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Coccidioidomycosis is an infection caused by inhaling the microscopic spores of the fungus Coccidioides immitis. Spores are the tiny, thick-walled structures that fungi use to reproduce. Coccidioidomycosis exists in three forms. The acute form produces flu-like symptoms. The chronic form can develop as many as 20 years after initial infection and, in the lungs, can produce inflamed, injured areas that can fill with pus (abscesses). Disseminated coccidioidomycosis describes the type of coccidioidomycosis that spreads throughout the body affecting many organ systems and is often fatal.


Coccidioidomycosis is an airborne infection. The fungus that causes the disease is found in the dry desert soil of the southwestern United States, Mexico, and Central and South America. Coccidioidomycosis is sometimes called San Joaquin fever, valley fever, or desert fever because of its prevalence in the farming valleys of California. Although commonly acquired, overt coccidioidomycosis is a rare disease. Chronic infections occur in only one out of every 100,000 people.

Although anyone can get coccidioidomycosis, farm laborers, construction workers, and archaeologists who work where it is dusty are at greater risk to become infected. People of any age can get coccidioidomycosis, but the disease most commonly occurs in the 25-55 age group. In its acute form, coccidioidomycosis infects men and women equally.

Chronic and disseminated forms of coccidioidomycosis occur more frequently in men and pregnant women. Although it is not clear why, people of color are 10-20 times more likely to develop the disseminated form of the disease than caucasians. People who have a weakened immune system (immunocompromised), either from diseases such as AIDS or leukemia, or as the result of medications that suppressed the immune system (corticosteroids, chemotherapy ), are more likely to develop disseminated coccidioidomycosis.

Causes and symptoms

When the spores of C. immitis are inhaled, they can become lodged in the lungs, divide, and cause localized inflammation. This is known as acute or primary coccidioidomycosis. The disease is not spread from one person to another. Approximately 60% of people who are infected exhibit no symptoms (asymptomatic). In the other 40%, symptoms appear 10-30 days after exposure. These symptoms include a fever which can reach 104°F (39.5°C), dry cough, chest pains, joint and muscle aches, headache, and weight loss. About two weeks after the start of the fever, some people develop a painful red rash or lumps on the lower legs. Symptoms usually disappear without treatment in about one month. People who have been infected gain partial immunity to reinfection.

The chronic form of coccidioidomycosis normally occurs after a long latent period of 20 or more years during which the patient experiences no symptoms of the disease. In the chronic phase, coccidioidomycosis causes lung abscesses that rupture, spilling pus and fluid into the lungs, and causing serious damage to the lungs. The patient experiences difficulty breathing and has a fever, chest pain, and other signs of pneumonia. Medical treatment is essential for recovery.

In its disseminated form, coccidioidomycosis spreads to other parts of the body including the liver, bones, skin, brain, heart, and lining around the heart (pericardium). Symptoms include fever, joint pain, loss of appetite, weight loss, night sweats, skin lesions, and difficulty breathing. Also, in 30-50% of patients with disseminated coccidioidomycosis, the tissue coverings of the brain and spinal cord become inflamed (meningitis ).


Many cases of coccidioidomycosis go undiagnosed because the symptoms resemble those of common viral diseases. However, a skin test similar to that for tuberculosis will determine whether a person has been infected. The test is simple and accurate, but it does not indicate whether the disease was limited to its acute form or if it has progressed to its chronic form.

Diagnosis of chronic or disseminated coccidioidomycosis is made by culturing a sample of sputum or other body fluids in the laboratory to isolate the fungus. A blood serum test is used to detect the presence of an antibody produced in response to C. immitis infection. Chest x rays are often used to assess lung damage, but alone cannot lead to a definitive diagnosis of coccidioidomycosis because other diseases can produce similar results on the x ray.


In most cases of acute coccidioidomycosis, the body's own immune system is adequate to bring about recovery without medical intervention. Fever and pain can be treated with non-prescription drugs.

Chronic and disseminated coccidioidomycosis, however, are serious diseases that require treatment with prescription drugs. Patients with intact immune systems who develop chronic coccidiodomycosis are treated with the drug ketoconazole (Nizoral) or amphotericin B (Fungizone). Patients with suppressed immune systems are treated with amphotericin B (Fungizone). Amphotericin B is a powerful fungistatic drug with potentially toxic side effects. As a result, hospitalization is required in order to monitor patients. The patient may also receive other drugs to minimize the side effects of the amphotericin B.

Patients with AIDS must continue to take itraconazole (Sporonox) or fluconazole (Diflucan) orally or receive weekly intravenous doses of amphotericin B for the rest of their lives in order to prevent a relapse. Because of the high cost of fluconazole, Pfizer, the manufacturer of the drug, has established a financial assistance plan to make the drug available at lower cost to those who meet certain criteria. Patients needing this drug should ask their doctors about this program.

