NAP1 strain type predicts outcomes from Clostridium difficile infection

Establishing an Antimicrobial Stewardship Collaborative Across a Large, Diverse Health Care System

Alarming trends in antibiotic resistance sparked a National Action Plan endorsing antimicrobial stewardship programs (ASPs) in health care facilities. Atrium Health consists of 28 acute care facilities with varying levels of ASP maturity. The organization sought to establish an ASP collaborative across a diverse network by uniting local resources with a central advisory team.

METHODS

In fall 2015 each facility chose a pharmacist, a physician, and an administrative ASP champion. Broad-spectrum antibiotic use was tracked monthly using days of therapy (DOT) per 1,000 patient-days as a standard metric. A gap analysis survey of Centers for Disease Control and Prevention (CDC) core elements for ASPs was conducted to stratify facilities into one of three tiers, with Tier 1 having the most comprehensive ASP. Baseline antibiotic usage data were collected, and DOT reduction goals were set for each facility. Site visits were conducted in winter 2016, and a post-visit summary outlining major goals was provided. Pharmacists held monthly facility meetings to assess progress and a bimonthly virtual meeting for sharing best practices networkwide. In addition, curriculum for an ASP symposium was developed based on identified educational needs.

RESULTS

Almost all hospitals (25/28) fully implemented the CDC core elements for ASPs within the first year of establishing the systemwide collaborative. Most facilities (78.6%) achieved their DOT reduction goal ranging from 1%-2.5% to 5%-10%.

CONCLUSION

Despite many challenges, building a unified ASP collaborative across a diverse system enabled many hospitals to adopt best practices and improve antimicrobial use.

Clostridium difficile infection: Description of NAP1/027 and non NAP1/027 strains in a high complexity center in Cali, Colombia, 2012-2015

Introduction: Clostridium difficile causes nosocomial infections leading to high morbidity and mortality. The NAP1/027 strain is associated with a higher toxin production and disease severity, which increases the load of the disease. Objective: To describe the epidemiology of the infections associated with C. difficile and the characteristics related to the NAP1/027 strain. Materials and methods: This was an observational study based on the revision of clinical registries of patients with fecal samples that were positive for C. difficile identified by the Xpert test™ between 2012 and 2015 in a high complexity institution. The severity of the disease was evaluated by means of the ATLAS score. Results: We included 42 infected cases, 9 of which were positive for the NAP1/027strain. The use of antibiotics previous to the infection for more than seven days was more frequent in patients with negative results for NAP1/027. The duration of diarrhea in half of the patients was longer than five days and there were no differences according to the type of strain (p>0.05). Positive cases for the NAP1/027 strain were characterized by presenting fetid and bloody stools. The severity of the infection was similar between the groups. Conclusions: In Colombia, the NAP1/027 strain circulates without significant clinical differences, which could be due to the limited number of patients. Nevertheless, the existence of NAP1/027 should alert physicians and health institutions because of its high association with severity and mortality.

Multilocus Variable-Number Tandem-Repeat Analysis of Clostridioides difficile Clusters in Ribotype 027 Isolates and Lack of Association with Clinical Outcomes

The epidemiology of Clostridioides difficile infection (CDI) has drastically changed since the emergence of the epidemic strain BI/NAP1/027, also known as ribotype 027 (R027). However, the relationship between the infecting C. difficile strain and clinical outcomes is still debated. We hypothesized that certain subpopulations of R027 isolates could be associated with unfavorable outcomes. We applied high-resolution multilocus variable-number tandem-repeat analysis (MLVA) to characterize C. difficile R027 isolates collected from confirmed CDI patients recruited across 10 Canadian hospitals from 2005 to 2008. PCR ribotyping was performed first to select R027 isolates that were then analyzed by MLVA (n = 450). Complicated CDI (cCDI) was defined by the occurrence of any of admission to an intensive care unit, colonic perforation, toxic megacolon, colectomy, and if CDI was the cause or contributed to death within 30 days after enrollment. Three major MLVA clusters were identified, MC-1, MC-3, and MC-10. MC-1 and MC-3 were exclusive to Quebec centers, while MC-10 was found only in Ontario. Fewer cases infected with MC-1 developed cCDI (4%) than those infected with MC-3 and MC-10 (15% and 16%, respectively), but a statistically significant difference was not reached. Our data did not identify a clear association between subpopulations of R027 and different clinical outcomes; however, the data confirmed the utility of MLVA's higher discrimination potential to better characterize CDI populations in an epidemiological analysis. For a patient with CDI, the progression toward an unfavorable outcome is a complex process that probably includes several interrelated strain and host characteristics.

To Lump or To Split: Does Strain Lineage for Clostridioides difficile Matter?

Since 2001, numerous descriptive ecological studies of Clostridioides difficile infections (CDI) have identified a single lineage (BI/NAP1/027) associated with the epidemics of CDI, increased severity of CDI, and increased likelihood of incident CDI to become recurrent. Establishing causality between the clinical severity and outcomes for CDI and the lineages of the infecting strains, however, has proved elusive, with many conflicting results in previous observational studies. In this issue of the Journal of Clinical Microbiology, J. R. Garneau, C. N. Abou Chakra, L.-C. Fortier, A.-C. Labbé, et al. (J Clin Microbiol 57:e01724-18, 2019, https://doi.org/10.1128/JCM.01724-18) performed multilocus variable-number tandem-repeat analysis (MLVA) on 450 isolates from epidemic strain CDI arising in 10 Canadian centers during a previously well-described epidemic to assess the hypothesis that subpopulations of this lineage are associated with adverse clinical outcomes. The authors' key finding, however, was that MLVA genotyping grouped infections closely with associated hospital centers; CDI severity was not associated with any particular sublineage by MLVA. While the study does not support any causal inferences about strain-specific virulence of CDI, it does highlight the power of MLVA, a genotyping tool that remains valuable in tracking the geospatial transmission dynamics of CDI.

