Asymptomatic Clostridium difficile colonization: epidemiology and clinical implications

Metabolic Modeling to Interrogate Microbial Disease: A Tale for Experimentalists

The explosion of microbiome analyses has helped identify individual microorganisms and microbial communities driving human health and disease, but how these communities function is still an open question. For example, the role for the incredibly complex metabolic interactions among microbial species cannot easily be resolved by current experimental approaches such as 16S rRNA gene sequencing, metagenomics and/or metabolomics. Resolving such metabolic interactions is particularly challenging in the context of polymicrobial communities where metabolite exchange has been reported to impact key bacterial traits such as virulence and antibiotic treatment efficacy. As novel approaches are needed to pinpoint microbial determinants responsible for impacting community function in the context of human health and to facilitate the development of novel anti-infective and antimicrobial drugs, here we review, from the viewpoint of experimentalists, the latest advances in metabolic modeling, a computational method capable of predicting metabolic capabilities and interactions from individual microorganisms to complex ecological systems. We use selected examples from the literature to illustrate how metabolic modeling has been utilized, in combination with experiments, to better understand microbial community function. Finally, we propose how such combined, cross-disciplinary efforts can be utilized to drive laboratory work and drug discovery moving forward.

High Prevalence of Multidrug-Resistant Clostridioides difficile Following Extensive Use of Antimicrobials in Hospitalized Patients in Kenya

Introduction

Clostridioides difficile is a neglected pathogen in many African countries as it is generally not regarded as one of the major contributors toward the diarrheal disease burden in the continent. However, several studies have suggested that C. difficile infection (CDI) may be underreported in many African settings. The aim of this study was to determine the prevalence of CDI in hospitalized patients, evaluate antimicrobial exposure, and detect toxin and antimicrobial resistance profiles of the isolated C. difficile strains.

Methods

In this cross-sectional study, 333 hospitalized patients with hospital-onset diarrhoea were selected. The stool samples were collected and cultured on cycloserine-cefoxitin egg yolk agar (CCEY). Isolates were presumptively identified by phenotypic characteristics and Gram stain and confirmed by singleplex real-time PCR (qPCR) assays detecting the species-specific tpi gene, toxin A (tcdA) gene, toxin B (tcdB) gene, and the binary toxin (cdtA/cdtB) genes. Confirmed C. difficile isolates were tested against a panel of eight antimicrobials (vancomycin, metronidazole, rifampicin, ciprofloxacin, tetracycline, clindamycin, erythromycin, and ceftriaxone) using E-test strips.

Results

C. difficile was detected in 57 (25%) of diarrheal patients over the age of two, 56 (98.2%) of whom received antimicrobials before the diarrheal episode. Amongst the 71 confirmed isolates, 69 (97.1%) harbored at least one toxin gene. More than half of the toxigenic isolates harbored a truncated tcdA gene. All isolates were sensitive to vancomycin, while three isolates (2.1%) were resistant to metronidazole (MIC >32 mg/L). High levels of resistance were observed to rifampicin (65/71, 91.5%), erythromycin (63/71, 88.7%), ciprofloxacin (59/71, 83.1%), clindamycin (57/71, 80.3%), and ceftriaxone (36/71, 50.7.8%). Among the resistant isolates, 61 (85.9%) were multidrug-resistant.

Conclusion

Multidrug-resistant C. difficile strains were a significant cause of healthcare facility-onset C. difficile infections in patients with prior antimicrobial exposure in this Kenyan hospital.

Computational modeling of the gut microbiota reveals putative metabolic mechanisms of recurrent Clostridioides difficile infection

Approximately 30% of patients who have Clostridioides difficile infection (CDI) will suffer at least one incident of reinfection. While the underlying causes of CDI recurrence are poorly understood, interactions between C. difficile and commensal gut bacteria are thought to play an important role. In this study, an in silico pipeline was used to process 16S rRNA gene amplicon sequence data of 225 stool samples from 93 CDI patients into sample-specific models of bacterial community metabolism. Clustered metabolite production rates generated from post-diagnosis samples generated a high Enterobacteriaceae abundance cluster containing disproportionately large numbers of recurrent samples and patients. This cluster was predicted to have significantly reduced capabilities for secondary bile acid synthesis but elevated capabilities for aromatic amino acid catabolism. When applied to 16S sequence data of 40 samples from fecal microbiota transplantation (FMT) patients suffering from recurrent CDI and their stool donors, the community modeling method generated a high Enterobacteriaceae abundance cluster with a disproportionate large number of pre-FMT samples. This cluster also was predicted to exhibit reduced secondary bile acid synthesis and elevated aromatic amino acid catabolism. Collectively, these in silico predictions suggest that Enterobacteriaceae may create a gut environment favorable for C. difficile spore germination and/or toxin synthesis.

Interfacility patient sharing and Clostridioides difficile infection incidence in the Ontario hospital system: A 13-year cohort study

OBJECTIVE

Interfacility patient movement plays an important role in the dissemination of antimicrobial-resistant organisms throughout healthcare systems. We evaluated how 3 alternative measures of interfacility patient sharing were associated with C. difficile infection incidence in Ontario acute-care facilities.

DESIGN

The cohort included adult acute-care facility stays of ≥3 days between April 2003 and March 2016. We measured 3 facility-level metrics of patient sharing: general patient importation, incidence-weighted patient importation, and C. difficile case importation. Each of the 3 patient-sharing metrics were examined against the incidence of C. difficile infection in the facility per 1,000 stays, using Poisson regression models.

RESULTS

The analyzed cohort included 6.70 million stays at risk of C. difficile infection across 120 facilities. Over the 13-year period, we included 62,189 new cases of healthcare-associated CDI (incidence, 9.3 per 1,000 stays). After adjustment for facility characteristics, general importation was not strongly associated with C. difficile infection incidence (risk ratio [RR] per doubling, 1.10; 95% confidence interval [CI], 0.97-1.24; proportional change in variance [PCV], -2.0%). Incidence-weighted (RR per doubling, 1.18; 95% CI, 1.06-1.30; PCV, -8.4%) and C. difficile case importation (RR per doubling, 1.43; 95% CI, 1.29-1.58; PCV, -30.1%) were strongly associated with C. difficile infection incidence.

CONCLUSIONS

In this 13-year study of acute-care facilities in Ontario, interfacility variation in C. difficile infection incidence was associated with importation of patients from other high-incidence acute-care facilities or specifically of patients with a recent history of C. difficile infection. Regional infection control strategies should consider the potential impact of importation of patients at high risk of C. difficile shedding from outside facilities.

Does over a century of aerobic phage work provide a solid framework for the study of phages in the gut?

Bacterial viruses (bacteriophages, phages) of the gut have increasingly become a focus in microbiome studies, with an understanding that they are likely key players in health and disease. However, characterization of the virome remains largely based on bioinformatic approaches, with the impact of these viromes inferred based on a century of knowledge from aerobic phage work. Studying the phages infecting anaerobes is difficult, as they are often technically demanding to isolate and propagate. In this review, we primarily discuss the phages infecting three well-studied anaerobes in the gut: Bifidobacterium, Clostridia and Bacteroides, with a particular focus on the challenges in isolating and characterizing these phages. We contrast the lessons learned from these to other anaerobic work on phages infecting facultative anaerobes of the gut: Enterococcus and Lactobacillus. Phages from the gut do appear to adhere to the lessons learned from aerobic work, but the additional challenges of working on them has required ingenious new approaches to enable their study. This, in turn, has uncovered remarkable biology likely underpinning phage-host relationships in many stable environments.

