What is a hantavirus? Symptoms, treatments, prevention and how it spreads

Disease name: Hantavirus disease

Affected populations: Hantavirus disease is an uncommon but potentially deadly infection caused by a family of viruses called hantaviruses. These viruses are found worldwide and are typically carried and spread by rodents, such as rats and mice. Different types of hantaviruses are associated with specific rodent species, which can carry the viruses without overt signs of illness.

Most hantaviruses cannot spread from person to person, but one type — the Andes virus, found in South America — can do so.

The United States began tracking hantavirus disease in 1993, and between then and 2023, 890 cases were reported within the country. The states with the highest number of reported cases include Washington, California, Arizona, Colorado and New Mexico. An imported case of Andes virus was reported in 2018 in Delaware after a traveler had been exposed in South America.

"Worldwide, it is estimated that from 10,000 to over 100,000 infections occur each year, with the largest burden in Asia and Europe," the World Health Organization (WHO) says. Historically, the Americas have reported hundreds of cases each year.

Given that rodents spread hantaviruses, people who are more likely to encounter these animals have a greater chance of developing hantavirus disease. So forestry workers, farmers and trappers are at higher risk than the general population.

Causes: Humans can develop hantavirus disease after being exposed to the urine, droppings or saliva of infected rodents. This can happen if a person rubs their eyes after touching bodily fluids or poop carrying the virus. Additionally, if someone disrupts debris containing infected animal droppings — while cleaning a barn, for instance — hantaviruses can be released into the air and then inhaled. On rare occasions, people may develop hantavirus disease after being bitten by an infected rodent.

The Andes virus, which can transmit between people, has been associated with several clusters of infection in recent years, including the 2026 cluster associated with the cruise ship MV Hondius.

Once inside the body, hantaviruses can cause two types of serious infections: hantavirus cardiopulmonary syndrome (HCPS) and hemorrhagic fever with renal syndrome (HFRS). (Note that HCPS is sometimes called hantavirus pulmonary syndrome; these two terms refer to the same condition.)

Hantaviruses in the Americas are known to cause HCPS, while those in Europe and Asia cause HFRS.

Symptoms: Early symptoms of HCPS include fever, muscle aches and fatigue, which can take one to eight weeks to develop following exposure to a hantavirus. Additional symptoms include chills, headaches, dizziness and gastrointestinal issues. Within four to 10 days of the first symptoms, the disease can progress to cause coughing, shortness of breath, shock and fluid buildup in the lungs.

Approximately 38% of patients who develop these respiratory symptoms die from the disease, the U.S. Centers for Disease Control and Prevention (CDC) states. Case fatality rates up to 50% have been reported in some contexts, the WHO says.

By contrast, HFRS is less deadly, with case fatality rates between 1% and 15% depending on the virus at fault. Symptoms usually emerge within one to two weeks after exposure to a hantavirus, but they can take up to eight weeks to appear. Early symptoms include intense headaches, back and abdominal pain, fever, chills, nausea and blurred vision. Later stages of the disease involve low blood pressure, lack of blood flow, internal bleeding and kidney failure.

Treatments: There is no cure for hantavirus disease. Instead, treatment aims to manage a patient's symptoms and stabilize their vitals. Doctors may provide a patient breathing support if they have respiratory issues, or dialysis if their kidneys are too damaged to filter blood properly.

Prevention: To reduce exposure to hantaviruses in the first place, the U.S. Centers for Disease Control and Prevention (CDC) recommends that people eliminate or minimize their contact with wild rodents. They can do this by storing food securely, sealing any holes or gaps in their houses or garages to prevent rodents from entering, and using traps when rodents have already infiltrated, for example.

Tips for safely cleaning up rodent droppings can be found on the CDC website.

When it comes to the Andes virus, which can spread between people, healthcare providers caring for infected patients should wear personal protective equipment and employ other standard safety procedures, such as hand hygiene, environmental cleaning, and safe handling of blood and bodily fluids.

"During outbreaks or when cases are suspected, early identification and isolation of cases, monitoring of close contacts, and application of standard infection prevention measures are important to limit further spread," the WHO says.

For people outside healthcare, the precautions recommended to avoid Andes virus infection are similar to those recommended to avoid more common illnesses like the flu or common cold. These include avoiding kissing or sexual contact with potentially infected people, as well as avoiding sharing drinks and eating utensils. It's also advisable to wash hands frequently and maintain distance from potentially infected people.

Recent cases: In February 2025, the American classical pianist and businesswoman Betsy Arakawa, who was also the wife of actor Gene Hackman, reportedly died from HCPS.

In April 2026, the cruise ship MV Hondius was struck by a cluster of hantavirus cases that were later confirmed to be caused by the Andes virus, the only hantavirus known to spread from person to person.