- Public Health
- Diseases We Track
- Valley Fever
Valley fever (also called coccidioidomycosis, or cocci) is an infection caused by the fungus Coccidioides, that can be found in the soil. The term “Valley fever” usually refers to Coccidioides infection in the lungs but the infection can spread to other parts of the body in severe cases.
The fungus is found in the soil throughout the southwestern United States (Arizona, California, Nevada, New Mexico, Texas, and Utah) and in Central and South America. Coccidioides has also been identified in other parts of the United States including south-central Washington.
Confirmed valley fever cases in Maricopa County as of 12/7/2022
This table is updated monthly
Number of new cases reported in December
Number of cases reported from 1/1- 12/31
Total number of cases reported for the year
*Note: 2021 and 2022 data are preliminary and subject to change.
Most people who get Valley fever never experience any symptoms. About 40% of people will experience symptoms, which may appear between one to four weeks after they breathe in the fungal spores. Symptoms may include:
- Fatigue (tiredness)
- Shortness of breath
- Night sweats
- Muscle aches or joint pain
- Rash on upper body or legs
In extremely rare cases, the fungal spores can enter the skin through a cut, wound, or splinter and cause a skin infection.
Duration of symptoms
Symptoms of Valley fever can often last for a few weeks to a few months.
- Between 5% and 10% of people with Valley fever develop serious or long-term problems in their lungs.
- People with disseminated infection can have symptoms lasting much longer. About 1% of people have disseminated Valley fever, which occurs when the infection disseminates, or spreads, to other parts of the body, such as the skin, bones, joints, and/or brain. Disseminated Valley fever typically requires life-long medication.
- Some people may have symptoms that go away without any treatment.
If symptoms last for more than a week, a healthcare provider should be contacted.
Healthcare providers will rely on travel history and laboratory tests to help diagnose Valley fever infection. The most common test for Valley fever is to test for Coccidioides antibodies or antigens in blood. Healthcare providers may also do lung imaging tests to look for Valley fever pneumonia, such as x-rays or CT scans. Less commonly, a healthcare provider may perform a tissue biopsy, where they take a small sample of tissue from the body and examine it under the microscope.
Any healthcare provider can order a Valley fever test. If you believe you may have Valley fever, ask your healthcare provider to get a Valley fever test.
Not everyone with Valley fever will need treatment and many will improve on their own. However, a healthcare provider may want to closely monitor someone with Valley fever. If a healthcare provider determines treatment is needed, they may prescribe anti-fungal medications.