Impact of antimicrobial stewardship intervention on coagulase-negative Staphylococcus blood cultures in conjunction with rapid diagnostic testing

Impact of BioFire® Blood Culture Identification (BCID) panels on antibiotic management of bacteremia due to select organisms

The purpose of this study was to assess changes in time to optimal therapy (TTOT) for bacteremia due to select organisms after implementation of the BioFire® FilmArray® blood culture identification panels at two community teaching hospitals. TTOT (days) was similar in Pre-BCID compared to BCID1 and BCID2 [(2.48 vs. 2.65, p=0.10); (2.48 vs. 2.37, p=0.27)]. There were no significant differences in time to effective antimicrobial therapy between groups. However, there were significantly more therapy changes and appropriate carbapenem use within 24 hours of the Gram stain result for gram-negative organisms in the BCID2 arm compared to the Pre-BCID arm. Additionally, a significant reduction in the duration of vancomycin for gram-positive organisms was noted in the BCID2 arm compared to the Pre-BCID arm. These findings suggest that the incorporation of the BCID2 panel resulted in changes in prescribing practices, leading to more appropriate antimicrobial utilization in a subset of patients.

Approaches to Reduce Use and Duration of Anti-MRSA Agents for Antimicrobial Stewardship Programs: A Review of Recent Literature

Antimicrobial stewardship programs (ASPs) have the potential to effectively deescalate unnecessary methicillin-resistant Staphylococcus aureus (MRSA) coverage. This review summarizes literature published from 2014 through 2021 describing contemporary ASP methods and their resulting effectiveness at reducing anti-MRSA agent use (ie vancomycin, linezolid, daptomycin, ceftaroline, and clindamycin). This review of the literature examined the following strategies, which had reports of success in either decreasing the use or duration of anti-MRSA agents: prospective review and feedback, antibiotic timeouts, health system or department protocol changes, polymerase chain reaction (PCR) and rapid testing of patient samples. Most of the current literature continue to support most ASP interventions including antibiotic timeouts, pathways, and molecular testing including MRSA nasal PCRs and rapid diagnostic testing can be successful at reducing unnecessary anti-MRSA use.

Impact of Blood Culture Contamination on Antibiotic Use, Resource Utilization, and Clinical Outcomes: A Retrospective Cohort Study in Dutch and US Hospitals

Background

Blood culture contamination (BCC) has been associated with prolonged antibiotic use (AU) and increased health care utilization; however, this has not been widely reevaluated in the era of increased attention to antibiotic stewardship. We evaluated the impact of BCC on AU, resource utilization, and length of stay in Dutch and US patients.

Methods

This retrospective observational study examined adults admitted to 2 hospitals in the Netherlands and 5 hospitals in the United States undergoing ≥2 blood culture (BC) sets. Exclusion criteria included neutropenia, no hospital admission, or death within 48 hours of hospitalization. The impact of BCC on clinical outcomes-overall inpatient days of antibiotic therapy, test utilization, length of stay, and mortality-was determined via a multivariable regression model.

Results

An overall 22 927 patient admissions were evaluated: 650 (4.1%) and 339 (4.8%) with BCC and 11 437 (71.8%) and 4648 (66.3%) with negative BC results from the Netherlands and the United States, respectively. Dutch and US patients with BCC had a mean ± SE 1.74 ± 0.27 (P < .001) and 1.58 ± 0.45 (P < .001) more days of antibiotic therapy than patients with negative BC results. They also had 0.6 ± 0.1 (P < .001) more BCs drawn. Dutch but not US patients with BCC had longer hospital stays (3.36 days; P < .001). There was no difference in mortality between groups in either cohort. AU remained higher in US but not Dutch patients with BCC in a subanalysis limited to BC obtained within the first 24 hours of admission.

Conclusions

BCC remains associated with higher inpatient AU and health care utilization as compared with patients with negative BC results, although the impact on these outcomes differs by country.

Impact of Rapid Identification and Stewardship Intervention on Coagulase-Negative Staphylococcus Bloodstream Infection

We investigated the impact of rapid diagnostic testing with and without algorithm-based stewardship recommendations on antibiotic use for bloodstream infection with coagulase-negative staphylococci. A significant reduction in antibiotic days of therapy was achieved in the stewardship intervention group that was not seen with rapid diagnostic testing alone.

Rapid Diagnostic Test Value and Implementation in Antimicrobial Stewardship Across Low-to-Middle and High-Income Countries: A Mixed-Methods Review

Despite technological advancements in infectious disease rapid diagnostic tests (RDTs) and use to direct therapy at the per-patient level, RDT utilisation in antimicrobial stewardship programmes (ASPs) is variable across low-to-middle income and high-income countries. Key insights from a panel of seven infectious disease experts from Colombia, Japan, Nigeria, Thailand, the UK, and the USA, combined with evidence from a literature review, were used to assess the value of RDTs in ASPs. From this, a value framework is proposed which aims to define the benefits of RDT use in ASPs, separate from per-patient benefits. Expert insights highlight that, to realise the value of RDTs within ASPs, effective implementation is key; actionable advice for choosing an RDT is proposed. Experts advocate the inclusion of RDTs in the World Health Organization Model List of essential in vitro diagnostics and in iterative development of national action plans.

Impact of the FilmArray Rapid Multiplex PCR Assay on Clinical Outcomes of Patients with Bacteremia

Bacteremia is a serious disease with a reported mortality of 30%. Appropriate antibiotic use with a prompt blood culture can improve patient survival. However, when bacterial identification tests based on conventional biochemical properties are used, it takes 2 to 3 days from positive blood culture conversion to reporting the results, which makes early intervention difficult. Recently, FilmArray (FA) multiplex PCR panel for blood culture identification was introduced to the clinical setting. In this study, we investigated the clinical impact of the FA system on decision making for treating septic diseases and its association with patients' survival. Our hospital introduced the FA multiplex PCR panel in July 2018. In this study, blood-culture-positive cases submitted between January and October 2018 were unbiasedly included, and clinical outcomes before and after the introduction of FA were compared. The outcomes included (i) the duration of use of broad-spectrum antibiotics, (ii) the time until the start of anti-MRSA therapy to MRSA bacteremia, and (iii) sixty-day overall survival. In addition, multivariate analysis was used to identify prognostic factors. In the FA group, overall, 122 (87.8%) microorganisms were concordantly retrieved with the FA identification panel. The duration of ABPC/SBT use and the start-up time of anti-MRSA therapy to MRSA bacteremia were significantly shorter in the FA group. Sixty-day overall survival was significantly improved by utilizing FA compared with the control group. In addition, multivariate analysis identified Pitt score, Charlson score, and utilization of FA as prognostic factors. In conclusion, FA can lead to the prompt bacterial identification of bacteremia and its effective treatment, thus significantly improving survival in patients with bacteremia.

Effect of Blood Culture Contamination on Antibiotic Use in an Institution With Rapid Laboratory Methods and Phone-Based Clinical Follow-up of Blood Culture Results

In a multivariate analysis of 30 574 blood culture (BC) results, BC contamination was associated with only a small increase in antibiotic length of therapy compared to no-growth BCs (difference, 0.36 days [95% confidence interval, .05-.67]; P = .02). Stewardship processes at our institution appear to be effective in reducing the impact of BC contamination.

MALDI-TOF mass spectrometry rapid pathogen identification and outcomes of patients with bloodstream infection: A systematic review and meta-analysis

There was inconsistent evidence regarding the use of matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) for microorganism identification with/without antibiotic stewardship team (AST) and the clinical outcome of patients with bloodstream infections (BSI). In a systematic review and meta‐analysis, we evaluated the effectiveness of rapid microbial identification by MALDI‐TOF MS with and without AST on clinical outcomes. We searched PubMed and EMBASE databases from inception to 1 February 2022 to identify pre–post and parallel comparative studies that evaluated the use of MALDI‐TOF MS for microorganism identification. Pooled effect estimates were derived using the random‐effects model. Twenty‐one studies with 14,515 patients were meta‐analysed. Compared with conventional phenotypic methods, MALDI‐TOF MS was associated with a 23% reduction in mortality (RR = 0.77; 95% CI: 0.66; 0.90; I² = 35.9%; 13 studies); 5.07‐h reduction in time to effective antibiotic therapy (95% CI: −5.83; −4.31; I² = 95.7%); 22.86‐h reduction in time to identify microorganisms (95% CI: −23.99; −21.74; I² = 91.6%); 0.73‐day reduction in hospital stay (95% CI: −1.30; −0.16; I² = 53.1%); and US$4140 saving in direct hospitalization cost (95% CI: $‐8166.75; $‐113.60; I² = 66.1%). No significant heterogeneity sources were found, and no statistical evidence for publication bias was found. Rapid pathogen identification by MALDI‐TOF MS with or without AST was associated with reduced mortality and improved outcomes of BSI, and may be cost‐effective among patients with BSI.