Predictors of Clostridioides difficile Infection Among Asymptomatic, Colonized Patients: A Retrospective Cohort Study

BACKGROUND

Asymptomatic patients colonized with Clostridioides difficile are at risk of developing C. difficile infection (CDI), but the factors associated with disease onset are poorly understood. Our aims were to identify predictors of hospital-onset CDI (HO-CDI) among colonized patients and to explore the potential benefits of primary prophylaxis to prevent CDI.

METHODS

We conducted a retrospective cohort study in a tertiary academic institution. Colonized patients were identified by detecting the tcdB gene by polymerase chain reaction on a rectal swab. Univariate and multivariate logistic regression analyses were used to identify predictors of HO-CDI.

RESULTS

There were 19 112 patients screened, from which 960 (5%) colonized patients were identified: 513 met the inclusion criteria. Overall, 39 (7.6%) developed a HO-CDI, with a 30-day attributable mortality of 15%. An increasing length of stay (adjusted odds ratio [aOR] per day, 1.03; P = .006), exposure to multiple classes of antibiotics (aOR per class, 1.45; P = .02), use of opioids (aOR, 2.78; P = .007), and cirrhosis (aOR 5.49; P = .008) were independently associated with increased risks of HO-CDI, whereas the use of laxatives was associated with a lower risk of CDI (aOR 0.36; P = .01). Among the antimicrobials, B-lactam with B-lactamase inhibitors (OR 3.65; P < .001), first-generation cephalosporins (OR 2.38; P = .03), and carbapenems (OR 2.44; P = .03) correlated with the greatest risk of HO-CDI. By contrast, patient age, the use of proton pump inhibitors, and the use of primary prophylaxis were not significant predictors of HO-CDI.

CONCLUSIONS

This study identifies several factors that are associated with CDI among colonized patients. Whether modifying these variables could decrease the risk of CDI should be investigated.

Prognostic role of perioperative acid-base disturbances on the risk of Clostridioides difficile infection in patients undergoing cardiac surgery

BACKGROUND

It is unclear whether acid-base balance disturbances during the perioperative period may impact Clostridium difficile infection (CDI), which is the third most common major infection following cardiac surgery. We hypothesized that perioperative acid-base abnormalities including lactate disturbances may predict the probability of incidence of CDI in patients after cardiac procedures.

METHODS

Of the 12,235 analyzed patients following cardiac surgery, 143 (1.2%) developed CDI. The control group included 200 consecutive patients without diarrhea, who underwent cardiac procedure within the same period of observation. Pre-, intra and post-operative levels of blood gases, as well as lactate and glucose concentrations were determined. Postoperatively, arterial blood was drawn four times: immediately after surgery and successively; 4, 8 and 12 h following the procedure.

RESULTS

Baseline pH was lower and PaO2 was higher in CDI patients (p < 0.001 and p = 0.001, respectively). Additionally, these patients had greater base deficiency at each of the analyzed time points (p < 0.001, p = 0.004, p = 0.012, p = 0.001, p = 0.016 and p = 0.001, respectively). Severe hyperlactatemia was also more common in CDI patients; during the cardiac procedure, 4 h and 12 h after surgery (p = 0.027, p = 0.004 and p = 0.001, respectively). Multivariate logistic regression analysis revealed that independent risk factors for CDI following cardiac surgery were as follows: intraoperative severe hyperlactatemia (OR 2.387, 95% CI 1.155-4.933, p = 0.019), decreased lactate clearance between values immediately and 12 h after procedure (OR 0.996, 95% CI 0.994-0.999, p = 0.013), increased age (OR 1.045, 95% CI 1.020-1.070, p < 0.001), emergent surgery (OR 2.755, 95% CI 1.565-4.848, p < 0.001) and use of antibiotics other than periprocedural prophylaxis (OR 2.778, 95% CI 1.690-4.565, p < 0.001).

CONCLUSION

This study is the first to show that perioperative hyperlactatemia and decreased lactate clearance may be predictors for occurrence of CDI after cardiac surgery.

Faecal microbiota transplantation for Clostridioides difficile: mechanisms and pharmacology

Faecal microbiota transplantation (FMT) has emerged as a remarkably successful treatment for recurrent Clostridioides difficile infection that cannot be cured with antibiotics alone. Understanding the complex biology and pathogenesis of C. difficile infection, which we discuss in this Perspective, is essential for understanding the potential mechanisms by which FMT cures this disease. Although FMT has already entered clinical practice, different microbiota-based products are currently in clinical trials and are vying for regulatory approval. However, all these therapeutics belong to an entirely new class of agents that require the development of a new branch of pharmacology. Characterization of microbiota therapeutics uses novel and rapidly evolving technologies and requires incorporation of microbial ecology concepts. Here, we consider FMT within a pharmacological framework, including its essential elements: formulation, pharmacokinetics and pharmacodynamics. From this viewpoint, multiple gaps in knowledge become apparent, identifying areas that require systematic research. This knowledge is needed to help clinical providers use microbiota therapeutics appropriately and to facilitate development of next-generation microbiota products with improved safety and efficacy. The discussion here is limited to FMT as a representative of microbiota therapeutics and recurrent C. difficile as the indication; however, consideration of the intrinsic basic principles is relevant to this entire class of microbiota-based therapeutics.

Faecal transplantation and Clostridioides difficile infection

Faecal microbiota transplantation (FMT), known equally well as faecal transplantation or faecal bacteriotherapy, is the process of implanting the faecal suspension containing balanced microbiota from a healthy donor to the colon of a recipient patient. Excessive growth of Clostridioides difficile (C difficile) in the intestinal microbiota resulting from antibiotic consumption is currently a rising threat to public health. FMT is one of the most important, newer approaches to treating C difficile infections. Since C difficile is regarded as an opportunistic bacterium triggering disease in conditions of disturbed homeostasis of the intestinal microbiota, restoration of healthy intestinal microflora facilitates suppression of toxic strain of C difficile by anaerobic bacteria of normal intestinal microflora with concomitant cure. Nurses have important role in caring for patients after faecal transplantation.

Antimicrobial resistance in enteric bacteria: current state and next-generation solutions

Antimicrobial resistance is one of the largest threats to global health and imposes substantial burdens in terms of morbidity, mortality, and economic costs. The gut is a key conduit for the genesis and spread of antimicrobial resistance in enteric bacterial pathogens. Distinct bacterial species that cause enteric disease can exist as invasive enteropathogens that immediately evoke gastrointestinal distress, or pathobionts that can arise from established bacterial commensals to inflict dysbiosis and disease. Furthermore, various environmental reservoirs and stressors facilitate the evolution and transmission of resistance. In this review, we present a comprehensive discussion on circulating resistance profiles and gene mobilization strategies of the most problematic species of enteric bacterial pathogens. Importantly, we present emerging approaches toward surveillance of pathogens and their resistance elements as well as promising treatment strategies that can circumvent common resistance mechanisms.

Risk factors for Clostridioides difficile colonization among hospitalized adults: A meta-analysis and systematic review

OBJECTIVE

To identify risk factors for asymptomatic Clostridioides difficile colonization among hospitalized adults utilizing a meta-analysis, which may enable early identification of colonized patients at risk of spreading C. difficile.

