Clostridium difficile-associated diarrhoea in hospitalised patients

Phase Variation of Flagella and Toxins in Clostridioides difficile is Mediated by Selective Rho-dependent Termination

Clostridioides difficile is an intestinal pathogen that exhibits phase variation of flagella and toxins through inversion of the flagellar (flg) switch controlling flagellar and toxin gene expression. The transcription termination factor Rho preferentially inhibits swimming motility of bacteria with the 'flg-OFF' switch sequence. How C. difficile Rho mediates this selectivity was unknown. C. difficile Rho contains an N-terminal insertion domain (NID) which is found in a subset of Rho orthologues and confers diverse functions. Here we determined how Rho distinguishes between flg-ON and -OFF mRNAs and the roles of the NID and other domains of C. difficile Rho. Using in vitro ATPase assays, we determined that Rho specifically binds a region containing the left inverted repeat of the flg switch, but only of flg-OFF mRNA, indicating that differential termination is mediated by selective Rho binding. Using a suite of in vivo and in vitro assays in C. difficile, we determined that the NID is essential for Rho termination of flg-OFF mRNA, likely by influencing the ability to form stable hexamers, and the RNA binding domain is critical for flg-OFF specific termination. This work gives insight into the novel mechanism by which Rho interacts with flg mRNA to mediate phase variation of flagella and toxins in C. difficile and broadens our understanding of Rho-mediated termination in an organism with an AT-rich genome.

Economic Burden of Clostridioides difficile Infection in European Countries

Clostridioides difficile infection (CDI) remains a considerable challenge to healthcare systems worldwide. Although CDI represents a significant burden on healthcare systems in Europe, few studies have attempted to estimate the consumption of resources associated with CDI in Europe. The reported extra costs attributable to CDI vary widely according to the definitions, design, and methodologies used, making comparisons difficult to perform. In this chapter, the economic burden of healthcare facility-associated CDI in Europe will be assessed, as will other less explored areas such as the economic burden of recurrent CDI, community-acquired CDI, pediatric CDI, and CDI in outbreaks.

Clostridium Difficile Infection - Analysis of Risk Factors in Constanta

It has been estimated that the human gut contains about 1,000 species of bacteria and 100 times more genes than are found in the human genome. Over 2 Kg - as weight. It is the human microbiom that form a true “forgotten organ” of our body.

Due to the abuse of antibiotics, the Clostridium difficile infection became one of the top nosocomial infections due to complications and financial pressure on the medical system.

We conducted a prospective study of the characteristics of risk factors and epidemiological aspects in patients with Clostridium difficile infection admitted to the Clinical Hospital for Infectious Diseases from Constanta for a period of 3 years. Demographics (age), risk factors (surgery, history of antibiotics or proton pump inhibitors, comorbidities) were noted. The classes of antibiotics used, other than the basic treatment of the condition were analyzed. Also the source of the infection including the ward were the patient was previously hospitalized.

47% (104) of the patients were in the 60-80 interval of age. Nearly half of the patients had a history of surgery. Only 52 patients out of a total of 221 had no history of antibiotic therapy. More than half had PPI therapy prior to the onset of CD infection. In terms of comorbidities, they are multiple, at different systems, the most common being cardiovascular, nutritional and renal diseases. The source of infection was found as nosocomial in 65% of patients. Regarding the origin of the hospital wards, the surgical departments were the main ones in which CD infections appeared: General Surgery (46), Orthopedics (33) and Urology (13).

Our study results confirm that reported risk factors are advanced age, antibiotics use, proton pump inhibitors administration, comorbidities and exposure to health care sistem.

Economic burden and cost-effectiveness of therapies for Clostridiodes difficile infection: a narrative review

Clostridioides difficile is the most common cause of healthcare-associated diarrhea. Disease complications as well as recurrent infections contribute significantly to morbidity and mortality. Over the past decades, there has been a rapid increase in the incidence of C. difficile infection (CDI), with a rise in the number of community-acquired cases. CDI has a profound economic impact on both the healthcare system and patients, secondary to recurrences, hospitalization, prolonged length of stay, cost of treatment, and indirect societal costs. With emergence of newer treatment options, the standard of care is shifting from metronidazole and vancomycin towards fidaxomicin and fecal microbiota transplantation (FMT), which despite being more expensive, are more efficacious in preventing recurrences and hence overall are more beneficial forms of therapy per cost-effectiveness analyses. Data regarding preferred route of FMT, timing of FMT, and non-conventional therapies such as bezlotoxumab is scant. There is a need for further studies to elucidate the true attributable costs of CDI as well as continued cost-effectiveness research to reduce the economic burden associated with the disease and improve clinical practice.

Economic Burden of Clostridium difficile Infection in European Countries

Clostridium difficile infection (CDI) remains a considerable challenge to health care systems worldwide. Although CDI represents a significant burden on healthcare systems in Europe, few studies have attempted to estimate the consumption of resources associated with CDI in Europe. The reported extra costs attributable to CDI vary widely according to the definitions, design, and methodologies used, making comparisons difficult to perform. In this chapter, the economic burden of healthcare facility-associated CDI in Europe will be assessed, as will other less explored areas such as the economic burden of recurrent CDI, community-acquired CDI, pediatric CDI, and CDI in outbreaks.

Multiplex tests to identify gastrointestinal bacteria, viruses and parasites in people with suspected infectious gastroenteritis: a systematic review and economic analysis

BACKGROUND

Gastroenteritis is a common, transient disorder usually caused by infection and characterised by the acute onset of diarrhoea. Multiplex gastrointestinal pathogen panel (GPP) tests simultaneously identify common bacterial, viral and parasitic pathogens using molecular testing. By providing test results more rapidly than conventional testing methods, GPP tests might positively influence the treatment and management of patients presenting in hospital or in the community.

OBJECTIVE

To systematically review the evidence for GPP tests [xTAG^® (Luminex, Toronto, ON, Canada), FilmArray (BioFire Diagnostics, Salt Lake City, UT, USA) and Faecal Pathogens B (AusDiagnostics, Beaconsfield, NSW, Australia)] and to develop a de novo economic model to compare the cost-effectiveness of GPP tests with conventional testing in England and Wales.

DATA SOURCES

Multiple electronic databases including MEDLINE, EMBASE, Web of Science and the Cochrane Database were searched from inception to January 2016 (with supplementary searches of other online resources).

REVIEW METHODS

Eligible studies included patients with acute diarrhoea; comparing GPP tests with standard microbiology techniques; and patient, management, test accuracy or cost-effectiveness outcomes. Quality assessment of eligible studies used tailored Quality Assessment of Diagnostic Accuracy Studies-2, Consolidated Health Economic Evaluation Reporting Standards and Philips checklists. The meta-analysis included positive and negative agreement estimated for each pathogen. A de novo decision tree model compared patients managed with GPP testing or comparable coverage with patients managed using conventional tests, within the Public Health England pathway. Economic models included hospital and community management of patients with suspected gastroenteritis. The model estimated costs (in 2014/15 prices) and quality-adjusted life-year losses from a NHS and Personal Social Services perspective.

RESULTS

Twenty-three studies informed the review of clinical evidence (17 xTAG, four FilmArray, two xTAG and FilmArray, 0 Faecal Pathogens B). No study provided an adequate reference standard with which to compare the test accuracy of GPP with conventional tests. A meta-analysis (of 10 studies) found considerable heterogeneity; however, GPP testing produces a greater number of pathogen-positive findings than conventional testing. It is unclear whether or not these additional 'positives' are clinically important. The review identified no robust evidence to inform consequent clinical management of patients. There is considerable uncertainty about the cost-effectiveness of GPP panels used to test for suspected infectious gastroenteritis in hospital and community settings. Uncertainties in the model include length of stay, assumptions about false-positive findings and the costs of tests. Although there is potential for cost-effectiveness in both settings, key modelling assumptions need to be verified and model findings remain tentative.

LIMITATIONS

No test-treat trials were retrieved. The economic model reflects one pattern of care, which will vary across the NHS.

CONCLUSIONS

The systematic review and cost-effectiveness model identify uncertainties about the adoption of GPP tests within the NHS. GPP testing will generally correctly identify pathogens identified by conventional testing; however, these tests also generate considerable additional positive results of uncertain clinical importance.

FUTURE WORK

An independent reference standard may not exist to evaluate alternative approaches to testing. A test-treat trial might ascertain whether or not additional GPP 'positives' are clinically important or result in overdiagnoses, whether or not earlier diagnosis leads to earlier discharge in patients and what the health consequences of earlier intervention are. Future work might also consider the public health impact of different testing treatments, as test results form the basis for public health surveillance.

