Coccidioidomycosis in Elderly Persons

Background. Coccidioidomycosis is a fungal infection acquired via inhalation of airborne fungal arthrospores of Coccidioides species in regions of endemicity in the deserts of the southwestern United States and northern Mexico. In recent years, the incidence of coccidioidomycosis has increased in areas of endemicity, and previous studies have found the highest incidence of coccidioidal infection in Arizona among persons in older age groups. Methods. We conducted a retrospective review of data for all patients with coccidioidomycosis who were treated at our institution that compared clinical manifestations of coccidioidomycosis in patients aged >= 60 years with those in patients aged <60 years. Results. We compared 210 patients aged >= 60 years with 186 patients aged <60 years. No significant differences were observed with regard to manifestations of coccidioidomycosis, even after adjustment for comorbid conditions, excluding immunosuppression. Regardless of age, when coccidioidal illnesses in immunosuppressed patients were compared with those in nonimmunosuppressed patients, immunosuppressed patients were significantly more likely to have extrapulmonary dissemination of infection, to require hospitalization, and to have progressive infection or to die of coccidioidomycosis. Univariate logistic regression identified immunosuppression as the only marker that increased risk of extrapulmonary dissemination of infection (odds ratio, 2.13; P = .05), hospitalization (odds ratio, 2.68; P < .001), and death (odds ratio, 8.39; P < .001). Multivariate analysis revealed that neither age nor an interaction of age and immunosuppression had a significant impact on coccidioidal manifestations. Conclusions. Coccidioidomycosis is a serious illness in all patients, but its different manifestations in older-aged persons, compared with those in younger-aged persons, may be related to immunosuppression rather than age alone.