The Antimicrobial Stewardship Approach to Combating Clostridium Difficile

A novel approach to correcting attribution of Clostridioides difficile in a healthcare setting

Objective

To describe a novel attribution metric estimating the causal source location of healthcare-associated Clostridioides difficile and compare it with the current US National Healthcare Safety Network (NHSN) surveillance reporting standard.

Design

Quality improvement study.

Setting

Two acute care facilities.

Methods

A novel attribution metric assigned days of attribution to locations where patients were located for 14 days before and the day of their C. difficile diagnosis. We correlated the NHSN-assigned unit attribution with the novel attribution measure and compared the proportion of attribution assigned to inpatient units.

Results

During a 30-month period, there were 727 NHSN C. difficile healthcare-associated infections (HAIs) and 409 non-HAIs; the novel metric attributed 17,034 days. The correlation coefficients for NHSN and novel attributions among non-ICU units were 0.79 (95% CI, 0.76-0.82) and 0.74 (95% CI, 0.70-0.78) and among ICU units were 0.70 (95% CI, 0.63-0.76) and 0.69 (95% CI, 0.60-0.77) at facilities A and B, respectively. The distribution of difference in percent attribution showed higher inpatient unit attribution using NHSN measure than the novel attribution metric: 38% of ICU units and 15% of non-ICU units in facility A, and 20% of ICU units and 25% of non-ICU units in facility B had a median difference >0; no inpatient units showed a greater attribution using the novel attribution metric.

Conclusion

The novel attribution metric shifts attribution from inpatient units to other settings and correlates modestly with NHSN methodology of attribution. If validated, the attribution metric may more accurately target C. difficile reduction efforts.

Antibiotic-induced collateral damage to the microbiota and associated infections

Antibiotics have transformed medicine, saving millions of lives since they were first used to treat a bacterial infection. However, antibiotics administered to target a specific pathogen can also cause collateral damage to the patient's resident microbial population. These drugs can suppress the growth of commensal species which provide protection against colonization by foreign pathogens, leading to an increased risk of subsequent infection. At the same time, a patient's microbiota can harbour potential pathogens and, hence, be a source of infection. Antibiotic-induced selection pressure can cause overgrowth of resistant pathogens pre-existing in the patient's microbiota, leading to hard-to-treat superinfections. In this Review, we explore our current understanding of how antibiotic therapy can facilitate subsequent infections due to both loss of colonization resistance and overgrowth of resistant microorganisms, and how these processes are often interlinked. We discuss both well-known and currently overlooked examples of antibiotic-associated infections at various body sites from various pathogens. Finally, we describe ongoing and new strategies to overcome the collateral damage caused by antibiotics and to limit the risk of antibiotic-associated infections.

Screening for Asymptomatic Clostridioides difficile Carriage Among Hospitalized Patients: A Narrative Review

Clostridioides difficile infection (CDI) has become the most common healthcare-associated infection in the United States, with considerable morbidity, mortality, and healthcare costs. Assessing new preventive strategies is vital. We present a literature review of studies evaluating a strategy of screening and isolation of asymptomatic carriers in hospital settings. Asymptomatic detection of C. difficile is reported in ~ 10-20% of admitted patients. Risk factors for carriage include recent hospitalization, previous antibiotics, older age, lower functional capacity, immunosuppression, and others. Asymptomatic C. difficile carriers of toxigenic strains are at higher risk for progression to CDI. They are also shedders of C. difficile spores and may contribute to the persistence and transmission of this bacterium. Screening for asymptomatic carriers at hospital admission can theoretically reduce CDI by isolating carriers to reduce transmission, and implementing antibiotic stewardship measures targeting carriers to prevent progression to clinical illness. Several observational studies, summarized in this review, have reported implementing screening and isolation strategies, and found a reduction in CDI rates. Nevertheless, the data are still limited to a few observational studies, and this strategy is not commonly practiced. Studies supporting screening were performed in North America, coinciding with the period of dominance of the 027/BI/NAP1 strain. Additional studies evaluating screening, followed by infection control and antibiotic stewardship measures, are needed.

