Valley fever (coccidioidomycosis) is a lung infection that the fungus Coccidioides causes. The fungus grows in the soil in parts of the U.S. and Central and South America. Valley fever usually doesn’t cause symptoms, or symptoms go away on their own. Rarely, you can have ongoing lung issues or a serious illness, and may need antifungal medication.

What Is Valley Fever?

If you have symptoms of Valley fever, they’re often flu-like. But an ongoing infection can cause other symptoms.

Valley fever is a fungal infection in your lungs. You get it from breathing in the fungus Coccidioides (cahk-sid-ee-OY-deze) from the environment. The fungus lives in the soil in the southwest U.S., parts of Washington state and in Central and South America.

Valley fever is the earliest stage of a Coccidioides infection. If you have a Coccidioides infection, you may have flu-like symptoms or no symptoms at all. But it can sometimes progress to more serious stages.

About 20,000 people get Valley fever each year. The infection is most common in California and Arizona.

Another name for Valley fever is coccidioidomycosis (cahk-sid-ee-oy-doh-my-KOH-sis).

Symptoms and Causes

Symptoms of Valley fever

In many cases, the infection doesn’t cause symptoms. But if you do have Valley fever symptoms, they may include:

Healthcare providers sometimes call bumps (nodules), fever and joint stiffness “desert rheumatism.”

How does a person get Valley fever?

There are two types of Coccidioides fungi that cause Valley fever:

  • Coccidioides immitis (C. immitis). This fungus grows in soil in California.
  • Coccidioides posadasii (C. posadasii). This fungus grows in other parts of the U.S. and Central and South America.

Both types cause the same symptoms.

Disturbing soil causes the fungi to break apart. When they break apart, it releases its tiny reproductive parts (spores) into the air. When you breathe in (inhale) the spores, they can settle in your lungs and grow into larger clusters of more spores (spherules).

Spherules can break apart and send more spores out into other parts of your lungs or even other parts of your body. Those spores can grow into spherules and keep spreading the fungus throughout your body.

Is Valley fever contagious?

No, Valley fever isn’t contagious. You can’t spread Valley fever to another person. But sometimes, outbreaks happen in areas where a lot of dirt and dust enter the air, like areas with high winds or construction.

In extremely rare cases, you might be able to inhale spores from an open wound on someone who has Valley fever. This is very unlikely. Most of the time, the only way to get Valley fever is to inhale spores from the air outdoors.

Risk factors

Anyone who breathes in C. immitis or C. posadasii fungi can get Valley fever. But it’s more common if you’re over 60.

You’re also at a higher risk of Valley fever if you:

Complications of Valley fever

Valley fever complications are uncommon. About 5 to 10 out of every 100 people develop serious symptoms. And the infection spreads to other parts of the body in about 1 out of every 100 people.

But if you develop serious complications, they may include:

An infection that spreads outside of your lungs is one of the most serious Valley fever complications. It can spread to your:

When coccidioidomycosis spreads to your brain, you can develop coccidioidal meningitis. Coccidioidal meningitis is a life-threatening condition and causes neurological symptoms like vision and hearing changes, headaches and neck stiffness.

Diagnosis and Tests

How doctors diagnose Valley fever

A healthcare provider will review your medical history, ask about your symptoms and travel history, and perform a physical exam. To help confirm a Valley fever diagnosis, they may recommend tests like:

  • Biopsy. A provider takes a small amount of tissue and sends it to a lab to look for signs of Coccidioides.
  • Blood tests. Blood tests are the most common way to diagnose Valley fever. They’ll send a blood sample to a lab to look for signs of Coccidioides, like antibodies or antigens.
  • Imaging tests. A provider may recommend a chest X-ray or CT scan to look for signs of Valley fever pneumonia.

Management and Treatment

How is Valley fever treated?

Valley fever treatment depends on how severe it is. Your healthcare provider may recommend a “watchful waiting” approach. That means you don’t need immediate treatment because you don’t have severe symptoms. But they’ll watch your condition with regular testing.

If you have a serious or ongoing infection, or if you have risk factors for severe illness (like chronic obstructive pulmonary disease or COPD), they may prescribe antifungal medications. These may include:

You may need to take antifungal treatments for three to six months. But it may be longer if you have a severe case of Valley fever or develop complications.

When should I see my healthcare provider?

Contact a healthcare provider if you live in or travel to an area where Coccidioides is common and you’ve had flu-like symptoms for more than a week.

If a provider diagnoses you with Valley fever, contact them or go to the nearest emergency room if you experience any of the following symptoms:

  • Blood in your saliva (spit)
  • Stiff neck
  • Trouble breathing
  • Vision or hearing changes

You may wish to ask your provider the following questions during your appointment:

  • Am I at a high risk for a severe Valley fever infection?
  • What type of Coccidioides fungi caused my infection?
  • What treatment do you recommend?
  • Should I look out for any other symptoms?
  • When should I go to the ER?

Outlook / Prognosis

What can I expect if I have Valley fever?

Most people recover from Valley fever without any long-term problems. But a small number of people develop ongoing lung infections. These can take a long time to go away — sometimes several years. Valley fever is fatal in fewer than 1 out of every 100 people who have it.

In rare cases, the fungus can move to other parts of your body. Without treatment, coccidioidomycosis in your brain can be fatal.

How long does Valley fever last?

Coccidioidomycosis symptoms usually go away on their own after a few weeks or months.

A small number of people can have ongoing disease in their lungs. If it goes on for a long time, healthcare providers call it chronic (long-term) pulmonary coccidioidomycosis. Symptoms of chronic pulmonary coccidioidomycosis include:

Can you get Valley fever twice?

In most cases, if you get Valley fever and recover, you’re unlikely to get it again.

Prevention

Can Valley fever be prevented?

It’s challenging to avoid breathing in Coccidioides spores if you live in an area where they’re common. But you can help reduce your risk of Valley fever by:

  • Avoiding areas where you may encounter dirt or dust
  • Closing your windows and staying inside during dust storms
  • Running high-efficiency particulate air (HEPA) filters in your home
  • Wearing an N95 respirator mask during activities like gardening, digging or other yard work that can expose you to fungal spores

Additional Common Questions

How do I get rid of the fungus that causes Valley fever from my yard?

Coccidioides spores are very tiny — you can only see them with a microscope. There’s no easy way to identify them or remove them from your yard.

A note from Wockr

Valley fever can be hard to avoid if you live in areas where Coccidioides grows. Fortunately, most cases aren’t serious and go away on their own.

If you’re pregnant, over 60 or have a compromised immune system, it’s a good idea to take some extra steps to protect yourself. You can still enjoy the outdoors. But it’s a good idea to wear an N95 mask or stay indoors on particularly windy days. Talk to your provider about other ways you can protect your health and what symptoms you should keep an eye out for.