Broadcast date: 9/28/2017 Valley fever is on the rise in the southwestern United States . Also called coccidioidomycosis, it is a potentially fatal lung infection caused by a fungus found in the soil. The CDC finds about 10,000 U.S. cases have been reported each year, mostly from Arizona and California. Many members of the public and even the medical community are not familiar with this serious illness, and the lack of knowledge can delay diagnosis and treatment. Further complicating matters,