Predictors of asymptomatic Clostridium difficile colonization on hospital admission

Environmental approaches to controlling Clostridioides difficile infection in healthcare settings

As today's most prevalent and costly healthcare-associated infection, hospital-onset Clostridioides difficile infection (HO-CDI) represents a major threat to patient safety world-wide. This review will discuss how new insights into the epidemiology of CDI have quantified the prevalence of C. difficile (CD) spore contamination of the patient-zone as well as the role of asymptomatically colonized patients who unavoidable contaminate their near and distant environments with resilient spores. Clarification of the epidemiology of CD in parallel with the development of a new generation of sporicidal agents which can be used on a daily basis without damaging surfaces, equipment, or the environment, led to the research discussed in this review. These advances underscore the potential for significantly mitigating HO-CDI when combined with ongoing programs for optimizing the thoroughness of cleaning as well as disinfection. The consequence of this paradigm-shift in environmental hygiene practice, particularly when combined with advances in hand hygiene practice, has the potential for significantly improving patient safety in hospitals globally by mitigating the acquisition of CD spores and, quite plausibly, other environmentally transmitted healthcare-associated pathogens.

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

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

American Society for Transplantation and Cellular Therapy Series: #5-Management of Clostridioides difficile Infection in Hematopoietic Cell Transplant Recipients

The Practice Guidelines Committee of the American Society for Transplantation and Cellular Therapy partnered with its Transplant Infectious Disease Special Interest Group to update its 2009 compendium-style infectious disease guidelines for hematopoietic cell transplantation (HCT). A completely new approach was taken with the goal of better serving clinical providers by publishing each standalone topic in the infectious disease series as a concise format of frequently asked questions (FAQ), tables, and figures. Adult and pediatric infectious disease and HCT content experts developed and then answered FAQs and finalized topics with harmonized recommendations that were made by assigning an A through E strength of recommendation paired with a level of supporting evidence graded I through III. This fifth guideline in the series focuses on Clostridioides difficile infection with FAQs that address the prevalence, incidence, clinical features, colonization versus infection, clinical complications, diagnostic considerations, pharmacological therapies for episodic or recurrent infection, and the roles of prophylactic antibiotics, probiotics, and fecal microbiota transplantation.

Oxidative ornithine metabolism supports non-inflammatory C. difficile colonization

The enteric pathogen Clostridioides difficile (Cd) is responsible for a toxin-mediated infection that causes more than 200,000 recorded hospitalizations and 13,000 deaths in the United States every year1. However, Cd can colonize the gut in the absence of disease symptoms. Prevalence of asymptomatic colonization by toxigenic Cd in healthy populations is high; asymptomatic carriers are at increased risk of infection compared to noncolonized individuals and may be a reservoir for transmission of Cd infection2,3. Elucidating the molecular mechanisms by which Cd persists in the absence of disease is necessary for understanding pathogenesis and developing refined therapeutic strategies. Here, we show with gut microbiome metatranscriptomic analysis that mice recalcitrant to Cd infection and inflammation exhibit increased community-wide expression of arginine and ornithine metabolic pathways. To query Cd metabolism specifically, we leverage RNA sequencing in gnotobiotic mice infected with two wild-type strains (630 and R20291) and isogenic toxin-deficient mutants of these strains to differentiate inflammation-dependent versus -independent transcriptional states. A single operon encoding oxidative ornithine degradation is consistently upregulated across non-toxigenic Cd strains. Combining untargeted and targeted metabolomics with bacterial and host genetics, we demonstrate that both diet- and host-derived sources of ornithine provide a competitive advantage to Cd, suggesting a mechanism for Cd persistence within a non-inflammatory, healthy gut.

Pediatric Fecal Microbiota Transplantation in Recurrent Clostridioides Difficile

With the rising rates of Clostridioides (Clostridium) difficile infection (CDI) in children, recognizing the limitations of CDI-directed antibiotic therapy, especially in recurrent CDI (rCDI), is important. Fecal microbiota transplantation (FMT), which directly targets the underlying gut dysbiosis present in rCDI, is an important treatment option to consider in rCDI. This article will summarize indications, procedures, effectiveness, and the safety of FMT for rCDI in pediatric patients. [Pediatr Ann. 2021;50(12):e515-e521.].

