Inhalation of fungal conidia from dust in ambient air or generated by soil-disrupting human activities or natural disasters. Not transmitted from person to person.
Endemic in arid regions, including those in the southwestern United States. Outside the United States, coccidioidomycosis is endemic in parts of Central and South America. Travelers are at increased risk if they participate in activities that expose them to dust, such as construction, landscaping, mining, agriculture, archaeological excavation, military maneuvers, and recreational pursuits such as dirt biking.
The incubation period is 7–21 days. Most infections (60%) are asymptomatic. Symptomatic infection ranges from a self-limited influenzalike illness, characterized by fever, rash, muscle aches, dry cough, weight loss, and malaise, to primary pulmonary coccidioidomycosis, characterized by pneumonia with changes on chest radiography.
In rare instances, severe lung disease (such as cavitary pneumonia) or dissemination to the central nervous system, joints, bones, or skin may develop. People at increased risk for severe pulmonary disease are the elderly, those with diabetes or recent smoking history, and people of low socioeconomic status. People at increased risk for disseminated disease include African Americans and Filipinos, those with immunocompromising conditions (such as HIV), and pregnant women, particularly in the third trimester of pregnancy.
Best diagnosed by using serologic, histopathologic, and culture methods. Serologic tests are useful to confirm diagnoses and provide prognostic information.
Some experts recommend that people without risk factors for severe or disseminated disease do not require treatment, because the illness is self-limited; others propose treatment to reduce the intensity or duration of symptoms. People at high risk for dissemination should receive antifungal therapy when diagnosed with acute coccidioidomycosis. Additionally, people with severe acute pulmonary disease, chronic pulmonary infection, or disseminated disease should receive antifungal therapy. Depending on the clinical situation, azole antifungal agents (such as fluconazole or itraconazole) or amphotericin B may be used.
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