Valley fever, a rapidly spreading lung infection caused by a soil fungus, has increased exponentially in California and could exceed last year’s record of 12,500 cases.
As of July 31, the California Department of Public Health (CDPH) reported more than 5,500 cases across its provinces.
In contrast, 7,000–9,000 cases were reported every year from 2017 to 2023.
Traditionally concentrated in the Central Valley and Central Coast, infections have started to be reported in the Bay Area.
Alameda County has reported nearly 72 cases in 2025, and Contra Costa County 105, with a total of 333 cases across the nine-county Bay Area.
What is Valley fever?
Valley fever is caused by inhaling spores from disturbed soil, Coccidioides.
Its symptoms include cough, dizziness, dyspnea, night sweats, joint pain, and muscle soreness.
CDPH mentioned, “You can get valley fever from just one breath of dust from outdoor air that contains spores.”
Moreover, individuals exposed to soil disturbance are at an increased risk of contracting the infection.
Experts attributed the increasing cases of Valley fever to climatic changes, as cycles of rain after drought create ideal conditions for the fungus.
