What is the hantavirus that has been confirmed on an Atlantic cruise ship?

Three people have died after a suspected hantavirus outbreak on a cruise ship sailing in the Atlantic Ocean, according to the World Health Organization (WHO).

One hantavirus case has been confirmed, with five more suspected cases under investigation, it says.

The WHO told the BBC that "detailed investigations" into the suspected hantavirus cases are "ongoing, including further laboratory testing".

The outbreak was reported aboard the MV Hondius cruise ship, which was travelling from Argentina to Cape Verde.

Here's what we know about hantavirus.

Hantavirus refers to a strain of viruses carried by rodents, primarily transmitted to humans through inhalation of airborne particles from dried rodent droppings.

Infections typically occur when the virus becomes airborne from a rodent's urine, droppings, or saliva, according to the US Centers for Disease Control and Prevention (CDC).

Though rare, it can also spread through rodent bites or scratches.

The virus can cause two severe illnesses. The first, Hantavirus Pulmonary Syndrome (HPS), often starts with fatigue, fever, and muscle aches, followed by headaches, dizziness, chills, and abdominal issues. If respiratory symptoms develop, the mortality rate is approximately 38%, according to the CDC.

The second illness, Haemorrhagic Fever with Renal syndrome (HFRS), is more severe and primarily affects the kidneys. Later symptoms can include low blood pressure, internal bleeding, and acute kidney failure.

There are an estimated 150,000 cases of HFRS worldwide each year, primarily in Europe and Asia, according to a report from the National Institutes of Health. More than half of the cases typically occur in China.

The latest data from the US shows that from between 1993, when surveillance of hantavirus began, until 2023, there were 890 cases in the country.

However, Seoul virus, one of the main strains of hantavirus that is carried by Norway rats (also known as the brown rat), is found worldwide, including in the US.

There is no specific treatment for hantavirus infections.

The CDC recommends supportive care to treat symptoms that could include oxygen therapy, mechanical ventilation, antiviral medications and even dialysis.

Patients with severe symptoms may need to be admitted to hospitals in intensive care units. In severe cases, some may need to be intubated.

The CDC recommends eliminating contact with rodents in homes or workplaces to reduce exposure to the virus.

The agency also recommends sealing entry points in basements or attics where rodents may enter homes.

Wearing protective gear is also suggested when cleaning up rodent droppings to avoid inhaling contaminated air.

In February 2025, Betsy Arakawa, the wife of Oscar-winning actor Gene Hackman, died from a respiratory illness linked to hantavirus.