Modeling inpatient and outpatient antibiotic stewardship interventions to reduce the burden of Clostridioides difficile infection in a regional healthcare network

Antibiotic exposure can lead to unintended outcomes, including drug-drug interactions, adverse drug events, and healthcare-associated infections like Clostridioides difficile infection (CDI). Improving antibiotic use is critical to reduce an individual's CDI risk. Antibiotic stewardship initiatives can reduce inappropriate antibiotic prescribing (e.g., unnecessary antibiotic prescribing, inappropriate antibiotic selection), impacting both hospital (healthcare)-onset (HO)-CDI and community-associated (CA)-CDI. Previous computational and mathematical modeling studies have demonstrated a reduction in CDI incidence associated with antibiotic stewardship initiatives in hospital settings. Although the impact of antibiotic stewardship initiatives in long-term care facilities (LTCFs), including nursing homes, and in outpatient settings have been documented, the effects of specific interventions on CDI incidence are not well understood. We examined the relative effectiveness of antibiotic stewardship interventions on CDI incidence using a geospatially explicit agent-based model of a regional healthcare network in North Carolina. We simulated reductions in unnecessary antibiotic prescribing and inappropriate antibiotic selection with intervention scenarios at individual and network healthcare facilities, including short-term acute care hospitals (STACHs), nursing homes, and outpatient locations. Modeled antibiotic prescription rates were calculated using patient-level data on antibiotic length of therapy for the 10 modeled network STACHs. By simulating a 30% reduction in antibiotics prescribed across all inpatient and outpatient locations, we found the greatest reductions on network CDI incidence among tested scenarios, namely a 17% decrease in HO-CDI incidence and 7% decrease in CA-CDI. Among intervention scenarios of reducing inappropriate antibiotic selection, we found a greater impact on network CDI incidence when modeling this reduction in nursing homes alone compared to the same intervention in STACHs alone. These results support the potential importance of LTCF and outpatient antibiotic stewardship efforts on network CDI burden and add to the evidence that a coordinated approach to antibiotic stewardship across multiple facilities, including inpatient and outpatient settings, within a regional healthcare network could be an effective strategy to reduce network CDI burden.

Is there a higher prevalence of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) colonization in patients with antibiotic allergy labels?

BACKGROUND

A penicillin allergy label has been associated with significantly higher rates of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) colonization, and correspondingly poorer clinical outcomes. However, there are limited data examining the association between any antibiotic label and colonization rates. We sought to evaluate if there is a relationship between patients with an antibiotic allergy label and prevalence of MRSA or VRE colonization.

METHODS

We retrospectively reviewed all patients with an MRSA surveillance culture between December 15, 2014 and January 31, 2015, or a VRE surveillance culture between January 1, 2013 and January 31, 2015, at a tertiary community-based teaching hospital. Our primary objective was to evaluate the prevalence of MRSA or VRE colonization among patients with and without antibiotic allergies. Bivariate analyses included the χ² test and the Student t test to determine statistical significance for categorical and continuous variables, respectively.

RESULTS

We included a total of 1,053 unique patients screened for MRSA, and 290 unique patients screened for VRE. The rate of MRSA and VRE colonization was 5.8% (62 of 1,053) and 32.4% (94 of 290), respectively, in our cohort. Antibiotic allergies were documented in approximately 1 out of 3 patients, 337 (32%) for the MRSA group and 94 (32%) for VRE group. There was a significant difference in MRSA colonization between patients with and without an antibiotic allergy, 28 of 337 (8.3%) versus 34 of 716 (4.7%) (P = .025), respectively. In contrast, there was no significant difference in antibiotic allergy rates with and without VRE colonization, 34 of 94 (36.2%) versus 92 of 196 (46.9%) (P = .10), respectively.

CONCLUSIONS

An antibiotic allergy label was associated with significantly higher rates of MRSA colonization but no statistical difference with VRE colonization.

Creation of a Geospatially Explicit, Agent-based Model of a Regional Healthcare Network with Application to Clostridioides difficile Infection

Agent-based models (ABMs) describe and simulate complex systems comprising unique agents, or individuals, while accounting for geospatial and temporal variability among dynamic processes. ABMs are increasingly used to study healthcare-associated infections (ie, infections acquired during admission to a healthcare facility), including Clostridioides difficile infection, currently the most common healthcare-associated infection in the United States. The overall burden and transmission dynamics of healthcare-associated infections, including C difficile infection, may be influenced by community sources and movement of people among healthcare facilities and communities. These complex dynamics warrant geospatially explicit ABMs that extend beyond single healthcare facilities to include entire systems (eg, hospitals, nursing homes and extended care facilities, the community). The agents in ABMs can be built on a synthetic population, a model-generated representation of the actual population with associated spatial (eg, home residence), temporal (eg, change in location over time), and nonspatial (eg, sociodemographic features) attributes. We describe our methods to create a geospatially explicit ABM of a major regional healthcare network using a synthetic population as microdata input. We illustrate agent movement in the healthcare network and the community, informed by patient-level medical records, aggregate hospital discharge data, healthcare facility licensing data, and published literature. We apply the ABM output to visualize agent movement in the healthcare network and the community served by the network. We provide an application example of the ABM to C difficile infection using a natural history submodel. We discuss the ABM's potential to detect network areas where disease risk is high; simulate and evaluate interventions to protect public health; adapt to other geographic locations and healthcare-associated infections, including emerging pathogens; and meaningfully translate results to public health practitioners, healthcare providers, and policymakers.

Treatment of Helicobacter pylori Is Not Associated With Future Clostridium difficile Infection

INTRODUCTION

Helicobacter pylori (HP) infection is associated with many gastrointestinal disorders, including gastric cancer, and consensus guidelines recommend eradication after detection. There is a theoretical, yet uninvestigated, concern that HP treatment could increase the risk of Clostridium difficile infection (CDI). Using the data from a large cohort of patients with HP, we investigated whether HP eradication is associated with CDI.

METHODS

A retrospective cohort study within the Veterans Health Administration on 38,535 patients (median age 61.8 years; 91.8% men) with detected HP between January 1, 1994, and December 31, 2018 was conducted. Primary outcome was a positive laboratory test for CDI within 3 months of HP detection. Multivariable logistic regression evaluated the following: patient demographics, previous CDI, recent hospitalization, and whether the patient received HP eradication therapy (by antibiotic and regimen, and including proton pump therapy). Secondary analysis of those treated evaluated whether eradication of HP was associated with CDI.

RESULTS

Among 38,535 patients, 28,818 (74.8%) were treated for HP and 284 (0.74%) developed CDI. In multivariable analysis, prominent factors included hospital discharge within 12 weeks (odds ratio [OR] 2.15; 95% confidence interval [CI]: 1.22-3.77) and 4 weeks (OR 3.46; 95% CI: 2.18-5.48), P < 0.001, and previous CDI (OR 12.5; 95% CI: 9.21-17.0, P < 0.001). Treatment of HP was not associated with future CDI. In secondary analysis of those treated, confirmation of eradication was not associated with future CDI (OR 1.49; 95% CI: 0.67-3.29).

DISCUSSION

In a large study of US patients with HP, we demonstrate that neither treatment nor eradication of HP is associated with CDI. Previous C. difficile infection and recent hospital discharge, established risk factors for CDI, are strongly associated. These findings suggest that treatment should be continued to be prescribed when HP is detected (http://links.lww.com/AJG/B507).

