A dangerous fungal infection once limited to the American Southwest is spreading to new regions, raising concerns among health officials. Valley fever, a lung infection caused by the fungus Coccidioides, is now being detected outside its traditional hotspots and affecting a growing number of people.

A Rising Threat

According to USA Today, Valley fever peaks in the fall and winter. While the disease is not contagious, in rare cases it can become flesh-eating and life-threatening. In California alone, reported cases have skyrocketed from about 1,000 two decades ago to nearly 12,500 in 2024.

Those most at risk include farm and construction workers who disturb soil, as well as golfers and residents in newly developed suburban areas where fungal spores may be present. Infection occurs when a person inhales the spores.

Symptoms to Watch For

Valley fever typically begins with flu-like symptoms appearing one to three weeks after exposure:

• Fever
• Cough
• Fatigue
• Shortness of breath

Some patients may also develop joint pain, headaches, or a rash on the upper body and legs.

While most cases are mild and resolve on their own, people with weakened immune systems face greater danger. In rare cases, the infection spreads to other parts of the body, becoming disseminated infection, which can be fatal without prompt treatment.

Diagnosis and Treatment

There is currently no vaccine for Valley fever. The CDC recommends antifungal medications to reduce the risk of severe illness. Early detection is key, but doctors often misdiagnose the infection because symptoms mimic bacterial or viral pneumonia. Misdiagnosis can delay proper antifungal treatment, sometimes with serious consequences.

Valley fever can also affect pets, though it does not spread between animals and people.

Hot Spots and Risk Factors

California health officials have identified Salinas Valley as a particular hot spot, but the disease is spreading beyond traditional regions. Those at greatest risk are people exposed to disturbed soil, especially in agriculture and construction.

What You Can Do

If you live or work in an area where Valley fever is present and develop flu-like symptoms, it’s important to seek medical care and ask about testing. Early diagnosis and treatment with antifungal medications can save lives.