Extended-pulsed fidaxomicin versus vancomycin for Clostridium difficile infection: EXTEND study subgroup analyses

Poor outcomes following Clostridium difficile infection (CDI) have been associated with advanced age, presence of cancer and C. difficile PCR-ribotype 027. The impact of baseline risk factors on clinical outcomes was evaluated using data from the EXTEND study, in which rate of sustained clinical cure (SCC) in the overall population was significantly higher with an extended-pulsed fidaxomicin (EPFX) regimen than with vancomycin. Patients aged ≥ 60 years received EPFX (fidaxomicin 200 mg twice daily, days 1–5; once daily on alternate days, days 7–25) or vancomycin (125 mg four times daily, days 1–10). We analysed outcomes by advanced age, cancer diagnosis, CDI severity, prior CDI occurrence and infection with PCR-ribotype 027. The primary endpoint was SCC 30 days after end of treatment (EOT; clinical response at test-of-cure with no subsequent recurrence). SCC rates 30 days after EOT did not differ significantly between EPFX (124/177, 70.1%) and vancomycin (106/179, 59.2%) regardless of age, cancer diagnosis, CDI severity and prior CDI. In patients with PCR-ribotype 027, SCC rate 30 days after EOT was significantly higher with EPFX (20/25, 80%) than with vancomycin (9/22, 40.9%) (treatment difference, 39.1%; 95% CI, 13.2–64.9; P = 0.006). Subgroup analyses from the EXTEND study suggest that EPFX is efficacious as a potential treatment for CDI regardless of age, cancer diagnosis, infection with PCR-ribotype 027, CDI severity or prior CDI. ClinicalTrials.gov identifier: NCT02254967.

PCR based detection of tcdCΔ117 in Clostridium difficile infection identifies patients at risk for recurrence - A hospital-based prospective observational study

OBJECTIVES

Increasing incidence and severity of Clostridium difficile infection (CDI) in the last decades has been attributed to the emergence of hypervirulent C. difficile strain PCR-ribotype 027 (RT027). Commercial multiplex real-time PCR tests allow the presumptive identification of RT027 by detecting a single-base deletion at nt117 in the tcdC gene (tcdCΔ117). The clinical usefulness of the detection of tcdCΔ117 is unclear. Therefore, we evaluated test performance and clinical association of the detection of tcdCΔ117 in patients with CDI in a prospective observational study conducted in a tertiary care hospital in Germany.

METHODS

From June to October 2015, stool from all patients with suspected CDI was tested for C. difficile according to ESCMID guidelines. C. difficile was cultured from positive samples and ribotyping was performed. Clinical data were collected prospectively from all C. difficile positive patients.

RESULTS

From 1121 tested stool samples 107 patients with CDI were included in the study. TcdCΔ117 was detected in 18 (16.8%) of these patients. Multivariable logistic regression analysis revealed an independent association of detection of tcdCΔ117 with a further episode of CDI (OR 14.6; 95% CI 3.6-58.3; p < 0.001) and death within 30 days of the positive test (OR 5.1; 95% CI 1.0-25.7; p = 0.046). As follow up data are limited, it remains unclear, whether the further episode of CDI was due to tcdCΔ117 (recurrence) or another type.

CONCLUSION

In our setting, PCR-based detection of tcdCΔ117 identified patients at risk for recurrent CDI and increased mortality and thus may guide therapeutic choices in CDI patients at the time of diagnosis.

The Hypervirulent Strain of Clostridium Difficile: NAP1/B1/027 - A Brief Overview

Clostridium difficile is a gram-positive bacterium notorious for causing epidemic diarrhea globally with a significant health burden. The pathogen is clinically challenging with increasing antibiotic resistance and recurrence rate. We provide here an in-depth review of one particular strain/ribotype 027, commonly known as NAP1/B1/027 or North American pulsed-field gel electrophoresis type 1, restriction endonuclease analysis type B1, polymerase chain reaction ribotype 027, which has shown a much higher recurrence rate than other strains.

Assessing the social cost and benefits of a national requirement establishing antibiotic stewardship programs to prevent Clostridioides difficile infection in US hospitals

Backgound

Economic evaluations of interventions to prevent healthcare-associated infections in the United States rarely take the societal perspective and thus ignore the potential benefits of morbidity and mortality risk reductions. Using new Department of Health and Human Services guidelines for regulatory impact analysis, we developed a cost-benefit analyses of a national multifaceted, in-hospital Clostridioides difficile infection prevention program (including staffing an antibiotic stewardship program) that incorporated value of statistical life estimates to obtain economic values associated with morbidity and mortality risk reductions.

Methods

We used a net present value model to assess costs and benefits associated with antibiotic stewardship programs. Model inputs included treatment costs, intervention costs, healthcare-associated Clostridioides difficile infection cases, attributable deaths, and the value of statistical life which was used to estimate the economic value of morbidity and mortality risk reductions.

Results

From 2015 to 2020, total net benefits of the intervention to the healthcare system range from $300 million to $7.6 billion when values for morbidity and mortality risk reductions are ignored. Including these values, the net social benefits of the intervention range from $21 billion to $624 billion with the annualized net benefit of $25.5 billion under our most likely outcome scenario.

Conclusions

Incorporating the economic value of morbidity and mortality risk reductions in economic evaluations of healthcare-associated infections will significantly increase the benefits resulting from prevention.

Hypoalbuminemia as predictor of recurrence of Clostridium difficile infection

Background

Novel drugs for Clostridium difficile (C. difficile) infections have been proven to reduce recurrent infections. Because of their high financial costs, identification of patients at high risk for recurrence is essential to provide optimal treatment. The ATLAS score’s ability to predict 90-day recurrence, disease complications and 1‑year all-cause mortality was evaluated.

