Describing the Utility of Fungal Blood Cultures in Patients Hospitalized at a Large Pediatric Academic Center

BACKGROUND: Routine blood cultures (BCs) are frequently obtained in hospitalized children with suspected infection. Although bacterial pathogens are the primary concern, fungal infections remain a consideration in high-risk populations, prompting clinicians to order fungal blood cultures (FBCs) in addition to routine BCs. However, given the prolonged incubation time and labor-intensive nature of FBCs, their incremental diagnostic value beyond routine BCs is uncertain. METHODS: We performed a retrospective, single-center study of hospitalized children aged 0-18 years at the Children's Hospital of Philadelphia between October 2015 and December 2022. Electronic health record data were used to identify all FBCs and associated BCs obtained during hospitalizations lasting ≥24 hours. Demographic and clinical characteristics, including admitting service, neutropenia status and presence of a central venous catheter, were collected. Culture results were grouped into diagnostic episodes by hospitalization. FBC results were compared with BCs obtained within 5 days to assess diagnostic yield and clinical utility, defined as identification of a unique organism leading to a change in clinical management. RESULTS: A total of 540 FBCs were ordered for 244 patients across 159,563 inpatient admissions, representing 296 diagnostic episodes. Patients were predominantly male, non-Hispanic, and White, with 28.7% younger than 1 year. Most diagnostic episodes occurred in oncology, hematology, transplant, critical care or surgical settings; 25.3% involved patients with central venous catheters and 17.2% with neutropenia. Fifty-four FBCs were positive, corresponding to 22 diagnostic episodes (7.4%). Most positive cultures grew fungal pathogens, commonly Candida parapsilosis, Trichosporon asahii and Candida albicans. Only 1 FBC identified an organism not detected on routine BCs, and this finding did not alter the management. CONCLUSIONS: Over 7 years, FBCs provided no additional clinically actionable information beyond routine BCs. These findings support diagnostic stewardship efforts to limit routine FBC use and clarify scenarios in which they may be beneficial.