Predictors of Time to Effective and Optimal Antimicrobial Therapy in Patients With Positive Blood Cultures Identified via Molecular Rapid Diagnostic Testing

Clinical Impact of the BIOFIRE Blood Culture Identification 2 Panel in Adult Patients with Bloodstream Infection: A Multicentre Observational Study in the United Arab Emirates

Rapid pathogen identification is key to the proper management of patients with bloodstream infections (BSIs), especially in the intensive care setting. This multicentre study compared the time to pathogen identification results in 185 patients admitted to intensive care with a confirmed BSI, using conventional methods (n = 99 patients) and upon implementation of the BIOFIRE^® Blood Culture Identification 2 (BCID2) Panel, a rapid molecular test allowing for the simultaneous identification of 43 BSI-related nucleic acids targets (n = 86 patients). The median time to result informing optimal antibiotic therapy was significantly shorter following the implementation of the BCID2 Panel (92 vs. 28 h pre vs. post BCID2 implementation; p < 0.0001). BCID2 usage in addition to conventional methods led to the identification of at least one pathogen in 98.8% patients vs. 87.9% using conventional methods alone (p = 0.003) and was associated with a lower 30-day mortality (17.3% vs. 31.6%, respectively; p = 0.019). This study at three intensive care units in the United Arab Emirates therefore demonstrates that, in addition to conventional microbiological methods and an effective antimicrobial stewardship program, the BCID2 Panel could improve the clinical outcome of patients admitted to the intensive care unit with a confirmed BSI.

Examining the clinical impact of rapid multiplex polymerase chain reaction-based diagnostic testing for bloodstream infections in a national cohort of the Veterans Health Administration

STUDY OBJECTIVE

Bloodstream infections (BSIs) are a significant cause of mortality. Use of a rapid multiplex polymerase chain reaction-based blood culture identification panel (BCID) may improve antimicrobial utilization and clinical outcomes by shortening the time to appropriate therapy and de-escalating antibiotics among patients on overly broad-spectrum empiric therapy. The effect of BCID on clinical outcomes across varying institutional antimicrobial stewardship program (ASP) practices is unclear. This study evaluated clinical outcomes associated with the "real-world" implementation of BCID in a national health system with varying ASP practices.

DESIGN

National, multicenter, retrospective, pre-post quasi-experimental study of hospitalized patients admitted from 2015 to 2020 to VHA facilities, which introduced the BCID for ≥1 year.

SETTING

United States Veterans Health Administration (VHA) hospitals with BCID.

PATIENTS

Hospitalized VHA patients with ≥1 blood culture positive for bacteria featured on the BCID panel.

INTERVENTION

Comparison of outcomes between the pre- and post-BCID implementation groups.

MEASUREMENTS

Outcomes evaluated included early antimicrobial de-escalation within 48 h, defined as reduction in antimicrobial spectrum scores, time to appropriate therapy, and 30-day mortality.

MAIN RESULTS

A total of 4138 patients (pre-BCID, n = 2100; post-BCID, n = 2038) met the study criteria. Implementation of BCID was associated with significant improvements in early antimicrobial de-escalation (34.6%: pre-BCID vs. 38.1%: post-BCID; p = 0.022), which persisted after adjusting for other covariates (adjusted risk ratio [aRR], 1.11; 95% confidence interval [CI], 1.02-1.20; p = 0.011). Median time to appropriate therapy was shorter in the post-BCID implementation group relative to the pre-BCID group (9 h: pre-BCID vs. 8 h: post-BCID, respectively, p = 0.005), and a greater percentage of patients received early appropriate antimicrobial therapy within 48 h in the post-BCID implementation group (91.7%: pre-BCID vs. 93.8%: post-BCID; p = 0.008). In the multivariable regression analysis, BCID implementation was significantly associated with a higher likelihood of appropriate therapy within 48 h (aRR, 1.02; 95% CI, 1.01-1.08; p = 0.020). There was no difference in 30-day mortality between groups overall (12.6% pre-BCID vs. 11.2% post-BCID; p = 0.211).

CONCLUSIONS

In a "real-world" clinical setting, the implementation of BCID was associated with clinical improvements in antimicrobial utilization. The BCID platform may serve as a useful adjunct for BSI management in facilities with ASP.

Impact of a laboratory developed phenotypic rapid susceptibility test directly from positive blood cultures on time to narrowest effective therapy in patients with Gram-negative bacteremia: a prospective randomized trial

Background

Antimicrobial susceptibility testing (AST) is often needed prior to antimicrobial optimization for patients with gram-negative bloodstream infections (GN-BSIs). Rapid AST (rAST) in combination with antimicrobial stewardship (AS) may decrease time to administration of narrower antibiotics.

Methods

This was a prospective, nonblinded, randomized trial evaluating the impact of a phenotypic rAST method vs conventional AST (cAST) in hospitalized patients with GN-BSI and source control. The primary outcome was time to narrowest effective therapy.

