'Valley Fever' Cases Surge in California, Arizona Drought causing spread of fungus-laced spores By Rob Quinn, Newser Staff Posted May 6, 2013 3:56 AM CDT 16 comments Comments The fever is caused by a fungus that lives in soil in the southwestern US. (AP Photo/Lenny Ignelzi) (Newser) – Public health officials in arid parts of the American West are battling a huge rise in cases of a dust-borne disease many people have never heard of. Valley fever is contracted when people breathe in fungus-laced spores, and the drier, warmer conditions of recent years have contributed to an 850% rise in cases since 1998, mostly in Arizona and California, the AP reports. Around half of infections do not result in symptoms, which include mild to severe flu-like symptoms; but disability or death occurs in a small percentage of cases where the infection spreads from the lungs to other parts of the body. The outbreak has hit hardest in central California, where 3,000 inmates classed as vulnerable to infection were recently transferred out of two San Joaquin Valley prisons where the fever has killed dozens of people over the last few years. "Valley fever is a very common problem here, and it devastates people's lives," says the chief of infectious diseases at Kern Medical Center in Bakersfield. "But many patients don't know about it, and some physicians are only vaguely aware of it because half of our physicians come from out of state."