If you travel to or live in the southwestern United States, you could be at risk for Valley fever because of a fungus called Coccidioides that lives in the region’s desert soils. Spores from the fungus can become airborne and cause an infection when inhaled.
You can develop Valley fever any time of year, but you're at higher risk of infection in early summer and late fall, when the soil is dry. Wind, construction work and even digging with a shovel can release dust and fungal spores into the air, where they can stay aloft for long periods of time. Airborne spores can travel many miles, which means that anyone living in regions the spores can reach, including Tucson and Phoenix, can become infected, even if they aren’t exposed to a lot of dust.
Also known by coccidioidomycosis (its medical name), “desert rheumatism” or “San Joaquin Valley fever,” cases of the fungal infection have been climbing since 1997 and have doubled since 2014.
What are the common symptoms of Valley fever?
Symptoms of Valley fever typically appear weeks after infection. About two-thirds of people who are infected either show no signs of illness or develop mild, flu-like symptoms that don’t require medical care. Most people will not even realize they were infected. But some people who are exposed experience more severe symptoms that can require medical care.
John Galgiani, MD, infectious disease specialist at Banner – University Medical Center Tucson and head of the Valley Fever Center for Excellence at the University of Arizona College of Medicine – Tucson, said, “Only one out of three infections causes serious illness, which typically presents like pneumonia and makes people feel very sick, often for many weeks or several months.”
Typical Valley fever symptoms include:
- Chest pain
- Night sweats
- Skin rashes
- Joint aches
Even if you are only visiting the Southwest, or you’re a seasonal resident, it is still important to know the signs of Valley fever. That’s because symptoms may not appear until you leave the area, and health care providers in other parts of the country are less likely to recognize the infection as Valley fever.
“They may attribute your symptoms to severe flu, pneumonia or other conditions,” Dr. Galgiani said. “Delays in diagnosis often lead to unnecessary medical care for the wrong diagnoses like bacterial infections, COVID-19 or even cancer. In some people, delays allow the infection to spread.”
In a small percentage of all Valley fever infections, the fungus spreads beyond the lungs to the skin, bones or brain. Although this can happen to anyone, those with significant risk factors are people with weakened immune systems, such as people with organ transplants, AIDS or immunosuppressing treatments for rheumatologic diseases. These infections do not go away on their own and often require many years and sometimes life-long antifungal treatments. And frequently, people need one or more surgical procedures to get their infections under control.
How is Valley fever diagnosed?
If you think you might have Valley fever, talk to your doctor. A blood test can identify the fungus. Without testing, it’s not possible to tell whether you have Valley fever, bacterial pneumonia, COVID-19 or another disease with similar symptoms.
Chest x-rays often show abnormalities from Valley fever, but do not provide enough detail to distinguish the infection from other diseases.
How is Valley fever treated?
Most people don’t need treatment for Valley fever—your immune response takes care of the infection, although it often takes a long time for symptoms to completely resolve. Taking an oral antifungal drug like Fluconazole for three to five months might make some people recover faster, but studies haven’t proven this benefit.
“Many of the most long-lasting symptoms like fatigue and muscle aches are from the body’s immune response to the infection, possibly like the protracted symptoms following COVID-19, and these are not helped by antifungal medications,” Dr. Galgiani said. Physical therapy and reconditioning are often more effective in treating these symptoms.
Most of the time, prior infection makes people immune to Valley fever, but those with compromised immune systems may become reinfected.
How can you prevent Valley fever?
“Anyone can get Valley fever, including children. It’s a good idea to stay indoors during dust storms with your doors and windows shut. But that doesn’t guarantee you won’t get infected,” Dr. Galgiani said.
Knowing that living in or visiting the desert Southwest exposes you to Valley fever can help. That’s because if you know about Valley fever, you’re more likely to seek a diagnosis and receive proper treatment sooner. “Remembering that Valley fever is common here is very important,” Dr. Galgiani said.
Fortunately, Valley fever is not contagious. This means that if you have Valley fever you are not a risk to others, and if you’re in close contact with someone with Valley fever, there’s no need to take precautions.
What about Valley fever in your pets?
Valley fever can also infect animals, especially dogs. There are no guaranteed ways to prevent dogs from getting infected, although the risks can be minimized by reducing outdoor exposure and preventing them from digging.
The bottom line
Valley fever is a lung infection caused by a fungus that lives in desert soil. If you think you may have Valley fever, share your concerns with your doctor. If you need to connect with a health care professional to diagnose or rule out Valley fever, reach out to Banner Health.
Other useful articles
- What to Know About Valley Fever During the COVID-19 Pandemic
- Should I Be Worried About Pneumonia?
- Do I Really Need an Antibiotic?