STUDY REGISTRATION

This study is registered as PROSPERO CRD2016033320.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

A Systematic Literature Review of Economic Evaluations of Antibiotic Treatments for Clostridium difficile Infection

BACKGROUND AND OBJECTIVE

Clostridium difficile infection (CDI) is associated with high management costs, particularly in recurrent cases. Fidaxomicin treatment results in lower recurrence rates than vancomycin and metronidazole, but has higher acquisition costs in Europe and the USA. This systematic literature review summarises economic evaluations (EEs) of fidaxomicin, vancomycin and metronidazole for treatment of CDI.

METHODS

Electronic databases (MEDLINE®, Embase, Cochrane Library) and conference proceedings (ISPOR, ECCMID, ICAAC and IDWeek) were searched for publications reporting EEs of fidaxomicin, vancomycin and/or metronidazole in the treatment of CDI. Reference bibliographies of identified manuscripts were also reviewed. Cost-effectiveness was evaluated according to the overall population of patients with CDI, as well as in subgroups with severe CDI or recurrent CDI, or those at higher risk of recurrence or mortality.

RESULTS

Overall, 27 relevant EEs, conducted from the perspective of 12 different countries, were identified. Fidaxomicin was cost-effective versus vancomycin and/or metronidazole in 14 of 24 EEs (58.3%), vancomycin was cost-effective versus fidaxomicin and/or metronidazole in five of 27 EEs (18.5%) and metronidazole was cost-effective versus fidaxomicin and/or vancomycin in two of 13 EEs (15.4%). Fidaxomicin was cost-effective versus vancomycin in most of the EEs evaluating specific patient subgroups. Key cost-effectiveness drivers were cure rate, recurrence rate, time horizon, drug costs and length and cost of hospitalisation.

CONCLUSIONS

In most EEs, fidaxomicin was demonstrated to be cost-effective versus metronidazole and vancomycin in patients with CDI. These results have relevance to clinical practice, given the high budgetary impact of managing CDI and increasing restrictions on healthcare budgets.

OTHER

This analysis was initiated and funded by Astellas Pharma Inc.

A DNA vaccine targeting TcdA and TcdB induces protective immunity against Clostridium difficile

Background

Clostridium difficile-associated disease (CDAD) constitutes a great majority of hospital diarrhea cases in industrialized countries and is induced by two types of large toxin molecules: toxin A (TcdA) and toxin B (TcdB). Development of immunotherapeutic approaches, either active or passive, has seen a resurgence in recent years. Studies have described vaccine plasmids that express either TcdA and/or TcdB receptor binding domain (RBD). However, the effectiveness of one vector encoding both toxin RBDs against CDAD has not been evaluated.

Methods

In the study, we constructed highly optimized plasmids to express the receptor binding domains of both TcdA and TcdB from a single vector. The DNA vaccine was evaluated in two animal models for its immunogenicity and protective effects.

Results

The DNA vaccine induced high levels of serum antibodies to toxin A and/or B and demonstrated neutralizing activity in both in vitro and in vivo systems. In a C. difficile hamster infection model, immunization with the DNA vaccine reduced infection severity and conferred significant protection against a lethal C. difficile strain.

Conclusions

This study has demonstrated a single plasmid encoding the RBD domains of C. difficile TcdA and TcdB as a DNA vaccine that could provide protection from C. difficile disease.

Analysis of risk factors and clinical manifestations associated with Clostridium difficile disease in Serbian hospitalized patients

Clostridium difficile is the leading cause of infectious diarrhoea in hospitalized patients. The aim of this study was to determine the risk factors important for the development of hospital-acquired Clostridium difficile-associated disease and clinical manifestations of Clostridium difficile-associated disease. The clinical trial group included 37 hospitalized patients who were selected according to the inclusion criteria. A control group of 74 hospitalized patients was individually matched with cases based on hospital, age (within 4 years), sex and month of admission. Clostridium difficile-associated disease most commonly manifested as diarrhoea (56.76%) and colitis (32%), while in 8.11% of patients, it was diagnosed as pseudomembranous colitis, and in one patient, it was diagnosed as fulminant colitis. Statistically significant associations (p<0.05) were found with the presence of chronic renal failure, chronic obstructive pulmonary disease, cerebrovascular accident (stroke) and haemodialysis. In this study, it was confirmed that all the groups of antibiotics, except for tetracycline and trimethoprim-sulfamethoxazole, were statistically significant risk factors for Clostridium difficile-associated disease (p<0.05). However, it was difficult to determine the individual role of antibiotics in the development of Clostridium difficile-associated disease. Univariate logistic regression also found that applying antibiotic therapy, the duration of antibiotic therapy, administration of two or more antibiotics to treat infections, administering laxatives and the total number of days spent in the hospital significantly affected the onset of Clostridium difficile-associated disease (p<0.05), and associations were confirmed using the multivariate model for the application of antibiotic therapy (p=0.001), duration of antibiotic treatment (p=0.01), use of laxatives (p=0.01) and total number of days spent in the hospital (p=0.001). In this study of patients with hospital-acquired diarrhoea, several risk factors for the development of Clostridium difficile-associated disease were identified.

A cost-effectiveness and budget impact analysis of first-line fidaxomicin for patients with Clostridium difficile infection (CDI) in Germany

PURPOSE

Clostridium difficile infection (CDI) represents a significant economic healthcare burden, especially the cost of recurrent disease. Fidaxomicin produced significantly lower recurrence rates and higher sustained cure rates in clinical trials. We evaluated the cost-effectiveness and budget impact of fidaxomicin compared with vancomycin in Germany in the first-line treatment of patient subgroups with CDI at increased risk of recurrence.

METHODS

A semi-Markov model was used to compare the cost-effectiveness and budget impact of fidaxomicin vs. vancomycin from a payer perspective in Germany. The model cycle length was 10 days. The time horizon was 1 year. Model inputs were probability of clinical cure, 30-day probability of recurrence, and 30-day attributable mortality based on evidence from two randomized controlled trials comparing fidaxomicin and vancomycin in patients with CDI. Cost-effectiveness outcomes were cost per quality-adjusted life year gained, cost per bed-day saved, and cost per recurrence avoided.

RESULTS

Despite higher drug acquisition costs, fidaxomicin was dominant in the cancer subgroup (less costly and more effective) and cost-effective in the other subgroups, with incremental cost-effectiveness ratios vs. vancomycin ranging from €26,900 to €44,500. Hospitalization costs of the first-line treatment of CDI with fidaxomicin vs. vancomycin were lower in every patient subgroup, resulting in budget impacts ranging from -€1325 (in patients ≥65 years) to -€2438 (in cancer patients). Reductions in the cost of treating recurrence with fidaxomicin ranged from -€574.32 per patient in those receiving concomitant antibiotics to -€1500.68 per patient in renally impaired patients.

CONCLUSIONS

In patient subgroups with CDI at increased recurrence risk, fidaxomicin was cost-effective vs. vancomycin, and less costly and more effective in patients with cancer.

Cost analysis of hospitalized Clostridium difficile-associated diarrhea (CDAD)

Aim:Clostridium difficile-associated diarrhea (CDAD) causes heavy financial burden on healthcare systems worldwide. As with all hospital-acquired infections, prolonged hospital stays are the main cost driver. Previous cost studies only include hospital billing data and compare the length of stay in contrast to non-infected patients. To date, a survey of actual cost has not yet been conducted.

Method: A retrospective analysis of data for patients with nosocomial CDAD was carried out over a 1-year period at the University Hospital of Greifswald. Based on identification of CDAD related treatment processes, cost of hygienic measures, antibiotics and laboratory as well as revenue losses due to bed blockage and increased length of stay were calculated.

Results: 19 patients were included in the analysis. On average, a CDAD patient causes additional costs of € 5,262.96. Revenue losses due to extended length of stay take the highest proportion with € 2,555.59 per case, followed by loss in revenue due to bed blockage during isolation with € 2,413.08 per case. Overall, these opportunity costs accounted for 94.41% of total costs. In contrast, costs for hygienic measures (€ 253.98), pharmaceuticals (€ 22.88) and laboratory (€ 17.44) are quite low.

Conclusion: CDAD results in significant additional costs for the hospital. This survey of actual costs confirms previous study results.

