For health professionals: Valley fever (coccidioidomycosis)

Get detailed information on valley fever for health professionals.

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What health professionals need to know about valley fever

Valley fever is an infection caused by a fungus called Coccidioides. The fungus is found in the dust and soil of:

  • some areas of the Southwestern U.S., including:
    • Arizona
    • California
    • Nevada
    • New Mexico
    • Texas
    • Utah
  • south-central Washington State in the U.S.
  • Mexico
  • Central America
  • South America

The spores can get into the air when the soil is disrupted by:

  • farming
  • construction
  • the wind
  • outdoor activities, such as:
    • landscaping
    • gardening
    • any digging, such as for fossils or bones
    • recreational activities, such as dirt biking

Valley fever can result when these spores are inhaled.

Primary cutaneous coccidioidomycosis, solid organ donor-derived coccidioidomycosis and fomite-transmitted coccidioidomycosis can also occur, but are very uncommon.

Valley fever should not be confused with Rift Valley fever. The latter is a viral infection that usually affects both animals and humans in Africa.

There is no vaccine or medication to protect against valley fever.

Clinical manifestations

Monitor for symptoms.  


Diagnosis of coccidioidomycosis can be established using serologic, histopathologic and culture methods.


Coccidioidomycosis is generally self-limiting and will resolve without treatment.

Disseminated infections, or patients who experience excessive morbidity, should be treated with antifungal medication. The type of drug and length of treatment depends on:

  • the site and severity of infection
  • clinical response

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