Coccidioidomycosis
Coccidioidomycosis (San Joaquin fever, valley fever) is infection caused by the fungus Coccidioides immitis that usually affects the lungs (see Section 4, Chapter 42).
The spores of Coccidioides can be found in soil in the southwestern United States, Central America, and South America. Farmers and others who work with soil are most likely to inhale the spores and become infected. People who become infected while traveling may not develop symptoms of the disease until after they leave the area.
Coccidioidomycosis occurs either as a mild lung infection that disappears without treatment (acute primary coccidioidomycosis) or as a severe, progressive infection that spreads throughout the body and is often fatal (progressive coccidioidomycosis). The progressive form is often a sign that the person has a weakened immune system, usually because of AIDS.
Symptoms and Diagnosis
Most people with acute primary coccidioidomycosis have no symptoms. If symptoms develop, they appear 1 to 3 weeks after the person becomes infected. The symptoms are usually mild and include a cough, fever, chills, chest pain, and sometimes shortness of breath. The cough may produce sputum and even occasionally blood. Some people develop "desert rheumatism"--inflammation of the surface of the eye (conjunctivitis) and joints (arthritis) and the formation of skin nodules (erythema nodosum).
The progressive form of the disease is unusual and may develop weeks, months, or even years after the acute primary infection. Symptoms include mild fever and losses of appetite, weight, and strength. The lung infection may worsen, causing increased shortness of breath. The infection also may spread from the lungs to the bones, joints, liver, spleen, and kidneys. Infection of the brain and the tissues covering the brain (meninges) is often chronic.
A doctor may suspect coccidioidomycosis if a person develops symptoms after living in or recently traveling through an area where the disease is common. Chest x-rays usually reveal abnormalities, but further testing (of blood, sputum, or pus samples) may be needed to confirm the diagnosis.
Prognosis and Treatment
Acute primary coccidioidomycosis typically goes away without treatment, and recovery usually is complete. However, some doctors prefer to treat the person if coccidioidomycosis affects the lungs. Oral fluconazole or intravenous amphotericin B is given to people with the progressive form of the disease. Alternatively, the doctor may treat the infection with itraconazole or ketoconazole. If a person develops meningitis (infection of the tissues covering the brain and spinal cord), intravenous fluconazole is given. Alternatively, amphotericin B may be injected into the spinal fluid. Untreated meningitis is always fatal. Although drug treatment can be effective in localized infections--for example, in the skin, bones, or joints--relapses often occur after treatment is discontinued. Treatment must therefore be continued for years, often for life.
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