Advancing Diagnostic Stewardship for Healthcare Associated Infections, Antibiotic Resistance, and Sepsis

Implementation of multifaceted diagnostic stewardship for Clostridioides difficile infection during the COVID-19 pandemic at a small Japanese hospital

Objective

Clostridioides difficile infection (CDI) is a common, healthcare-associated infection. However, in Japan, testing for CDI is infrequent, suggesting that its incidence may be underestimated. This study aimed to examine the implementation of a multifaceted, diagnostic stewardship (DS) for CDI in a small Japanese hospital during the coronavirus 2019 pandemic.

Design

Before-after study.

Setting

A small Japanese community hospital.

Participants

Healthcare workers including physicians, nurses, and pharmacists.

Interventions

A multifaceted intervention including (1) the addition of CD testing criteria to the hospital guidelines; (2) provision of a tutorial on CD testing to physicians, nurses, and pharmacists; (3) assessment by clinical pharmacists and nurses of the need for CD testing in patients with nosocomial diarrhea and issuance of recommendations for CD testing to physicians; (4) reporting of data on the CD testing rate and CDI incidence in the study center.

Results

The CD testing rate increased before the pandemic (+0.16/10,000 patient-days (PD); P = .28), decreased significantly during the pandemic (-0.79/10,000 PD; P = .02), and then increased significantly immediately after the implementation of the intervention (+29.6/10,000 PD; P < .01). Similarly, the CDI incidence increased significantly before the pandemic (+0.26/10,000 PD; P = .02) and decreased significantly during the pandemic (-0.49/10,000 PD; P = .01). Implementation of the intervention resulted in an immediate and significant increase in the CDI incidence (+6.2/10,000 PD; P < .01).

Conclusion

Multifaceted DS involving multidisciplinary specialists was effective in improving CD testing, suggesting that appropriate testing can contribute to diagnosing CDI accurately.

Lack of microbiological awareness on the ward as a key factor for inappropriate use of anti-infectives: results of a point prevalence study and user satisfaction survey in a large university hospital in Austria

PURPOSE

Although diagnostic stewardship issues in clinical microbiology harbor an optimization potential for anti-infective consumption, they are only marginally addressed in antimicrobial stewardship (AMS) programs. As part of an AMS point prevalence (PPS) survey we therefore aimed to gain a more dynamic view on the microbiological awareness within therapeutic regimens. By examining whether initial microbiological sampling was performed and in which way microbiological results were incorporated into further treatment considerations we sought to find out to what extent these points determine the appropriateness of treatment regimens.

METHODS

PPS was performed at the University Hospital Salzburg (1524 beds) in May 2021. Relevant data was determined from the patient charts and the appropriateness of anti-infective use was assessed using predefined quality indicators. Six months after the PPS, a questionnaire was administered to clinicians to obtain information on the use of microbiological findings and their relevance in the clinic.

RESULTS

Lack of microbiological awareness in the clinical setting proved to be the key reason for an overall inadequate use of anti-infectives (35.4% of cases rated as inadequate), ahead of the aspects of dose (24.1%), empirical therapy (20.3%) and treatment duration (20.2%). This was particularly the case for broad-acting agents and was most evident in urinary tract infections, skin and soft tissue infections, and pneumonia. The results of the questionnaire indicate a discrepancy between the physicians surveyed and the routine clinical setting.

CONCLUSION

A high potential in improving the use of anti-infectives in hospitals seems to lie in a strong emphasis on microbiological diagnostic stewardship measures.

Diagnostic Stewardship for Urine Cultures

Urinary tract infections are among the most common infectious diagnoses in health care, but most urinary tract infections are diagnosed inappropriately in patients without signs or symptoms of infection. Asymptomatic bacteriuria leads to inappropriate antibiotic prescribing and negative downstream effects, including antimicrobial resistance, health care-associated infections, and adverse drug events. Diagnostic stewardship is the process of modifying the ordering, performing, or reporting of test results to improve clinical care. Diagnostic stewardship impacts the diagnostic pathway to decrease inappropriate detection and treatment of asymptomatic bacteriuria. This article reviews diagnostic stewardship methods and closes with a case study illustrating these principles in practice.

