Effect of age on treatment outcomes in Clostridium difficile infection

Review article: The epidemiology and management of Clostridioides difficile infection-A clinical update

BACKGROUND

Clostridioides difficile is the most common cause of healthcare-associated infection, and severe cases can result in significant complications. While anti-microbial therapy is central to infection management, adjunctive therapies may be utilised as preventative strategies.

AIM

This article aims to review updates in the epidemiology, diagnosis, and management, including treatment and prevention, of C. difficile infections.

METHODS

A narrative review was performed to evaluate the current literature between 1986 and 2023.

RESULTS

The incidence of C. difficile infection remains significantly high in both hospital and community settings, though with an overall decline in recent years and similar surveillance estimates globally. Vancomycin and fidaxomicin remain the first line antibiotics for treatment of non-severe C. difficile infection, though due to lower recurrence rates, infectious disease society guidelines now favour use of fidaxomicin. Faecal microbiota transplantation should still be considered to prevent recurrent C. difficile infection. However, in the past year the field has had a significant advancement with the approval of the first two live biotherapeutic products-faecal microbiota spores-live brpk, an oral capsule preparation, and faecal microbiota live-jslm-both indicated for the prevention of recurrent C. difficile infection, with additional therapies on the horizon.

CONCLUSION

Although the prevalence of C. difficile infection remains high, there have been significant advances in the development of novel therapeutics and preventative measures following changes in recent practice guidelines, and will continue to evolve in the future.

The Strain and the Clinical Outcome of Clostridioides difficile Infection: A Meta-analysis

Background

The association between bacterial strains and clinical outcomes in Clostridioides difficile infection (CDI) has yielded conflicting results across studies. We conducted a systematic review and meta-analyses to assess the impact of these strains.

Methods

Five electronic databases were used to identify studies reporting CDI severity, complications, recurrence, or mortality according to strain type from inception to June 2022. Random effect meta-analyses were conducted to assess outcome proportions and risk ratios (RRs).

Results

A total of 93 studies were included: 44 reported recurrences, 50 reported severity or complications, and 55 reported deaths. Pooled proportions of complications were statistically comparable between NAP1/BI/R027 and R001, R078, and R106. Pooled attributable mortality was 4.8% with a gradation in patients infected with R014/20 (1.7%), R001 (3.8%), R078 (5.3%), and R027 (10.2%). Higher 30-day all-cause mortality was observed in patients infected with R001, R002, R027, and R106 (range, 20%-25%).NAP1/BI/R027 was associated with several unfavorable outcomes: recurrence 30 days after the end of treatment (pooled RR, 1.98; 95% CI, 1.02-3.84); admission to intensive care, colectomy, or CDI-associated death (1.88; 1.09-3.25); and 30-day attributable mortality (1.96; 1.23-3.13). The association between harboring the binary toxin gene and 30-day all-cause mortality did not reach significance (RR, 1.6 [0.9-2.9]; 7 studies).

Conclusions

Numerous studies were excluded due to discrepancies in the definition of the outcomes and the lack of reporting of important covariates. NAP1/BI/R027, the most frequently reported and assessed strain, was associated with unfavorable outcomes. However, there were not sufficient data to reach significant conclusions on other strains.

Efficacy and Health-Related Quality of Life Impact of Fecal Microbiota, Live-jslm: A Post Hoc Analysis of PUNCH CD3 Patients at First Recurrence of Clostridioides difficile Infection

INTRODUCTION

Clostridioides difficile infection (CDI) causes symptoms of varying severity and negatively impacts patients' health-related quality of life (HRQL). Despite antibiotic treatment, recurrence of CDI (rCDI) is common and imposes clinical and economic burdens on patients. Fecal microbiota, live-jslm (REBYOTA [RBL]) is newly approved in the USA for prevention of rCDI following antibiotic treatments. We analyzed efficacy and HRQL impact of RBL vs. placebo in patients at first rCDI using data from the phase 3 randomized, double-blind placebo-controlled clinical trial, PUNCH CD3.

METHODS

This post hoc analysis included patients at first rCDI fromPUNCH CD3. Treatment success (i.e., absence of diarrhea within 8 weeks post-treatment) was analyzed adjusting for baseline patient characteristics. HRQL was measured using the Clostridioides difficile Quality of Life Survey (Cdiff32); absolute scores and change from baseline in total and domain (physical, mental, and social) scores were summarized and compared between arms. Analyses were conducted for the trial's blinded phase only.

RESULTS

Among 86 eligible patients (32.8% of the overall trial population, RBL 53 [61.6%], placebo 33 [38.4%]), RBL-treated patients had significantly lower odds of recurrence (i.e., greater probability of treatment success) at week 8 vs. placebo (odds ratio 0.35 [95% confidence interval 0.13, 0.98]). Probability of treatment success at week 8 was 81% for RBL and 60% for placebo, representing 21% absolute and 35% relative increases for RBL (crude proportions 79.2% vs. 60.6%; relative risk 0.53, p = 0.06). Additionally, RBL was associated with significantly higher Cdiff32 total (change score difference 13.5 [standard deviation 5.7], p < 0.05) and mental domain (16.2 [6.0], p < 0.01) scores vs. placebo from baseline to week 8.

CONCLUSION

Compared to placebo, RBL demonstrated a significantly higher treatment success in preventing further rCDI and enhanced HRQL among patients at first recurrence, establishing RBL as an effective treatment to prevent further recurrences in these patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT03244644.

Interaction of Clostridioides difficile infection with frailty and cognition in the elderly: a narrative review

PURPOSE

Clostridioides difficile infection (CDI) is the leading cause of antibiotic-related diarrhea and healthcare-associated infections, affecting in particular elderly patients and their global health. This review updates the understanding of this infection, with focus on cognitive impairment and frailty as both risk factors and consequence of CDI, summarizing recent knowledge and potential mechanisms to this interplay.

METHODS

A literature search was conducted including terms that would incorporate cognitive and functional impairment, aging, quality of life, morbidity and mortality with CDI, microbiome and the gut-brain axis.

RESULTS

Advanced age remains a critical risk for severe disease, recurrence, and mortality in CDI. Observational and quality of life studies show evidence of functional loss in older people after acute CDI. In turn, frailty and cognitive impairment are independent predictors of death following CDI. CDI has long-term impact in the elderly, leading to increased risk of readmissions and mortality even months after the acute event. Immune senescence and the aging microbiota are key in susceptibility to CDI, with factors including inflammation and exposure to luminal microbial products playing a role in the gut-brain axis.

CONCLUSIONS

Frailty and poor health status are risk factors for CDI in the elderly. CDI affects quality of life, cognition and functionality, contributing to a decline in patient health over time and leading to early and late mortality. Narrative synthesis of the evidence suggests a framework for viewing the cycle of functional and cognitive decline in the elderly with CDI, impacting the gut-brain and gut-muscle axes.

Review of the Impact of Biofilm Formation on Recurrent Clostridioides difficile Infection

Clostridioides difficile infection (CDI) may recur in approximately 10-30% of patients, and the risk of recurrence increases with each successive recurrence, reaching up to 65%. C. difficile can form biofilm with approximately 20% of the bacterial genome expressed differently between biofilm and planktonic cells. Biofilm plays several roles that may favor recurrence; for example, it may act as a reservoir of spores, protect the vegetative cells from the activity of antibiotics, and favor the formation of persistent cells. Moreover, the expression of several virulence genes, including TcdA and TcdB toxins, has been associated with recurrence. Several systems and structures associated with adhesion and biofilm formation have been studied in C. difficile, including cell-wall proteins, quorum sensing (including LuxS and Agr), Cyclic di-GMP, type IV pili, and flagella. Most antibiotics recommended for the treatment of CDI do not have activity on spores and do not eliminate biofilm. Therapeutic failure in R-CDI has been associated with the inadequate concentration of drugs in the intestinal tract and the antibiotic resistance of a biofilm. This makes it challenging to eradicate C. difficile in the intestine, complicating antibacterial therapies and allowing non-eliminated spores to remain in the biofilm, increasing the risk of recurrence. In this review, we examine the role of biofilm on recurrence and the challenges of treating CDI when the bacteria form a biofilm.

Characteristics of Hospitalized Adults 55 and Older With Clostridioides difficile Infection

Clostridioides difficile infection in older adults can result in severe infection, difficulty in treating, and complicated disease process, yet few studies have examined the characteristics of hospitalized older adults and recurrent Clostridioides difficile infection. A retrospective cohort study was conducted to explore the characteristics of hospitalized adults 55 years and older with initial Clostridioides difficile infection and recurrences by extracting routinely documented data in the electronic health record. A sample of 1,199 admissions on 871 patients was included, with a recurrence rate of 23.9% ( n = 208). During the first admission, there were 79 deaths (9.1%). Clostridioides difficile infection recurrence was more prevalent in patients between 55 and 64 years old, and if discharged to a skilled nursing facility or with home health services. Chronic diseases significantly more prevalent in recurrent Clostridioides difficile infection included hypertension, heart failure, and chronic kidney disease. On initial admission, no laboratory abnormalities were significantly associated with recurrent Clostridioides difficile infection. This study indicates the need for utilizing routinely captured electronic health record data during acute hospitalizations to aid in targeting care to reduce morbidity, mortality, and recurrence.