Alternative treatment

Alternative treatment for fungal infections focuses on creating an internal environment where the fungus cannot survive. This is accomplished by eating a diet low in dairy products, sugars, including honey and fruit juice, and foods like beer that contain yeast. This is complemented by a diet consisting, in large part, of uncooked and unprocessed foods. Supplements of vitamins C, E, A-plus, and B complex may also be useful. Lactobacillus acidophilus and Bifidobacterium will replenish the good bacteria in the intestines. Antifungal herbs, like garlic (Allium sativum ), can be consumed in relatively large does and for an extended period of time in order to increase effectiveness.


Abscess An area of inflamed and injured body tissue that fills with pus.

Acidophilus The bacteria Lactobacillus acidophilus that usually found in yogurt.

Antibody A specific protein produced by the immune system in response to a specific foreign protein or particle called an antigen.

Antigen A foreign protein to which the body reacts by making antibodies.

Asymptomatic Persons who carry a disease but who do not exhibit symptoms of the disease are said to be asymptomatic.

Bifidobacteria A group of bacteria normally present in the intestine. Commercial supplements containing these bacteria are available.

Corticosteroids A group of hormones produced naturally by the adrenal gland or manufactured synthetically. They are often used to treat inflammation. Examples include cortisone and prednisone.

Immunocompromised A state in which the immune system is suppressed or not functioning properly.

Meningitis An inflammation of the membranes surrounding the brain or spinal cord.

Pericardium The tissue sac around the heart.


Most people who are infected with coccidiodomycosis only suffer from the mild, acute form of the disease and recover without further complications. Patients who suffer from chronic coccidiodomycosis and who have no underlying lung or immune system diseases also stand a good change of recovery, although they must be alert to a relapse.

The picture for patients with the disseminated form of the disease, many of whom have AIDS, is less positive. Untreated disseminated coccidiodomycosis is almost always fatal within a short time. With treatment, chance of survival increases, but the death rate remains high when meningitis or diffuse lung (pulmonary) disease is present. AIDS patients must constantly guard against relapse.


Because the fungus that causes coccidioidomycosis is airborne and microscopic, the only method of prevention is to avoid visiting areas where it is found in the soil. Unfortunately, for many people this is impractical. Maintaining general good health and avoiding HIV infection will limit coccidioidomycosis to the acute and relatively mild form in most people.



American Lung Association. 1740 Broadway, New York, NY 10019. (800) 586-4872.

Canadian HIV/AIDS Clearinghouse. 1565 Carling Avenue, Suite 400, Ottawa, ON K1Z 8R1. (877) 999-7740.

Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311.

National Aids Hotline. (800) 342-2437.

Project Inform. 205 13th Street, #2001, San Francisco, CA 94103. (800) 822-7422.

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coccidioidomycosis (kŏksĬd´ēoi´dōmīkō´sĬs), systemic fungus disease (see fungal infection) endemic to arid regions of the Americas, contracted by inhaling dust containing spores of the fungus Coccidioides immitis. From the respiratory tract, it can spread to the skin, bones, and central nervous system. Manifestions of the disease range from complete absence of symptoms to systemic infection and death. In 60% of the cases no clinical evidence of the disease is present and the only recognizable sign is a positive skin test; in 15% symptoms resembling those of influenza occur; and in 25% more serious signs such as swelling of the knees, weakness, pleural pain, and prostration occur. Diagnosis is made upon positive cultural identification of the fungus. Treatment is with the antifungal amphotericin B and bed rest. The soil that supports Coccidioides spores is indigenous to dry, hot geographical areas; the SW United States, Argentina, and Paraguay are areas of high incidence of infection. Cases in the San Joaquin Valley in California, where the disease is called valley fever, increased tenfold between 1991 and 1995.

See M. J. Fiese, Coccidioidomycosis (1958); D. A. Stevens, ed., Coccidioidomycosis (1980).

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Coccidioidomycosis (Valley Fever)

Coccidioidomycosis (Valley Fever)

What Is Coccidioidomycosis?

Is Coccidioidomycosis Common?

Can Coccidioidomycosis Be Prevented?


Coccidioidomycosis (kok-sih-dee-oyd-o-my-KO-sis), also know as valley fever, is a disease that can occur after breathing in the spores* of a fungus found naturally in the soil of dry regions, such as the southwestern United States.

are a temporarily inactive form of a germ enclosed in a protective shell.


for searching the Internet and other reference sources

Coccidioides immitis

Desert rheumatism

Fungal infection

San Joaquin Valley fever

What Is Coccidioidomycosis?

