Abstract
BACKGROUND: Endemic mycoses are caused by the dimorphic fungi Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidiodes species. Histoplasmosis and blastomycosis are endemic in Minnesota, with travel to coccidioidomycosis endemic areas being common. Diagnosis is challenging, in part due to confusion regarding laboratory testing. In our institution, we have observed that fungal serologies are often ordered when such infections are suspected, but results rarely seem to affect management. We reviewed the impact of serologic testing on the management of a Midwest veteran population. METHODS: Retrospective, observational study of patients with any serologic testing for endemic mycoses performed from January2014 to December 2018 at the Minneapolis VA Health Care System. To focus evaluation on the utility of serologic testing, we excluded patients with fungal antigen testing. RESULTS: Of 127 patients tested, 62 (49%) had only serologic testing. Patients were predominantly males (95%) with a median age of 66 years (range 27–93). Nineteen (31%) were tested in the hospital and had a median stay of 8 days (range 1–48). Median Charlson score was 4 (range 0–12). Travel to an endemic area for coccidioidomycosis was frequent (27/62: 44%), with Arizona being the most common destination (20/27: 74%). Median illness duration was 30 days (range 1–720). Respiratory symptoms predominated (43/62: 69%), followed by nonspecific (6/62: 10%), neurologic (5/62: 8%), and musculoskeletal (2/62: 3%) symptoms. Five (8%) were asymptomatic. Abnormal imaging was common, with 27/62 (44%) patients having an abnormal chest radiograph (consolidation 15%, nodules 11%, and interstitial pattern 8%), and 44/62 (71%) having abnormal CT findings (nodules 55%, ground glass opacities 18%, and consolidation 15%). Six patients (10%) had positive serology, but antifungals were started only in one case. Fungal serology results impacted management in 19/43 (44%) patients seen in clinic, but in 0/19 tested as inpatients (P < 0.001). The most common action (16/19: 84%) was to cease diagnostic workup (table). CONCLUSION: Fungal serologies can be useful in patients evaluated in clinic who present with respiratory symptoms, abnormal imaging, and potential fungal exposure. Testing in hospitalized patients appears to offer little benefit. DISCLOSURES: All authors: No reported disclosures.