Economic Evaluation of Fidaxomicin for the Treatment of Clostridium Difficile Infection (C. difficile-associated diarrhoea) in Ireland

Background: Clostridium difficile is associated with 20-30% of cases of antibiotic-associated diarrhoea. The incidence of C. difficile infection (CDI) is higher in Ireland than in other countries in Europe, and it is associated with considerable morbidity. Previously recommended standard therapeutic options were vancomycin and metronidazole, but the macrocyclic antibiotic fidaxomicin has recently been recommended for use in adults with CDI in Ireland. Objectives: To perform a cost-utility analysis of fidaxomicin compared to oral metronidazole (used to treat initial non-severe disease and first non-severe recurrence) and oral vancomycin (used to treat severe disease and any non-severe recurrence beyond the first) for the treatment of CDI. Methods: A Markov model was used to determine the cost-utility of fidaxomicin in the treatment of all adult CDI patients (base case), patients with severe CDI and patients with initial CDI recurrences, respectively. Patients enter the model in the CDI health state and are treated either with fidaxomicin or current standard of care (oral metronidazole for non-severe CDI; vancomycin for severe CDI) for 10 days. The time horizon was 1 year. Deterministic and probabilistic sensitivity analyses were performed. Health state utilities were derived from the literature. The perspective was that of the Irish Health Service Executive (HSE). Results: In the base case, fidaxomicin was dominant to current standard-of-care therapy, with cost savings of €2,904 and incremental quality-adjusted life year (QALY) gain of 0.031. The main drivers of costeffectiveness were recurrence rates and cost of hospitalization. Fidaxomicin was also dominant for all patient subgroups. The probability of fidaxomicin being cost-effective in all patients with CDI at a willingness to pay threshold of €45,000 per QALY gained was 82%. Conclusion: Fidaxomicin was dominant to the current standard-of-care therapy for CDI. Based on this analysis, fidaxomicin has received reimbursement for CDI treatment under the High Tech Drug Scheme in Ireland.

The economic impact of Clostridium difficile infection: a systematic review

OBJECTIVES

With Clostridium difficile infection (CDI) on the rise, knowledge of the current economic burden of CDI can inform decisions on interventions related to CDI. We systematically reviewed CDI cost-of-illness (COI) studies.

METHODS

We performed literature searches in six databases: MEDLINE, Embase, the Health Technology Assessment Database, the National Health Service Economic Evaluation Database, the Cost-Effectiveness Analysis Registry, and EconLit. We also searched gray literature and conducted reference list searches. Two reviewers screened articles independently. One reviewer abstracted data and assessed quality using a modified guideline for economic evaluations. The second reviewer validated the abstraction and assessment.

RESULTS

We identified 45 COI studies between 1988 and June 2014. Most (84%) of the studies were from the United States, calculating costs of hospital stays (87%), and focusing on direct costs (100%). Attributable mean CDI costs ranged from $8,911 to $30,049 for hospitalized patients. Few studies stated resource quantification methods (0%), an epidemiological approach (0%), or a justified study perspective (16%) in their cost analyses. In addition, few studies conducted sensitivity analyses (7%).

CONCLUSIONS

Forty-five COI studies quantified and confirmed the economic impact of CDI. Costing methods across studies were heterogeneous. Future studies should follow standard COI methodology, expand study perspectives (e.g., patient), and explore populations least studied (e.g., community-acquired CDI).

Cost and Impact on Patient Length of Stay of Rapid Molecular Testing for Clostridium difficile

Introduction

A study was performed to assess the cost of a rapid molecular assay (PCR) for diagnosis of Clostridium difficile infection (CDI) and the impact of its routine use on patient length of stay (LOS) in comparison with cell culture cytotoxin neutralization assay (CCNA).

Methods

From March 2011 to September 2011, Xpert^®C. difficile (Cepheid, Sunnyvale, CA, USA) PCR was used on patients with suspicion of CDI in two acute care hospitals in Abertawe Bro Morgannwg University Health Board, Swansea, Wales, UK. Test results were used for patient management. LOS and time to reportable result were compared for negative and positive prospective patients tested by PCR and historic control patients tested by CCNA during March 2010 to September 2010. Tests were priced using micro-costing and a cost comparison analysis was undertaken.

Results

In total, 506 patients were included. Time to reportable result for PCR samples was 1.53 h compared to 46.54 h for CCNA negatives and 22.45 h for CCNA positives. Patients tested by CCNA stayed 4.88 days longer in hospital compared to PCR patients if they tested positive and 7.03 days if tests were negative. The mean reduction in LOS observed in our study has the potential to generate cost savings of up to £2,292.62 for every patient with suspected CDI, if samples were to be tested routinely with PCR instead of CCNA.

Conclusion

A rapid molecular test for C. difficile in an acute hospital setting produced quick results that led to a decrease in LOS compared to historic CCNA control patients. This could result in considerable savings through reduced excess inpatient days.

Electronic supplementary material

The online version of this article (doi:10.1007/s40121-014-0034-x) contains supplementary material, which is available to authorized users.

Cost-effectiveness analysis of fidaxomicin versus vancomycin in Clostridium difficile infection

Objectives

Fidaxomicin was non-inferior to vancomycin with respect to clinical cure rates in the treatment of Clostridium difficile infections (CDIs) in two Phase III trials, but was associated with significantly fewer recurrences than vancomycin. This economic analysis investigated the cost-effectiveness of fidaxomicin compared with vancomycin in patients with severe CDI and in patients with their first CDI recurrence.

Methods

A 1 year time horizon Markov model with seven health states was developed from the perspective of Scottish public healthcare providers. Model inputs for effectiveness, resource use, direct costs and utilities were obtained from published sources and a Scottish expert panel. The main model outcome was the incremental cost-effectiveness ratio (ICER), expressed as cost per quality-adjusted life year (QALY), for fidaxomicin versus vancomycin; ICERs were interpreted using willingness-to-pay thresholds of £20 000/QALY and £30 000/QALY. One-way and probabilistic sensitivity analyses were performed.

Results

Total costs were similar with fidaxomicin and vancomycin in patients with severe CDI (£14 515 and £14 344, respectively) and in patients with a first recurrence (£16 535 and £16 926, respectively). Improvements in clinical outcomes with fidaxomicin resulted in small QALY gains versus vancomycin (severe CDI, +0.010; patients with first recurrence, +0.019). Fidaxomicin was cost-effective in severe CDI (ICER £16 529/QALY) and dominant (i.e. more effective and less costly) in patients with a first recurrence. The probability that fidaxomicin was cost-effective at a willingness-to-pay threshold of £30 000/QALY was 60% for severe CDI and 68% in a first recurrence.

Conclusions

Fidaxomicin is cost-effective in patients with severe CDI and in patients with a first CDI recurrence versus vancomycin.

Clinical efficacy of fidaxomicin compared with vancomycin and metronidazole in Clostridium difficile infections: a meta-analysis and indirect treatment comparison

OBJECTIVES

To evaluate the efficacy of fidaxomicin treatment, which has a limited effect on the normal gut flora, compared with vancomycin and metronidazole treatment in Clostridium difficile infections (CDIs).

METHODS

A systematic literature review was conducted in July to August 2011 and updated in July 2013. For fidaxomicin versus vancomycin, efficacy was evaluated using meta-analysis of data from two Phase III direct comparative studies (n = 1164). As there were no studies comparing fidaxomicin and metronidazole, an indirect comparison was made using data from three vancomycin versus metronidazole studies (n = 345), using the methodology of Bucher et al. (J Clin Epidemiol 1997; 50: 683-91). This provides an OR for the indirect comparison of fidaxomicin versus metronidazole when direct evidence of fidaxomicin versus vancomycin and vancomycin versus metronidazole is available.

RESULTS

Clinical cure rates were similar for fidaxomicin and vancomycin; the OR (95% CI) was 1.17 (0.82, 1.66). Recurrence [0.47 (0.34, 0.65)] was significantly lower and sustained cure rates [1.75 (1.35, 2.27)] significantly higher for fidaxomicin than vancomycin. Similar results were obtained in patient subgroups with severe CDI and with non-severe CDI. From the indirect comparison, the likelihood of recurrence [0.42 (0.18, 0.96)] and sustained cure [2.55 (1.44, 4.51)] were significantly improved for fidaxomicin versus metronidazole. Again, similar results were obtained in those with severe and non-severe CDI.

CONCLUSIONS

Fidaxomicin provides improved sustained cure rates in patients with CDI compared with vancomycin. An indirect comparison indicates that the same is also true for fidaxomicin versus metronidazole. In view of these data, fidaxomicin may be considered as first-line therapy for CDI.

