If you don’t live in Arizona or California—or even if you do—you may not be aware of Valley Fever, a fungal infection that should be on everyone’s radar, especially if you travel out west as a sunbird for the dry heat.
One of the missions of the Valley Fever Center for Excellence at the University of Arizona is creating awareness about the disease: Too many people, providers and hospitals are in the dark, and that can lead to delays in diagnosis and, when needed, treatment.
It’s estimated that 20,000 Americans acquire Valley Fever in any given year, but there’s a good chance the real number is exponentially higher because it can be mild enough for many people to dismiss as a cold.
Valley Fever, or coccidioidomycosis, is a fungal infection in the lungs caused by inhaling airborne particles of the fungus Coccidioides. The fungus, which is thought to have originated a million years ago, grows naturally in the form of a mold a couple of inches below the surface of soil in certain parts of the United States and some other countries. One of the geographical regions that has the perfect environment for it to grow—soil structure, its minerals, and dry air—is Arizona, where half to two-thirds of all U.S. infections occur. About 7 million people live in the Valley Fever “corridor” between Tucson and Phoenix and face exposure.
Another endemic area is the San Joaquin Valley in California—the source of “valley” in the disease’s name. But it’s not isolated to those two regions as was previously thought. It’s being found in other areas of the U.S. with low rainfall and high summer and moderate winter temps, including California’s Central Valley and parts of Nevada, New Mexico, Texas, Utah, and Washington state. Cases have also been reported in Mexico, as well as Central and South America.
The fungus is released into the air in the form of spores when soil is disturbed, such as when construction workers do excavation or firefighters create a land barrier to stop the spread of wildfires.
Someone who simply digs around their home to plant a tree or who happens to be outside when the spores get a ride on the wind can potentially breathe them in. At just 3 microns in size, these spores are not visible to the naked eye.
For many people, Valley Fever symptoms can be vague or even nonexistent. Or they can be dismissed as a cold or the flu—fatigue, night sweats, a cough, chest pain, headache. But it can be serious enough that you’re coughing up blood, losing weight, are too tired to get out of bed, and experience a red, itchy, tender rash, sometimes appearing as raised welts on the legs.
Thinking it’s eczema or an allergic reaction, some people go to their dermatologist or allergist. Sometimes these practitioners can connect the dots, but others aren’t aware of Valley Fever and don’t know to consider it, even when a patient mentions that they’ve also had a cough.
How a given person is affected by exposure to Valley Fever depends on their immunity level. Roughly 60 percent of those who contract it don’t have symptoms or have symptoms so mild that they dismiss them. While they might not need treatment at the time, the infection can stay in their body and get reactivated under certain circumstances, such as taking medication for an autoimmune disease or having an organ transplant. Another 30 percent of people develop noticeable symptoms, like pneumonia and fatigue so severe they can’t get out of bed. About 10 percent get so sick they need to be hospitalized. Some develop what’s called dissemination—when the fungus moves out of the lungs and into the bloodstream and travels in the body. This can lead to a form of meningitis, a bone infection or greater skin involvement. Studies show that any organ can be affected.
Valley Fever doesn’t discriminate. Yes, we see it in people who are immunocompromised—they already have some immune deficiency, perhaps cancer or HIV/AIDS, are on chemotherapy or a biologic, or have had a bone marrow or solid organ transplant. Many people with diseases that affect joints, like rheumatoid arthritis, come to Arizona because the warm and dry conditions make them feel better, and if they’re on a biologic for their autoimmune disease, they’re at increased risk of infection.
But we also see it in people who are immunocompetent, meaning their immune system is intact, such as college recruits who come to the University of Arizona to play basketball or football. Otherwise healthy young people can get Valley Fever at such a severe level that they suddenly can’t get out of bed. We don’t yet know why this happens, but we’ve started to look at genetic mutations that could make people more susceptible to severe disease.
There is a blood test for Valley Fever. It has very high, positive predictive value, which means if it is positive you have your answer. But it also has a very low negative predictive value, which means if it’s negative ,you have not truly ruled out the disease.
Also, a first test can come back negative simply because it’s too early in the course of the disease to see an immune response. Early on, a CBC blood test might show a rise in eosinophils, the white blood cells that help fight off infection, providing an important clue. Repeating the Valley Fever test in four to six weeks is needed. But if you have a negative test yet are already showing Valley Fever symptoms, your doctor may start treatment.
One of the biggest problems we see, even in Arizona, is that people whose Valley Fever has caused pneumonia are mistakenly diagnosed just with the pneumonia and treated with antibiotics that are useless for Valley Fever—sometimes with two and three courses of antibiotics even though they don’t get any better.
Some people who present with headaches are misdiagnosed as having migraine. When providers aren’t aware of Valley Fever, between 43 and 46 percent of people with severe disease experience at least a month, if not longer, in getting the proper diagnosis.
Amphotericin B is the only fungicidal drug that can completely eradicate Valley Fever, but because it has severe side effects, it’s reserved for the most severe cases. Most people who need treatment—they have bloody sputum and a bad cough— are prescribed an antifungal medication such as fluconazole. These drugs suppress the growth of the fungus and give your body’s immune system time to gain control of the fungus. People with disseminated disease will stay on the antifungal for a very long time, perhaps for the rest of their lives.
While not everyone needs treatment, everyone needs to be diagnosed because it’s crucial to know if you were exposed to Valley Fever down the road, should you ever need to go on a biologic or have a transplant, for example. In these situations, certain precautions will need to be taken.
Wetting soil before doing any kind of digging may lower the risk of dispersing spores in the air. However, if you’re in a high-risk group, consider delegating any planting to somebody else in your household. Avoid being outdoors on days that are very windy or consider wearing a mask for certain activities outside.
It’s also essential that you advocate for yourself. If you’re back home from a trip to a high-risk area and develop symptoms such as extreme fatigue or a cough that just won’t go away, ask to be tested for Valley Fever. Get a second or even third opinion if needed.
And, of course, get informed. At the Valley Fever Center for Excellence website at vfce.arizona.edu, there is extensive information for both the public and the medical community—our goals include increasing awareness for everyone, and people can contact us directly. The CDC and the California Health Department are also excellent resources.