Methods

144 consecutive symptomatic patients with positive stool test for C. difficile were enrolled. The ATLAS score (consisting of the variables age, temperature, leukocyte count, albumin, systemic antibiotics, serum creatinine) was calculated and patients were stratified into 4 subgroups according to their scores. A Cox regression model was used to estimate the extent to which ATLAS was associated with 90-day recurrence. Furthermore, the score was correlated with disease complications and one-year all-cause mortality.

Results

ATLAS was unable to predict 90-day recurrence (p = 0.064, HR 1.134 [0.993;1.295]), but performed well for disease complications (D = 0.382, p < 0.001, HR 1.547 [1.266;1.889]) and mortality (p < 0.001, HR 1.374 [1.194;1.583]). Serum albumin was the only parameter able to predict 90-day recurrence (p = 0.016, HR 0.958 [0.926;0.992]) and was also a predictor of disease complications (p < 0.001, HR 0.865[0.809;0.924]) and one-year all-cause mortality (p < 0.001, HR 0.923 [0.896;0.950]). A threshold of 33.1g/L (sensitivity = 56%, specificity = 80%, AUC 0.683) and 29.2g/L (sensitivity = 75%, specificity = 70%, AUC 0.763) of serum albumin could be identified to be predictive for 90-day recurrence and one-year all-cause mortality, respectively.

Conclusions

Serum albumin and ATLAS are predictors of disease complications and mortality, while only serum albumin is significantly associated with 90-day disease recurrence.

Bezlotoxumab Is Associated With a Reduction in Cumulative Inpatient-Days: Analysis of the Hospitalization Data From the MODIFY I and II Clinical Trials

Background

Patients with recurrent Clostridium difficile infection (rCDI) are more likely to have a hospital readmission and spend increased time in inpatient settings compared with patients with primary CDI. MODIFY I and II demonstrated that bezlotoxumab significantly reduced rCDI vs placebo. A post hoc within-trial analysis assessed whether bezlotoxumab was associated with a reduction in cumulative inpatient-days.

Methods

Data were pooled from the MODIFY trials to estimate the cumulative hospitalized days summed over the 84-day follow-up period. We adjusted inpatient use data from pooled MODIFY I and II for survival and censoring to estimate 84-day cumulative inpatient-days, overall and for subgroups. Treatment effects were obtained using recycled predictions based on trial protocol and rCDI risk, and 95% confidence intervals were obtained using 1000 bootstrap replicates.

Results

Mean cumulative inpatient-days were greater in the placebo arm (14.1 days) vs the bezlotoxumab arm (12.1 days) in the overall population. The mean difference between treatment groups was 2.1 days (95% confidence interval, –0.4 to –3.7). This was consistent in participants with risk factors for rCDI: age ≥65 years, compromised immunity, severe CDI, prior CDI, and ribotype 027/078/244 infection. As the number of risk factors increased, bezlotoxumab resulted in greater reductions in the number of inpatient-days compared with placebo (difference: –1.2 days, –2.3 days, –2.5 days, and –3.0 days for 0, 1, 2, and ≥3 risk factors, respectively).

Conclusions

Bezlotoxumab was associated with a reduction in cumulative inpatient-days, suggesting that treatment with bezlotoxumab may substantially reduce rCDI-associated health care resource use.

Trial registrations. MODIFY I (MK-3415A-001, NCT01241552) and II (MK-3415A-002, NCT01513239)

Oral vancomycin versus metronidazole for the treatment of Clostridioides difficile infection: Meta-analysis of randomized controlled trials

At present, vancomycin (VCM) and metronidazole (MNZ) are used for the first-line standard treatment of Clostridioides difficile infection (CDI). However, their differential use has not been sufficiently investigated. In this study, a meta-analysis on differences in the efficacy for CDI between VCM and MNZ was performed. Reports of randomized controlled studies using VCM or MNZ to treat CDI were surveyed. Meta-analysis was performed using the Mantel-Haenszel method and random-effects model, and the risk ratio and 95% confidence interval were calculated. Excluding overlapping reports, 1043 reports were extracted and 5 randomized controlled studies were extracted. There was no difference in therapeutic effects for CDI between VCM and MNZ (RR = 1.08, 95% CI (0.99-1.17), p = 0.09, I² = 37%). On subgroup analysis by the severity, there was no difference in the clinical effects for CDI between VCM and MNZ in non-severe cases (risk ratio: 1.09, 95% confidence interval: 1.00-1.19, p = 0.06), but the clinical effects of VCM were significantly higher than those of MNZ in severe cases (risk ratio: 1.19, 95% confidence interval: 1.02-1.39, p = 0.03). No significant difference was noted in the recurrence rate, incidence of adverse event, time to exhibit therapeutic effects, or judgment of the bacteriological effects. As the therapeutic effects of VCM were superior in severe CDI cases, VCM should be considered first in severe cases.

Risk Factors, Incidence, and Morbidity Associated With Obstetric Clostridium difficile Infection

OBJECTIVE

To evaluate the risk factors, incidence, and morbidity associated with the diagnosis of obstetric Clostridium difficile infection.

METHODS

We performed a retrospective cohort study on women admitted for delivery using the Healthcare Cost and Utilization Project Nationwide Inpatient Sample from the United States. The delivery admission records of pregnant women were reviewed between 1999 and 2013. After adjusting for demographic and clinical characteristics, we assessed risk factors for the diagnosis of C difficile infection using unconditional logistic regression.