Antibiotic Exposure and Risk for Hospital-Associated Clostridioides difficile Infection

Clostridioides difficile infection (CDI) is a health care-associated infection associated with significant morbidity and cost, with highly varied risk across populations. More effective, risk-based prevention strategies are needed. Here, we investigate risk factors for hospital-associated CDI in a large integrated health system. In a retrospective cohort of all adult admissions to 21 Intermountain Healthcare hospitals from 2006 to 2012, we identified all symptomatic (i) hospital-onset and (ii) health care-facility-associated, community-onset CDI. We then evaluated the risk associated with antibiotic exposure, including that of specific agents, using multivariable logistic regression. A total of 2,356 cases of CDI among 506,068 admissions were identified (incidence, 46.6 per 10,000). Prior antibiotic use was the dominant risk factor, where for every antibiotic day of therapy prior to the index admission, the odds of subsequent CDI increased by 12.8% (95% confidence interval [CI], 12.2 to 13.4%; P < 0.0001). This was a much stronger association than was inpatient antibiotic exposure (odds ratio [OR], 1.007 [95% CI, 1.005 to 1.009]; P < 0.0001). The highest-risk antibiotics included second-generation and later cephalosporins (especially oral), carbapenems, fluoroquinolones, and clindamycin, while doxycycline and daptomycin were associated with a lower CDI risk. We concluded that cumulative antibiotic exposure prior to admission is the greatest contributor to the risk of subsequent CDI. Most classes of antibiotics carry some risk, which varies by drug and route. This information may be useful for antimicrobial stewardship efforts.

Screening of Clostridioides difficile carriers in an urban academic medical center: Understanding implications of disease

OBJECTIVE

Efforts to reduce Clostridioides difficile infection (CDI) have targeted transmission from patients with symptomatic C. difficile. However, many patients with the C. difficile organism are carriers without symptoms who may serve as reservoirs for spread of infection and may be at risk for progression to symptomatic C. difficile. To estimate the prevalence of C. difficile carriage and determine the risk and speed of progression to symptomatic C. difficile among carriers, we established a pilot screening program in a large urban hospital.

DESIGN

Prospective cohort study.

SETTING

An 800-bed, tertiary-care, academic medical center in the Bronx, New York.

PARTICIPANTS

A sample of admitted adults without diarrhea, with oversampling of nursing facility patients.

METHODS

Perirectal swabs were tested by polymerase chain reaction for C. difficile within 24 hours of admission, and patients were followed for progression to symptomatic C. difficile. Development of symptomatic C. difficile was compared among C. difficile carriers and noncarriers using a Cox proportional hazards model.

RESULTS

Of the 220 subjects, 21 (9.6%) were C. difficile carriers, including 10.2% of the nursing facility residents and 7.7% of the community residents (P = .60). Among the 21 C. difficile carriers, 8 (38.1%) progressed to symptomatic C. difficile, but only 4 (2.0%) of the 199 noncarriers progressed to symptomatic C. difficile (hazard ratio, 23.9; 95% CI, 7.2-79.6; P < .0001).

CONCLUSIONS

Asymptomatic carriage of C. difficile is prevalent among admitted patients and confers a significant risk of progression to symptomatic CDI. Screening for asymptomatic carriers may represent an opportunity to reduce CDI.

Clostridioides difficile incidence related to in-hospital cephalosporin use: a tale of two highly comparable hospitals

Background

Antibiotic treatment is a well-known risk factor for healthcare facility-associated Clostridioides (Clostridium) difficile infection (HCF-CDI). Antibiotic stewardship programmes (ASPs) targeting high-risk antibiotics have been shown to decrease HCF-CDI incidence. HCF-CDI incidence is high in Nordic countries despite relatively low antibiotic use in hospital.

Objectives

To determine if HCF-CDI incidence was modified by a hospital ASP that restricted cephalosporin use.

Methods

The effects of an ASP on HCF-CDI incidence were evaluated in a two-centre setting using a retrospective design. We exploited a strategy of both individual case ascertainment based on chart reviews and aggregated data from the hospitals. Cases were attributed to the antibiotics given prior to disease onset, in proportion to the number of DDDs used. Three periods were studied: 2007 (before the ASP), 2012 and 2015.

Results

At the ASP hospital, cephalosporin use decreased by 87% and the number of HCF-CDI/1000 hospital admissions decreased significantly from 2.25 (2007) to 1.16 (2015) (P = 0.0014). The corresponding results at the non-ASP hospital showed a non-significant increase from 2.09 to 2.38. A high number of cases could be attributed to cephalosporins at both hospitals. The increased use of other broad-spectrum antibiotics, e.g. piperacillin/tazobactam, at the ASP hospital was not associated with offsetting increases in attributable HCF-CDI cases.

Conclusions

Decreased use of cephalosporins is an effective strategy to decrease HCF-CDI incidence over time in a setting with high incidence and low antibiotic use.

Zinc Level and Its Role in Recurrent Clostridium difficile Infection: A Case Report and Literature Review

Clostridium difficile infection is a common nosocomial infection in US hospitals, accounting for approximately 12 800 deaths annually in the United States. These infections are often associated with the use of antibiotics, which can alter the gut microbiome and thus render patients susceptible to C difficile infection. C difficile is often spread via fecal oral transmission. Multiple medications have been developed, but recurrence rates reach 60% after treatment. Recent data have shown that zinc supplementation decreases the recurrence of C difficile infection. In this article, we present a case of recurrent C difficile infection with zinc deficiency in which zinc supplementation improved the symptoms and reduced the incidence of recurrence.

Evaluation of anti-infective-related Clostridium difficile-associated colitis using the Japanese Adverse Drug Event Report database

Clostridium difficile-associated colitis (CDAC) may cause gastrointestinal illness, ranging in severity from mild diarrhea to fulminant colitis and even mortality. The purpose of this study was to evaluate anti-infective-related CDAC profiles using the Japanese Adverse Drug Event Report (JADER) database. Methods: We selected case reports of adverse events of CDAC as specified in the Medical Dictionary for Regulatory Activities. The association between the number of administered anti-infectives and aging was evaluated using reporting odds ratio (ROR) and adjusted for covariates using multiple-logistic regression. We also evaluated anti-infective-related CDAC-onset profiles using Weibull shape parameter. Results: The JADER database contained 534 688 reports from April 2004 to June 2018. There were 1222 anti-infective related CDAC events. The top five anti-infectives were as follows: third-generation cephalosporins (Anatomical Therapeutic Chemical (ATC) code: J01DD, 313 cases), fluoroquinolones (ATC code: J01MA, 201 cases), macrolides (ATC code: J01FA, 146 cases), carbapenems (ATC code: J01DH, 143 cases), and penicillins with extended spectrum (ATC code: J01CA, 103 cases). The adjusted RORs (95% confidence interval) in individuals using 1, 2, and ≥ 3 anti-infectives were 8.88 (7.05-11.18), 9.77 (6.89-13.86), and 18.39 (11.85-28.54), respectively. Moreover, 47.2% of CDACs occurred within 7 days of anti-infective therapy initiation. The adjusted ROR of interaction terms of ≥ 70 years × 1 drug was 21.81 (14.56-32.68). Conclusion: Our results suggest that the number of administered anti-infectives and patient age are associated with CDAC. These data may be particularly beneficial to prescribers and would contribute to improving the management of CDAC.

Epidemiology and virulence-associated genes of Clostridioides difficile isolates and factors associated with toxin EIA results at a university hospital in Japan

Introduction

Clostridioides difficile is one of the most important nosocomial pathogens; however, reports regarding its clinical and molecular characteristics from Japan are scarce.