A review of the economics of treating Clostridium difficile infection

Clostridium difficile infection (CDI) is a costly result of antibiotic use, responsible for an estimated 14,000 deaths annually in the USA according to the Centers for Disease Control and Prevention. Annual costs attributable to CDI are in excess of $US 1 billion. This review summarizes appropriate utilization of prevention and treatment methods for CDI that have the potential to reduce the economic and humanistic costs of the disease. Some cost-effective strategies to prevent CDI include screening and isolation of hospital admissions based on C. difficile carriage to reduce transmission in the inpatient setting, and probiotics, which are potentially efficacious in preventing CDI in the appropriate patient population. The most extensively studied agents for treatment of CDI are metronidazole, vancomycin, and fidaxomicin. Most economic comparisons between metronidazole and vancomycin favor vancomycin, especially with the emergence of metronidazole-resistant C. difficile strains. Metronidazole can only be recommended for mild disease. Moderate to severe CDI should be treated with vancomycin, preferably the compounded oral solution, which provides the most cost-effective therapeutic option. Fidaxomicin offers a clinically effective and potentially cost-effective alternative for treating moderate CDI in patients who do not have the NAP1/BI/027 strain of C. difficile. Probiotics and fecal microbiota transplant have variable efficacy and the US FDA does not currently regulate the content; the potential economic advantages of these treatment modalities are currently unknown.

Antimicrobial susceptibility of Enterococcus strains used in clinical practice as probiotics

The aim of this study was to evaluate the antimicrobial susceptibilities of probiotic strains that are suggested to be effective for preventing antibiotics-associated diarrhea (AAD). The minimum inhibitory concentrations (MICs) of 17 antibiotics against probiotic strains were tested by the agar plate dilution method or broth microdilution method. In all, eight probiotic strains containing Enterococcus faecalis, Bifidobacterium spp., Clostridium butyricum, and Lactobacillus acidophilus were tested. Although the MIC range was wide, from less than 0.0625 to more than 1,024 μg/ml, the MICs of 11 beta-lactams were high for three of four enterococci, with a range of 32 to more than 1,024 μg/ml. In contrast, fluoroquinolones and vancomycin showed potent activities against all enterococci, of which MICs were 0.25-8 μg/ml. Two Bifidobacterium strains and one Lactobacillus strain showed low MICs against many of the beta-lactams, fluoroquinolones, macrolides, and vancomycin, with MICs of 8 μg/ml or less. Fosfomycin showed generally mild activity against enterococci (MIC, 8-32 μg/ml) and anaerobic strains (MIC, 32 to >1,024 μg/ml), respectively. The probiotics strains with high MIC values may survive in the intestinal tract, even if the patient was concomitantly using the antibiotics in clinical practice. Therefore, our results suggest that adequate combinations of probiotics strains and antibiotics should be important for preventing AAD. Further study is needed to determine the efficacy of probiotics in clinical practice.

Acute osteomyelitis of the humerus mimicking malignancy: Streptococcus pneumoniae as exceptional pathogen in an immunocompetent adult

Background

Chronic osteomyelitis due to direct bone trauma or vascular insufficiency is a frequent problem in orthopaedic surgery. In contrast, acute haematogenous osteomyelitis represents a rare entity that almost exclusively affects prepubescent children or immunodeficient adults.

Case Presentation

In this article, we report the case of acute pneumococcal osteomyelitis of the humerus in an immunocompetent and otherwise healthy 44-year-old male patient presenting with minor inflammation signs and misleading clinical features.

Conclusions

The diagnosis had to be confirmed by open biopsy which allowed the initiation of a targeted therapy. A case of pneumococcal osteomyelitis of a long bone, lacking predisposing factors or trauma, is unique in adults and has not been reported previously.

Do statins protect against the development of Clostridium difficile-associated diarrhoea?

OBJECTIVES

To assess whether prior statin use protects against the development of Clostridium difficile-associated diarrhoea (CDAD) in hospitalized patients.

PATIENTS AND METHODS

A retrospective case-control study conducted in three hospitals included all hospitalized patients diagnosed with CDAD in the Internal Medicine Departments (IMDs) during a 1 year period. Subjects were determined to have CDAD if their stool sample was positive for C. difficile toxin in the context of diarrhoea at the time of diagnosis. Patients with CDAD were compared with patients without CDAD, hospitalized during the same period and in the same departments, matched for age, gender, comorbidities (Charlson score), length of hospitalization and antibiotic use during the last 3 months.

RESULTS

Prevalence of CDAD was 2.87% (197/6850 patients hospitalized in the IMDs). The 197 cases with CDAD were compared with 169 hospitalized patient controls. Sixty-four out of 197 (32.5%) patients in the CDAD group were statin users versus 87/169 (51.5%) of the controls (P = 0.02). Multivariate analysis showed that a Charlson score >3 [OR = 2.2 (95% CI 1.8-2.8), P = 0.024], chemotherapy during the last 6 months [OR = 3.09 (95% CI 1.95-3.91), P = 0.002], a history of intra-abdominal surgery [OR = 2.99 (95% CI 2.58-3.24), P = 0.003] and no statin use [OR = 2.2 (95% CI 1.82-2.73), P = 0.034] were associated with CDAD.

CONCLUSIONS

Prior statin use may provide protection against CDAD. Further studies are warranted to evaluate this association.

Guidelines for diagnosis, treatment, and prevention of Clostridium difficile infections

Clostridium difficile infection (CDI) is a leading cause of hospital-associated gastrointestinal illness and places a high burden on our health-care system. Patients with CDI typically have extended lengths-of-stay in hospitals, and CDI is a frequent cause of large hospital outbreaks of disease. This guideline provides recommendations for the diagnosis and management of patients with CDI as well as for the prevention and control of outbreaks while supplementing previously published guidelines. New molecular diagnostic stool tests will likely replace current enzyme immunoassay tests. We suggest treatment of patients be stratified depending on whether they have mild-to-moderate, severe, or complicated disease. Therapy with metronidazole remains the choice for mild-to-moderate disease but may not be adequate for patients with severe or complicated disease. We propose a classification of disease severity to guide therapy that is useful for clinicians. We review current treatment options for patients with recurrent CDI and recommendations for the control and prevention of outbreaks of CDI.

Clostridium difficile 027-associated pseudomembranous colitis after short-term treatment with cefuroxime and cephalexin in an elderly orthopedic patient: a case report

BACKGROUND

Clostridium difficile ribotype 027 has become increasingly prevalent in European countries. The clinical picture varies from self-limiting diarrhea to pseudomembranous colitis with toxic megacolon and ultimately death. Use of antibiotics is the principal risk factor; others include comorbidity, advanced age and hospitalization. However even with extensive knowledge of risk factors, it remains difficult to define "minimum risk," as illustrated by the following case.

CASE PRESENTATION

An 80-year-old Danish man in good health was hospitalized for a penetrating knee injury. He received 5 days of intravenous cefuroxime after surgical revision and was discharged with oral cephalexin. Post-discharge he suffered from abdominal discomfort and was readmitted with ileus 4 days after discharge, i.e. 10 days after initiation of antibiotic treatment. His condition deteriorated, and pseudomembranous colitis was diagnosed. Due to lack of response to vancomycin and metronidazole, a total colectomy was performed. Stool cultures were positive for CD 027.

CONCLUSION

Short-term use of cephalosporins may have induced CD 027 infection, and the patient's age was the only identifiable risk factor for the fulminant course. Thus, even short-term prophylactic treatment with cephalosporins cannot be considered entirely safe.

Clinical and economic burden of Clostridium difficile infection in Europe: a systematic review of healthcare-facility-acquired infection

PubMed, EMBASE and conference abstracts were reviewed systematically to determine the clinical and economic burden associated with Clostridium difficile infection (CDI) acquired and treated in European healthcare facilities. Inclusion criteria were: published in the English language between 2000 and 2010, and study population of at least 20 patients with documented CDI acquired/treated in European healthcare facilities. Data collection was completed by three unblinded reviewers using the Cochrane Handbook and PRISMA statement. The primary outcomes were mortality, recurrence, length of hospital stay (LOS) and cost related to CDI. In total, 1138 primary articles and conference abstracts were identified, and this was narrowed to 39 and 30 studies, respectively. Data were available from 14 countries, with 47% of studies from UK institutions. CDI mortality at 30 days ranged from 2% (France) to 42% (UK). Mortality rates more than doubled from 1999 to 2004, and continued to rise until 2007 when reductions were noted in the UK. Recurrent CDI varied from 1% (France) to 36% (Ireland); however, recurrence definitions varied between studies. Median LOS ranged from eight days (Belgium) to 27 days (UK). The incremental cost of CDI was £4577 in Ireland and £8843 in Germany, after standardization to 2010 prices. Country-specific estimates, weighted by sample size, ranged from 2.8% to 29.8% for 30-day mortality and from 16 to 37 days for LOS. CDI burden in Europe was most commonly described using 30-day mortality, recurrence, LOS and cost data. The continued spread of CDI and resultant healthcare burden underscores the need for judicious use of antibiotics.

