The number of reported Valley fever cases set a record in California in 2016, with more than 6,000 infections. Also known as coccidioidomycosis, the disease is caused by airborne soil fungus that can cause meningitis and other serious health conditions.
That number jumped to 8,103 in 2017, an increase of more than a third — growth many experts link to climate change. This year could be the worst yet.
Most cases surface between September and November, but through August this year more than 5,000 cases were reported in California, putting the state on pace for a new record.
“We’re seeing a huge increase in new cases in the past two-and-a-half years. It’s striking,” said Ian McHardy, co-director of the Center for Valley Fever at the University of California, Davis. “We’re seeing double and triple the cases. It’s a catastrophic change, and it’s getting worse.”
The fungus typically infects the lungs after spores are inhaled (it is not contracted person-to-person), producing a persistent cough and chest pain or other flu-like symptoms that can require months of treatment. In some cases it can spread. It can be hard to diagnose because it can mimic those of other ailments, and in many people symptoms fade away on their own.
This fall, Gov. Jerry Brown signed three bills to help combat Valley fever. The current state budget includes $8 million for research and education, to keep more Californians from catching the infection and to foster better diagnoses so symptoms can be treated accurately.
Yet experts say the disease likely will continue to expand, with more people getting it in more areas of the state.
One reason, McHardy said, is climate change. More dust storms in California have spread the fungal spores beyond the Central Valley, where the infections traditionally have been concentrated.
“We know there’s a direct correlation between these dust storms and Valley fever, and we know climate change is increasing the extreme weather patterns here, including the dust storms,” he said.
Valley fever is no longer strictly a Valley phenomenon. It has spread north to Sacramento and west to the coast.
“(In places) like Monterey, Los Angeles and San Luis Obispo counties, where we don’t expect to find it, it’s becoming much more common,” McHardy said.
Because Valley fever can resemble the flu, many physicians outside of the Central Valley don’t consider it in their diagnoses, even though the blood test to identify it is inexpensive and simple. The federal Centers for Disease Control and Prevention estimated there are about 150,000 undiagnosed cases a year, and McHardy said he thinks the number is higher. r
Gorn wrote this story for CAL Matters, a nonprofit, nonpartisan news venture focused on policy and politics in California.