Hantavirus pulmonary syndrome (HPS) is a rare, but serious disease that can be life-threatening. A family of viruses called hantavirus cause HPS and a variety of other diseases.
Key Facts:
- HPS is rare and spread primarily from rodent to person.
- Symptoms include abrupt onset of fever, chills, weakness, nausea, vomiting and abdominal pain followed by difficulty breathing.
- HPS has a mortality rate of up to 40%, which makes prompt identification and treatment so important.
More About Hantavirus
Hantavirus is found worldwide and split into two categories, New World hantavirus and Old-World hantavirus. Old world hantaviruses are found in Europe and Asia cause a form of kidney disease called hemorrhagic fever with renal syndrome (HFRS). New World hantaviruses are found in the Americas and attack the lungs, causing HPS.
HPS was first identified as a disease occurring in the United States during an outbreak in the 1990s. You may hear HPS referred to as hantavirus cardiopulmonary syndrome (HCPS) due to the damage that the disease often causes to both the heart and the lungs.
The deer mouse is the primary carrier of the virus, with other carriers including the white-footed mouse, cotton rat and rice rat. The house mouse and Norway rat most frequently encountered in urban communities are not carriers.
According to the Centers for Disease Control and Prevention (CDC), 864 cases of hantavirus were identified in the United States between 1993 and 2022. This figure included 30 cases of non-pulmonary hantavirus, while the remaining were cases of HPS. Hantavirus has been identified in 40 states, with most cases occurring west of the Mississippi River.
How Hantavirus Pulmonary Syndrome (HPS) Affects Your Body
You can become infected through contact with saliva, feces or urine of an infected rodent. This can happen through inhalation or through direct contact via the mouth, eyes, a wound or being bit or scratched by an infected rodent. The Andes variant, a type of hantavirus primarily found in South America, is unique in that it can be spread from rodents as well as person to person through prolonged close contact with a symptomatic individual. Once the virus enters your body, it replicates and spreads throughout. When it reaches your lungs, it infects the endothelial cells that line the tiny blood vessels of your lungs, also known as the capillaries. This causes the capillaries to leak, filling your lungs with fluid and making breathing extremely difficult.
When the virus infects your heart, it causes damage that reduces your heart’s ability to pump blood throughout your body. The lack of oxygenated blood causes very low blood pressure (“shock”) as oxygen is not available to all the cells of your body. This can rapidly lead to organ failure throughout your body, resulting in a high likelihood of death.
Who Is at Risk?
Rural populations in the western United States are at a higher risk for contracting HPS. However, anyone that is in contact with rodent habitats could become sick. Sites such as farming buildings, hiking shelters or campsites, basements or attics, sheds or other infrequently used buildings, seasonal campers or RVs and construction sites are examples of areas that are more likely to host rodent populations. Occupations, such as farming, construction, pest control, janitorial work and utility work can increase your risk of exposure.
Additionally, any activity that puts you in contact with rodent habitats, such as cleaning up rodent droppings or nests, opening spaces that haven’t been used and frequenting crawl spaces or attics, can increase your risk of contracting HPS. Sweeping, vacuuming and disturbing spaces that are contaminated with hantavirus can stir up rodent saliva, urine and droppings, making them airborne and respirable. Just because you do not see any rodents doesn’t mean that the risk of HPS is not there.
Reviewed and approved by the American Lung Association Scientific and Medical Editorial Review Panel.
Page last updated: May 15, 2026