The Need for Dedicated Microbiology Leadership in the Clinical Microbiology Laboratory

Clinical microbiology laboratories play a crucial role in patient care using traditional and innovative diagnostics. Challenges faced by laboratories include emerging pathogens, rapidly evolving technologies, health care-acquired infections, antibiotic-resistant organisms, and diverse patient populations. Despite these challenges, many clinical microbiology laboratories in the United States are not directed by doctoral level microbiology-trained individuals with sufficient time dedicated to laboratory leadership. The manuscript highlights the need for medical microbiology laboratory directors with appropriate training and qualifications.

Impact of Accelerate Pheno and BacT/Alert Virtuo on Clinical Processes and Outcomes in Patients with Sepsis and Concurrent Gram-Negative Bacteremia

The Accelerate Pheno and BacT/Alert Virtuo systems may improve bacteremia management. Here, we evaluated the impact of both devices on outcomes in patients with sepsis and concurrent Gram-negative bacteremia. This quasiexperimental study included a retrospective preimplementation and a prospective postimplementation group. Patients ≥18 years old with Gram-negative bacteremia were included. Patients with neutropenia, pregnant patients, those who were transferred from an outside hospital with active bloodstream infections, and those with polymicrobial bacteremia were excluded. Blood culture incubation in the BacT/Alert 3D device and microdilution antimicrobial susceptibility testing from culture plate growth were used prior to implementation of the BacT/Alert Virtuo and Accelerate Pheno systems. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) identification directly from blood culture was used pre- and postimplementation. Time to Gram stain results, identification, susceptibility reporting, initiation of narrow-spectrum Gram-negative therapy at 72 h, 30-day inpatient mortality, sepsis resolution, and length of hospital stay were evaluated. A total of 116 patients were included (63 preimplementation, 53 postimplementation). Median times to Gram stain and susceptibility results were significantly shorter postimplementation (P < 0.001). The postimplementation group had an improved hazard ratio for narrow-spectrum Gram-negative therapy at 72 h (hazard ratio [HR], 2.685 [95% confidence interval {CI}, 1.348 to 5.349]), a reduced hazard ratio for 30-day inpatient mortality (adjusted HR [aHR], 0.150 [95% CI, 0.026 to 0.846]), and improved sepsis resolution (92.5% versus 77.8% [P = 0.030]). The length of hospital stay was unchanged after implementation. We conclude that implementation of the BacT/Alert Virtuo and Accelerate Pheno systems improved microbiology laboratory processes, antibiotic utilization processes, and clinical outcomes. These data support the use of rapid diagnostics in sepsis with concurrent Gram-negative bacteremia.

Mass Spectrometry and Microbial Diagnostics in the Clinical Laboratory

Over the past decade, matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry has revolutionized the practice of clinical microbiology and infectious disease diagnostics. Rapid advancement has occurred through the development and implementation of mass spectrometric protein profiling technologies that are widely available. Ease of sample preparation, rapid turnaround times, and high throughput accuracy have accelerated acceptance within the clinical laboratory. New mass spectrometric technologies centered on multiple microbial diagnostic markers are in development. Such new applications, reviewed in this article and on the near horizon, stand to greatly enhance the capabilities and utility for improved mass spectrometric microbial identification and patient care.

Genomic investigation of clinically significant coagulase-negative staphylococci

Introduction. Coagulase-negative staphylococci have been recognized both as emerging pathogens and contaminants of clinical samples. High-resolution genomic investigation may provide insights into their clinical significance.Aims. To review the literature regarding coagulase-negative staphylococcal infection and the utility of genomic methods to aid diagnosis and management, and to identify promising areas for future research.Methodology. We searched Google Scholar with the terms (Staphylococcus) AND (sequencing OR (infection)). We prioritized papers that addressed coagulase-negative staphylococci, genomic analysis, or infection.Results. A number of studies have investigated specimen-related, phenotypic and genetic factors associated with colonization, infection and virulence, but diagnosis remains problematic.Conclusion. Genomic investigation provides insights into the genetic diversity and natural history of colonization and infection. Such information allows the development of new methodologies to identify and compare relatedness and predict antimicrobial resistance. Future clinical studies that employ suitable sampling frames coupled with the application of high-resolution whole-genome sequencing may aid the development of more discriminatory diagnostic approaches to coagulase-staphylococcal infection.

Advances in rapid diagnostics for bloodstream infections

Septicemia from bloodstream infections (BSI) is the second largest cause of inpatient mortality and the single most expensive condition for US hospitals to manage. There has been an explosive development of commercial diagnostic systems to accelerate the identification and antimicrobial susceptibility testing (AST) of causative pathogens. Despite adoption of advanced technologies like matrix-assisted laser desorption imaging-time-of-flight mass spectrometry and multiplex polymerase chain reaction for rapid identification, clinical impact has been variable, in part due to the persistent need for conventional AST as well as prescriber understanding of these rapidly evolving platforms. Newer technologies are expanding on rapid detection of genotypic determinants of resistance, but only recently has rapid phenotypic AST been available. Yet, improved outcomes with rapid diagnostic platforms are still most evident in conjunction with active antimicrobial stewardship. This review will outline key advancements in rapid diagnostics for BSI and the role of antimicrobial stewardship in this new era.

Impact of rapid microbial identification on clinical outcomes in bloodstream infection: the RAPIDO randomized trial

OBJECTIVES

Bloodstream infection has a high mortality rate. It is not clear whether laboratory-based rapid identification of the organisms involved would improve outcome.

METHODS

The RAPIDO trial was an open parallel-group multicentre randomized controlled trial. We tested all positive blood cultures from hospitalized adults by conventional methods of microbial identification and those from patients randomized (1:1) to rapid diagnosis in addition to matrix-assisted desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) performed directly on positive blood cultures. The only primary outcome was 28-day mortality. Clinical advice on patient management was provided to members of both groups by infection specialists.

RESULTS

First positive blood culture samples from 8628 patients were randomized, 4312 into rapid diagnosis and 4136 into conventional diagnosis. After prespecified postrandomization exclusions, 2740 in the rapid diagnosis arm and 2810 in the conventional arm were included in the mortality analysis. There was no significant difference in 28-day survival (81.5% 2233/2740 rapid vs. 82.3% 2313/2810 conventional; hazard ratio 1.05, 95% confidence interval 0.93-1.19, p 0.42). Microbial identification was quicker in the rapid diagnosis group (median (interquartile range) 38.5 (26.7-50.3) hours after blood sampling vs. 50.3 (47.1-72.9) hours after blood sampling, p < 0.01), but times to effective antimicrobial therapy were no shorter (respectively median (interquartile range) 24 (2-78) hours vs. 13 (2-69) hours). There were no significant differences in 7-day mortality or total antibiotic consumption; times to resolution of fever, discharge from hospital or de-escalation of broad-spectrum therapy or 28-day Clostridioides difficile incidence.

CONCLUSIONS

Rapid identification of bloodstream pathogens by MALDI-TOF MS in this trial did not reduce patient mortality despite delivering laboratory data to clinicians sooner.

