The number of Coccidioidomycosis, or Valley fever cases are being reported as increased numbers during the first half of the year, according to Centers for Disease Control and Prevention (CDC) data.

Through week 27 of 2018, 7,237 cumulative cases have been reported, compared to 5,109 during the same period in 2017.

The vast majority of cases, 98 percent,were reported from two states–Arizona (4,134) and California (2,949).

In California, Kern County has reported the most cases, while in Arizona, Maricopa County has seen the most.

Valley Fever, also known as coccidioidomycosis, is caused by the spore of a fungus that grows in soil in parts of California, Arizona, and other areas of the southwestern United States. People get infected by breathing in spores present in dust that gets into the air when it is windy or when soil is disturbed, such as through digging during construction.

Coccidioides immitis arthroconidia Image/CDC
Coccidioides immitis arthroconidia
Image/CDC

A person can reduce the risk of infection by avoiding breathing in dirt or dust in areas where Valley Fever is common. In these areas, when it is windy outside and the air is dusty, stay inside and keep windows and doors closed. While driving, keep car windows closed and use recirculating air conditioning, if available. If you must be outdoors when it is windy and dusty, consider wearing a properly fitted mask (such as an N95 respirator mask, which is widely available in retail stores), and refrain from disturbing the soil whenever possible. Employers should train their workers about Valley Fever symptoms and take steps to limit workers’ exposure to dust.

Related: FDA ‘fast-tracks’ Valley fever treatment


Most infected people will not show signs of illness. Those who do become ill with Valley Fever may have symptoms similar to other illnesses, including influenza or bacterial or viral pneumonia, so Valley Fever is not always recognized. The flu-like symptoms can last for two weeks or more. While most people recover fully, some people are at risk for more severe disease or complications of Valley Fever such as pneumonia, infection of the brain, joints, bone, skin or other organs. People with an increased risk for severe disease include those 60 years or older, pregnant women, and people with diabetes or conditions that weaken their immune system. Additionally, African-Americans and Filipinos are at increased risk for severe disease, but the reason is unknown.

Image/Robert Herriman
Image/Robert Herriman