Expert Q&A: What is hantavirus and what you need to know

(SACRAMENTO)

Public health officials around the world are on high alert after a hantavirus outbreak was reported on a cruise ship in the Canary Islands.

Health agencies in several countries are working quickly to contain the spread. So far, there have been several confirmed cases and even more suspected infections. As the situation develops, growing concern is focused on whether this outbreak could expand and become more widespread, similar to what happened during the COVID-19 pandemic.

To help explain what this means and how people can stay safe, we spoke with UC Davis Health infectious disease expert Dean Blumberg about what you need to know about hantavirus.

What is hantavirus?

Hantavirus refers to a group of about 40 related viruses. These viruses can cause two main types of illness in humans.

In the United States, the most common illness is hantavirus pulmonary syndrome (HPS), which affects the lungs. In other parts of the world, different strains can cause hemorrhagic fever with renal syndrome (HFRS), which affects the kidneys and can cause bleeding problems.

How is hantavirus spread?

Hantavirus is mainly spread through contact with infected rodents or their droppings, urine or saliva.

In the western United States, including California, the primary carrier is the deer mouse. These mice are usually found at higher elevations, especially above about 2,900 feet, such as in the eastern Sierra Nevada.

People living in lower-elevation areas like Sacramento or the Bay Area are at very low risk. Common rodents like house mice, rats, or squirrels in these areas are not known to spread hantavirus.

To stay safe, practice good hygiene. If you are cleaning areas where rodents may be present:

• Avoid sweeping dry droppings
• Wear gloves and a mask
• Clean carefully to avoid breathing in particles

How common is hantavirus in the United States?

Hantavirus is rare. Each year, there are usually 20 to 40 cases reported nationwide. Most cases occur in the western U.S.

What are the symptoms of hantavirus?

In the U.S., hantavirus pulmonary syndrome usually starts suddenly with flu-like symptoms, including:

• Fever
• Muscle aches
• Nausea
• Vomiting

After a few days, symptoms can quickly become severe. Fluid can build up in the lungs, making it hard to breathe and lowering oxygen levels.

When should you seek medical care?

You should seek immediate medical attention if you have trouble breathing or feel like you are not getting enough oxygen.

Severe respiratory symptoms are the main reason people with hantavirus go to the hospital.

How is hantavirus treated?

There is no specific cure for hantavirus. Treatment focuses on supportive care, which includes:

• Oxygen support
• Maintaining fluid levels
• Supporting blood pressure

Although the illness can worsen quickly, early and strong medical support can lead to rapid improvement, often within 1-2 days.

In serious cases, patients may need:

• A ventilator
• Advanced life support, such as a heart-lung machine

Can hantavirus spread from person to person?

The type of hantavirus found in the U.S. (HPS) does not spread from person to person.

However, some rare strains in other countries - such as the Andes virus in South America - can spread between people, but this is uncommon.

What happened with the cruise ship hantavirus cases?

Initial reports suggest that exposure may have started during a birdwatching trip in an area where the Andes virus is present.

The virus may have then spread among passengers on the cruise ship due to close contact in crowded conditions.

The Andes virus is found in countries like Argentina. It is still rare, with only a few dozen cases reported each year, usually linked to contact with rodent-infested areas.

Could hantavirus become a pandemic like COVID-19?

No, hantavirus is very unlikely to cause a pandemic like COVID-19.

There are several reasons:

• Low transmission: Most hantaviruses do not spread between people. Even in rare cases, spread is limited.
• Long incubation period: Symptoms usually appear one to six weeks after exposure, which slows the spread.
• Low contagiousness: On average, an infected person spreads it to fewer than one other person.

For comparison, COVID-19 spread much more easily and quickly, with each case infecting multiple people. Because hantavirus spreads slowly and inefficiently, outbreaks tend to die out quickly rather than grow.

Watch VideoAs concerns grow over recent hantavirus cases linked to a cruise ship outbreak, many people are wondering: Could hantavirus become the next pandemic like COVID-19?