Clostridium difficile-associated diarrhea and colitis

Adherence to and Outcomes Associated with a Clostridium difficile Guideline at a Large Teaching Institution

PURPOSE

The incidence and virulence of Clostridium difficile infection (CDI) has recently increased. National CDI treatment guidelines stratify patients based on clinical symptoms and recommend treatment based on severity of illness. In 2009, Advocate Lutheran General Hospital (Park Ridge, Illinois) adopted guidelines with treatment algorithms identical to the national guidelines. The purpose of this study was to determine whether patients were being treated in accordance with the CDI guidelines and whether adherence impacted patient outcomes.

METHODS

This was a retrospective, descriptive study. Subjects were identified by CDI-associated ICD-9 codes from July 1, 2009 to June 30, 2011 and stratified by disease severity. Guideline adherence was assessed based on initial treatment selection, and subjects were then further categorized as undertreated (UT), overtreated (OT), or appropriately treated (AT). Secondary endpoints included need for therapy escalation, clinical cure, recurrence rates, 90-day all-cause mortality, proton pump inhibitor (PPI), and antimicrobial use.

RESULTS

Two hundred fifty subjects totaling 324 encounters were analyzed. Overall guideline adherence was 42.9%. Adherence rates by CDI severity were mild-moderate, 53.9%; severe, 39.0%; and severe-complicated, 17.9% (P < .001). Of all the subjects, 42.9% were AT, 30.9% were OT, and 26.2% were UT. Clinical outcomes between UT versus AT subjects were as follows: therapy escalation required, 34.1% versus 27.5% (P = .289); clinical cure, 41.2% versus 55.7% (P = .033); mortality, 24.7% versus 10.1% (P = .003); and recurrence, 44.7% versus 24.8% (P < .02). Clinical outcomes between AT versus OT subjects were as follows: therapy escalation required 27.5% versus 14.4% (P < .02); clinical cure, 55.7% versus 66.7% (P = .089); mortality, 10.1% versus 7.8% (P = .553); recurrence, 24.8% versus 27.8% (P = .871).

CONCLUSIONS

The majority of subjects were not treated according to CDI guidelines, particularly those with severe and severe-complicated disease. UT subjects had worse clinical outcomes and OT subjects failed to show significant improvements in clinical outcomes compared to AT subjects. Emphasis should be placed on CDI guideline adherence as this may be associated with improved outcomes.

Synthetic polymers active against Clostridium difficile vegetative cell growth and spore outgrowth

Nylon-3 polymers (poly-β-peptides) have been investigated as synthetic mimics of host-defense peptides in recent years. These polymers are attractive because they are much easier to synthesize than are the peptides themselves, and the polymers resist proteolysis. Here we describe in vitro analysis of selected nylon-3 copolymers against Clostridium difficile, an important nosocomial pathogen that causes highly infectious diarrheal disease. The best polymers match the human host-defense peptide LL-37 in blocking vegetative cell growth and inhibiting spore outgrowth. The polymers and LL-37 were effective against both the epidemic 027 ribotype and the 012 ribotype. In contrast, neither vancomycin nor nisin inhibited outgrowth for the 012 ribotype. The best polymer was less hemolytic than LL-37. Overall, these findings suggest that nylon-3 copolymers may be useful for combatting C. difficle.

Assessing control bundles for Clostridium difficile: a review and mathematical model

Clostridium difficile is the leading cause of infectious diarrhea in hospitalized patients. Integrating several infection control and prevention methods is a burgeoning strategy for reducing disease incidence in healthcare settings. We present an up-to-date review of the literature on ‘control bundles' used to mitigate the transmission of this pathogen. All clinical studies of control bundles reported substantial reductions in disease rates, in the order of 33%–61%. Using a biologically realistic mathematical model we then simulated the efficacy of different combinations of the most prominent control methods: stricter antimicrobial stewardship; the administering of probiotics/intestinal microbiota transplantation; and improved hygiene and sanitation. We also assessed the health gains that can be expected from reducing the average length of stay of inpatients. In terms of reducing the rates of colonization, all combinations had the potential to give rise to marked improvements. For example, halving the number of inpatients on broad-spectrum antimicrobials combined with prescribing probiotics or intestinal microbiota transplantation could cut pathogen carriage by two-thirds. However, in terms of symptomatic disease incidence reduction, antimicrobials, probiotics and intestinal microbiota transplantation proved substantially less effective. Eliminating within-ward transmission by improving sanitation and reducing average length of stay (from six to three days) yielded the most potent symptomatic infection control combination, cutting rates down from three to less than one per 1000 hospital bed days. Both the empirical and theoretical exploration of C. difficile control combinations presented in the current study highlights the potential gains that can be achieved through strategically integrated infection control.

Is Clostridium difficile associated with the '4C' antibiotics? A retrospective observational study in diabetic foot ulcer patients

AIMS

Clostridium difficile is an anaerobic cytotoxin-producing bacterium that can cause infectious diarrhoea, pseudomembranous colitis and toxic megacolon. The major risk factors for developing C. difficile infection include recent or current antimicrobial use, diabetes, age over 65, proton pump inhibitor use, immunosuppression and previous infection with C. difficile. Most diabetic foot ulcers are polymicrobial.

METHODS

As a result guidelines advise treatment with broad spectrum antibiotics which include the '4C's' (clindamycin, cephalosporins, co-amoxiclav and ciprofloxacin) which are associated with a higher risk of C. difficile infection. Retrospective observational data (June 2008 to January 2012) for the diabetes foot ulcers were gathered from the Diabetes/Podiatry Clinic database in NHS Ayrshire and Arran and cross-matched with the NHS Ayrshire and Arran Microbiology database. There were 111 patients with mean age 59 years (range 24-94 years), 33 type 1 patients, 78 type 2 patients, mean duration of diabetes 16 years (6 months-37 years) and mean HbA1c 67 mmol/mol (54-108 mmol/mol) [8.3% (7.1-12%)].

RESULTS

The total number of days antimicrobials prescribed for all patients was 7938 (mean number of antimicrobial days per patient = 71.5 days). There was one case of C. difficile infection of 111 patients giving an incidence of 1.25 cases per 10,000 patient-days of antibiotics/1 case per 209 foot ulcers.

CONCLUSIONS

Large doses, numbers and greater duration of antibiotic therapy all result in a greater degree of normal gut flora depletion. It is possible that the alterations in gut flora in diabetic foot ulcer patients protect them from antibiotic-induced C. difficile overgrowth.

How do hospital professionals involved in a randomised controlled trial perceive the value of genotyping vs. PCR-ribotyping for control of hospital acquired C. difficile infections?

Background

Despite scientific advances in typing of C. difficile strains very little is known about how hospital staff use typing results during periods of increased incidence (PIIs). This qualitative study, undertaken alongside a randomised controlled trial (RCT), explored this issue. The trial compared ribotyping versus more rapid genotyping (MLVA or multilocus variable repeat analysis) and found no significant difference in post 48 hour cases (C difficile transmissions).

Methods

In-depth qualitative interviews with senior staff in 11/16 hospital trusts in the trial (5 MLVA and 6 Ribotyping). Semi-structured interviews were conducted at end of the trial period. Transcripts were content analysed using framework analysis supported by NVivo-8 software. Common sub-themes were extracted by two researchers independently. These were compared and organised into over-arching categories or ‘super-ordinate themes’.