DESIGN

Meta-analysis and systematic review.

METHODS

We systematically searched MEDLINE, Scopus, Web of Science, and EMBASE from January 1, 1975, to February 15, 2020, for articles related to C. difficile colonization among hospitalized adults. Studies with multivariable analyses evaluating risk factors for asymptomatic colonization were eligible.

RESULTS

Among 5,506 studies identified in the search, 19 studies met the inclusion criteria. Included studies reported 20,334 adult patients of whom 1,588 were asymptomatically colonized with C. difficile. Factors associated with an increased risk of colonization were hospitalization in the previous 6 months (OR, 2.18; 95% CI, 1.86-2.56; P < .001), use of gastric acid suppression therapy within the previous 8 weeks (OR, 1.42; 95% CI, 1.17-1.73; P < .001), tube feeding (OR, 2.02; 95% CI, 1.06-3.85; P = .03), and corticosteroid use in the previous 8 weeks (OR, 1.58; 95% CI, 1.14-2.17; P = .006). Receipt of antibiotics in the previous 3 months (OR, 1.37; 95% CI, 0.94-2.01; P = .10) was not associated with statistically significant effects on risk of colonization.

CONCLUSIONS

C. difficile colonization was significantly associated with previous hospitalization, gastric acid suppression, tube feeding, and corticosteroid use. Recognition of these risk factors may assist in identifying asymptomatic carriers of C. difficile and taking appropriate measures to reduce transmission.

Clostridioides (Clostridium) difficile Pacemaker Infection

Clostridioides difficile is the leading cause of antibiotic-associated nosocomial diarrhea, but extra-intestinal manifestations are rare. We describe the first documented case of bacteraemia with pacemaker pocket and lead infection with the toxigenic C. difficile ribotype 014 with a lack of abdominal symptoms. The patient underwent pacemaker extraction and treatment with intravenous and oral vancomycin. Genotyping and molecular subtyping revealed clonality between pacemaker and intestinal isolates. This case illustrates the risk of intravascular device infections due to C. difficile. Even asymptomatic C. difficile colonization might pose a risk for prosthetic material infection.

Molecular and non-molecular approaches to etiologic diagnosis of gastroenteritis

Gastroenteritis is a major cause of mortality and morbidity globally and rapid identification of the causative pathogen is important for appropriate treatment and patient management, implementation of effective infection control measures, reducing hospital length of stay, and reducing overall medical costs. Although stool culture and microscopic examination of diarrheal stool has been the primary method for laboratory diagnosis, culture-independent proteomic and genomic tests are receiving increased attention. Antigen tests for stool pathogens are routinely implemented as rapid and simple analytics whereas molecular tests are now available in various formats from high complexity to waived point-of-care tests. In addition, metagenomic next-generation sequencing stands poised for use as a method for both diagnosis and routine characterization of the gut microbiome in the very near future. Analysis of host biomarkers as indicators of infection status and pathogenesis may also become important for prediction, diagnosis, and monitoring of gastrointestinal infection. Here we review current methods and emerging technologies for the etiologic diagnosis of gastroenteritis in the clinical laboratory. Benefits and limitations of these evolving methods are highlighted.

Implementation of a Bowel Protocol to Improve Enteral Nutrition and Reduce Clostridium difficile Testing

BACKGROUND

Underfeeding is common among adult patients receiving enteral nutrition. Constipation and diarrhea have been associated with low enteral nutrition volume in critically ill patients. In patients with diarrhea, Clostridium difficile is often suspected and tested for, although medications, illness, or enteral formulas are usually the cause. The use of bowel protocols to proactively address constipation, diarrhea, and inappropriate testing for hospital-onset C difficile infection, thereby improving enteral nutrition, remains unclear.

OBJECTIVE

To evaluate the efficacy of implementing protocols to decrease constipation, diarrhea, and inappropriate testing for hospital-onset C difficile infection, and to deliver larger enteral nutrition volumes in a critical care unit.

METHODS

A prospective convenience sample was used. The primary outcome was the proportion of patients receiving greater than or equal to 80% of their prescribed caloric volume 1 week (minimum 4 days) after initiating enteral nutrition. Rates of testing for hospital-onset C difficile infection were analyzed before and after the protocol was implemented.

RESULTS

After the protocol was implemented, patients experienced significant increases in delivery of enteral nutrition volume-up to 78% of the goal volume (P = .048). The standardized infection ratio of hospital-onset C difficile infection decreased 43% (P = .04).

CONCLUSIONS

The implementation of bowel protocols improved delivery of total enteral volumes and reduced inappropriate testing for hospital-onset infections with C difficile, and they may improve patient safety and facilitate positive patient outcomes.

Management of Clostridioides difficile infection in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD) is a common diarrheal illness with gastrointestinal and extraintestinal manifestations and complications. The most common infectious complication associated with IBD is Clostridioides difficile infection (CDI). Active IBD predisposes to CDI due to alterations in the gut microbiome. C. difficile is a toxin producing bacterium leading to worsening of underlying IBD, increasing the risk of IBD treatment failure and an increased risk of hospitalization and surgery. Since the symptoms of CDI overlap with those of an IBD flare; it is prudent to recognize that the diagnosis of CDI is challenging and diagnostic tests (nucleic-acid and toxin-based assays) should be interpreted in context of symptoms and test performance. First line treatments for management of CDI in IBD include vancomycin or fidaxomicin. Recurrence prevention strategies should be implemented to mitigate recurrent CDI risk. One needs to monitor IBD disease progression and manage immunosuppression. The risk of recurrent CDI after a primary infection is higher in IBD compared to non-IBD patients. Microbiota restoration therapies are effective to prevent recurrent CDI in IBD patients. This review summarizes the epidemiology, pathophysiology, diagnostic testing, outcomes and management of both CDI and IBD, in CDI complicating IBD.

COVID-19 and Clostridioides difficile infection (CDI): Possible implications for elderly patients

COVID-19 dramatically affects the elderly. Due to the large usage of antibiotics during the current pandemic and the gastrointestinal manifestations of COVID-19, the elderly population, hospitalized patients, residents in LTCFs and persons that survived the COVID-19 might be more prone to Clostridioides difficile infections (CDI). A renewed attention to CDI is necessary during the ongoing COVID-19 pandemic.

From Nursery to Nursing Home: Emerging Concepts in Clostridioides difficile Pathogenesis

Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacterium that infects the human gastrointestinal tract, causing a wide range of disorders that vary in severity from mild diarrhea to toxic megacolon and/or death. Over the past decade, incidence, severity, and costs associated with C. difficile infection (CDI) have increased dramatically in both the pediatric and adult populations. The factors driving this rapidly evolving epidemiology remain largely unknown but are likely due in part to previously unappreciated host, microbiota, and environmental factors. In this review, we will cover the risks and challenges of CDI in adult and pediatric populations and examine asymptomatic colonization in infants. We will also discuss the emerging role of diet, pharmaceutical drugs, and pathogen-microbiota interactions in C. difficile pathogenesis, as well as the impact of host-microbiota interactions in the manifestation of C. difficile-associated disease. Finally, we highlight new areas of research and novel strategies that may shed light on this complex infection and provide insights into the future of microbiota-based therapeutics for CDI.