RESULTS

Of the total 13,881,592 births in our cohort, we identified 2,757 (0.02%) admissions for delivery complicated by a diagnosis of C difficile infection. During the study period, the rate of C difficile infection diagnoses among women hospitalized for delivery doubled from 15 (95% CI 11.87-16.96) to 30 (24.42-31.78) per 100,000 deliveries per year (P<.001). Risk factors associated with the diagnosis of C difficile infection included age older than 35 years, multiple gestations, smoking, Crohn's disease, ulcerative colitis, long-term antibiotic use, pneumonia, pyelonephritis as well as cesarean or perineal wound infection. The diagnosis of C difficile infection in pregnancy was associated with a significant increase in maternal death (8.0/1,000 vs 0.1/1,000, adjusted odds ratio [OR] 56.8, 95% CI 35.8-90.1). Furthermore, there was an increase in sepsis (46.4/1,000 vs 0.6/1,000, adjusted OR 59.1, 95% CI 48.8-71.6), paralytic ileus (58.0/1,000 vs 1.5/1,000, adjusted OR 33.1, 95% CI 27.5-39.8), venous thromboembolism (38.4/1,000 vs 3.1/1,000, adjusted OR 8.1, 95% CI 6.5-10.2), and hospital stays greater than 2 weeks (173.0/1,000 vs 6.5,1,000, adjusted OR 24.3, 95% CI 21.6-27.4) among pregnant women with C difficile infection.

CONCLUSION

The diagnosis of C difficile infections in pregnancy has increased over the past 15 years and this diagnosis is associated with significant maternal morbidity and mortality.

Utility of multiplex polymerase chain reaction (PCR) in diarrhea-An Indian perspective

BACKGROUND

Infective diarrhea causes morbidity worldwide. Polymerase chain reaction (PCR)-based pathogen diagnostics of diarrheal stool specimens are shown to be highly sensitive and rapid as opposed to conventional diagnostics.

METHODS

We analyzed the performance of FilmArray gastrointestinal (GI) panel, one such multiplex PCR test, on stool specimens in patients presenting with diarrhea to our hospital from March 2016 to September 2017 and compared the results with conventional diagnostic tests.

RESULTS

A total of 106 patients were included. The panel detected at least one target in 54 out of 106 patients (50.9%) with results available on the same day. Multiple targets were detected in 26 out of 54 patients who tested positive (48.1%). Bacteria as an isolated etiology for diarrhea was present in 34 patients (62.9%), viruses (16.7%, nine patients), parasites (7.4%, four patients), and multiple pathogens in seven patients (12.9%). Enteroaggregative Escherichia coli (EAEC) was the commonest pathogen detected (in 23, 24% patients). Conventional diagnostic investigations, undertaken in 68/106 (64.1%) patients were positive in 12 (17.65%) as compared to 54/106 (50.9%) (p < 0.0001). Conventional  investigations detected a pathogen not included in the study panel in 11 of 52 patients (21.1%).

CONCLUSION

FilmArray multiplex PCR panel detects a wide array of GI pathogens including viruses and co-infections at a shorter time with more sensitivity compared to conventional diagnostics. Henceforth, it may facilitate treatment decisions, isolation policy, and antimicrobial stewardship in patients with diarrhea requiring hospitalization.

Epidemiological and genomic characterization of community-acquired Clostridium difficile infections

BACKGROUND

Clostridium difficile infection (CDI) is a major cause of morbidity and mortality in North America and Europe. The aim of this study was to identify epidemiologically-confirmed cases of community-acquired (CA)-CDI in a large North American urban center and analyze isolates using multiple genetic and phenotypic methods.

METHODS

Seventy-eight patients testing positive for C. difficile from outpatient clinics were further investigated by telephone questionnaire. CA-CDI isolates were characterized by antibiotic susceptibility, pulsed-field gel electrophoresis and whole genome sequencing. CA-CDI was defined as testing positive greater than 12 weeks following discharge or no previous hospital admission in conjunction with positive toxin stool testing.

RESULTS

51.3% (40/78) of the patients in this study were found to have bona fide CA-CDI. The majority of patients were female (71.8% vs. 28.2%) with 50-59 years of age being most common (21.8%). Common co-morbidities included ulcerative colitis (1/40; 2.5%), Crohn's disease (3/40; 7.5%), celiac disease (2/40; 5.0%) and irritable bowel syndrome (8/40; 20.0%). However, of 40 patients with CA-CDI, 9 (29.0%) had been hospitalized between 3 and 6 months prior and 31 (77.5%) between 6 and 12 months prior. The hypervirulent North American Pulostype (NAP) 1-like (9/40; 22.5%) strain was the most commonly identified pulsotype. Whole genome sequencing of CA-CDI isolates confirmed that NAP 1-like pulsotypes are commonplace in CA-CDI. From a therapeutic perspective, there was universal susceptibility to metronidazole and vancomycin.

CONCLUSIONS

All CA-CDI cases had some history of hospitalization if the definition were modified to health care facility exposure in the last 12 months and is supported by the genomic analysis. This raises the possibility that even CA-CDI may have nosocomial origins.

Primary Prevention of Clostridium difficile-Associated Diarrhea: Current Controversies and Future Tools

PURPOSE OF REVIEW

Clostridium difficile infection (CDI) is a major cause of morbidity and mortality in hospitalized patients and rates in most places have not decreased significantly despite broad efforts by both hospitals and public health entities. This review aims to provide readers with a better understanding of the limitations of current prevention strategies. We also review potential future tools that may be available for the primary prevention of CDI in the next decade.

RECENT FINDINGS

Research over the last decade has expanded our appreciation of the role of asymptomatic shedding in the healthcare setting and in the community. This review demonstrates that poor quality data underlies even well-established guidance from national authorities on basic topics such as contact precautions, avoidance of alcohol-based hand hygiene products, CDI testing, supplemental cleaning modalities, and the use of bleach solutions. Additionally, we review research on novel preventative interventions such as identification of asymptomatic carriers, supplemental environmental cleaning technologies, vaccines, and the manipulation of the intestinal microbiome. While there is preliminary data that supports further research in all of these areas, the research is not yet robust enough on which to base local or national policy recommendations, though late-phase human clinical trials of CDI vaccine trials are ongoing. Over the last decade, researchers have begun to reassess the traditional infection prevention model for CDI. Data suggesting a greater role for asymptomatic shedders has increased our understanding of current vertical prevention techniques and is forcing researchers to look more at new processes and technologies to decrease disease incidence.

