Cruise ship grapples with hantavirus outbreak. Latest on deaths, illnesses

Public health officials are working to contain a hantavirus cluster on a cruise ship in the Atlantic Ocean after three people on board died of suspected infections.

Two cases of the typically rodent-borne illness have now been confirmed among the more than 140 passengers and crew on the MV Hondius ship, according to the World Health Organization and cruise operator Oceanwide Expeditions. Five other cases are suspected.

WHO said the current risk to the rest of the world is low, but it is continuing to monitor the situation and provide updates.

Here's the latest.

What is hantavirus?

A hantavirus is a typically rodent-borne virus that can cause a serious, and sometimes fatal, lung infection in humans, according to the Centers for Disease Control and Prevention.

People typically contract hantavirus from contact with rodent urine, droppings or saliva. It can also spread from person to person, though that is rare, per the Mayo Clinic.

What cruise ship has hantavirus?

The MV Hondius, a cruise ship run by the Netherlands-based expedition cruise operator Oceanwide Expeditions, is experiencing what the WHO calls a hantavirus cluster.

The ship departed from Argentina on April 1 and traveled across the Atlantic, making "multiple stops in remote and ecologically diverse regions" including mainland Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena and Ascension Island, according to WHO.

Where is the cruise ship now?

The ship is currently moored off the coast of Cape Verde, an island nation off Africa's west coast, WHO and Oceanwide Expeditions said.

WHO official Maria Van Kerkhove said during a May 5 news conference that the current plan is to medically evacuate two individuals with suspected infections who are still on board, then the ship will head to the Canary Islands off the coast of Spain. Oceanwide Expeditions said an individual associated with one of the passengers who passed away would also be evacuated.

"We're working with Spanish authorities who will welcome the ship, have said that they will welcome the ship, to do a full investigation – a full epidemiologic investigation, full disinfection of the ship and of course, to assess the risk of the passengers that are actually on board," Kerkhove said.

How is hantavirus transmitted?

Human hantavirus infection is primarily transmitted through contact with the urine, feces or saliva of infected rodents. Although uncommon, limited human-to-human transmission has been reported in previous outbreaks, per the WHO.

Officials believe a husband and wife, Dutch nationals, were infected while they were off the cruise ship, engaging in wildlife expeditions. Others with suspected infections may have come in contact with the virus on islands as well, Kerkhove said.

"However, we do believe that there may be some human-to-human transmission that's happening among the really close contacts – the husband and wife, people who've shared cabins, etcetera," Kerkhove said.

Hantavirus symptoms

Symptoms typically begin two to three weeks after infection, and can include fever, chills, muscle aches, vomiting and diarrhea. In serious cases, it can cause issues with lung and heart function, per the Mayo Clinic.

How many people on cruise are sick from hantavirus?

According to the WHO, seven cases, including two lab-confirmed and five suspected cases of hantavirus, have been identified among those on the ship. The agency said a total of 147 passengers and crew are on board.

The cases include three deaths, one critically ill person and three others reporting mild symptoms.

Here's a summary of the cases, per the WHO and Oceanwide Expeditions:

1. An adult male developed symptoms of fever, headache, and mild diarrhea on April 6 while on board the ship. He developed respiratory symptoms and died on board on April 11. His body was removed to Saint Helena on April 24.
2. An adult female, identified as the wife of the male who died on board on April 11, went ashore to Saint Helena on April 24 with gastrointestinal symptoms. Her symptoms worsened during a flight to Johannesburg, South Africa, on April 25. She died on April 26. The case was confirmed as a hantavirus infection on May 4.
   • Officials said the husband and wife were Dutch nationals and had traveled in South America, including Argentina, before they boarded the cruise ship.
3. An adult male who reported a fever, shortness of breath and signs of pneumonia to the ship's doctor on April 24. After his condition worsened, he was medically evacuated to South Africa on April 27, where he is currently hospitalized in an Intensive Care Unit. Testing confirmed a hantavirus infection on May 2.
4. An adult female whose symptoms began on April 28 and included fever and signs of pneumonia. She died on May 2.
5. An individual who is still on board and being prepared for medical evacuation to the Netherlands for treatment, Kerkhove said.
6. An individual who is still on board and being prepared for medical evacuation to the Netherlands for treatment, Kerkhove said.
7. An individual who reported a mild fever at one point but is currently asymptomatic, Kerkhove said.

Melina Khan is a national trending reporter for USA TODAY. Keep up with her on X @melinakh and Instagram @bymelinakhan.

(This story was updated to add new information.)