| Coccidioidomycosis |
| Introduction |
Etiologic agent = Coccidioides immitis
Geographic distribution: The geographic distribution of this fungus is significantly different than that of Blastomyces and Histoplasma. Coccidioides is restricted to the "Lower Sonoran Life Zone" (semi-arid, alkaline soils) of the southwestern U.S. However, the pathogenesis is similar to blastomycosis and histoplasmosis in that infection follows inhalation of fungal elements (arthroconidia) from the soil. Infections may be associated with activities that disrupt the soil or create dust, as exemplified by outbreaks among persons attending a model plane flying competition in California in 2001 and workers at an archeologic site in Utah in 2001. The incidence of coccidioidomycosis in people has increased markedly since 1998 in Arizona. This seems to be related to climatic factors (prolonged drought periods with hot and dusty conditions).
Primary pulmonary infection occurs and, if the immune system cannot contain the infection at this level (either because of compromise or a large inoculum), then systemic disease can occur. However, COCCIDIOIDES IMMITIS INFECTIONS IN DOGS, CATS AND PEOPLE ARE OFTEN SUBCLINICAL! Recovered individuals appear to have life-long immunity.
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