Climate Tucson: Valley fever season is here
The fungal infection from spores in the dust attacks our lungs. Dogs get it too—and it can be fatal.
It's Valley fever season.
The fungus that causes the respiratory disease, delivered on the rising dust that covers everything in Tucson and Phoenix—the nation’s hot spots for the infection—is on the wing after the winter rains.
Rain feeds the growth of the spores that linger in the ground. When the soil dries and spring winds blow, up they go. Wind isn’t the only means of transport: kicking up dust on a hike or working at a construction site can also deliver the infection. All it takes is a deep breath of dust-infected air to deposit the miniscule spores that carry the disease into the lungs.
Humans and canines are the most susceptible, and dogs suffer the most from the fungal disease that can spread beyond the lungs.
Closer to the ground, dogs breathe in more of the spores more often and are three times more likely to get infected than humans, says veterinarian Lisa Shubitz, a research scientist with the Valley Fever Center for Excellence at the University of Arizona. “They’re closer to the ground.” Boxers, Dobermans, shepherds and most any kind of hunting dog are common victims.
“It’s heartbreaking to see them suffering," says Shubitz. And expensive to treat. She's heard of bills soaring up to $40,000 for treatments of beloved pets.
Not every doctor or vet can diagnose Valley fever
For humans, Valley fever can be cured with anti-fungal medication and bed rest. But it also can be debilitating and in extreme cases fatal. Early symptoms present like the flu or pneumonia, and likely include a nasty-looking rash.
Spores gather in the lungs, giving way to misdiagnoses of lung cancer or tuberculosis. Outside the infection zone, very few physicians or veterinarians would have the knowledge or the means to test for the presence of the disease. Outside its region, Valley fever, formally Coccidioidomycosis and nicknamed “cocci,” is an "exotic" disease.
“Even where Valley fever is common, like in Arizona, doctors very frequently forget to look for it. Fortunately, more than 90% of Valley fever patients get better without treatment, but for others, it can be debilitating, usually taking many weeks to months to go away," according to Dr. John Galgiani, founder and director of the Valley Fever Center.
There is no vaccine for Valley fever, though Galgiani and Shubitz are holding their breath as the U.S. Department of Agriculture continues to review what could be the first-ever vaccine for dogs.
A canine vaccine would be a promising gateway for human immunization. Galgiani believes the vaccine could be approved this year.
The vaccine got a boost with a $1 million investment to Anivive Lifesciences, which is developing the vaccines, from four-time Super Bowl champion Rob Gronkowski, who began his football career at the University of Arizona. Gronkowski told KGUN TV last April, “It's going to help so many. It's going to make happy and healthy pets out there.”
Until then, Galgiani and Valley fever researchers are spreading the word about a disease that is increasing making its presence known outside the primary infection zones.
“Cocci” kills 200 people a year
Once endemic in the U.S. only to central California and Arizona, which hosts the most infections, Valley fever is on the move across the western states as the heat of a changing climate and the loose soil that comes with a lingering drought—as well as ever-growing numbers of earth-disturbing building and housing sites—make conditions ripe for contracting the disease beyond its native landscape.
According to the CDC, Valley fever cases reported nationally rose from 2,271 in 1998 to 20,003 in 2019, most in Arizona and California, with a handful in New Mexico, Nevada and Utah.
Since 2000, Valley fever deaths throughout is native range increased from six people annually to an average of 200 a year leading up to 2022.
“We have definitely seen an increase in Valley fever cases in recent years,” says Galgiani. “We don't understand exactly why cases are increasing. It could be because we're getting better at diagnosing and reporting the disease. Or it could be environmental factors.”
The spread across the West represents a threat to 78 million people now and to those who move to the region in the coming decades. Its migration has not been lost on public health agencies and medical professionals.
If undiagnosed and untreated, Valley fever can be fatal to both humans and animals. And not just dogs. Cats and livestock, even marine mammals like sea lions swimming off the California coast have been tested positive for Valley fever after their bodies were found.
About one-third of people who are infected develop symptoms, says Galgiani, which take about 1 to 3 weeks to appear. He adds that symptoms can continue for weeks or months. In some patients, the infection can spread to the brain, skin or bones.
Among the most at risk, occupationally, are farm workers, archaeologists and construction workers, who tend to spend more time in the infected area. Movie sets have reported outbreaks. In 2013, 28 workers installing solar panels in California fell ill with the disease. Also at risk are people who are immunocompromised, pregnant, or over 60.
Dust storms are not the sole source of spore infection, but no one knows exactly where the fungus lives.
Research today is dismissing the idea that Valley fever is dispersed only by the wind. Tests of dust carried in monster dust storms in Phoenix, known as haboobs, found no Valley fever spores. In fact, no one knows exactly where the fungus lives. As Galgiani said in an Arizona State University news release, “ . . . just looking across the land we can’t tell which places the fungus grows or are the source of so many infections.” Work is ongoing on determining the lifestyle of this mysterious fungus.
Research is also questioning the “hot and dry-only” aspects of the disease. It is known that most cases of Valley fever are diagnosed after the rainy seasons in the infection areas, suggesting that the spores respond to dampness.
“We believe that the period of drying that happens after monsoon or good winter rains is necessary for the organism to mature and for those spores to become airborne,” Bridget Barker, an associate professor with Northern Arizona University’s Pathogen & Microbiome Institute, told KJZZ public radio.
Morgan Gorris, earth system and geohealth scientist with Los Alamos National Laboratory in New Mexico, believes the range is going to increase “substantially.” A Valley fever and West Nile disease specialist, Gorris was the lead author on a 2019 paper that projects Valley fever will be ensconced by century’s end in “the rain shadow of the Rocky Mountains and throughout the Great Plains.”
The disease has already been identified as far north as eastern Washington state. First diagnosed in Argentina in 1892 and found two years later in a Portuguese farm worker in California’s San Joaquin Valley — where it got its “valley” name — Gorris and others are testing to see if the spores of Coccidioidomycosis are sharing space in rodent burrows and being transported on the creatures like so many fleas.
She thought Valley fever was a thing of the past
For Chantel Dooley, Valley fever was a disease she had successfully fought at age 15. A resident of Phoenix, it took her a few months of rest to fully recover, though the fatigue, she says, stuck around for a while. “I had zero energy,” she remembers.
Nearly three years ago, then age 39, the Phoenix resident began in vitro fertilization treatments, but instead of getting pregnant she found herself a patient of Dr. Galgiani’s at the Valley Fever Center. It turns out that having had Valley fever does make one immune for life. With an exception: the disease stays dormant in the body — until it doesn’t.
Dooley’s in vitro did not work after multiple attempts. Following surgery on what was presumed to be endometriosis, she found out why; it was dumbfounding and disturbing. With no symptoms, no hint of infection from a disease she had already experienced, Dooley was told that her entire reproductive system was racked with Coccidioidomycosis spores. Her immune system had been compromised by the in vitro treatments, leaving her open to attack.
She was treated with fluconazole and recovered. While she can't complete the in vitro process, she excitedly said she had been approved to adopt a child.
“There are a lot of people out there sick from Valley fever,” she said. “It makes my heart hurt.”
More about Valley fever from the Arizona Department of Health Services.
ADHS stats, reports research on Valley fever
Download ADHS annual Valley fever report