Salicylanilide Analog Minimizes Relapse of Clostridioides difficile Infection in Mice

Clostridioides difficile infection (CDI) causes serious and sometimes fatal symptoms like diarrhea and pseudomembranous colitis. Although antibiotics for CDI exist, they are either expensive or cause recurrence of the infection due to their altering the colonic microbiota, which is necessary to suppress the infection. Here, we leverage a class of known membrane-targeting compounds that we previously showed to have broad inhibitory activity across multiple Clostridioides difficile strains while preserving the microbiome to develop an efficacious agent. A new series of salicylanilides was synthesized, and the most potent analog was selected through an in vitro inhibitory assay to evaluate its pharmacokinetic parameters and potency in a CDI mouse model. The results revealed reduced recurrence of CDI and diminished disturbance of the microbiota in mice compared to standard-of-care vancomycin, thus paving the way for novel therapy that can potentially target the cell membrane of C. difficile to minimize relapse in the recovering patient.

Association of Household Exposure to Primary Clostridioides difficile Infection With Secondary Infection in Family Members

Importance

Clostridioides difficile infection (CDI) is a common hospital-acquired infection. Whether family members are more likely to experience a CDI following CDI in another separate family member remains to be studied.

Objective

To determine the incidence of potential family transmission of CDI.

Design, Setting, and Participants

In this case-control study comparing the incidence of CDI among individuals with prior exposure to a family member with CDI to those without prior family exposure, individuals were binned into monthly enrollment strata based on exposure status (eg, family exposure) and confounding factors (eg, age, prior antibiotic use). Data were derived from population-based, longitudinal commercial insurance claims from the Truven Marketscan Commercial Claims and Encounters and Medicare Supplemental databases from 2001 to 2017. Households with at least 2 family members continuously enrolled for at least 1 month were eligible. CDI incidence was computed within each stratum. A regression model was used to compare incidence of CDI while controlling for possible confounding characteristics.

Exposures

Index CDI cases were identified using inpatient and outpatient diagnosis codes. Exposure risks 60 days prior to infection included CDI diagnosed in another family member, prior hospitalization, and antibiotic use.

Main Outcomes and Measures

The primary outcome was the incidence of CDI in a given monthly enrollment stratum. Separate analyses were considered for CDI diagnosed in outpatient or hospital settings.

Results

A total of 224 818 cases of CDI, representing 194 424 enrollees (55.9% female; mean [SD] age, 52.8 [22.2] years) occurred in families with at least 2 enrollees. Of these, 1074 CDI events (4.8%) occurred following CDI diagnosis in a separate family member. Prior family exposure was significantly associated with increased incidence of CDI, with an incidence rate ratio (IRR) of 12.47 (95% CI, 8.86-16.97); this prior family exposure represented the factor with the second highest IRR behind hospital exposure (IRR, 16.18 [95% CI, 15.31-17.10]). For community-onset CDI cases without prior hospitalization, the IRR for family exposure was 21.74 (95% CI, 15.12-30.01). Age (IRR, 9.90 [95% CI, 8.92-10.98] for ages ≥65 years compared with ages 0-17 years), antibiotic use (IRR, 3.73 [95% CI, 3.41-4.08] for low-risk and 14.26 [95% CI, 13.27-15.31] for high-risk antibiotics compared with no antibiotics), and female sex (IRR, 1.44 [95% CI, 1.36-1.53]) were also positively associated with incidence.

Conclusions and Relevance

This study found that individuals with family exposure may be at significantly greater risk for acquiring CDI, which highlights the importance of the shared environment in the transmission and acquisition of C difficile.

Detection of Clostridioides difficile by Real-time PCR in Young Children Does Not Predict Disease

OBJECTIVES

Diagnosing Clostridioides difficile infections in young children with high asymptomatic colonization is challenging. We compared the frequency of C difficile detection by polymerase chain reaction (PCR) in healthy control (HC) children with those with acute gastroenteritis (AGE) and evaluated fecal-lactoferrin and organism load as possible indicators of true C difficile infection disease.

METHODS

Stool was collected from children <2 years old with AGE and from HCs. C difficile was detected by real-time PCR, and lactoferrin was measured by enzyme-linked immunosorbent assay. Clinical data were obtained via interviews and chart review. Mann-Whitney U test and χ² tests were used for group comparisons.

RESULTS

Of 524 stools collected from 524 children (250 with AGE, 274 HCs), C difficile was detected less in children with AGE (14%, 36 of 250) than in HCs (28%, 76 of 274) stools (P < .0001). Among infants <1 year old (n = 297), C difficile was detected in 18% of children with AGE versus 32% of HCs (P < .005), and among children 1 to 2 years old (n = 227), C difficile was detected in 10% of children with AGE versus 21% of HCs (P < .02). There was no significant difference in C difficile PCR cycle threshold values between children with AGE and HCs or lactoferrin levels in C difficile PCR-positive versus -negative stools.

CONCLUSIONS

HC children <2 years of age had higher rates of C difficile detection by PCR than children with AGE; C difficile detection by real-time PCR alone is not a reliable means to diagnose C difficile disease in children <2 years old.

Some simple rules for estimating reproduction numbers in the presence of reservoir exposure or imported cases

For many diseases, the basic reproduction number (R0) is a threshold parameter for disease extinction or survival in isolated populations. However no human population is fully isolated from other human or animal populations. We use compartmental models to derive simple rules for the basic reproduction number in populations where an endemic disease is sustained by a combination of local transmission within the population and exposure from some other source: either a reservoir exposure or imported cases. We introduce the idea of a reservoir-driven or importation-driven disease: diseases that would become extinct in the population of interest without reservoir exposure or imported cases (since R0<1), but nevertheless may be sufficiently transmissible that many or most infections are acquired from humans in that population. We show that in the simplest case, R0<1 if and only if the proportion of infections acquired from the external source exceeds the disease prevalence and explore how population heterogeneity and the interactions of multiple strains affect this rule. We apply these rules in two case studies of Clostridium difficile infection and colonisation: C. difficile in the hospital setting accounting for imported cases, and C. difficile in the general human population accounting for exposure to animal reservoirs. We demonstrate that even the hospital-adapted, highly-transmissible NAP1/RT027 strain of C. difficile had a reproduction number <1 in a landmark study of hospitalised patients and therefore was sustained by colonised and infected admissions to the study hospital. We argue that C. difficile should be considered reservoir-driven if as little as 13.0% of transmission can be attributed to animal reservoirs.

Modelling diverse sources of Clostridium difficile in the community: importance of animals, infants and asymptomatic carriers

Clostridium difficile infections (CDIs) affect patients in hospitals and in the community, but the relative importance of transmission in each setting is unknown. We developed a mathematical model of C. difficile transmission in a hospital and surrounding community that included infants, adults and transmission from animal reservoirs. We assessed the role of these transmission routes in maintaining disease and evaluated the recommended classification system for hospital- and community-acquired CDIs. The reproduction number in the hospital was <1 (range: 0.16–0.46) for all scenarios. Outside the hospital, the reproduction number was >1 for nearly all scenarios without transmission from animal reservoirs (range: 1.0–1.34). However, the reproduction number for the human population was <1 if a minority (>3.5–26.0%) of human exposures originated from animal reservoirs. Symptomatic adults accounted for <10% transmission in the community. Under conservative assumptions, infants accounted for 17% of community transmission. An estimated 33–40% of community-acquired cases were reported but 28–39% of these reported cases were misclassified as hospital-acquired by recommended definitions. Transmission could be plausibly sustained by asymptomatically colonised adults and infants in the community or exposure to animal reservoirs, but not hospital transmission alone. Under-reporting of community-onset cases and systematic misclassification underplays the role of community transmission.