During World War II, American trainees sent to Arizona and parts of southern California for flight training took thousands of days of sick leave because of coccidioidomycosis, a disease caused by Coccidioides immitis (kok-sih-dee-OYD-eez IH-mih-tus), a fungus that hibernates a few inches beneath semi-dry soil. The diseases other name, valley fever, comes from the San Joaquin Valley region of California, where the fungus was first identified.

After regular rainfall, the coccidioides fungus blooms into tiny mold spores. If the soil is stirred by events such as dust storms, earthquakes, farming, excavation, or construction work, these microscopic spores spring into the air, where they are easily breathed into the lungs of people and animals.

Coccidioidomycosis cannot be passed from person to person. People must inhale the spores of the fungus in order to contract the disease. Most people who inhale the spores develop only a mild case of disease, in which the infection results in symptoms similar to those of a cold or the flu that go away on their own. Many people are not even aware that they are infected when the symptoms are mild. For those with weakened immune systems and for people of African or Filipino ancestry (who, for some unknown reason, get more severe forms of the disease), coccidioidomycosis can be much more serious, spreading from the lungs to other parts of the body and even to the brain. Severe cases may result in meningitis*. Coccidioides infection that has spread throughout the body and occurs with arthritis* is sometimes called desert rheumatism (ROO-muh-tih-zum). In general, the more fungal spores inhaled by a person, the more serious the disease tends to be.

(meh-nin-JY-tis) is an inflammation of the meninges, the membranes that surround the brain and the spinal cord. Meningitis is most often caused by infection with a virus or a bacterium.
(ar-THRY-tis) refers to any of several disorders characterized by inflammation of the joints.

Is Coccidioidomycosis Common?

The fungus that causes coccidioidomycosis is found mainly in the desert climates of the southwestern United States, parts of Mexico, and Central and South America. The infection is considered endemic* in these regions. People who live in or visit cocci country and who often spend time outside for work or play are more likely to develop the disease, especially near areas of development and construction during the summer and fall. Up to 50 percent of people living in such areas have antibodies* against Coccidioides immitis in their blood, which indicates that they have been exposed to the fungus, although many of them never developed signs of the disease.

(en-DEH-mik) describes a disease or condition that is present in a population or geographic area at all times.
(AN-tih-bah-deez) are protein molecules produced by the bodys immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.

Signs and symptoms

About 60 percent of people infected by Coccidioides immitis develop no symptoms. When symptoms do occur, they are usually mild and include fever, aches, chills, headache, and tiredness. Those with weakened immune systems, such as people with AIDS, certain types of cancer, and diabetes, have a greater risk of developing a more severe form of the infection.


A doctor diagnoses coccidioidomycosis by culturing* a patients sputum* or by doing a skin test. If injecting the test material into the skin of the forearm causes a large circular welt to appear on the arm within 2 days, it is considered a positive test for the fungus. Blood tests may show antibodies to the fungus, which helps confirm the diagnosis. A chest X ray is sometimes taken to look for signs of infection or inflammation in the lungs.

(KUL-chur-ing) means subjecting to a test in which a sample of fluid or tissue from the body is placed in a dish containing material that supports the growth of certain organisms. Typically, within days the organisms will grow and can be identified.
(SPYOO-tum) is a substance that contains mucus and other matter coughed out from the lungs, bronchi, and trachea.


Most mild cases of the disease can be managed with bed rest, over-the-counter pain relievers such as acetaminophen (uh-see-tehMIH-noh-fen), and sometimes oral (by mouth) anti-fungal medication. In more serious cases in which the fungus has spread throughout the body, intravenous (in-tra-VEE-nus, or given directly into a vein) antifungal medicines and hospitalization may be necessary. Mild cases of coccidioidomycosis last about 2 weeks, but recovery may take up to 6 months in more severe cases.


Pneumonia*, arthritis, meningitis, and other serious problems can result if the infection spreads throughout the lungs or to other parts of the body, such as the liver, heart, brain, bones, or joints.

(nu-MO-nyah) is inflammation of the lung.

Can Coccidioidomycosis Be Prevented?

No specific activities can prevent a person from becoming infected with the coccidioides fungus, other than avoiding the regions where it is found. Planting grass and paving roads may reduce dust in problem areas but will not kill the fungus.

See also

Arthritis, Infectious

Fungal Infections





U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC offers information about coccidioidomycosis at its website.

Telephone 800-311-3435

U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894. The National Library of Medicine has a website packed with information on diseases (including coccidioidomycosis) and drugs, consumer resources, dictionaries and encyclopedias of medical terms, and directories of doctors and helpful organizations.

Telephone 888-346-3656

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