Health Care Environmental Hygiene: New Insights and Centers for Disease Control and Prevention Guidance

Recent research has significantly clarified the impact of optimizing patient-zone environmental hygiene. New insights into the environmental microbial epidemiology of many hospital-associated pathogens, especially Clostridioides difficile, have clarified and quantified the role of ongoing occult pathogen transmission from the near-patient environment. The recent development of safe, broadly effective surface chemical disinfectants has led to new opportunities to broadly enhance environmental hygiene in all health care settings. The Centers for Disease Control and Prevention has recently developed a detailed guidance to assist all health care settings in implementing optimized programs to mitigate health care-associated pathogen transmission from the near-patient surfaces.

Level of Knowledge of Medical Staff on the Basis of the Survey in Terms of Risk Management, Associated with Clostridioides difficile Infections

Infections caused by the toxigenic strains of Clostridioides difficile in the hospital environment pose a serious public health problem. The progressive increase in hospital infections in Poland indicates that risk management is a tool that is not used in an effective way and significantly differs from the goals set by the Leading Authorities, the Ministry of Health and its subordinate units. Systematic education of medical personnel constitutes the basic element of rational risk management aimed at reducing the number of infections as it allows for the transfer of knowledge, development of appropriate organizational procedures, and improves internal communication. This paper presents the results of a survey conducted in hospital facilities throughout Poland. The study dealt with what medical personnel know about channels of transmission and prevention of Clostridioides difficile infections in the hospital setting, professional training and risk management in terms of reducing the number of infections. The survey reveals that Clostridioides difficile continues to be a serious problem in the inpatient care system. Procedures and management strategies implemented by hospitals in order to limit the spread of the pathogen are predominantly focused on short-term action, which does not lead to a real improvement in terms of hospitalized patients' safety. The infection risk management system was assessed at a fairly low level. The obtained research results confirmed the research hypotheses that had been formulated.

Clostridioides difficile Whole-genome Sequencing Differentiates Relapse With the Same Strain From Reinfection With a New Strain

BACKGROUND

Current approaches in tracking Clostridioides difficile infection (CDI) and individualizing patient management are incompletely defined.

METHODS

We recruited 468 subjects with CDI at Mayo Clinic Rochester between May and December 2016 and performed whole-genome sequencing (WGS) on C. difficile isolates from 397. WGS was also performed on isolates from a subset of the subjects at the time of a recurrence of infection. The sequence data were analyzed by determining core genome multilocus sequence type (cgMLST), with isolates grouped by allelic differences and the predicted ribotype.

RESULTS

There were no correlations between C. difficile isolates based either on cgMLST or ribotype groupings and CDI outcome. An epidemiologic assessment of hospitalized subjects harboring C. difficile isolates with ≤2 allelic differences, based on standard infection prevention and control assessment, revealed no evidence of person-to-person transmission. Interestingly, community-acquired CDI subjects in 40% of groups with ≤2 allelic differences resided within the same zip code. Among 18 subjects clinically classified as having recurrent CDI, WGS revealed 14 with initial and subsequent isolates differing by ≤2 allelic differences, suggesting a relapse of infection with the same initial strain, and 4 with isolates differing by >50 allelic differences, suggesting reinfection. Among the 5 subjects classified as having a reinfection based on the timing of recurrence, 3 had isolates with ≤2 allelic differences between them, suggesting a relapse, and 2 had isolates differing by >50 allelic differences, suggesting reinfection.

CONCLUSIONS

Our findings point to potential transmission of C. difficile in the community. WGS better differentiates relapse from reinfection than do definitions based on the timing of recurrence.

