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Disease: Valley fever

Coccidioidomycosis (valley or desert fever is a respiratory infection caused by the dimorphic soil fungus Coccidioides immitis (California) and C. posadasii (Arizona). The fungus is endemic to the warm, arid regions of central California, the southwest U.S. especially the Phoenix and Tucson areas, the northwest part of Mexico, and South America.

C. immitis is probably the most infectious of all fungi. According to the CDC, about 10-50% of the people living in endemic region will have evidence of exposure to Coccidioides. The incidence is around 9 cases per 100,000 population. Outbreaks of coccidioidomycosis do occasionally occur, particularly following earthquakes or other events that disturb large amounts of soil in endemic regions. Besides people, domestic and wild animals also suffer from coccidioidomycosis.

During October 8-12, a previously healthy, 51 year-old-man from Atlanta, Georgia had attended the world championship of model airplane flying in Lost Hills, California, located in Kern County in San Joaquin Valley. On October 25, the patient came to a local Atlanta hospital complaining of influenza-like symptoms that began 1 week after returning from Lost Hills.

He came to the hospital with a fever of 39°C and a history of night sweats, productive cough, and weight loss. A chest X ray showed diffuse nodular lung lesions in both lobes.

Antimicrobial drugs (amoxicillin/clavulanic acid and ciprofloxacin) and antituberculosis therapy (including isoniazid, rifampin, ethambutol, and pyrazinamide) were administered. Blood and sputum specimens were negative for bacteria; HIV antibody test results were negative, but the fever persisted. A follow-up chest film showed an excess of fluid in the left side of the pleural cavity (the fluid-filled space that surrounds the lungs).

A CT (computed tomography) scan of the patient’s chest showed collapse of the left lower lung with central necrosis (dead tissue). A pleural biopsy showed no evidence of malignancy, but heavy lymphocyte infiltration and a necrotizing inflammation were found. On December 17, 30 mg/day of the oral anti-inflammatory drug prednisolone were prescribed for intermittent fever. Biopsy material and cultures of blood samples taken at admission grew an unidentified mold, which was also isolated from the biopsy wound. The patient was discharged afebrile from the hospital on January 20.

On January 25, the patient returned to the hospital complaining of fever, with a disturbance in consciousness. Another CT scan of the brain revealed no obvious organic lesions. He was referred to the university hospital on January 26 for further examination.

After the patient was admitted, his fever persisted and respiratory distress worsened rapidly. He developed severe headache, seizures, and loss of consciousness.

The patient was transferred to the intensive care unit for aggressive management of acute respiratory disease syndrome and deterioration of renal function. A chest X ray showed coalescence of nodular shadows and almost complete destruction of bilateral lung regions. Meropenem (a bacterial drug used to treat meningitis and pneumonia), antituberculosis agents, and intravenous voriconazole (an antifungal drug used to treat invasive fungal infections), 200 mg every 12 hours, were administered.

Both the unidentified mold, which was sent to our hospital for futher identification, and a mold cultured from the previous biopsy wound at our hospital were identified as Coccidioides immitis by their characteristic gross and microscopic characteristics. Hematoxylin and eosin staining of the biopsied tissue showed many spherules, typical of a disseminated coccidioidomycosis infection.

A lumbar puncture was performed on January 30, cultures of cerebrospinal fluid (CSF) were negative for bacteria and fungi. After the diagnosis of disseminiated coccidioidomycosis, voriconazole was replaced by intravenous fluconazole, 400 mg/day. The patient’s intensive care course was complicated by Pseudomonas pneumonia and repeated episodes of upper gastrointestinal bleeding. Uncontrolled coccidioidomycosis meningigits was suspected, and amphotericin B treatment directly into the spinal cord was planned.

Unfortunately, the patient did not respond to therapy and died on February 16.

-Dr. Pommerville-

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