Aims

We studied the multilocus sequence typing (MLST)-based epidemiology and virulence-associated genes of isolates and the clinical backgrounds of patients from whom the isolates had been recovered.

Methods

A total of 105 stool samples tested in a C. difficile toxin enzyme immune assay (EIA) were analysed at the University of Tokyo Hospital from March 2013 to July 2014. PCR for MLST and the virulence-associated genes tcdA, tcdB, cdtA, cdtB and tcdC was performed on C. difficile isolates meeting our inclusion criteria following retrospective review of medical records. EIA-positive and EIA-negative groups with toxigenic strains underwent clinical and molecular background comparison.

Results

The toxigenic strains ST17, ST81, ST2, ST54, ST8, ST3, ST37 and ST53 and the non-toxigenic strains ST109, ST15 and ST100 were frequently recovered. The prevalence rate of tcdA-negative ST81 and ST37, endemic in China and Korea, was higher (11.4%) than that reported in North America and Europe, and hypervirulent ST1(RT027) and ST11(RT078) strains that occur in North America and Europe were not recovered. The linkage between the EIA results and cdt A/B positivity, tcdC deletion, or tcdA variation was absent among toxigenic strains. Compared with the 38 EIA-negative cases, the 36 EIA-positive cases showed that the patients in EIA-positive cases were older and more frequently had chronic kidney disease, as well as a history of beta-lactam use and proton pump inhibitor therapy.

Conclusion

In Japan, the prevalence rates for tcdA-negative strains are high, whereas the cdtA/B-positive strains are rare. EIA positivity is linked to older age, chronic kidney disease and the use of beta-lactams and proton pump inhibitors.

Effects of proton pump inhibitor use on risk of Clostridium difficile infection: a hospital cohort study

BACKGROUND

Although there are several studies on the association between use of proton pump inhibitors (PPIs) and increased Clostridium difficile infection (CDI) risk, detailed studies analyzing the effects of PPI use on CDI risk are lacking. The present study investigated the association of the dose, duration, and types of PPIs with CDI risk.

METHODS

A single-center, cohort study was conducted on patients admitted to a hospital. The exposed cohort comprised patients who were prescribed PPIs at least once during the study period, and a control cohort was prepared by randomly assigning an index date to patients who did not use PPIs ensuring the same distribution of index dates as in the exposed cohort and matching sex, age, hospitalization period, and date of admission.

RESULTS

PPI use increased the risk of CDI by 1.8-fold [95% confidence interval (CI) 1.5-2.2]. CDI risk increased by 1.8-fold with esomeprazole (95% CI 1.4-2.2) and 2.0-fold with pantoprazole (95% CI 1.5-2.8). Patients who used a high dose had a higher risk than those who used a medium dose [adjusted hazard ratio (HR) 2.0 vs 1.3]. The risk of CDI increased 4.2-fold when the PPI exposure period was 6 days or shorter than 6 days.

CONCLUSIONS

Our study showed that PPI use was associated with an increased risk of developing CDI and the risk of CDI was dose dependent. Therefore, PPIs should only be used at proper doses and only for the necessary indications to avoid CDI risk.

Parvimonas micra spondylodiscitis with psoas abscess

Parvimonas micra (P. micra) is a Gram-positive anaerobic cocci, normally found in the oral cavity and rarely causes severe infections. We describe a rare clinical presentation of P. micra as spondylodiscitis and psoas abscess with haematogenous spread in an adult patient. MRI lumbar spine detected L2 and L3 spondylodiscitis. Blood cultures were positive at 48 hours of incubation and P. micra was identified on anaerobic culture after 72 hours. Isolates from bone biopsy confirms P. micra She was successfully treated with ceftriaxone, followed by oral metronidzole for a total of 8 weeks. The suspected origin of her P. micra was a dental cavity. Anaerobic bacteria tend to be underestimated in spondylodiscitis. In cases of slow growing organisms, we emphasise the importance of performing accurate identification including anaerobic bacteria to guide management. P. micra should be considered in patients with spondylodiscitis who had recent dental intervention or perioral infection.

Clostridioides difficile Enteritis in Patients Following Total Colectomy-a Rare but Genuine Clinical Entity

Objective

Clostridioides difficile infection (CDI) frequently causes colitis following antibiotic exposure and is a leading cause of gastrointestinal infectious mortality. Infection in the small bowel, C. difficile enteritis (CDE), was previously thought impossible, but case series have challenged this dogma. Clostridioides difficile enteritis prevalence, severity, and potential risk factors are unknown.

Methods

We retrospectively analyzed all total colectomy patients over a 20-year period at our institution. C. difficile enteritis was defined by clinical symptoms and positive C. difficile stool testing after colectomy. We compared CDE cases to controls using multivariable analysis to identify potential CDE risk factors.

Results

C. difficile enteritis occurred in 44 of 855 (5.1%) patients, a median of 130 days after colectomy. Compared to controls, CDE patients were similar in age, gender, and presence of immunosuppression. The majority (64%) had antibiotics <30 days prior to CDE. In multivariable analysis, CDE risk factors included perioperative acid suppression (hazard ratio [HR], 2.52; 95% confidence interval [CI], 1.26–5.04; P = .009), colectomy for inflammatory bowel disease (HR, 2.95; CI, 1.29–6.72; P = .010), colectomy for CDI (HR, 9.95; CI, 2.70–36.63; P ≤ .001), and β-lactam use in the setting of enteral feeds (HR, 17.83; CI, 2.75–115.68; P = .003). C. difficile enteritis presented with severe disease half of the time, with 81.8% requiring hospitalization.

Conclusions

C. difficile enteritis is a rare clinical entity that should be considered in postcolectomy patients presenting with CDI symptoms, even years after surgery. Like traditional CDI, likely CDE risk factors include acid suppression and inflammatory bowel disease. Prior antibiotic use in the setting of enteral feeds may amplify CDE risk. C. difficile enteritis often presents as severe disease and frequently requires hospitalization.

Direct antimicrobial susceptibility testing from positive blood culture bottles in laboratories lacking automated antimicrobial susceptibility testing systems

BACKGROUND

Timely initiation of appropriate antimicrobial can improve the outcome in terms of reduced morbidity and mortality in addition to reduced health-care costs. Availability of early preliminary Antimicrobial Susceptibility Test (AST) report will be useful in directing antimicrobial therapy. The aim of the study was to correlate AST by disc diffusion method, directly from positively flagged blood culture bottles, with the AST by automated method.

METHODS

A total of 144 aerobic blood culture bottles flagged positive by the automated blood culture system were processed. The bacteria were pelleted by two-step centrifugation of the broth from the bottle and used to make a smear for Gram stain as well as an inoculum for antimicrobial sensitivity testing by Kirby Bauer disc diffusion method. Automated identification and AST were also carried out.

RESULTS

On direct staining, 94 samples showed gram-negative bacilli, 39 showed gram-positive cocci, and 11 showed yeasts or polymicrobial growth. In the case of gram-negative bacteria, there was 99% categorical agreement between direct sensitivity testing and automated sensitivity testing with 1% disagreement. Among the gram-positive cocci, there was 96% categorical agreement with 4% disagreement between the two methods.

CONCLUSION

High degree of agreement between the two methods is promising and applicable to situations where automated sensitivity testing is not available. Even if the systems are available, this method would prove useful as an adjunct to standard AST reporting. This sensitivity report can be generated earlier than the conventional AST, enabling choice of appropriate antimicrobial.

