Valley fever is reaching epidemic proportions and researchers aren’t sure why.

The airborne fungal spores that cause the illness killed six Kern County residents in 2016 and infected 1,905 others, a 62 percent surge over the number infected the year prior. That makes 2016 the worst year for the respiratory disease since 2012, Kern County Public Health officials announced Wednesday.

And they can’t pinpoint the reason.

Although cases are at four-year highs, they’re still down from 2011, the height of the last epidemic, when 2,745 fell ill, Public Health Director Matt Constantine said. He’s concerned, however, that infection rates will continue spiking this year.

In an effort to stem the increasing number of cases, which have been rising for three years, Public Health officials rolled out a new campaign Wednesday, lighting up electronic billboards across town with messages intended to raise awareness. The billboards will stay up through August, which is valley fever awareness month.

The billboards feature images of an iconic 1973 dust storm that swept through the region and led to one of the worst epidemics of valley fever in Kern County history. The signs read: “Cough? Fever? Exhausted? Talk to your doctor. Get tested for valley fever.” Others warn residents to avoid outdoor activities on windy days.

“Even if we help one person, that’s an impact,” Constantine said. “It’s priceless.”

Valley fever, or coccidioidomycosis, is caused by windborne spores that people inhale. Most don’t get sick. But for immunocompromised people, the risk of developing symptoms is heightened. The respiratory disease causes flu-like symptoms, extreme fatigue, chills and night sweats. If left untreated, the spores can disseminate throughout the bloodstream and create complications that can lead to a lifetime of health problems, and even death.

The fungus that causes the disease is endemic to the southwestern United States, and very prevalent in Arizona. But despite only having one-twelfth of Arizona’s population and one-fourteenth its geographic size, Kern County — the most vulnerable county in California — had a third of Arizona’s number of infections.

Arizona officials recorded 54 valley fever-related deaths in 2016, Arizona Public Health Department officials said. Infections in the state, however, dropped to 6,180 in 2016, a nearly 19 percent decline over the previous year.

Dr. John Galgiani, director of the Arizona Valley Fever Center for Excellence, speculated last year that the drop in cases might have to do with a wet summer monsoon season stretching into September and October, the peak months for valley fever.

Experts have long predicted that weather patterns play a role when there’s an increase in cases. Wet winters that linger into March encourage the growth of the coccidioides fungus, and then dry summers provide the opportunity for it to spread into the air, increasing the risk of infection.

Although Kern County Public Health officials didn’t have a clear reason why cases surged in 2016, they didn’t discount weather patterns.

“It’s really difficult for us to predict kind of the cyclical nature that we’re seeing,” Constantine said. “Clearly there are weather-related impacts, but I’m unaware of a definitive reason why we see those changes. What matters, of course, is that it’s increased for the last three years and at a higher rate than it's been.”

Valley fever is known as an “orphan disease” because it has no vaccine and no medications have been developed specifically to fight it. It remains widely misunderstood and underestimated, even by those living in endemic regions.

It’s critical that health officials raise awareness among the public, including doctors responsible for diagnosing and treating the disease, Constantine said.

Rob Purdie, president of the nonprofit Valley Fever Americas Foundation advocacy group, got sick on New Year’s Eve a few years ago. A doctor misdiagnosed him with a sinus infection, and antibiotics didn’t help. Another doctor prescribed more antibiotics that did nothing. Then Purdie was misdiagnosed with cluster headaches. By the time doctors identified what was really ailing Purdie — valley fever — the cocci fungus had spread to his brain and turned into cocci meningitis, a rare and sometimes fatal form of the disease.

Doctors now inject anti-fungal medications through a port in his head — or, as Purdie refers to it, his “unicorn horn.” If Purdie had been accurately diagnosed early, the disease wouldn’t have progressed, he said.

“The only weapon we have in our arsenal is awareness,” Purdie said, praising the billboard campaign and noting past successes.

His foundation secured a grant in the mid-1990s for a billboard campaign related to vaccine research. A trucker traveling along the interstate saw the billboard and started wondering about a friend, who was hospitalized at the time in a Lancaster hospital with what doctors believed was pneumonia, Purdie said. It wasn’t. It was valley fever.

“He saved his life,” said Sandra Larson, a past president of the foundation. “Billboards work.”

Julie Solis, a Bakersfield woman whose husband, Juan, was misdiagnosed for months and, like Purdie, developed cocci meningitis, was emotional Tuesday night when she heard about the billboard campaign.

“I cried,” Solis said. “This is exactly what we’ve been needing.”

​Harold Pierce covers education and health for The Californian. He can be reached at 661-395-7404. Follow him on Twitter @RoldyPierce

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