Every year, there are about 150,000 cases of Valley Fever, caused by the toxic soil-dwelling fungus Coccidioides immitis, which exists in the southwestern United States.  New Yorker staff writer Dana Goodyear talks about the fungus-caused illness and why there's been a remarkable increase in infections. Her article “Death Dust: The Valley-Fever Menace” appears in the January 20 issue of The New Yorker.