coccidioidomycosis
(kok‵sid‵ē-oyd‵ō-mī-kō'sĭs 
)
[ Coccidioid(es) + mycosis ]
ABBR: cocci [colloquial]
Infection with any species of the genus Coccidioides. SYN: desert fever ; desert rheumatism ;.SYN: San Joaquin valley fever ; valley fever .
Usually infection is asymptomatic and requires no treatment. Affected patients are treated with long-term fluconazole, itraconazole, ketoconazole, or with amphotericin B; these drugs have a 50% to 70% success rate.
Incidence: Approx. 80% of people in the southwestern and western U.S. have positive skin test reactions, which identify those infected. The infection is common among migrant farm workers, construction workers, and others who disturb the soil. According to the Centers for Disease Control and Prevention about 20,000 clinically active cases of cocci are diagnosed each year.
Causes: Arthroconidia (spores from this fungus) circulate in the air when the soil is disturbed, e.g., during construction, dust storms, or earthquakes. Those who inhale the spores may develop active or subclinical infection.
Symptoms and Signs: In most people infection is asymptomatic and requires no treatment. In approx. 10% of patients, fever, cough, pleurisy, or rashes such as erythema multiforme occur. Granulomas may be seen on the chest x-ray of patients with fungal pneumonia. Systemic infection involving the skin and meninges occurs in less than 1% of patients. The disseminated form of coccidioidomycosis is more common in African-Americans and Asian-Americans, pregnant women, and the immunosuppressed, such as those who have received organ transplants or have HIV/AIDS.
Diagnosis: Diagnostic testing for the disease includes collecting blood, sputum, pus from lesions, and tissue for biopsy, using strict secretion precautions. An initial skin test also is administered, as both the primary and disseminated forms produce a positive coccidioidin skin test. A rising serum or body fluid antibody titer indicates dissemination. Additional testing may involve pleural, spinal, and joint fluid for the presence of antibodies. After diagnosis, serial skin testing, blood cultures, and serological testing are performed to help document the effectiveness of therapy. The patient is cautioned not to wash off the circle marked on the skin for serial testing, as it aids in reading test results.
Treatment: Most patients with primary infection recover without therapy. Patients with disseminated disease may be treated with intravenous amphotericin, or with a variety of azole antifungals, such as fluconazole or voriconazole.
Impact on Health: For primary infection, the prognosis is favorable. Disseminated disease is often fatal.
Patient Care: In mild primary disease, bedrest and adequate fluid intake are encouraged. The patient is monitored for shortness of breath. If arthralgia is present, prescribed analgesics are administered. Stand ard precautions are observed by health care professionals. If the patient has draining lesions, the patient and family are taught about strict secretion precautions, including the “no touch” dressing technique and careful hand hygiene. In central nervous system (CNS) dissemination, the patient is monitored closely for a decreased level of consciousness or a change in mood or affect.
Before intrathecal administration of amphotericin B, the procedure is explained to the patient, who is reassured that he or she will receive a local anesthetic before lumbar puncture. If the patient is prescribed amphotericin B intravenously, a test dose is administered as prescribed; if tolerated, the treatment dose is infused slowly (rapid infusion may result in circulatory collapse). The dosage (but not the rate) is increased gradually as prescribed. During the infusion, the patient's vital signs are monitored. Temperature may rise and the patient may experience shaking chills and hypotension 1 to 2 hr after the infusion is initiated, but these should subside within 4 hr after the infusion is completed. Fluid intake and output are assessed, with any oliguria or anuria noted. Laboratory results are evaluated for elevated blood urea nitrogen and creatinine levels and hypokalemia. To ease adverse reactions to amphotericin B, antiemetics, antihistamines, and antipyretics or low doses of corticosteroids are administered as prescribed. The patient is warned to report immediately any hearing loss, tinnitus, dizziness, headache, blurred vision, diplopia, and breathing difficulty. Laboratory findings are also monitored for blood dyscrasias and liver failure. The patient is monitored for any seizures, cardiac arrhythmias, respiratory distress, hemorrhagic gastroenteritis, drug extravasation, and anaphylactoid reactions. The patient is informed that therapy may take several months, and the importance of cooperating with the treatment regimen and recommended follow-up studies is emphasized.