Cost and Risk Analysis of Lifelong Penicillin Allergy

Patients labeled as being penicillin-allergic require the use of alternative antibiotics. The objective of this study was to estimate the lifetime antibiotic costs of patients labeled as being penicillin allergic prior to age 10 compared with those who were not penicillin allergic and to compare antibiotic utilization between these 2 groups with regard to risks of adverse effects. Using the low end of the antibiotic cost range, penicillin-allergic patients had a mean lifetime antibiotic cost of $8171 per patient, compared with $6278 for non-penicillin-allergic patients, a difference of $1893. Penicillin-allergic patients utilized more moderate-spectrum antibiotics, more fluoroquinolones, and had a higher estimated Clostridium difficile risk.

Management of Clostridioides (formerly Clostridium) difficile infection (CDI) in solid organ transplant recipients: Guidelines from the American Society of Transplantation Community of Practice

These updated guidelines from the American Society of Transplantation Infectious Diseases Community of Practice address the prevention and management of Clostridium difficile infection in solid organ transplant (SOT) recipients. Clostridioides (formerly Clostridium) difficile infection (CDI) is among the most common hospital acquired infections. In SOT recipients, the incidence of CDI varies by type and number or organs transplanted. While a meta-analysis of published literature found the prevalence of postoperative CDI in the general surgical population to be approximately 0.51%, the prevalence of CDI that is seen in the solid organ transplant population ranges from a low of 3.2% in the pancreatic transplant population to 12.7% in those receiving multiple organ transplants. There are no randomized, controlled trials evaluating the management of CDI in the SOT population. Herein is a review and summary of the currently available literature that has been synthesized into updated treatment guidelines for the management of CDI in the SOT population.

The morbidity of C. difficile in necrotizing pancreatitis

INTRODUCTION

Necrotizing pancreatitis (NP) patients commonly require antibiotic treatment during the several month-long disease course. We hypothesized that Clostridium difficile infection (CDI) is common in NP and significantly impacts outcomes.

MATERIALS AND METHODS

Retrospective review of 704 NP patients treated at a single-institution (2005-2018).

RESULTS

10% (67/704) of patients developed CDI a mean 78 days after NP onset. Patients developing CDI experienced increased total hospital days (CDI, 104; No CDI, 42; P < 0.001), readmission rates (CDI, 85%; No CDI, 64%; P = 0.006), and duration of NP (CDI, 248 days; No CDI, 183; P = 0.001). Risk factors for CDI included antibiotic use (OR, 96.2; 95% CI, 5.9-1556.2; P = 0.001) and any organ failure (OR, 2.0; 95% CI, 1.2-3.3, P = 0.008). Mortality was not affected by CDI (CDI, 10%; No CDI, 9%; P = 0.7).

CONCLUSION

Clostridium difficile infection is common in necrotizing pancreatitis and negatively impacts morbidity and disease recovery.

Epidemiology of Clostridioides difficile infections, France, 2010 to 2017

BackgroundClostridioides difficile is a leading cause of healthcare-associated diarrhoea in middle and high-income countries. Up to 2018, there has been no systematic, annual surveillance for C. difficile infections (CDI) in France.AimsTo provide an updated overview of the epidemiology of CDI in France between 2010 and 2017 based on five different data sources.MethodsThis is a descriptive study of retrospective surveillance and alerts data. Incidence of CDI cases was estimated through the CDI incidence survey (2016) and data from the French National Uniform Hospital Discharge Database (PMSI; 2010-16). Testing frequency for CDI was estimated through the CDI incidence survey and point prevalence studies on healthcare-associated infections (HAI; 2012 and 2017). The national early warning response system for HAI (HAI-EWRS, 2012-17) and National Reference Laboratory data (2012-17) were used to follow the number of severe CDI cases and/or outbreaks.ResultsIn 2016, CDI incidence in acute care was 3.6 cases per 10,000 patient days (PD). There was a statistically significant increase in CDI incidence between 2010 and 2016 (+ 14% annually) and testing frequency was 47.4 per 10,000 PD. The number of CDI HAI-EWRS notifications decreased between 2015 and 2017 with only a few large outbreaks reported.ConclusionThe CDI incidence estimate increased from 2010, but remained below the European average of 7 per 10,000 PD in 2014; there were fewer severe cases or clusters reported in France. The consistency between PMSI and laboratory-based estimated CDI incidence could allow for more routine monitoring of CDI incidence.

Prolonged antimicrobial prophylaxis following cardiac device procedures increases preventable harm: insights from the VA CART program

BACKGROUND

The rate of cardiovascular implantable electronic device (CIED) infection is increasing coincident with an increase in the number of device procedures. Preprocedural antimicrobial prophylaxis reduces CIED infections; however, there is no evidence that prolonged postprocedural antimicrobials additionally reduce risk. Thus, we sought to quantify the harms associated with this approach.

OBJECTIVE

To measure the association between Clostridium difficile infection (CDI), acute kidney injury (AKI) and receipt of prolonged postprocedural antimicrobials.

METHODS

CIED procedures entered into the VA Clinical Assessment Reporting and Tracking Electrophysiology (CART-EP) database during fiscal years 2008-2016 were included. The primary outcome was 90-day incidence of CDI and the secondary outcome was the 7-day incidence of AKI. The primary exposure measure was duration of postprocedural antimicrobial therapy. Associations were measured using Cox-proportional hazards and binomial regression.

RESULTS

Prolonged postprocedural antimicrobial therapy was identified following 3,331 of 6,497 CIED procedures (51.3%), and the median duration of prophylaxis was 5 days. Prolonged postprocedural antimicrobial use was associated with increased risk of CDI (hazard ratio [HR], 2.90; 95% confidence interval [CI], 1.54-5.46). Of the 27 patients who developed CDI, 11 subsequently died. Postprocedural antimicrobial use with ≥2 antimicrobials was associated with an increased risk of AKI (OR, 4.16; 95% CI, 2.50-6.90). The impact was particularly significant when one of the dual agents prescribed was vancomycin (adjusted OR, 8.41; 95% CI, 5.53-12.79).

CONCLUSIONS

Prolonged antimicrobial prophylaxis following CIED procedures increases preventable harm; this practice should be discouraged in procedural settings such as the cardiac electrophysiology laboratory.

Residual effect of community antimicrobial exposure on risk of hospital onset healthcare-associated Clostridioides difficile infection: a case-control study using national linked data

BACKGROUND

Associations between antimicrobial exposure in the community and community-associated Clostridioides difficile infection (CA-CDI) are well documented but associations with healthcare-associated CDI (HA-CDI) are less clear. This study estimates the association between antimicrobial prescribing in the community and HA-CDI.

METHODS

A matched case-control study was conducted by linking three national patient level datasets covering CDI cases, community prescriptions and hospitalizations. All validated cases of HA-CDI (August 2010 to July 2013) were extracted and up to three hospital-based controls were matched to each case on the basis of gender, age, hospital and date of admission. Conditional logistic regression was applied to estimate the association between antimicrobial prescribing in the community and HA-CDI. A sensitivity analysis was conducted to consider the impact of unmeasured hospital antimicrobial prescribing.