Novel Detection of Nasty Bugs, Prevention Is Better than Cure

Hospital-acquired infections (HAIs) are a growing concern around the world. They contribute to increasing mortality and morbidity rates and are an economic threat. All hospital patients have the potential to contract an HAI, but those with weakened or inferior immune systems are at highest risk. Most hospital patients will contract at least one HAI, but many will contract multiple ones. Bacteria are the most common cause of HAIs and contribute to 80-90% of all HAIs, with Staphylococcus aureus, Clostridium difficile, Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae accounting for the majority. Each of these bacteria are highly resistant to antibiotics and can produce a protective film, known as a biofilm, to further prevent their eradication. It has been shown that by detecting and eradicating bacteria in the environment, infection rates can be reduced. The current methods for detecting bacteria are time consuming, non-specific, and prone to false negatives or false positives. Aptamer-based biosensors have demonstrated specific, time-efficient and simple detection, highlighting the likelihood that they could be used in a similar way to detect HAI-causing bacteria.

Optimization of an Assay To Determine Colonization Resistance to Clostridioides difficile in Fecal Samples from Healthy Subjects and Those Treated with Antibiotics

A healthy, intact gut microbiota is often resistant to colonization by gastrointestinal pathogens. During periods of dysbiosis, however, organisms such as Clostridioides difficile can thrive. We describe an optimized in vitro colonization resistance assay for C. difficile in stool (CRACS) and demonstrate the utility of this assay by assessing changes in colonization resistance following antibiotic exposure. Fecal samples were obtained from healthy volunteers (n = 6) and from healthy subjects receiving 5 days of moxifloxacin (n = 11) or no antibiotics (n = 10). Samples were separated and either not manipulated (raw) or sterilized (autoclaved or filtered) prior to inoculation with C. difficile ribotype 027 spores and anaerobic incubation for 72 h. Different methods of storing fecal samples were also investigated in order to optimize the CRACS. In healthy, raw fecal samples, incubation with spores did not lead to increased C. difficile total viable counts (TVCs) or cytotoxin detection. In contrast, increased C. difficile TVCs and cytotoxin detection occurred in sterilized healthy fecal samples or those from antibiotic-treated individuals. The CRACS was functional with fecal samples stored at either 4°C or -80°C but not with those stored with glycerol (12% or 30% [vol/vol]). Our data show that the CRACS successfully models in vitro the loss of colonization resistance and subsequent C. difficile proliferation and toxin production. The CRACS could be used as a proxy for C. difficile infection in clinical studies or to determine if an individual is at risk of developing C. difficile infection or other potential infections occurring due to a loss of colonization resistance.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Longitudinal investigation of carriage rates and genotypes of toxigenic Clostridium difficile in hepatic cirrhosis patients

Toxigenic Clostridium difficile (C. difficile) carriers represent an important source in the transmission of C. difficile infection (CDI) during hospitalisation, but its prevalence and mode in patients with hepatic cirrhosis are not well established. We investigated longitudinal changes in carriage rates and strain types of toxigenic C. difficile from admission to discharge among hepatic cirrhosis patients. Toxigenic C. difficile was detected in 104 (19.8%) of 526 hepatic cirrhosis patients on admission, and the carriage status changed in a portion of patients during hospitalisation. Approximately 56% (58/104) of patients lost the colonisation during their hospital stay. Among the remaining 48 patients who remained positive for toxigenic C. difficile, the numbers of patients who were positive at one, two, three and four isolations were 10 (55.6%), three (16.7%), two (11.1%) and three (16.7%), respectively. Twenty-eight patients retained a particular monophyletic strain at multiple isolations. The genotype most frequently identified was the same as that frequently identified in symptomatic CDI patients. A total of 25% (26/104) of patients were diagnosed with CDI during their hospital stay. Conclusions: Colonisation with toxigenic C. difficile strains occurs frequently in cirrhosis patients and is a risk factor for CDI.

Cytoskeletal Tropomyosin as a Biomarker in Clostridium difficile Infection

Background

Current diagnostics of Clostridium difficile infection (CDI) heavily relies on detection of the disease-causing organism. The objective of this study was to investigate a cytoskeletal protein, tropomyosin (Tpm), as a CDI biomarker.

