“As the temperatures warm up, and the western half of the U.S. stays quite dry, our desert-like soils will kind of expand and these drier conditions could allow coccidioides to live in new places,” Morgan Gorris, who led the GeoHealth study while at the University of California, Irvine, told Today.com.

As the infection continues to be diagnosed outside the Southwest, here’s what you need to know about valley fever.

What is valley fever?

Valley fever, which commonly occurs in the Southwest due to the region’s hot, dry soil, is an infection caused by inhaling microscopic spores of the fungus coccidioides. About 20,000 cases of valley fever were reported in 2019, according to the Centers for Disease Control and Prevention, and 97% of cases were reported in Arizona and California. Rates are usually highest among people 60 years of age and older.

While most people who breathe in the spores don’t get sick, those who do typically feel better on their own within weeks or months; however, some will require antifungal medication.

What are the symptoms of valley fever?

Symptoms of valley fever may appear anywhere from one to three weeks after breathing in the fungal spores and typically last for a few weeks to a few months. About 5% to 10% of people who get valley fever will develop serious or long-term lung problems. Symptoms include:

• Fatigue
• Cough
• Fever
• Shortness of breath
• Headache
• Night sweats
• Muscle aches or joint pain
• Rash on upper body or legs

How is valley fever diagnosed?

Valley fever is most commonly diagnosed through a blood test; however, health care providers may also run imaging tests, such as chest X-rays or CT scans, to check for valley fever pneumonia.

Who is most likely to get valley fever?

People who are at higher risk for becoming severely ill, such as those with weakened immune systems, pregnant people, people with diabetes, and Black or Filipino people, are advised to avoid breathing in large amounts of dust if they live in or are traveling to places where valley fever is common.

Is valley fever contagious?

No. “The fungus that causes valley fever, coccidioides, can’t spread from the lungs between people or between people and animals,” according to the CDC. “However, in extremely rare instances, a wound infection with coccidioides can spread valley fever to someone else, or the infection can be spread through an organ transplant with an infected organ.” 

How can I prevent valley fever?

While it’s nearly impossible to avoid breathing in the fungus coccidioides in places where it’s common, the CDC recommends avoiding spending time in dusty places as much as possible, especially for people who are at higher risk. You can also: 

• Wear a face mask, such as a N95 respirator
• Stay inside during dust storms
• Avoid outdoor activities, such as yard work and gardening, that require close contact with dirt or dust
• Use air filtration systems while indoors
• Clean skin injuries with soap and water
• Take preventive antifungal medication as recommended by your doctor

Is there a cure or vaccine for valley fever?

Not yet. According to the CDC, scientists have been working on a vaccine to prevent valley fever since the 1960s. However, researchers at the University of Arizona College of Medicine in Tucson have created a two-dose vaccine that’s been proved effective in dogs.

“I’m really quite hopeful,” Dr. John Galgiani, director of the Valley Fever Center for Excellence at the University of Arizona College of Medicine, told Today. “In my view, right now, we do have a candidate that deserves to be evaluated and I think will probably be effective, and we’ll be using it.”