Early Prognostic Stratification of Clostridioides difficile Infection in the Emergency Department: The Role of Age and Comorbidities

Clostridioides difficile infection (CDI) represents a significant cause of morbidity and mortality, mainly in older and frail subjects. Early identification of outcome predictors, starting from emergency department (ED) admission, could help to improve their management. In a retrospective single-center study on patients accessing the ED for diarrhea and hospitalized with a diagnosis of CDI infection, the patients’ clinical history, presenting symptoms, vital signs, and laboratory exams at ED admission were recorded. Quick sequential organ failure assessments (qSOFA) were conducted and Charlson’s comorbidity indices (CCI) were calculated. The primary outcomes were represented by all-cause in-hospital death and the occurrence of major cumulative complications. Univariate and multivariate Cox regression analyses were performed to establish predictive risk factors for poor outcomes. Out of 450 patients, aged > 81 years, dyspnea at ED admission, creatinine > 2.5 mg/dL, white blood cell count > 13.31 × 109/L, and albumin < 30 µmol/L were independently associated with in-hospital death and major complications (except for low albumin). Both in-hospital death and major complications were not associated with multimorbidity. In patients with CDI, the risk of in-hospital death and major complications could be effectively predicted upon ED admission. Patients in their 8th decade have an increased risk independent of comorbidities.

Impact of a pilot multimodal intervention to decrease antibiotic use for respiratory infections in a geriatric clinic

Background:

More than 80% of antibiotics are prescribed in the outpatient setting, of which 30% are inappropriate. The National Action Plan for Combating Antimicrobial Resistance called for a 50% decrease in outpatient antibiotic use by 2020. Inappropriate antibiotics are associated with adverse reactions and Clostridioides difficile infection, especially among older adults.

Study design:

Before and after study.

Methods:

We performed a quality improvement initiative at the University of Colorado Seniors Clinic. Providers received education on antibiotic guidelines, electronic antibiotic order sets were introduced with standardized stop dates. Antibiotic use data were collected for 6 months before and 6 months after the intervention, from December to May to avoid seasonal variation. Descriptive statistics and linear mixed-effects regression models were used for this comparison.

Results:

Total antibiotic prescriptions for acute respiratory conditions decreased from 137 prescriptions before the intervention (December 1, 2017, to May 31, 2018) to 112 prescriptions after the intervention (December 1, 2018, to May 31, 2019), driven primarily by decreases in antibiotic prescriptions for pneumonia, sinusitis, and bronchitis. Prescriptions for broad-spectrum antibiotics declined following the intervention including decreases in levofloxacin from 12 (9%) to 3 (3%) and amoxicillin-clavulanate from 15 (12%) to 7 (7%). We detected significant reductions in prescribed antibiotic durations (days) after the intervention for sinusitis (estimate, −2.0; 95% CI, −3.1 to −1.0; P = .0003), pharyngitis (estimate, −2.5; 95% CI, −4.6 to −0.5; P = .018), and otitis (−3.2; 95% CI, −5.2 to −1.3; P = .008).

Conclusions:

Low-cost interventions were initially successful in changing patterns of antibiotic use and decreasing overall antibiotic prescribing among older patients in the outpatient setting. Long-term follow-up studies are needed to determine the sustainability and clinical impact of these interventions.

European Society of Clinical Microbiology and Infectious Diseases: 2021 update on the treatment guidance document for Clostridioides difficile infection in adults

SCOPE

In 2009, the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) published the first treatment guidance document for Clostridioides difficile infection (CDI). This document was updated in 2014. The growing literature on CDI antimicrobial treatment and novel treatment approaches, such as faecal microbiota transplantation (FMT) and toxin-binding monoclonal antibodies, prompted the ESCMID study group on C. difficile (ESGCD) to update the 2014 treatment guidance document for CDI in adults.

METHODS AND QUESTIONS

Key questions on CDI treatment were formulated by the guideline committee and included: What is the best treatment for initial, severe, severe-complicated, refractory, recurrent and multiple recurrent CDI? What is the best treatment when no oral therapy is possible? Can prognostic factors identify patients at risk for severe and recurrent CDI and is there a place for CDI prophylaxis? Outcome measures for treatment strategy were: clinical cure, recurrence and sustained cure. For studies on surgical interventions and severe-complicated CDI the outcome was mortality. Appraisal of available literature and drafting of recommendations was performed by the guideline drafting group. The total body of evidence for the recommendations on CDI treatment consists of the literature described in the previous guidelines, supplemented with a systematic literature search on randomized clinical trials and observational studies from 2012 and onwards. The Grades of Recommendation Assessment, Development and Evaluation (GRADE) system was used to grade the strength of our recommendations and the quality of the evidence. The guideline committee was invited to comment on the recommendations. The guideline draft was sent to external experts and a patients' representative for review. Full ESCMID endorsement was obtained after a public consultation procedure.

RECOMMENDATIONS

Important changes compared with previous guideline include but are not limited to: metronidazole is no longer recommended for treatment of CDI when fidaxomicin or vancomycin are available, fidaxomicin is the preferred agent for treatment of initial CDI and the first recurrence of CDI when available and feasible, FMT or bezlotoxumab in addition to standard of care antibiotics (SoC) are preferred for treatment of a second or further recurrence of CDI, bezlotoxumab in addition to SoC is recommended for the first recurrence of CDI when fidaxomicin was used to manage the initial CDI episode, and bezlotoxumab is considered as an ancillary treatment to vancomycin for a CDI episode with high risk of recurrence when fidaxomicin is not available. Contrary to the previous guideline, in the current guideline emphasis is placed on risk for recurrence as a factor that determines treatment strategy for the individual patient, rather than the disease severity.

Prognostic factors for severe and recurrent Clostridioides difficile infection: a systematic review

OBJECTIVES

Clostridioides difficile infection (CDI), its subsequent recurrences (rCDIs), and severe CDI (sCDI) provide a significant burden for both patients and the healthcare system. Identifying patients diagnosed with initial CDI who are at increased risk of developing sCDI/rCDI could lead to more cost-effective therapeutic choices. In this systematic review we aimed to identify clinical prognostic factors associated with an increased risk of developing sCDI or rCDI.

METHODS

PubMed, Embase, Emcare, Web of Science and COCHRANE Library databases were searched from database inception through March, 2021. The study eligibility criteria were cohort and case-control studies. Participants were patients ≥18 years old diagnosed with CDI, in which clinical or laboratory factors were analysed to predict sCDI/rCDI. Risk of bias was assessed by using the Quality in Prognostic Research (QUIPS) tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool modified for prognostic studies. Study selection was performed by two independent reviewers. Overview tables of prognostic factors were constructed to assess the number of studies and the respective effect direction and statistical significance of an association.

RESULTS

136 studies were included for final analysis. Greater age and the presence of multiple comorbidities were prognostic factors for sCDI. Identified risk factors for rCDI were greater age, healthcare-associated CDI, prior hospitalization, proton pump inhibitors (PPIs) started during or after CDI diagnosis, and previous rCDI.

CONCLUSIONS

Prognostic factors for sCDI and rCDI could aid clinicians to make treatment decisions based on risk stratification. We suggest that future studies use standardized definitions for sCDI/rCDI and systematically collect and report the risk factors assessed in this review, to allow for meaningful meta-analysis of risk factors using data of high-quality trials.

Hospitalized Older Patients with Clostridioides difficile Infection Refractory to Conventional Antibiotic Therapy Benefit from Fecal Microbiota Transplant

Background:

Options for Clostridioides difficile infection (CDI) refractory to conventional therapy are limited. Fecal microbiota transplant (FMT) is considered safe and effective treatment for recurrent CDI and could be a treatment option for refractory CDI. We investigated the efficacy and safety of FMT in hospitalized patients who were not responding to standard treatments for CDI.

Methods:

Electronic medical records of patients who received FMT inpatient for refractory CDI were reviewed as part of quality improvement efforts to evaluate safety and efficacy of FMT in inpatient setting.

Results:

Between July 2014 and December 2019, 9 patients (age 60–96) received FMT for CDI as inpatient for refractory or fulminant CDI. Most (7 of 9) of these patients had pseudomembranous colitis and underwent multiple FMTs (mean 2.15, range 1 to 3). Five patients had complete resolution and one patient had diarrhea that was C. difficile-negative. There was one recurrent CDI and two deaths, one of which may have been related to FMT or CDI. Compared to recurrent CDI at diagnosis, patients with refractory CDI had higher WBC and neutrophil counts, which decreased after FMT. The overall cure rate of FMT in refractory cases was 66.7%.

Conclusions:

This study shows moderate efficacy of FMT for treatment of refractory CDI although multiple FMT treatment may need to be administered in the presence of pseudomembranous colitis. Inpatient FMT may be an alternative strategy for managing refractory CDI in this population of patients who may not have any effective medical treatment available.

