P-1593. Experience with a Rapid Diagnostic Blood Culture Identification Panel in Patients with Neutropenic Fever

Abstract Background Rapid identification of organisms in bloodstream infections can expedite selection of appropriate antimicrobials. This can significantly impact patient care, especially in immunocompromised hosts. Our retrospective study evaluates a single-center experience with a rapid diagnostic blood culture panel (BCID) in patients with neutropenic fever. Methods Between January 2020 and October 2023, all adult patients with neutropenic fever for whom blood cultures were obtained were reviewed. As standard protocol, a reflex BCID was performed with the FilmArray© panel for all blood cultures with microbial growth. We evaluated concordance between cultures and BCID data, and clinical implication of discrepant results. Patient demographics, cause of neutropenia, and 90-day mortality was documented. Results Of 6382 blood cultures in 1604 episodes for neutropenic fever, 253 unique blood cultures in 189 patients met criteria (Figure 1). Median age was 59 (SD±14.9) years, with 95 (50.3%) being female. A central venous catheter (CVC) was present in 75 patients (39.7%). The most common etiology for neutropenic fever was malignancy or chemotherapy in 124/189 (65.6%), followed by shock in 10/189 (5.3%). BCID identified resistance genes in 86/253 (34.0%) of samples, with mecA (64, 25.3%) and CTX-M (11, 4.3%) most commonly reported. BCID and routine susceptibility testing showed similar results in 219/253 (86.6%) specimens (Table 1). Of the discordant results, 9/31 BCID results missed presence of an on-target multi-drug resistant organism (Table 2). A change in therapy occurred based on BCID results from 143 (56.5%) of cultures in 94 (49.7%) of patients. There was no significant difference in 90-day mortality among patients where BCID led to an antibiotic change (37.2% vs 36.8%, p-value=0.96), and no difference in 90-day mortality among patients with discordant data (28.9% vs 37.5%, p-value=0.26). Conclusion In 239 episodes of neutropenic fever, BCID results correlated with routine results in 87% of blood cultures. BCID results resulted in quicker change to culture-appropriate antimicrobials in nearly half of the patients, however this was not associated with a mortality benefit. Disclosures All Authors: No reported disclosures