Risk factors for recurrence in patients with Clostridium difficile infection due to 027 and non-027 ribotypes

OBJECTIVES

Our objective was to evaluate factors associated with recurrence in patients with 027+ and 027- Clostridium difficile infection (CDI).

METHODS

Patients with CDI observed between January and December 2014 in six hospitals were consecutively included in the study. The 027 ribotype was deduced by the presence of tcdB, tcdB, cdt genes and the deletion Δ117 in tcdC (Xpert® C. difficile/Epi). Recurrence was defined as a positive laboratory test result for C. difficile more than 14 days but within 8 weeks after the initial diagnosis date with reappearance of symptoms. To identify factors associated with recurrence in 027+ and 027- CDI, a multivariate analysis was performed in each patient group. Subdistributional hazard ratios (sHRs) and 95% confidence intervals (95%CIs) were calculated.

RESULTS

Overall, 238 patients with 027+ CDI and 267 with 027- CDI were analysed. On multivariate analysis metronidazole monotherapy (sHR 2.380, 95%CI 1.549-3.60, p <0.001) and immunosuppressive treatment (sHR 3.116, 95%CI 1.906-5.090, p <0.001) were factors associated with recurrence in patients with 027+ CDI. In this patient group, metronidazole monotherapy was independently associated with recurrence in both mild/moderate (sHR 1.894, 95%CI 1.051-3.410, p 0.033) and severe CDI (sHR 2.476, 95%CI 1.281-4.790, p 0.007). Conversely, non-severe disease (sHR 3.704, 95%CI 1.437-9.524, p 0.007) and absence of chronic renal failure (sHR 16.129, 95%CI 2.155-125.000, p 0.007) were associated with recurrence in 027- CDI.

CONCLUSIONS

Compared to vancomycin, metronidazole monotherapy appears less effective in curing CDI without relapse in the 027+ patient group, independently of disease severity.

Clinical Practice Guidelines for Clostridium difficile Infection in Adults and Children: 2017 Update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA)

A panel of experts was convened by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) to update the 2010 clinical practice guideline on Clostridium difficile infection (CDI) in adults. The update, which has incorporated recommendations for children (following the adult recommendations for epidemiology, diagnosis, and treatment), includes significant changes in the management of this infection and reflects the evolving controversy over best methods for diagnosis. Clostridium difficile remains the most important cause of healthcare-associated diarrhea and has become the most commonly identified cause of healthcare-associated infection in adults in the United States. Moreover, C. difficile has established itself as an important community pathogen. Although the prevalence of the epidemic and virulent ribotype 027 strain has declined markedly along with overall CDI rates in parts of Europe, it remains one of the most commonly identified strains in the United States where it causes a sizable minority of CDIs, especially healthcare-associated CDIs. This guideline updates recommendations regarding epidemiology, diagnosis, treatment, infection prevention, and environmental management.

Actoxumab + bezlotoxumab combination: what promise for Clostridium difficile treatment?

INTRODUCTION

Clostridium difficile infection (CDI) is the most common healthcare-associated infection worldwide. As standard CDI antibiotic therapies can result in unacceptably high recurrence rates, novel therapeutic strategies for CDI are necessary. A recently emerged immunological therapy is a monoclonal antibody against C. difficile toxin B. Areas covered: In this review, the authors summarize the available pharmacological, preclinical, and clinical data for the CDI treatment based on anti-toxin A (actoxumab) and anti-toxin B (bezlotoxumab) human monoclonal antibodies (HuMabs), and discuss about the potentiality of a therapy that includes HuMab combined administration for CDI. Expert opinion: Although only bezlotoxumab is indicated to reduce recurrence of CDI, experimental studies using a combination of HuMabs actoxumab and bezlotoxumab have shown that bolstering the host immune response against both the C. difficile toxins may be effective in primary and secondary CDI prevention. Besides neutralizing both the key virulence factors, combination of two HuMabs could potentially offer an advantage for a yet to emerge C. difficile strain, which is a steady threat for patients at high risk of CDI. However, as actoxumab development was halted, passive immunotherapy with actoxumab/bezlotoxumab is actually impracticable. Future research will be needed to assess HuMab combination as a therapeutic strategy in clinical and microbiological cure of CDI.

Bezlotoxumab for the prevention of Clostridium difficile recurrence

Clostridium difficile infection is a major economic and clinical burden, due to its high frequency of recurrence. Currently recommended treatments are not efficient for prevention and may contribute to the risk of recurrent infection. In recent years, research has focused on strategies to lessen this risk. Bezlotoxumab is a monoclonal antibody that prevents recurrences of C. difficile infection through the antagonism of toxin B. Areas covered: In this review, the authors discuss the burden of C. difficile infection and its recurrences, the mechanisms underlying the recurrences, and current C. difficile treatments. They subsequently analyze the strategic therapeutic rationale for bezlotoxumab use, as well as the supporting clinical evidence. Expert opinion: Bezlotoxumab is an attractive solution for reducing the unacceptable level of recurrence that occurs with the currently recommended C. difficile treatments and other alternative therapies under consideration. Even though bezlotoxumab has not been tested in large-scale trials exclusively in cases of already established recurrent C.difficile infection (rCDI), it has an advantage over current treatments in that it does not interfere with the patient's gut flora while directly neutralizing the key virulence factor. Although cost remains an important factor against its widespread use, simpler administration, fewer side-effects, and better social acceptability justify its consideration for treating rCDI.