Methods

Fecal Tpm was tested by monoclonal antibodies (mAbs) in a 12-month prospective study. Remnant diarrheal clinical specimens and relevant clinical data were collected. The CDI positive (CDI⁺, n = 230) and CDI negative (CDI^-, n = 228) groups were composed of samples testing positive or negative by polymerase chain reaction (PCR) (Xpert^® C. difficile/Epi, Cepheid), respectively. The other enteric pathogen (OEP) group (n = 52) was composed of specimens tested for the presence of other enteric pathogens or parasites by routine testing methods. Extracted fecal Tpm was detected by Western blot and the results were correlated with CDI based on clinical and microbiology laboratory data.

Results

A total of 510 stool specimens were tested. Tpm is not stable in stool, suggesting the utility of fresh specimens. In the CDI⁺ group, specificity and sensitivity of Tpm detection in correlation with a CDI were 93.2% and 53.7%, respectively, when only "true CDI" and "not CDI" were analyzed (110 samples). For CDI⁺ samples, 23% did not satisfy CDI clinical signs. Tpm positives in the CDI^- group (8.3%) had inflammatory bowel diseases.

Conclusion

Tpm has a potential role as a CDI biomarker in combination with C. difficile PCR and an appropriate clinical evaluation. However, non-muscle Tpm, as a biomarker for CDI, suffers from a low sensitivity in our study. Therefore further investigation using larger cohorts is needed.

Clostridium difficile - From Colonization to Infection

Clostridium difficile is the most frequent cause of nosocomial antibiotic-associated diarrhea. The incidence of C. difficile infection (CDI) has been rising worldwide with subsequent increases in morbidity, mortality, and health care costs. Asymptomatic colonization with C. difficile is common and a high prevalence has been found in specific cohorts, e.g., hospitalized patients, adults in nursing homes and in infants. However, the risk of infection with C. difficile differs significantly between these cohorts. While CDI is a clear indication for therapy, colonization with C. difficile is not believed to be a direct precursor for CDI and therefore does not require treatment. Antibiotic therapy causes alterations of the intestinal microbial composition, enabling C. difficile colonization and consecutive toxin production leading to disruption of the colonic epithelial cells. Clinical symptoms of CDI range from mild diarrhea to potentially life-threatening conditions like pseudomembranous colitis or toxic megacolon. While antibiotics are still the treatment of choice for CDI, new therapies have emerged in recent years such as antibodies against C. difficile toxin B and fecal microbial transfer (FMT). This specific therapy for CDI underscores the role of the indigenous bacterial composition in the prevention of the disease in healthy individuals and its role in the pathogenesis after alteration by antibiotic treatment. In addition to the pathogenesis of CDI, this review focuses on the colonization of C. difficile in the human gut and factors promoting CDI.

Understanding Clostridium difficile Colonization

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

Clostridium difficile - From Colonization to Infection

Clostridium difficile is the most frequent cause of nosocomial antibiotic-associated diarrhea. The incidence of C. difficile infection (CDI) has been rising worldwide with subsequent increases in morbidity, mortality, and health care costs. Asymptomatic colonization with C. difficile is common and a high prevalence has been found in specific cohorts, e.g., hospitalized patients, adults in nursing homes and in infants. However, the risk of infection with C. difficile differs significantly between these cohorts. While CDI is a clear indication for therapy, colonization with C. difficile is not believed to be a direct precursor for CDI and therefore does not require treatment. Antibiotic therapy causes alterations of the intestinal microbial composition, enabling C. difficile colonization and consecutive toxin production leading to disruption of the colonic epithelial cells. Clinical symptoms of CDI range from mild diarrhea to potentially life-threatening conditions like pseudomembranous colitis or toxic megacolon. While antibiotics are still the treatment of choice for CDI, new therapies have emerged in recent years such as antibodies against C. difficile toxin B and fecal microbial transfer (FMT). This specific therapy for CDI underscores the role of the indigenous bacterial composition in the prevention of the disease in healthy individuals and its role in the pathogenesis after alteration by antibiotic treatment. In addition to the pathogenesis of CDI, this review focuses on the colonization of C. difficile in the human gut and factors promoting CDI.

