Should You Be Worried About Hantavirus?
An infectious disease expert explains what to know about hantavirus, including how it spreads and how to stay safe.
A cluster of hantavirus cases on a trans-Atlantic cruise ship has caused alarm about the rare, but potentially dangerous, virus. Hantaviruses are a family of viruses that come from contact with rodents, like rats or mice. There are different types of hantaviruses, and for the most part the disease can only spread from exposure to rodents. The Andes virus is the only type of hantavirus that can spread from person-to-person, and the rodents that carry the Andes virus have not been found in the United States, according to the Centers for Disease Control and Prevention.
Though only 890 cases were reported in America between 1993 and 2023, it is estimated there are between 10,000 and 100,000 cases each year globally, with most infections occurring in Asia and Europe.
“The virus has circulated in South America for decades without causing widespread outbreaks beyond those household or close-contact clusters, so the overall risk remains extremely low,” says Dr. Jason Zucker, an infectious disease physician at NewYork-Presbyterian/Columbia University Irving Medical Center. “The best way to prevent hantavirus is to control rodents both inside and outside the home.”
To learn more about hantavirus, the risks it poses in the community, and how to prevent exposure, Health Matters spoke with Dr. Zucker.
What is hantavirus?
Dr. Zucker: Hantavirus is a family of viruses carried primarily by rodents that can cause serious and sometimes fatal illness in people. There are many strains worldwide, and they cause two main types of disease in humans: hantavirus pulmonary syndrome (HPS), which affects the lungs and is the form seen in the Americas, and hemorrhagic fever with renal syndrome (HFRS), which affects the kidneys and is more common in Europe and Asia.
How does the disease spread?
Dr. Zucker: People traditionally get hantavirus from contact with rodents like rats and mice, especially when exposed to their urine, droppings, and saliva. It can also spread through a bite or scratch by a rodent, but this is rare. The virus can be easily released into the air in confined spaces when disturbed by rodents or human activities, such as sweeping or vacuuming.
Breathing in the virus is the most common way of getting infected; however, people can also become infected by touching their mouth or nose after handling contaminated objects or surfaces.
The Andes virus, the one that is being talked about currently, is the only type of hantavirus known to spread from person to person.
So the Andes strain of hantavirus can be spread from person to person?
Dr. Zucker: Yes, with important caveats. The Andes virus is the only type of hantavirus known to spread person to person, and this spread is usually limited to people who have close contact with the ill person.
Although rare, transmission between people has typically required close, prolonged contact with a symptomatic person. This could include direct physical contact, prolonged time spent in close or enclosed spaces, and exposure to the infected person's saliva, respiratory secretions, or other body fluids, such as kissing, sharing utensils, or handling contaminated bedding.
Does hantavirus spread easily in communities?
Dr. Zucker: Person-to-person transmission of Andes virus occurs mainly in family clusters or, less commonly, after activities involving close contact with an infected person, primarily during the early stages of the disease.
A prospective study in Chile found that sexual partners and other close household contacts of people with Andes virus showed a ten-fold higher risk of acquiring the virus than household contacts who did not share a bed or bedroom.
This is different from COVID-19, which spreads efficiently through brief, casual contact and in well-ventilated settings. Andes virus requires the kind of sustained, intimate contact more typical of household or close caregiver settings.
How common is it in America and worldwide?
Dr. Zucker: Globally, hantavirus infections are relatively uncommon. Worldwide, it is estimated that between 10,000 and over 100,000 infections occur each year, with the largest burden in Asia and Europe.
What are the symptoms?
Dr. Zucker: Symptoms of hantavirus pulmonary syndrome usually start to show one to eight weeks after contact with an infected rodent.
Early symptoms include:
- Fever
- Fatigue
- Muscle aches
- Nausea
- Vomiting
- Diarrhea
- Headache
Four to ten days after the initial phase of illness, late symptoms appear. These include:
- Coughing and shortness of breath
- Tightness in the chest
- Fluid buildup in the lungs
How is it treated?
There is no specific treatment for hantavirus infection. Patients should receive supportive care, including rest, hydration, and treatment of symptoms. The virus can cause breathing difficulties, and patients may need breathing support such as intubation. Early hospitalization and intensive care significantly improve the chances of survival. The key is seeking medical care quickly if hantavirus is suspected.
Is hantavirus fatal?
Dr. Zucker: It can be. Among patients who develop severe respiratory symptoms, the case fatality rate has been estimated at approximately 38%. That said, not everyone who is infected develops severe disease, and early supportive care in a hospital improves outcomes considerably.
Is there a risk this hantavirus outbreak turns into another global pandemic?
Dr. Zucker: It's highly unlikely. The overall risk to travelers and the American public remains extremely low, and routine travel can continue as normal. Person-to-person transmission of Andes virus requires prolonged, close, intimate contact and has only been documented in limited cluster settings.
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