RESULTS

Nine-hundred and thirty unique cases of HA-CDI with onset in hospital and no hospital discharge in the 12 weeks prior to index admission were linked with 1810 matched controls. Individuals with prior prescription of any antimicrobial in the community had an odds ratio (OR) = 1.41 (95% confidence interval (CI) 1.13-1.75) for HA-CDI compared with those without. Individuals exposed to high-risk antimicrobials (cephalosporins, clindamycin, co-amoxiclav or fluoroquinolones) had an OR = 1.86 (95% CI: 1.33-2.59). After accounting for the likely impact of unmeasured hospital prescribing, the community exposure, particulary to high-risk antimicrobials, was still associated with elevated HA-CDI risk.

CONCLUSIONS

Community antimicrobial exposure is an independent risk factor for HA-CDI and should be considered as part of the risk assessment of patients developing diarrhoea in hospital.

Real-world effectiveness of infection prevention interventions for reducing procedure-related cardiac device infections: Insights from the veterans affairs clinical assessment reporting and tracking program

OBJECTIVE

To measure the association between receipt of specific infection prevention interventions and procedure-related cardiac implantable electronic device (CIED) infections.

DESIGN

Retrospective cohort with manually reviewed infection status.

SETTING

Setting: National, multicenter Veterans Health Administration (VA) cohort.

PARTICIPANTS

Sampling of procedures entered into the VA Clinical Assessment Reporting and Tracking-Electrophysiology (CART-EP) database from fiscal years 2008 through 2015.

METHODS

A sample of procedures entered into the CART-EP database underwent manual review for occurrence of CIED infection and other clinical/procedural variables. The primary outcome was 6-month incidence of CIED infection. Measures of association were calculated using multivariable generalized estimating equations logistic regression.

RESULTS

We identified 101 procedure-related CIED infections among 2,098 procedures (4.8% of reviewed sample). Factors associated with increased odds of infections included (1) wound complications (adjusted odds ratio [aOR], 8.74; 95% confidence interval [CI], 3.16-24.20), (2) revisions including generator changes (aOR, 2.4; 95% CI, 1.59-3.63), (3) an elevated international normalized ratio (INR) &gt;1.5 (aOR, 1.56; 95% CI, 1.12-2.18), and (4) methicillin-resistant Staphylococcus colonization (aOR, 9.56; 95% CI, 1.55-27.77). Clinically effective prevention interventions included preprocedural skin cleaning with chlorhexidine versus other topical agents (aOR, 0.41; 95% CI, 0.22-0.76) and receipt of β-lactam antimicrobial prophylaxis versus vancomycin (aOR, 0.60; 95% CI, 0.37-0.96). The use of mesh pockets and continuation of antimicrobial prophylaxis after skin closure were not associated with reduced infection risk.

CONCLUSIONS

These findings regarding the real-world clinical effectiveness of different prevention strategies can be applied to the development of evidence-based protocols and infection prevention guidelines specific to the electrophysiology laboratory.

Risk factors for community-associated Clostridioides difficile infection in young children

The majority of paediatric Clostridioides difficile infections (CDI) are community-associated (CA), but few data exist regarding associated risk factors. We conducted a case–control study to evaluate CA-CDI risk factors in young children. Participants were enrolled from eight US sites during October 2014–February 2016. Case-patients were defined as children aged 1–5 years with a positive C. difficile specimen collected as an outpatient or ⩽3 days of hospital admission, who had no healthcare facility admission in the prior 12 weeks and no history of CDI. Each case-patient was matched to one control. Caregivers were interviewed regarding relevant exposures. Multivariable conditional logistic regression was performed. Of 68 pairs, 44.1% were female. More case-patients than controls had a comorbidity (33.3% vs. 12.1%; P = 0.01); recent higher-risk outpatient exposures (34.9% vs. 17.7%; P = 0.03); recent antibiotic use (54.4% vs. 19.4%; P < 0.0001); or recent exposure to a household member with diarrhoea (41.3% vs. 21.5%; P = 0.04). In multivariable analysis, antibiotic exposure in the preceding 12 weeks was significantly associated with CA-CDI (adjusted matched odds ratio, 6.25; 95% CI 2.18–17.96). Improved antibiotic prescribing might reduce CA-CDI in this population. Further evaluation of the potential role of outpatient healthcare and household exposures in C. difficile transmission is needed.

A Systematic Review and Meta-analysis of Antibiotic Treatment Duration for Bacteremia Due to Enterobacteriaceae

The duration of antibiotic therapy for bacteremia due to Enterobacteriaceae is not well defined. We sought to evaluate the clinical outcomes with shorter- versus longer-course treatment. We performed a systematic search of the PubMed and EMBASE databases through May 2018. Studies presenting comparative outcomes between patients receiving antibiotic treatment for ≤10 days ("short-course") and those treated for >10 days ("long-course") were considered eligible. Four retrospective cohort studies and one randomized controlled trial comprising 2,865 patients met the inclusion criteria. The short- and long-course antibiotic treatments did not differ in 30-day all-cause mortality (1,374 patients; risk ratio [RR] = 0.99; 95% confidence interval [CI], 0.69 to 1.43), 90-day all-cause mortality (1,750 patients; RR = 1.16; 95% CI, 0.81 to 1.66), clinical cure (1,080 patients; RR = 1.02; 95% CI, 0.96 to 1.08), or relapse at 90 days (1,750 patients; RR = 1.08; 95% CI, 0.69 to 1.67). In patients with bacteremia due to Enterobacteriaceae, the short- and long-course antibiotic treatments did not differ significantly in terms of clinical outcomes. Further well-designed studies are needed before treatment for 10 days or less is adopted in clinical practice.

Clostridium difficile infection: review

Clostridium difficile (C. difficile) is a Gram-positive, spore-forming, anaerobic bacillus, which is widely distributed in the intestinal tract of humans and animals and in the environment. In the last decade, the frequency and severity of C. difficile infection has been increasing worldwide to become one of the most common hospital-acquired infections. Transmission of this pathogen occurs by the fecal-oral route and the most important risk factors include antibiotic therapy, old age, and hospital or nursing home stay. The clinical picture is diverse and ranges from asymptomatic carrier status, through various degrees of diarrhea, to the most severe, life threatening colitis resulting with death. Diagnosis is based on direct detection of C. difficile toxins in feces, most commonly with the use of EIA assay, but no single test is suitable as a stand-alone test confirming CDI. Antibiotics of choice are vancomycin, fidaxomicin, and metronidazole, though metronidazole is considered as inferior. The goal of this review is to update physicians on current scientific knowledge of C. difficile infection, focusing also on fecal microbiota transplantation which is a promising therapy.

Clostridium difficile-associated diarrhea following the therapy with antibiotic and proton pump inhibitors in a 77-year-old man with several comorbidities: A case report

RATIONALE

Clostridium difficile-associated diarrhea (CDAD) remains a persistent challenge, with substantially increased incidence and severity. The rising burden of CDAD requires urgent identification of preventable risk factors.

PATIENTS CONCERNS

A 77-year-old man with the symptoms of abdominal pain and watery diarrhea was readmitted to the hospital, who received cephalosporins and proton pump inhibitors (PPIs) during the initial hospitalization for 12 days until discharge. Antibiotic-associated diarrhea was seriously suspected. And the stool sample was immediately sent for inspection for C difficile. He had a history of chronic bronchitis, coronary heart disease, and osteonecrosis.

DIAGNOSIS

CDAD, renal insufficiency INTERVENTIONS:: Oral vancomycin was administered for 14 days.

