Understanding Valley Fever (Coccidioidomycosis)

Valley fever is an infection caused by a fungus that is breathed in from dust in the environment. It's also called coccidioidomycosis after the fungus (Coccidioides) that causes it. Valley fever most often causes lung infection (pneumonia). It's mainly found in the southwest U.S., as well as Mexico and parts of Central and South America. It doesn’t spread from person to person. 

What causes Valley fever?

Valley fever is caused by a fungus (Coccidioides) . This fungus lives in dry soil. In the U.S. it is found mainly in the Southwest. Infection can occur after breathing in spores of the fungus. The spores may get into the air during windy weather. Or they may get into the air from activities that raise dust, such as farming and construction work. Anyone who lives in, works in, or travels to areas where the fungus is found is at risk of getting infected.

What are the symptoms of Valley fever?

Many people who are infected have no symptoms. If symptoms do occur, they often start within 3 weeks of breathing in the spores. Symptoms can range from mild to severe. Common symptoms include:

• Extreme tiredness (fatigue)

• Not feeling well

• Fever

• Chills

• Night sweats

• Cough

• Chest pain or shortness of breath

• Muscle aches and joint pain

• Rash

Most people with symptoms get better in a few weeks or months. Some people are more likely to progress to severe symptoms if infected. You are more likely to have severe symptoms if you:

• Have a weak immune system. This might be from cancer or HIV.

• Take medicines that weaken the immune system

• Are pregnant

• Have diabetes

• Are older than 60

• Are African American or Filipino

How is Valley fever treated?

Treatment depends on how serious the infection is.

• More than half of people infected have no symptoms at all. Mild cases need little more than treatment of symptoms. You may use over-the-counter medicines to help ease symptoms.

• Severe cases need treatment with antifungal medicines. These help kill the fungus causing the infection. You may need to take these for 3 to 6 months or longer. You may also need to take these medicines if you are at high risk for complications.

What are the possible complications of Valley fever?

Complications are more likely to occur with severe cases. They can include:

• Long-term (chronic) symptoms such as cough, fever, extreme tiredness (fatigue), or bloody sputum

• Severe pneumonia and other lung problems. These can cause more sputum, shortness of breath, and less stamina.

• The infection spreads to other parts of the body. These areas may include the brain, spinal cord, skin, joints, or bones.

How can I prevent Valley fever?

If you live in or travel to areas where Valley fever can occur, the tips below may help reduce the risk for infection. During windy weather or dusty conditions:

• Stay indoors. Also keep your windows and doors closed at home.

• Keep car windows closed when you are driving.

• Wear a mask that covers your nose and mouth if you have to be outdoors.

If you work in an area where Valley fever occurs, follow these tips to reduce your dust exposure and your risk for infection:

• Don't work in dust storms or high winds.

• Don't do much digging by hand. Instead use heavy equipment with enclosed, air-conditioned, HEPA-filtered cabs.

• Keep soil constantly wet while digging or moving earth.

Workers and managers should all have training on:

• Areas where this infection occurs

• What the symptoms are and when to report them

• Who is at highest risk of serious disease

When should I call my healthcare provider?

Call your healthcare provider right away if you have any of these:

• Severe weakness or tiredness (fatigue) that doesn't get better

• Fever of 100.4°F (38 °C) or higher, or as advised by your provider

• Coughing with blood-tinged mucus

• Painful red or brown rash on the legs that may spread to other body areas

• Unexpected weight loss

• Skin sores

• Swollen lymph nodes

• Joint swelling

• Confusion

• Stiff neck

• Seizures