Coccidioidomycosis (Valley Fever)

Page originally published 9/19/2024.

Coccidioidomycosis, also known as “Valley Fever” or “Cocci”, is a lung infection.

Coccidioidomycosis, also known as “Valley Fever” or “Cocci”, is a lung infection. Valley Fever is caused by Coccidioides, a fungus found in the soil. This fungus can be found in the Pacific Northwest and southwestern United States, and parts of Mexico, Central America, and South America. In California, the number of reported Valley Fever cases have greatly increased in recent years.

See below, or click the following links, to learn more about:

Prevention

There is no vaccine to prevent Valley Fever. It can be difficult to avoid breathing in Coccidioides fungus in areas where it lives in the environment. However, there are still ways to reduce exposure and infection, including:

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  • Avoid dust outside in places where Valley Fever is common, as well as dusty areas outside, like construction or excavation sites.
    • If this is not possible, wear a fitted N95 respirator.
    • Avoid digging, gardening, or yard work in these areas.
    • Use vacuums with HEPA air filters to clean contaminated equipment or surfaces.
    • Keep break areas at workplaces clean and free of dust.
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  • Stay inside and keepwindows and doors closed when it is windy outside and the air is dusty, especially during dust storms.
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  • While driving in areas where Valley Fever is common, keep car windows closed and use recirculating air, if available.
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  • Consider avoiding outdoor activities that involve close contact with dirt or dust, including yard work and digging, especially if you are in one of the groups at higher risk for getting Valley Fever, or getting very sick from Valley Fever.
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  • Use soil stabilizers or cover open dirt areas around your home with grass, plants, or other ground cover (like gravel or wood chips) to help reduce dusty, open areas.
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  • Use air filtration measures indoors, such as using portable HEPA cleaners, and change your filters often.
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  • Clean skin injuries well with soap and water to prevent infection.

Certain jobs and work activities put workers at risk for Valley Fever. See Valley Fever Prevention for Workers for more information, including where Valley Fever is found, who is at increased risk, and preventing exposure.  

Transmission (Spread)

People can get Valley Fever by breathing in dust from outdoor air that contains spores of Coccidioides fungus that grows in the soil.

  • When soil or dirt is stirred up by strong winds or while digging, dust containing these fungus spores can get into the air.
  • Anyone who lives, works, or travels in an area where the Valley Fever fungus grows can breathe in these fungus spores from outdoor dust without knowing it and become infected.
    • In rare cases, spores can enter through a cut, wound, or splinter and cause a skin infection.
  • Animals, including pets, can also get Valley Fever by breathing in fungus spores from dirt and outdoor dust.

Valley Fever is not contagious, meaning it cannot spread from one person, or animal, to another.  

Symptoms

Many people who are exposed to Coccidioides do not get Valley Fever. Most people who are infected with Valley Fever have no symptoms and their bodies will fight off the infection naturally. Symptoms include:

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  • Fatigue (tiredness), 
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  • Cough,
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  • Fever,
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  • Headache,
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  • Shortness of breath, 
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  • Night sweats, 
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  • Muscle aches or joint pain, and/or
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  • Rash on upper body or legs.

Symptoms of Valley Fever may appear between 1-3 weeks after a person breathes in the fungal spores. with symptoms usually lasting a few weeks to a few months. Some patients have symptoms that last longer than this, especially if the infection becomes severe. 

 

With severe infections:  

  • Approximately 5-10% of people who get Valley Fever will develop serious or long-term problems in their lungs.
  • In about 1% of people, the infection spreads from the lungs to other parts of the body, such as the central nervous system (brain and spinal cord), skin, or bones and joints.

If symptoms last for more than a week, contact your healthcare provider.

Diagnosis and Treatment

The symptoms of Valley Fever are similar to other respiratory diseases, including COVID-19, flu, and pneumonia caused by bacteria. Laboratory tests are needed to know whether symptoms are caused by Valley Fever (which is caused by a fungus) or a respiratory disease (caused by a virus).

 

If you are being checked for Valley Fever, your healthcare provider may:

  • Collect a blood sample and send it to a laboratory.
  • Do an imaging test, like an x-ray or CT scan, of your lungs.
  • Collect and test fluid from your respiratory tract or a biopsy.
  • Do a skin test (similar to a skin test for tuberculosis).

Many people who get sick with Valley Fever have mild symptoms. They often get better without medication within a few months.

For people with more serious infections, or risk factors for getting very sick, a healthcare provider may prescribe 3-6 months of oral antifungal medication. People may need antifungal treatment if they have severe lung infection, or if the infection has spread to other parts of the body. These people may need to be hospitalized and the course of treatment is usually longer than 6 months.  

Resources

Educational Materials

County of San Diego

California Department of Public Health (CDPH)

Centers for Disease Control and Prevention (CDC)

Workplace Resources

For more information, contact the Epidemiology Unit at (619) 692-8499 or send us an e-mail.