Outbreak kills 3 on cruise ship. What to know about hantavirus in California

An outbreak of hantavirus, a disease also found in California, aboard a cruise ship has killed three passengers and sickened others.

The outbreak took place on the MV Hondius, a Dutch cruise ship that set out from Argentina to cross the Atlantic Ocean about a month ago, BBC News said. It is now anchored off of Africa.

About 150 people from 23 nations are on board. The World Health Organization said seven cases of hantavirus have been identified, BBC News reported.

Hantavirus, which is spread by mouse droppings, is also found in California. A Placer County man died of the virus in 2018, The Sacramento Bee reported. But the W.H.O. also said on Tuesday that some of those who had fallen ill on the cruise may have been infected through human-to-human transmission, which is rare, but .

Here’s what to know about hantavirus:

What is hantavirus?

As its name suggests, hantavirus is part of a family of viruses that spread to humans through exposure to infected urine, droppings or saliva from rodents, The Journal of the American Medical Association wrote.

The disease can lead to respiratory failure and death, the association said.

Hantavirus is found worldwide, the U.S. Centers for Disease Control and Prevention said. In the Western Hemisphere, it can cause respiratory problems and in Europe and Asia it can cause hemorrhagic fever with kidney damage.

The virus causing hantavirus was discovered in 1978, according to the National Institutes of Health. It’s named after the Hantan River in South Korea, where the rodents with the disease were found.

The virus is also believed to be behind an outbreak among U.S. soldiers during the Korean War, the NIH said.

How common is hantavirus?

Hantavirus is a “fairly rare” disease in humans, the American Lung Association said.

There have been about 890 cases of hantavirus in the United States since tracking began in 1993, the CDC said. Most U.S. cases have occurred in California, Washington, Arizona, New Mexico and Colorado.

Who is at risk for hantavirus?

People who are exposed to rodent nests, urine and droppings are most at risk of developing hantavirus, the Mayo Clinic said.

Common sites for exposure include farm buildings, infrequently used buildings, such as storage sheds, campers or seasonal cabins, camp sites or hiking shelters, attics or basements, and construction sites, the clinic said.

Activities such as opening and cleaning long unused buildings, cleaning up rodent nests or droppings without appropriate precautions, and working in a field that increases exposure to rodents, such as construction, utility work, pest control and farming, also can up the risks.

What are the symptoms of hantavirus?

Early symptoms of hantavirus pulmonary syndrome, the most common infection in the United States, include fatigue, fever and muscle aches, especially in the large muscle groups like the thighs, hips, back, and sometimes shoulders, the CDC said.

About half of those with hantavirus also suffer headaches, dizziness, chills or abdominal problems, like nausea, vomiting, diarrhea, and abdominal pain, the agency said.

Early symptoms normally occur within one to eight weeks of exposure.

After about four to 10 days, symptoms like coughing and shortness of breath occur as the lungs fill with fluid, the CDC said. About 38% of those who develop respiratory symptoms die.

When should you see a doctor about hantavirus?

The South Dakota Department of Health advises you to see a doctor immediately if you have been around rodents and develop fever, deep muscle aches and severe shortness of breath.

Tell your physician you have been exposed to rodents so they can check for hantavirus. A blood test can reveal if you are producing hantavirus antibodies.

How does hantavirus spread?

Hantavirus spreads chiefly when people inhale air contaminated with the virus, the California Department of Public Health said.

That happens mainly when dried mouse urine, saliva or droppings are stirred up, the department said.

“The chances of this happening increase when opening or cleaning buildings in rural areas that have been closed for the winter where deer mice have entered, or for people working, playing, or living in closed spaces where mice are present,” the department said.

The virus also can be spread by touching contaminated objects and then touching the nose or mouth. Bites or scratches from an infected rodent or eating food contaminated with hantavirus, are other forms of exposure, Florida Health said.

How can you prevent hantavirus?

First off, keep wild rodents, especially mice, out of your home, workplace, cabin, shed, car, camper, or other closed space, the California Department of Public Health advised.

If you find signs of mice or other rodents, clean up immediately, while wearing gloves, by spraying with bleach solution or disinfectant and wiping up. If you find live or dead mice, droppings or urine, do not sweep or vacuum, which can stir up contaminated materials.

How do you treat hantavirus?

There’s no specific treatment for hantavirus, but people with advanced respiratory symptoms may need to be hospitalized for intensive care with intubation and ventilation, the Mayo Clinic said.

How can you tell hantavirus from other illnesses?

Early hantavirus symptoms can resemble the flu. A blood test is needed to diagnose hantavirus, the CDC said.

This story was originally published May 5, 2026 at 12:38 PM.