OUTCOMES

On the third day after readmission, the stool sample turned out to be positive for both C difficile toxin and its antigen. After 10-day treatment with vancomycin, diarrhea symptoms disappeared and his stools became normal.

LESSONS

In elderly patients with multiple comorbidities, PPIs must be administered cautiously to minimize the risk for adverse effects including CDAD. It is important to identify the preventable risk factors of CDAD for clinicians and pharmacists. Oral vancomycin therapy seems to be effective in CDAD.

2019 update of the WSES guidelines for management of Clostridioides (Clostridium) difficile infection in surgical patients

In the last three decades, Clostridium difficile infection (CDI) has increased in incidence and severity in many countries worldwide. The increase in CDI incidence has been particularly apparent among surgical patients. Therefore, prevention of CDI and optimization of management in the surgical patient are paramount. An international multidisciplinary panel of experts from the World Society of Emergency Surgery (WSES) updated its guidelines for management of CDI in surgical patients according to the most recent available literature. The update includes recent changes introduced in the management of this infection.

Long-Term Efficacy of Oral Vancomycin Prophylaxis for the Prevention of Clostridium difficile Recurrence

BACKGROUND

Limited evidence suggests that prophylactic oral vancomycin may be beneficial in preventing Clostridium difficile infection (CDI) recurrence, but long-term efficacy is unknown.

OBJECTIVE

To evaluate the long-term efficacy of oral vancomycin prophylaxis (OVP) in preventing CDI recurrence in subjects who require subsequent antibiotic exposure.

METHODS

A retrospective cohort study was conducted at a community hospital. A total of 91 subjects with a history of CDI between January 2013 and December 2015 who had a subsequent hospitalization requiring systemic antibiotics within 12 months were evaluated. Thirty-two subjects who received prophylaxis with oral vancomycin were compared to 59 subjects who did not receive prophylaxis.

RESULTS

CDI recurrence within 12 months was significantly lower in subjects receiving OVP compared to those who did not receive OVP (6.3% vs 28.8%; odds ratio [OR]: 0.16; 95% confidence interval [CI]: 0.04-0.77; P = .011) including patients whose previous CDI was an initial episode (3.7% [1/27] vs 28.3% [15/53]; OR: 10.3; 95% CI: 1.28-82.6; P = .009).

CONCLUSION

Use of OVP in subjects with a history of CDI up to 12 months prior to subsequent antibiotic exposure appears to reduce the risk of CDI recurrence for up to 12 months.

Association of Community Factors with Hospital-onset Clostridioides (Clostridium) difficile Infection: A Population Based U.S.-wide Study

BACKGROUND

Clostridioides (Clostridium) difficile ranks first among the pathogens of hospital-acquired infections with hospital-based preventive strategies being only partially successful in containing its spread.

METHODS

We performed a spatial statistical analysis to examine the association between population characteristics and parameters of community healthcare practice and delivery with hospital-onset Clostridioides (Clostridium) difficile infection (HO-CDI), using data from the Medicare Hospital Compare, Medicare Provider Utilization Part D, and other databases. Among the areas with the highest HO-CDI rates ("hot spots"), we conducted a geographically weighted regression (GWR) to quantify the effect of the decrease in the modifiable risk factors on the HO-CDI rate.

FINDINGS

Percentage of population > 85 years old, community claims of antimicrobial agents and acid suppressants, and density of hospitals and nursing homes within the hospital service areas (HSAs) had a statistically significant association with the HO-CDI incidence (p < 0.001). The model including the community claims of antimicrobial agents and number of hospital centers per HSA km² was associated with 10% (R² = 0.10, p < 0.001) of the observed variation in HO-CDI rate. The hot spots were organized into 5 Combined Statistical areas that crossed state borders. The association of the antimicrobial claims and HO-CDI rate was as high as 71% in the Boston-Worcester-Providence area (R² = 0.71, SD 0.19), with a 10% decrease in the rate of antimicrobial claims having the potential to lead to up to 23.1% decrease in the HO-CDI incidence in this area.

INTERPRETATION

These results outline the association of HO-CDI with community practice and characteristics of the healthcare delivery system and support the need to further study the effect of community and nursing home-based antimicrobial and acid suppressant stewardship programs in the rate of HO-CDI in geographic areas that may cross state lines.

Genome Location Dictates the Transcriptional Response to PolC Inhibition in Clostridium difficile

Clostridium difficile is a potentially lethal gut pathogen that causes nosocomial and community-acquired infections. Limited treatment options and reports of reduced susceptibility to current treatment emphasize the necessity for novel antimicrobials. The DNA polymerase of Gram-positive organisms is an attractive target for the development of antimicrobials. ACX-362E [N ²-(3,4-dichlorobenzyl)-7-(2-[1-morpholinyl]ethyl)guanine; MorE-DCBG] is a DNA polymerase inhibitor in preclinical development as a novel therapeutic against C. difficile infection. This synthetic purine shows preferential activity against C. difficile PolC over those of other organisms in vitro and is effective in an animal model of C. difficile infection. In this study, we have determined its efficacy against a large collection of clinical isolates. At concentrations below the MIC, the presumed slowing (or stalling) of replication forks due to ACX-362E leads to a growth defect. We have determined the transcriptional response of C. difficile to replication inhibition and observed an overrepresentation of upregulated genes near the origin of replication in the presence of PolC inhibitors, but not when cells were subjected to subinhibitory concentrations of other antibiotics. This phenomenon can be explained by a gene dosage shift, as we observed a concomitant increase in the ratio between origin-proximal and terminus-proximal gene copy number upon exposure to PolC inhibitors. Moreover, we show that certain genes differentially regulated under PolC inhibition are controlled by the origin-proximal general stress response regulator sigma factor B. Together, these data suggest that genome location both directly and indirectly determines the transcriptional response to replication inhibition in C. difficile.

Retrospective analysis of Clostridium difficile infection in patients with ulcerative colitis in a tertiary hospital in China

BACKGROUND

Many reports have documented the increasing impact of Clostridium difficile infection (CDI) in patients with ulcerative colitis (UC). We conducted a retrospective study to determine the incidence, clinical characteristics, risk factors and prognosis of CDI in patients with UC.

METHODS

We studied patients with UC, hospitalized between January 2010 and December 2015 in a tertiary hospital in China. Stool samples were tested for C. difficile toxins A and B (CDAB) by enzyme immunoassays in UC patients with disease flare. CDI in UC patients was diagnosed by clinical symptoms and positive CDAB test, and each case was matched with CDAB-negative patients in a 1:2 ratio. Univariate and binary logistic regression analyses were used to measure the differences between patients with and without CDI.

RESULTS

Thirty-four (8.92%) of 381 patients with UC were CDAB positive. Antibiotic exposure within 3 months prior to the study (P = 0.004), hospitalization within 1 month prior to the study (P = 0.025), systemic use of steroids (P = 0.002) and active cytomegalovirus (CMV) infection (P = 0.001) were higher in CDI than non-CDI patients. Binary logistic regression analysis revealed that CMV infection was associated with CDI (odds ratio = 13.502, 95% confidence interval 1.307-139.512, P = 0.029). UC patients with C. difficile and CMV co-infection had more severe colonoscopic features.

CONCLUSIONS

Recent use of antibiotics, prior hospitalization and systemic use of steroids increased the risk of CDI. CMV infection was an independent risk factor of CDI in patients with UC.