When omeprazole met with asymptomatic Clostridium difficile colonization in a postoperative colon cancer patient: A case report

RATIONALE

Clostridium difficile infection (CDI) is a symptomatic infection due to the spore-forming bacterium, C. difficile. Asymptomatic C. difficile colonization is the stage in absence of symptoms, with a prevalence of 1.4% to 21% on hospital admission. Proton-pump inhibitors (PPIs) was implicated as a novel potential contributor to CDI. PPIs injection could make asymptomatic C. difficile colonization progress to C. difficile associated diarrhea (CDAD).

PATIENT CONCERNS

A postoperative colon cancer patient, who had been taking omeprazole for 4 years after operation, got asymptomatic C. difficile colonization. When he developed clinical symptoms of digestive tract, tumor recurrence was first suspected and intravenous omeprazole was prescribed, which ultimately led to progression to symptomatic CDI. In this report, we tell the confusing differential diagnosis of cancer-associated diseases and CDAD, and discuss the possibility of solving the PPIs overuse problem by making clinical pathway of PPIs use in Chinese hospitals.

DIAGNOSES

CDAD, incomplete intestinal obstruction, postoperation of colon cancer.

INTERVENTION

Electrolyte replacement and rehydration. Parenteral nutrition support. Omeprazole was prescribed but withdrawn later, and oral vancomycin was given at a dose of 0.25 g 4 times per day for 10 days.

OUTCOMES

Diarrhea was resolved, so long as the acid reflux and vomiting.

LESSONS

We have 2 lessons here: Be aware of PPIs induced CDI, especially the asymptomatic C. difficile colonization. Making clinical pathway specified on PPIs use by pharmacists could be a practical way to solve the problem of PPIs overuse.

Clinical Practice and Infrastructure Review of Fecal Microbiota Transplantation for Clostridium difficile Infection

A substantial proportion of Clostridium difficile infection (CDI) cases recur after completion of antibiotic therapy, and antibiotic cure rates diminish with each recurrence of CDI. Fecal microbiota transplantation (FMT) is an effective therapy for recurrent FMT, which otherwise requires prolonged or indefinite antibiotic treatment. FMT is performed by introducing the fecal microbial community obtained from a healthy donor or pool of donors into the stomach, small intestine, or colon of a patient with CDI. Multiple clinical trials support the usefulness of FMT in treating recurrent CDI, and CDI treatment guidelines now include consideration of FMT at the third CDI recurrence. However, there remain challenges to incorporating FMT into clinical practice. First, methods of fecal bacterial community processing vary, as do methods of FMT administration. Second, the optimal dosing strategy and expected benefit of FMT for refractory CDI, particularly for severe and severe complicated cases, are uncertain. Third, the US Food and Drug Administration (FDA) considers FMT an investigational treatment. Fourth, insurance reimbursement for FMT usually falls short of FMT administration costs. In the setting of rising C difficile incidence and growing evidence for FMT efficacy, the demand for FMT has increased. However, uncertainty surrounding optimal FMT preparation and administration methods, FDA oversight, and insurance reimbursement presently limits the clinical practice of FMT.

Toxigenic Clostridium difficile colonization among hospitalised adults; risk factors and impact on survival

OBJECTIVES

To establish risk factors for Clostridium difficile colonization among hospitalized patients in England.

METHODS

Patients admitted to elderly medicine wards at three acute hospitals in England were recruited to a prospective observational study. Participants were asked to provide a stool sample as soon as possible after enrolment and then weekly during their hospital stay. Samples were cultured for C. difficile before ribotyping and toxin detection by PCR. A multivariable logistic regression model of risk factors for C. difficile colonization was fitted from univariable risk factors significant at the p < 0.05 level.

RESULTS

410/727 participants submitted ≥1 stool sample and 40 (9.8%) carried toxigenic C. difficile in the first sample taken. Ribotype 106 was identified three times and seven other ribotypes twice. No ribotype 027 strains were identified. Independent predictors of colonization were previous C. difficile infection (OR 4.53 (95% C.I. 1.33-15.48) and malnutrition (MUST score ≥2) (OR 3.29 (95% C.I. 1.47-7.35)). Although C. difficile colonised patients experienced higher 90-day mortality, colonization was not an independent risk for death.

