Rapid diagnostic testing (RDT) allows for early adjustment of antibiotic therapy. This study examined the potential impact of a stewardship-driven antibiotic treatment algorithm, incorporating RDT into the management of Gram-negative bacteremia. The proposed algorithm would have resulted in 88.4% of cases receiving appropriate antibiotic therapy versus 78.1% by standard of care (P = .014).

Abdominal obesity is associated with gastroesophageal reflux disease (GERD) and Barrett's esophagus (BE). Increased body mass index (BMI) and waist-to-hip ratio (WHR) have been associated with BE. Abdominal diameter index (ADI, sagittal abdominal diameter divided by thigh circumference) was previously shown to be a more accurate predictor of incident cardiovascular disease compared to other measurements. Our aim is to examine whether abdominal diameter index was a more accurate predictor of prevalent BE compared to other anthropometric measurements. We conducted a case-control study of patients presenting to our institution. Our study population was consecutive Caucasian men with a known history of BE, and we recruited control patients who had GERD without BE. Both groups completed a questionnaire about demographics, smoking, and medications and underwent a series of anthropometric body measurements using standardized measuring tools. BMI, waist-to-hip ratio, and abdominal diameter index were calculated. Thirty-one BE patients and 27 control patients were recruited. The BE cohort were older and had a higher rate of hiatal hernia. The mean abdominal diameter index for patients with BE was 0.65 ± 0.07 and without BE was 0.60 ± 0.07 (p = 0.01). The predictive value of abdominal diameter index was analyzed using a receiver-operator characteristic (ROC) curve and was a more powerful predictor of BE than waist-to-hip ratio or BMI (AUROC = 0.70 vs. 0.60 vs. 0.52, respectively). Using a cut-point abdominal diameter index value of 0.60, abdominal diameter index had a sensitivity of 77.4% and a specificity of 63.0% for the presence of BE. When controlling for age, smoking status, and BMI, an abdominal diameter index ≥0.60 was a significant independent risk factor for BE (OR = 5.7, 95% CI = 1.29-25.4). In this pilot study, the abdominal diameter index appears to be a more powerful predictor of the presence of BE than BMI and waist-to-hip ratio and remained the only significant predictor of BE in multivariate analysis. We propose further validation of abdominal diameter index before inclusion in future prediction tools for BE.

Three RDT platforms (Verigene BC-GN, BioFire® BCID, and BCID 2 (RUO)) were compared using the Desirability of Outcome Ranking Management of Antimicrobial Therapy (DOOR -MAT) to evaluate potential downstream antimicrobial prescribing decisions resulting from the panels different organism and resistance detection. BioFire BCID (RUO) had the best mean DOOR-MAT scores.

Background: Decisions regarding which rapid diagnostic tests (RDT) for bloodstream infections to implement remains challenging given the diversity of organisms detected by different platforms. We used the Desirability of Outcome Ranking Management of Antimicrobial Therapy (DOOR-MAT) as a framework to compare two RDT platforms on potential desirability of antimicrobial therapy decisions. Methods: An observational study was performed at University of Maryland Medical System comparing Verigene Blood Culture (BC) to GenMark Dx ePlex Blood Culture ID (BCID) (Research Use Only) panels on blood cultures from adult patients. Positive percent agreement (PPA) between each RDT platform and Vitek MS was calculated for comparison of on-panel targets. Theoretical antimicrobial decisions were made based on RDT results, taking into consideration patient parameters, antimicrobial stewardship practices, and local infectious diseases epidemiology. DOOR-MAT with a partial credit scoring system was applied to these decisions and mean scores compared across platforms using paired t-test. Results: The study consisted of 160 unique patients. The Verigene BC PPA was 98.6% (95% CI 95.1, 99.8) and ePlex BCID PPA was 98% (95% CI 94.3, 99.6). Among the 31 organisms not on the Verigene BC panels, 61% were identified by the ePlex BCID Panels. The mean (standard deviation [SD]) DOOR-MAT score for Verigene BC was 86.8 (SD ± 28.5) versus ePlex BCID was 91.9 (SD ± 23.1), P = 0.01. Conclusion: Both RDT platforms had high PPA for on-panel targets. The ePlex BCID was able to identify more organisms than Verigene, resulting in higher mean DOOR-MAT scores.

BackgroundGram-negative bacteremia (GNB) is associated with significant morbidity and mortality, emphasizing the need for timely, effective antimicrobial therapy. In comparison to conventional diagnostic methods, Verigene® Blood-Culture Gram-Negative (VBC-GN) is a microarray rapid diagnostic test that identifies eight target GN organisms and six genetic resistance determinants. This study examined the potential clinical impact of VBC-GN coupled with a proposed antimicrobial stewardship (AMS)-derived treatment algorithm to guide timely, appropriate antimicrobial therapy in GNB.MethodsRetrospective, single-center, study of adult patients (≥ 18 years) with GNB at University of Maryland Medical Center (UMMC) from September 2015 – May 2016. Patient clinical characteristics, co-morbidities, and antimicrobials administered were collected. Appropriateness of antimicrobial therapy was by in vitro susceptibility. Appropriateness of actual empiric antimicrobials received as standard care were compared with theoretical antimicrobials as guided by the UMMC AMS treatment algorithm. Two investigators (KCC and ELH) independently evaluated appropriateness of empiric and algorithm antimicrobial recommendations.Results188 patients (median age 57.0 (IQR 46.5 – 65.0) years) with GNB were included and 143 (76.1%) were positive for target GN organisms. Eight (4.3%) cases were GN polymicrobial, 8 (4.3%) were CTX-M positive. E. coli was the most common target GN organism (30.3%), and genitourinary was the most common source (29.3%). There was a good level of agreement between reviewers regarding appropriateness of empiric therapy (Kappa = 0.735) and algorithm recommendations (Kappa = 0.855). Overall, the proposed algorithm would have resulted in 88.4% of cases receiving appropriate antimicrobial therapy vs 78.1% actual empiric antimicrobials (P = 0.014). The AMS treatment algorithm would have resulted in 14.4% appropriate de-escalation, 4.8% inappropriate de-escalation, 5.3% appropriate escalation, and 16.0% unnecessary escalation.ConclusionProposed antibiotics by AMS-derived treatment algorithm applied in conjunction with rapid diagnostic testing would result in a significantly higher proportion of patients receiving appropriate antimicrobial therapy vs. standard care.Disclosures J. K. Johnson, Nanosphere: Grant Investigator, Grant recipient