Clostridium difficile infection in pregnant and postpartum women in 2 hospitals and a review of literature

BACKGROUND

Healthcare-associated Clostridium difficile infection (CDI) in pregnant/postpartum women is underreported, especially outside of North America. We report a cluster of cases in 2 neighboring secondary care hospitals in South-East England. The objective of this study was to identify the epidemiology and risk factors for infection.

METHODS

An investigation into a cluster of cases of confirmed CDI in pregnant/postpartum women was performed over a 12-month period, from June 2016 to June 2017.

RESULTS

Eleven cases, in 10 patients, were identified, including 1 patient who had a relapse. Eight of 10 patients developed symptoms after hospital discharge. All patients had received broad-spectrum antibiotics prior to CDI onset. Environmental vectors, such as labor room mattresses, that were found difficult to effectively decontaminate after heavy contamination with blood, feces, and other body fluids may have been possible reservoirs. An infection control care bundle was successful in preventing further cases.

CONCLUSIONS

Antibiotic use and exposure to the organism in a contaminated labor room environment are likely risk factors for healthcare-associated CDI in postpartum women. Active surveillance is necessary to prevent these infections, as these cases often present after hospital discharge.

Intrinsic Class D β-Lactamases of Clostridium difficile

Clostridium difficile is the causative agent of the deadly C. difficile infection. Resistance of the pathogen to β-lactam antibiotics plays a major role in the development of the disease, but the mechanism of resistance is currently unknown. We discovered that C. difficile encodes class D β-lactamases, i.e., CDDs, which are intrinsic to this species. We studied two CDD enzymes, CDD-1 and CDD-2, and showed that they display broad-spectrum, high catalytic efficiency against various β-lactam antibiotics, including penicillins and expanded-spectrum cephalosporins. We demonstrated that the cdd genes are poorly expressed under the control of their own promoters and contribute only partially to the observed resistance to β-lactams. However, when the cdd1 gene was expressed under the control of efficient promoters in the antibiotic-sensitive Clostridium cochlearium strain, it produced high-level resistance to β-lactams. Taken together, the results determined in this work demonstrate the existence in C. difficile of intrinsic class D β-lactamases which constitute a reservoir of highly potent enzymes capable of conferring broad-spectrum, clinically relevant levels of resistance to β-lactam antibiotics. This discovery is a significant contribution to elucidation of the mechanism(s) of resistance of the clinically important pathogen C. difficile to β-lactam antibiotics.IMPORTANCEC. difficile is a spore-forming anaerobic bacterium which causes infection of the large intestine with high mortality rates. The C. difficile infection is difficult to prevent and treat, as the pathogen is resistant to many antimicrobial agents. Prolonged use of β-lactam antibiotics for treatment of various infectious diseases triggers the infection, as these drugs suppress the abundance of protective gut bacteria, allowing the resistant C. difficile bacteria to multiply. While resistance of C. difficile to β-lactam antibiotics plays the major role in the development of the disease, the mechanism of resistance is unknown. The significance of our research is in the discovery in C. difficile of β-lactamases, enzymes that destroy β-lactam antibiotics. These findings ultimately can help to combat deadly C. difficile infections.

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.

ASID/ACIPC position statement - Infection control for patients with Clostridium difficile infection in healthcare facilities

BACKGROUND

In 2011, the Australasian Society for Infectious Diseases (ASID) and the Australian Infection Control Association (AICA), now known as the Australasian College of Infection Prevention and Control (ACIPC), produced a position statement on infection control requirements for preventing and controlling Clostridium difficile infection (CDI) in healthcare settings.

METHODS

The statement updated in 2017 to reflect new literature available .The authors reviewed the 2011 position statement and critically appraised new literature published between 2011 and 2017 and relevant current infection control guidelines to identify where new evidence had become available or best practice had changed.

RESULTS

The position statement was updated incorporating the new findings. A draft version of the updated position statement was circulated for consultation to members of ASID and ACIPC. The authors responded to all comments received and updated the position statement.

CONCLUSIONS

This updated position statement emphasizes the importance of health service organizations having evidence-based infection prevention and control programs and comprehensive antimicrobial stewardship programs, to ensure the risk of C. difficile acquisition, transmission and infection is minimised.

Vulnerability of long-term care facility residents to Clostridium difficile infection due to microbiome disruptions

Aging presents a significant risk factor for Clostridium difficile infection (CDI). A disproportionate number of CDIs affect individuals in long-term care facilities compared with the general population, likely due to the vulnerable nature of the residents and shared environment. Review of the literature cites a number of underlying medical conditions such as the use of antibiotics, proton pump inhibitors, chemotherapy, renal disease and feeding tubes as risk factors. These conditions alter the intestinal environment through direct bacterial killing, changes to pH that influence bacterial stabilities or growth, or influence nutrient availability that direct population profiles. In this review, we examine some of the contributing risk factors for elderly associated CDI and the toll they take on the microbiome.

Clinical review of Clostridium difficile infection: an update on treatment and prevention

INTRODUCTION

Clostridium difficile infection (CDI) has become a significant healthcare-associated infection and is strongly associated with antibiotic use. Practice guidelines have recently been revised incorporating updated recommendations for diagnosis, treatment, and prevention.

AREAS COVERED

This review discusses updated aspects of CDI management. New and emerging pharmacologic options for treatment and prevention are reviewed.

EXPERT OPINION

Metronidazole is associated with lower rates of treatment success compared to vancomycin and should no longer be used as primary therapy for the first episode of CDI or recurrent disease. Vancomycin or fidaxomicin are now recommended for first-line therapy for most cases of CDI. Fecal microbiota transplant is effective and safe for the treatment of recurrent CDI. Evidence supports the use of fidaxomicin and bezlotoxumab for prevention of recurrent CDI; however, the costs associated with these therapies may limit their use. Validated risk prediction tools are needed to identify patients most likely to benefit from these treatments. Future advancements in microbiota targeting treatments will emerge as promising alternatives to standard CDI treatments. Antibiotic stewardship and infection control measures will remain essential components for CDI management.

Antibiotic stewardship: Why we must, how we can

Improving our antibiotic use is critical to the safety of our patients and the future of medicine. This can improve patient outcomes, save money, reduce resistance, and help prevent negative consequences such as Clostridium difficile infection. The US Centers for Disease Control and Prevention (CDC) is undertaking a nationwide effort to appropriately improve antibiotic use in inpatient and outpatient settings.

Para-cresol production by Clostridium difficile affects microbial diversity and membrane integrity of Gram-negative bacteria

Clostridium difficile is a Gram-positive spore-forming anaerobe and a major cause of antibiotic-associated diarrhoea. Disruption of the commensal microbiota, such as through treatment with broad-spectrum antibiotics, is a critical precursor for colonisation by C. difficile and subsequent disease. Furthermore, failure of the gut microbiota to recover colonisation resistance can result in recurrence of infection. An unusual characteristic of C. difficile among gut bacteria is its ability to produce the bacteriostatic compound para-cresol (p-cresol) through fermentation of tyrosine. Here, we demonstrate that the ability of C. difficile to produce p-cresol in vitro provides a competitive advantage over gut bacteria including Escherichia coli, Klebsiella oxytoca and Bacteroides thetaiotaomicron. Metabolic profiling of competitive co-cultures revealed that acetate, alanine, butyrate, isobutyrate, p-cresol and p-hydroxyphenylacetate were the main metabolites responsible for differentiating the parent strain C. difficile (630Δerm) from a defined mutant deficient in p-cresol production. Moreover, we show that the p-cresol mutant displays a fitness defect in a mouse relapse model of C. difficile infection (CDI). Analysis of the microbiome from this mouse model of CDI demonstrates that colonisation by the p-cresol mutant results in a distinctly altered intestinal microbiota, and metabolic profile, with a greater representation of Gammaproteobacteria, including the Pseudomonales and Enterobacteriales. We demonstrate that Gammaproteobacteria are susceptible to exogenous p-cresol in vitro and that there is a clear divide between bacterial Phyla and their susceptibility to p-cresol. In general, Gram-negative species were relatively sensitive to p-cresol, whereas Gram-positive species were more tolerant. This study demonstrates that production of p-cresol by C. difficile has an effect on the viability of intestinal bacteria as well as the major metabolites produced in vitro. These observations are upheld in a mouse model of CDI, in which p-cresol production affects the biodiversity of gut microbiota and faecal metabolite profiles, suggesting that p-cresol production contributes to C. difficile survival and pathogenesis.