The Experimental Use of Syrian Hamsters

The Syrian hamster (Mesocricetus auratus) is a widely used experimental animal model. This chapter focuses primarily on the most current research uses of the hamster. More classical uses are covered only as they pertain to these current uses. Hamsters possess unique anatomical and physiological features, which make them desirable research models. Unlike other commonly used laboratory rodents, hamsters possess a cheek pouch, which can be easily everted and examined at both the gross and microscopic level. The hamster's relative size also allows for better visualization of certain biological systems including the respiratory and reproductive systems when compared to the mouse. Further, laboratory hamsters develop a variety of inherited diseases, which display similarities to human conditions. Hamsters possessing some of these inherited traits are commercially available. They are susceptible to a variety of carcinogens and develop tumors that other research animals less commonly develop. Also they are susceptible to the induction of a variety of metabolic disorders through the use of dietary manipulations. The antagonistic nature of hamsters is used to study the effect of treatment on male aggressive and defensive behaviors. Syrian hamsters display several unique characteristics that make them desired models for carcinogenesis studies.

The effect of hospital-acquired infection with Clostridium difficile on length of stay in hospital

BACKGROUND

The effect of hospital-acquired infection with Clostridium difficile on length of stay in hospital is not yet fully understood. We determined the independent impact of hospital-acquired infection with C. difficile on length of stay in hospital.

METHODS

We conducted a retrospective observational cohort study of admissions to hospital between July 1, 2002, and Mar. 31, 2009, at a single academic hospital. We measured the association between infection with hospital-acquired C. difficile and time to discharge from hospital using Kaplan-Meier methods and a Cox multivariable proportional hazards regression model. We controlled for baseline risk of death and accounted for C. difficile as a time-varying effect.

RESULTS

Hospital-acquired infection with C. difficile was identified in 1393 of 136,877 admissions to hospital (overall risk 1.02%, 95% confidence interval [CI] 0.97%-1.06%). The crude median length of stay in hospital was greater for patients with hospital-acquired C. difficile (34 d) than for those without C. difficile (8 d). Survival analysis showed that hospital-acquired infection with C. difficile increased the median length of stay in hospital by six days. In adjusted analyses, hospital-acquired C. difficile was significantly associated with time to discharge, modified by baseline risk of death and time to acquisition of C. difficile. The hazard ratio for discharge by day 7 among patients with hospital-acquired C. difficile was 0.55 (95% CI 0.39-0.70) for patients in the lowest decile of baseline risk of death and 0.45 (95% CI 0.32-0.58) for those in the highest decile; for discharge by day 28, the corresponding hazard ratios were 0.74 (95% CI 0.60-0.87) and 0.61 (95% CI 0.53-0.68).

INTERPRETATION

Hospital-acquired infection with C. difficile significantly prolonged length of stay in hospital independent of baseline risk of death.

Multihospital outbreak of Clostridium difficile ribotype 027 infection: epidemiology and analysis of control measures

OBJECTIVE

To report a large outbreak of Clostridium difficile infection (CDI; ribotype 027) between June 2007 and August 2008, describe infection control measures, and evaluate the impact of restricting the use of fluoroquinolones in controlling the outbreak.

DESIGN

Outbreak investigation in 3 acute care hospitals of the Northern Health and Social Care Trust in Northern Ireland.

INTERVENTIONS

Implementation of a series of CDI control measures that targeted high-risk antibiotic agents (ie, restriction of fluoroquinolones), infection control practices, and environmental hygiene.

RESULTS

A total of 318 cases of CDI were identified during the outbreak, which was the result of the interaction between C. difficile ribotype 027 being introduced into the affected hospitals for the first time and other predisposing risk factors (ranging from host factors to suboptimal compliance with antibiotic guidelines and infection control policies). The 30-day all-cause mortality rate was 24.5%; however, CDI was the attributable cause of death for only 2.5% of the infected patients. Time series analysis showed that restricting the use of fluoroquinolones was associated with a significant reduction in the incidence of CDI (coefficient, -0.054; lag time, 4 months; P = .003).

CONCLUSION

These findings provide additional evidence to support the value of antimicrobial stewardship as an essential element of multifaceted interventions to control CDI outbreaks. The present CDI outbreak was ended following the implementation of an action plan improving communication, antibiotic stewardship, infection control practices, environmental hygiene, and surveillance.

High Horn's index score predicts poor outcomes in patients with Clostridium difficile infection

Several variables have been proposed to predict the prognosis of patients with Clostridium difficile infection (CDI), but a clinically useful tool to stratify resource utilization has not been determined. Horn's index, a severity score based on underlying clinical illness, reliably predicts patients at high risk of CDI. The purpose of this study was to assess the use of Horn's index to stratify patients with CDI at high risk of poor clinical and economic outcomes. Hospitalized patients diagnosed with CDI were followed prospectively for three months. Horn's index scores were calculated for each patient on the day of the positive toxin test for C. difficile, and used to stratify differences in outcome variables (length of hospital stay, mortality and hospital costs). Eighty-five CDI patients (50% male, 64% Caucasian) were recruited. Discharge mortality was 0% for patients with Horn's index scores of 1 or 2, 5% for those with a score of 3, and 50% for those with a score of 4 (P < 0.001). Three-month mortality was 0%, 5%, 17% and 60% for patients with Horn's index scores of 1, 2, 3 and 4, respectively (P = 0.0004). Median three-month hospital costs were $8,585, $12,670, $29,077 and $68,708 for patients with Horn's index scores of 1, 2, 3 and 4, respectively (P < 0.001). Patients with Horn's index scores of 3 or 4 had a significantly longer hospital stay [mean 33.4 (standard deviation, SD 33.3) days] than patients with scores of 1 or 2 [mean 15.1 (SD 16.2) days, P = 0.001]. This study found Horn's index to be a simple and useful method for identifying CDI patients at high risk of poor clinical and economic outcomes.

Fidaxomicin for the Treatment of Clostridium Difficile Infection in the Pediatric Population - Not Quite So Soon Yet

Fidaxomicin is a new narrow spectrum macrocyclic antibiotic. It inhibits bacterial RNA polymerase and eradicates C difficile with minimal effect on normal intestinal flora. The US FDA granted orphan drug designation for all formulations of fidaxomicin for the treatment of C difficile infections in pediatric patients on January 10, 2011. Fidaxomicin has bactericidal activity against C difficile with a prolonged post-antibiotic effect. Even though this medication has an orphan designation for pediatrics, all the available pharmacokinetic and pharmacodynamic data were in subjects ≥ 18 years old. The MIC₉₀ for fidaxomicin against C. difficile varies from 0.0078 to 0.25 mcg/ml. Fidaxomicin is poorly absorbed. The highest peak plasma concentration in patients treated with fidaxomicin was 0.191 mcg/ml. Fecal levels of fidaxomicin after oral administration are extremely high. The average fecal concentrations in C difficile patients were 255.6 mcg/g, 441.7 mcg/g, and 1443.3 mcg/g in the 100, 200, and 400 mg/day groups, respectively. At a dose of 400 mg/day the average fecal concentration was 5700 times higher than the highest MIC₉₀ of fidaxomicin against C difficile. In a phase III clinical trial fidaxomicin 200 mg twice daily was compared with vancomycin 125 mg four times per day orally for 10 days. Only two patients were 18 years old, and no patients younger than 18 years old participated in the study. The rates of clinical cure with fidaxomicin were noninferior to those with vancomycin. Patients who were infected with non-North American Pulsed Field type 1 strains had fewer recurrences in the fidaxomicin group than patients in the vancomycin group. Side effects were similar between both therapies. Most patients experienced mild gastro-intestinal symptoms. Fidaxomicin is a good therapeutic alternative to vancomycin and metronidazole, especially in patients with recurrence of C difficile infection. Patients rarely experience systemic side effects which improves compliance. The dose of fidaxomicin is expected to be 200 mg given orally twice a day for patients 16 years and older. At this point, Optimer Pharmaceuticals Inc has conducted clinical trials in adults only. Additional clinical trials in pediatric patients are needed before therapeutic recommendations can be made in this population.