Results

The trial recorded that 45% of typing tests had some impact on infection control (IC) activities. Interviews indicated that tests had little impact on initial IC decisions. These were driven by hospital protocols and automatically triggered when a PII was identified. To influence decision-making, a laboratory turnaround time < 3 days (ideally 24 hours) was suggested; MLVA turnaround time was 5.3 days. Typing results were predominantly used to modify initiated IC activities such as ward cleaning, audits of practice or staff training; major decisions (e.g. ward closure) were unaffected. Organisational factors could limit utilisation of MLVA results. Results were twice as likely to be reported as ‘aiding management’ (indirect benefit) than impacting on IC activities (direct effect). Some interviewees considered test results provided reassurance about earlier IC decisions; others identified secondary benefits on organisational culture. An underlying benefit of improved discrimination provided by MLVA typing was the ability to explore epidemiology associated with CDI cases in a hospital more thoroughly.

Conclusions

Ribotyping and MLVA are both valued by users. MLVA had little additional direct impact on initial infection control decisions. This would require reduced turnaround time. The major impact is adjustments to earlier IC measures and retrospective reassurance. For this, turnaround time is less important than discriminatory power. The potential remains for wider use of genotyping to examine transmission routes.

Progress in the discovery of treatments for C. difficile infection: A clinical and medicinal chemistry review

Clostridium difficile is an anaerobic, Gram-positive pathogen that causes C. difficile infection, which results in significant morbidity and mortality. The incidence of C. difficile infection in developed countries has become increasingly high due to the emergence of newer epidemic strains, a growing elderly population, extensive use of broad spectrum antibiotics, and limited therapies for this diarrheal disease. Because treatment options currently available for C. difficile infection have some drawbacks, including cost, promotion of resistance, and selectivity problems, new agents are urgently needed to address these challenges. This review article focuses on two parts: the first part summarizes current clinical treatment strategies and agents under clinical development for C. difficile infection; the second part reviews newly reported anti-difficile agents that have been evaluated or reevaluated in the last five years and are in the early stages of drug discovery and development. Antibiotics are divided into natural product inspired and synthetic small molecule compounds that may have the potential to be more efficacious than currently approved treatments. This includes potency, selectivity, reduced cytotoxicity, and novel modes of action to prevent resistance.

Clostridium difficile infection in the twenty-first century

Clostridium difficile is a spore-forming gram-positive bacillus, and the leading cause of antibiotic-associated nosocomial diarrhea and colitis in the industrialized world. With the emergence of a hypervirulent strain of C. difficile (BI/NAP1/027), the epidemiology of C. difficile infection has rapidly changed in the last decade. C. difficile infection, once thought to be an easy to treat bacterial infection, has evolved into an epidemic that is associated with a high rate of mortality, causing disease in patients thought to be low-risk. In this review, we discuss the changing face of C .difficile infection and the novel treatment and prevention strategies needed to halt this ever growing epidemic.

Clostridium difficile exposure as an insidious source of infection in healthcare settings: an epidemiological model

BACKGROUND

Clostridium difficile is the leading cause of infectious diarrhea in hospitalized patients. Its epidemiology has shifted in recent years from almost exclusively infecting elderly patients in whom the gut microbiota has been disturbed by antimicrobials, to now also infecting individuals of all age groups with no recent antimicrobial use.

METHODS

A stochastic mathematical model was constructed to simulate the modern epidemiology of C. difficile in a healthcare setting, and, to compare the efficacies of interventions.

RESULTS

Both the rate of colonization and the incidence of symptomatic disease in hospital inpatients were insensitive to antimicrobial stewardship and to the prescription of probiotics to expedite healthy gut microbiota recovery, suggesting these to be ineffective interventions to limit transmission. Comparatively, improving hygiene and sanitation and reducing average length of stay more effectively reduced infection rates. Although the majority of new colonization events are a result of within-hospital ward exposure, simulations demonstrate the importance of imported cases with new admissions.

CONCLUSIONS

By analyzing a wide range of screening sensitivities, we identify a previously ignored source of pathogen importation: although capturing all asymptomatic as well as symptomatic introductions, individuals who are exposed but not yet colonized will be missed by even a perfectly sensitive screen on admission. Empirical studies to measure the duration of this latent period of infection will be critical to assessing C. difficile control strategies. Moreover, identifying the extent to which the exposed category of individual contributes to pathogen importation should be explicitly considered for all infections relevant to healthcare settings.

Treatment of recurrent Clostridium difficile infection: a systematic review

BACKGROUND

Clostridium difficile infection (CDI) recurs in nearly one-third of patients who develop an initial infection. Recurrent CDI (RCDI) is associated with considerable morbidity, mortality, and cost. Treatment for RCDI has not been not well examined.

METHODS

A systematic review.

RESULTS

Sixty-four articles were identified evaluating eight different treatment approaches: metronidazole, vancomycin, fidaxomicin, nitazoxanide, rifampin, immunoglobulins, probiotics, and fecal bacteriotherapy. The meta-analysis found vancomycin to have a similar efficacy to metronidazole, although studies used varying doses and durations of therapy. Fidaxomicin was slightly more efficacious than vancomycin, though the number of studies was small. Good evidence for probiotics was limited. Fecal bacteriotherapy was found to be highly efficacious in a single randomized trial.

CONCLUSION

Metronidazole and vancomycin have good evidence for use in RCDI but heterogeneity in treatment duration and dose precludes robust conclusions. Fidaxomicin may have a role in treatment, but evidence is limited to subgroup analyses. Fecal bacteriotherapy was the most efficacious. Saccharomyces boulardii may have a role as adjunctive treatment.

Is colectomy for fulminant Clostridium difficile colitis life saving? A systematic review

AIM

It is unclear whether colectomy for fulminant Clostridium difficile colitis (FCDC) leads to a improvement in survival compared with continued medical therapy for this moribund population.

METHOD

Selected studies from 1994-2010 were identified through a comprehensive search theme applied to MEDLINE (OvidSP and PubMed), EMBASE and by hand searching. Data regarding mortality rates between medically and surgically treated patients were extracted. Risk of bias was assessed using a Newcastle-Ottawa Scale score. A meta-analysis of the odds ratios for mortality between surgical and medical treatment for FCDC was conducted using the Mantel-Haenszel method and fixed-effects modelling.

RESULTS

Five hundred and ten patients with FCDC were identified in six studies. The pooled adjusted odds ratio of mortality comparing surgery with medical therapy was 0.70 (0.49-0.99), suggesting that surgery provided a survival benefit.

CONCLUSION

Emergent colectomy for patients with FCDC provides a survival advantage compared with continuing antibiotics. Though there is selection bias of patients having surgery, the results of this systematic review suggest that colectomy has a therapeutic role in treating severe forms of C. difficile colitis.

Antibacterial effect of Manuka honey on Clostridium difficile

BACKGROUND

Manuka honey originates from the manuka tree (Leptospermum scoparium) and its antimicrobial effect has been attributed to a property referred to as Unique Manuka Factor that is absent in other types of honey. Antibacterial activity of Manuka honey has been documented for several bacterial pathogens, however there is no information on Clostridium difficile, an important nosocomial pathogen. In this study we investigated susceptibility of C. difficile to Manuka honey and whether the activity is bactericidal or bacteriostatic.

METHODS

Three C. difficile strains were subjected to the broth dilution method to determine minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) for Manuka honey. The agar well diffusion method was also used to investigate sensitivity of the C. difficile strains to Manuka honey.