[Evaluation of Intervention by an Antimicrobial Stewardship Team for Patients with Bacteremia]

In this study, antimicrobial stewardship team (AST) intervention was evaluated by comparing patient outcomes and consumption of broad-spectrum antibiotics [carbapenem antibiotics and tazobactam/piperacillin (TAZ/PIPC)] before and after the intervention. There was no fluctuation in the consumption rate of carbapenem, TAZ/PIPC and other antibiotics, but there was a decreased annual consumption of antibiotics after AST intervention compared to before intervention. For the carbapenems, antimicrobial use density (AUD) of meropenem (MEPM) was highest in both periods, at 20.1 and 20.4 before and after AST intervention, respectively, with no significant change after AST intervention. However, the days of therapy (DOT) for MEPM were 27.4 and 24.8 d, respectively, with a decreasing trend after AST intervention. AUD and DOT for TAZ/PIPC after AST intervention were 6.5 and 8.1 d, respectively, which were lower than the pre-intervention values. Rapid identification of the causative strain enables early de-escalation and may improve the economics of antibiotic use, but there was no difference from before to after AST intervention. Compared with before and after strain identification, the carbapenem administration rate after AST intervention was significantly lower than the pre-intervention rate (p<0.01). There was no difference in 28-day mortality and treatment period before and after AST intervention, and there were no differences in outcomes such as resolution of bacteremia, mortality, exacerbation and no change from before to after AST intervention. Based on these results, we suggest that AST intervention can reduce consumption of antibiotics without altering patient outcomes.

Time to clinical response in sepsis associated with an algorithm for blood-culture pathogen identification using matrix-assisted laser desorption ionization time-of-flight mass spectroscopy

PURPOSE

Antimicrobial stewardship programs (ASPs) can be aided by using rapid diagnostics (RDT). However, there are limited data evaluating the impact of ASPs and RDT on sepsis outcomes in the setting of the new Sepsis-3 guidelines. This study evaluates the impact of a low-resource method for ASPs with RDT on sepsis outcomes.

METHODS

This was a prospective, quasi-experimental study with a retrospective double pretest. Patients ≥ 18 years old with sepsis and concurrent bacteremia or fungemia were included; patients who were pregnant, had polymicrobial septicemia or who were transferred from an outside hospital were excluded. In the first pretest (O1), polymerase chain reaction was used to identify Staphylococcal species from positive blood cultures, and traditional laboratory techniques were used to identify other species. Matrix-assisted laser desorption ionization time-of-flight mass spectroscopy and FilmArray were implemented in the second pretest (O2), and twice daily blood culture review was implemented in the posttest (O3).

RESULTS

A total of 394 patients (157 in O1, 176 in O2, 61 in O3) were enrolled. Clinical response was 73.2%, 83.5%, and 88.5% in O1, O2, and O3, respectively, p = 0.013. By Cox regression, the O3 was associated with improved time to clinical response (hazard ratio, 1.388; 95% confidence interval, 1.004-1.919) as compared with O1. Mortality, hospital length of stay, and intensive care unit length of stay were unchanged between groups.

CONCLUSION

Twice-daily blood culture review may be useful for implementing rapid diagnostics within low-resource ASPs. Further research is needed to identify the optimal method of blood culture follow-up within low-resource settings.

The Value Proposition for Pathologists: A Population Health Approach

The transition to a value-based payment system offers pathologists the opportunity to play an increased role in population health by improving outcomes and safety as well as reducing costs. Although laboratory testing itself accounts for a small portion of health-care spending, laboratory data have significant downstream effects in patient management as well as diagnosis. Pathologists currently are heavily engaged in precision medicine, use of laboratory and pathology test results (including autopsy data) to reduce diagnostic errors, and play leading roles in diagnostic management teams. Additionally, pathologists can use aggregate laboratory data to monitor the health of populations and improve health-care outcomes for both individual patients and populations. For the profession to thrive, pathologists will need to focus on extending their roles outside the laboratory beyond the traditional role in the analytic phase of testing. This should include leadership in ensuring correct ordering and interpretation of laboratory testing and leadership in population health programs. Pathologists in training will need to learn key concepts in informatics and data analytics, health-care economics, public health, implementation science, and health systems science. While these changes may reduce reimbursement for the traditional activities of pathologists, new opportunities arise for value creation and new compensation models. This report reviews these opportunities for pathologist leadership in utilization management, precision medicine, reducing diagnostic errors, and improving health-care outcomes.

Practical Guidance for Clinical Microbiology Laboratories: A Comprehensive Update on the Problem of Blood Culture Contamination and a Discussion of Methods for Addressing the Problem

In this review, we present a comprehensive discussion of matters related to the problem of blood culture contamination. Issues addressed include the scope and magnitude of the problem, the bacteria most often recognized as contaminants, the impact of blood culture contamination on clinical microbiology laboratory function, the economic and clinical ramifications of contamination, and, perhaps most importantly, a systematic discussion of solutions to the problem. We conclude by providing a series of unanswered questions that pertain to this important issue.

The Impact Of Pharmaceutical Interventions On The Use Of Carbapenems In A Chinese Hospital: A Pre-Post Study

Background

The challenge of drug resistance to carbapenems is of international concern with leading to increased hospital lengths of stay, costs, and mortality rates. How to get rid of the vicious cycle of drug resistance, new drugs, and re-resistance, and even the emergence of all-drug-resistant bacteria that humans cannot cope with, are the major challenges we face. To date, data about pharmaceutical interventions on the use of carbapenems are currently limited.

Patients and methods

A retrospective cohort study was conducted to compare pre- and post-intervention in Tongde Hospital of Zhejiang Province. Pharmaceutical interventions were performed in the post-intervention group, including real time monitoring of medication orders, educative group activities, and making interventions to physicians. Intervention acceptance and outcomes, including the length of hospital stay, readmission rates, 30-day mortality, and utilization of carbapenems, which was evaluated by the daily defined doses (DDDs), the days of therapy (DOTs), and the cost of carbapenems, were reviewed.

Results

During the study, 593 interventions were provided by clinical pharmacists with an average acceptance rate of 82.79%. Compared with the pre-intervention group, prescriptions of carbapenems for pathogen-directed therapy were improved significantly in the post-intervention group (59.27% vs 21.74%, p=0.022). The DDDs decreased from 281.96 to 174.28 and DOTs decreased from 9.19 to 5.18 after pharmaceutical intervention, and the pharmaceutical interventions had significantly lower mean total cost of carbapenems ($13,828.8 vs $8137.1, p=0.004) and length of hospital stay (9.3±1.5 vs 15.9±2.2, p=0.014). There was a significant reduction in 30-day mortality in the post-intervention group (9.46% vs 17.86%, p=0.013) while there were no differences found in the 30-day readmission (20.19% vs 20.66%, p=0.99).

Conclusion

Implementation of pharmaceutical interventions in our hospital successfully improved the appropriateness of carbapenem prescribing overall, and reduced the DDDs, DOTs, length of hospital day, and cost of carbapenems.

Direct Detection of Pathogens in Bloodstream During Sepsis: Are We There Yet?

Background

Advances in medicine have improved our understanding of sepsis, but it remains a major cause of morbidity and mortality. The detection of pathogens that cause sepsis remains a challenge for clinical microbiology laboratories.

Content

Routine blood cultures are time-consuming and are negative in a large proportion of cases, leading to excessive use of broad-spectrum antimicrobials. Molecular testing direct from patient blood without the need for incubation has the potential to fill the gaps in our diagnostic armament and complement blood cultures to provide results in a timely manner. Currently available platforms show promise but have yet to definitively address gaps in sensitivity and specificity.

Summary

Significant strides have been made in the detection of pathogens directly from blood. A number of hurdles, however, remain before this technology can be adapted for routine use.

The implementation of rapid microbial identification via MALDI-ToF reduces mortality in gram-negative but not gram-positive bacteremia

Our goals were to study the effect of rapid microbial identification (RMI) of positive blood culture on patient's outcome and to identify specific microbiological characteristics related to clinical benefit of RMI. This was a retrospective-cohort study of hospitalized, adult patients with bacteremia. The outcome of patients with bacteremia episodes was compared before vs. after the initiation of RMI. RMI was done by matrix-assisted laser desorption/ionization time-of-flight testing of microcolonies. The study included 1460 and 2710 cases in the pre- and post-intervention periods, respectively. There were similar rates of gram-negative, gram-positive, anaerobes, and polymicrobial infections, but higher rate of contaminants in the intervention period (39.9 vs. 43.7%, p = 0.019). The median time-to-identification decreased from 47.5 to 21.3 h (p < 0.001). Post-intervention, the median LOS declined from 10.83 to 9.79 days (p = 0.016), the rate of ICU transfer declined from 13.8 to 11.6% (p = 0.054), and the mortality rate declined from 20.9 to 18.3% (p = 0.047). The improvement in outcome variables remained statistically significant in multivariate analysis when performed for all episodes and non-contaminants but not for contaminants. The mortality declined in gram-negative bacteremia (20% vs. 15.5%, p = 0.005 in multivariate analysis) but not in gram-positive bacteremia (18.1% vs. 18.5%). RMI reduces mortality from gram-negative but not gram-positive bacteremia.