Prevalence and clinical course of Clostridium difficile infection in a tertiary-care hospital: a retrospective analysis

The spectrum of Clostridium difficile-associated diarrhea (CDAD) is changing. Apart from antibiotic use, other risk factors such as use of proton pump inhibitors (PPI) and immunosuppressive agents, intensive care unit (ICU) stay and inflammatory bowel disease are being recognized. We retrospectively analyzed data on patients whose stool samples were tested for C. difficile toxin (CDT) by enzyme linked immunosorbent assay between June 2006 and May 2008. Demographic and clinical data, and risk factors (antibiotic use, underlying malignancy, chemotherapy, use of PPI, ICU stay) were noted. The details of treatment for CDAD, response, complication and follow up were recorded. Patients whose stool samples were CDT-positive were grouped as study subjects and those with negative stool samples were included in the control group. Of the 99 patients (mean age 46.7 years; 58 men) whose stool samples were tested during this period, 17 (17%) were positive for CDT. As compared with control subjects (n = 82), study subjects were more likely to have fever, prolonged ICU stay, underlying malignancy, and exposure to immunosuppressive and chemotherapeutic agents. On multivariate analysis, exposure to immunosuppressive agents was the only risk factor associated with CDAD. Fifteen patients were treated with metronidazole and two with vancomycin. Two patients did not respond to metronidazole but responded to vancomycin. No patient developed any complication. The prevalence of C. difficile toxin in diarrheal stools sent for C. difficile toxin testing was 17%. Exposure to immunosuppressive agents was a risk factor for the infection. Metronidazole was effective in a majority of patients.

Fecal flora reconstitution for recurrent Clostridium difficile infection: results and methodology

GOALS

Recurrent Clostridium difficile infection (RCDI) is an increasingly common clinical problem without ideal treatment options. Our aim was to evaluate our results using Fecal Flora Reconstitution (FFR), and promulgate our methodology to the GI community to foster its more widespread use in appropriate candidates.

BACKGROUND

FFR, sometimes termed "fecal transplantion" has been shown in numerous reports to be an effective treatment of RCDI, however, most of these studies have small sample sizes and few focus specifically on the methodology used in colonoscopic preparation and delivery of donated stool.

STUDY

Nineteen patients with confirmed multiply recurrent CDI were treated by infusing donor stool through a colonoscope.

RESULTS

Out of 19 patients, 18 initially responded to treatment with a single FFR treatment, 1 patient responded after a second FFR infusion. All 19 patients maintained prolonged cured status followed until submission, ranging from 6 months to 5 years. Three patients were presumed reinfected after remaining symptom free for a period spanning from 6 months to 4 years. These patients tested positive for C. difficile after prescription of additional antibiotics for unrelated infections.

CONCLUSIONS

Fecal Flora Reconstitution is an effective, viable, and simple method of treatment for the difficult to treat patients with RCDI who fail standard therapy.

Systematic review and meta-analysis of Saccharomyces boulardii in adult patients

This article reviews the evidence for efficacy and safety of Saccharomyces boulardii (S. boulardii) for various disease indications in adults based on the peer-reviewed, randomized clinical trials and pre-clinical studies from the published medical literature (Medline, Clinical Trial websites and meeting abstracts) between 1976 and 2009. For meta-analysis, only randomized, blinded controlled trials unrestricted by language were included. Pre-clinical studies, volunteer studies and uncontrolled studies were excluded from the review of efficacy and meta-analysis, but included in the systematic review. Of 31 randomized, placebo-controlled treatment arms in 27 trials (encompassing 5029 study patients), S. boulardii was found to be significantly efficacious and safe in 84% of those treatment arms. A meta-analysis found a significant therapeutic efficacy for S. boulardii in the prevention of antibiotic-associated diarrhea (AAD) (RR = 0.47, 95% CI: 0.35-0.63, P < 0.001). In adults, S. boulardii can be strongly recommended for the prevention of AAD and the traveler's diarrhea. Randomized trials also support the use of this yeast probiotic for prevention of enteral nutrition-related diarrhea and reduction of Helicobacter pylori treatment-related symptoms. S. boulardii shows promise for the prevention of C. difficile disease recurrences; treatment of irritable bowel syndrome, acute adult diarrhea, Crohn's disease, giardiasis, human immunodeficiency virus-related diarrhea; but more supporting evidence is recommended for these indications. The use of S. boulardii as a therapeutic probiotic is evidence-based for both efficacy and safety for several types of diarrhea.

Economic healthcare costs of Clostridium difficile infection: a systematic review

Clostridium difficile infection (CDI) is the leading cause of infectious diarrhoea in hospitalised patients. CDI increases patient healthcare costs due to extended hospitalisation, re-hospitalisation, laboratory tests and medications. However, the economic costs of CDI on healthcare systems remain uncertain. The purpose of this study was to perform a systematic review to summarise available studies aimed at defining the economic healthcare costs of CDI. We conducted a literature search for peer-reviewed studies that investigated costs associated with CDI (1980 to present). Thirteen studies met inclusion and exclusion criteria. CDI costs in 2008 US dollars were calculated using the consumer price index. The total and incremental costs for primary and recurrent CDI were estimated. Of the 13, 10 were from the USA and one each from Canada, UK, and Ireland. In US-based studies incremental cost estimates ranged from $2,871 to $4,846 per case for primary CDI and from $13,655 to $18,067 per case for recurrent CDI. US-based studies in special populations (subjects with irritable bowel disease, surgical inpatients, and patients treated in the intensive care unit) showed an incremental cost range from $6,242 to $90,664. Non-US-based studies showed an estimated incremental cost of $5,243 to $8,570 per case for primary CDI and $13,655 per case for recurrent CDI. Economic healthcare costs of CDI were high for primary and recurrent cases. The high cost associated with CDI justifies the use of additional resources for CDI prevention and control.

Evidence-based review of probiotics for antibiotic-associated diarrhea and Clostridium difficile infections

Probiotics are living microbes taken to confer a health benefit on the host. Although probiotics have a long history of use in Europe and Asia and have been on the U.S. market for over 14 years, there is still confusion about how to effectively use them. The use of probiotics for the prevention of antibiotic-associated diarrhea (AAD) and the treatment of Clostridium difficile infections (CDI) has been tested in randomized controlled clinical trials. This paper will review the evidence supporting probiotic therapy for these two diseases and also review the advantages and disadvantages of probiotics. The advantages of probiotic therapy include multiple mechanisms of action against pathogens, the ability to interact with the host's natural defense systems, survival to the target organ and a good risk to benefit ratio. Disadvantages of probiotics include lack of standardization for clinical trial designs, variations in regulatory standards, poor quality control for some products and infrequent serious adverse reactions. Overall, probiotics offer a promising strategy for the prevention and treatment for AAD and CDI.

Faecal incontinence in older people

Faecal incontinence in older people is a distressing and socially isolating symptom and increases the risk of morbidity, mortality and dependency. Many older individuals with faecal incontinence will not volunteer the problem to their general practitioner or nurse and, regrettably, health care providers do not routinely enquire about the symptom. Even when older people are noted by health care professionals to have faecal incontinence, the condition is often managed passively, especially in the long-term care setting where it is most prevalent. The importance of identifying treatable causes of faecal incontinence in older people, rather than just managing passively, is strongly emphasized in national and international guidance, but audit shows that adherence to such guidance is generally poor. This article describes epidemiology, causes, assessment, diagnosis and treatment of faecal incontinence in older people.

Quasiexperimental study of the effects of antibiotic use, gastric acid-suppressive agents, and infection control practices on the incidence of Clostridium difficile-associated diarrhea in hospitalized patients

The objective of this study was to evaluate the effects of antimicrobial drug use, gastric acid-suppressive agent use, and infection control practices on the incidence of Clostridium difficile-associated diarrhea (CDAD) in a 426-bed general teaching hospital in Northern Ireland. The study was retrospective and ecological in design. A multivariate autoregressive integrated moving average (time-series analysis) model was built to relate CDAD incidence with antibiotic use, gastric acid-suppressive agent use, and infection control practices within the hospital over a 5-year period (February 2002 to March 2007). The findings of this study showed that temporal variation in CDAD incidence followed temporal variations in expanded-spectrum cephalosporin use (average delay = 2 months; variation of CDAD incidence = 0.01/100 bed-days), broad-spectrum cephalosporin use (average delay = 2 months; variation of CDAD incidence = 0.02/100 bed-days), fluoroquinolone use (average delay = 3 months; variation of CDAD incidence = 0.004/100 bed-days), amoxicillin-clavulanic acid use (average delay = 1 month; variation of CDAD incidence = 0.002/100 bed-days), and macrolide use (average delay = 5 months; variation of CDAD incidence = 0.002/100 bed-days). Temporal relationships were also observed between CDAD incidence and use of histamine-2 receptor antagonists (H2RAs; average delay = 1 month; variation of CDAD incidence = 0.001/100 bed-days). The model explained 78% of the variance in the monthly incidence of CDAD. The findings of this study highlight a temporal relationship between certain classes of antibiotics, H2RAs, and CDAD incidence. The results of this research can help hospitals to set priorities for restricting the use of specific antibiotic classes, based on the size-effect of each class and the delay necessary to observe an effect.

