Valley fever causes thousands of cases in the US, and hundreds of people die of the infection
There have been more than 3,000 confirmed cases of Valley fever—also known as coccidioidomycosis - a potentially dangerous fungal infection that affects the lungs, according to health officials.
The data from the Centres for Disease Control and Prevention says 2025 has seen way more infections than last year, and another surge is expected soon. Valley fever is caused by a fungus that grows in western soil, which leads to severe or even long-term lung issues and can be fatal too if not treated on time and if it spreads to the brain.
Every year, Valley fever causes thousands of cases in the US, and hundreds of people die of the infection. According to doctors, the bacteria are common in the southwest US, parts of Washington state, and Central and South America. The infection is most common in California and Arizona.
What is Valley fever?
Doctors say you can get Valley fever from breathing in the fungus Coccidioides from the environment. It is the earliest stage of a Coccidioides infection, and those affected will have no symptoms or flu-like symptoms, but it can sometimes progress to more serious stages of coccidioidomycosis.
Even though it is not contagious, sometimes there are outbreaks where a lot of dirt and dust have been disturbed.
How do you get Valley fever?
There are two forms of Coccidioides fungi that can cause Valley fever:
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Coccidioides immitis (C. immitis) grows in the soil in California
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Coccidioides posadasii (C. posadasii) grows in other parts of the U.S. and Central and South America
They both lead to the same symptoms. Disturbing the soil, particularly during construction or dust storms, breaks apart the fungus, which releases its reproductive parts into the air. And if you inhale the microscopic spores, they would settle in your lungs, where they can grow into larger clusters of more spherules. These spherules break apart and send more spores out into other parts of your lungs and sometimes other parts of your body, growing into spherules of more spores and keeping the fungus spreading in your body.
Signs and symptoms of Valley fever
While in many cases Valley fever does not cause any symptoms, if you do have them, they may include:
- Severe fatigue
- High fever
- Night sweats
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Coughs and colds
- Breathlessness
- Chronic headache
- Muscle aches and joint pain
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Erythema nodosum rash
When seen together, fever, nodules under the skin, and joint stiffness are sometimes also known as "desert rheumatism."
Who is at risk of Valley fever?
Doctors say if you breathe in the fungus, you can get infected, but Valley fever is most common in adults over age 60. However, a few other reasons you can be at risk include:
- Have a weakened immune system, which can be caused by certain medications or diseases like HIV/AIDS
- Are you in your last pregnancy trimester
- Have diabetes
- Are Black or Filipino
- Have a job that exposes you to soil dust
- Have recently traveled or moved to an area where the fungus lives
