The weather helps drive the spread of an often-misdiagnosed infection, which kills as many as 1,000 people per year. Valley fever (coccidioidomycosis) is a lung infection caused by spores from the fungus Coccidioides, which lives in soil in the southwestern United States and south-central Washington state. A 2005 study of Coccidioidomycosis in Phoenix found that the disease is influenced by the local climate. The study concluded, "On average, peaks in exposure to the fungal spores occur in June