Review of current literature on the economic burden of Clostridium difficile infection

Clostridium difficile is well recognized as the most common infectious cause of healthcare-associated diarrhea. Since 2000, this pathogen has demonstrated an increased propensity to cause more frequent and virulent illness that is often refractory to treatment. An analysis by the Centers for Disease Control and Prevention revealed that, in the United States, the number of patients discharged from hospitals who received the International Classification of Diseases, Ninth Revision discharge diagnosis code for C. difficile infection (CDI) more than doubled from 2000 to 2003. Unpublished data indicate that this trend has continued and that more than 250,000 US hospitalizations were associated with CDI in 2005. A previously uncommon hypervirulent strain of C. difficile is thought to contribute, in part, to the dramatic increase in the incidence and severity of the infection. Although the economic impact of the disease is believed to be profound and is expected to increase, data on the costs associated with CDI are scarce. To more completely assess its economic burden, we performed a review of available literature that reported costs associated with the infection.

Gastric acid suppression by proton pump inhibitors as a risk factor for clostridium difficile-associated diarrhea in hospitalized patients

BACKGROUND

Evidence for the association between Clostridium difficile (C. difficile) and the use of proton pump inhibitor (PPI) is unclear. This study investigated the relationship between Clostridium difficile-associated diarrhea (CDAD) and exposure to acid suppressive therapy in hospitalized adult patients while controlling for the most common predisposing risk factors.

METHODS

A retrospective case-control study was conducted at a local hospital of all hospitalized patients between October 1, 2005 and September 30, 2006 who developed CDAD during hospitalization. Subjects were determined to have CDAD if there was a positive C. difficile toxin and clinical correlation of diarrhea at the time of diagnosis. Subjects were pair-matched to controls on the following factors: admission date, antibiotic exposure, gender, age groups, patient location (medical or surgical unit), and room type at time of admission. Seven risk factors were assessed for association with onset of CDAD: exposure to PPIs or H(2)-blockers, renal failure, diabetes mellitus, immunosuppression, malignancy, and gastrointestinal disease.

RESULTS

Ninety-four cases were successfully matched to controls. Cases were more likely than controls to receive acid suppressive therapy during hospitalization, 72 (76.6%) versus 40 (42.6%), respectively, P= 0.030. In a multivariate exact conditional logistic regression analysis, CDAD was associated with use of PPI (odds ratio [OR]= 3.6, 95% confidence interval [CI]= 1.7-8.3; P < 0.001), and with renal failure (OR = 5.7, CI = 1.3-39.1; P= 0.02).

CONCLUSION

This study showed elevated risk of developing CDAD in hospitalized patients with acid suppressive therapy, especially when PPIs were used.

Defining surgical therapy for pseudomembranous colitis with toxic megacolon

BACKGROUND

Pseudomembranous colitis has increased in incidence and severity over the past 10 years. Toxic megacolon is a rare but reported presentation of severe pseudomembranous colitis. This article reviews the reported cases of Clostridium difficile with toxic megacolon in the literature and introduces an additional case that underscores the importance of early diagnosis in guiding appropriate therapy.

METHODS

A systematic review of the literature was performed to identify previous reports of pseudomembranous colitis presenting with toxic megacolon, and the outcomes of each of these cases was analyzed. The review was focused on atypical presentations in immunocompromised patients.

RESULTS

Seventeen cases of C. difficile colitis presenting as toxic megacolon were identified. The overall mortality rate was 50% (9/18). Fifteen patients underwent surgery with an associated mortality rate of 50%. Thirteen patients had a subtotal colectomy. Seven of the patients (39%) were taking immunosuppressant medications, and 5 (28%) patients presented with atypical symptoms. Three (76%) of those were immunosuppressed. In several cases, failure to make an early diagnosis of C. difficile colitis resulted in a worse outcome because appropriate therapy was delayed.

CONCLUSIONS

Toxic megacolon is well-established as an unusual presentation of C. difficile colitis. These patients are less likely to present with typical symptoms such as diarrhea or typical risk factors like recent administration of antibiotics, so diagnosis can be a challenge. A patient presenting with toxic megacolon without a history of inflammatory bowel disease should be assumed to have C. difficile colitis until proven otherwise, and medical or surgical therapy administered accordingly.

Comparative efficacies of rifaximin and vancomycin for treatment of Clostridium difficile-associated diarrhea and prevention of disease recurrence in hamsters

Clostridium difficile-associated colitis is an increasing cause of morbidity and mortality in hospitalized patients, with high relapse rates following conventional therapy. We sought to determine the efficacy of rifaximin, a novel nonabsorbed antibiotic, in the hamster model of C. difficile-associated diarrhea (CDAD). Hamsters received clindamycin subcutaneously and 24 h later were infected by gavage with one of two C. difficile strains: a reference strain (VPI 10463) and a current epidemic strain (BI17). Vancomycin (50 mg/kg of body weight) or rifaximin (100, 50, and 25 mg/kg) were then administered orally for 5 days beginning either on the same day as infection (prevention) or 24 h later (treatment). Therapeutic effects were assessed by weight gain, histology, and survival. We found that rifaximin was as effective as vancomycin in the prevention and treatment of colitis associated with the two C. difficile strains that we examined. There was no relapse after treatment with vancomycin or rifaximin in hamsters infected with the BI17 strain. Hamsters infected with the VPI 10463 strain and treated with rifaximin did not develop relapsing infection within a month of follow-up, whereas the majority of vancomycin-treated animals relapsed (0% versus 75%, respectively; P < 0.01). In conclusion, rifaximin was found to be an effective prophylactic and therapeutic agent for CDAD in hamsters and was not associated with disease recurrence. These findings, in conjunction with the pharmacokinetic and safety profiles of rifaximin, suggest that it is an attractive candidate for clinical use for CDAD.

Active immunization of hamsters against Clostridium difficile infection using surface-layer protein

Clostridium difficile is the leading cause of infectious antibiotic-associated diarrhoea, particularly among the elderly. Its surface-layer protein (SLP) was tested as a vaccine component in a series of immunization and challenge experiments with Golden Syrian hamsters, combined with different systemic and mucosal adjuvants. Some regimens were also tested in a nonchallenge BALB/c mouse model, enabling closer monitoring of the immune response. None of the regimens conferred complete protection in the hamster model, and antibody stimulation was variable within regimens, and generally modest or poor. Mice displayed stronger antibody responses to SLP compared with hamsters. Two hamsters of five given SLP with Ribi (monophosphoryl lipid A and synthetic trehalose dicorynomycolate) survived the challenge, as did two of three given SLP with Ribi and cholera toxin. This modest trend to protection is interpreted with caution, because the survivors had low anti-SLP serum antibody titres. The hamsters were an outbred line, and subject to more genetic variability than inbred animals; however, BALB/c mice also showed strongly variable antibody responses. There is a clear need for better adjuvants for single-component vaccines, particularly for mucosal delivery. The hamster challenge model may need to be modified to be useful in active immunization experiments with SLP.

Is It Clostridium difficile Infection or Something Else? A Case-control Study of 352 Hospitalized Patients With New-onset Diarrhea

BACKGROUND

Clostridium difficile-associated diarrhea (CDAD) is a leading cause of nosocomial diarrhea in the United States, and may be associated with significant morbidity and occasional mortality. Diarrhea is also very common among hospitalized patients and is often related to a variety of factors not related to C difficile infection.

METHODS

We performed a retrospective case-control study at a tertiary care community medical center to delineate factors that are predictive of CDAD among hospitalized patients with new-onset diarrhea (ie, not present at the time of admission). Controls were selected based on negative C difficile toxin test(s) (CDTTs) (> 95% by cytotoxic assay), presence on the same ward as the patients with first positive CDTT, and hospitalization around the same period as the positive cases.

RESULTS

The study involved 352 patients (88 cases and 264 controls). In univariate analysis, age 75 years or greater, exposure to cefazolin or levofloxacin during the 4-week period preceding CDTT, and hospitalization for 7 days or greater before CDTT were significantly associated with a positive test; male gender and prior ceftriaxone exposure nearly reached statistical significance. Multivariate logistic regression analysis revealed age 75 years or greater (odds ratio [OR] 2.2, 95% confidence interval [CI] 1.3-3.7), hospitalization for 7 days or more (OR 2.3, 95% CI 1.3-3.8], and prior exposure to cefazolin (OR 3.5, 95% CI 1.6-7.5) or levofloxacin (OR 2.1, 95% CI 1.2-3.7) as independent predictors of a positive CDTT; male gender nearly achieved statistical significance (OR 1.6, 95% CI 0.9-2.7).

