3 dead after suspected hantavirus cases on cruise ship, WHO says

Three people who were aboard a cruise ship in the Atlantic Ocean have died of suspected infections of hantavirus, a rodent-borne virus that can cause fatal respiratory illness, the World Health Organization said.

"To date, one case of hantavirus infection has been laboratory confirmed, and there are five additional suspected cases," the organization announced May 3 on X. "Of the six affected individuals, three have died and one is currently in intensive care in South Africa."

In a statement provided to USA TODAY, Netherlands-based expedition cruise operator Oceanwide Expeditions said it was addressing a "serious medical situation" on the MV Hondius. The ship was en route from Argentina to Cape Verde, an island nation off Africa's west coast.

Investigations are ongoing, according to WHO. Here's what we know now.

What happened aboard MV Hondius?

On April 11, a Dutch guest died aboard the ship and was later disembarked on St. Helena, an island in the South Atlantic Ocean, Oceanwide said in an update May 4. The cause of death could not be determined onboard.

His wife, who accompanied the repatriation, became "unwell" during their return trip and also later died. Both were Dutch nationals.

"At this time, it has not been confirmed that these two deaths are connected to the current medical situation on board," the company said.

A hantavirus variant was identified, however, in a British passenger who "became seriously ill" and was medically evacuated to South Africa on April 27, the company said. That passenger is stable but remains in critical condition in Johannesburg.

On May 2, a German passenger died aboard the vessel, though the cause was not yet known.

Two crew members, of British and Dutch nationality, currently have acute respiratory symptoms – one mild case and one more severe. The cruise company was working with international and local authorities on next steps.

"Hantavirus has not currently been confirmed in the two persons still on board who require medical care," Oceanwide said. "Nor has it been established that the virus is connected to the three deaths associated with this voyage. The exact cause and any possible connection are being investigated."

One hundred forty-nine people are still aboard, including passengers from the United States, according to Oceanwide.

Jake Rosmarin, a passenger on the ship, appeared to fight back tears in a video shared on Instagram May 4. "There’s a lot of uncertainty, and that’s the hardest part," he said. "All we want right now is to feel safe, to have clarity and to get home."

Oceanwide did not immediately respond to a separate request for comment on the video. But the cruise company noted in its May 4 update that stringent precautionary measures are being taken, including isolation measures, hygiene protocols and medical monitoring.

How is hantavirus transmitted?

The Centers for Disease Control and Prevention describes hantavirus as a family of viruses that can cause serious illnesses and death. The agency said hantavirus is primarily spread by rodents through exposure to their urine, droppings or saliva, and less commonly through a scratch or bite.

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

What happens when you have hantavirus?

The CDC said hantaviruses can cause two syndromes: hantavirus pulmonary syndrome (HPS), which affects the lungs, or hemorrhagic fever with renal syndrome (HFRS), which strikes the kidneys.

HPS symptoms can include fatigue, fever, muscle aches, headaches, dizziness, chills and abdominal problems, followed later by coughing, shortness of breath and possible “tightness in the chest as the lungs fill with fluid,” according to the CDC.

The CDC said HFRS symptoms may include intense headaches, back and abdominal pain, fever, chills, nausea, blurred vision, a flushed face, eye redness or inflammation, and a rash, followed later by low blood pressure, acute shock from reduced blood flow, internal bleeding and "acute kidney failure, which can cause severe fluid overload."

The World Health Organization did not specify the type of hantavirus or syndrome in the cruise ship outbreak but did mention respiratory risks.

The CDC said HPS can be fatal for 38% of people who develop respiratory symptoms. According to the CDC, the fatality rate for HFRS ranges from fewer than 1% to as high as 15%, depending on the specific virus.

This story was updated to add new information.

Contributing: Charles Ventura, USA TODAY; Reuters