Coccidioidomycosis.

Coccidioides immitis is a dimorphic fungus primarily found in the soil in a limited region of the southwestern United States. When this fungus causes an infection (coccidioidomycosis), it is due to the spores being inhaled and causing an inflammation of the respiratory tract. In most cases, the infection is self-limiting and is controlled by cell-mediated immunity. In HIV-infected patients, it is thought that the infection may be newly acquired, or reactivated, from a former incident. Patients with a CD4 count under 250 are at highest risk for becoming infected, and may present with pneumonia, fever, weight loss, night sweats, cough, and dyspnea. The infection can also become disseminated, and upon autopsy, widespread disease is found in the majority of patients that die of coccidioidomycosis. Chest x-rays show a diffuse reticulonodular infiltrate, then diagnosis is made by culturing the organism. The treatment of choice for disseminated disease is amphotericin B and alternative therapies including itraconazole and fluconazole, with possible lifelong treatment necessary. There is no current evidence that coccidioidomycosis can be prevented by any of these drugs.