Results

Two hundred seventy-four patients were randomized and 205 underwent analysis (97 cAST, 108 rAST). Median (interquartile range [IQR]) time to susceptibility results was 23 hours shorter in the rAST group (cAST: 62 [59–67] hours vs rAST: 39 [IQR, 35–46] hours; P < .001). Median (IQR) time to narrowest effective therapy was similar between groups (cAST: 73 [44–138] hours vs rAST: 64 [42–92] hours; P = .10). Median (IQR) time to narrowest effective therapy was significantly shorter in a prespecified subgroup of patients not initially on narrowest therapy and during AS working hours (cAST: 93 [56–154] hours vs rAST: 62 [43–164] hours; P = .004). Significant decreases were observed in median (IQR) time to oral therapy (cAST: 126 [76–209] hours vs rAST: 91 [66–154] hours; P = .02) and median (IQR) length of hospital stay (cAST: 7 [4–13] days vs rAST: 5 [4–8] days; P = .04).

Conclusions

In patients with GN-BSI, rAST did not significantly decrease time to narrowest effective therapy but did decrease time to oral antibiotics and length of hospital stay. Rapid AST using existing microbiology platforms has potential to optimize patient outcomes.

Clinical Impact of the Expanded BioFire Blood Culture Identification 2 Panel in a U.S. Children's Hospital

The BioFire blood culture identification (BCID) panel decreases time to pathogen identification and time to optimal antimicrobial therapy. The BioFire blood culture identification 2 (BCID2) panel is an expanded panel with 17 additional targets and resistance genes; however, there are limited data on its impact in pediatric patients. We compared the BioFire BCID2 panel and the BCID panel by assaying BCID2 simultaneously with the current standard of care on 191 consecutive blood culture specimens at Children's Hospital Colorado. The primary outcome was equivalence, measured as percent agreement between the two panels and standard culture. The theoretical reduction in time to optimal therapy was calculated overall, with subanalyses performed on Enterococcus species and Gram-negative resistance genes. The percent agreement was equivalent between the two panels, with BCID at 98% (95% confidence interval [CI], 95 to 100%) and BCID2 at 97% (95% CI, 93 to 99%); the difference was 1.2% (95% CI, -0.8, 3.1%; P < 0.0001). There was not a significant reduction in time to theoretical optimal therapy with BCID2 compared to BCID for all cultures (reduction of 9 h, P = 0.3). Notably, 13 Enterococcus faecalis isolates were detected on BCID2, which would have resulted in a theoretical reduction in time to optimal antimicrobial therapy of 34 h (P = 0.0046). Five CTX-M genes were detected for enteric bacteria. The BioFire BCID2 panel had equal rates of detection compared to the BioFire BCID panel in pediatric patients. It had the advantage of detecting more organisms at the species level, and significantly reducing time to theoretical optimal antimicrobial therapy for Enterococcus faecalis. With the additional resistance genes, it also has the potential to impact care with earlier identification of resistant enteric pathogens. IMPORTANCE The BioFire BCID2 panel is an accurate panel that is equivalent to the BioFire BCID panel compared to standard culture. The BioFire BCID2 panel offers several advantages over the BioFire BCID panel, including enterococcal species identification, Gram-negative resistance gene detection, Salmonella identification, and the added mecA/mecC and SCCmec right extremity junction (MREJ) target for better Staphylococcus aureus and coagulase-negative Staphylococcus (CoNS) differentiation. Most importantly, it provides additional clinical impact with the potential to decrease the time to optimal antimicrobial therapy compared to the BioFire BCID panel, with likely further impact at institutions with a higher prevalence of Gram-negative resistance.

No Implementation Without Representation: Real-Time Pharmacist Intervention Optimizes Rapid Diagnostic Tests for Bacteremia at a Small Community Hospital

Background: Rapid diagnostic tests (RDTs) for bacteremia allow for early antimicrobial therapy modification based on organism and resistance gene identification. Studies suggest patient outcomes are optimized when infectious disease (ID)-trained antimicrobial stewardship personnel intervene on RDT results. However, data are limited regarding RDT implementation at small community hospitals, which often lack access to on-site ID clinicians. Methods: This study evaluated the impact of RDTs with and without real-time pharmacist intervention (RTPI) at a small community hospital with local pharmacist training and asynchronous support from a remote ID Telehealth pharmacist. Time to targeted therapy (TTT) in patients with bacteremia was compared retrospectively across 3 different time periods: a control without RDT, RDT-only, and RDT with RTPI. Results: Median TTT was significantly faster in both the RDT with RTPI and RDT-only groups compared with the control group (2 vs 25 vs 51 hours respectively; P < .001). TTT was numerically faster for RDT with RTPI compared with RDT-only but did not reach statistical significance ( P = .078). Median time to any de-escalation was significantly shorter for RDT with RTPI compared with both RDT-only (14 vs 33 hours; P = .012) and the control group (14 vs 45 hours; P < .001). Median length of stay was also significantly shorter in both RDT groups compared with the control group (4.0 vs 4.1 vs 5.5 hours; P = .013). Conclusion: This study supports RDT use for bacteremia in a small community hospital with ID Telehealth support, suggesting additional benefit with RTPI.