Comparative analysis and trends in liver transplant hospitalizations with Clostridium difficile infections: A 10-year national cross-sectional study

GOALS AND BACKGROUND

Clostridium difficile infection (CDI) is the leading cause of antibiotic-associated diarrhea in the United States. We aimed to determine comparative trends in inpatient outcomes of liver transplant (LT) patients based on CDI during hospitalizations.

METHODS

The national inpatient sample database was used to conduct the present retrospective study regarding CDI among the LT hospitalizations from 2009 to 2019. Primary outcomes included 10-year comparative trends of the length of stay (LOS) and mean inpatient charges (MIC). Secondary outcomes included comparative mortality and LT rejection trends.

RESULTS

There was a 14.05% decrease in CDI in LT hospitalizations over the study period (p = .05). The trend in LOS did not significantly vary (p = .9). MIC increased significantly over the last decade in LT hospitalizations with CDI (p < .001). LT hospitalizations of autoimmune etiology compared against non-autoimmune did not increase association with CDI, adjusted odds ratio (aOR) 0.97 (95% confidence interval [CI] 0.75-1.26, p = .87). CDI was associated with increased mortality in LT hospitalizations, aOR 1.84 (95% CI 1.52-2.24, p < .001). In-hospital mortality for LT hospitalizations with CDI decreased by 7.75% over the study period (p = .3). CDI increased transplant rejections, aOR 1.3 (95% CI 1.08-1.65, p < .001). There was a declining trend in transplant rejection for LT hospitalization with CDI from 5% to 3% over the study period (p = .0048).

CONCLUSION

CDI prevalence does not increase based on autoimmune LT etiology. It increases mortality in LT hospitalizations; however, trend for mortality and transplant rejections has been declining over the last decade.

Risk Factors for Hospital Readmission for Clostridioides difficile Infection: A Statewide Retrospective Cohort Study

(1) Background: Clostridioides difficile infection (CDI) is associated with a high recurrence rate, and a significant proportion of patients with CDI are readmitted following discharge. We aimed to identify the risk factors for CDI-related readmission within 90 days following an index hospital stay for CDI. (2) Methods: We analyzed the electronic medical data of admitted patients in our health system over a two-year period. A multivariate logistic regression model, supplemented with bias-corrected and accelerated confidence intervals (BCa-CI), was implemented to assess the risk factors. (3) Results: A total of 1253 adult CDI index cases were included in the analysis. The readmission rate for CDI within 90 days of discharge was 11% (140/1253). The risk factors for CDI-related readmission were fluoroquinolone exposure within 90 days before the day of index CDI diagnosis (aOR: 1.58, 95% CI: 1.05–2.37), higher Elixhauser comorbidity score (aOR: 1.05, 95% CI: 1.02–1.07), and being discharged home (aOR: 1.64, 95% CI: 1.06–2.54). In contrast, a longer length of index stay (aOR: 0.97, 95% BCa-CI: 0.95–0.99) was associated with reduced odds of readmission for CDI. (4) Conclusion: More than 1 out of 10 patients were readmitted for CDI following an index hospital stay for CDI. Patients with recent previous fluoroquinolone exposure, greater overall comorbidity burden, and those discharged home are at higher risk of readmission for CDI.

Outcomes of clinical decision support for outpatient management of Clostridioides difficile infection

OBJECTIVE

To determine the impact of clinical decision support on guideline-concordant Clostridioides difficile infection (CDI) treatment.

DESIGN

Quasi-experimental study in >50 ambulatory clinics.

SETTING

Primary, specialty, and urgent-care clinics.

PATIENTS

Adult patients were eligible for inclusion if they were diagnosed with and treated for a first episode of symptomatic CDI at an ambulatory clinic between November 1, 2019, and November 30, 2020.

INTERVENTIONS

An outpatient best practice advisory (BPA) was implemented to notify prescribers that "vancomycin or fidaxomicin are preferred over metronidazole for C.difficile infection" when metronidazole was prescribed to a patient with CDI.

