In the last 10 years, infection rates in California and Arizona have risen 400 percent, prompting California to designate August as Valley Fever Awareness Month.


Valley Fever is caused by the inhalation of tiny airborne fungi (Coccidioides immitis) that live in the soil but are released into the air by soil disturbance or wind. The fungus attacks the respiratory system, causing infections that can lead to symptoms that resemble a cold, influenza, or pneumonia; and if left untreated or mistreated, infection can spread from the lungs into the bloodstream, causing inflammation to the skin, permanent damage to lung and bone tissue, and swelling of the membrane surrounding the brain, leading to meningitis, which can be devastating and even fatal.

California Department of Public Health (CDPH) Director and State Health Officer Dr. Karen Smith said, “Valley Fever is an ongoing concern in California and other areas of the Southwest United States.

“It is important for people living in Valley Fever areas to take steps to avoid breathing in dusty air, such as staying indoors when it is windy.”

In California, Valley Fever is found in portions of the Sacramento Valley, all of the San Joaquin Valley, desert regions, and portions of southern California. The annual number of reported cases of Valley Fever in California varies. In the past decade, the highest number (5,217) was reported in 2011. Since then, the incidence has declined. There were 2217 cases reported in 2014.

Valley Fever infection rates rose twelvefold nationwide from 1995 to 2009, according to the federal Centers for Disease Control and Prevention, and researchers estimate that the fungus infects more than 150,000 people each year who either suffer serious ailments without knowing the cause of their illness or escape detection of the disease.

While anyone can get Valley Fever, those most at-risk for severe disease include people 60 years or older, African Americans, Filipinos, pregnant women, and people with diabetes or conditions that weaken their immune system. People who live, work or travel in Valley Fever areas are also at a higher risk of getting infected, especially if they work or participate in activities where soil is disturbed.

LISTEN:  John Galgiani, MD, Professor of Medicine, University of Arizona, Director, Valley Fever Center for Excellence discusses Valley fever

The best way to reduce your risk of illness is to avoid breathing in dirt or dust in areas where Valley Fever is common. Stay inside and keep windows and doors closed when it is windy outside and the air is dusty. While driving, keep car windows closed and use recirculating air conditioning, if available. If you must be outdoors in dusty air, consider wearing an N95 mask or respirator. Refrain from disturbing the soil, whenever possible.

Related news: 

Valley fever risk studied in Washington state 

Pertussis incidence remains high in California, health officials urge prenatal vaccination 

California’s mandatory vaccination requirement: Public health versus personal liberty, where do you stand?