RESULTS

The MIC values of the three C. difficile strains were the same (6.25% v/v). Similarly, MBC values of the three C. difficile strains were the same (6.25% v/v). The activity of Manuka honey against all three C. difficile strains was bactericidal. A dose-response relationship was observed between the concentrations of Manuka honey and zones of inhibition formed by the C. difficile strains, in which increasing concentrations of Manuka honey resulted in increasing size of zone of inhibition formed. Maximum zone of inhibition was observed at 50% (v/v) Manuka honey and the growth inhibition persisted over 7 days.

CONCLUSION

C. difficile is appreciably susceptible to Manuka honey and this may offer an effective way of treating infections caused by the organism.

Clostridium difficile-associated diarrhea in dialysis patients

BACKGROUND

Dialysis patients have impaired host defense mechanisms and frequently require antibiotics for various infective complications. In this study, we investigated whether dialysis patients have greater risk for Clostridium difficile-associated diarrhea (CDAD).

METHODS

During the 4-year study period (2004-2008), 85 patients with CDAD were identified based on a retrospective review of C difficile toxin assay or histology records. Nosocomial diarrheal patients without CDAD were considered as controls (n=403). We assessed the association between renal function and the prevalence and clinical outcomes of CDAD.

RESULTS

There was a significant difference in the prevalence rate of chronic kidney disease (CKD) between CDAD and non-CDAD patients (P<0.001). Sixteen patients (18.8%) of the CDAD group were treated with dialysis, whereas 21 patients (5.2%) of the non-CDAD group were treated with dialysis. There was a significant association between renal function and CDAD in patients on dialysis [odds ratio (OR)=4.44, 95% confidence interval (CI) 2.19-8.99, P<0.001], but not in patients with CKD stage 3-5 (OR=1.10, 95% CI 0.63-1.92, P=0.73). In multivariate analysis, CKD stage 5D was an independent risk factor for the development of CDAD (OR=13.36, 95% CI 2.94-60.67, P=0.001).

CONCLUSION

Our data indicate that dialysis patients might be at a greater risk of developing CDAD, which suggests that particular attention should be provided to CDAD when antibiotic treatment is administered to dialysis patients.

Pseudomembranous colitis due to Clostridium difficile as a cause of perineal necrotising fasciitis

Although rare, pseudomembranous colitis may be a cause of perineal necrotising fasciitis in a context of immunosuppression, as in the case we report. This origin must be quickly identified because the therapeutic management, especially surgery, is unlikely to be the same as usual. Similarly, antibiotic treatment is also a matter of discussion due to the potential deleterious role of antibiotics in pseudomembranous colitis.

The intestinal microbiota dysbiosis and Clostridium difficile infection: is there a relationship with inflammatory bowel disease?

Gut microbiota is a compilation of microorganisms dwelling in the entire mammalian gastrointestinal tract. They display a symbiotic relationship with the host contributing to its intestinal health and disease. Even a slight fluctuation in this equipoise may be deleterious to the host, leading to many pathological conditions like Clostridium difficile infection or inflammatory bowel disease (IBD). In this review, we focus on the role of microbial dysbiosis in initiation of C. difficile infection and IBD, and we also touch upon the role of specific pathogens, particularly C. difficile, as causative agents of IBD. We also discuss the molecular mechanisms activated by C. difficile that contribute to the development and exacerbation of gastrointestinal disorders.

Outcomes in patients tested for Clostridium difficile toxins

Clostridium difficile testing is shifting from toxin detection to C. difficile detection. Yet, up to 60% of patients with C. difficile by culture test negative for toxins and it is unclear whether they are infected or carriers. We reviewed medical records for 7046 inpatients with a C. difficile toxin test from 2005 to 2009 to determine the duration of diarrhea and rate of complications and mortality among toxin-positive (toxin+) and toxin- patients. Overall, toxin- patients had less severe diarrhea, fewer diarrhea days, and lower mortality (P < 0.001, all comparisons) than toxin+ patients. One toxin- patient (n = 1/6121; 0.02%) was diagnosed with pseudomembranous colitis, but there were no complications such as megacolon or colectomy for fulminant CDI among toxin- patients. These data suggest that C. difficile-attributable complications are rare among patients testing negative for C. difficile toxins. More studies are needed to evaluate the clinical significance of C. difficile detection in toxin- patients.

Using sensor networks to study the effect of peripatetic healthcare workers on the spread of hospital-associated infections

BACKGROUND

Super-spreading events, in which an individual with measurably high connectivity is responsible for infecting a large number of people, have been observed. Our goal is to determine the impact of hand hygiene noncompliance among peripatetic (eg, highly mobile or highly connected) healthcare workers compared with less-connected workers.

METHODS

We used a mote-based sensor network to record contacts among healthcare workers and patients in a 20-bed intensive care unit. The data collected from this network form the basis for an agent-based simulation to model the spread of nosocomial pathogens with various transmission probabilities. We identified the most- and least-connected healthcare workers. We then compared the effects of hand hygiene noncompliance as a function of connectedness.

RESULTS

The data confirm the presence of peripatetic healthcare workers. Also, agent-based simulations using our real contact network data confirm that the average number of infected patients was significantly higher when the most connected healthcare worker did not practice hand hygiene and significantly lower when the least connected healthcare workers were noncompliant.

CONCLUSIONS

Heterogeneity in healthcare worker contact patterns dramatically affects disease diffusion. Our findings should inform future infection control interventions and encourage the application of social network analysis to study disease transmission in healthcare settings.

Differential yield of pathogens from stool testing of nosocomial versus community-acquired paediatric diarrhea

OBJECTIVES

To evaluate the role of routine stool examination for all pathogens in paediatric nosocomial diarrhea (NAD) and community-acquired diarrhea (CAD) over a two-year period at Alberta Children's Hospital and current practices in other Canadian hospitals. A secondary objective was to characterize features that may predict NAD or CAD etiology.

STUDY DESIGN

Retrospective cohort study and telephone survey.

SETTING

Alberta Children's Hospital (retrospective review) and Canadian tertiary care paediatric centres (telephone survey).

METHODS

The health and microbiological records of all children with an admission or discharge diagnosis of diarrhea were reviewed using a standardized data collection form. In addition, a telephone survey of laboratories serving all paediatric hospitals in Canada was conducted using a standard questionnaire to obtain information about practices for screening for pathogens related to NAD.

RESULTS

Four hundred and thirty-four CAD episodes and 89 NAD episodes were identified. Overall, rotavirus and Clostridium difficile were the most commonly identified pathogens. Bacterial culture was positive in 10.6% CAD episodes tested, with Escherichia coli O157:H7 identified as the most common non-C difficile organism. In NAD, no bacteria were identified other than C difficile (toxin). Screening for ova and parasites had negligible yield. Viruses were more frequent in the winter months, while bacterial pathogens were more common in the summer and fall months. Over 50% of Canadian paediatric hospitals still routinely process NAD specimens similarly to CAD specimens.

CONCLUSIONS

There is a need for the re-evaluation of routine ova and parasite screening, and bacterial culture in nonoutbreak episodes of NAD in children.

Diarrhea recurrence in patients with Clostridium difficile-associated diarrhea: Role of concurrent antibiotics

OBJECTIVE

To monitor prospectively patients with Clostridium difficile-associated diarrhea (CAD) in a six hundred bed tertiary care hospital to determine which factors influenced the recurrence of the diarrhea.

DESIGN

A prospective, nonrandomized study. After an initial diagnosis of CAD, patients were interviewed, and each week stool samples and environmental samples were monitored for the presence of toxigenic C difficile for as long as the patients remained in hospital. The relationship of concurrent antibiotics, prolonged fecal excretion of organism or toxin, and environmental contamination was assessed.