An Overview of the Molecular Methods in the Diagnosis of Gastrointestinal Infectious Diseases

Gastrointestinal infectious diseases are very common worldwide and an important cause of morbidity and mortality, particularly in infants in developing countries. Diarrhea and other intestinal infections are caused by a wide range of bacteria, viruses, protozoa, and parasites. Conventional diagnosis of these infections is performed by culture, microscopy, and antigen detection immunoassays. The traditional culture and microscopy procedures are time-consuming, lack sensitivity, and require special laboratory setup and well-trained staff. However, based on the advancement in the molecular diagnostics and with the introduction of commercially available tests, traditional diagnostic techniques have been continuously replaced by these newer rapid antigen detection and molecular-based methods. This review summarizes and discusses the availability, advantages, and disadvantages of molecular methods in the detection and identification of human gastrointestinal pathogens.

Make Sure You Have a Safety Net: Updates in the Prevention and Management of Infectious Complications in Stem Cell Transplant Recipients

Hematopoietic stem cell transplant recipients are at increased risk of infection and immune dysregulation due to reception of cytotoxic chemotherapy; development of graft versus host disease, which necessitates treatment with immunosuppressive medications; and placement of invasive catheters. The prevention and management of infections in these vulnerable hosts is of utmost importance and a key “safety net” in stem cell transplantation. In this review, we provide updates on the prevention and management of CMV infection; invasive fungal infections; bacterial infections; Clostridium difficile infection; and EBV, HHV-6, adenovirus and BK infections. We discuss novel drugs, such as letermovir, isavuconazole, meropenem-vaborbactam and bezlotoxumab; weigh the pros and cons of using fluoroquinolone prophylaxis during neutropenia after stem cell transplantation; and provide updates on important viral infections after hematopoietic stem cell transplant (HSCT). Optimizing the prevention and management of infectious diseases by using the best available evidence will contribute to better outcomes for stem cell transplant recipients, and provide the best possible “safety net” for these immunocompromised hosts.

Trends in Health Care-Associated Infection Prevention Practices in US Veterans Affairs Hospitals From 2005 to 2017

IMPORTANCE

Health care-associated infection (HAI) is associated with substantial harm. To reduce HAI, the largest integrated health care system in the United States-the Veterans Health Administration-was an early adopter of infection prevention policies and initiatives. Whether these efforts translated into increased use of practices to prevent HAI in Veterans Affairs (VA) hospitals is unknown.

OBJECTIVE

To evaluate changes over time in infection prevention practices and the perception of the importance of infection prevention to hospital leadership.

DESIGN, SETTINGS, AND PARTICIPANTS

For this survey study, every 4 years between 2005 and 2017, infection preventionists were surveyed at all VA hospitals on use of practices associated with common HAIs, including central line-associated bloodstream infection (CLABSI), catheter-associated urinary tract infection (CAUTI), ventilator-associated pneumonia (VAP), and (beginning in 2013) Clostridioides difficile infection. Data analysis was performed from February 1, 2019, to July 1, 2019.

MAIN OUTCOMES AND MEASURES

Reported regular use of key infection prevention practices and perceived importance of infection prevention to hospital leadership.

RESULTS

Between 2005 and 2017, 320 total surveys were completed with response rates ranging from 59% (73 of 124) in 2017 to 80% (95 of 119) in 2005. Use of 12 different infection prevention practices increased. Since 2013, 92% (69 of 75) to 100% of VA hospitals reported regular use of key infection prevention practices for C difficile infection and CLABSI. In contrast, adoption of many practices to prevent CAUTI, although increasing, have lagged. Despite reported increases in the use of some practices for VAP such as semirecumbent positioning (89% [79 of 89] in 2005 vs 97% [61 of 63] in 2017, P = .007 for trend) and subglottic secretion drainage (23% [19 of 84] in 2005 vs 65% [40 of 62] in 2017, P < .001), use of other key practices such as daily interruptions of sedation (85% [55 of 65] in 2009 vs 87% [54 of 62] in 2017, P = .66) and early mobilization (81% [52 of 64] in 2013 vs 82% [51 of 62] in 2017, P = .88) has not increased. Antibiotic stewardship programs are now reported in nearly every VA hospital (97% [71 of 73]); however, some hospitals report practices for microbiologic testing for HAIs (eg, 22% [16 of 72] report routine urine culture testing in 2017) that could also contribute to antibiotic overuse.

CONCLUSIONS AND RELEVANCE

From 2005 to 2017, reported use of 12 different infection prevention practices increased in VA hospitals. Areas for continued improvement of infection prevention practices appear to include CAUTI, certain VAP practices, and diagnostic stewardship for HAI. The reported adoption of many infection prevention practices in VA hospitals was higher than in non-VA hospitals. As hospitals continue to merge and health systems become increasingly integrated, these successes could help inform patient safety broadly.

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.

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.

Patient Experiences with Clostridioides difficile Infection: Results of a Canada-Wide Survey

PURPOSE

Clostridioides difficile infection (CDI) is the most prevalent cause of nosocomial infectious diarrhea in Canada and is highly correlated with antibiotic use and contact with health care facilitates. The often-severe symptoms of CDI include diarrhea, dehydration, and abdominal pain. Patients often relapse following symptom resolution, resulting in increased morbidity. Previous research on the impact of CDI centered around the health-care system, clinician perspectives and economic burden, but not on patient experiences. The purpose of this study was to understand the impact of CDI on patients in Canada.

METHODS

The Gastrointestinal Society conducted online surveys and gathered data from 167 qualifying participants, who were either patients or their non-treating caregivers. Quantitative parameters were analyzed by descriptive and comparative statistics and contextualized with qualitative insights derived from thematic analysis of open-ended questions.

RESULTS

Our findings, which focused on clinical parameters such as prior exposure to health-care settings, antibiotic use, and patients' symptoms, mirrored findings from previous research. Interestingly, most surveyed respondents experienced delays in diagnosis and treatment; 29% waited 6-30 days and 10% over 30 days. This delayed diagnosis was further complicated by the report that 62% of respondents did not experience symptom resolution within 7 days of initiating treatment. Importantly, our results suggest a lasting impact after the resolution of CDI and we saw a reduction of self-assessed quality of life from prior to post CDI. Patients' priorities regarding their experience with CDI focused around concerns about the health-care system, particularly time to diagnosis and treatment, concerns about antibiotic usage and needs from health-care providers.

CONCLUSION

This is the first Canadian report on patients' experience with CDI. Our data highlight the symptom-related impact on patients and the long-lasting effect on the quality of life including emotional impact. Reducing time to diagnosis and improving patient education are important priorities to attenuate the impact on patients.

Clostridioides difficile nurse driven protocol: A cautionary tale

In a 12-month study, a nurse driven protocol was implemented at a tertiary academic medical center. The purpose of the nurse driven protocol was to identify community-onset Clostridioides difficile infections, expeditiously isolate patients with presumed C difficile diarrheal illness, and prevent transmission while simultaneously decreasing the incidence of hospital-onset C difficile. The overall adherence to fidelity of the protocol was poor and failed to have a significant impact on infection rates.