Evaluation of computerized clinical decision support system to reduce unnecessary nasal methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) testing

Our health system implemented a novel clinical decision-support system to reduce unnecessary duplicate nasal methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) orders. In an 8-month period, the rate of duplicate MRSA PCR orders within 7 days declined from 4.7% (370 of 7,861) to 1.2% (120 of 9,833).

A quasi-experimental study of a bundled diagnostic stewardship intervention for ventilator-associated pneumonia

OBJECTIVES

Diagnostic error in the use of respiratory cultures for ventilator-associated pneumonia (VAP) fuels misdiagnosis and antibiotic overuse within intensive care units. In this prospective quasi-experimental study (NCT05176353), we aimed to evaluate the safety, feasibility, and efficacy of a novel VAP-specific bundled diagnostic stewardship intervention (VAP-DSI) to mitigate VAP over-diagnosis/overtreatment.

METHODS

We developed and implemented a VAP-DSI using an interruptive clinical decision support tool and modifications to clinical laboratory workflows. Interventions included gatekeeping access to respiratory culture ordering, preferential use of non-bronchoscopic bronchoalveolar lavage for culture collection, and suppression of culture results for samples with minimal alveolar neutrophilia. Rates of adverse safety outcomes, positive respiratory cultures, and antimicrobial utilization were compared between mechanically ventilated patients (MVPs) in the 1-year post-intervention study cohort (2022-2023) and 5-year pre-intervention MVP controls (2017-2022).

RESULTS

VAP-DSI implementation did not associate with increases in adverse safety outcomes but did associate with a 20% rate reduction in positive respiratory cultures per 1000 MVP days (pre-intervention rate 127 [95% CI: 122-131], post-intervention rate 102 [95% CI: 92-112], p < 0.01). Significant reductions in broad-spectrum antibiotic days of therapy per 1000 MVP days were noted after VAP-DSI implementation (pre-intervention rate 1199 [95% CI: 1177-1205], post-intervention rate 1149 [95% CI: 1116-1184], p 0.03).

DISCUSSION

Implementation of a VAP-DSI was safe and associated with significant reductions in rates of positive respiratory cultures and broad-spectrum antimicrobial use. This innovative trial of a VAP-DSI represents a novel avenue for intensive care unit antimicrobial stewardship. Multicentre trials of VAP-DSIs are warranted.

Central Line-Associated Bloodstream Infection Misclassifications-Rethinking the Centers for Disease Control and Prevention's Central Line-Associated Bloodstream Infection Definition and Its Implications

Centers for Medicare and Medicaid Services imparts financial penalties for central line-associated bloodstream infections (CLABSIs) and other healthcare-acquired infections. Data for this purpose is obtained from the Centers for Disease Control and Prevention (CDC)'s National Health Safety Network. We present examples of misclassification of bloodstream infections into CLABSI by the CDC's definition and present the financial implications of such misclassification and potential long-term implications.

Improving diagnostic accuracy of blood culture-positive cases in a cancer center via an antimicrobial stewardship program and infectious disease consultations

The direct impact of antimicrobial stewardship programs (ASP) and infectious disease (ID) consultations on patients' clinical diagnoses remains unknown. We assessed their influence on improving the diagnostic accuracy of blood culture-positive inpatients at a Japanese cancer center. Our single-center, retrospective observational study was conducted from April 1, 2018 to March 31, 2022 to evaluate two phases: pre-intervention (notification of antimicrobials by the infection control team) and post-intervention (ASP implementation and ID consultation service establishment). There were 42,514 inpatients: 22,096 during the pre-intervention and 20,418 during the intervention periods. A total of 939 blood culture-positive episodes (pre-intervention, n = 434; post-intervention, n = 505) were analyzed. During the pre-intervention period, 28.1% of the patients had an unknown diagnosis, which decreased significantly to 1.2% post-intervention. Furthermore, hepatobiliary tract and other infections increased significantly post-intervention, and the mortality rate due to Staphylococcus aureus infection decreased from 28.6% pre-intervention to 10.4% post-intervention. The trend and level of the total number of culture specimens submitted per 1000 patient days for all culture specimens increased significantly post-intervention. Notably, the two-set rate of monthly blood cultures increased significantly. In conclusion, improving the overall diagnostic process with ASP and ID consultations at cancer centers could lead to the optimization of patient care.