CONCLUSIONS

Among hospitalized patients with diarrhea who underwent testing for C difficile toxin, age 75 years or older, hospitalization for 7 days or greater, and recent exposure to cefazolin or levofloxacin were important predictors of a positive CDTT. These findings may help in the initiation of early presumptive treatment for CDAD, and appropriate isolation of higher risk patients before results become available. In addition, consideration of these risk factors may help in deciding whether a CDTT should be repeated when the first test is negative. Our study also supports more judicious use of antibiotics, particularly cefazolin and levofloxacin, in reducing the risk of CDAD in hospitalized patients.

Implications of the changing face of Clostridium difficile disease for health care practitioners

Recent reported outbreaks of Clostridium difficile-associated disease in Canada have changed the profile of C difficile infections. Historically, C difficile disease was thought of mainly as a nosocomial disease associated with broad-spectrum antibiotics, and the disease was usually not life threatening. The emergence of an epidemic strain, BI/NAP1/027, which produces a binary toxin in addition to the 2 classic C difficile toxins A and B and is resistant to some fluoroquinolones, was associated with large numbers of cases with high rates of mortality. Recently, C difficile has been reported more frequently in nonhospital-based settings, such as community-acquired cases. The C difficile disease is also being reported in populations once considered of low risk (children and young healthy women). In addition, poor response to metronidazole treatment is increasing. Faced with an increasing incidence of C difficile infections and the changing profile of patients who become infected, this paper will reexamine the current concepts on the epidemiology and treatment of C difficile-associated disease, present new hypotheses for risk factors, examine the role of spores in the transmission of C difficile, and provide recommendations that may enhance infection control practices.

Proton pump inhibitor therapy is a risk factor for Clostridium difficile-associated diarrhoea

BACKGROUND

Inhibition of gastric acid removes a defence against ingested bacteria and spores, increasing the risk of some forms of gastroenteritis. Previous studies investigating a possible link between acid suppression therapy and Clostridium difficile-associated diarrhoea have reported conflicting results.

AIM

To investigate whether acid suppression therapy is associated with an increased risk of C. difficile-associated diarrhoea. Prospective case-control study of 155 consecutive in-patients with C. difficile-associated diarrhoea.

RESULTS

Antibiotics had been received by 143 (92%) of the C. difficile-associated diarrhoea group and 76 (50%) of the controls during the preceding 3 months. Among those receiving antibiotics, 59 (41%) of the C. difficile-associated diarrhoea group had also received acid suppression, compared with 21 (28%) of controls (OR 1.84, CI 1.01, 3.36, chi(2) = 4.0, P = 0.046). Among the entire C. difficile-associated diarrhoea group 64 (41%) had received acid suppression compared with 40 (26%) of controls (OR 1.99, CI 1.19, 3.31, chi(2) = 7.9, P = 0.005). Logistic regression analyses found that C. difficile-associated diarrhoea was independently associated with: antibiotic use (OR 13.1, 95% CI: 6.6, 26.1); acid suppression therapy (OR 1.90, 95% CI: 1.10, 3.29); and female sex (OR 1.79, 95% CI: 1.06, 3.04).

CONCLUSIONS

The risk of C. difficile-associated diarrhoea in hospitalized patients receiving antibiotics may be compounded by exposure to proton pump inhibitor therapy.

Meta-analysis of probiotics for the prevention of antibiotic associated diarrhea and the treatment of Clostridium difficile disease

CONTEXT

Antibiotic-associated diarrhea (AAD) is a common complication of most antibiotics and Clostridium difficile disease (CDD), which also is incited by antibiotics, is a leading cause of nosocomial outbreaks of diarrhea and colitis. The use of probiotics for these two related diseases remains controversial.

OBJECTIVE

To compare the efficacy of probiotics for the prevention of AAD and the treatment of CDD based on the published randomized, controlled clinical trials.

DATA SOURCES

PubMed, Medline, Google Scholar, NIH registry of clinical trials, metaRegister, and Cochrane Central Register of Controlled Trials were searched from 1977 to 2005, unrestricted by language. Secondary searches of reference lists, authors, reviews, commentaries, associated diseases, books, and meeting abstracts.

STUDY SELECTION

Trials were included in which specific probiotics given to either prevent or treat the diseases of interest. Trials were required to be randomized, controlled, blinded efficacy trials in humans published in peer-reviewed journals. Trials that were excluded were pre-clinical, safety, Phase 1 studies in volunteers, reviews, duplicate reports, trials of unspecified probiotics, trials of prebiotics, not the disease being studied, or inconsistent outcome measures. Thirty-one of 180 screened studies (totally 3,164 subjects) met the inclusion and exclusion criteria.

DATA EXTRACTION

One reviewer identified studies and abstracted data on sample size, population characteristics, treatments, and outcomes.

DATA SYNTHESIS

From 25 randomized controlled trials (RCTs), probiotics significantly reduced the relative risk of AAD (RR = 0.43, 95% CI 0.31, 0.58, p < 0.001). From six randomized trials, probiotics had significant efficacy for CDD (RR = 0.59, 95% CI 0.41, 0.85, p = 0.005).

CONCLUSION

A variety of different types of probiotics show promise as effective therapies for these two diseases. Using meta-analyses, three types of probiotics (Saccharomyces boulardii, Lactobacillus rhamnosus GG, and probiotic mixtures) significantly reduced the development of antibiotic-associated diarrhea. Only S. boulardii was effective for CDD.

Prevalence and characteristics of bacteria and host factors in an outbreak situation of antibiotic-associated diarrhoea

Antibiotic-associated diarrhoea (AAD) represents a clinical entity leading to prolonged hospital stays and diagnostic and therapeutic procedures, and results in additional costs. The aim of the present study was to assess the prevalence and characteristics of different bacteria in stools of patients with AAD. The reliability of diagnostic procedures under routine conditions was evaluated. Host factors were also analysed. From June 2002 to April 2003 89 cases of diarrhoea were reported at a hospital unit for internal medicine. Clostridium difficile and Clostridium perfringens toxin enzyme-immunoassays (EIAs), and culture for C. difficile, C. perfringens and Staphylococcus aureus were performed on stool samples from all patients. Toxin production was determined in isolated S. aureus strains. In vitro susceptibility of S. aureus for oxacillin and of C. difficile for vancomycin, metronidazole, linezolid, fusidic acid and tetracycline was tested. Host factors, such as age, comorbidities, antibiotic exposure and contact with other patients, were evaluated. Twenty-six stools were positive for C. difficile toxins by an EIA technique, while C. difficile was cultured from 39. C. difficile was isolated from 21 stools that were EIA negative. Additionally, from 28 stools S. aureus and/or C. perfringens could be isolated. Nine samples contained only S. aureus and/or C. perfringens. Thirty-one stools were negative in all tests. All C. difficile isolates were susceptible to vancomycin and metronidazole. Age >60 years, and diseases of the vascular system, the heart, the kidneys and the lungs were identified as risk factors for acquiring C. difficile in this setting (P values < 0.05). Stool culture for C. difficile was shown to be more sensitive than toxin EIA in this study. Risk factors for the acquisition of C. difficile in outbreak situations seem to differ from risk factors in the normal hospital setting. The role of toxin-producing S. aureus in cases of AAD needs further investigation.

[Risk factors for nosocomial Clostridium difficile diarrhoea in an infectious and tropical diseases department]

FOREWORD

Clostridium difficile associated diarrhea (CDAD) accounts for 25% of all cases of diarrhea occurring in hospital. Infectious diseases departments are considered as presenting with an important risk of CDAD because of the large quantity of antibiotics used.

OBJECTIVES AND METHOD

The authors made a prospective study in the first 6 months of 2001, in order to identify the risk factors of CDAD in their department. One hundred and fifty-two patients hospitalized for at least 6 days were included in this study. The studied factors were: age, mean number of days of hospitalization (MDH), antibiotic therapy, WHO scale of reduced mobility of patients, recent hospitalization (less than 3 months before).

RESULTS

MDH was 36 (IC95%: 23-48). Beta-lactam antibiotics were found as significant risk factors, as reported in the literature. However, age and a recent hospitalization were not related to the CDAD as described in the literature. A reduced mobility of patients was identified as a significant risk factor for developing a CDAD in our department.