RESULTS

In total, 189 patients were included in the study: 92 before the BPA and 97 after the BPA. Their median age was 59 years; 31% were male; 75% were white; 30% had CDI-related comorbidities; 35% had healthcare exposure; 65% had antibiotic exposure; 44% had gastric acid suppression therapy within 90 days of CDI diagnosis. The BPA was accepted 23 of 26 times and was used to optimize the therapy of 16 patients in 6 months. Guideline-concordant therapy increased after implementation of the BPA (72% vs 91%; P = .001). Vancomycin prescribing increased and metronidazole prescribing decreased after the BPA. There was no difference in clinical response or unplanned encounter within 14 days after treatment initiation. Fewer patients after the BPA had CDI recurrence within 14-56 days of the initial episode (27% vs 7%; P < .001).

CONCLUSIONS

Clinical decision support increased prescribing of guideline-concordant CDI therapy in the outpatient setting. A targeted BPA is an effective stewardship intervention and may be especially useful in settings with limited antimicrobial stewardship resources.

Decreasing ICU-associated Clostridioides difficile infection through fluoroquinolone restriction, the FIRST trial: a study protocol

INTRODUCTION

Clostridioides difficile infection (CDI) is one of the most common healthcare-associated infections in the USA, having high incidence in intensive care units (ICU). Antibiotic use increases risk of CDI, with fluoroquinolones (FQs) particularly implicated. In healthcare settings, antibiotic stewardship (AS) and infection control interventions are effective in CDI control, but there is little evidence regarding the most effective AS interventions. Preprescription authorisation (PPA) restricting FQs is a potentially promising AS intervention to reduce CDI. The FQ Restriction for the Prevention of CDI (FIRST) trial will evaluate the effectiveness of an FQ PPA intervention in reducing CDI rates in adult ICUs compared with preintervention care, and evaluate implementation effectiveness using a human-factors and systems engineering model.

METHODS AND ANALYSIS

This is a multisite, stepped-wedge, cluster, effectiveness-implementation clinical trial. The trial will take place in 12 adult medical-surgical ICUs with ≥10 beds, using Epic as electronic health record (EHR) and pre-existing AS programmes. Sites will receive facilitated implementation support over the 15-month trial period, succeeded by 9 months of follow-up. The intervention comprises a clinical decision support system for FQ PPA, integrated into the site EHRs. Each ICU will be considered a single site and all ICU admissions included in the analysis. Clinical data will be extracted from EHRs throughout the trial and compared with the corresponding pretrial period, which will constitute the baseline for statistical analysis. Outcomes will include ICU-onset CDI rates, FQ days of therapy (DOT), alternative antibiotic DOT, average length of stay and hospital mortality. The study team will also collect implementation data to assess implementation effectiveness using the Systems Engineering Initiative for Patient Safety model.

ETHICS AND DISSEMINATION

The trial was approved by the Institutional Review Board at the University of Wisconsin-Madison (2018-0852-CP015). Results will be made available to participating sites, funders, infectious disease societies, critical care societies and other researchers.

TRIAL REGISTRATION NUMBER

NCT03848689.

The impact of intensive staff education on rate of Clostridium difficile-associated disease in hospitalized geriatric patients

BACKGROUND

Toxin-producing Clostridium difficile is the most common cause of nosocomial diarrhea in geriatric units.

AIM

The purpose of study was to check the impact of intensive staff education on rate of Clostridium difficile-associated disease in hospitalized geriatric patients.

METHODS

The sampling frame was all patients suffering from diarrhea checked for Clostridium difficile toxin during the years 2017-2018. Clostridium difficile-positive patients were compared to a similar number of Clostridium difficile toxin-negative patients. The data were compared to our previous study, followed by medical staff's educational program for Clostridium difficile control and prevention.

RESULTS

Among 217 patients with diarrhea, 60 (27.6%) were positive for Clostridium difficile toxin. The study group tended to be of older age (p = 0.06), and showed higher rate of functional impairment (p < 0.001) and mortality (p < 0.001) than Clostridium difficile toxin negative patients. The rate of Clostridium difficile toxin-positive patients did not significantly differ between the previous and current studies (20.0% and 27.6%, respectively).

