CANARY ISLANDS — The cruise ship MV Hondius was held off Spain's port of Tenerife in the Canary Islands on May 6, 2026, as epidemiologists monitored more than 140 passengers and crewmembers for hantavirus symptoms. The World Health Organization declared the cases an outbreak on May 4, 2026, two days after hantavirus was first identified as the cause of illness in one of the cases.

An elderly Dutch couple boarded the ship carrying a strain of hantavirus transmitted between humans after contracting it in Argentina in April 2026. In early April, a 70-year-old Dutch man developed a feverish illness during a voyage from Argentina to Antarctica and died less than a week later aboard the vessel. His wife developed symptoms after disembarking at St. Helena and died in South Africa. A German woman also became sick and died, and another passenger on the ship later died.

Three passengers were evacuated to the Netherlands for medical care, and 23 passengers left the ship on April 23 after being exposed to the virus, according to a passenger aboard. Hantavirus has a mortality rate of up to 40%, and symptoms can take up to eight weeks to appear. Most passengers remain on board, answering questions from health workers and awaiting symptom onset, with access to food, hot drinks and fresh air on the outer decks. Meals can be delivered directly to cabins.

About 24 Americans were on the ship, including about seven who disembarked last month and 17 who remained on board. Late Friday, the U.S. Centers for Disease Control and Prevention deployed a team to the Canary Islands to meet the Americans on board. The agency plans to send a second team to Offutt Air Force Base in Nebraska as part of a plan to evacuate American passengers to a University of Nebraska quarantine center for evaluation and monitoring. The CDC also issued its first health alert to U.S. doctors advising them of the possibility of imported cases.

At a Saturday briefing, CDC officials pledged to be transparent in updating the public but said media could not cite speakers by name under rules set by aides to Health Secretary Robert F. Kennedy Jr. Officials did not answer whether American passengers could leave the University of Nebraska medical facility at will.

President Donald Trump said, "We seem to have things under very good control." "The CDC is not even a player. I've never seen that before," said Lawrence Gostin, an international public health expert at Georgetown University. For decades, the CDC partnered with the World Health Organization in such situations, providing staff and expertise to help investigate outbreaks.

"The hantavirus outbreak is a sentinel event that speaks to how well the country is prepared for a disease threat. And right now, I'm very sorry to say that we are not prepared," said Dr. Jeanne Marrazzo, chief executive officer of the Infectious Diseases Society of America.