Clinical impact of matrix-assisted laser desorption ionization time-of-flight mass spectrometry for the management of inpatient pneumonia without additional antimicrobial stewardship support

We assessed whether implementation of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry without antimicrobial stewardship support would impact antimicrobial utilization and clinical outcomes in inpatient pneumonia. Implementation significantly reduced time to organism identification and time to optimal therapy but did not have a detectable impact on clinical outcomes.

Evaluation of rapid polymerase chain reaction-based organism identification of gram-positive cocci for patients with a single positive blood culture

For patients with a single-positive blood culture growing gram-positive cocci, organism identification can provide supportive information for differentiating contamination from infection. We investigated the effect of a rapid blood culture identification panel (BCID) on vancomycin-prescribing patterns and patient outcomes for single positive blood culture (PBC) growing gram-positive cocci. Adult patients with single-positive blood culture growing gram-positive cocci with conventional organism identification (pre-BCID) were compared with organism identification by BCID (post-BCID). Antimicrobial Stewardship Program (ASP) review of PBC was performed in both study groups. Vancomycin prescribing patterns were studied. Secondary endpoints were the incidence of nephrotoxicity, length of stay (LOS), readmission rate, mortality, and hospital costs. A total of 188 patients (86 pre-BCID, 102 post-BCID) were included. Organism identification was known 21 h sooner in the post-BCID group (P < 0.001). Coagulase-negative staphylococci were the most commonly isolated organisms (73%). In patients where vancomycin was deemed unnecessary (n = 133), vancomycin use (51% pre-BCID vs 36% post-BCID; P = 0.09) and time from culture positivity to vancomycin discontinuation (1.5 vs. 1.7 days; P = 0.92) did not differ between groups. We found no differences in the development of nephrotoxicity, LOS, readmission, mortality, or hospital costs. Earlier identification of single positive blood culture growing gram-positive cocci did not significantly influence prescribing patterns of vancomycin. However, baseline antimicrobial stewardship review of single positive blood culture growing gram-positive cocci may have lessened the opportunity for detectable differences. Larger studies, accounting for the impact of ASP intervention, should be performed to determine the value of each individual component.

Clinical impact of matrix-assisted laser desorption ionization-time of flight mass spectrometry combined with antimicrobial stewardship interventions in patients with bloodstream infections in a Japanese tertiary hospital

BACKGROUND

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has the potential to permit early organism identification and optimization of antibiotic therapy. However, MALDI-TOF MS combined with antimicrobial stewardship is available at only a limited number of institutions. Here, we evaluated the clinical impact of implementing MALDI-TOF MS combined with antimicrobial stewardship intervention in patients with bloodstream infections.

METHODS

We conducted a single-centre, prospective cohort study to evaluate the clinical impact of implementing MALDI-TOF MS combined with antimicrobial stewardship intervention in patients with bloodstream infections. Processes and clinical outcomes in patients with bloodstream infections were compared before and after implementation of MALDI-TOF MS.

RESULTS

Compared with the conventional identification method, MALDI-TOF MS combined with antimicrobial stewardship intervention significantly decreased the time to organism identification (48.6 ± 46.0 hours vs 78.1 ± 38.9 hours, P < 0.001), effective antimicrobial therapy (12.9 ± 19.0 hours vs 26.2 ± 44.8 hours, P < 0.001) and optimal antimicrobial therapy (53.3 ± 55.0 hours vs 91.7 ± 88.7 hours, P < 0.001. Moreover, the rate of clinical failure (14.0% vs 33.3%, P < 0.001) and incidence of adverse events (7.5% vs 23.9%, P < 0.001) was lower in the MALDI-TOF MS group than in the conventional identification group. A multivariate Cox proportional hazard analysis indicated that implementation of MALDI-TOF MS was a protective factor against clinical failure in patients with bloodstream infections (hazard ratio, 0.61; 95% confidence interval, 0.38-0.99; P = 0.047).

CONCLUSIONS

Implementation of the MALDI-TOF MS combined with antimicrobial stewardship intervention facilitated early optimization of antimicrobial therapy with a remarkable concomitant reduction in clinical failure and adverse events in patients with bloodstream infections.

Ideal and Actual Impact of Rapid Diagnostic Testing and Antibiotic Stewardship on Antibiotic Prescribing and Clinical Outcomes in Children With Positive Blood Cultures

BACKGROUND

Implementing matrix-assisted laser desorption ionization-time of flight and multiplex polymerase chain reaction has been associated with decreased mortality and hospital length of stay in adults, but the impact in pediatrics is less understood.

METHODS

This pre-post quasi-experimental study compared antibiotic prescribing for positive blood cultures in patients ≤21 years of age collected in 2012 (preintervention) and in 2015 (after matrix-assisted laser desorption ionization-time of flight/multiplex polymerase chain reaction). Time to effective and optimal antimicrobial therapy was evaluated using Cox proportional hazards regression. Time to ideal optimal therapy was estimated as the earliest potential initiation of optimal therapy. Antibiotic use and clinical outcomes were measured.

RESULTS

There were 242 and 192 positive monomicrobial blood cultures in 2012 and 2015, respectively. Postintervention, time to optimal therapy (73.8 vs. 48.8 hours; P < 0.001) and organism identification (55.6 vs. 29.5 hours; P < 0.001) were reduced, and patients were more likely to receive optimal therapy by 7 days (hazard ratio, 1.85; P < 0.001). In the ideal scenario in 2015, there was an 8.8-hour delay in initiating optimal therapy based on the time that sufficient microbiologic data were available. Postintervention, time to effective therapy (2.8 vs. 2.7 hours; P = 0.782) and clinical outcomes did not differ. Unnecessary antibiotic duration for probable contaminants (skin flora) (43.1 vs. 29.7 hours; P = 0.027), vancomycin for methicillin-sensitive Staphylococcus aureus (54.0 vs. 41.3 hours; P = 0.008) and nonpenicillin/ampicillin antibiotics for group A Streptococcus, group B Streptococcus and Enterococcus faecalis (87.2 vs. 33.4 hours; P < 0.001) were reduced postintervention.

CONCLUSIONS

Rapid diagnostics reduced time to optimal antimicrobial therapy and unnecessary antibiotic use without worse clinical outcomes.

Estimated Clinical and Economic Impact through Use of a Novel Blood Collection Device To Reduce Blood Culture Contamination in the Emergency Department: a Cost-Benefit Analysis

Blood culture contamination results in increased hospital costs and exposure to antimicrobials. We evaluated the potential clinical and economic benefits of an initial specimen diversion device (ISDD) when routinely utilized for blood culture collection in the emergency department (ED) of a quaternary care medical center. A decision analysis model was created to identify the cost benefit of the use of the ISDD device in the ED. Probabilistic costs were determined from the published literature and the direct observation of pharmacy/microbiology staff. The primary outcome was the expected per-patient cost savings (microbiology, pharmacy, and indirect hospital costs) with the routine use of an ISDD from a hospital perspective. The indirect costs included those related to an increased hospital length of stay, additional procedures, adverse drug reactions, and hospital-acquired infections. Models were created to represent hospitals that routinely or do not routinely use rapid diagnostic tests (RDT) on positive blood cultures. The routine implementation of ISDD for blood culture collection in the ED was cost beneficial compared to conventional blood culture collection methods. When implemented in a hospital utilizing RDT with a baseline contamination rate of 6%, ISDD use was associated with a cost savings of $272 (3%) per blood culture in terms of overall hospital costs and $28 (5.4%) in direct-only costs. The main drivers of cost were baseline contamination rates and the duration of antibiotics given to patients with negative blood cultures. These findings support the routine use of ISDD during blood culture collection in the ED as a cost-beneficial strategy to reduce the clinical and economic impact of blood culture contamination in terms of microbiology, pharmacy, and wider indirect hospital impacts.

