Coccidioidomycosis (cok-SID-EEOY-do-my-ko-sis) is a fungal infection that is also commonly called Valley Fever. It can occur in people with healthy or suppressed immune systems. In people with healthy immune systems, it usually causes mild or moderate lung problems. In people with suppressed immune systems, it can cause serious lung problems and can also spread to other organs, including the bones, joints, lymph nodes, kidneys, or skin. It can also cause disease of the central nervous system, which can be life-threatening if not diagnosed and treated promptly.

Coccidioidomycosis is caused by either of two related fungi, Coccidioides immitis and C. posadasii. These fungi are predominantly found in the Southwestern parts of the United States. This includes the central valley of California, Arizona, parts of New Mexico, and Texas west of El Paso. They can also be found in northern Mexico, parts of Central America, and Argentina.

People can become infected with C. immitis and C. posadasii upon breathing in soil or dust contaminated with the fungi. The highest risk of breathing in these fungi is usually during dust storms or natural disasters, most notably in the Southwestern United States. HIV-positive people with CD4 cells below 250 are at the highest risk of developing either mild or severe coccidioidomycosis after breathing in the fungus. Pregnant women and Black and Filipino men are also at a higher risk of developing active disease after being exposed to C. immitis or C. posadasii.


What are the symptoms and how is it diagnosed?

Most people who are infected with C. immitis or C. posadasii do not experience any symptoms of disease. When they do occur, they usually include fever, a productive cough, chills, headache, muscle aches, and sore throat.

The most effective way to diagnosis this infection is to collect fluids from the affected area, such as the lungs in someone with respiratory problems. Once these fluids have been collected, a laboratory will attempt to grow the fungus in test tubes. From there, a diagnosis can be confirmed.

It is possible to check blood samples for antibodies to C. immitis and C. posadasii. This is the preferred method of diagnosing people with healthy immune systems and in people with infection of the central nervous system. In people with HIV, particularly those with suppressed immune systems, antibody testing may not produce reliable results.


How is it treated?

People with healthy immune systems who are diagnosed with coccidioidomycosis don’t necessarily require treatment, as the symptoms are usually mild and clear up on their own. For people with compromised immune systems, coccidioidomycosis can be progressive and can cause serious respiratory distress and treatment is deemed necessary. Treatment is also required if coccidioidomycosis has spread beyond the lungs, to other organs and tissues in the body (especially the central nervous system).

If the infection is mild, causing minimal lung problems or not causing any symptoms (but with positive antibody tests), oral fluconazole (Diflucan) or itraconazole (Sporanox) at doses of 400 mg a day is recommended.

If the infection is causing moderate or severe lung problems, or the infection is causing disease elsewhere in the body, amphotericin B (Fungizone) is the recommended treatment. It is administered through an intravenous (IV) line, usually in a hospital, until the patient is feeling better. Amphotericin B can cause numerous side effects, including fever, chills, muscle pain, nausea, vomiting, kidney problems, potassium deficiency, decreased white blood cells, and anemia. Liposomal formulations of amphotericin B—which attach the drug to microscopic spheres of fat—are a possibility (but are not officially approved for the treatment of coccidioidomycosis), as they have been shown to be just as effective and somewhat less toxic than standard amphotericin B for the treatment of several types of fungal infections. Liposomal formulations include Abelcet, Amphotec, and AmBisome.

Amphotericin B and fluconazole or itraconazole are sometimes taken together to maximize treatment.

When the infection strikes the brain, causing meningitis, the preferred treatment is fluconazole at a dose ranging from 400 to 800 mg per day. Though fluconazole is preferred, other antifungal drugs have been used successfully, including itraconazole, voriconazole (Vfend) and posaconazole (Noxafil). In cases where the meningitis does not respond to treatment, amphotericin B is recommended.

After an initial course of treatment, either fluconazole or itraconazole is continued to prevent the coccidioidomycosis from recurring. Treatment may be discontinued after it has been taken for 12 months and the patient’s CD4 count is once again above 250 cells.

A syndrome—called immune reconstitution inflammatory syndrome (IRIS)—where antiretroviral treatment can actually exacerbate the symptoms of an opportunistic infection due to a strengthened immune response, has not been reported with coccidioidomycosis.


Can it be prevented?

For people living in Southwestern parts of the United States, there is no guaranteed way to prevent coccidioidomycosis from occurring, given that C. immitis is found in dirt and soil. However, HIV-positive people with compromised immune systems leaving in these areas should avoid activities involving prolonged exposure to dirt and soil, such as working on excavation sites or lingering in unfiltered areas during a dust storm.

Taking antifungal medications on a regular basis, in order to prevent coccidioidomycosis, may be recommended by your health care provider if you have antibodies to the fungi and your CD4 count is below 250. The recommended drugs in this case are 400 mg of fluconazole or 200 mg of itraconazole once-daily. Preventive treatment may be discontinued if your CD4 count remains above 250 for six months or longer.

Coccidioidomycosis is more likely to occur in HIV-positive people with compromised immune systems. Thus, one way to help prevent it from occurring is to keep the immune system healthy, such as by using anti-HIV drugs, reducing stress, eating right, and getting plenty of rest.

Are there any experimental treatments?

If clinical trials for HIV-positive patients with coccidioidomycosis are being conducted, they will most likely be listed on, a site run by the U.S. National Institutes of Health. The site has information about all HIV-related clinical studies in the United States. For more info, you can call their toll-free number at 1-800-HIV-0440 (1-800-448-0440) or email

Last Reviewed: January 18, 2016