Effectiveness of fidaxomicin versus oral vancomycin in the treatment of recurrent clostridioides difficile

WHAT IS KNOWN AND OBJECTIVE

The 2017 IDSA/SHEA Clinical Practice Guidelines for Clostridioides difficile infection (CDI) recommend treating recurrent episodes with fidaxomicin or oral vancomycin, but there is little evidence to support one strategy over another, particularly beyond the first recurrence. The aim of this study was to compare clinical outcomes in patients with recurrent CDI treated with vancomycin vs. fidaxomicin.

METHODS

This retrospective study evaluated inpatients with recurrent CDI treated with vancomycin or fidaxomicin between 1 January 2013 and 1 May 2019. The primary outcome was CDI recurrence. Secondary outcomes included re-infection, treatment failure, infection-related length of stay (IRLOS) and in-hospital all-cause mortality (IHACM). The Wilcoxon rank-sum test, Pearson's chi-square test or Fisher's exact test was utilized, as appropriate. A multivariable logistic regression (MLR) model was used to estimate the adjusted odds ratio and 95% confidence interval assessing recurrence while adjusting for confounding variables. A survival analysis was also conducted.

RESULTS

135 patients met the inclusion criteria (35 fidaxomicin vs. 100 vancomycin). There was no difference in CDI recurrence [7 (20%) fidaxomicin vs. 11 (11%) vancomycin, p = 0.18]; this persisted in the MLR model (OR: 0.85 [95% CI 0.27-2.7]) and survival analysis (p = 0.1954). Additionally, there was no difference in re-infection rate (p = 0.73), treatment failure (p = 0.13), IRLOS (p = 0.19) or IHACM (p = 0.65).

WHAT IS NEW AND CONCLUSION

This represents the first analysis of CDI recurrence that included patients with >2 prior episodes of CDI. The study found no difference in additional recurrences when patients were treated with oral vancomycin vs fidaxomicin for recurrent CDI. However, the current study is limited by the small sample size available for inclusion. Prospective randomized studies with larger sample sizes are needed to confirm this study's conclusions.

Real-life experience with fidaxomicin in Clostridioides difficile infection: a multicentre cohort study on 244 episodes

The high cost of fidaxomicin has restricted its use despite the benefit of a lower Clostridioides difficile infection (CDI) recurrence rate at 4 weeks of follow-up. This short follow-up represents the main limitation of pivotal clinical trials of fidaxomicin, and some recent studies question its benefits over vancomycin. Moreover, the main risk factors of recurrence after treatment with fidaxomicin remain unknown. We designed a multicentre retrospective cohort study among four Spanish hospitals to assess the efficacy of fidaxomicin in real life and to investigate risk factors of fidaxomicin failure at weeks 8 and 12. Two-hundred forty-four patients were included. Fidaxomicin was used in 96 patients (39.3%) for a first episode of CDI, in 95 patients (38.9%) for a second episode, and in 53 patients (21.7%) for a third or subsequent episode. Patients treated with fidaxomicin in a first episode were younger (59.9 years vs 73.5 years), but they had more severe episodes (52.1% vs. 32.4%). The recurrence rates for patients treated in the first episode were 6.5% and 9.7% at weeks 8 and 12, respectively. Recurrence rates increased for patients treated at second or ulterior episodes (16.3% and 26.4% at week 8, respectively). Age greater than or equal to 85 years and having had a previous episode of CDI were identified as recurrence risk factors at weeks 8 and 12. We conclude that the outcomes with fidaxomicin in real life are at least as good as those observed in clinical trials despite a more demanding evaluation. Be it 85 years of age or older, and the use after a first episode appears to be independent factors of CDI recurrence after treatment with fidaxomicin.

Teaching old mice new tricks: the utility of aged mouse models of C. difficile infection to study pathogenesis and rejuvenate immune response

BACKGROUND

Clostridioides difficile is a serious problem for the aging population. Aged mouse model of C. difficile infection (CDI) has emerged as a valuable tool to evaluate the mechanism of aging in CDI.

METHODS

We reviewed five published studies utilizing aged mice (7-28 months) for CDI model for findings that may advance our understanding of how aging influences outcome from CDI.

RESULTS

Aged mouse models of CDI uniformly demonstrated more severe disease in the old compared to young mice. Diminished neutrophil recruitment to intestinal tissue in aged mice is the most consistent finding. Differences in innate and humoral immune responses were also observed. The effects of aging on the outcome of infection were reversed by pharmacologic or microbiota-targeted interventions.

CONCLUSION

The aged mouse presents an important in vivo model to study CDI and elucidate the mechanisms underlying advanced age as an important risk factor for severe disease.

Changes in the Association between Diagnostic Testing Method, PCR Ribotype, and Clinical Outcomes from Clostridioides difficile Infection: One Institution's Experience

BACKGROUND

In patients with Clostridioides difficile infection (CDI), the relationship between clinical, microbial, and temporal/epidemiological trends relate and disease severity and adverse outcomes is incompletely understood. Here, in a follow-up to our study conducted in 2010-2013, we evaluate stool toxin levels and C. difficile PCR ribotypes. We hypothesized that elevated stool toxins and infection with ribotype 027 associate with severe disease and adverse outcomes.

METHODS

In a cohort of 565 subjects at the University of Michigan with CDI diagnosed by positive testing for toxins A/B by EIA or PCR for the tcdB gene, we quantified stool toxin levels via a modified cell cytotoxicity assay, isolated C. difficile by anaerobic culture, and performed PCR ribotyping. Severe CDI was defined by IDSA criteria, and primary outcomes were all-cause 30-day mortality and a composite of colectomy, ICU admission, and/or death attributable to CDI within 30 days. Analyses included bivariable tests and adjusted logistic regression.

RESULTS

199 samples were diagnosed by EIA and 447 were diagnosed by PCR. Toxin positivity associated with IDSA severity, but not primary outcomes. In 2016, compared to 2010-2013, ribotype 106 newly emerged, accounting for 10.6% of strains, ribotype 027 fell from 16.5% to 9.3%, and ribotype 014-027 remained stable at 18.9%. Ribotype 014-020 associated with IDSA severity and 30-day mortality (P=.001).

CONCLUSION

Toxin positivity by EIA and CCA associated with IDSA severity, but not with subsequent adverse outcomes. The molecular epidemiology of C. difficile has shifted, and this may have implications for the optimal diagnostic strategy for and clinical severity of CDI.

Human C. difficile toxin-specific memory B cell repertoires encode poorly neutralizing antibodies

Clostridioides difficile is a leading cause of nosocomial infection responsible for significant morbidity and mortality with limited options for therapy. Secreted C. difficile toxin B (TcdB) is a major contributor to disease pathology, and select TcdB-specific Abs may protect against disease recurrence. However, the high frequency of recurrence suggests that the memory B cell response, essential for new Ab production following C. difficile reexposure, is insufficient. We therefore isolated TcdB-specific memory B cells from individuals with a history of C. difficile infection and performed single-cell deep sequencing of their Ab genes. Herein, we report that TcdB-specific memory B cell–encoded antibodies showed somatic hypermutation but displayed limited isotype class switch. Memory B cell–encoded mAb generated from the gene sequences revealed low to moderate affinity for TcdB and a limited ability to neutralize TcdB. These findings indicate that memory B cells are an important factor in C. difficile disease recurrence.

The C. difficile toxin-specific human memory B cell repertoire encodes low-affinity, non-neutralizing antibodies.

[Updated review of Clostridium difficile infection in elderly]

Clostridium difficile infection is the most common cause of health care-associated diarrhoea, and its incidence increases with age. Clinical challenges, risk of resistance to treatment, risk of recurrence, and treatment responses are different in elderly. The aim of this review is to discuss the updated epidemiology, pathophysiology, diagnosis, and therapeutic management of C. difficile infection in elderly with the available data.

Incidence, Predictors, and Impact of Clostridium difficile Infection on Cardiac Surgery Outcomes

BACKGROUND

Clostridium difficile infection (CDI) has been associated with morbidity and mortality after cardiac operations. The present study examined incidence, predictors, and impact of CDI on inpatient mortality and resource utilization.

METHODS

An analysis of adult patients undergoing elective coronary artery bypass grafting or valvular operations from 2005 to 2016 was performed using the National Inpatient Sample. Trends in CDI were assessed using a modified Cochran-Armitage analysis. Multivariable multilevel regressions were used to identify predictors of CDI, and propensity-matched pairs were generated using Mahalanobis 1-to-1 matching to compare mortality, length of stay, and costs of CDI patients with the non-CDI cohort.

RESULTS

The overall rate of CDI for an estimated 2,026,267 patients who underwent elective major cardiac surgery was 0.5% with no change in incidence (P for trend = .99). Predictors of CDI included advanced age (≥65 y; adjusted odds ratio [AOR], 1.88; 95% confidence interval [CI], 1.58-2.24), female gender (AOR, 1.29; 95% CI, 1.15-1.44), heart failure (AOR, 1.57; 95% CI, 1.40-1.76), and combined coronary artery bypass grafting/valve operations (AOR, 1.60; 95% CI, 1.24-2.08). Neither region nor bed size was associated with CDI. In contrast CDI mortality was lower at teaching hospitals compared with rural hospitals. Among matched pairs CDI was independently associated with higher mortality, length of stay, and Gross Domestic Product-adjusted costs.