Case series on Trichomonas vaginalis infections: impact of proper sample collection and diagnostic stewardship

This paper elucidates the transformative impact of a strategic shift in diagnostic practices in the detection of Trichomonas vaginalis. It explores five cases where the implementation of a specific diagnostic protocol led to effective identification of the infection. In-depth discussions and a comprehensive literature review underline the necessity for precise diagnosis and the paramount importance of diagnostic stewardship in managing sexually transmitted infections.

Ultrafast detection of β-lactamase resistance in Klebsiella pneumoniae from blood culture by nanopore sequencing

Aim: This study aimed to assess the ultra-fast method using MinION™ sequencing for rapid identification of β-lactamase-producing Klebsiella pneumoniae clinical isolates from positive blood cultures. Methods: Spiked-blood positive blood cultures were extracted using the ultra-fast method and automated DNA extraction for MinION sequencing. Raw reads were analyzed for β-lactamase resistance genes. Multilocus sequence typing and β-lactamase variant characterization were performed after assembly. Results: The ultra-fast method identified clinically relevant β-lactamase resistance genes in less than 1 h. Multilocus sequence typing and β-lactamase variant characterization required 3-6 h. Sequencing quality showed no direct correlation with pore number or DNA concentration. Conclusion: Nanopore sequencing, specifically the ultra-fast method, is promising for the rapid diagnosis of bloodstream infections, facilitating timely identification of multidrug-resistant bacteria in clinical samples.

Implementation of a multidisciplinary process to improve diagnostic stewardship of hospital-onset Clostridioides difficile infections

BACKGROUND

Testing inappropriate stool samples for Clostridioides (Clostridium) difficile can lead to the identification of the patient colonized with C difficile and erroneous diagnosis of an active infection. We hypothesized that a multidisciplinary process to improve diagnostic stewardship could reduce our numbers of hospital-onset C difficile infection (HO-CDI).

METHODS

We created an algorithm describing appropriate stool specimens for polymerase chain reaction testing. The algorithm was converted into "ticket to test" checklist cards designed to accompany each specimen. Rejection of a specimen could occur via nursing staff or laboratory staff.

RESULTS

A baseline period of comparison was established from January 1, 2017 to June 30, 2017. Following implementation of all improvement strategies, a retrospective analysis was done, and the total number of HO-CDI cases in a 6-month period dropped from 57 to 32 cases. During the initial 3 months, the percentage of appropriate samples sent to the lab ranged from 41% to 65%. After the interventions were in place, the percentages improved between 71% and 91%.

CONCLUSIONS

A multidisciplinary approach led to improved diagnostic stewardship to identify true CDI cases. This, in turn, reduced the number of reported HO-CDIs, and resulted in potentially more than $1,080,000 in patient care savings.

Validation of an ICD-Based Algorithm to Identify Sepsis: A Retrospective Study

Background

Sepsis surveillance was important for resources allocation, prevention, and development of health policy.

Objective

The aim of the study was to validate a modified International Classification of Diseases (ICD)-10 based algorithm for identifying hospitalized patients with sepsis.

Methods

We retrospectively analyzed a prospective, single-center cohort of adult patients who were consecutively admitted to one medical ICU ward and ten non-ICU wards with suspected or confirmed infections during a 6-month period. A modified ICD-10 based algorithm was validated against a reference standard of Sequential Organ Failure Assessment (SOFA) score based on Sepsis-3. Sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), and areas under the receiver operating characteristic curves (AUROCs) were calculated for modified ICD-10 criteria, eSOFA criteria, Martin's criteria, and Angus's criteria.

Results

Of the 547 patients in the cohort, 332 (61%) patients met Sepsis-3 criteria and 274 (50%) met modified ICD-10 criteria. In the ICU setting, modified ICD-10 criteria had SE (84.47%), SP (88.57%), PPV (95.60), and NPV (65.96). In non-ICU settings, modified ICD-10 had SE (64.19%), SP (80.00%), PPV (80.33), and NPV (63.72). In the whole cohort, the AUROCs of modified ICD-10 criteria, eSOFA, Angus's criteria, and Martin's criteria were 0.76, 0.75, 0.62, and 0.62, respectively.