Rapid Diagnostics for Blood Cultures: Supporting Decisions for Antimicrobial Therapy and Value-Based Care

Bacteremia and sepsis are critically important syndromes with high mortality, morbidity, and associated costs. Bloodstream infections and sepsis are among the top causes of mortality in the US, with >600 deaths each day. Most septic patients can be found in emergency medicine departments or critical care units, settings in which rapid administration of targeted antibiotic therapy can reduce mortality. Unfortunately, routine blood cultures are not rapid enough to aid in the decision of therapeutic intervention at the onset of bacteremia. As a result, empiric, broad-spectrum treatment is common-a costly approach that may fail to target the correct microbe effectively, may inadvertently harm patients via antimicrobial toxicity, and may contribute to the evolution of drug-resistant microbes. To overcome these challenges, laboratorians must understand the complexity of diagnosing and treating septic patients, focus on creating algorithms that rapidly support decisions for targeted antibiotic therapy, and synergize with existing emergency department and critical care clinical practices put forth in the Surviving Sepsis Guidelines.

Interplay between Rapid Diagnostic Tests and Antimicrobial Stewardship Programs among Patients with Bloodstream and Other Severe Infections

BACKGROUND

Antimicrobial stewardship programs (ASPs) aim to provide optimal antimicrobial therapy to patients quickly to improve the likelihood of overcoming infection while reducing the risk of adverse effects. Rapid diagnostic tests (RDTs) for infectious diseases have become an integral tool for ASPs to achieve these aims.

CONTENT

This review explored the demonstrated clinical value of longer-standing technologies and implications of newer RDTs from an antimicrobial stewardship perspective. Based on available literature, the focus was on the use of RDTs in bloodstream infections (BSIs), particularly those that perform organism identification and genotypic resistance detection, phenotypic susceptibility testing, and direct specimen testing. Clinical implications of rapid testing among respiratory, central nervous system, and gastrointestinal infections are also reviewed.

SUMMARY

Coupling RDTs with ASPs facilitates the appropriate and timely use of test results, translating into improved patient outcomes through optimization of antimicrobial use. These benefits are best demonstrated in the use of RDT in BSIs. Rapid phenotypic susceptibility testing offers the potential for early pharmacokinetic/pharmacodynamic optimization, and direct specimen testing on blood may allow ASPs to initiate appropriate therapy and/or tailor empiric therapy even sooner than other RDTs. RDTs for respiratory, central nervous system, and gastrointestinal illnesses have also shown significant promise, although more outcome studies are needed to evaluate their full impact.

Importance evaluation of spectral lines in Laser-induced breakdown spectroscopy for classification of pathogenic bacteria

The correct classification of pathogenic bacteria is significant for clinical diagnosis and treatment. Compared with the use of whole spectral data, using feature lines as the inputs of the classification model can improve the correct classification rate (CCR) and reduce the analyzing time. In order to select feature lines, we need to investigate the contribution to the CCR of each spectral line. In this paper, two algorithms, important weights based on principal component analysis (IW-PCA) and random forests (RF), were proposed to evaluate the importance of spectra lines. The laser-induced plasma spectra (LIBS) of six common clinical pathogenic bacteria species were measured and a support vector machine (SVM) classifier was used to classify the LIBS of bacteria species. In the proposed IW-PCA algorithm, the product of the loading of each line and the variance of the corresponding principal component were calculated. The maximum product of each line calculated from the first three PCs was used to represent the line's importance weight. In the RF algorithm, the Gini index reduction value of each line was considered as the line's importance weight. The experimental results demonstrated that the lines with high importance were more suitable for classification and can be chosen as feature lines. The optimal number of feature lines used in the SVM classifier can be determined by comparing the CCRs with a different number of feature lines. Importance weights evaluated by RF are more suitable for extracting feature lines using LIBS combined with an SVM classification mechanism than those evaluated by IW-PCA. Furthermore, the two methods mutually verified the importance of selected lines and the lines evaluated important by both IW-PCA and RF contributed more to the CCR.

The Use of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) for the Identification of Pathogens Causing Sepsis

BACKGROUND

Sepsis is a life-threatening condition with high rates of morbidity and mortality; effective and appropriate antibiotic therapy is essential for ensuring patient improvement. To aid in the diagnosis of sepsis, blood cultures are drawn and sent to the microbiology laboratory for pathogen growth, identification, and susceptibility testing. The clinical microbiology laboratory can assist the medical team by providing timely identification of the pathogen(s) causing the bloodstream infection through the use of rapid diagnostic technology. One of these rapid diagnostic technologies, MALDI-TOF MS, has been proven to reduce the time required for appropriate antibiotic therapy when used to identify pathogens grown in culture. This technology has also been used to identify pathogens directly from the positive blood cultures with great success.

CONTENT

In this minireview, we summarize the different methods that have been developed to directly identify pathogens from positive blood cultures by use of MALDI-TOF MS and the effect of this technology on patient outcomes. Additionally, we touch on current research in the field, including the identification of antimicrobial resistance directly from positive blood cultures by MALDI-TOF MS.

SUMMARY

Rapid identification of pathogens is important in the survival of patients undergoing a septic event. MALDI-TOF MS technology has played an important role in rapid identification, which has led to a reduction in the time to appropriate antibiotic therapy and contributed to the improvement of patient outcomes. The high sensitivity and specificity of MALDI-TOF MS identification, in combination with MALDI-TOF's rapid function and reduced labor costs, make this technology an attractive choice for clinical laboratories.

Role of the Clinical Microbiology Laboratory in Antimicrobial Stewardship

For adequate antimicrobial stewardship, microbiology needs to move from the laboratory to become physically and verbally amenable to the caregivers of an institution. Herein, we describe the contributions of our microbiology department to the antimicrobial stewardship program of a large teaching hospital as 10 main points ranging from the selection of patients deemed likely to benefit from a fast track approach, to their clinical samples, or the rapid reporting of results via a microbiology hotline, to rapid searches for pathogens and susceptibility testing. These points should serve as guidelines for similar programs designed to decrease the unnecessary use of antimicrobials.

Collaboration between an antimicrobial stewardship team and the microbiology laboratory can shorten time to directed antibiotic therapy for methicillin-susceptible staphylococcal bacteremia and to discontinuation of antibiotics for coagulase-negative staphylococcal contaminants

BACKGROUND

Rapid identification of Gram-positive cocci in clusters (GPCC) in positive blood cultures (pBC) may limit exposure to unnecessary or inappropriate antibiotics.

METHODS

Inpatients with pBC showing GPCC between October 2013 and December 2017 were included. In the baseline period (BL), final ID and susceptibility results were reported in the electronic medical record (EMR) within 48 h of telephoned Gram stain report. The laboratory introduced rapid phenotypic identification and direct susceptibility testing (INT1), later replaced by PCR (INT2). In the last Intervention (INT3), Antimicrobial Stewardship Response Team (ASRT) contacted providers with PCR results and recommendations.

RESULTS

Time to directed therapy (TDT) for MSSA and coagulase-negative Staphylococci (CoNS) decreased from BL to INT3 (48.5-17.9 h, 50.3-16.4 h, respectively). Time to ID from BL to INT3 for MSSA and CoNS also decreased (23.2-1.9 h, 44.7-2.8, respectively).

CONCLUSIONS

TDT can be improved by modification of reporting methods with utilization of an ASRT.

Implementation and optimization of molecular rapid diagnostic tests for bloodstream infections

PURPOSE

The implementation and optimization of molecular rapid diagnostic tests (mRDTs) as an antimicrobial stewardship intervention for patients with bloodstream infections (BSIs) are reviewed.