CONCLUSIONS AND DISCUSSION

In spite of findings, that patients tended to be older, with high rate of mortality, the rate of Clostridium difficile did not change from the previous study.

Clostridioides difficile infection in US hospitals: a national inpatient sample study

BACKGROUND

Hypervirulent strains of Clostridioides difficile have altered the landscape of hospital and community outbreaks. We aim to examine and compare spatiotemporal trends, incidence, hospital teaching status, mortality, and cost associated with hospital-acquired Clostridioides difficile infection (HCDI) and community-acquired Clostridioides difficile infection (CCDI).

METHODS

Retrospective cohorts were studied using data from the Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) from 2006 to 2015.

RESULTS

A total of 76,124 cases of HCDI and 190,641 cases of CCDI were identified within the study period. The incidence of HCDI decreased from 8555 in 2006 to 7191 in 2015. Mortality also decreased during the same period (5.9% in 2006 to 1.4% 2015, p < 0.0001). Conversely, CCDI cases increased from 13,823 in 2006 to 20,637 in 2015. CCDI mortality decreased during the same period (4.3% in 2006 to 1.9% 2015, p < 0.0001). Rural hospital centers experienced the sharpest decline in HCDI mortality compared to urban and urban teaching centers (3.8%, p < 0.0001 vs 2.8%, p < 0.0001 vs 2.1%, p < 0.0001). Multivariate logistic regression indicated that increasing age (p = 0.0001), increasing hospital length of stay (p = 0.0001), and Medicare insurance (p = 0.002) were significant predictors of mortality for CDI mortality. Geospatial mapping of CCDI and HCDI revealed that the Eastern and Southern US experienced the largest incidence of CDI over 10 years.

CONCLUSION

The incidence of HCDI has decreased in the past decade while the incidence of CCDI hospitalization is sharply on the rise. While hospital length of stay and mortality has decreased over time, the cost of treating CDI remains high.

Toxigenic Clostridioides difficile colonization as a risk factor for development of C. difficile infection in solid-organ transplant patients

BACKGROUND

The association between Clostridioides difficile colonization and C. difficile infection (CDI) is unknown in solid-organ transplant (SOT) patients. We examined C. difficile colonization and healthcare-associated exposures as risk factors for development of CDI in SOT patients.

METHODS

The retrospective study cohort included all consecutive SOT patients with at least 1 screening test between May 2017 and April 2018. CDI was defined as the presence of diarrhea (without laxatives), a positive C. difficile clinical test, and the use of C. difficile-directed antimicrobial therapy as ordered by managing clinicians. In addition to demographic variables, exposures to antimicrobials, immunosuppressants, and gastric acid suppressants were evaluated from the time of first screening test to the time of CDI, death, or final discharge.

RESULTS

Of the 348 SOT patients included in our study, 33 (9.5%) were colonized with toxigenic C. difficile. In total, 11 patients (3.2%) developed CDI. Only C. difficile colonization (odds ratio [OR], 13.52; 95% CI, 3.46-52.83; P = .0002), age (OR, 1.09; CI, 1.02-1.17; P = .0135), and hospital days (OR, 1.05; 95% CI, 1.02-1.08; P = .0017) were independently associated with CDI.

CONCLUSIONS

Although CDI was more frequent in C. difficile colonized SOT patients, the overall incidence of CDI was low in this cohort.

Antimicrobial stewardship program achieved marked decrease in Clostridium difficile infections in a Veterans Hospital

Clostridium (or Clostridioides) difficile infection (CDI) is a common side effect of antimicrobial therapy and is increasingly linked with health care-associated transmissions. Antimicrobial stewardship programs (ASP) have demonstrated success in decreasing in-hospital CDI cases. We implemented an ASP targeting inappropriate or unnecessary use of all antibiotics especially empiric piperacillin-tazobactam and fluoroquinolone use. Concurrently, we monitored all health-care associated CDI. Our CDI cases were markedly decreased after initiation of our ASP.