PATIENTS

Over a two-and-a-half year period, 75 consecutive patients with CAD were selected and those who gave their written informed consent were enrolled. A control group to evaluate environmental contamination consisted of 75 patients with diarrhea not associated with C difficile.

RESULTS

Of the 75 CAD patients, 11 (14.7%) had a recurrence of their diarrhea. Diarrhea recurrence was associated with an increased rate of prolonged excretion of toxigenic organism and/or C difficile toxin(s) (nine of 11 [81.8%] compared with nine of 64 [14.1%]; P≤0.0001; relative risk 14.25; 95% CI 3.383 to 60.023). The risk of diarrhea recurrence was not related to a specific antibiotic but to concurrent therapy. Treatment within 30 days of initial CAD-specific treatment with an antibiotic other than metronidazole or vancomycin occurred significantly more frequently in patients with recurrence of diarrhea compared with those who did not have a recurrence (eight of 11 [72.7%] compared with 22 of 64 [34.4%], P=0.022; relative risk 4; 95% CI 1.153 to 13.881). The environmental contamination rate for toxigenic C difficile in week one in the rooms of patients with diarrhea not caused by C difficile was low (two of 75 [2.6%]) compared with week one data for patients with CAD (14 of 75 [18.7%], P=0.002; relative risk 1.922; 95% CI 1.479 to 2.498). The most frequent site contaminated was the bedpan sprayer (eight of 14 [57.1%]). Pulsed field gel electrophoresis analysis of stool and environmental toxigenic isolates indicated that there was not a single endemic strain of C difficile.

CONCLUSIONS

This study indicates that the recurrence of diarrhea may be related to concurrent 'other' antibiotics. Although data indicated that there was a correlation between diarrhea recurrence and prolonged fecal excretion of toxin, further studies are required to clarify the clinical significance.

Association Between Use of Proton Pump Inhibitors and a Clostridium difficile-Associated Disease Outbreak: Case-Control Study

BACKGROUND

The use of proton pump inhibitors (PPIs) has been implicated as a potential contributor to the development of Clostridium difficile-associated disease (CDAD) because of the ability of these drugs to substantially reduce the bactericidal effect of gastric acid. This study focused on the impact of PPIs, among other known risk factors, during an outbreak of CDAD in a hospital setting.

OBJECTIVES

The primary objective was to determine whether there was an association between current use of a PPI and the CDAD outbreak. Secondary objectives were to evaluate any correlations between the CDAD outbreak and past use of PPIs, use of antibiotics, diabetes mellitus, enteral feeding, cancer, gastrointestinal surgery, inflammatory bowel disease, and previous care or residence in an institutional setting.

METHODS

A retrospective case-control study was conducted. One hundred and fifty cases of hospital-acquired Clostridium difficile were identified. Patients were individually matched to controls for age, sex, date of admission to hospital, and hospital unit. The groups were compared with respect to each exposure.

RESULTS

Eight case patients could not be matched with suitable controls. Therefore, data from 142 cases and 142 controls were analyzed. There was no association between current use of a PPI and the CDAD outbreak (odds ratio [OR] 1.0, 95% confidence interval [CI] 0.99-1.01). Similarly, there was no correlation between the CDAD outbreak and diabetes, enteral feeding, cancer, gastrointestinal surgery, inflammatory bowel disease, or previous care or residence in an institution. However, the development of CDAD was positively associated with use of antibiotics within the 30 days preceding the infection (OR 12.0, 95% CI 4.0-35.7) and with past use of a PPI (OR 2.4, 95% CI 1.4-4.3).

CONCLUSIONS

The development of CDAD during a hospital outbreak was associated with use of antibiotics and with past, not current, use of PPIs.

Efficacy of LFF571 in a hamster model of Clostridium difficile infection

LFF571 is a novel semisynthetic thiopeptide antibiotic with potent activity against a variety of Gram-positive pathogens, including Clostridium difficile. In vivo efficacy of LFF571 was compared to vancomycin in a hamster model of C. difficile infection (CDI). Infection was induced in Golden Syrian hamsters using a toxigenic strain of C. difficile. Treatment started 24 h postinfection and consisted of saline, vancomycin, or LFF571. Cox regression was used to analyze survival data from a cohort of animals evaluated across seven serial experimental groups treated with vancomycin at 20 mg/kg, LFF571 at 5 mg/kg, or vehicle alone. Survival was right censored; animals were not observed beyond day 21. At death or end of study, cecal contents were tested for C. difficile toxins A and B. In summary, the data showed that 5 mg/kg LFF571 decreased the risk of death by 79% (P < 0.0001) and 69% (P = 0.0022) compared with saline and 20 mg/kg vancomycin, respectively. Further analysis of the pooled data indicated that the survival benefit of LFF571 treatment at 5 mg/kg compared to vancomycin at 20 mg/kg was due primarily to a decrease in the risk of recurrence after end of treatment. Animals successfully treated with LFF571 or vancomycin had no detectable C. difficile toxin. Overall, LFF571 was more efficacious at the end of the study, at a lower dose, and with fewer recurrences, than vancomycin in the hamster model of CDI. LFF571 is being assessed in humans for safety and efficacy in the treatment of C. difficile infections.

Conservative surgical treatment for toxic megacolon due to Clostridium difficile infection in a transplanted pediatric patient

Severe disease caused by Clostridium difficile is frequently encountered in transplant recipients and carries a high mortality. Numerous studies have been published on this subject in the adult population, but few in the pediatric setting. A 4-year-old boy who had undergone heart transplant 20 months earlier was admitted to the pediatric intensive care unit after humoral rejection. Seven days after admission, he developed septic shock, abdominal distension, and paralytic ileus without diarrhea. Pseudomembranous colitis due to C. difficile was confirmed by microbiological and radiological studies. Despite treatment with rectal vancomycin and intravenous metronidazole, the patient did not improve and required decompressive laparotomy; because of the poor subsequent clinical course, terminal ileostomy and cecostomy were performed in a second operation. Recovery was satisfactory, and surgical reconstruction of intestinal tract was performed 3 months later without complications. Although early surgery with total colectomy is indicated, when there is a poor response to medical treatment in cases of C. difficile toxic megacolon, the case we present responded favorably to a conservative surgical approach that enabled intestinal integrity to be restored 3 months later. In the pediatric population, less aggressive therapeutic options should be considered, as they have benefits on the subsequent quality of life of the patient.

A Clostridium difficile infection "intervention": change in toxin assay results in fewer C difficile infection cases without changes in patient outcomes

BACKGROUND

Clostridium difficile infection (CDI) is most commonly diagnosed using toxin enzyme immunoassays (EIAs). A sudden decrease in CDI incidence was noted after a change in the EIA used at Barnes-Jewish Hospital in St Louis. The objective of this study was to determine whether the decreased CDI incidence related to the change in EIA resulted in adverse patient outcomes.

METHODS

Electronic hospital databases were used to collect data on demographics, outcomes, and treatment of inpatients who had a C difficile toxin assay performed between January 4, 2009, and April 3, 2009 (period A, preassay change) and between May 21, 2009, and August 17, 2009 (period B, postassay change).

RESULTS

Assays were positive in 240 of 1,221 patients (19.7%) during period A and in 106 of 1160 patients (9.1%) during period B (P < .01). There was no difference in mortality or discharge to hospice between the 2 periods (10.3% vs 10.1%; P = .90). Patients tested in period B were less likely to receive metronidazole or oral vancomycin (P < .01).