SUMMARY

All U.S. acute care hospitals accredited by the Joint Commission are required to implement an antimicrobial stewardship program (ASP). Of the many interventions available to ASPs, mRDTs have demonstrated consistent, meaningful results on antimicrobial optimization and patient outcomes. Even among infectious diseases and antimicrobial stewardship-trained pharmacists, significant knowledge and familiarity gaps exist regarding available mRDTs and how best to implement and optimize them. Given the paucity of infectious diseases and/or antimicrobial stewardship-trained pharmacists, the mandates for establishing ASPs will require non-infectious diseases/antimicrobial stewardship-trained pharmacists to implement stewardship interventions, which may include mRDTs, within their institution. Optimization of mRDTs requires adequate diagnostic stewardship, specifically evaluating how mRDT implementation may decrease costs and assist in meeting antimicrobial stewardship regulatory requirements. Knowledge of how these technologies will augment existing microbiology and antimicrobial stewardship workflow is essential. Finally, selecting the right mRDT necessitates familiarity with the instrument's capabilities and with the institutional antibiogram.

CONCLUSION

mRDTs have demonstrated the ability to be one of the most powerful antimicrobial stewardship interventions. Pharmacists required to implement an ASP in their institution should consider mRDTs as standard of care for patients with BSIs.

Disease-based antimicrobial stewardship: a review of active and passive approaches to patient management

Although new antimicrobial stewardship programmes (ASPs) often begin by targeting the reduction of antimicrobial use, an increasing focus of ASPs is to improve the management of specific infectious diseases. Disease-based antimicrobial stewardship emphasizes improving patient outcomes by optimizing antimicrobial use and increasing compliance with performance measures. Directing efforts towards the comprehensive management of specific infections allows ASPs to promote the shift in healthcare towards improving quality, safety and patient outcome metrics for specific diseases. This review evaluates published active and passive disease-based antimicrobial stewardship interventions and their impact on antimicrobial use and associated patient outcomes for patients with pneumonia, acute bacterial skin and skin structure infections, bloodstream infections, urinary tract infections, asymptomatic bacteriuria, Clostridium difficile infection and intra-abdominal infections. Current literature suggests that disease-based antimicrobial stewardship effects on medical management and patient outcomes vary based on infectious disease syndrome, resource availability and intervention type.

New paradigm for rapid achievement of appropriate therapy in special populations: coupling antibiotic dose optimization rapid microbiological methods

INTRODUCTION

Some special patient populations (e.g. critically ill, burns, hematological malignancy, post-major surgery, post-major trauma) have characteristics that lead to higher rates of failure and mortality associated with infection. Choice of effective antibiotics and optimized doses are challenging in these patients that are commonly infected by multidrug-resistant pathogens. Areas covered: A review of the importance of diagnosis and the place of newer microbiological methods (e.g. whole-genome sequencing) to ensure rapid transition from empiric to directed antibiotic therapy is provided. The effects of pathophysiological changes on antibiotic pharmacokinetics are also provided. Expert opinion: Product information dosing regimens do not address the pharmacokinetic alterations that can occur in special patient populations and increase the likelihood of therapeutic failure and the emergence of bacterial resistance. Altered dosing approaches, supplemented with the use of dosing software and therapeutic drug monitoring, may be needed to ensure optimal antibiotic exposure and better therapeutic outcomes in these patients with severe infection. Dose optimization needs to be coupled with advanced microbiological techniques that enable rapid microbiological identification and characterization of resistance mechanism to ensure that maximally effective directed therapy can be chosen.

The Cost-Effectiveness of Rapid Diagnostic Testing for the Diagnosis of Bloodstream Infections with or without Antimicrobial Stewardship

Bloodstream infections are associated with considerable morbidity and health care costs. Molecular rapid diagnostic tests (mRDTs) are a promising complement to conventional laboratory methods for the diagnosis of bloodstream infections and may reduce the time to effective therapy among patients with bloodstream infections. The concurrent implementation of antimicrobial stewardship programs (ASPs) may reinforce these benefits. The aim of this study was to evaluate the cost-effectivenesses of competing strategies for the diagnosis of bloodstream infection alone or combined with an ASP. To this effect, we constructed a decision-analytic model comparing 12 strategies for the diagnosis of bloodstream infection. The main arms compared the use of mRDT and conventional laboratory methods with or without an ASP. The baseline strategy used as the standard was the use of conventional laboratory methods without an ASP, and our decision-analytic model assessed the cost-effectivenesses of 5 principal strategies: mRDT (with and without an ASP), mRDT with an ASP, mRDT without an ASP, conventional laboratory methods with an ASP, and conventional laboratory methods without an ASP. Furthermore, based on the availability of data in the literature, we assessed the cost-effectivenesses of 7 mRDT subcategories, as follows: PCR with an ASP, matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analysis with an ASP, peptide nucleic acid fluorescent in situ hybridization (PNA-FISH) with an ASP, a blood culture nanotechnology microarray system for Gram-negative bacteria (BC-GP) with an ASP, a blood culture nanotechnology microarray system for Gram-positive bacteria (BC-GN) with an ASP, PCR without an ASP, and PNA-FISH without an ASP. Our patient population consisted of adult inpatients in U.S. hospitals with suspected bloodstream infection. The time horizon of the model was the projected life expectancy of the patients. In a base-case analysis, cost-effectiveness was determined by calculating the numbers of bloodstream infection deaths averted, the numbers of quality-adjusted life years gained, and incremental cost-effectiveness ratios (ICERs). In a probabilistic analysis, uncertainty was addressed by plotting cost-effectiveness planes and acceptability curves for various willingness-to-pay thresholds. In the base-case analysis, MALDI-TOF analysis with an ASP was the most cost-effective strategy, resulting in savings of $29,205 per quality-adjusted life year and preventing 1 death per 14 patients with suspected bloodstream infection tested compared to conventional laboratory methods without an ASP (ICER, -$29,205/quality-adjusted life year). BC-GN with an ASP (ICER, -$23,587/quality-adjusted life year), PCR with an ASP (ICER, -$19,833/quality-adjusted life year), and PCR without an ASP (ICER, -$21,039/quality-adjusted life year) were other cost-effective options. In the probabilistic analysis, mRDT was dominant and cost-effective in 85.1% of simulations. Importantly, mRDT with an ASP had an 80.0% chance of being cost-effective, while mRDT without an ASP had only a 41.1% chance. In conclusion, our findings suggest that mRDTs are cost-effective for the diagnosis of patients with suspected bloodstream infection and can reduce health care expenditures. Notably, the combination of mRDT and an ASP can result in substantial health care savings.

Recent Advances and Ongoing Challenges in the Diagnosis of Microbial Infections by MALDI-TOF Mass Spectrometry

Timeliness and accuracy in the diagnosis of microbial infections are associated with decreased mortality and reduced length of hospitalization, especially for severe, life-threatening infections. A rapid diagnosis also allows for early streamlining of empirical antimicrobial therapies, thus contributing to limit the emergence and spread of antimicrobial resistance. The introduction of matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) for routine identification of microbial pathogens has profoundly influenced microbiological diagnostics, and is progressively replacing biochemical identification methods. Compared to currently used identification methods, MALDI-TOF MS has the advantage of identifying bacteria and yeasts directly from colonies grown on culture plates for primary isolation in a few minutes and with considerable material and labor savings. The reliability and accuracy of MALDI-TOF MS in identification of clinically relevant bacteria and yeasts has been demonstrated by several studies showing that the performance of MALDI-TOF MS is comparable or superior to phenotypic methods currently in use in clinical microbiology laboratories, and can be further improved by database updates and analysis software upgrades. Besides microbial identification from isolated colonies, new perspectives are being explored for MALDI-TOF MS, such as identification of pathogens directly from positive blood cultures, sub-species typing, and detection of drug resistance determinants. In this review, we summarize the state of the art in routine identification of microbial pathogens by MALDI-TOF MS, and highlight recent advancements of this technology in special applications, such as strain typing, assessment of drug susceptibility, and detection of virulence factors.

Impact of QuickFISH in addition to antimicrobial stewardship on vancomycin use and resource utilization in cancer patients with coagulase-negative staphylococcal blood cultures

OBJECTIVE

To evaluate the impact of rapidly identifying coagulase-negative staphylococci (CoNS) from positive blood cultures combined with an established antimicrobial stewardship (AS) programme at a tertiary cancer centre.

