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Lung Disease & Respiratory Health Center

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Hantavirus Pulmonary Syndrome (HPS) - Topic Overview

What is hantavirus pulmonary syndrome?

Hantavirus pulmonary syndrome (HPS) is a lung infection caused by viruses found in the saliva, urine, and droppings of some rodents. The illness is rare but can be deadly.

The first known outbreak of HPS in the United States occurred in 1993. Most of the U.S. cases have happened during the spring and summer in the Southwest.

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What causes HPS?

Most cases of HPS in the U.S. are caused by one type of hantavirus found in the deer mouse. People can become infected by:

  • Breathing in tiny airborne particles that come from rodent urine.
  • Touching rodent urine, saliva, or droppings.
  • Coming in contact with dust contaminated with the virus.
  • Being bitten by an infected mouse.

North America has never had a known case of one person spreading the illness to another. And people do not get HPS from farm animals, pets, or insects. But your pet may bring home an infected rodent.

What are the symptoms?

Symptoms usually start 2 to 3 weeks after a person has been exposed to the virus. Early symptoms may include:

You quickly will become very sick. Within a few days, you'll start to have more serious symptoms, such as:

  • Shortness of breath.
  • Coughing.
  • A fast heartbeat and fast breathing. These are signs of fluid buildup in the lungs (pulmonary edema).

After a person with HPS starts having trouble breathing, he or she may die within hours. Most deaths occur within 1 to 2 days after severe breathing problems begin. About 4 out of 10 people who get HPS do not survive.1

How is HPS diagnosed?

Your doctor will do a physical exam and ask you questions about your symptoms, past health, and exposure to rodents. You may have other tests, such as chest X-rays, a complete blood count, and an oxygen saturation test.

Your doctor will know for sure that you have HPS only if you have the signs of HPS and if tests show that the virus is or has been in your blood or tissues.

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