Valley Fever cases rise across West Coast

A rising Valley Fever outbreak prompts questions about diagnosis and climate driven spread.

Experts warn of new epidemic as deadly fungus spreads faster than ever in US

Valley Fever, caused by the fungus coccidioides, is spreading on the US west coast. California reports more than 5 500 provisional cases in the first half of 2025, a pace that would exceed last year. Arizona recorded 14 000 cases in 2024, up from 2023, signaling an ongoing uptick. Nationwide cases appear headed toward nearly 30 000 in 2025 if current trends continue. The disease is not transmitted from person to person and starts when spores are inhaled from disturbed soil. Symptoms mimic pneumonia, including fatigue cough fever and breathlessness, which often leads to missed or wrong diagnoses. The CDC estimates the true burden could be between 206 000 and 360 000 cases annually, far higher than reported figures. Most mild cases need rest, but severe infections require antifungal medicines. There is no human vaccine yet although a dog vaccine exists as a stepping stone. A university project has received 33 million from the NIH to pursue a human vaccine still in development. California public health director Dr Erica Pan urges vigilance in recognizing symptoms for those who have outdoor exposure and illness lasting seven to ten days. Climate patterns such as wet winters followed by dry windy periods are linked to the fungus growth and spread, raising concerns about a wider endemic zone. Public health officials emphasize ongoing surveillance and funding to manage a disease that is likely here to stay.

The rise of Valley Fever is not just a medical footnote. It exposes gaps in diagnosis and places stress on a health system already stretched by seasonal infectious diseases. Experts tie the surge to climate patterns that create windows for fungal growth and airborne spread, a reminder that public health now intertwines with climate policy. The research push toward a human vaccine remains tentative, with a working vaccine for dogs offering proof of concept but no ready human solution. The numbers fuel urgency for better clinician training and more transparent funding so routines like testing and reporting keep pace with a changing geography. In short, this is a climate related health challenge that requires sustained attention from clinicians, researchers, and policymakers alike.

Highlights

The next steps depend on better detection and steady investment rather than headlines