what parts of the body does valley fever affect?
Valley Fever. Overview, Causes, & Risk Factors. Valley fever is an infection, usually in the lungs, caused by the fungus Coccidioides immitis. It is called valley fever because the fungus is commonly found in the soil of the valleys of the southwestern US, Mexico, and parts of Central and South America. What is going on in the body? Valley fever may cause a range of mild symptoms, and a mild lung infection. Or the infection may be severe and progressive, and spread throughout the body, which can be fatal. What are the causes and risks of the infection? Valley fever is caused by a fungus that thrives in the soil.