Treatment of pediatric Clostridium difficile infection: a review on treatment efficacy and economic value

The incidence of Clostridium difficile infection (CDI) in pediatric patients continues to rise. Most of the pediatric recommendations for CDI treatment are extrapolated from the literature and guidelines for adults. The American Academy of Pediatrics recommends oral metronidazole as the first-line treatment option for an initial CDI and the first recurrence if they are mild to moderate in severity. Oral vancomycin is recommended to be used for severe CDI and the second recurrent infection. Additional pulsed regimen of oral vancomycin, which is tapered, may increase efficacy in refractory patients. However, there is lack of large studies evaluating the use of fidaxomicin in pediatrics to know whether it could be a safe and effective treatment option for difficult-to-treat patients. Fidaxomicin is associated with higher total drug costs compared to metronidazole and vancomycin, but the literature supports its use due to a lower rate of CDI recurrence, which may result in cost savings. Further studies are warranted to evaluate the use of fidaxomicin in patients <18 years old and to understand its role in the standard of care for pediatric patients with CDI.

Molecular epidemiology of Clostridium difficile infection in a Brazilian cancer hospital

Clostridium difficile is a Gram-positive spore forming anaerobic bacterium and the main cause of healthcare-associated diarrhea. This study aimed to perform the phenotypic characterization and molecular typing of Clostridium difficile isolates among patients at a cancer hospital in Brazil. During 18 months, 48 diarrheic fecal samples were collected, of these 48% were positive in either one or both of the performed tests: detection of toxins A/B and culture. Clostridium difficile was recovered from four samples (17%). All strains carried toxin A and B genes, and the isolates belonged to PCR-ribotype 014/020, PGFE-type NAP4 and toxinotype XVIII. On the other hand, one isolate belonged to a novel PCR-ribotype, and PFGE-type, likewise to toxinotype IXb. The isolates showed susceptibility to metronidazole, vancomycin and moxifloxacin, and were resistant to ciprofloxacin. Finally, the findings indicate high positivity between the samples tested, suggesting an expressive importance of this infection, including detection of a novel ribotype/PFGE-type of Clostridium difficile, and show for the first time the detection of community-associated Clostridium difficile infection (CA-CDI) in these patients in Northeast Brazil. These data emphasize the importance to a better understanding of the epidemiological situation of this infection in Brazilian hospitals.

Impact of Clostridium difficile infection caused by the NAP1/RT027 strain on severity and recurrence during an outbreak and transition to endemicity in a Mexican tertiary care center

OBJECTIVES

To describe the clinical characteristics, outcomes, and factors associated with Clostridium difficile infection (CDI) due to ribotype 027 (RT027) and recurrence, including an outbreak period, with transition to endemicity.

METHODS

A case-control study was performed. Clinical and demographic data were collected for patients with CDI during the period January 2008 to December 2015. Ribotyping of the isolates and PCR for toxin A, B, and binary were performed.

RESULTS

Among 324 episodes of CDI, 27.7% were caused by RT027. Previous fluoroquinolone use (odds ratio (OR) 1.79, 95% confidence interval (CI) 1.01-3.17), previous gastrointestinal endoscopy (OR 2.17, 95% CI 1.29-3.65), chemotherapy (OR 0.43, 95% CI 0.19-0.95), and total enteral nutrition (OR 0.42, 95% CI 0.18-0.97) were associated with RT027. Age >65 years (OR 2.05, 95% CI 1.02-4.10), severe initial episode (OR 3.35, 95% CI 1.60-6.15), previous proton pump inhibitor use (OR 2.34, 95% CI 1.15-4.74), and continued fluoroquinolones (OR 3.08, 95% CI 1.11-8.51) were associated with recurrence. Among the non-RT027, 59.8% were not assigned by the ribotyping database and 50.7% presented binary toxin.

CONCLUSIONS

In this population, CDI due to the RT027 strain was not associated with poorer outcomes. This study reinforces the importance of avoiding fluoroquinolones and PPIs to prevent recurrences. The presence of virulence factors among non-RT027 C. difficile strains underscores the importance of performing molecular epidemiology surveillance.

Thirty-Day Readmissions in Hospitalized Patients Who Received Bezlotoxumab With Antibacterial Drug Treatment for Clostridium difficile Infection

Clinical Trials Registration

NCT01241552 (MODIFY I) and NCT01513239 (MODIFY II).

Clostridium Difficile, Colitis, and Colonoscopy: Pediatric Perspective

PURPOSE OF THE REVIEW

Review tests available for detection of Clostridium difficile (C. Diff) induced disease, including when such tests should be done in children and how they should be interpreted.

RECENT FINDINGS

Multiple tests are available for detecting disease due to C. diff. These include colonoscopy and stool analysis. Colonoscopy with biopsy is the most sensitive test for detecting the presence of colitis. The toxins produced by the C. diff. (toxin A, toxin B, and binary toxin) are the agents that cause injury and disease. Only toxin producing C. diff. Strains will cause disease. Binary toxin by itself is not thought to produce disease. Binary toxin causes disease in humans when present with toxin A and B producing bacteria, and has been implicated with fulminant life threatening disease. Stool analyses vary in sensitivity and specificity depending on the assay used. The presence of toxin producing strains of C diff. in the stool does not equate with disease. The presence of a toxin-producing bacteria or toxins (A or B) only equates with disease if diarrhea or a diseased colon (toxic megacolon, ileus, and sepsis) is present. Nucleic acid amplification testing (NAAT), when used in the stool from patients with diarrhea, appears to be the most efficient study to detect the gene that encodes for toxin A and B and thus to diagnose C. diff.-induced disease. Infants have a high carriage rate of C. diff. and are believed not to develop disease from it or its toxins. Infants should not be tested for C. difficile. The NAAT is most specific when done on patients with diarrhea with liquid stools. Testing for C. difficile should only be done on patients with diarrhea. One can assume that a patient who has no diarrhea and is not ill does not have C. diff.-induced disease. Treatment should be limited to patients with diarrhea who test positive for C. diff. toxin (A or B) or toxin-producing bacteria. Direct testing for binary toxin is not commercially available. Binary toxin is only thought to cause disease in humans when C. diff. toxin (A and B)-producing bacteria are present.