Risk factors for Clostridioides difficile infection and colonization among patients admitted to an intensive care unit in Shanghai, China

Background

Clostridioides difficile is considered the main pathogen responsible for hospital-acquired infections. This prospective study determined the prevalence, molecular epidemiological characteristics, and risk factors for C. difficile infection (CDI) and C. difficile colonization (CDC) among patients in the intensive care unit (ICU) of a large-scale tertiary hospital in China, with the aim of providing strategies for efficient CDI and CDC prevention and control.

Methods

Stool samples were collected and anaerobically cultured for C. difficile detection. The identified isolates were examined for toxin genes and subjected to multilocus sequence typing. Patients were classified into CDI, CDC, and control groups, and their medical records were analyzed to determine the risk factors for CDI and CDC.

Results

Of the 800 patients included in the study, 33 (4.12%) and 25 (3.12%) were identified to have CDI and CDC, respectively. Associations with CDI were found for fever (OR = 13.993), metabolic disorder (OR = 7.972), and treatment with fluoroquinolone (OR = 42.696) or combined antibiotics (OR = 2.856). CDC patients were characterized by prolonged hospital stay (OR = 1.137), increased number of comorbidities (OR = 36.509), respiratory diseases (OR = 0.043), and treatment with vancomycin (OR = 18.168). Notably, treatment with metronidazole was found to be a protective factor in both groups (CDI: OR = 0.042; CDC: OR = 0.013). Eighteen sequence types (STs) were identified. In the CDI group, the isolated strains were predominantly toxin A and toxin B positive (A + B+) and the epidemic clone was genotype ST2. In the CDC group, the dominant strains were A + B+ and the epidemic clone was ST81.

Conclusions

The prevalences of CDC and CDI in our ICU were relatively high, suggesting the importance of routine screening for acquisition of C. difficile. Future prevention and treatment strategies for CDC and CDI should consider hospital stay, enteral nutrition, underlying comorbidities, and use of combined antibiotics. Moreover, metronidazole may be a protective factor for both CDI and CDC, and could be used empirically.

Performance Evaluation of the Luminex Aries C. difficile Assay in Comparison to Two Other Molecular Assays within a Multihospital Health Care Center

Clostridioides difficile infection (CDI) remain a serious issue in the United States. Fast and accurate diagnosis of CDI is paramount to achieve immediate infection control initiation, triaging, and isolation, as well as appropriate antibiotic treatment. However, both, over- and underdiagnosis can lead to adverse patient outcomes, such as unnecessary administration of antibiotics or unwanted spread of spores in any hospital setting, respectively.

Clostridioides difficile infection (CDI) remain a serious issue in the United States. Fast and accurate diagnosis of CDI is paramount to achieve immediate infection control initiation, triaging, and isolation, as well as appropriate antibiotic treatment. However, both, over- and underdiagnosis can lead to adverse patient outcomes, such as unnecessary administration of antibiotics or unwanted spread of spores in any hospital setting, respectively. In this prospective study, we evaluated the FDA-cleared Aries C. difficile assay and compared its performance and workflow characteristics to those of the BD Max Cdiff and Xpert C. difficile/Epi assays. Out of 302 samples tested, 55 (18.2%) samples were positive, and 234 (77.5%) samples were negative for C. difficile by all three testing methods. Comparison results showed a positive and negative percent agreement (PPA and NPA, respectively) between the Aries and Xpert assays of 95.2% (59/62) and 99.2% (238/240), respectively. The PPA and NPA between the Aries and BD Max assays were 91.8% (56/61) and 96.6% (230/238), respectively. Invalid result rates were determined to be 2.6% for the BD Max assay, 1.0% for the Aries assay, and 0% for the Xpert assay. Hands-on time (HoT) and total turnaround time (TAT) varied considerably depending on the sample number and instrument throughput. The HoT ranged from 1.2 to 3.5 min per sample, and the TAT was 1 to 2.3 h. Overall, the results demonstrated that the Aries assay is a rapid and sensitive method for the diagnosis of CDI in clinical laboratories.

Epidemiologic Trends in Clostridioides difficile Infections in a Regional Community Hospital Network

IMPORTANCE

Clostridioides difficile infection (CDI) remains a leading cause of health care facility-associated infection. A greater understanding of the regional epidemiologic profile of CDI could inform targeted prevention strategies.

OBJECTIVES

To assess trends in incidence of health care facility-associated and community-acquired CDI among hospitalized patients over time and to conduct a subanalysis of trends in the NAP1 strain of CDI over time.

DESIGN, SETTING, AND PARTICIPANTS

This long-term multicenter cohort study reviewed records of patients (N = 2 025 678) admitted to a network of 43 regional community hospitals primarily in the southeastern United States from January 1, 2013, through December 31, 2017. Generalized linear mixed-effects models were used to adjust for potential clustering within facilities and changing test method (nucleic acid amplification testing or toxin enzyme immunoassay) over time.

MAIN OUTCOMES AND MEASURES

Clostridioides difficile infection incidence rates were counted as cases per 1000 admissions for community-acquired and total CDI cases or cases per 10 000 patient-days for health care facility-associated CDI. Long-term trends in the proportion of cases acquired in the community and in NAP1 strain incidence were also evaluated.

RESULTS

A total of 2 025 678 admissions and 21 254 CDI cases were included (12 678 [59.6%] female; median [interquartile range] age, 69 [55-80] years). Median (interquartile range) total CDI incidence increased slightly from 7.9 (3.5-12.4) cases per 1000 admissions in 2013 to 9.3 (4.9-13.7) cases per 1000 admissions in 2017. After adjustment, the overall incidence of health care facility-associated CDI declined (incidence rate ratio [IRR], 0.995; 95% CI, 0.990-0.999; P = .03), whereas insufficient evidence was found for either an increase or a decrease in community-acquired CDI (IRR, 1.004; 95% CI, 0.999-1.009; P = .14). The proportion of cases classified as community acquired increased over time from a mean (SD) of 0.49 (0.28) in 2013 to 0.61 (0.26) in 2017 (odds ratio, 1.010 per month; 95% CI, 1.006-1.015; P < .001). Rates of the NAP1 strain of CDI varied widely between facilities, with no statistically significant change in NAP1 strain incidence over time in the community setting (IRR, 1.007; 95% CI, 0.994-1.021) or health care facility setting (IRR, 1.011; 95% CI, 0.990-1.032).

CONCLUSIONS AND RELEVANCE

The findings suggest that, despite the modest improvement in health care facility-associated CDI rates, a better understanding of community-acquired CDI incidence is needed for future infection prevention efforts.

