Diagnosis of Coccidioidomycosis with Use of the Coccidioides Antigen Enzyme Immunoassay

Background. We have previously shown antigenuria in patients with coccidioidomycosis through use of the Histoplasma antigen enzyme immunoassay (EIA), and now we have developed a specific Coccidioides antigen EIA. Methods. The Coccidioides EIA uses antibodies to Coccidioides galactomannan. The sensitivity of the Coccidioides and Histoplasma EIAs was evaluated in patients with more-severe coccidioidomycosis, and the specificity of these EIAs was evaluated in patients with nonfungal infections, in patients with other endemic mycoses, and in healthy individuals. Results. Among patients in the present study, antigenuria was detected in 70.8 % of patients with coccidioi-domycosis with use of the Coccidioides EIA and in 58.3 % of patients with use of the Histoplasma EIA. Antigenuria was absent in 99.4 % of healthy individuals, patients with nonfungal infections, and patients with noninfectious conditions. Cross-reactions with other endemic mycoses were observed in 10.7 % of patients. Conclusions. The Coccidioides EIA has potential to be useful in the rapid diagnosis of more-severe forms of coccidioidomycosis. Coccidioidomycosis is a fungal infection caused by the dimorphic fungi Coccidioides immitis and Coccidioides posadasii, which are endemic to specific geographic lo