'Superblooms of fungus': How climate change is making valley fever worse

"On a pain scale of one to 10, it was a 10," Scott Shirley recalled. "The worst pain I've ever felt."

It was June 2020, and Shirley, a winemaker in Paso Robles, California, knew something was terribly wrong. He was going about his daily business when he doubled over with severe abdominal pain and a 103-degree fever. A doctor in the emergency room told him his left lung had collapsed.

But what ailed Shirley, now 50, wasn't COVID-19: It was valley fever.

Officially known as coccidioidomycosis — or "cocci" for short — valley fever is a fungal infection that is transmitted in dust. In the United States, it has mostly plagued humans and animals in Arizona and California's San Joaquin Valley, where the illness was first described as "San Joaquin Valley fever" more than a century ago.

But a disease that was confined to the arid Southwest for decades appears now to be spreading, with new cases being reported in Washington, Oregon and Utah. At the same time, infection rates are increasing, particularly in California, where rates have since 2000.