Conclusion

This study demonstrated that modified ICD-10 criteria had higher validity compared with Angus's criteria and Martin's criteria. Validity of the modified ICD-10 criteria was similar to eSOFA criteria. Modified ICD-10 algorithm can be used to provide an accurate estimate of population-based sepsis burden of China.

Bedside nurses' antimicrobial stewardship practice scope and competencies in acute hospital settings: A scoping review

AIM

To identify and map bedside nurses' practice scope and competencies regarding antimicrobial stewardship in acute hospital settings, and develop a competency framework for them.

BACKGROUND

Antimicrobial stewardship requires multidisciplinary engagement including nursing. However, bedside nurses' antimicrobial stewardship practice scope and competencies in acute hospital settings remain unclear.

DESIGN

Scoping review.

METHODS

Using a five-stage framework proposed by Arksey and O'Malley and following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines.

RESULTS

A total of 1422 records were retrieved, and 41 studies were included. In addition to the six practices recommended, this review summarized bedside nurses' contributions to five additional fields as well. Correspondingly, the competencies required by bedside nurses were summarized into eight domains: specialized knowledge, safety medication administration, leadership, education, diagnostic stewardship, infection prevention and control, professional development and professional quality.

CONCLUSION

Nurses' practice scope overlaps greatly with routine nursing practice in antimicrobial stewardship, confirming the evidence that nurses are ideal partners in antimicrobial stewardship. This review developed a competency framework at both basic and advanced levels. Among them, professional knowledge is the foundation, while professional quality motivates nurses to participate. In addition to competency assessment, it can also be used for training and human resource deployment based on seniority or professional level. This could bridge the knowledge gap and improve the engagement of nurses in heavy workload situations.

RELEVANCE TO CLINICAL PRACTICE

This practice scope will provide opportunities for nurses to engage in antimicrobial stewardship. Moreover, nursing competencies identified in this field could facilitate the development of competency-based education interventions, talent assessments, training and recruitment programs.

DATA RESOURCES

PubMed, EMBASE, Web of Science, CINHAL, PsycINFO, Cochrane Library, ProQuest and Scopus were searched from inception to November 2022, with an updated search in March 2023.

IMPACT

This scoping review provides evidence for best nursing practice scope and competency in antimicrobial stewardship in hospitals. However, it is also in line with the commitment of all nurses in the global community to combat antimicrobial resistance, which has become a global threat. An antimicrobial stewardship competency framework for bedside nurses was developed at both the basic and advanced levels. It would facilitate talent assessment, training, recruitment and human resource management by guiding the development of competency-based education interventions.

PATIENT OR PUBLIC CONTRIBUTION

No Patient or Public Contribution.

Understanding and Implementing Diagnostic Stewardship: A Guide for Resident Physicians in the Era of Antimicrobial Resistance

Antimicrobial resistance (AMR) poses a significant global health challenge, exacerbated by the COVID-19 pandemic. Antimicrobial stewardship programs (ASPs) are crucial in managing this crisis, with diagnostic stewardship (DS) emerging as a key component. DS refers to the appropriate use of diagnostic tests to optimize patient outcomes, improve antimicrobial use, and combat multi-drug-resistant (MDR) organisms. Despite its potential, understanding and application of DS remain ambiguous in multiple respects, which, however, do not directly implicate the implementation of such initiatives. DS is particularly important for resident physicians who are often at the forefront of patient care and can significantly influence future AMR strategies. This review provides a comprehensive overview of DS, discussing its importance, potential challenges, and future directions. It emphasizes the need for resident physicians to understand DS principles and integrate them into their clinical practice from the beginning of their careers. The review also highlights the role of various stakeholders in implementing DS and the importance of continuous education and training. Ultimately, DS is not just a clinical tool but a philosophy of care, essential for a more responsive, humane, and effective healthcare system.