Quality assurance for genotyping and resistance testing of Clostridium (Clostridioides) difficile isolates - Experiences from the first inter-laboratory ring trial in four German speaking countries

Clostridium (Clostridioides) difficile is a major cause of nosocomial diarrhoea. A first inter-laboratory ring trial was performed in four European countries to evaluate the genotyping and antibiotic susceptibility testing (AST) accuracy. Six C. difficile isolates representing the epidemiologic important ribotypes (RT), RT001, RT002, RT010, RT014, RT027, and RT078 were blinded and send to 21 participating laboratories. Participants tested the samples with their genotyping and AST methods in use for concordance with reference. A total of 21 genotyping- and 14 antimicrobial susceptibility data sets were obtained. Ribotyping (11 participants) correctly identified most RTs (median 91% concordance rate) except for RT002, which was misidentified in 4/11 reports. However, this isolate was correctly asserted to RT002 after an update of a publicly available ribotyping database. Multilocus sequence typing, surface layer sequence typing, DNA microarray based genotyping, and whole genome sequencing, which were used by 1-3 participants, identified all six isolates correctly. AST was done by epsilometry by the participants and compared to agar dilution data determined by the coordinating reference centre. Susceptibilities against metronidazole, moxifloxacin, and vancomycin were correctly identified in 235 of 237 cases and in accordance to agar dilution as the gold standard. Genotyping of the C. difficile test strains revealed a remarkable high concordance on the level of ribotypes with a wide variety of methods. Epsilometry appears to be a reliable method for AST of C. difficile isolates in routine clinical microbiology laboratories.

Influence of Diagnostic Method on Outcomes in Phase 3 Clinical Trials of Bezlotoxumab for the Prevention of Recurrent Clostridioides difficile Infection: A Post Hoc Analysis of MODIFY I/II

Background

The optimum diagnostic test method for Clostridioides difficile infection (CDI) remains controversial due to variation in accuracy in identifying true CDI. This post hoc analysis examined the impact of CDI diagnostic testing methodology on efficacy outcomes in phase 3 MODIFY I/II trials.

Methods

In MODIFY I/II (NCT01241552/NCT01513239), participants received bezlotoxumab (10 mg/kg) or placebo during anti-CDI treatment for primary/recurrent CDI (rCDI). Using MODIFY I/II pooled data, initial clinical cure (ICC) and rCDI were assessed in participants diagnosed at baseline using direct detection methods (enzyme immunoassay [EIA]/cell cytotoxicity assay [CCA]) or indirect methods to determine toxin-producing ability (toxin gene polymerase chain reaction [tgPCR]/toxigenic culture).

Results

Of 1554 participants who received bezlotoxumab or placebo in MODIFY I/II, 781 (50.3%) and 773 (49.7%) were diagnosed by tgPCR/toxigenic culture and toxin EIA/CCA, respectively. Participants diagnosed by toxin EIA/CCA were more likely to be inpatients, older, and have severe CDI. In bezlotoxumab recipients, ICC rates were slightly higher in the toxin EIA/CCA subgroup (81.7%) vs tgPCR/toxigenic culture (78.4%). Bezlotoxumab significantly reduced the rCDI rate vs placebo in both subgroups; however, the magnitude of reduction was substantially larger in participants diagnosed by toxin EIA/CCA (relative difference, –46.6%) vs tgPCR/toxigenic culture (–29.1%). In bezlotoxumab recipients, the rCDI rate was lower in the toxin EIA/CCA subgroup (17.6%) vs tgPCR/toxigenic culture (23.6%; absolute difference, –6.0%; 95% confidence interval, –12.4 to 0.3; relative difference, –25.4%).

Conclusions

Diagnostic tests that detect fecal C. difficile toxins are of fundamental importance to accurately diagnosing CDI, including in clinical trial design, ensuring that therapeutic efficacy is not underestimated.

Attributable costs and length of stay of hospital-acquired Clostridioides difficile: A population-based matched cohort study in Alberta, Canada

OBJECTIVE

To determine the attributable cost and length of stay of hospital-acquired Clostridioides difficile infection (HA-CDI) from the healthcare payer perspective using linked clinical, administrative, and microcosting data.

DESIGN

A retrospective, population-based, propensity-score-matched cohort study.

SETTING

Acute-care facilities in Alberta, Canada.

PATIENTS

Admitted adult (≥18 years) patients with incident HA-CDI and without CDI between April 1, 2012, and March 31, 2016.

METHODS

Incident cases of HA-CDI were identified using a clinical surveillance definition. Cases were matched to noncases of CDI (those without a positive C. difficile test or without clinical CDI) on propensity score and exposure time. The outcomes were attributable costs and length of stay of the hospitalization where the CDI was identified. Costs were expressed in 2018 Canadian dollars.

RESULTS

Of the 2,916 HA-CDI cases at facilities with microcosting data available, 98.4% were matched to 13,024 noncases of CDI. The total adjusted cost among HA-CDI cases was 27% greater than noncases of CDI (ratio, 1.27; 95% confidence interval [CI], 1.21-1.33). The mean attributable cost was $18,386 (CAD 2018; USD $14,190; 95% CI, $14,312-$22,460; USD $11,046-$17,334). The adjusted length of stay among HA-CDI cases was 13% greater than for noncases of CDI (ratio, 1.13; 95% CI, 1.07-1.19), which corresponds to an extra 5.6 days (95% CI, 3.10-8.06) in length of hospital stay per HA-CDI case.

CONCLUSIONS

In this population-based, propensity score matched analysis using microcosting data, HA-CDI was associated with substantial attributable cost.

Fifteen-minute consultation on the healthy child: Bowel habit in infants and children

A common presentation to the general paediatric clinic is a child or young person's difficult bowel habit, which is often a potent source of anxiety for parents and carers. A large proportion of these children will have a functional cause for their symptoms, with unnecessary investigation and non-evidence-based treatments adding to their difficulties. This article aims to explain what encompasses the normal bowel habit in children and young people, reassure where appropriate and identify those patterns that may be suggestive of a disorder or disease requiring treatment. We illustrate both extremes of the spectrum of normal bowel habit in children with two case studies.

A national survey of testing and management of asymptomatic carriage of C. difficile

A nationwide survey indicated that screening for asymptomatic carriers of C. difficile is an uncommon practice in US healthcare settings. Better understanding of the role of asymptomatic carriage in C. difficile transmission, and of the measures available to reduce that risk, are needed to inform best practices regarding the management of carriers.

Resistance diagnostics as a public health tool to combat antibiotic resistance: A model-based evaluation

Rapid point-of-care resistance diagnostics (POC-RD) are a key tool in the fight against antibiotic resistance. By tailoring drug choice to infection genotype, doctors can improve treatment efficacy while limiting costs of inappropriate antibiotic prescription. Here, we combine epidemiological theory and data to assess the potential of resistance diagnostics (RD) innovations in a public health context, as a means to limit or even reverse selection for antibiotic resistance. POC-RD can be used to impose a nonbiological fitness cost on resistant strains by enabling diagnostic-informed treatment and targeted interventions that reduce resistant strains' opportunities for transmission. We assess this diagnostic-imposed fitness cost in the context of a spectrum of bacterial population biologies and find that POC-RD have a greater potential against obligate pathogens than opportunistic pathogens already subject to selection under "bystander" antibiotic exposure during asymptomatic carriage (e.g., the pneumococcus). We close by generalizing the notion of RD-informed strategies to incorporate carriage surveillance information and illustrate that coupling transmission-control interventions to the discovery of resistant strains in carriage can potentially select against resistance in a broad range of opportunistic pathogens.

Pediatric oncology and stem cell transplant patients with healthcare-associated Clostridium difficile infection were already colonized on admission

Clostridium difficile is the leading cause of healthcare-associated infections worldwide. The diagnosis of C. difficile infection (CDI) in pediatric oncology patients is complex as diarrhea is common, and there is a high rate of colonization in infants and young children. This study was conducted to assess the accuracy of the surveillance definitions of healthcare-associated CDI (HA-CDI) and to determine the prevalence of toxigenic C. difficile colonization among pediatric oncology and stem cell transplant patients.