CONCLUSIONS

The new EIA resulted in fewer positive tests and reduced anti-CDI therapy. There was no difference in mortality between the 2 periods, suggesting that the decreased incidence was due to increased assay specificity, not decreased sensitivity.

Composition of the early intestinal microbiota: knowledge, knowledge gaps and the use of high-throughput sequencing to address these gaps

The colonization, development and maturation of the newborn gastrointestinal tract that begins immediately at birth and continues for two years, is modulated by numerous factors including mode of delivery, feeding regime, maternal diet/weight, probiotic and prebiotic use and antibiotic exposure pre-, peri- and post-natally. While in the past, culture-based approaches were used to assess the impact of these factors on the gut microbiota, these have now largely been replaced by culture-independent DNA-based approaches and most recently, high-throughput sequencing-based forms thereof. The aim of this review is to summarize recent research into the modulatory factors that impact on the acquisition and development of the infant gut microbiota, to outline the knowledge recently gained through the use of culture-independent techniques and, in particular, highlight advances in high-throughput sequencing and how these technologies have, and will continue to, fill gaps in our knowledge with respect to the human intestinal microbiota.

Efficacy of fidaxomicin versus vancomycin as therapy for Clostridium difficile infection in individuals taking concomitant antibiotics for other concurrent infections

Concomitant antibiotic (CA) use compromised initial response to Clostridium difficile infection therapy and durability of that response. Fidaxomicin was significantly more effective than vancomycin in achieving clinical cure in the presence of CAs and preventing recurrence regardless of CA use.

Background. Treatment guidelines recommend stopping all implicated antibiotics at the onset of Clostridium difficile infection (CDI), but many individuals have persistent or new infections necessitating the use of concomitant antibiotics (CAs). We used data from 2 phase 3 trials to study effects of CAs on response to fidaxomicin or vancomycin.

Methods. Subjects with CDI were treated for 10 days with fidaxomicin 200 mg every 12 hours or vancomycin 125 mg every 6 hours, assessed for resolution of symptoms, and followed up for an additional 4 weeks for evidence of recurrence. Rates of cure, recurrence, and global cure (cure without recurrence) were determined for subgroups of subjects defined by CA use and treatment group.

Results. CAs were prescribed for 27.5% of subjects during study participation. The use of CAs concurrent with CDI treatment was associated with a lower cure rate (84.4% vs 92.6%; P < .001) and an extended time to resolution of diarrhea (97 vs 54 hours; P < .001). CA use during the follow-up was associated with more recurrences (24.8% vs 17.7%; not significant), and CA administration at any time was associated with a lower global cure rate (65.8% vs 74.7%; P = .005). When subjects received CAs concurrent with CDI treatment, the cure rate was 90.0% for fidaxomicin and 79.4% for vancomycin (P = .04). In subjects receiving CAs during treatment and/or follow-up, treatment with fidaxomicin compared with vancomycin was associated with 12.3% fewer recurrences (16.9% vs 29.2%; P = .048).

Conclusions. Treatment with CAs compromised initial response to CDI therapy and durability of response. Fidaxomicin was significantly more effective than vancomycin in achieving clinical cure in the presence of CA therapy and in preventing recurrence regardless of CA use.

Clinical predictors of fulminant colitis in patients with Clostridium difficile infection

BACKGROUND/AIM

Clostridium difficile infection (CDI) can affect up to 8% of hospitalized patients. Twenty-five percent CDI patients may develop C. difficile associated diarrhea (CDAD) and 1-3% may progress to fulminant C. difficile colitis (FCDC). Once developed, FCDC has higher rates of complications and mortality.

PATIENTS AND METHODS

A 10-year retrospective review of FCDC patients who underwent colectomy was performed and compared with randomly selected age- and sex-matched non-fulminant CDAD patients at our institution. FCDC (n=18) and CDAD (n=49) groups were defined clinically, radiologically, and pathologically. Univariate analysis was performed using Chi-square and Student's t test followed by multivariate logistic regression to compute independent predictors.

RESULTS

FCDC patients were significantly older (77 ± 13 years), presented with triad of abdominal pain (89%), diarrhea (72%), and distention (39%); 28% had prior CDI and had greater hemodynamic instability. In contrast, CDAD patients were comparatively younger (65 ± 20 years), presented with only 1 or 2 of these 3 symptoms and only 5% had prior CDI. No significant difference was noted between the 2 groups in terms of comorbid conditions, use of antibiotics, or proton pump inhibitor. Leukocytosis was significantly higher in FCDC patients (18.6 ± 15.8/mm³ vs 10.7 ± 5.2/mm³; P=0.04) and further increased until the point of surgery. Use of antiperistaltic medications was higher in FCDC than CDAD group (56% vs 22%; P=0.01).

CONCLUSIONS

Our data suggest several clinical and laboratory features in CDI patients, which may be indicative of FCDC. These include old age (>70 years), prior CDI, clinical triad of increasing abdominal pain, distention and diarrhea, profound leukocytosis (>18,000/mm³), hemodynamic instability, and use of antiperistaltic medications.

Clostridium difficile infection in humans and piglets: a 'One Health' opportunity

Clostridium difficile causes infectious diarrhoea in humans and animals. It has been found in both diarrhoeal and non-diarrhoeal pigs, horses and cattle, suggesting a potential reservoir for human insection, and in 20-40 % of meat products in Canada and the USA, suggesting the possibility, albeit not proven, of food-borne transmission. Although it is not yet completely clear, it is likely that excessive antimicrobial exposure is driving the establishment of C. difficile in animals, in a manner analogous to human infection, rather than the organism just being normal flora of the animal gastrointestinal tract. PCR ribotype 078 is the most common ribotype of C. difficile found in pigs (83 % in one study in the USA) and cattle (up to 100 %) and this ribotype is now the third most common ribotype of C. difficile found in human infection in Europe. Human and pig strains of C. difficile are genetically identical in Europe confirming that a zoonosis exists. Rates of community-acquired C. difficile infection (CDI) are increasing world wide, a fact that sits well with the notion that animals are a reservoir for human infection. Thus, there are three problems that require resolution: a human health issue, an animal health issue and the factor common to both these problems, environmental contamination. To successfully deal with these recent changes in the epidemiology of CDI will require a 'one health' approach involving human health physicians, veterinarians and environmental scientists.

Increasing hospital costs for Clostridium difficile colitis: type of hospital matters

BACKGROUND

To assess differences in hospital costs for inpatients with Clostridium difficile (CD) colitis based on hospital size, rural or urban hospital setting, and hospital designation as a teaching institution.

METHODS

Data from the Pennsylvania Health Care Cost Containment Council (PHC4) were reviewed for 2005 to 2008. Cost-to-charge ratios were used to derive costs from hospital charges, adjusting costs for inflation. Propensity score-matched CD colitis and non-CD colitis cohorts were compared. Costs were modeled by generalized linear regression.

RESULTS

A total of 78,273 patients with CD colitis were identified. The average hospital cost per admission for patients with CD colitis was $22,094 compared to $10,865 for non-CD colitis patients. The 2005 to 2008 admission costs for CD colitis rose 9%, while the prevalence of CD colitis decreased by 13%. The costs for patients with CD colitis were consistently twice as much as those for non-CD colitis patients (P < .0001). Small facilities had the greatest costs overall (P < .0001). Urban and teaching facilities had greater costs than rural and nonteaching facilities (P < .0001), which corresponded to a greater proportion of patients with greater comorbidities (P < .0001). Among rural hospitals, the smallest facilities had the greatest costs (P < .0001), as did urban nonteaching hospitals (P < .0001). By contrast, costs did not differ among urban teaching hospitals of varying sizes (P = .35).