CONCLUSIONS

In a non-epidemic setting patients who have previously had CDI and have a MUST score of ≥2 are at increased risk of C. difficile colonization and could be targeted for active surveillance to prevent C. difficile transmission.

Australasian Society of Infectious Diseases updated guidelines for the management of Clostridium difficile infection in adults and children in Australia and New Zealand

The incidence of Clostridium difficile infection (CDI) continues to rise, whilst treatment remains problematic due to recurrent, refractory and potentially severe nature of disease. The treatment of C. difficile is a challenge for community and hospital-based clinicians. With the advent of an expanding therapeutic arsenal against C. difficile since the last published Australasian guidelines, an update on CDI treatment recommendations for Australasian clinicians was required. On behalf of the Australasian Society of Infectious Diseases, we present the updated guidelines for the management of CDI in adults and children.

Asymptomatic Clostridium difficile colonization in two Australian tertiary hospitals, 2012-2014: prospective, repeated cross-sectional study

OBJECTIVES

To investigate the prevalence and risk factors for asymptomatic toxigenic (TCD) and nontoxigenic Clostridium difficile (NTCD) colonization in a broad cross section of the general hospital population over a 3-year period.

METHODS

Patients without diarrhoea admitted to two Australian tertiary hospitals were randomly selected through six repeated cross-sectional surveys conducted between 2012 and 2014. Stool specimens were cultured under anaerobic conditions, and C. difficile isolates were tested for the presence of toxin genes and ribotyped. Patients were then grouped into noncolonized, TCD colonized or NTCD colonized for identifying risk factors using multinomial logistic regression models.

RESULTS

A total of 1380 asymptomatic patients were enrolled; 76 patients (5.5%) were TCD colonized and 28 (2.0%) were NTCD colonized. There was a decreasing annual trend in TCD colonization, and asymptomatic colonization was more prevalent during the summer than winter months. TCD colonization was associated with gastro-oesophageal reflux disease (relative risk ratio (RRR) = 2.20; 95% confidence interval (CI) 1.17-4.14), higher number of admissions in the previous year (RRR = 1.24; 95% CI 1.10-1.39) and antimicrobial exposure during the current admission (RRR = 2.78; 95% CI 1.23-6.28). NTCD colonization was associated with chronic obstructive pulmonary disease (RRR = 3.88; 95% CI 1.66-9.07) and chronic kidney failure (RRR = 5.78; 95% CI 2.29-14.59). Forty-eight different ribotypes were identified, with 014/020 (n = 23), 018 (n = 10) and 056 (n = 6) being the most commonly isolated.

CONCLUSIONS

Risk factors differ between patients with asymptomatic colonization by toxigenic and nontoxigenic strains. Given that morbidity is largely driven by toxigenic strains, this novel finding has important implications for disease control and prevention.

Optimizing the diagnostic testing of Clostridium difficile infection

INTRODUCTION

Clostridium difficile infection (CDI) is the leading cause of hospital-acquired diarrhea and is associated with a considerable health and cost burden. However, there is still not a clear consensus on the best laboratory diagnosis approach and a wide variation of testing methods and strategies can be encountered.

AREAS COVERED

We aim to review the most practical aspects of CDI diagnosis providing our own view on how to optimize CDI diagnosis. Expert commentary: Laboratory diagnosis in search of C. difficile toxins should be applied to all fecal diarrheic samples reaching the microbiology laboratory in patients > 2 years old, with or without classic risk factors for CDI. Detection of toxins either directly in the fecal sample or in the bacteria isolated in culture confirm CDI in the proper clinical setting. Nuclear Acid Assay techniques (NAAT) allow to speed up the process with epidemiological and therapeutic consequences.

Low frequency of asymptomatic carriage of toxigenic Clostridium difficile in an acute care geriatric hospital: prospective cohort study in Switzerland

Background

The role of asymptomatic carriers of toxigenic Clostridium difficile (TCD) in nosocomial cross-transmission remains debatable. Moreover, its relevance in the elderly has been sparsely studied.

