On Sunday, the World Health Organization confirmed three individuals are dead and at least three others are sick after a suspected outbreak of hantavirus aboard a cruise ship sailing in the Atlantic Ocean, according to CNN. The MV Hondius, operated by Oceanwide Expeditions, is currently anchored in Praia, Cape Verde, an island nation off the west coast of Africa. 

Oceanwide Expeditions announced in a statement that 149 people, including 17 Americans, remain on board the ship. 

Cape Verde's health minister, Maria da Luz Lima, stated these passengers will not be allowed to disembark. Local health officials have boarded the ship to evaluate two crew members who display symptoms and require immediate medical attention, according to Oceanwide Expeditions. 

It's not clear how long the ship and its passengers will remain off the coast of Praia.

Hantaviruses are a group of viruses that spread to humans through exposure to infected urine, saliva, or droppings of rodents.

Hantavirus symptoms and severity depend on the specific strain of virus causing the infection, but hantavirus can cause hantavirus pulmonary syndrome. What initially starts off with flu-like symptoms can rapidly worsen into a critical illness, according to the medical journal JAMA Network. 

About one-third of patients with hantavirus pulmonary syndrome who develop respiratory symptoms die.

Person-to-person transmission is rare and has only been identified in the Andes variant of hantavirus. It is primarily found in Chile and Argentina, where the vessel originated.

The MV Hondius set sail from Ushuaia, Argentina, journeying to Antarctica, Ushuaia again, and the British overseas territory of Saint Helena before anchoring in Praia. Along the route, passengers visited some of the world's most remote islands.

Among the six individuals with symptoms, only one case of hantavirus infection has been verified through laboratory testing, while the other five are under suspicion, according to the WHO.

The first victim was a 70-year-old Dutchman who fell ill on the ship and died April 11. The man's 69-year-old wife collapsed at a South African airport attempting to travel home and died at a nearby hospital.

A British national fell ill on April 27 after the ship left Saint Helena. He is now in critical condition at a private medical facility in Johannesburg, South Africa. This was the only confirmed case of hantavirus.

A German national died on board the MV Hondius on May 2, though his cause of death has yet to be confirmed.

A British crew member and a Dutch crew member are currently experiencing acute respiratory symptoms, requiring urgent care. Hantavirus has not been confirmed in their cases.

Still, it is not clear how the infections occurred.

Hans Kluge, WHO's regional director for Europe, declared that "there is no need for panic or travel restrictions."

Between the beginning of surveillance in 1993 and 2023, just 890 confirmed cases of hantavirus disease have been reported in the U.S.

A passenger, travel vlogger Jake Rosmarin, shared a poignant message in an Instagram video, expressing, "What's happening right now is very real for all of us here. We're not just a story. We're not just headlines. We're people, people with families, with lives, with people waiting for us at home. There's a lot of uncertainty, and that's the hardest part."

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