Three passengers have died and three other people are being treated amid a "public health event" involving suspected hantavirus infections on a cruise ship in the Atlantic Ocean, health officials said.

Of the six people sickened, hantavirus was confirmed in one case and is suspected in five others, the World Health Organization said in a statement Sunday.

Two of the people who died were identified as a married couple, a 70-year-old man declared dead on arrival in St. Helena, and a 69-year-old woman who collapsed at Johannesburg’s international airport while attempting to fly to the pair’s home country of the Netherlands. She died at a health facility, South African Health Ministry spokesperson Foster Mohale said.

The husband's remains were in St. Helena, an island midway between South America and Africa, awaiting repatriation to the Netherlands, Mohale said.

Details on the third death were not immediately available.

The vessel had an estimated 150 passengers as it traveled from Ushuaia, Argentina, with multiple stops including mainland Antarctica, the Falklands, South Georgia, Nightingale Island, Tristan, St. Helena, Ascension, and Cape Verde, Mohale said. The ship left Ushuaia about three weeks ago.

A passenger from the U.K. who became ill while the cruise ship was traveling from St. Helena to Ascension Island was being treated at a hospital in South Africa, Mohale said. His lab results tested positive for hantavirus, Mohale said.

The WHO and the cruise operator, Oceanwide Expeditions, said one person was in intensive care in South Africa.

The health agency said it is helping the ship's operators launch a medical evacuation of the two other symptomatic people, though it was not immediately clear whether that had happened.

The cruise ship Hondius remains off Cape Verde, an African country in the Atlantic Ocean. Authorities there have visited the ship to assess the conditions of the symptomatic people but have not authorized them to disembark, its operator, Oceanwise Expeditions, said in a statement.

The two symptomatic people who remain on board are crew members, the Netherlands-based operator said.

"The priority of Oceanwide Expeditions is to ensure that the two symptomatic individuals on board receive adequate and expedited medical care," the company said.

The World Health Organization said medical care was being provided to those on board who need it while multiple investigations have been launched and sequencing of the virus was underway.

According to the U.S. Centers for Disease Control and Prevention, hantavirus infections can cause hantavirus pulmonary syndrome, which affects the lungs and kills more than a third of its patients in the United States; and hemorrhagic fever with renal syndrome, a group similar illnesses that affects the kidneys.

Hantaviruses are spread by contact with rodents or their urine, droppings, and saliva, the CDC said, and do not often spread via person-to-person contact. Symptoms include fever, breathing difficulty, fatigue, and nausea, the CDC said.

The World Heath Organization said, "While rare, hantavirus may spread between people, and can lead to severe respiratory illness and requires careful patient monitoring, support and response."

In February 2025, Betsy Arakawa, the wife of legendary Hollywood actor Gene Hackman died of hantavirus pulmonary syndrome. Hackman, 95 and in poor health, died from heart disease and Alzheimer’s disease, likely about a week after his wife, authorities said. The couple’s bodies were found in their home in New Mexico, authorities said.

CORRECTION (May 3, 2026, 8:35 p.m. ET): A previous version of this article mischaracterized one of the victims. A U.K. man with a confirmed case of hantavirus was being treated in South Africa. He is not among the three dead.