had disembarked when the ship stopped at St. Helena prior to recognition of the outbreak. Two Canadian passengers who left the ship are now in Ontario.

Officials have not disclosed detailed plans for monitoring all potentially exposed individuals who left the vessel earlier. Investigations into the precise origin of the outbreak aboard the ship are still under way.

“This is not coronavirus, this is a very different virus... That episode began with a single rodent-to-human spillover and produced 34 confirmed cases before public health interventions reduced the reproductive number below one and ended the chain of transmission. Experts said standard isolation and quarantine measures proved sufficient even in that worst documented scenario. On the Hondius the current attack rate stands at roughly five percent after five weeks, far lower than the rapid spread seen with COVID-19 aboard the Diamond Princess in early 2020. Infectious-disease specialists described the cruise ship incident as a one-off situation that requires careful contact tracing across multiple countries but does not signal potential for large-scale epidemic spread. The retirement of the top official responsible for the CDC's Vessel Sanitation Program was announced internally on Wednesday. The departure follows a turbulent period for the division that included temporary layoffs of full-time employees in April 2025, later reversed by administration officials. The program continues to operate as the agency monitors the hantavirus situation.”