Pretransplant serologic testing for fungal infections in a large commercial health insurance database, United States.

Reactivation of latent fungal infections poses a substantial risk for solid organ transplantation (SOT) and hematopoietic cell transplantation (HCT) recipients. We describe receipt of pretransplant fungal infection testing in an exploratory analysis among patients in a large US commercial health insurance database. We identified patients who received an SOT or HCT during January 1, 2018-January 31, 2025, and evaluated testing practices for selected fungal (blastomycosis, coccidioidomycosis, cryptococcosis, histoplasmosis) and non-fungal infections (including hepatitis B virus [HBV], hepatitis C virus [HCV], HIV, cytomegalovirus [CMV], and tuberculosis) in the year before transplantation. In total, 8.9% of 11 362 SOT and 13.0% of 6 934 HCT recipients received pretransplant fungal testing. Among SOT recipients, Coccidioides antibody was the most frequent fungal test type (5.0%), with the highest rates in states with known endemicity (e.g., Arizona: 58.7%). Among HCT recipients, cryptococcal antigen testing was the most common fungal test type (5.2%). Testing rates for viral infections and tuberculosis were substantially higher compared with fungal infection testing: HBV (SOT: 65.1%, HCT: 73.4%), HCV (SOT: 55.8%, HCT: 71.1%), HIV (SOT: 45.5%, HCT: 66.3%), CMV (SOT: 41.7%, HCT: 65.9%), and tuberculosis (SOT: 38.0%, HCT: 16.8%). Pretransplant fungal infection testing was infrequently performed compared with recommended viral and tuberculosis screening, consistent with current guidelines. Further research to understand the clinical outcomes and cost-effectiveness associated with pretransplant fungal testing could help improve approaches for targeted screening.