Hospital acquired vancomycin resistant enterococci in surgical intensive care patients - a prospective longitudinal study

Background

Vancomycin resistant enterococci (VRE) occur with enhanced frequency in hospitalised patients. This study elucidates the prevalence of VRE on admission among surgical intensive care unit (SICU) patients, whether these patients are at special risk for VRE acquisition and which risk factors support this process.

Methods

Patients admitted to SICUs of the University Hospital Münster were examined during August-October 2017. VRE screening was performed within 48 h after admission and directly prior to discharge of patients. In parallel risk factors were recorded to estimate their effect on VRE acquisition during SICU stay.

Results

In total, 374 patients (68% male) with a median age of 66 years were admitted to one of the SICUs during the investigation period. Of all, 336 patients (89.8%) were screened on admission and 268 (71.7%) on discharge. Nine patients were admitted with previously known VRE colonisation. Twelve (3.6%) further patients were VRE positive on admission. During ICU stay, eight (3.0%) additional patients turned out to be VRE colonised. Risk factors found to be significantly associated with VRE acquisition were median length of stay on the ICU (14 vs. 3 days; p = 0.01), long-term dialysis (12.5% vs. 2.0% of patients; p = 0.05), and antibiotic treatment with flucloxacillin (28.6% vs. 7.2% of patients; p = 0.01) or piperacillin/tazobactam (57.1% vs. 26.6% of patients; p = 0.01).

Conclusions

SICU patients are not at special risk for VRE acquisition. Previous stay on a SICU should therefore not be considered as specific risk factor for VRE colonisation.

Healthcare-acquired infections: prevention strategies

Healthcare-acquired infections (HAI) impact on patient care and have cost implications for the Australian healthcare system. The management of HAI is exacerbated by rising rates of antimicrobial resistance (AMR). Health-care workers and a contaminated hospital environment are increasingly implicated in the transmission and persistence of multi-resistant organisms (MRO), as well as other pathogens, such as Clostridium difficile. This has resulted in a timely focus on a range of HAI prevention actions. Core components include antimicrobial stewardship, to reduce overuse and ensure evidence-based antimicrobial use; infection prevention strategies, to control MRO - particularly methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus spp. (VRE) and, more recently, multi-resistant Gram-negative bacteria; enhanced institutional investment in hand hygiene; hospital cleaning and disinfection; and the development of prescribing guidelines and standards of care. AMR surveillance and comparisons of prescribing are useful feedback activities once effectively communicated to end users. Successful implementation of these strategies requires cultural shifts at local hospital level and, to tackle the serious threat posed by AMR, greater co-ordination at a national level. HAI prevention needs to be multi-modal, requires broad healthcare collaboration, and the strong support and accountability of all medical staff.

Clostridium difficile infection is associated with graft loss in solid organ transplant recipients

Clostridium difficile infection (CDI) is a leading cause of infectious diarrhea in solid organ transplant recipients (SOT). We aimed to assess incidence, risk factors, and outcome of CDI within the Swiss Transplant Cohort Study (STCS). We performed a case-control study of SOT recipients in the STCS diagnosed with CDI between May 2008 and August 2013. We matched 2 control subjects per case by age at transplantation, sex, and transplanted organ. A multivariable analysis was performed using conditional logistic regression to identify risk factors and evaluate outcome of CDI. Two thousand one hundred fifty-eight SOT recipients, comprising 87 cases of CDI and 174 matched controls were included. The overall CDI rate per 10 000 patient days was 0.47 (95% confidence interval ([CI] 0.38-0.58), with the highest rate in lung (1.48, 95% CI 0.93-2.24). In multivariable analysis, proven infections (hazard ratio [HR] 2.82, 95% CI 1.29-6.19) and antibiotic treatments (HR 4.51, 95% CI 2.03-10.0) during the preceding 3 months were independently associated with the development of CDI. Despite mild clinical presentations, recipients acquiring CDI posttransplantation had an increased risk of graft loss (HR 2.24, 95% CI 1.15-4.37; P = .02). These findings may help to improve the management of SOT recipients.

Antimicrobial Stewardship in Long-Term Care Facilities: Approaches to Creating an Antibiogram when Few Bacterial Isolates Are Cultured Annually

Antibiograms are important clinical tools to report and track antibiotic susceptibility and help guide empiric antimicrobial therapy. Antibiograms support compliance with antimicrobial stewardship (AMS) requirements from the Centers for Medicare and Medicaid Services and are in line with recommendations from the Centers for Disease Control and Prevention Core Elements of AMS for nursing homes/long-term care facilities (LTCFs). Unlike most acute-care settings, LTCFs are challenged in creating antibiograms because of the low number of bacterial isolates collected annually. Determining the best methodology for creating clinically useful antibiograms for LTCFs needs to be explored. Possible approaches include (1) extending the isolate data beyond 1 year, (2) combining isolate data from the same geographic region, (3) using a nearby acute-care facility's antibiogram as a proxy, or (4) collapsing isolate data. This article discusses the benefits and limitations of each approach.

Mechanistic Insights in the Success of Fecal Microbiota Transplants for the Treatment of Clostridium difficile Infections

Fecal microbiota transplantation has proven to be an effective treatment for infections with the gram-positive enteropathogen Clostridium difficile. Despite its effectiveness, the exact mechanisms that underlie its success are largely unclear. In this review, we highlight the pleiotropic effectors that are transferred during fecal microbiota transfer and relate this to the C. difficile lifecycle. In doing so, we show that it is likely that multiple factors contribute to the elimination of symptoms of C. difficile infections after fecal microbiota transplantation.

The Intersection Between Colonization Resistance, Antimicrobial Stewardship, and Clostridium difficile

PURPOSE OF REVIEW

Colonization resistance refers to the innate defense provided by the indigenous microbiota against colonization by pathogenic organisms. We aim to describe how this line of defense is deployed against Clostridium difficile and what the implications are for interventions directed by Antimicrobial Stewardship Programs.

RECENT FINDINGS

The indigenous microbiota provides colonization resistance through depletion of nutrients, prevention of access to adherence sites within the gut mucosa, production of inhibitory substances, and stimulation of the host's immune system. The ability to quantify colonization resistance could provide information regarding periods of maximal vulnerability to colonization with pathogens and also allow the identification of mechanisms of restoration of colonization resistance. Methods utilized to determine the composition of the gut microbiota include sequencing technologies and measurement of concentration of specific bacterial metabolites. Use of innovations in the quantification of colonization resistance can expand the role of Antimicrobial Stewardship from prevention of disruption of the indigenous microbiota to restoration of colonization resistance.