Alternate Antimicrobial Therapies and Their Companion Tests

New antimicrobial approaches are essential to counter antimicrobial resistance. The drug development pipeline is exhausted with the emergence of resistance, resulting in unsuccessful trials. The lack of an effective drug developed from the conventional drug portfolio has mandated the introspection into the list of potentially effective unconventional alternate antimicrobial molecules. Alternate therapies with clinically explicable forms include monoclonal antibodies, antimicrobial peptides, aptamers, and phages. Clinical diagnostics optimize the drug delivery. In the era of diagnostic-based applications, it is logical to draw diagnostic-based treatment for infectious diseases. Selection criteria of alternate therapeutics in infectious diseases include detection, monitoring of response, and resistance mechanism identification. Integrating these diagnostic applications is disruptive to the traditional therapeutic development. The challenges and mitigation methods need to be noted. Applying the goals of clinical pharmacokinetics that include enhancing efficacy and decreasing toxicity of drug therapy, this review analyses the strong correlation of alternate antimicrobial therapeutics in infectious diseases. The relationship between drug concentration and the resulting effect defined by the pharmacodynamic parameters are also analyzed. This review analyzes the perspectives of aligning diagnostic initiatives with the use of alternate therapeutics, with a particular focus on companion diagnostic applications in infectious diseases.

Determinates of Clostridioides difficile infection (CDI) testing practices among inpatients with diarrhea at selected acute-care hospitals in Rochester, New York, and Atlanta, Georgia, 2020-2021

OBJECTIVE

We evaluated the impact of test-order frequency per diarrheal episodes on Clostridioides difficile infection (CDI) incidence estimates in a sample of hospitals at 2 CDC Emerging Infections Program (EIP) sites.

DESIGN

Observational survey.

SETTING

Inpatients at 5 acute-care hospitals in Rochester, New York, and Atlanta, Georgia, during two 10-workday periods in 2020 and 2021.

OUTCOMES

We calculated diarrhea incidence, testing frequency, and CDI positivity (defined as any positive NAAT test) across strata. Predictors of CDI testing and positivity were assessed using modified Poisson regression. Population estimates of incidence using modified Emerging Infections Program methodology were compared between sites using the Mantel-Hanzel summary rate ratio.

RESULTS

Surveillance of 38,365 patient days identified 860 diarrhea cases from 107 patient-care units mapped to 26 unique NHSN defined location types. Incidence of diarrhea was 22.4 of 1,000 patient days (medians, 25.8 for Rochester and 16.2 for Atlanta; P < .01). Similar proportions of diarrhea cases were hospital onset (66%) at both sites. Overall, 35% of patients with diarrhea were tested for CDI, but this differed by site: 21% in Rochester and 49% in Atlanta (P < .01). Regression models identified location type (ie, oncology or critical care) and laxative use predictive of CDI test ordering. Adjusting for these factors, CDI testing was 49% less likely in Rochester than Atlanta (adjusted rate ratio, 0.51; 95% confidence interval [CI], 0.40-0.63). Population estimates in Rochester had a 38% lower incidence of CDI than Atlanta (summary rate ratio, 0.62; 95% CI, 0.54-0.71).

CONCLUSION

Accounting for patient-specific factors that influence CDI test ordering, differences in testing practices between sites remain and likely contribute to regional differences in surveillance estimates.

Diagnostic stewardship for human immunodeficiency virus (HIV) testing using computerized physician order entry

Altering the appearance of a computerized physician order entry (CPOE) interface reduces misuse of an HIV diagnostic test by 87%, demonstrating that CPOE design is a key component of diagnostic stewardship. Collaboration between infectious disease providers, clinical laboratorians, and information technology (IT) professionals can result in improved quality and decreased costs.

Diagnostic Stewardship to Prevent Diagnostic Error

This Viewpoint discusses the growth of diagnostic stewardship beyond infectious disease to reduce diagnostic errors in other fields.

Leveraging diagnostic stewardship within antimicrobial stewardship programmes

Novel diagnostic stewardship in infectious disease consists of interventions that modify ordering, processing, and reporting of diagnostic tests to provide the right test for the right patient, prompting the right action. The interventions work upstream and synergistically with traditional antimicrobial stewardship efforts. As diagnostic stewardship continues to gain public attention, it is critical that antimicrobial stewardship programmes not only learn how to effectively leverage diagnostic testing to improve antimicrobial use but also ensure that they are stakeholders and leaders in developing new diagnostic stewardship interventions within their institutions. This review will discuss the need for diagnostic and antimicrobial stewardship, the interplay of diagnostic and antimicrobial stewardship, evidence of benefit to antimicrobial stewardship programmes, and considerations for successfully engaging in diagnostic stewardship interventions. This article is part of the Antibiotic stewardship Special Issue: https://www.drugsincontext.com/special_issues/antimicrobial-stewardship-a-focus-on-the-need-for-moderation.