Impact of the NAP-1 strain on disease severity, mortality, and recurrence of healthcare-associated Clostridium difficile infection

OBJECTIVES

Studies are conflicting regarding the association of the North American pulsed-field gel electrophoresis type 1 (NAP1) strain in Clostridium difficile infection (CDI) and outcomes. We evaluated the association of NAP1 with healthcare-associated CDI disease severity, mortality, and recurrence at our academic medical center.

METHODS

Healthcare-associated CDI cases were identified from November 1, 2011 through January 31, 2013. Multivariable regression models were used to evaluate the associations of NAP1 with severe disease (based on the Hines VA severity score index), mortality, and recurrence.

RESULTS

Among 5424 stool specimens submitted to the Clinical Microbiology Laboratory, 292 (5.4%) were positive for C. difficile by polymerase chain reaction (PCR) on or after hospital day 4; 70 (24%) of these specimens also tested positive for NAP1. During the study period, 247 (85%) patients had non-severe disease and 45 (15%) patients had severe disease. Among patients with non-severe disease, 65 (26%) had NAP1 and among patients with severe disease, 5 (11%) had NAP1. After controlling for potential confounders, NAP1 was not associated with an increased likelihood of severe disease (adjusted odds ratio [aOR] = 0.35; 95% confidence interval [CI], 0.13-0.93), in-hospital mortality (aOR = 1.02; 95% CI, 0.53-1.96), or recurrence (aOR = 1.16, 95% CI, 0.36-3.77).

CONCLUSIONS

The NAP1 strain did not increase disease severity, mortality, or recurrence in this study, although the incidence of NAP1-positive healthcare associated-CDI was low. The role of strain typing in outcomes and treatment selection in patients with healthcare-associated CDI remains uncertain.

External Validation of Three Prediction Tools for Patients at Risk of a Complicated Course of Clostridium difficile Infection: Disappointing in an Outbreak Setting

OBJECTIVE Estimating the risk of a complicated course of Clostridium difficile infection (CDI) might help doctors guide treatment. We aimed to validate 3 published prediction models: Hensgens (2014), Na (2015), and Welfare (2011). METHODS The validation cohort comprised 148 patients diagnosed with CDI between May 2013 and March 2014. During this period, 70 endemic cases of CDI occurred as well as 78 cases of CDI related to an outbreak of C. difficile ribotype 027. Model calibration and discrimination were assessed for the 3 prediction rules. RESULTS A complicated course (ie, death, colectomy, or ICU admission due to CDI) was observed in 31 patients (21%), and 23 patients (16%) died within 30 days of CDI diagnosis. The performance of all 3 prediction models was poor when applied to the total validation cohort with an estimated area under the curve (AUC) of 0.68 for the Hensgens model, 0.54 for the Na model, and 0.61 for the Welfare model. For those patients diagnosed with CDI due to non-outbreak strains, the prediction model developed by Hensgens performed the best, with an AUC of 0.78. CONCLUSION All 3 prediction models performed poorly when using our total cohort, which included CDI cases from an outbreak as well as endemic cases. The prediction model of Hensgens performed relatively well for patients diagnosed with CDI due to non-outbreak strains, and this model may be useful in endemic settings. Infect Control Hosp Epidemiol 2017;38:897-905.

IBD: A Growing and Vulnerable Cohort of Hospitalized Patients with Clostridium difficile Infection

The most recent nationwide data show a rising incidence of Clostridium difficile infection in hospitalized patients with ulcerative colitis (UC). We describe recent national trends with regard to incidence, mortality, and the rate of total colectomy. The Nationwide Inpatient Sample database identified patients admitted to hospitals in the United States with diagnoses of C. difficile and inflammatory bowel disease (IBD) during the study years 2007 to 2013. We analyzed incidence of C. difficile, mortality, and colectomy rates. From 2007 to 2013, incidence of patients with IBD admitted with the primary diagnosis of C. difficile rose faster than the non-IBD population (1.24% to 2.14% vs 0.26% to 0.30%, P < 0.0001) and specifically in the UC population rose from 2.36 to 3.48 per cent (P < 0.001). The mortality of non-IBD patients with C. difficile decreased 47 per cent (3.76% to 1.99%, P = 0.003), whereas mortality of IBD patients with C. difficile decreased 54 per cent (6.08% to 2.79%, P = 0.003). For UC patients with primary diagnosis C. difficile, the percentage undergoing total colectomy decreased by 38 per cent (2.47% vs 1.51%, P = 0.049). The incidence of C. difficile continues to rise in the both the IBD and non-IBD population. Our study shows decreasing mortality for IBD and non-IBD patients with C. difficile but a greater decrease in mortality for IBD patients.

Thrombocytopenia in hospitalized patients with severe clostridium difficile infection

Clostridium difficile infection (CDI) is a common cause of nosocomial diarrhea and colitis. The incidence and prognostic significance of thrombocytopenia as related to mode of acquisition (hospital vs. community), NAP1/027 strain, and disease severity has not been examined. We performed a single-institution retrospective analysis of all adult inpatients from 2013 to 2014 diagnosed with CDI during their hospitalization to document the incidence/prevalence of thrombocytopenia and associated outcomes. Severe disease was defined by a composite endpoint of inpatient death, death within 30 days of discharge, presence of septic shock, or need for colectomy during hospitalization. Of the 533 patients diagnosed with CDI, moderate thrombocytopenia (platelet count <100 × 10⁹/L at time of CDI diagnosis) was present in 15 % of the total cohort and incident thrombocytopenia developed in 3 % of patients after admission. Thrombocytopenia was more common in hospital-acquired disease and associated with increased length of stay, but was not associated with treatment failure. Those with moderate thrombocytopenia were more likely to have severe disease, after controlling for white blood cell count, albumin, and creatinine. Moderate thrombocytopenia is associated with poor prognosis and is a potential risk stratification tool for severe CDI.

