California music festival attendees hospitalized with dangerous fungal infection rapidly spreading across US

BAKERSFIELD, Calif. - More than 20,000 attendees at a California music festival might have been exposed to a dangerous fungal illness that's rapidly spreading across the country.

The California Department of Public Health (CDPH) is investigating five cases of Valley fever that occurred among people who traveled through Kern County to attend Lightning in a Bottle held May 22-27 at Buena Vista Lake, near the city of Bakersfield.

Three people have been hospitalized to date, but the state's top health officials said additional cases linked to attendance at the festival are possible.

Valley fever is not contagious, meaning it cannot spread from one person or animal to another. Symptoms include cough, fever, fatigue, difficulty breathing, and chest pain​, according to doctors. There are about 200 deaths a year due to the disease.

"Those are mostly people with severe immunocompromising illnesses underlying this infection," said Dr. Brad Perkins, chief medical officer at Karius, a company that provides advanced diagnostics for infectious diseases. "It can be a devastating infection in those people. That's pretty rare, fortunately."

Lightning in a Bottle attendees​ can visit the CDPH Valley fever survey website for more information and to share details about any illness.

What is Valley fever?

The infectious disease is caused by the Coccidioides fungus that grows in the soil and dirt in some areas ​of California.

"While most people exposed to this fungus do not develop Valley fever, the fungus can infect the lungs and cause respiratory symptoms, including cough, difficulty breathing, fever, and tiredness or fatigue," the CDPH reports.

In rare cases, the Valley fever fungus can spread to other parts of the body and cause severe disease. 

In the past, Valley fever outbreaks have been linked to breathing in dust and dirt at outdoor events and job sites in certain parts of California where Valley fever is common.

Valley fever is on the rise in California, according to the CDPH, with particularly high numbers of cases reported since last year, and is most comm​on in the San Joaquin Valley and Central Coast areas of California.  

Why is Valley fever spreading?

The increased number of cases are primarily associated with people migrating to areas like Arizona and California, and people traveling there for recreation, Perkins said.

"Many of those may be retirees or older adults that, one, have not been exposed to Valley fever in the past, and, two, maybe immune suppressed at higher risk for disease," he adds.

The climate crisis may be to blame as well. As heat increases, that may be facilitating the reproduction of the fungus in the soil in these areas.

"It's important to note that the entire western United States has some level of Valley fever, but it's much higher in the Phoenix region of Arizona and certain parts of the interior of California," Perkins said.

A study published in the journal GeoHealth estimated that the range of Valley fever could reach the border with Canada before the end of the century.