Research frontiers and trends in the application of artificial intelligence to sepsis: A bibliometric analysis

Background

With the increasing interest of academics in the application of artificial intelligence to sepsis, thousands of papers on this field had been published in the past few decades. It is difficult for researchers to understand the themes and latest research frontiers in this field from a multi-dimensional perspective. Consequently, the purpose of this study is to analyze the relevant literature in the application of artificial intelligence to sepsis through bibliometrics software, so as to better understand the development status, study the core hotspots and future development trends of this field.

Methods

We collected relevant publications in the application of artificial intelligence to sepsis from the Web of Science Core Collection in 2000 to 2021. The type of publication was limited to articles and reviews, and language was limited to English. Research cooperation network, journals, cited references, keywords in this field were visually analyzed by using CiteSpace, VOSviewer, and COOC software.

Results

A total of 8,481 publications in the application of artificial intelligence to sepsis between 2000 and 2021 were included, involving 8,132 articles and 349 reviews. Over the past 22 years, the annual number of publications had gradually increased exponentially. The USA was the most productive country, followed by China. Harvard University, Schuetz, Philipp, and Intensive Care Medicine were the most productive institution, author, and journal, respectively. Vincent, Jl and Critical Care Medicine were the most cited author and cited journal, respectively. Several conclusions can be drawn from the analysis of the cited references, including the following: screening and identification of sepsis biomarkers, treatment and related complications of sepsis, and precise treatment of sepsis. Moreover, there were a spike in searches relating to machine learning, antibiotic resistance and accuracy based on burst detection analysis.

Conclusion

This study conducted a comprehensive and objective analysis of the publications on the application of artificial intelligence in sepsis. It can be predicted that precise treatment of sepsis through machine learning technology is still research hotspot in this field.

Antibacterial and Antifungal Properties of a Novel Antimicrobial Peptide GK-19 and Its Application in Skin and Soft Tissue Infections Induced by MRSA or Candida albicans

The increasing resistance of human pathogens promotes the development of novel antimicrobial agents. Due to the physical bactericidal mechanism of membrane disruption, antimicrobial peptides are considered as potential therapeutic candidates without inducing microbial resistance. Scorpion venom-derived peptide, Androctonus amoreuxi Antimicrobial Peptide 1 (AamAP1), has been proved to have broad-spectrum antimicrobial properties. However, AamAP1 can induce hemolysis and shows strong toxicity against mammalian cells. Herein, the antimicrobial activity and mechanism of a novel synthetic antimicrobial peptide, GK-19, derived from AamAP1 and its derivatives, was evaluated. Five bacteria and three fungi were used to evaluate the antimicrobial effects of GK-19 in vitro. Scalded mice models combined with skin and soft tissue infections (SSTIs) were used to evaluate its applicability. The results indicated that GK-19 could not only inhibit Gram-positive and Gram-negative bacterial growth, but also kill fungi by disrupting the microbial cell membrane. Meanwhile, GK-19 showed negligible toxicity to mammalian cells, low hemolytic activity and high stability in plasma. Furthermore, in scalded mice models combined with SSTIs induced by either Methicillin-Resistant Staphylococcus aureus (MRSA) or Candida albicans, GK-19 showed significant antimicrobial and healing effects. Overall, it was demonstrated that GK-19 might be a promising drug candidate in the battle against drug-resistant bacterial and fungal infections.

Outpatient Antibiotic and Antiviral Utilization Patterns in Patients Tested for Respiratory Pathogens in the United States: A Real-World Database Study

This retrospective observational study evaluated outpatient treatment patterns among patients with molecular-based viral diagnostic testing for suspected upper respiratory tract infections in the United States. Patients with a respiratory viral test were identified from 1 August 2016 to 1 July 2019 in a large national reference laboratory database linked to IQVIA’s prescription and medical claims databases. Antibiotic and influenza antiviral treatment patterns were reported up to 7 days post-test result. Predictors of antibiotic utilization were assessed using multivariable logistic regression. Among 9561 patients included in the study, 24.6% had evidence of ≥1 filled antibiotic prescription. Antibiotic utilization was higher in patients who tested negative for all viral targets (odds ratio [OR], 1.33; 95% confidence interval [CI], 1.17–1.50) and patients positive for non-influenza viruses (OR, 1.28; 95% CI, 1.09–1.51) compared with those influenza-positive only. Age ≥ 50 years and location outside of the northeast United States also predicted antibiotic utilization. Influenza antivirals were more common in influenza-positive patients compared with patients with other test results (32.5% vs. 3.6–9.0%). Thus, in this real-world study, antibiotic utilization was elevated in patients positive for non-influenza viruses, although antibiotics would generally not be indicated. Further research on pairing diagnostic tools with outpatient antibiotic stewardship programs is needed.

