Test Performance and Clinical Utility of the cobas® eplex Blood Culture Identification Fungal Pathogen Panel

Abstract Identifying fungi to the genus or species level provides valuable insight for guiding antifungal therapy. We evaluated the performance and clinical utility of the Roche cobas® eplex blood culture identification fungal pathogen panel (BCID-FP). Although used in fewer than 1% of patients with blood cultures drawn, BCID-FP identified fungal pathogens in over 96% of tested samples within 72 hours. Over a three-year period, BCID-FP demonstrated a positive percent agreement (PPA) of 91.7% compared to culture (n=327). PPA was 100% for C. auris, C. kefyr, C. krusei, C. tropicalis, C. parapsilosis and C. neoformans; slightly lower for C. albicans (90.3%) and C. glabrata (91.1%); and lowest for C. lusitaniae (55.6%) and Fusarium spp. (0%). To assess clinical impact, we compared patient records from pre-implementation (results withheld from providers; n=31) and post-implementation (results released; n=68). Compared to the T2Dx® Candida panel, BCID-FP showed superior accuracy (PPA 98.0% vs. 61.7%). It also reduced time to fungal identification by 1.36 days relative to culture (p 0.0001). Post-implementation, there was also a significant increase in infectious disease physician recommendations for antifungal de-escalation (39.7% vs. 16.1%; p=0.0219), typically shifting from micafungin to fluconazole in C. albicans and C. parapsilosis cases. However, no significant differences were observed in time to antifungal optimization, empiric therapy duration, length of stay, or mortality. While BCID-FP offers clear diagnostic advantages, timely implementation of expert recommendations remains essential to improving outcomes.