201. Utility of Incorporation of Beta-D-glucan Testing in Algorithms for Diagnosis and Treatment of Candidemia.
Authors: Zacharioudakis Ioannis , Zervou Fainareti , Marsh Kassandra L , Siegfried Justin , Yang Jenny , Decano Arnold , Dubrovskaya Yanina , Mazo Dana , Aguero-Rosenfeld Maria E 
Published: December 2022

Abstract

Background
Candidemia is a common hospital acquired infection that is associated with significant morbidity and mortality. The optimal strategy for diagnosis remains unknown.

Methods
We evaluated 2 distinct diagnostic strategies in hospitalized patients with suspicion of Candida bloodstream infection, namely strategy #1 that included simultaneous blood cultures and T2Candida and strategy #2 that included blood cultures, T2Candida testing and Beta-D-glucan (BDG). We examined the consistency with which each diagnostic algorithm led to changes in antifungal prescribing, the overall rate of antifungal utilization and patients’ clinical outcomes.
Flow Chart. Figure 1.

Results
Among 96 patients tested with strategy #1, 3 had a positive result. Of those 100% completed a 14-day antifungal course for candidemia or were on antifungals until hospital discharge. Of the 29 out 120 patients that tested positive with strategy #2, 55.2% received a complete 14-day course or were on antifungals until hospital discharge. The percentage of completed treatment increased to 75.0% and 80.0% when the threshold for BDG positivity was increased at 200 pg/ml and 500 pg/ml respectively. We observed a significant difference in the overall antifungal utilization with 268.5 days of antifungals per 1,000 patient days for strategy #1, as opposed to 371.9 days of antifungals for strategy #2, a 38.5% increase. Negative tests at both diagnostic strategies led to a similar rate of antifungal discontinuation 3 days after testing (36.8% and 37.0% for strategy #1 and #2 respectively). We did not find significant benefits in death and/or subsequent diagnosis of candidemia between the 2 diagnostic strategies. Sensitivity analyses performed based on indication for testing and severity of illness did not significantly alter results. Table 1.Characteristics of patients tested for suspicion of candidemia with the 2 diagnostic strategies.
Figure 2. Duration of antifungal therapy among patients with positive BDG at different thresholds A. BDG&lt;80 pg/ml, B. BDG&lt;200 pg/ml, C. BDG&lt;500 pg/ml.
Figure 3. Percentage of patients who were taken off antifungals within 3 days of testing for different BDG thresholds, BDG&lt;80 pg/ml, BDG&lt;200 pg/ml, and BDG&lt;500 pg/ml.

Conclusion
In summary, the addition of BDG in diagnostic algorithms for candidemia was interpreted variably by clinicians, was associated with a significant increase in antifungal utilization, and it did not appear to lead to measured clinical benefits for patients. Diagnostic strategies of common and serious infections that incorporate non-culture diagnostics need to be evaluated for added benefit. Table 2.Antifungal utilization among patients tested for suspicion of candidemia with the 2 diagnostic strategies.
Table 3. Outcomes among patients tested for suspicion of candidemia with the two different diagnostic strategies.

Disclosures
All Authors: No reported disclosures.