Effects of infectious disease consultation and antimicrobial stewardship program at a Japanese cancer center: An interrupted time-series analysis

In cancer patients, appropriate diagnosis and management of infection are frequently challenging owing to subtle or atypical presentation. We investigated the effectiveness of infectious disease (ID) consultations and the Antimicrobial Stewardship Program (ASP) in a Japanese cancer center. This 36-month-period, single-institution, interrupted time series analysis was retrospectively conducted during April 1, 2018–March 31, 2021, to evaluate a two-phase intervention: Phase 1 (notification of antimicrobials by the infection control team) and Phase 2 (establishing an ID consultation service and implementing ASP). Among 32,202 patients hospitalized, 22,096 and 10,106 hospitalizations occurred at baseline and during intervention period, respectively. The Antimicrobial Stewardship Team (AST) provided feedback on specific broad-spectrum antimicrobials in 913 instances (347 appropriate [38%]; 566 inappropriate [62%]), and 440 ID consultations were completed, with a 75% overall acceptance rate for AST suggestions. In Phase 2, monthly carbapenem days of therapy (CAR-DOT) decreased significantly, and narrow-spectrum antibiotic usage increased significantly in both trend and level; monthly DOT of antipseudomonal agents decreased significantly in trend. The results of these analyses of antimicrobial use are consistent with the DOT-based data based on antimicrobial use density (AUD). The total number of inpatient specimens increased significantly; the trend of multidrug-resistant Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus infections decreased, without changes in the incidence of other resistant organisms, all-cause in-hospital mortality, and length of stay. Actual and adjusted CAR purchase costs per patient-day decreased without significant changes in the actual and adjusted purchase cost per patient-day for all intravenous antimicrobials. Combining ID consultation and ASP reduced carbapenem use without negative patient outcomes. Their implementation could facilitate establishment of safe cancer treatment facilities in Japan and improve prognosis in cancer patients.

Accuracy of Direct Antimicrobial Susceptibility of Gram-Negative Bacteria from Positive Blood Cultures using MicroScan System and Value of Using Expert Rules for β-Lactam Agents

Direct antimicrobial susceptibility testing (AST) of positive blood cultures with Gram-negative bacteria produces results within 24 h, compared to 48 to 96 h with conventional methods. Positive clinical blood cultures were studied, supplemented with contrived blood cultures inoculated with a spectrum of resistant isolates. Bacterial inocula used for direct AST were quantitated. Direct AST was performed using MicroScan NM43 trays inoculated directly from positive blood cultures (100 μL in 25 mL water) and incubated using a WalkAway instrument, with trays read after 16 h. Reference AST was performed the following day from growth on solid medium using the same trays. Agreement of AST results between direct and reference methods, with and without the use of three expert rules for β-lactams, was evaluated using FDA categorical agreement criteria. Of 86 specimens tested (41 clinical specimens and 45 contrived specimens), the mean bacterial load in positive blood cultures was 8.98 log₁₀ CFU/mL. Fifteen isolates contained extended-spectrum β-lactamases, and 27 contained carbapenemases. Of 1,985 pairs of AST categorical results for 25 antimicrobials, 55.0% were susceptible, 4.7% intermediate, and 40.4% resistant by reference testing. Overall categorical agreement was 92.3%, with 5.3% minor errors, 1.9% major errors, and 0.4% very major errors. Agreement was higher for non-β-lactam agents (95.8%) than for β-lactam agents (90.3%; P < 0.0001). Application of expert rules increased agreement for β-lactam agents to 94.6%. The methods used achieved the study goal of producing accurate, cost-effective AST results directly from positive blood cultures using MicroScan trays with a 16-h incubation time without the need for additional testing. Use of three expert β-lactam rules improved accuracy.