Valley Fever Still Rising in California

The California Department of Public Health identified more than 5,500 provisional cases of Valley fever in the state through the first six months of 2025, according to a recent news release from CDPH. Valley fever, also known as coccidioidomycosis, is caused by inhalation of Coccidioides fungal spores, which are present in the soil of semiarid areas such as California’s Central Valley and much of the southwestern United States. While most cases of Valley fever do not result in serious illness, some people develop pneumonia, and it can lead to chronic, severe, or fatal outcomes if not treated.

The trend puts California on track to exceed the 7,000 to 9,000 cases the state identified annually between 2017 and 2023. Last year, California reported a record high of nearly 12,500 cases.

According to CDC, approximately 20,000 cases of Valley fever are reported each year in the U.S., but this estimate is likely a severe undercount. The true burden of Valley fever in the U.S. is between 206,000 and 360,000 cases, CDC says.

Workers in endemic areas who are exposed to dust from disturbed soil have a higher risk of contracting Valley fever. NIOSH identifies the disease as a concern for workers in agriculture, archeology, construction, geology, the military, firefighting, mining, and oil and gas extraction. Workers can protect themselves by stopping work in dust storms or high winds, minimizing hand digging, wetting soil when digging or moving earth, and using digging equipment that has enclosed, HEPA-filtered cabs. The agency recommends respiratory protection for workers who dig manually or who work near earth-moving equipment in endemic areas.

For more information on Valley fever, read the CDPH press release and visit the CDC and NIOSH websites.