Objectives

To assess asymptomatic TCD carriage in an acute care geriatric population.

Methods

We performed a prospective cohort study at the 296-bed geriatric hospital of the Geneva University Hospitals. We consecutively recruited all patients admitted to two 15-bed acute-care wards. Patients with C. difficile infection (CDI) or diarrhoea at admission were excluded. First bowel movement after admission and every two weeks thereafter were sampled. C. difficile toxin B gene was identified using real-time polymerase chain-reaction (BD MAX^TMCdiff). Asymptomatic TCD carriage was defined by the presence of the C. difficile toxin B gene without diarrhoea.

Results

A total of 102 patients were admitted between March and June 2015. Two patients were excluded. Among the 100 patients included in the study, 63 were hospitalized and 1 had CDI in the previous year, and 36 were exposed to systemic antibiotics within 90 days prior to admission. Overall, 199 stool samples were collected (median 2 per patient, IQR 1-3). Asymptomatic TCD carriage was identified in two patients (2 %).

Conclusions

We found a low prevalence of asymptomatic TCD carriage in a geriatric population frequently exposed to antibiotics and healthcare. Our findings suggest that asymptomatic TCD carriage might contribute only marginally to nosocomial TCD cross-transmission in our and similar healthcare settings.

Recurrent Clostridium difficile infection and the microbiome

The diverse and densely populated gastrointestinal microbiota is essential for the regulation of host physiology and immune function. As our knowledge of the composition and function of the intestinal microbiota continues to expand, there is new interest in using these developments to tailor fecal microbiota transplantation (FMT) and microbial ecosystem therapeutics (MET) for a variety of diseases. The potential role of FMT and MET in the treatment of Clostridium difficile infection (CDI)-currently the leading nosocomial gastrointestinal infection-has proven highly effective for recurrent CDI, and has emerged as a paradigm shift in the treatment of this disease. The current review will serve as a summary of the key aspects of CDI, and will introduce the essential framework and challenges of FMT, as is currently practiced. MET represents the progression of conventional bacteriotherapy that fundamentally capitalizes on the restorative properties of intestinal bacterial communities and may be viewed as the culmination of a rationally designed therapeutic modality. As our understanding of the composition and function of the intestinal microbiota evolves, it will likely drive next-generation microbiota therapies for a range of medical conditions, such as inflammatory bowel disease, obesity, and metabolic syndrome.

Asymptomatic Clostridium difficile colonization: epidemiology and clinical implications

BACKGROUND

The epidemiology of Clostridium difficile infection (CDI) has changed over the past decades with the emergence of highly virulent strains. The role of asymptomatic C. difficile colonization as part of the clinical spectrum of CDI is complex because many risk factors are common to both disease and asymptomatic states. In this article, we review the role of asymptomatic C. difficile colonization in the progression to symptomatic CDI, describe the epidemiology of asymptomatic C. difficile colonization, assess the effectiveness of screening and intensive infection control practices for patients at risk of asymptomatic C. difficile colonization, and discuss the implications for clinical practice.

METHODS

A narrative review was performed in PubMed for articles published from January 1980 to February 2015 using search terms 'Clostridium difficile' and 'colonization' or 'colonisation' or 'carriage'.

RESULTS

There is no clear definition for asymptomatic CDI and the terms carriage and colonization are often used interchangeably. The prevalence of asymptomatic C. difficile colonization varies depending on a number of host, pathogen, and environmental factors; current estimates of asymptomatic colonization may be underestimated as stool culture is not practical in a clinical setting.

CONCLUSIONS

Asymptomatic C. difficile colonization presents challenging concepts in the overall picture of this disease and its management. Individuals who are colonized by the organism may acquire protection from progression to disease, however they also have the potential to contribute to transmission in healthcare settings.

The Bug Stops Here: Innate Lymphoid Cells in Clostridium difficile Infection

The contribution of the innate immune response to the resolution of Clostridium difficile infection (CDI) remains incompletely defined. In this issue of Cell Host & Microbe, Abt et al. demonstrated that innate lymphoid cells and the effector cytokine IFN-γ are important for recovery from the acute phase of CDI.