Sacramento, California - California Department of Public Health (CDPH) Director and State Health Officer Dr. Karen Smith is warning Californians to be aware of a potentially fatal infectious disease known as Valley Fever.

“Valley Fever is an ongoing concern in California and other areas of the Southwest United States,” Dr. Smith said. “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.”

August is designated as Valley Fever Awareness Month in California. Each year, the infection affects hundreds to thousands of people in the state with the highest rates reported from the southern Central Valley region including Fresno, Kern, Kings, Madera, Merced, and Tulare counties. Monterey and San Luis Obispo counties have also had high rates of reported cases.

Valley Fever, also known as coccidioidomycosis, or cocci, is caused by the spore of a fungus that grows in certain types of soil in the Southwest United States, and in some areas of Central and South America. People get infected by breathing in spores contained in dust that gets into the air when it is windy or when soil is disturbed, such as digging in dirt during construction or gardening.

Most people will not become ill and those who do may have flu-like symptoms that can last a month or more. Most people recover fully, but some will develop more severe disease, which can include pneumonia and infection of the brain, joints, bone, skin or other organs. If you think you might have Valley Fever, visit your health care provider as soon as possible.

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.

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.

It is difficult to predict the effect of the drought on Valley Fever. However, we do know that some climate factors, including rainfall amount, may influence the growth of the Valley Fever fungus in the soil, but they have not been consistently predictive of how many people get infected each year.

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.

The CDPH website has information about Valley Fever and how to protect against infection, including ways to prevent work-related Valley Fever.