METHODS

A prospective cohort study was conducted over a three-year period in an inpatient pediatric oncology and stem cell transplant setting. Baseline stool samples were collected within three days of admission and were genotypically compared with clinically indicated samples submitted after three days of admission.

RESULTS

A total of 175 patients were recruited with a total of 536 admissions. The adjusted prevalence of baseline toxigenic C. difficile colonization among admissions was 32.8%. Seventy-eight percent of positive admissions did not have history of CDI. Colonization with a toxigenic strain on admission was predictive of CDI (OR = 28.6; 95% CI, 6.58-124.39; P < 0.001). Nearly all clinical isolates (8/9) shared identical pulsed-field gel electrophoresis patterns with baseline isolates or were closely related (1/9). Only one of the 11 cases that were considered HA-CDI was potentially nosocomially acquired.

CONCLUSION

The prevalence of colonization with toxigenic C. difficile in our cohort is high. Unfortunately, the current CDI surveillance definitions overestimate the incidence of HA-CDI in pediatric oncology and stem cell transplantation settings.

Consensus on the prevention, diagnosis, and treatment of Clostridium difficile infection

In recent decades, Clostridium difficile infection (CDI) has become a worldwide health problem. Mexico is no exception, and therefore the Asociación Mexicana de Gastroenterología brought together a multidisciplinary group (gastroenterologists, endoscopists, internists, infectious disease specialists, and microbiologists) to carry out the "Consensus on the prevention, diagnosis, and treatment of Clostridium difficile infection", establishing useful recommendations (in relation to the adult population) for the medical community. Said recommendations are presented herein. Among them, it was recognized that CDI should be suspected in subjects with diarrhea that have a history of antibiotic and/or immunosuppressant use, but that it can also be a community-acquired infection. A 2-step diagnostic algorithm was proposed, in which a highly sensitive test, such as glutamate dehydrogenase (GDH), is first utilized, and if positive, confirmed by the detection of toxins through immunoassay or nucleic acid detection tests. Another recommendation was that CDI based on clinical evaluation be categorized as mild-moderate, severe, and complicated severe, given that such a classification enables better therapeutic decisions to be made. In mild-moderate CDI, oral vancomycin is the medication of choice, and metronidazole is recommended as an alternative treatment. In addition, fecal microbiota transplantation was recognized as an efficacious option in patients with recurrence or in the more severe cases of infection, and surgery should be reserved for patients with severe colitis (toxic megacolon), in whom all medical treatment has failed.

Laboratory comparison between cell cytotoxicity neutralization assay and ultrasensitive single molecule counting technology for detection of Clostridioides difficile toxins A and B, PCR, enzyme immunoassays, and multistep algorithms

Diagnostic tests for Clostridioides difficile infection (CDI) lack either specificity (nucleic acid amplification tests) or sensitivity (enzyme immunoassays; EIAs). The performance of the Singulex Clarity® C. diff toxins A/B assay was compared to cell cytotoxicity neutralization assay. Testing was also performed using an EIA for glutamate dehydrogenase (GDH) and C. difficile toxins A and B (C. Diff Quik Chek Complete®), polymerase chain reaction (PCR) (BD MAX™ Cdiff Assay), and 2 multistep algorithms: algorithm 1 (discordant GDH/toxin results arbitrated by PCR) and algorithm 2 (PCR-positive samples tested with toxin EIA). The Clarity assay and PCR both had 97% sensitivity, while specificity was 100% for Clarity and 79% for PCR. Algorithm 1 yielded 41% discordant results, and both toxin EIA and algorithm 2 had 58% sensitivity. Median toxin concentrations, as measured by the Clarity C. difficile toxin assay, were 3590, 11.5, 0.4, and 0 pg/mL for GDH+/toxin+, GDH+/toxin-/PCR+, GDH+/toxin-/PCR-, and GDH-/toxin- samples, respectively (P < 0.001). The Clarity assay may offer a single-test solution for CDI.

Seasonality and community interventions in a mathematical model of Clostridium difficile transmission

BACKGROUND

Clostridium difficile infection (CDI) is the leading cause of antibiotic-associated diarrhoea with peak incidence in late winter or early autumn. Although CDI is commonly associated with hospitals, community transmission is important.

AIM

To explore potential drivers of CDI seasonality and the effect of community-based interventions to reduce transmission.

METHODS

A mechanistic compartmental model of C. difficile transmission in a hospital and surrounding community was used to determine the effect of reducing transmission or antibiotic prescriptions in these settings. The model was extended to allow for seasonal antibiotic prescriptions and seasonal transmission.

FINDINGS

Modelling antibiotic seasonality reproduced the seasonality of CDI, including approximate magnitude (13.9-15.1% above annual mean) and timing of peaks (0.7-1.0 months after peak antibiotics). Halving seasonal excess prescriptions reduced the incidence of CDI by 6-18%. Seasonal transmission produced larger seasonal peaks in the prevalence of community colonization (14.8-22.1% above mean) than seasonal antibiotic prescriptions (0.2-1.7% above mean). Reducing transmission from symptomatic or hospitalized patients had little effect on community-acquired CDI, but reducing transmission in the community by ≥7% or transmission from infants by ≥30% eliminated the pathogen. Reducing antibiotic prescription rates led to approximately proportional reductions in infections, but limited reductions in the prevalence of colonization.

CONCLUSION

Seasonal variation in antibiotic prescription rates can account for the observed magnitude and timing of C. difficile seasonality. Even complete prevention of transmission from hospitalized patients or symptomatic patients cannot eliminate the pathogen, but interventions to reduce transmission from community residents or infants could have a large impact on both hospital- and community-acquired infections.

Single centre clinical experience with fidaxomicin in the treatment of Clostridium difficile infection in Slovakia

OBJECTIVE

Clostridium difficile infection (CDI) has become one of the most common causes of hospital-acquired infections. Fidaxomicin is one of the latest antibiotics used in the treatment of CDI, however, treatment cost affects recommendations for its use in several countries. We have analysed the treatment of our patients with CDI, treated by fidaxomicin since it was introduced to the market in 2018 and became available in the second biggest Slovak hospital, University Hospital of L. Pasteur. Our aim was to determine efficacy and safety of fidaxomicin in the treatment of CDI in Slovak patients.

METHODS

We reviewed all courses of fidaxomicin use in our hospital (n = 60). Fidaxomicin was used for first recurrence (12 times), second recurrence (4 times), third recurrence (2 times), and fifth recurrence (1 patient). 41 patients received fidaxomicin first-line.

RESULTS

Success of fidaxomicin treatment was recorded at 86.7% within the whole cohort. In the recurrent Clostridium difficile infection (rCDI) subgroup, fidaxomicin was 63% effective with three patients dying (15.7%) and two patients developing subsequent rCDI. During the duration of the study, 6 patients in total died. Only one of three patients, with three or more recurrences of CDI, had no further presentations after eight weeks of completion of treatment.

CONCLUSIONS

The biggest benefit from fidaxomicin treatment was shown in a cohort of patients with primary CDI infection demonstrating a low recurrence rate and significant reduction of fidaxomicin effectiveness in preventing a recurrence when treating patients with multiple rCDI.

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.

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.