CONCLUSIONS

CDI occurs in less than 1% of all elective, major cardiac operations. Patient predictors included advanced age, female gender, and several chronic comorbidities. Teaching institutions had the highest odds of CDI but lowest odds of case fatality. Further investigation of factors contributing to CDI is warranted to disseminate institutional best practices.

Strategies to prevent adverse outcomes following Clostridioides difficile infection in the elderly

Introduction: Clostridioides difficile remains the most common cause of healthcare-associated infections in the US, and it disproportionately affects the elderly. Older patients are more susceptible and have a greater risk of adverse outcomes from C. difficile infection (CDI), despite advances in treatment and prevention.Areas covered: The epidemiology and pathogenesis of CDI, as well as risk factors in the aging host, will be reviewed. The importance of antimicrobial stewardship and infection prevention in order to avoid acquisition and transmission will be discussed, as well as strategies to prevent adverse outcomes and recurrent CDI, through optimization of CDI treatment s,election.Expert opinion: Appropriate CDI-prevention strategies to avoid adverse outcomes in this susceptible population involve antimicrobial stewardship and methods to prevent C. difficile transmission in healthcare settings. Management strategies to prevent adverse outcomes include initiation of supportive therapy and proper selection of CDI specific treatments. Many patients may also benefit from adjunctive therapies or additional procedures.

High Prevalence of Genetically Related Clostridium Difficile Strains at a Single Hemato-Oncology Ward Over 10 Years

Aims: Clostridium difficile (C. difficile) infection (CDI) is the main cause of healthcare-associated infectious diarrhea. We used whole-genome sequencing (WGS) to measure the prevalence and genetic variability of C. difficile at a single hemato-oncology ward over a 10 year period. Methods: Between 2008 and 2018, 2077 stool samples were obtained from diarrheal patients hospitalized at the Department of Lymphoma; of these, 618 were positive for toxin A/B. 140 isolates were then subjected to WGS on Ion Torrent PGM sequencer. Results: 36 and 104 isolates were recovered from 36 to 46 patients with single and multiple CDIs, respectively. Of these, 131 strains were toxigenic. Toxin gene profiles tcdA(+);tcdB(+);cdtA/cdtB(+) and tcdA(+);tcdB(+);cdtA/cdtB(-) were identified in 122 and nine strains, respectively. No isolates showed reduced susceptibility to metronidazole and vancomycin. All tested strains were resistant to ciprofloxacin, and 72.9, 42.9, and 72.9% of strains were resistant to erythromycin, clindamycin, or moxifloxacin, respectively. Multi-locus sequence typing (MLST) identified 23 distinct sequence types (STs) and two unidentified strains. Strains ST1 and ST42 represented 31 and 30.1% of all strains tested, respectively. However, while ST1 was detected across nearly all years studied, ST42 was detected only from 2009 to 2011. Conclusion: The high proportion of infected patients in 2008-2011 may be explained by the predominance of more transmissible and virulent C. difficile strains. Although this retrospective study was not designed to define outbreaks of C. difficile, the finding that most isolates exhibited high levels of genetic relatedness suggests nosocomial acquisition.

How to manage IBD in the 'elderly'

As the incidence of inflammatory bowel disease (IBD) rises and the global population ages, the number of older people living with these conditions will inevitably increase. The challenges posed by comorbid conditions, polypharmacy, the unintended consequences of long-term treatment and the real but often underestimated mismatch between chronological and biological ages underpin management. Significantly, there may be differences in disease characteristics, presentation and management of an older patient with IBD, together with other unique challenges. Importantly, clinical trials often exclude older patients, so treatment decisions are frequently pragmatic, extrapolated from a number of sources of evidence and perhaps primarily dictated by concerns around adverse effects. This review aimed to discuss the epidemiology, clinical features and considerations with management in older patients with IBD.

Extended-pulsed fidaxomicin versus vancomycin for Clostridium difficile infection in patients aged ≥60 years (EXTEND): analysis of cost-effectiveness

Objectives

The randomized Phase IIIb/IV EXTEND trial showed that extended-pulsed fidaxomicin significantly improved sustained clinical cure and reduced recurrence versus vancomycin in patients ≥60 years old with Clostridium difficile infection (CDI). Cost-effectiveness of extended-pulsed fidaxomicin versus vancomycin as first-line therapy for CDI was evaluated in this patient population.

Methods

Clinical results from EXTEND and inputs from published sources were used in a semi-Markov treatment-sequence model with nine health states and a 1 year time horizon to assess costs and QALYs. The model was based on a healthcare system perspective (NHS and Personal Social Services) in England. Sensitivity analyses were performed.

Results

Patients receiving first-line extended-pulsed fidaxomicin treatment had a 0.02 QALY gain compared with first-line vancomycin (0.6267 versus 0.6038 QALYs/patient). While total drug acquisition costs were higher for extended-pulsed fidaxomicin than for vancomycin when used first-line (£1356 versus £260/patient), these were offset by lower total hospitalization costs (which also included treatment monitoring and community care costs; £10 815 versus £11 459/patient) and lower costs of managing adverse events (£694 versus £1199/patient), reflecting the lower incidence of CDI recurrence and adverse events with extended-pulsed fidaxomicin. Extended-pulsed fidaxomicin cost £53 less per patient than vancomycin over 1 year. The probability that first-line extended-pulsed fidaxomicin was cost-effective at a willingness-to-pay threshold of £30 000/QALY was 76% in these patients.

Conclusions

While fidaxomicin acquisition costs are higher than those of vancomycin, the observed reduced recurrence rate with extended-pulsed fidaxomicin makes it a more effective and less costly treatment strategy than vancomycin for first-line treatment of CDI in older patients.

Acute Clostridioides difficile Infection in Hospitalized Persons Aged 75 and Older: 30-Day Prognosis and Risk Factors for Mortality

OBJECTIVES

To assess the 30-day mortality predictive markers in the oldest patients with Clostridioides difficile infection (CDI) and to analyze the accuracy of the European severity risk markers in this population.

DESIGN

Observational prospective multicenter cohort study conducted by the French Infectious Diseases Society and Geriatrics Society networks. An electronic questionnaire was sent to members of both societies regarding their participation. Each investigator used an online survey to gather the data.

SETTING AND PARTICIPANTS

Patients aged ≥75 years hospitalized in French geriatric or infectious wards with confirmed diagnosis of CDI between March 1, 2016 and May 1, 2017.

METHODS

Clinical and laboratory parameters included medical history and comorbidities with the Cumulative Illness Rating Scale (CIRS). Criteria increasing the risk of severe disease were recorded as listed in the European guidelines. Therapeutic management, recurrence, and mortality rates were assessed at day 30 after diagnosis.

RESULTS

Included patients numbered 247; mean age was 87.2 years (SD 5.4). Most of the CDI incidences (66.4%) were health care-associated infections, with 81% diagnosed within 30 days of hospitalization; CIRS mean score was 16.6 (SD 6.6). Markers of severity ≥3 included 97 patients (39.3%). Metronidazole was the main initial treatment (51.0%). C difficile infection in the older adult was associated with a 30-day mortality of 12.6%. Multivariate analysis showed that baseline CIRS score [hazard ratio (HR) 1.06 per 1-point increase, 95% confidence interval (CI) 1.00-1.12] and evidence of cardiac, respiratory, or renal decompensation (HR 3.04, 95% CI 1.40-6.59) were significantly associated with mortality.

CONCLUSIONS AND IMPLICATIONS

European severity markers are adequate in the oldest old. Organ failure and comorbidities appeared to be the main markers of prognosis, and these should raise the awareness of practitioners. Although antibiotic treatment was not predictive of mortality, our results point out the lack of adherence to current guidelines in this population.

Extended-pulsed fidaxomicin versus vancomycin for Clostridium difficile infection: EXTEND study subgroup analyses

Poor outcomes following Clostridium difficile infection (CDI) have been associated with advanced age, presence of cancer and C. difficile PCR-ribotype 027. The impact of baseline risk factors on clinical outcomes was evaluated using data from the EXTEND study, in which rate of sustained clinical cure (SCC) in the overall population was significantly higher with an extended-pulsed fidaxomicin (EPFX) regimen than with vancomycin. Patients aged ≥ 60 years received EPFX (fidaxomicin 200 mg twice daily, days 1–5; once daily on alternate days, days 7–25) or vancomycin (125 mg four times daily, days 1–10). We analysed outcomes by advanced age, cancer diagnosis, CDI severity, prior CDI occurrence and infection with PCR-ribotype 027. The primary endpoint was SCC 30 days after end of treatment (EOT; clinical response at test-of-cure with no subsequent recurrence). SCC rates 30 days after EOT did not differ significantly between EPFX (124/177, 70.1%) and vancomycin (106/179, 59.2%) regardless of age, cancer diagnosis, CDI severity and prior CDI. In patients with PCR-ribotype 027, SCC rate 30 days after EOT was significantly higher with EPFX (20/25, 80%) than with vancomycin (9/22, 40.9%) (treatment difference, 39.1%; 95% CI, 13.2–64.9; P = 0.006). Subgroup analyses from the EXTEND study suggest that EPFX is efficacious as a potential treatment for CDI regardless of age, cancer diagnosis, infection with PCR-ribotype 027, CDI severity or prior CDI. ClinicalTrials.gov identifier: NCT02254967.