CONCLUSION

Costs for inpatient CD colitis in Pennsylvania have been increasing. Teaching and urban hospitals treat the group of patients with CD colitis with the greatest comorbidity, accounting for their greater cost of care. The cost of treating CD colitis is comparable among different sizes of teaching hospitals, which may reflect a more standardized approach toward treatment choices.

N-CDAD in Canada: results of the Canadian Nosocomial Infection Surveillance Program 1997 N-CDAD Prevalence Surveillance Project

BACKGROUND

A 1996 preproject survey among Canadian Hospital Epidemiology Committee (CHEC) sites revealed variations in the prevention, detection, management and surveillance of Clostridium difficile-associated diarrhea (CDAD). Facilities wanted to establish national rates of nosocomially acquired CDAD (N-CDAD) to understand the impact of control or prevention measures, and the burden of N-CDAD on health care resources. The CHEC, in collaboration with the Laboratory Centre for Disease Control (Health Canada) and under the Canadian Nosocomial Infection Surveillance Program, undertook a prevalence surveillance project among selected hospitals throughout Canada.

OBJECTIVE

To establish national prevalence rates of N-CDAD.

METHODS

For six weeks in 1997, selected CHEC sites tested all diarrheal stools from inpatients for either C difficile toxin or C difficile bacteria with evidence of toxin production. Questionnaires were completed for patients with positive stool assays who met the case definitions.

RESULTS

Nineteen health care facilities in eight provinces participated in the project. The overall prevalence of N-CDAD was 13.0% (95% CI 9.5% to 16.5%). The mean number of N-CDAD cases were 66.3 cases/100,000 patient days (95% CI 37.5 to 95.1) and 5.9 cases/1000 patient admissions (95% CI 3.4 to 8.4). N-CDAD was found most frequently in older patients and those who had been hospitalized for longer than two weeks in medical or surgical wards.

CONCLUSIONS

This national prevalence surveillance project, which established N-CDAD rates, is useful as 'benchmark' data for Canadian health care facilities, and in understanding the patterns and impact of N-CDAD.

Evaluation of doripenem utilization and susceptibilities at a large urban hospital

BACKGROUND

Bacterial resistance presents a constant challenge in the treatment of hospitalized patients, particularly with Gram-negative infections. Carbapenems have an important role in the treatment of resistant nosocomial organisms. Doripenem, a recently approved carbapenem, has shown efficacy in clinical trials, but there is little published data on utilization in a general patient population.

OBJECTIVE

The clinical utilization of doripenem in a general adult inpatient population was evaluated during a carbapenem formulary conversion.

SETTING

A 706-bed acute care tertiary hospital serving an urban community.

METHODS

After formulary conversion to doripenem, the first 100 patients to receive doripenem were included in the analysis. Baseline characteristics were recorded for each patient, along with indication for treatment, prescribing physician, dose and frequency of doripenem and duration of treatment. Patients were monitored for adverse reactions to doripenem. Bacterial culture results were recorded. For positive cultures, doripenem susceptibility was determined by Etest. Patients were followed until discontinuation of antibiotic therapy, discharge or death to determine treatment outcomes. Successful treatment was defined as clinical or microbiological cure, while patients with infection-related mortality or requiring subsequent antibiotics for the index infection were considered treatment failure.

MAIN OUTCOME MEASURES

Clinical utilization of doripenem, including indications and doses used.

RESULTS

Doripenem treatment was recorded in 102 patients. The most common indications for treatment were pneumonia and sepsis. The majority of doripenem orders were written by Infectious Disease or Pulmonology Services. Forty-nine patients were treated successfully with doripenem and six patients experienced treatment failure. The remainder of patients were not evaluable by predefined outcomes criteria. Adverse events were reported in eight patients and included acute renal failure, Clostridium difficile-associated diarrhea and seizures. Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were the most common organisms in culture results. Doripenem demonstrated in vitro activity against 81% of all organisms and susceptibility results had >90% correlation with meropenem and imipenem susceptibilities.

CONCLUSION

In our limited sample size, doripenem was safe and effective against various types of infections in a general inpatient population with similar bacterial susceptibilities to other cabapenems. Doripenem was utilized for appropriate indications, but doses were frequently outside the manufacturers labeling. Adverse events were uncommon, and no serious adverse events were directly associated with doripenem treatment.

Clostridium difficile Infection and Inflammatory Bowel Disease: A Review

The incidence of Clostridium difficile infection (CDI) has significantly increased in the last decade in the United States adding to the health care burden of the country. Patients with inflammatory bowel disease (IBD) have a higher prevalence of CDI and worse outcomes. In the past, the traditional risk factors for CDI were exposure to antibiotics and hospitalizations in elderly people. Today, it is not uncommon to diagnose CDI in a pregnant women or young adult who has no risk factors. C. difficile can be detected at the initial presentation of IBD, during a relapse or in asymptomatic carriers. It is important to keep a high index of suspicion for CDI in IBD patients and initiate prompt treatment to minimize complications. We summarize here the changing epidemiology, pathogenesis, risk factors, clinical features, and treatment of CDI in IBD.

Development and validation of a Clostridium difficile infection risk prediction model

OBJECTIVE

To develop and validate a risk prediction model that could identify patients at high risk for Clostridium difficile infection (CDI) before they develop disease.

DESIGN AND SETTING

Retrospective cohort study in a tertiary care medical center.

PATIENTS

Patients admitted to the hospital for at least 48 hours during the calendar year 2003.

METHODS

Data were collected electronically from the hospital's Medical Informatics database and analyzed with logistic regression to determine variables that best predicted patients' risk for development of CDI. Model discrimination and calibration were calculated. The model was bootstrapped 500 times to validate the predictive accuracy. A receiver operating characteristic curve was calculated to evaluate potential risk cutoffs.

RESULTS

A total of 35,350 admitted patients, including 329 with CDI, were studied. Variables in the risk prediction model were age, CDI pressure, times admitted to hospital in the previous 60 days, modified Acute Physiology Score, days of treatment with high-risk antibiotics, whether albumin level was low, admission to an intensive care unit, and receipt of laxatives, gastric acid suppressors, or antimotility drugs. The calibration and discrimination of the model were very good to excellent (C index, 0.88; Brier score, 0.009).

CONCLUSIONS

The CDI risk prediction model performed well. Further study is needed to determine whether it could be used in a clinical setting to prevent CDI-associated outcomes and reduce costs.

Clostridium difficile transcriptome analysis using pig ligated loop model reveals modulation of pathways not modulated in vitro

A pig ligated loop model was used to analyze the in vivo transcriptome response of Clostridium difficile. Bacterial RNA from the loops was retrieved at different times and was used for microarray analysis. Several virulence-associated genes and genes involved in sporulation cascade were differentially expressed (DE). In concordance with observed upregulation of toxin genes in microarray, enzyme-linked immunosorbent assay estimation of total toxin showed high amounts of toxin in the loops. Several genes that were absent in primary annotation of C. difficile 630 but annotated in a secondary annotation were found to be DE. Pathway comparison of DE genes in vitro and in vivo showed that when several pathways were expressed in all conditions, several of the C. difficile pathways were uniquely expressed only in vivo. The pathways observed to be modulated only in this study could be targets of new therapeutic agents against C. difficile infection.

