Eighteen American passengers have been airlifted home to the United States after a deadly hantavirus outbreak aboard an Antarctic expedition cruise ship, with federal health officials placing two of them in biocontainment units as a precaution.
The U.S. State Department flew the passengers out of Tenerife, a Spanish island, on May 10. According to the Health and Human Services X account, the two patients in biocontainment were isolated "out of an abundance of caution." One tested positive for hantavirus, while the other developed mild symptoms. The remaining 16 Americans are being treated at an ASPR Regional Emerging Special Pathogen Treatment Center in Omaha, Nebraska. Two more are at a similar facility in Atlanta, Georgia.
The outbreak traces back to the MV Hondius, a Dutch-flagged vessel that departed southern Argentina on April 1 carrying roughly 150 passengers and crew. It was an expedition cruise through the Atlantic Ocean. Eleven days into the voyage, a 70-year-old man died after developing fever, headaches, and abdominal pain. More passengers fell ill, and the World Health Organization eventually identified the ship as the site of a hantavirus outbreak. By May 12, the WHO had confirmed 11 hantavirus cases linked to the vessel and three deaths: a Dutch married couple and a German national.
Investigators believe the rare Andes strain of hantavirus spread among passengers in the ship's close quarters. All remaining passengers have since disembarked and are being returned to their home countries, according to Oceanwide Expeditions, the ship's operator.
The WHO acknowledged that more cases are likely given how quickly the virus can spread in confined spaces and the length of its incubation period. "We expect more cases given the dynamics of spread on a ship and the virus' incubation period," the agency posted on X on May 12. "At the moment, there is no sign that we are seeing the start of a larger outbreak."
Public concern about another pandemic similar to COVID-19 has followed the repatriation efforts, but experts say those fears are out of proportion to the actual risk. Lina Moses, an epidemiologist and disease ecologist at Tulane University's Celia Scott Weatherhead School of Public Health and Tropical Medicine, told Healthline she believes the response has been effective. "I think we're actually in very good shape," Moses said. She specializes in rodent-borne diseases and noted that rising case counts should be read as a sign of proper surveillance, not spiraling spread. "It's not surprising we're starting to see more suspected cases. That means that the process is working right. They are monitoring people effectively and identifying people as they become ill," she said.
Hantavirus is typically transmitted through contact with infected rodents or their droppings. The Andes strain, found primarily in South America, is one of the few hantavirus variants known to spread from person to person, which has made the cruise ship setting particularly concerning for investigators. Still, the WHO has maintained that broader public risk remains low, and no evidence has emerged of transmission beyond the ship's passengers and crew.