Retrospective analysis of long-term gastrointestinal symptoms after Clostridium difficile infection in a nonelderly cohort

Elderly patients and those with comorbid conditions are at high risk for poor outcomes after Clostridium difficile infection (CDI) but outcomes in a healthier, nonelderly population are not well described. We sought to investigate gastrointestinal diagnoses and CDI during hospitalizations in the 24 to 36 months after an initial episode of CDI in nonelderly patients in a cohort with an overall low prevalence of comorbid conditions. We performed a retrospective analysis of hospital admissions from 2010–2013 using the Truven MarketScan database of employment-based private insurance claims. Subjects <65 years of age and their adult dependents (> = 18 years old); a CDI diagnosis in 2011 (index date); at least 12 months of pre-index continuous enrollment; and 24–36 months of continuous post-index enrollment were included. The 12 months of each subject’s enrollment prior to the index date for a CDI served as the reference period for the analyses of that subject’s post-CDI time periods. Hospital claims during the follow-up period were evaluated for gastrointestinal diagnoses and/or CDI ICD-9 codes. The risk of gastrointestinal diagnoses was assessed using Cox proportional hazards models adjusted for a pre-specified set of baseline demographic and clinical factors. During 2011, 5,632 subjects with CDI met the inclusion criteria for our study. The risk of gastrointestinal diagnoses in patients with a CDI diagnostic code for the same admission was almost 8-fold higher 3 months post-CDI (hazard ratio (HR) = 7.56; 95% confidence interval (CI): 2.97–19.19) than for subjects without CDI and remained statistically significant until month 24 (HR = 1.47; 95% CI = 1.04–2.08). After CDI, patients remained at risk for gastrointestinal symptoms with CDI for up to two years. There is an important, long-term healthcare burden after CDI in this population.

Fidaxomicin vs Vancomycin for the Treatment of a First Episode of Clostridium Difficile Infection: A Meta-analysis and Systematic Review

Clostridium difficile infection (CDI) continues to possess a significant disease burden in the United States (US) as well as all over the world. Given the increase in severity and recurrence rate, the decrease in cure rate, and the fact that the virulent ribotype 027 strain remains one of the most commonly identified strains in the US, the Infectious Diseases Society of America (IDSA) published a clinical practice guideline in February 2018 moving away from metronidazole as the first-line treatment for initial CDI and recommending either oral vancomycin or fidaxomicin. The aim of this study is to evaluate the clinical data available comparing the efficacy of primary treatment of CDI between those two antibiotics. We performed a PubMed, PubMed Central, and ScienceDirect database search without restriction to regions, publication types, or languages. A comprehensive literature search was performed from January 1, 1980 up to March 20, 2018. We used the following keywords in different combinations: Clostridium difficile, Clostridium difficile infection, CDI, C. diff, C. difficile, fidaxomicin, vancomycin, pseudomembranous colitis, and antibiotic-associated colitis. The search was limited to human studies. Data were independently extracted by two reviewers with disagreements resolved by a third author. We pooled an odds ratio (OR) on two primary outcomes: Clinical cure rate and rate of recurrence during the follow-up period. The computer search was also supplemented with manual searches by the authors of the retrieved review articles and primary studies. The search phrase “((Clostridium difficile) AND vancomycin) AND fidaxomicin” had the highest yield results. We identified four observational studies with a total of 2,303 patients with CDI that met our inclusion criteria. Compared with vancomycin, fidaxomicin use was associated with a significantly lower recurrence of CDI with a pooled OR of 0.47 (95% confidence interval (CI), 0.37 - 0.60, I2 = 0). On the other hand, there was no significant association of fidaxomicin use with CDI cure rate compared to vancomycin with a pooled OR of 1.22 (95% CI, 0.93 - 1.60, I2 = 0). In light of the recently updated clinical practice guidelines by the IDSA, our review suggests that fidaxomicin has a more sustained clinical response with a statistically significant lower recurrence rate. Although fidaxomicin appears to be the better drug with statistical significance, its cost-effectiveness continues to be an ongoing controversy. More randomized clinical trials are needed to shed light on this matter to assess if there is any clinical significance in fidaxomicin superiority.

Microbial Preparations (Probiotics) for the Prevention of Clostridium difficile Infection in Adults and Children: An Individual Patient Data Meta-analysis of 6,851 Participants

OBJECTIVETo determine whether probiotic prophylaxes reduce the odds of Clostridium difficile infection (CDI) in adults and children.DESIGNIndividual participant data (IPD) meta-analysis of randomized controlled trials (RCTs), adjusting for risk factors.METHODSWe searched 6 databases and 11 grey literature sources from inception to April 2016. We identified 32 RCTs (n=8,713); among them, 18 RCTs provided IPD (n=6,851 participants) comparing probiotic prophylaxis to placebo or no treatment (standard care). One reviewer prepared the IPD, and 2 reviewers extracted data, rated study quality, and graded evidence quality.RESULTSProbiotics reduced CDI odds in the unadjusted model (n=6,645; odds ratio [OR] 0.37; 95% confidence interval [CI], 0.25-0.55) and the adjusted model (n=5,074; OR, 0.35; 95% CI, 0.23-0.55). Using 2 or more antibiotics increased the odds of CDI (OR, 2.20; 95% CI, 1.11-4.37), whereas age, sex, hospitalization status, and high-risk antibiotic exposure did not. Adjusted subgroup analyses suggested that, compared to no probiotics, multispecies probiotics were more beneficial than single-species probiotics, as was using probiotics in clinical settings where the CDI risk is ≥5%. Of 18 studies, 14 reported adverse events. In 11 of these 14 studies, the adverse events were retained in the adjusted model. Odds for serious adverse events were similar for both groups in the unadjusted analyses (n=4,990; OR, 1.06; 95% CI, 0.89-1.26) and adjusted analyses (n=4,718; OR, 1.06; 95% CI, 0.89-1.28). Missing outcome data for CDI ranged from 0% to 25.8%. Our analyses were robust to a sensitivity analysis for missingness.CONCLUSIONSModerate quality (ie, certainty) evidence suggests that probiotic prophylaxis may be a useful and safe CDI prevention strategy, particularly among participants taking 2 or more antibiotics and in hospital settings where the risk of CDI is ≥5%.TRIAL REGISTRATIONPROSPERO 2015 identifier: CRD42015015701Infect Control Hosp Epidemiol 2018;771-781.

Clostridium difficile infection in the elderly: an update on management

The burden of Clostridium difficile infection (CDI) is profound and growing. CDI now represents a common cause of health care–associated diarrhea, and is associated with significant morbidity, mortality, and health care costs. CDI disproportionally affects the elderly, possibly explained by the following risk factors: age-related impairment of the immune system, increasing antibiotic utilization, and frequent health care exposure. In the USA, recent epidemiological studies estimate that two out of every three health care–associated CDIs occur in patients 65 years or older. Additionally, the elderly are at higher risk for recurrent CDI. Existing therapeutic options include metronidazole, oral vancomycin, and fidaxomicin. Choice of agent depends on disease severity, history of recurrence, and, increasingly, the drug cost. Bezlotoxumab, a recently approved monoclonal antibody targeting C. difficile toxin B, offers an exciting advancement into immunologic therapies. Similarly, fecal microbiota transplantation is gaining popularity as an effective option mainly for recurrent CDI. The challenge of decreasing CDI burden in the elderly involves adopting preventative strategies, optimizing initial treatment, and decreasing the risk of recurrence. Expanded strategies are certainly needed to improve outcomes in this high-risk population. This review considers available data from prospective and retrospective studies as well as case reports to illustrate the merits and gaps in care related to the management of CDI in the elderly.

Collateral damage during antibiotic treatment of C. difficile infection in the aged host: Insights into why recurrent disease happens

Clostridium difficile infection (CDI) is one of the most common causes of healthcare-associated infections but an even bigger problem for the aging population. Advanced age leads to higher incidence, higher mortality, and higher recurrences. In our study, recently published in the Journal of Infectious Diseases, we investigated the effect of aging on CDI using a mouse model. We were able to demonstrate that aging leads to worse clinical outcomes, as well as lead to changes in microbiota composition and lower antibody production against C. difficile toxin A, but not toxin B. An association between advanced age and lower antibody production against C. difficile is a new finding which would explain the effect of aging on CDI outcome. Vancomycin, an anti-C. difficile antibiotic, led to similar changes in antibody response, suggesting a connection between microbiome and antibody response in the context of aging, which would require a much more nuanced look at the treatment of CDI.

Recognition and management of Clostridium difficile in older adults

Clostridium difficile infection (CDI) is increasing in the outpatient setting, and older adults are at a higher risk for contracting CDI and experiencing poor outcomes. NPs may see this infection in the primary care setting. This article focuses on the presentation, treatment, and clinical practice implications for CDI in community-dwelling older adults.