Out of Sight-Out of Mind: Impact of Cascade Reporting on Antimicrobial Usage

Background

There is a paucity of data evaluating the strategy of suppressing broader-spectrum antibiotic susceptibilities on utilization. Cascade reporting (CR) is a strategy of reporting antimicrobial susceptibility test results in which secondary (eg, broader-spectrum, costlier) agents may only be reported if an organism is resistant to primary agents within a particular drug class. Our objective was to evaluate the impact of ceftriaxone-based cascade reporting on utilization of cefepime and clinical outcomes in patients with ceftriaxone-susceptible Escherichia and Klebsiella clinical cultures.

Methods

We compared post-CR (July 2014-June 2015) with baseline (July 2013-June 2014), evaluating utilization of cefepime, cefazolin, ceftriaxone, ampicillin derivatives, fluoroquinolones, piperacillin/tazobactam, ertapenem, and meropenem; new Clostridium difficile infection; and length of stay (LOS) after the positive culture, 30-day readmission, and in-hospital all-cause mortality.

Results

Mean days of therapy (DOT) among patients who received any antibiotic for cefepime decreased from 1.229 days during the baseline period to 0.813 days post-CR (adjusted relative risk, 0.668; P < .0001). Mean DOT of ceftriaxone increased from 0.864 days to 0.962 days, with an adjusted relative risk of 1.113 (P = .004). No significant differences were detected in other antibiotics including ertapenem and meropenem, demonstrating the direct association of the decrease in cefepime utilization with CR based on ceftriaxone susceptibility. Average LOS in the study population decreased from 14.139 days to 10.882 days from baseline to post-CR and was found to be statistically significant (P < .0001).

Conclusions

In conclusion, we demonstrated significant association of decreased cefepime utilization with the implementation of a CR based on ceftriaxone susceptibility. We demonstrated the safety of deescalation, with LOS being significantly lower during the post-CR period than in the baseline period, with no change in in-hospital mortality.

Understanding Clostridium difficile Colonization

Clostridium difficile is the main causative agent of antibiotic-associated and health care-associated infective diarrhea. Recently, there has been growing interest in alternative sources of C. difficile other than patients with Clostridium difficile infection (CDI) and the hospital environment. Notably, the role of C. difficile-colonized patients as a possible source of transmission has received attention. In this review, we present a comprehensive overview of the current understanding of C. difficile colonization. Findings from gut microbiota studies yield more insights into determinants that are important for acquiring or resisting colonization and progression to CDI. In discussions on the prevalence of C. difficile colonization among populations and its associated risk factors, colonized patients at hospital admission merit more attention, as findings from the literature have pointed to their role in both health care-associated transmission of C. difficile and a higher risk of progression to CDI once admitted. C. difficile colonization among patients at admission may have clinical implications, although further research is needed to identify if interventions are beneficial for preventing transmission or overcoming progression to CDI.

Controversies in Antimicrobial Stewardship: Focus on New Rapid Diagnostic Technologies and Antimicrobials

Antimicrobial stewardship programs (ASPs) are challenged with ensuring appropriate antimicrobial use while minimizing expenditures. ASPs have consistently demonstrated improved patient outcomes and significant cost reductions but are continually required to justify the costs of their existence and interventions due to the silo mentality often adopted by hospital administrators. As new technologies and antimicrobials emerge, ASPs are in a constant tug-of-war between providing optimal clinical outcomes and ensuring cost containment. Additionally, robust data on cost-effectiveness of new rapid diagnostic technologies and antimicrobials with subsequent ASP interventions to provide justification are lacking. As the implementation of an ASP will soon be mandatory for acute care hospitals in the United States, ASPs must find ways to justify novel interventions to align themselves with healthcare administrators. This review provides a framework for the justification of implementing a rapid diagnostic test or adding a new antimicrobial to formulary with ASP intervention, reviews approaches to demonstrating cost-effectiveness, and proposes methods for which ASPs may reduce healthcare expenditures via alternative tactics.