Three people who were on board a Netherlands-based cruise ship in the Atlantic have died during a suspected outbreak of the hantavirus, authorities say. The virus is a rare infection transmitted to humans by rodents.

On Monday, the World Health Organization (WHO) said the risk posed by the hantavirus to the wider public remained low despite the deaths on the MV Hondius cruise ship.

So what is the hantavirus, how does it spread and should people be worried?

Who caught the hantavirus on the MV Hondius?

The MV Hondius was sailing from Ushuaia, Argentina, to Cape Verde. Currently anchored off Cape Verde, the ship was considering ‌sailing to Las Palmas or Tenerife ‌for disembarkation, Reuters reported on Monday.

Three people who were on the ship have been confirmed dead, although they are all only suspected of being infected with hantavirus. Three other people are ill. Of those, only one – a British national – has been confirmed as infected with the virus.

In a statement on Sunday, the WHO said one hantavirus case had been confirmed and at least five other passengers were suspected of being infected.

“Of the six affected individuals, three have died, and one is currently in intensive care in South Africa,” the WHO said.

“Detailed investigations are ongoing, including further laboratory testing and epidemiological investigations. Medical care and support are being provided to passengers and crew. Sequencing of the virus is also ongoing.”

The WHO added that it was “facilitating coordination” between countries to evacuate the two other passengers showing symptoms.

Earlier on Sunday, South Africa’s National Department of Health reported the outbreak of a “severe acute respiratory illness” that it said had killed at least two people while a third person was in intensive care in Johannesburg, according to the AFP news agency.

Department spokesperson Foster Mohale confirmed the patient being treated in Johannesburg had tested positive for the hantavirus.

Mohale told reporters that authorities had not yet confirmed the nationalities of the deceased. The person in intensive care was reported by AFP and media in the United Kingdom to be a 69-year-old Briton.

A 70-year-old was the first to develop symptoms. He died on the ship, and his body was transferred to the island of Saint Helena, a British territory in the South Atlantic, the spokesman said.

The patient’s 69-year-old wife also fell sick and was evacuated to South Africa but died in a Johannesburg hospital, he added.

What is the hantavirus?

The hantavirus is a family of viruses that cause two illnesses. One is known as hantavirus pulmonary syndrome and primarily affects the lungs. The other, haemorrhagic fever with renal syndrome (HFRS), attacks the kidneys.

The first receives the most attention because it has a fatality rate of about 40 percent.

The death rate for the second type varies from 1 percent to 15 percent of patients, according to the US Centers for Disease Control and Prevention (CDC).

Authorities have not confirmed which of these two illnesses has spread on the cruise ship, but it is believed to be the pulmonary hantavirus, international media have reported.

The virus is most commonly spread by infected rodents, which can carry it in their urine, saliva or droppings.

When these materials dry out and become airborne, humans can become infected by inhaling the contaminated particles.

Hantaviruses can spread directly between people although this is rare, according to the WHO.

The name of the virus is derived from the Hantan River area of South Korea, where the infection was identified in the 1970s, according to The Lancet medical journal.

Studies indicated hantaviruses have been around for centuries with outbreaks documented in Asia and Europe.

It wasn’t until the early 1990s that a previously unknown group of hantaviruses emerged in the southwestern United States as the cause of an acute respiratory disease now known as hantavirus pulmonary syndrome.

The CDC began tracking the virus after a 1993 outbreak in the Four Corners region, where the states of Arizona, Colorado, New Mexico and Utah meet.

Where is the hantavirus commonly found?

Hantavirus pulmonary syndrome is most commonly found in North and South America.

According to the Canadian government, about 200 cases of hantavirus pulmonary illness occur each year worldwide.

Concert pianist Betsy Arakawa, wife of actor Gene Hackman, died from hantavirus pulmonary syndrome in New Mexico in 2025, according to autopsy results.

In the Eastern Hemisphere, haemorrhagic fever and kidney failure associated with HFRS have been more commonly reported.

What are the symptoms?

Hantavirus pulmonary syndrome usually begins with flu-like symptoms, such as fatigue and fever, between one and eight weeks after exposure, according to the CDC.

Four to 10 days later, coughing, shortness of breath and fluid in the lungs appear.

Diagnosis in the first 72 hours of infection is difficult, the CDC said, and symptoms can easily be mistaken for the flu.

HFRS usually develops within a week or two after exposure.

How is the hantavirus treated and prevented?

There is no specific therapy for a hantavirus infection, so treatment focuses on supportive care, including rest and fluids. In the case of hantavirus pulmonary syndrome, patients may require breathing support, such as a ventilator.

Experts said exposure to the hantavirus can be minimised by deterring and eliminating rodents from areas where people are. Avoid vacuuming or sweeping dried droppings, which can aerosolise the virus.

How risky is the hantavirus for the wider public?

The WHO said the hantavirus poses a low risk to the wider public.

“The risk to the wider public remains low. There is no need for panic or travel restrictions,” the WHO’s regional director for Europe, Dr Hans Henri P Kluge, said in a statement.