Repeat stool testing to diagnose Clostridium difficile infection using enzyme immunoassay does not increase diagnostic yield

BACKGROUND & AIMS

Clostridium difficile infection (CDI) is a hospital-acquired infection with increasing incidence and severity. The most frequently used test to diagnose CDI is an enzyme immunoassay (EIA) for toxins A and B in stool samples. It is common to test 2 or more stool samples, based on the assumption that this detects CDI with greater sensitivity than analysis of 1 sample. We investigated whether repeat stool testing significantly improves the diagnostic yield for CDI.

METHODS

We performed a retrospective analysis of hospitalized patients who were tested for CDI using EIA. From year 2005 to 2008, 39,402 stool samples from 17,971 patients with 29,373 diarrhea episodes were tested. Transition probabilities were calculated based on results from repeated tests.

RESULTS

A total of 2692 diarrheal episodes (9.17%) were diagnosed with CDI. Based on results of 3 consecutive tests, 2675 (99.36%) were diagnosed with CDI. The first stool sample tested produced positive results for 90.7% of cases. When samples were tested consecutively, for the second and third time, an additional 6.6% and 2% patients had positive test results, respectively. If the first test result was negative, the probability of the second test result being positive was 2.7%. If the first 2 test results were negative, the probability of the third test result being positive was 2.3%.

CONCLUSIONS

In patients who had multiple stool samples tested for CDI by EIA, almost 91% were accurately diagnosed based on the results of a single stool sample alone. Subsequent testing yielded a positive result in only 8.6% of patients. We therefore recommend that repeat testing not be done on a routine basis because it does not significantly improve diagnostic yield.

Multidrug resistance in European Clostridium difficile clinical isolates

OBJECTIVES

Multidrug resistance and antibiotic resistance mechanisms were investigated in 316 Clostridium difficile clinical isolates collected during the first European surveillance on C. difficile in 2005.

METHODS

MICs of eight different antibiotics were determined using Etest. Reserpine- and carbonyl cyanide m-chlorophenylhydrazone-sensitive efflux was tested using the agar dilution method. Molecular analysis of the resistance mechanisms was performed using PCR assays, PCR mapping and sequencing.

RESULTS

One hundred and forty-eight C. difficile strains were resistant to at least one antibiotic and 82 (55%) were multidrug resistant. In particular, 48% of these isolates were resistant to erythromycin, clindamycin, moxifloxacin and rifampicin. New genetic elements or determinants conferring resistance to erythromycin/clindamycin or tetracycline were identified. Even if most multiresistant strains carried an erm(B) gene, quite a few were erm(B) negative. In-depth analysis of the underlying mechanism in these isolates was carried out, including analysis of 23S rDNA and the ribosomal proteins L4 and L22. Interestingly, resistance to rifampicin was observed in multidrug-resistant strains in association with resistance to fluoroquinolones. Mutations in the rpo(B) and gyrA genes were identified as the cause of resistance to these antibiotics, respectively.

CONCLUSIONS

Characterization of multidrug-resistant C. difficile clinical isolates shows that antibiotic resistance is changing, involving new determinants and mechanisms and providing this pathogen with potential advantages over the co-resident gut flora. The present paper provides, for the first time, a comprehensive picture of the different characteristics of multidrug-resistant C. difficile strains in Europe in 2005 and represents an important source of data for future comparative European studies.

Incidence of and risk factors for community-associated Clostridium difficile infection: a nested case-control study

BACKGROUND

Clostridium difficile is the most common cause of nosocomial infectious diarrhea in the United States. However, recent reports have documented that C. difficile infections (CDIs) are occurring among patients without traditional risk factors. The purpose of this study was to examine the epidemiology of CA-CDI, by estimating the incidence of CA-CDI and HA-CDI, identifying patient-related risk factors for CA-CDI, and describing adverse health outcomes of CA-CDI.

METHODS

We conducted a population-based, retrospective, nested, case-control study within the University of Iowa Wellmark Data Repository from January 2004 to December 2007. We identified persons with CDI, determined whether infection was community-associated (CA) or hospital-acquired (HA), and calculated incidence rates. We collected demographic, clinical, and pharmacologic information for CA-CDI cases and controls (i.e., persons without CDI). We used conditional logistic regression to estimate the odds ratios (ORs) for potential risk factors for CA-CDI.

RESULTS

The incidence rates for CA-CDI and HA-CDI were 11.16 and 12.1 cases per 100,000 person-years, respectively. CA-CDI cases were more likely than controls to receive antimicrobials (adjusted OR, 6.09 [95% CI 4.59-8.08]) and gastric acid suppressants (adjusted OR, 2.30 [95% CI 1.56-3.39]) in the 180 days before diagnosis. Controlling for other covariates, increased risk for CA-CDI was associated with use of beta-lactam/beta-lactamase inhibitors, cephalosporins, clindamycin, fluoroquinolones, macrolides, and penicillins. However, 27% of CA-CDI cases did not receive antimicrobials in the 180 days before their diagnoses, and 17% did not have any traditional risk factors for CDI.

CONCLUSIONS

Our study documented that the epidemiology of CDI is changing, with CA-CDI occurring in populations not traditionally considered "high-risk" for the disease. Clinicians should consider this diagnosis and obtain appropriate diagnostic testing for outpatients with persistent or severe diarrhea who have even remote antimicrobial exposure.

Incidence of and risk factors for community-associated Clostridium difficile infection: a nested case-control study

Background

Clostridium difficile is the most common cause of nosocomial infectious diarrhea in the United States. However, recent reports have documented that C. difficile infections (CDIs) are occurring among patients without traditional risk factors. The purpose of this study was to examine the epidemiology of CA-CDI, by estimating the incidence of CA-CDI and HA-CDI, identifying patient-related risk factors for CA-CDI, and describing adverse health outcomes of CA-CDI.

Methods

We conducted a population-based, retrospective, nested, case-control study within the University of Iowa Wellmark Data Repository from January 2004 to December 2007. We identified persons with CDI, determined whether infection was community-associated (CA) or hospital-acquired (HA), and calculated incidence rates. We collected demographic, clinical, and pharmacologic information for CA-CDI cases and controls (i.e., persons without CDI). We used conditional logistic regression to estimate the odds ratios (ORs) for potential risk factors for CA-CDI.

Results

The incidence rates for CA-CDI and HA-CDI were 11.16 and 12.1 cases per 100,000 person-years, respectively. CA-CDI cases were more likely than controls to receive antimicrobials (adjusted OR, 6.09 [95% CI 4.59-8.08]) and gastric acid suppressants (adjusted OR, 2.30 [95% CI 1.56-3.39]) in the 180 days before diagnosis. Controlling for other covariates, increased risk for CA-CDI was associated with use of beta-lactam/beta-lactamase inhibitors, cephalosporins, clindamycin, fluoroquinolones, macrolides, and penicillins. However, 27% of CA-CDI cases did not receive antimicrobials in the 180 days before their diagnoses, and 17% did not have any traditional risk factors for CDI.

Conclusions

Our study documented that the epidemiology of CDI is changing, with CA-CDI occurring in populations not traditionally considered "high-risk" for the disease. Clinicians should consider this diagnosis and obtain appropriate diagnostic testing for outpatients with persistent or severe diarrhea who have even remote antimicrobial exposure.

