What to know about hantavirus amid suspected cluster aboard cruise ship

A suspected hantavirus cluster aboard a cruise ship has raised concerns about the rare, rodent-borne disease.

Eight cases are currently being reported by the World Health Organization (WHO), including five laboratory-confirmed cases and three suspected cases. Three deaths have resulted from those eight cases.

There appears to be at least two confirmed cases and three suspected cases that may not to be part of the WHO official count.

Here's what you need to know about hantavirus including what it is, how it spreads, how it's treated and if there are any prevention methods:

What is hantavirus?

Hantaviruses are a family of viruses that can cause serious illnesses and death, according to the Centers for Disease Control and Prevention (CDC).

The viruses cause two syndromes: hantavirus pulmonary syndrome (HPS) and hemorrhagic fever with renal syndrome (HFRS). HPS is mostly found in the Western Hemisphere, including the U.S., and HFRS is mostly found in Europe and Asia.

Surveillance for hantavirus in the U.S. began in 1993 during an outbreak in the Four Corners region, where Arizona, Colorado, New Mexico and Utah meet, the CDC said. Between 1993 and the end of 2023, 890 cases of hantavirus disease have been reported in the U.S., according to the CDC.

Hantavirus became more widely known after being identified as the cause of death of the wife of actor Gene Hackman after the couple was found dead at their New Mexico home in February 2025.

How does hantavirus spread?

Hantaviruses are usually spread through rodents, including rats and mice, mostly from exposure to urine, droppings or saliva. Although the viruses can spread through a rodent bite or scratch, such infection is rare, the CDC says.

Hantaviruses may also spread from person to person, but that also is rare and only suspected for one subtype from South America, according to the WHO.

The strain of hantavirus in the suspected cluster has been determined to be the Andes virus, which historically has been shown to potentially transmit between people.

Dr. Jeanne Marrazzo, CEO of the Infectious Diseases Society of America, said during a press conference on Thursday that she believes the spread in the suspected cluster is through "respiratory material."

“About human to human transition, again, theoretically, both potential methods. People could have infected material on their hands. They could potentially transmit it that way," she said. "But we believe, at least from the outbreak in Argentina that occurred and was written up in the New England Journal several years ago, pre-pandemic, that it probably is transmitted through respiratory material, whether it's airborne, whether it's droplet, we don't really know."

What are the hantavirus symptoms?

HPS symptoms typically appear from one to eight weeks after contact with the virus, with early signs including fever, fatigue and muscle aches, according to the CDC. Half of HPS patients will experience headaches, chills, dizziness, nausea, vomiting, diarrhea and abdominal pain.

The CDC says that between four and 10 days after the initial phase of illness, the late symptoms will appear, including coughing, shortness of breath and tightness in the chest as the lungs fill with fluid.

About 38% of people who develop HPS respiratory symptoms may die from the disease, according to the CDC.

Symptoms of HFRS usually develop one to two weeks after exposure and typically include intense headaches, fever, chills, back pain, abdominal pain, nausea and vomiting, the CDC says.

Later symptoms may include low blood pressure, lack of blood flow, internal bleeding and acute kidney failure. Depending on the virus causing the infection, fatality among infected humans can range from less than 1% to as high as 15%, the CDC says.

What hantavirus treatments are available?

No specific treatment is available for hantavirus infection, with the CDC recommending patients receive supportive care such as rest, hydration and treatment of symptoms.

Because HPS can cause breathing difficulties, patients may need breathing support, such as intubation, the CDC says.

HFRS can disrupt kidney function and infected patients may need dialysis to remove toxins from the blood, according to the CDC.

Is there a vaccine?

There is no vaccine that protects against hantavirus.

The CDC recommends that people avoid contact with rodent urine, droppings, saliva and nesting materials. If mice or rats are found or around the home, the CDC says it's important to clean up after them safely.