METHODS

We compared cancer patients ≥18 years old who between 01/1/13 and 12/31/13 had one or more positive CoNS blood culture(s) identified by Staphylococcus QuickFISH® (a peptide nucleic acid fluorescence in situ hybridization assay) with cancer patients ≥18 years old who had CoNS identified by standard microbiological techniques between 01/01/11 and 12/31/11 (baseline). Positive blood culture results were reported to the clinician by microbiology staff; restricted antibiotics (e.g., vancomycin) required approval by the AS team.

RESULTS

There were 196 baseline and 103 QuickFISH patients. Faster median time to organism identification (33 (IQR 27-46) versus 49 (IQR 39-63) hours, p < 0.001), more vancomycin avoidance (51/103 (50%) versus 60/196 (31%), p 0.002), shorter median antibiotic duration (1 (IQR 0-3) versus 2 (IQR 0-6) days, p 0.019), fewer central venous catheter (CVC) removals (14/78 (18%) versus 57/160 (36%), p 0.004), and reduced vancomycin level monitoring (16/52 (31%) versus 71/136 (52%), p 0.009) were observed in the QuickFISH group. QuickFISH implementation was predictive of a lower likelihood of antibiotic therapy prescription (OR 0.35, 95%CI 0.20-0.62, p < 0.001). Prior transplant (RR 1.47, 95%CI 1.13-1.92, p 0.004), neutropenia (RR 1.47, 95%CI 1.09-1.99, p 0.012), multiple positive blood cultures (RR 4.23, 95%CI 3.23-5.54, p < 0.001), and CVC (RR 1.60, 95%CI 1.02-2.53, p 0.043) were independent factors for antibiotic duration.

CONCLUSIONS

QuickFISH implementation plus AS support leads to greater avoidance of vancomycin therapy and improved resource utilization in cancer patients with CoNS blood cultures.

Sepsis: the LightCycler SeptiFast Test MGRADE®, SepsiTest™ and IRIDICA BAC BSI assay for rapidly identifying bloodstream bacteria and fungi - a systematic review and economic evaluation

BACKGROUND

Sepsis can lead to multiple organ failure and death. Timely and appropriate treatment can reduce in-hospital mortality and morbidity.

OBJECTIVES

To determine the clinical effectiveness and cost-effectiveness of three tests [LightCycler SeptiFast Test MGRADE(®) (Roche Diagnostics, Risch-Rotkreuz, Switzerland); SepsiTest(TM) (Molzym Molecular Diagnostics, Bremen, Germany); and the IRIDICA BAC BSI assay (Abbott Diagnostics, Lake Forest, IL, USA)] for the rapid identification of bloodstream bacteria and fungi in patients with suspected sepsis compared with standard practice (blood culture with or without matrix-absorbed laser desorption/ionisation time-of-flight mass spectrometry).

DATA SOURCES

Thirteen electronic databases (including MEDLINE, EMBASE and The Cochrane Library) were searched from January 2006 to May 2015 and supplemented by hand-searching relevant articles.

REVIEW METHODS

A systematic review and meta-analysis of effectiveness studies were conducted. A review of published economic analyses was undertaken and a de novo health economic model was constructed. A decision tree was used to estimate the costs and quality-adjusted life-years (QALYs) associated with each test; all other parameters were estimated from published sources. The model was populated with evidence from the systematic review or individual studies, if this was considered more appropriate (base case 1). In a secondary analysis, estimates (based on experience and opinion) from seven clinicians regarding the benefits of earlier test results were sought (base case 2). A NHS and Personal Social Services perspective was taken, and costs and benefits were discounted at 3.5% per annum. Scenario analyses were used to assess uncertainty.

RESULTS

For the review of diagnostic test accuracy, 62 studies of varying methodological quality were included. A meta-analysis of 54 studies comparing SeptiFast with blood culture found that SeptiFast had an estimated summary specificity of 0.86 [95% credible interval (CrI) 0.84 to 0.89] and sensitivity of 0.65 (95% CrI 0.60 to 0.71). Four studies comparing SepsiTest with blood culture found that SepsiTest had an estimated summary specificity of 0.86 (95% CrI 0.78 to 0.92) and sensitivity of 0.48 (95% CrI 0.21 to 0.74), and four studies comparing IRIDICA with blood culture found that IRIDICA had an estimated summary specificity of 0.84 (95% CrI 0.71 to 0.92) and sensitivity of 0.81 (95% CrI 0.69 to 0.90). Owing to the deficiencies in study quality for all interventions, diagnostic accuracy data should be treated with caution. No randomised clinical trial evidence was identified that indicated that any of the tests significantly improved key patient outcomes, such as mortality or duration in an intensive care unit or hospital. Base case 1 estimated that none of the three tests provided a benefit to patients compared with standard practice and thus all tests were dominated. In contrast, in base case 2 it was estimated that all cost per QALY-gained values were below £20,000; the IRIDICA BAC BSI assay had the highest estimated incremental net benefit, but results from base case 2 should be treated with caution as these are not evidence based.

LIMITATIONS

Robust data to accurately assess the clinical effectiveness and cost-effectiveness of the interventions are currently unavailable.

CONCLUSIONS

The clinical effectiveness and cost-effectiveness of the interventions cannot be reliably determined with the current evidence base. Appropriate studies, which allow information from the tests to be implemented in clinical practice, are required.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015016724.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Experience With Rapid Microarray-Based Diagnostic Technology and Antimicrobial Stewardship for Patients With Gram-Positive Bacteremia

OBJECTIVE To describe the impact of rapid diagnostic microarray technology and antimicrobial stewardship for patients with Gram-positive blood cultures. DESIGN Retrospective pre-intervention/post-intervention study. SETTING A 1,200-bed academic medical center. PATIENTS Inpatients with blood cultures positive for Staphylococcus aureus, Enterococcus faecalis, E. faecium, Streptococcus pneumoniae, S. pyogenes, S. agalactiae, S. anginosus, Streptococcus spp., and Listeria monocytogenes during the 6 months before and after implementation of Verigene Gram-positive blood culture microarray (BC-GP) with an antimicrobial stewardship intervention. METHODS Before the intervention, no rapid diagnostic technology was used or antimicrobial stewardship intervention was undertaken, except for the use of peptide nucleic acid fluorescent in situ hybridization and MRSA agar to identify staphylococcal isolates. After the intervention, all Gram-positive blood cultures underwent BC-GP microarray and the antimicrobial stewardship intervention consisting of real-time notification and pharmacist review. RESULTS In total, 513 patients with bacteremia were included in this study: 280 patients with S. aureus, 150 patients with enterococci, 82 patients with stretococci, and 1 patient with L. monocytogenes. The number of antimicrobial switches was similar in the pre-BC-GP (52%; 155 of 300) and post-BC-GP (50%; 107 of 213) periods. The time to antimicrobial switch was significantly shorter in the post-BC-GP group than in the pre-BC-GP group: 48±41 hours versus 75±46 hours, respectively (P<.001). The most common antimicrobial switch was de-escalation and time to de-escalation, was significantly shorter in the post-BC-GP group than in the pre-BC-GP group: 53±41 hours versus 82±48 hours, respectively (P<.001). There was no difference in mortality or hospital length of stay as a result of the intervention. CONCLUSIONS The combination of a rapid microarray diagnostic test with an antimicrobial stewardship intervention improved time to antimicrobial switch, especially time to de-escalation to optimal therapy, in patients with Gram-positive blood cultures. Infect Control Hosp Epidemiol 2016;1-6.

Culturing rate and the surveillance of bloodstream infections: a population-based assessment

OBJECTIVES

Diagnosis of a bloodstream infection (BSI) requires a positive blood culture. However, low culturing rates will underestimate the true incidence of BSI and high rates may increase the risk of false-positive results. We sought to investigate the relationship between culturing rates and the incidence of BSI at the population level.

METHODS

Population-based surveillance was conducted in the western interior of British Columbia, Canada, between 1 April 2010 and 31 March 2017.

