Valley Fever Is Spreading Through a Hotter, Drier Western US - WIRED

Jesse had a disease called valley fever.

Some 60 percent of valley fever cases produce no symptoms or mild symptoms that most patients confuse with the flu or a common cold.

And another 10 percent have severe infections—the disseminated form of the disease, when the fungus spreads beyond the lungs into other parts of the body.

The Centers for Disease Control and Prevention estimates that some 150,000 cases of valley fever go undiagnosed every year—and that’s likely just the tip of the iceberg, doctors and epidemiologists say.

The disease is endemic to certain geographic areas, and it’s technically considered an “emerging illness,” even though doctors have been finding it in their patients for more than a century, because cases have been sharply rising in recent years.

According to CDC data, reported valley fever cases in the US increased by 32 percent between 2016 and 2018.

In most states where the disease is endemic, public health departments have been slow to grasp and advertise the breadth and potential impact of the illness, experts say, and the federal government could be doing more to fund research into a cure or vaccine for the infection.

It was only a few years later that the Kern County Department of Public Health in California began investigating the causes of a common disorder called “San Joaquin fever,” “desert fever,” or “valley fever,” which got its name from the state’s Central Valley, where the disease was prevalent.

As doctors reviewed evidence from Kern County, they noticed commonalities between cases of valley fever there and the disease the Stanford student experienced.

They found that it is endemic to certain areas of the world, that the fungus that causes the disease lives in soil, that a majority of people infected by it are asymptomatic, and, crucially, that weather patterns and seasonal climate conditions have an effect on the prevalence of Coccidioides.

US counties where valley fever is endemic have an average annual temperature above 50 degrees Fahrenheit and get under 600 millimeters of rain a year.

“Once I did that, I found that by the end of the 21st century, much of the western US could become endemic to valley fever,” she said.

In a December 2018 bulletin, Ventura County health officer Robert Levin cast doubt on the connection between Cocci and wildfires.

“As health officer for Ventura County, I don’t see a clear-cut connection between wildfires and Cocci infections,” he said, noting that only one of the 4,000 firefighters who worked on the Thomas Fire in 2017 got valley fever.

Jennifer Head, a doctoral student at UC Berkeley who works for a lab studying the effects of wildfires on valley fever, hasn’t seen much evidence backing up such a connection either.

“The media talks a lot about wildfires and valley fever, and the general speculation is that wildfires will increase valley fever,” she said?

That means a wildfire that breaks out in an area that is endemic to valley fever won’t necessarily encounter a vein of Cocci fungi.

“If a fire happened to be where there was valley fever fungus in the soil, then that would be a risk,” Galgiani said.

Researchers speculate that a pattern of intense drought followed by intense rain may be driving the rise in valley fever cases.

“And after a period of rain it’s even worse.” Parsonnet sees the real-world consequences of that dry-wet cycle at Stanford, where she works at a referral center that sees patients with even worse valley fever than Jesse had—the really bad cases.

“We see really terrible disease with the fungus affecting their brains and their bones,” she said.

Parsonnet has been at Stanford for three decades, and over that time, she’s seen not only more valley fever cases, but more severe cases.

“In the last few years, I’ve been taking care of three or four valley fever patients at any given time,” she said.

Decades have come and gone since researchers first connected the dots between the Cocci fungus and valley fever.

Yet public awareness of what valley fever is and how it works, in addition to the medical know-how to tackle this disease, is still lacking, even in states where valley fever is prevalent.

“Many of the doctors who practice here learn medicine where the disease doesn’t exist, like in New York, for example,” Galgiani said.

One in five valley fever tests produce a false negative, said Steven Oscherwitz, an infectious disease doctor at Southern Arizona Infectious Disease Specialists.

But part of the blame also lies with states and the way their public health departments prioritize diseases.

Laurence Mirels, an infectious disease specialist in San Jose, California, who is affiliated with the California Institute for Medical Research, said that valley fever has long languished behind HIV, West Nile virus, typhoid fever, tuberculosis, and other communicable or vector-borne diseases in states’ list of public health priorities.

“The things that public health departments tend to focus on are things that can be transmitted and can increase exponentially if the source isn’t dealt with,” Mirels said.

Out of all the states in the US where valley fever is endemic, Arizona is best equipped to handle the rise in Cocci cases.

The state's Department of Health Services keeps close tabs on valley fever and regularly reports cases to the Centers for Disease Control and Prevention.

It also has programs to raise awareness of valley fever among Arizona residents.

“It’s the second- or third-most frequently reported public health disease in the state.

That’s not the case anywhere else in the country.” Other states like Utah, Texas, New Mexico, and Washington are also clocking rising rates of valley fever, but it may be some time before the disease poses a big enough risk to residents that public health departments in those states start dedicating significant time and resources to it.

But the Texas Department of State Health Services doesn’t even report valley fever cases to the CDC yet.

There’s evidence that that is already starting to happen in California, where valley fever is becoming an increasingly serious public health threat.

In an email to Grist, a spokesperson for the California Department of Public Health noted that valley fever cases in the state nearly tripled between 2015 and 2019, from roughly 3,000 cases to 9,000.

The Department of Public Health got funding from the CDC in 2012 to hire an epidemiologist to study fungal diseases in the state, and it launched a $2 million valley fever awareness campaign in 2018

“Imagine that you put ads up that say, ‘You’re going to catch this terrible disease if you come here, look at what it does to people,’” Oscherwitz said

“I think there’s been reluctance by politicians to advertise this disease because it might deter people from coming here,” said Mark Johnson, president of the Tortolita Alliance, a conservancy group in Arizona that advocates for better valley fever awareness

They should be doing everything in their power to make people aware of the disease.” Johnson, who contracted valley fever last year after retiring to Arizona, argued that if the state was really dedicated to protecting Arizonans from valley fever, it would run advertisements on TV, put up signs at airports, and send out brochures, especially to new residents

For him, valley fever is a distant, if terrible, memory now

And he recently moved to Las Vegas, an area where valley fever is endemic

It may only be a matter of time before we start thinking about fungus more often, Barker said