Efficacy and safety of ridinilazole compared with vancomycin for the treatment of Clostridium difficile infection: a phase 2, randomised, double-blind, active-controlled, non-inferiority study

BACKGROUND

Clostridium difficile infection is the most common health-care-associated infection in the USA. We assessed the safety and efficacy of ridinilazole versus vancomycin for treatment of C difficile infection.

METHODS

We did a phase 2, randomised, double-blind, active-controlled, non-inferiority study. Participants with signs and symptoms of C difficile infection and a positive diagnostic test result were recruited from 33 centres in the USA and Canada and randomly assigned (1:1) to receive oral ridinilazole (200 mg every 12 h) or oral vancomycin (125 mg every 6 h) for 10 days. The primary endpoint was achievement of a sustained clinical response, defined as clinical cure at the end of treatment and no recurrence within 30 days, which was used to establish non-inferiority (15% margin) of ridinilazole versus vancomycin. The primary efficacy analysis was done on a modified intention-to-treat population comprising all individuals with C difficile infection confirmed by the presence of free toxin in stool who were randomly assigned to receive one or more doses of the study drug. The study is registered with ClinicalTrials.gov, number NCT02092935.

FINDINGS

Between June 26, 2014, and August 31, 2015, 100 patients were recruited; 50 were randomly assigned to receive ridinilazole and 50 to vancomycin. 16 patients did not complete the study, and 11 discontinued treatment early. The primary efficacy analysis included 69 patients (n=36 in the ridinilazole group; n=33 in the vancomycin group). 24 of 36 (66·7%) patients in the ridinilazole group versus 14 of 33 (42·4%) of those in the vancomycin group had a sustained clinical response (treatment difference 21·1%, 90% CI 3·1-39·1, p=0·0004), establishing the non-inferiority of ridinilazole and also showing statistical superiority at the 10% level. Ridinilazole was well tolerated, with an adverse event profile similar to that of vancomycin: 82% (41 of 50) of participants reported adverse events in the ridinilazole group and 80% (40 of 50) in the vancomycin group. There were no adverse events related to ridinilazole that led to discontinuation.

INTERPRETATION

Ridinilazole is a targeted-spectrum antimicrobial that shows potential in treatment of initial C difficile infection and in providing sustained benefit through reduction in disease recurrence. Further clinical development is warranted.

FUNDING

Wellcome Trust and Summit Therapeutics.

Therapeutic interventions for gut dysbiosis and related disorders in the elderly: antibiotics, probiotics or faecal microbiota transplantation?

Ageing and physiological functions of the human body are inversely proportional to each other. The gut microbiota and host immune system co-evolve from infants to the elderly. Ageing is accompanied by a decline in gut microbial diversity, immunity and metabolism, which increases susceptibility to infections. Any compositional change in the gut is directly linked to gastrointestinal disorders, obesity and metabolic diseases. Increase in opportunistic pathogen invasion in the gut like Clostridium difficile leading to C. difficile infection is more common in the elderly population. Frequent hospitalisation and high prevalence of nosocomial infections with the ageing is also well documented. Long-term utilisation of broad-spectrum antibiotic therapy is being followed in order to control these infections. Nosocomial infections and antibiotic therapy in combination or alone is leading to gastroenteritis followed by Clostridium associated diarrhoea or antibiotic associated diarrhoea. Above all, use of broad-spectrum antibiotics is highly debated all over the world due to growing antimicrobial resistance. The use of narrow spectrum antibiotics could be helpful to some extent. Dietary supplementation of probiotics with prebiotics (synbiotics) or without prebiotics has improved gut commensal diversity and regulated the immune system. The recent emergence of faecal microbiota transplantation has played an important role in treating recurrent Clostridium associated diarrhoea. This review focuses on various therapeutic interventions for gut dysbiosis and gastrointestinal diseases in the elderly. The possible mechanism for antimicrobial resistance and mechanism of action of probiotics are also discussed in detail.

Asymptomatic and yet C. difficile-toxin positive? Prevalence and risk factors of carriers of toxigenic Clostridium difficile among geriatric in-patients

Background

Clostridium difficile infections (CDI) are the most frequent cause of diarrhoea in hospitals. Geriatric patients are more often affected by the condition, by a relapse and complications. Therefore, a crucial question is how often colonization with toxigenic Clostridium difficile strains occurs in elderly patients without diarrhoea and whether there is a “risk pattern” of colonized patients that can be defined by geriatric assessment. Furthermore, the probability for those asymptomatic carriers to develop a symptomatic infection over time has not been sufficiently explored.

Methods

We performed a cohort study design to assess the association of clinical variables with Clostridium difficile colonization. The first stool sample of 262 consecutive asymptomatic patients admitted to a geriatric unit was tested for toxigenic Clostridium difficile using PCR (GeneXpert, Cepheid). A comprehensive geriatric assessment (CGA) including Barthel Index, Mini Mental State Examination (MMSE) and hand grip-strength was performed. In addition, Charlson Comorbidity Index, body mass index, number and length of previous hospital stays, previous treatment with antibiotics, institutionalization, primary diagnoses and medication were recorded and evaluated as possible risk factors of colonization by means of binary logistic regression. Secondly, we explored the association of C. difficile colonization with subsequent development of CDI during hospital stay.

Results

At admission, 43 (16.4%) patients tested positive for toxin B by PCR. Seven (16.3%) of these colonized patients developed clinical CDI during hospital stay, compared to one out of 219 patients with negative or invalid PCR testing (Odds ratio 12,3; Fisher’s exact test: p = 0.000). Overall, 7 out of 8 (87.5%) CDI patients had been colonized at admission. Risk factors of colonization with C. difficile were a history of CDI, previous antibiotic treatment and hospital stays. The parameters of the CGA were not significantly associated with colonization.

Conclusion

Colonization with toxigenic Clostridium difficile strains occurs frequently in asymptomatic patients admitted to a geriatric unit. Previous CDI, antibiotic exposure and hospital stay, but not clinical variables such as CGA, are the main factors associated with asymptomatic Clostridium difficile carriage. Colonization is a crucial risk factor for subsequent development of symptomatic CDI.

Ridinilazole: a novel therapy for Clostridium difficile infection

Clostridium difficile infection (CDI) is the leading cause of infectious healthcare-associated diarrhoea. Recurrent CDI increases disease morbidity and mortality, posing a high burden to patients and a growing economic burden to the healthcare system. Thus, there exists a significant unmet and increasing medical need for new therapies for CDI. This review aims to provide a concise summary of CDI in general and a specific update on ridinilazole (formerly SMT19969), a novel antibacterial currently under development for the treatment of CDI. Owing to its highly targeted spectrum of activity and ability to spare the normal gut microbiota, ridinilazole provides significant advantages over metronidazole and vancomycin, the mainstay antibiotics for CDI. Ridinilazole is bactericidal against C. difficile and exhibits a prolonged post-antibiotic effect. Furthermore, treatment with ridinilazole results in decreased toxin production. A phase 1 trial demonstrated that oral ridinilazole is well tolerated and specifically targets clostridia whilst sparing other faecal bacteria. Phase 2 and 3 trials will hopefully further our understanding of the clinical utility of ridinilazole for the treatment of CDI.

Older Is Not Wiser, Immunologically Speaking: Effect of Aging on Host Response to Clostridium difficile Infections

Clostridium difficile infection (CDI) is the most common cause of antibiotic-associated diarrhea and a significant burden on the health care system. Aging has been identified in the literature as a risk factor for CDI as well as adverse outcome from CDI. Although this effect of advanced age on CDI could be partially explained by clinical factors associated with aging, biologic factors are important. Innate immune system, responsible for immediate response to acute infections, plays a major role in CDI pathogenesis. Impairment in function of innate immunity with aging, demonstrated in other infection models, may lead to worse outcome with CDI. C. difficile toxin-specific antibody response protects the host against initial and recurrent infections as shown in observational studies and clinical trial. Effect of aging on antibody response to CDI has not been demonstrated, but the results from vaccine studies in other infections suggest a negative effect on humoral immunity from aging. Although intestinal microbiota from healthy people confers resistance to CDI by preventing C. difficile colonization, changes in composition of microbiota with aging may affect that resistance and increase risk for CDI. There are also age-associated changes in physiology, especially of the gastrointestinal tract, that may play a role in CDI risk and outcomes. In this review, we will first discuss the epidemiology of CDI in the elderly people, then the alteration in innate immunity, humoral response, and microbiota that increases susceptibility to CDI and severe disease and lastly, the physiological and functional changes that may modify outcomes of infection.