Efficacy of decontaminants and disinfectants against Clostridium difficile

Clostridium difficile is a common nosocomial pathogen transmitted mainly via its spores. These spores can remain viable on contaminated surfaces for several months and are resistant to most commonly used cleaning agents. Thus, effective decontamination of the environment is essential in preventing the transmission of C. difficile in health-care establishments. However, this emphasis on decontamination must also be extended to laboratories due to risk of exposure of staff to potentially virulent strains. Though few cases of laboratory-acquired infection have been reported, the threat of infection by C. difficile in the laboratory is real. Our aim was to test the efficacy of four disinfectants, Actichlor, MicroSol 3+, TriGene Advance and Virkon, and one laboratory decontaminant, Decon 90, against vegetative cells and spores of C. difficile. Five strains were selected for the study: the three most commonly encountered epidemic strains in Scotland, PCR ribotypes 106, 001 and 027, and control strains 630 and VPI 10463. MICs were determined by agar dilution and broth microdilution. All the agents tested inhibited the growth of vegetative cells of the selected strains at concentrations below the recommended working concentrations. Additionally, their effect on spores was determined by exposing the spores of these strains to different concentrations of the agents for different periods of time. For some of the agents, an exposure of 10 min was required for sporicidal activity. Further, only Actichlor was able to bring about a 3 log(10) reduction in spore numbers under clean and dirty conditions. It was also the only agent that decontaminated different hard, non-porous surfaces artificially contaminated with C. difficile spores. However, this too required an exposure time of more than 2 min and up to 10 min. In conclusion, only the chlorine-releasing agent Actichlor was found to be suitable for the elimination of C. difficile spores from the environment, making it the agent of choice for the decontamination of laboratory surfaces.

Preventing Clostridium difficile infections: an executive summary of the Association for Professionals in Infection Control and Epidemiology's elimination guide

This article is an executive summary of the Association for Professionals in Infection Control and Epidemiology's Clostridium difficile infection elimination guide. Infection preventionists are encouraged to obtain the original, full-length elimination guide for more thorough coverage of C difficile infection prevention.

Alternative therapies for Clostridium difficile infections

Clostridium difficile infection is a serious condition responsible for significant morbidity and mortality, especially in patients being treated with antimicrobials. Increasing frequency of the infection and hypervirulent C. difficile strains have resulted in more severe disease as well as therapeutic failures with traditional treatment (metronidazole and vancomycin). To review the studies assessing nontraditional therapies for the prevention and treatment of primary or recurrent C. difficile infection, we conducted a literature search of the PubMed-MEDLINE databases (1984-2010). Of the 98 studies identified, 21 met our inclusion criteria. Five clinical trials and one retrospective medical record review evaluated probiotic or prebiotic formulations for the prevention of C. difficile infection. Only one of these studies, which included Lactobacillus casei and L. bulgaricus in the probiotic formulation, showed efficacy. Ten clinical trials evaluated treatment of an initial episode of C. difficile infection (primary treatment) with the anti-microbials fidaxomicin, fusidic acid, rifampin, teicoplanin, and nitazoxanide, as well as the toxin-binding polymer, tolevamer. Only nitazoxanide and teicoplanin demonstrated noninferiority when compared with vancomycin or metronidazole. Four prospective studies and one retrospective study evaluated treatment of relapsing C. difficile infection. Prebiotic formulations for the prevention and treatment of recurrent C. difficile infection have not proved to be clinically warranted. Nitazoxanide, teicoplanin, and fidaxomicin may be considered as alternatives to traditional treatment; however, clinical experience is limited with these agents for this indication. Bacteriotherapy with fecal instillation has demonstrated high clinical cure rates in case studies and in a retrospective study; however, to our knowledge, randomized clinical trials are lacking for this therapeutic approach. As C. difficile infection rates continue to increase and hypervirulent strains continue to emerge, it is important for future clinical studies to assess alternative therapies.

Clostridium difficile enteritis: a review and pooled analysis of the cases

INTRODUCTION

Clostridium difficile is the most common cause of healthcare-associated infection diarrhea and usually restricted to infection of the colon. However, small bowel involvement of C. difficile infection has been reported. We performed a literature review and pooled analysis of the reported cases of C. difficile enteritis

METHOD

A Pubmed literature database search and pooled analysis of the reported cases of C. difficile enteritis.

RESULTS

56 cases of C. difficile enteritis have been reported from 1980 to 2010; 48 cases were published since 2001. Median age was 55 years. 27 patients (48.2%) were female. 29 patients (51.8%) had inflammatory bowel disease (IBD) - Crohn's disease or ulcerative colitis and 20 patients (35.7%) had predisposing medical condition(s) that might lead to an immunoincompetent state. 33 patients (58.9%) had colectomy with ileostomy and 13 patients (23.2%) had other small and/or large bowel surgery. Thirty four patients (60.7%) received ICU management and 18 patients (32.1%) died. We categorized the patients into two groups, 38 survivors (67.9%) 18 non-survivors (32.1%). Significantly older age was noted in non-survivors. Median age was 48 years and 66 years, respectively for survivors and non-survivors, P < 0.001. There were more patients with predisposing medical condition(s) among non-survivors, (13/18, 72.2%) than among survivors (7/38, 18.4%), P < 0.001.

CONCLUSIONS

C. difficile enteritis is still rare, however it seems to be increasingly reported in recent years. Surgically altered intestinal anatomies, advanced age, predisposing medical condition(s) that might lead to immunoincompetence appear to be at risk for developing C. difficile enteritis. Recognition of C. difficile infection not only in the colon but also in the small bowel may lead to improved outcomes.

Fidaxomicin versus vancomycin for Clostridium difficile infection

BACKGROUND

Clostridium difficile infection is a serious diarrheal illness associated with substantial morbidity and mortality. Patients generally have a response to oral vancomycin or metronidazole; however, the rate of recurrence is high. This phase 3 clinical trial compared the efficacy and safety of fidaxomicin with those of vancomycin in treating C. difficile infection.

METHODS

Adults with acute symptoms of C. difficile infection and a positive result on a stool toxin test were eligible for study entry. We randomly assigned patients to receive fidaxomicin (200 mg twice daily) or vancomycin (125 mg four times daily) orally for 10 days. The primary end point was clinical cure (resolution of symptoms and no need for further therapy for C. difficile infection as of the second day after the end of the course of therapy). The secondary end points were recurrence of C. difficile infection (diarrhea and a positive result on a stool toxin test within 4 weeks after treatment) and global cure (i.e., cure with no recurrence).

RESULTS

A total of 629 patients were enrolled, of whom 548 (87.1%) could be evaluated for the per-protocol analysis. The rates of clinical cure with fidaxomicin were noninferior to those with vancomycin in both the modified intention-to-treat analysis (88.2% with fidaxomicin and 85.8% with vancomycin) and the per-protocol analysis (92.1% and 89.8%, respectively). Significantly fewer patients in the fidaxomicin group than in the vancomycin group had a recurrence of the infection, in both the modified intention-to-treat analysis (15.4% vs. 25.3%, P=0.005) and the per-protocol analysis (13.3% vs. 24.0%, P=0.004). The lower rate of recurrence was seen in patients with non–North American Pulsed Field type 1 strains. The adverse-event profile was similar for the two therapies.

CONCLUSIONS

The rates of clinical cure after treatment with fidaxomicin were noninferior to those after treatment with vancomycin. Fidaxomicin was associated with a significantly lower rate of recurrence of C. difficile infection associated with non–North American Pulsed Field type 1 strains. (Funded by Optimer Pharmaceuticals; ClinicalTrials.gov number, NCT00314951.)