New Study Urges Earlier Detection of Valley Fever as Cases Climb

Missed Diagnoses, Growing Burden

Valley fever, or coccidioidomycosis, is caused by inhaling fungal spores that live in soil. While once considered a regional illness concentrated in the southwestern United States, it has now expanded beyond traditional boundaries and affected far more people than reported data suggests.

Researchers estimate that between 205,000 and 360,000 symptomatic cases occur annually — far higher than official counts. A major challenge is delayed recognition, with many patients waiting weeks for an accurate diagnosis while often receiving ineffective antibiotics. Because symptoms such as fatigue, cough, fever and shortness of breath resemble more common respiratory illnesses, the infection is frequently overlooked in early stages.

“Eighty percent of people with Valley fever don’t get the correct diagnosis until a median of 23 days after their first clinical contact, if they even get tested,” Adebiyi said. “That’s a lot of illness, a lot of days lost from work and a lot of unnecessary antibiotics.”

Cases are Rising

Overlapping environmental and demographic changes drive the increase in Valley fever. Adebiyi pointed to climate patterns as a key factor, with longer droughts followed by rainfall disrupting soil and increasing the spread of airborne spores. At the same time, expanding development is increasing exposure.

“As rural areas are almost becoming semi-urban, there’s more construction, which disrupts the soil,” she said.

Improved reporting has made the disease more visible, though many cases still go undiagnosed when symptoms are mild or resolve on their own.

The result is a disease that is both expanding geographically and still widely underrecognized — especially in areas where clinicians may not routinely consider it.

At the center of the study is the COCCI framework, a clinical guide designed to help nurse practitioners and other providers identify Valley fever sooner and manage it appropriately:

• Consider exposure: Assess whether patients live in or have traveled to endemic areas or have been exposed to dust, construction or soil disturbance
• Order diagnostic testing early: Especially for patients with persistent respiratory symptoms or those who do not respond to initial treatment
• Check for risk factors: Identify patients at higher risk for severe disease, including those who are immunocompromised, pregnant or have underlying conditions
• Check for complications: Evaluate for signs of more serious disease, such as neurologic symptoms or widespread infection
• Initiate appropriate care: Manage uncomplicated cases in primary care and refer severe or complex cases to specialists

At its core, the COCCI framework shifts clinical thinking from “treat first, test later” to “evaluate exposure, test early and manage deliberately.” Rather than relying on intuition, the framework provides a clear, step-by-step approach.

A defining feature of the COCCI framework is reassessment after initial care. Clinicians are encouraged to schedule follow-up visits, monitor symptoms and adjust treatment if patients do not improve.