Prevention of Clostridium difficile Infection: A Systematic Survey of Clinical Practice Guidelines

BACKGROUND Clostridium difficile infection (CDI) is the most common cause of hospital-acquired infectious diarrhea. OBJECTIVE To analyze the methodological quality, content, and supporting evidence among clinical practice guidelines (CPGs) on CDI prevention. DESIGN AND SETTING We searched medical databases and gray literature for CPGs on CDI prevention published January 2004-January 2015. Three reviewers independently screened articles and rated CPG quality using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument, composed of 23 items, rated 1-7, within 6 domains. We reported each domain score as a percentage of its maximum possible score and standardized range. We summarized recommendations, extracted their supporting articles, and rated individually the level of evidence using the Oxford Centre for Evidence-Based Medicine Levels of Evidence. RESULTS Of 2,578 articles screened, 5 guidelines met inclusion criteria. Median AGREE II scores and interquartile ranges were: clarity of presentation, 75.9% (75.9%-79.6%); scope and purpose, 74.1% (68.5%-85.2%); editorial independence, 63.9% (47.2%-66.7%); applicability, 43.1% (19.4%-55.6%); stakeholder involvement, 40.7% (38.9%-44.4%); and rigor of development, 18.1% (17.4%-35.4%). CPGs addressed several common strategies for CDI prevention, including antibiotic stewardship, hypochlorite solutions, probiotic prophylaxis, and bundle strategies. Recommendations were often not consistent with evidence, and most were based on low-level studies. CONCLUSION CPGs did not adhere well to AGREE II reporting standards. Furthermore, there was limited transparency in moving from evidence to recommendations. CDI prevention CPGs need to better adhere to AGREE-II and be transparent in moving from evidence to recommendations, and recommendations need to be consistent with available evidence. Infect Control Hosp Epidemiol 2016;37:901-908.

Fecal microbiota transplant for Clostridium difficile infection in older adults

BACKGROUND

The objective of this study was to describe the safety of fecal microbiota transplant (FMT) for Clostridium difficile infection (CDI) among older adults.

METHODS

We performed a case review of all FMT recipients aged 65 or older treated at Emory University Hospital, a tertiary care and referral center for Georgia and surrounding states.

RESULTS

CDI resolved in 27 (87%) of 31 respondents, including three individuals who received multiple FMTs. Among four whose CDI was not resolved at follow up, three respondents did well initially before CDI recurred, and one individual never eradicated his CDI despite repeating FMT. During the study, five deaths and eight serious adverse events requiring hospitalization were reported within the study group during the follow-up period. Fecal transplant was not a causative factor in these events. The most common adverse event reported in 4 (13%) of 31 respondents was subjective worsening of arthritis.

CONCLUSION

FMT is a generally safe and effective treatment option for older adults with CDI.

The Long-term Efficacy and Safety of Fecal Microbiota Transplant for Recurrent, Severe, and Complicated Clostridium difficile Infection in 146 Elderly Individuals

OBJECTIVES

Clostridium difficile infection (CDI) in the elderly has a higher prevalence, greater morbidity and mortality, and lower response to conventional treatment than the general population. Fecal microbiota transplant (FMT) is highly effective therapy for CDI but has not been studied specifically in the elderly. This study aims to determine the long-term efficacy and safety of FMT for recurrent (RCDI), severe (SCDI), and complicated (CCDI) CDI in elderly patients.

METHODS

A multicenter, long-term follow-up study was performed with demographic, pre-FMT, and post-FMT data collected from elderly patients with RCDI, SCDI, and CCDI, through a 47-item questionnaire. Outcome measures included primary and secondary cure rates, early (<12 wk) and late (≥12 wk) recurrence rates, and adverse events (AEs), including post-FMT diagnoses.

RESULTS

Of 168 eligible patients, 146 patients met the inclusion criteria. Of these, 68.5% were women. The mean (range) age was 78.6 (65 to 97) years and the follow-up period was 12.3 (1 to 48) months. FMT was performed for RCDI in 89 (61%), SCDI in 45 (30.8%), and CCDI in 12 (8.2%) patients. The primary and secondary cure rates were 82.9% and 95.9%, respectively. Early and late recurrences occurred in 25 and 6 patients, respectively. AEs included CDI-negative diarrhea in 7 (4.8%) and constipation in 4 (2.7%) patients. Serious AEs, recorded in 6 patients, were hospital admissions for CDI-related diarrhea, one of which culminated in death. New diagnoses post-FMT included microscopic colitis (2), Sjogren syndrome (1), follicular lymphoma (1), contact dermatitis and idiopathic Bence-Jones proteinuria (1), and laryngeal carcinoma (1)-all, however, were associated with predisposing factors.

CONCLUSIONS

FMT is a safe and effective treatment option for RCDI, SCDI, and CCDI in elderly patients.

Fidaxomicin--the new drug for Clostridium difficile infection

Clostridium difficile is one of the many aetiological agents of antibiotic associated diarrhoea and is implicated in 15-25 per cent of the cases. The organism is also involved in the exacearbation of inflammatory bowel disease and extracolonic manifestations. Due to increase in the incidence of C. difficile infection (CDI), emergence of hypervirulent strains, and increased frequency of recurrence, the clinical management of the disease has become important. The management of CDI is based on disease severity, and current antibiotic treatment options are limited to vancomycin or metronidazole in the developing countries. this review article briefly describes important aspects of CDI, and the new drug, fidaxomicin, for its treatment. Fidaxomicin is particularly active against C. difficile and acts by inhibition of RNA synthesis. Clinical trials done to compare the efficacy and safety of fidaxomicin with that of vancomycin in treating CDI concluded that fidaxomicin was non-inferior to vancomycin for treatment of CDI and that there was a significant reduction in recurrences. The bactericidal properties of fidaxomicin make it an ideal alternative for CDI treatment. However, fidaxomicin use should be considered taking into account the potential benefits of the drug, along with the medical requirements of the patient, the risks of treatment and the high cost of fidaxomicin compared to other treatment regimens.

Clostridium difficile recurrences in Stockholm

Sixty-eight hospital-admitted patients with a first episode of Clostridium difficile infection (CDI) were included and followed up during 1 year. Faeces samples were collected at 1, 2, 6 and 12 months after inclusion and analyzed for the presence of C. difficile toxin B, genes for toxin A, toxin B, binary toxin and TcdC deletion by PCR. All strains were also PCR-ribotyped and the MICs of the isolates were determined against eight antimicrobial agents. In 68 patients initially included, antibiotics, clinical signs and co-morbidities were analyzed and 56 were evaluable for recurrences. The mean number of different antibiotics given during 3 months prior to inclusion was 2.6 (range 0-6). Six patients had not received any antibiotics and three of them had diagnosed inflammatory bowel disease. Thirty-two patients (57%) had either a microbiological or clinical recurrence, 16 of whom had clinical recurrences that were confirmed microbiologically (13, 23%) or unconfirmed by culture (3, 5%). Twenty-nine patients were positive in at least one of the follow-up tests, 16 had the same ribotype in follow-up tests, i.e. relapse, and 13 a different ribotype, i.e., reinfection. Most common ribotypes were 078/126, 020, 023, 026, 014/077, 001 and 005. No strain of ribotype 027 was found. Strains ribotype 078/126 and 023 were positive for binary toxin and were the strains most prone to cause recurrence. All strains were sensitive to vancomycin and metronidazole. Patients with recurrences were significantly older (p = 0.02) and all patients had a high burden of comorbidities, which could explain the high fatality rate, 26 (38%) patients died during the 1-year follow-up.

Vancomycin Treatment Alters Humoral Immunity and Intestinal Microbiota in an Aged Mouse Model of Clostridium difficile Infection

BACKGROUND

The elderly host is highly susceptible to severe disease and treatment failure in Clostridium difficile infection (CDI). We investigated how treatment with vancomycin in the aged host influences systemic and intestinal humoral responses and select intestinal microbiota.

METHODS

Young (age, 2 months) and aged (age, 18 months) C57BL/6 mice were infected with VPI 10463 after exposure to broad-spectrum antibiotics. Vancomycin was given 24 hours after infection, and treatment was continued for 5 days. At select time points, specimens of serum and intestinal tissue and contents were collected for histopathologic analysis, to measure antibody levels and the pathogen burden, and to determine the presence and levels of select intestinal microbiota and C. difficile toxin.

RESULTS

Levels of disease severity, relapse, and mortality were increased, and recovery from infection was slower in aged mice compared to young mice. Serum levels of immunoglobulin M, immunoglobulin A, and immunoglobulin G against C. difficile toxin A were depressed in aged mice, and vancomycin treatment reduced antibody responses in both age groups. While baseline levels of total bacterial load, Bacteroidetes, Firmicutes, and Enterobacteriaceae were mostly similar, aged mice had a significant change in the Firmicutes to Bacteroidetes ratio with vancomycin treatment.

CONCLUSIONS

Vancomycin treatment decreases the systemic humoral response to CDI. Increased mortality from and recurrence of CDI in the aged host are associated with an impaired humoral response and a greater susceptibility to vancomycin-induced alteration of intestinal microbiota.

Elderly patients and inflammatory bowel disease

The incidence and prevalence of inflammatory bowel disease (IBD) is increasing globally. Coupled with an ageing population, the number of older patients with IBD is set to increase. The clinical features and therapeutic options in young and elderly patients are comparable but there are some significant differences. The wide differential diagnosis of IBD in elderly patients may result in a delay in diagnosis. The relative dearth of data specific to elderly IBD patients often resulting from their exclusion from pivotal clinical trials and the lack of consensus guidelines have made clinical decisions somewhat challenging. In addition, age specific concerns such as co-morbidity; loco-motor and cognitive function, poly-pharmacy and its consequences need to be taken into account. In applying modern treatment paradigms to the elderly, the clinician must consider the potential for more pronounced adverse effects in this vulnerable group and set appropriate boundaries maximising benefit and minimising harm. Meanwhile, clinicians need to make personalised decisions but as evidence based as possible in the holistic, considered and optimal management of IBD in elderly patients. In this review we will cover the clinical features and therapeutic options of IBD in the elderly; as well as addressing common questions and challenges posed by its management.