RESULTS

Among 60 243 blood culture sets drawn, 5591 isolates were obtained, of which 2303 were incident, 1929 were repeat positive and 1359 were contaminants. Overall annual rates of culturing, incident, repeat positive and contaminant isolates were 4832, 185, 155 and 109 per 100 000 population, respectively. During the 84-month study, there was an increase in the culturing rate that reached a plateau at 48 months (5403 cultures per 100 000 per year). The rate of both repeat isolates and contaminants increased linearly with an increasing culturing rate. However, the incident isolate rate reached an inflection point at a rate of approximately 5550 per 100 000 annually, at which point the increase in incident isolates per culture sample was diminished. At a culturing rate above 6123 per 100 000 per year, the number of repeat isolates exceeded that of incident isolates.

CONCLUSIONS

The determined incidence of BSI will increase with increased culturing in a population. Further studies are needed to explore optimal BSI culturing rates in other populations.

Recent advances in the microbiological diagnosis of bloodstream infections

Rapid identification (ID) and antimicrobial susceptibility testing (AST) of the causative agent(s) of bloodstream infections (BSIs) are essential for the prompt administration of an effective antimicrobial therapy, which can result in clinical and financial benefits. Immediately after blood sampling, empirical antimicrobial therapy, chosen on clinical and epidemiological data, is administered. When ID and AST results are available, the clinician decides whether to continue or streamline the antimicrobial therapy, based on the results of the in vitro antimicrobial susceptibility profile of the pathogen. The aim of the present study is to review and discuss the experimental data, advantages, and drawbacks of recently developed technological advances of culture-based and molecular methods for the diagnosis of BSI (including mass spectrometry, magnetic resonance, PCR-based methods, direct inoculation methods, and peptide nucleic acid fluorescence in situ hybridization), the understanding of which could provide new perspectives to improve and fasten the diagnosis and treatment of septic patients. Although blood culture remains the gold standard to diagnose BSIs, newly developed methods can significantly shorten the turnaround time of reliable microbial ID and AST, thus substantially improving the diagnostic yield.

A 72-h intervention for improvement of the rate of optimal antibiotic therapy in patients with bloodstream infections

Antimicrobial stewardship programs are implemented to optimize the use of antibiotics and control the spread of antibiotic resistance. Many antimicrobial stewardship interventions have demonstrated significant efficacy in reducing unnecessary prescriptions of antibiotics, the duration of antimicrobial therapy, and mortality. We evaluated the benefits of a combination of rapid diagnostic tests and an active re-evaluation of antibiotic therapy 72 h after the onset of bloodstream infection (BSI). All patients with BSI from November 2015 to November 2016 in a 1100-bed university hospital in Rome, where an Infectious Disease Consultancy Unit (Unità di Consulenza Infettivologica, UDCI) is available, were re-evaluated at the bedside 72 h after starting antimicrobial therapy and compared to two pre-intervention periods: the UDCI was called by the ward physician for patients with BSI and the UDCI was called directly by the microbiologist immediately after a pathogen was isolated from blood cultures. Recommendations for antibiotic de-escalation or discontinuation significantly increased (54%) from the two pre-intervention periods (32% and 27.2%, p < 0.0001). Appropriate escalation also significantly increased (22.5%) from the pre-intervention periods (8.1% and 8.2%, p < 0.0001). The total duration of antibiotic therapy decreased with intervention (from 21.9 days [standard deviation, SD 15.4] in period 1 to 19.3 days [SD 13.3] in period 2 to 17.7 days in period 3 [SD 11.5]; p = 0.002) and the length of stay was significantly shorter (from 29.7 days [SD 29.3] in period 1 to 26.8 days [SD 24.7] in period 2 to 24.2 days in period 3 [SD 20.7]; p = 0.04) than in the two pre-intervention periods. Mortality was similar among the study periods (31 patients died in period 1 (15.7%), 39 (16.7%) in period 2, and 48 (15.3%) in period 3; p = 0.90). Rapid diagnostic tests and 72 h re-evaluation of empirical therapy for BSI significantly correlated with an improved rate of optimal antibiotic therapy and decreased duration of antibiotic therapy and length of stay.

Analysis of an Infectious Diseases Pharmacist on Call Pager Program to Inform Educational Efforts

Background: An on call infectious diseases (ID) pharmacist may be used as a resource for physicians, pharmacists, and other health care providers to help answer questions regarding anti-infective agents. Objective: To assess type, requestor, resources dedicated, and temporal trends of questions received through an ID pharmacist on call pager program. A secondary objective was to gather insight as to how this information was utilized to inform educational initiatives. Methods: This was a retrospective study of questions received by the ID pharmacist on call via pager at a large academic medical center. Question data were documented in a central database and analyzed to assess temporal trends and question type, and qualitatively analyzed to determine areas for targeted educational efforts. Results: The ID pharmacist on call recorded 545 questions during the 1-year study period; questions were composed of various antimicrobial agent-related queries, including antibiotic spectrum and selection (n = 251, 46.1%), dosing of antimicrobials (n = 195, 35.8%), and drug monitoring (n = 26, 4.8%). Targeted educational initiatives secondary to questions received included pharmacist education regarding the use of polymyxin antibiotics and antibiotic dosing protocol updates. Conclusions: An ID pharmacist on call pager program was utilized to inquire about antibiotic spectrum and selection for the majority of questions. Records of questions received may be utilized to direct educational efforts and create or revise targeted resources for pharmacists and other clinicians.

Impact of Matrix-Assisted Laser Desorption and Ionization Time-of-Flight and Antimicrobial Stewardship Intervention on Treatment of Bloodstream Infections in Hospitalized Children

BACKGROUND.

Early definitive identification of infectious pathogens coupled with antimicrobial stewardship interventions allow for targeted and timely administration of antimicrobials. We investigated the combined impact of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) technology and an antimicrobial stewardship program (ASP) in pediatric patients with blood stream infections (BSIs).

METHODS.

This is a single-center study comparing a control group of patients from October 2009 to July 2010 with BSIs to a cohort of patients postimplementation of MALDI-TOF and an ASP, from October 2013 to July 2014. Primary outcome was time to optimal therapy. Secondary outcomes included time to effective therapy, 30-day all-cause mortality, 30-day readmission rate, hospital length of stay, and intensive care admission.

RESULTS.

One hundred episodes of BSIs were identified in the preintervention period, and 121 episodes were identified in the postintervention period. Time from blood culture collection to organism identification was significantly reduced in the prospective cohort compared with historical controls (18.8 vs 43.7 hours, respectively). A total of 73 ASP interventions were made on the treatment of BSIs in the postintervention period. Combined use of MALDI-TOF and ASP significantly reduced time to optimal therapy (77.0 to 54.2 hours, P < .001). In the subgroup analysis of Gram-negative bacteremia, time to effective and optimal therapy were significantly reduced (2.0 vs 0.7 hours and 146.8 vs 48.0 hours, respectively). There were no significant differences in clinical outcomes.

CONCLUSIONS.

The combined use of MALDI-TOF and ASP allows early optimization of antimicrobial therapy in pediatric inpatients with BSIs.

Improving American Healthcare Through "Clinical Lab 2.0": A Project Santa Fe Report

Project Santa Fe was established both to provide thought leadership and to help develop the evidence base for the valuation of clinical laboratory services in the next era of American healthcare. The participants in Project Santa Fe represent major regional health systems that can operationalize laboratory-driven innovations and test their valuation in diverse regional marketplaces in the United States. We provide recommendations from the inaugural March 2016 meeting of Project Santa Fe. Specifically, in the transition from volume-based to value-based health care, clinical laboratories are called upon to provide programmatic leadership in reducing total cost of care through optimization of time-to-diagnosis and time-to-effective therapeutics, optimization of care coordination, and programmatic support of wellness care, screening, and monitoring. This call to action is more than working with industry stakeholders on the basis of our expertise; it is providing leadership in creating the programs that accomplish these objectives. In so doing, clinical laboratories can be effectors in identifying patients at risk for escalation in care, closing gaps in care, and optimizing outcomes of health care innovation. We also hope that, through such activities, the evidence base will be created for the new value propositions of integrated laboratory networks. In the very simplest sense, this effort to create “Clinical Lab 2.0” will establish the impact of laboratory diagnostics on the full 100% spend in American healthcare, not just the 2.5% spend attributed to in vitro diagnostics. In so doing, our aim is to empower regional and local laboratories to thrive under new models of payment in the next era of American health care delivery.