Fidaxomicin: A novel agent for the treatment of Clostridium difficile infection

Oral vancomycin and oral metronidazole have several limitations with regard to their use in the treatment of Clostridium difficile infections (CDIs); however, oral vancomycin has been considered the gold standard in clinical trials. In June 2012, fidaxomicin received Health Canada approval for the treatment of CDIs. Its chemistry, mechanisms of action and pharmacological properties are discussed, along with its potential role in CDI therapy.

BACKGROUND:

Due to the limitations of existing treatment options for Clostridium difficile infection (CDI), new therapies are needed.

OBJECTIVE:

To review the available data on fidaxomicin regarding chemistry, mechanisms of action and resistance, in vitro activity, pharmacokinetic and pharmacodynamic properties, efficacy and safety in clinical trials, and place in therapy.

METHODS:

A search of PubMed using the terms “fidaxomicin”, “OPT-80”, “PAR-101”, “OP-1118”, “difimicin”, “tiacumicin” and “lipiarmycin” was performed. All English-language articles from January 1983 to November 2014 were reviewed, as well as bibliographies of all articles.

RESULTS:

Fidaxomicin is the first macrocyclic lactone antibiotic with activity versus C difficile. It inhibits RNA polymerase, therefore, preventing transcription. Fidaxomicin (and its active metabolite OP-1118) is bactericidal against C difficile and exhibits a prolonged postantibiotic effect (approximately 10 h). Other than for C difficile, fidaxomicin demonstrated only moderate inhibitory activity against Gram-positive bacteria and was a poor inhibitor of normal colonic flora, including anaerobes and enteric Gram-negative bacilli. After oral administration (200 mg two times per day for 10 days), fidaxomicin achieved low serum concentration levels but high fecal concentration levels (mean approximately 1400 μg/g stool). Phase 3 clinical trials involving adults with CDI demonstrated that 200 mg fidaxomicin twice daily for 10 days was noninferior to 125 mg oral vancomycin four times daily for 10 days in regard to clinical response at the end of therapy. Fidaxomicin was, however, reported to be superior to oral vancomycin in reducing recurrent CDI and achieving a sustained clinical response (assessed at day 28) for patients infected with non-BI/NAP1/027 strains.

CONCLUSION:

Fidaxomicin was noninferior to oral vancomycin with regard to clinical response at the end of CDI therapy. Fidaxomicin has been demonstated to be as safe as oral vancomycin, but superior to vancomycin in achieving a sustained clinical response for CDI in patients infected with non-BI/NAP1/027 strains. Caution should be exercised in using fidaxomicin monotherapy for treatment of severe complicated CDI because limited data are available. Whether fidaxomicin is cost effective (due to its significantly higher acquisition cost versus oral vancomycin) depends on the acceptable willingness to pay threshold per quality-adjusted life year as a measure of assessing cost effectiveness.

Fecal microbiota transplantation for the treatment of Clostridium difficile infection

Clostridium difficile, a major cause of healthcare-associated diarrhea due to perturbation of the normal gastrointestinal microbiome, is responsible for significant morbidity, mortality, and healthcare expenditures. The incidence and severity of C difficile infection (CDI) is increasing, and recurrent disease is common. Recurrent infection can be difficult to manage with conventional antibiotic therapy. Fecal microbiota transplantation (FMT), which involves instillation of stool from a healthy donor into the gastrointestinal tract of the patient, restores the gut microbiome to a healthy state. FMT has emerged as a promising new treatment for CDI. There are limited data on FMT for treatment of primary CDI, but FMT appears safe and effective for recurrent CDI. The safety and efficacy of FMT in patients with severe primary or severe recurrent CDI has not been established. Patients with inflammatory bowel disease (IBD) who undergo FMT for CDI may be at increased risk of IBD flare, and caution should be exercised with use of FMT in that population. The long-term safety of FMT is unknown; thus, rigorously conducted prospective studies are needed.

Clinical and Healthcare Burden of Multiple Recurrences of Clostridium difficile Infection

BACKGROUND

Clostridium difficile infection (CDI) is associated with a high risk of recurrence (rCDI). Few studies have focused on multiple recurrences. To evaluate the potential of novel treatments targeting recurrence, we assessed the burden and severity of rCDI.

METHODS

This was a retrospective cohort of adults diagnosed with CDI in a hospital in Sherbrooke, Canada (1998-2013). An rCDI episode was defined by the reappearance of diarrhea leading to a treatment, with or without a positive toxin assay, within 14-60 days after the previous episode.

RESULTS

We included 1527 patients. The probability of developing a first rCDI was 25% (354/1418); a second, 38% (128/334); a third, 29% (35/121); and a fourth or more, 27% (9/33). Two or more rCDIs were observed in 9% (128/1389) of patients. The risk of a first recurrence fluctuated over time, but there was no such variation for second or further recurrences. The proportion of severe cases decreased (47% for initial episodes, 31% for first recurrences, 25% for second, 17% for third), as did the risk of complicated CDI (5.8% to 2.8%). The severity and risk of complications of first recurrences decreased over time, while oral vancomycin was used more systemically. A hospital admission was needed for 34% (148/434) of recurrences.

CONCLUSIONS

This study documented the clinical and healthcare burden of rCDI: 34% of patients with rCDI needed admission, 28% developed severe CDI, and 4% developed a complication. Secular changes in the severity of recurrences could reflect variations in the predominant strain, or better management.

Recurrent Clostridium difficile infection: From colonization to cure

Clostridium difficile infection (CDI) is increasingly prevalent, dangerous and challenging to prevent and manage. Despite intense national and international attention the incidence of primary and of recurrent CDI (PCDI and RCDI, respectively) have risen rapidly throughout the past decade. Of major concern is the increase in cases of RCDI resulting in substantial morbidity, morality and economic burden. RCDI management remains challenging as there is no uniformly effective therapy, no firm consensus on optimal treatment, and reliable data regarding RCDI-specific treatment options is scant. Novel therapeutic strategies are critically needed to rapidly, accurately, and effectively identify and treat patients with, or at-risk for, RCDI. In this review we consider the factors implicated in the epidemiology, pathogenesis and clinical presentation of RCDI, evaluate current management options for RCDI and explore novel and emerging therapies.

Risk Factors, Clinical Characteristics, and Treatment Differences Between Residents With and Without Nursing Home- and Non-Nursing Home-Acquired Clostridium difficile Infection

BACKGROUND

The incidence of Clostridium difficile infection (CDI) in nursing home residents is believed to be high because of the prevalence of predisposing factors such as decreased immune response, multiple comorbidities, medications, increased risk of infection, close proximity of residents, and recent hospitalization. Yet, specific information on CDI in this population is scarce. 

OBJECTIVES

To investigate differences in clinical and demographic characteristics, treatment, and underlying comorbidities in residents who acquired CDI preadmission (non-nursing home-acquired [NNH-Acquired]) compared with those who acquired CDI after admission to a nursing home (nursing home-acquired [NH-Acquired]) and matched controls.

METHODS

We conducted a retrospective case-control study of CDI in nursing home residents with a cross-sectional and longitudinal aspect of linked and de-identified pharmacy claims and Minimum Data Set data (MDS) 2.0 records from October 1, 2009, to September 30, 2010. The control group was frequency matched 1:1 for gender, race, and age range to residents with CDI. 

RESULTS

Of 195,498 residents, 5,044 (2.6%) had a diagnosis of CDI. Compared with controls, CDI patients had less severe cognitive impairment (P  less than  0.01) and more severe functional impairment (P  less than  0.01), incontinence (P  less than  0.01), and diarrhea (P  less than  0.01). They were more likely to (a) have diabetes, stroke, heart failure, cancer, renal failure, and infections; (b) be treated with antibiotics, corticosteroids, megestrol, and proton pump inhibitors; and (c) be discharged to the hospital (29.3% vs. 14.7%, P = 0.001) than controls. NNH-Acquired CDI was 3 times more prevalent than NH-Acquired CDI. Most residents with NNH-Acquired CDI (85.0%) came from acute care hospitals and were more likely to have heart disease, cancer, and infections, while those with NH-Acquired CDI tended to have more cognitive impairment, reliance on staff for activities of daily living, incontinence, and stroke. Thirty-day retreatment rates for NH-Acquired CDI and NNH-Acquired CDI with metronidazole were 72.7% and 68.4%, and with vancomycin were 83.9% and 69.3%, respectively. The facility (Medicare Part A) was the payer for 93.6% of NNH-Acquired CDI and 75% of NH-Acquired CDI treatment; Medicare Part D was the prevalent secondary payer for NNH-Aquired CDI (19.4%) and NH-Acquired CDI (37.5%).

CONCLUSIONS

Residents with CDI had more comorbidities, and the NNH-Acquired group bore a higher burden of illness, resulting in differing treatment patterns and outcomes than the NH-Acquired CDI group.