Clostridium difficile Infection and Patient-Specific Antimicrobial Resistance Testing Reveals a High Metronidazole Resistance Rate

BACKGROUND

Clostridium difficile (CD) infection (CDI) causes marked morbidity and mortality, accounting for large healthcare expenditures annually. Current CDI treatment guidelines focus on clinical markers of patient severity to determine the preferred antibiotic regimen of metronidazole versus vancomycin. The antimicrobial resistance patterns for patients with CD are currently unknown.

AIM

The aim of this study was to define the antimicrobial resistance patterns for CD.

METHODS

This study included all patients with stools sent for CD testing to a private laboratory (DRG Laboratory, Alpharetta, Georgia) in a 6-month period from across the USA. Patient data was de-identified, with only age, gender, and zip-code available per laboratory protocol. All samples underwent PCR testing followed by hybridization for CD toxin regions A and B. Only patients with CD-positive PCR were analyzed. Antimicrobial resistance testing using stool genomic DNA evaluated presence of imidazole- and vancomycin-resistant genes using multiplex PCR gene detection.

RESULTS

Of 2743, 288 (10.5%) stool samples were positive for CD. Six were excluded per protocol. Of 282, 193 (69.4%) were women, and average age was 49.4 ± 18.7 years. Of 282, 62 were PCR positive for toxins A and B, 160 for toxin A positive alone, and 60 for toxin B positive alone. Antimicrobial resistance testing revealed 134/282 (47.5%) patients resistant to imidazole, 17 (6.1%) resistant to vancomycin, and 9 (3.2%) resistant to imidazole and vancomycin.

CONCLUSIONS

CD-positive patients with presence of imidazole-resistant genes from stool DNA extract was a common phenomenon, while vancomycin resistance was uncommon. Similar to treatment of other infections, antimicrobial resistance testing should play a role in CDI clinical decision-making algorithms to enable more expedited and cost-effective delivery of patient care.

Evaluation of Risk Factors for Clostridium difficile Infection in Hematopoietic Stem Cell Transplant Recipients

STUDY OBJECTIVES

The primary objective was to determine the impact of hematologic malignancies and/or conditioning regimens on the risk of developing Clostridium difficile infection (CDI) in patients undergoing hematopoietic stem cell transplantation (HSCT). Secondary objectives were to determine if traditional CDI risk factors applied to patients undergoing HSCT and to determine the presence of CDI markers of severity of illness among this patient population.

DESIGN

Single-center retrospective case-control study.

SETTING

Quaternary care academic medical center.

PATIENTS

A total of 105 patients who underwent HSCT between December 2009 and December 2014; of these patients, 35 developed an initial episode of CDI (HSCT/CDI group [cases]), and 70 did not (controls). Controls were matched in a 2:1 ratio to cases based on age (± 10 yrs) and date of HSCT (± 6 mo).

MEASUREMENTS AND MAIN RESULTS

Baseline characteristics of the two groups were well balanced regarding age, sex, race, ethnicity, and type of HSCT. No significant differences in conditioning regimen, hematologic malignancy, total body irradiation received for HSCT, use of antibiotics within 60 days of HSCT, or use of prophylactic antibiotics after HSCT were noted between the two groups. Patients in the control group were 10.57 (95% confidence interval 1.24-492.75) more likely to have received corticosteroids prior to HSCT than patients in the HSCT/CDI group (p=0.01). Use of proton pump inhibitors at the time of HSCT was greater among the control group than among patients in the HSCT/CDI group (97% vs 86%, p=0.048). No significant difference in mortality was noted between the groups at 3, 6, and 12 months after HSCT. Metronidazole was frequently prescribed for patients in the HSCT/CDI group (34 patients [97%]). Severe CDI was not common among patients within the HSCT/CDI group (13 patients [37%]); vancomycin was infrequently prescribed for these patients ([31%] 4/13 patients).

CONCLUSION

Hematologic malignancies and a conditioning regimen administered for HSCT were not significant risk factors for the development of CDI after HSCT. Use of corticosteroids prior to HSCT and use of proton pump inhibitors at the time of HSCT were associated with a significantly decreased risk of CDI.

Clostridium difficile

Clostridium difficile infections (CDIs) have emerged as one of the principal threats to the health of hospitalized and immunocompromised patients. The importance of C difficile colonization is increasingly recognized not only as a source for false-positive clinical testing but also as a source of new infections within hospitals and other health care environments. In the last five years, several new treatment strategies that capitalize on the increasing understanding of the altered microbiome and host defenses in patients with CDI have completed clinical trials, including fecal microbiota transplantation. This article highlights the changing epidemiology, laboratory diagnostics, pathogenesis, and treatment of CDI.

Clostridium difficile Infection: An Orthopaedic Surgeon's Guide to Epidemiology, Management, and Prevention

Clostridium difficile infection is a growing concern in health care and is a worrisome complication in orthopaedics. The incidence and severity of this infection are increasing, although the incidence following orthopaedic surgery is comparatively lower than that seen in patients in most other surgical specialties. The typical geriatric orthopaedic patient may have many risk factors that increase the likelihood of C difficile infection, including advanced age, residence in a long-term care facility, multiple comorbidities, the use of perioperative antibiotics, and a long length of stay. Many antibiotics used for prophylaxis in orthopaedic procedures have been correlated with an increased incidence of C difficile infection. The indications for C difficile testing may vary, and diagnostic methods differ in sensitivity and specificity. The prevention of this infection is multifaceted and consists of practitioner and patient hand hygiene, antibiotic stewardship, contact precautions, and proper environmental cleaning. The main treatment options are metronidazole for mild cases and vancomycin for moderate to severe disease. Up to 40% of cases may have one or more recurrence. Further research is needed to identify novel therapeutic and prevention strategies for C difficile infection.

A genetic switch controls the production of flagella and toxins in Clostridium difficile

In the human intestinal pathogen Clostridium difficile, flagella promote adherence to intestinal epithelial cells. Flagellar gene expression also indirectly impacts production of the glucosylating toxins, which are essential to diarrheal disease development. Thus, factors that regulate the expression of the flgB operon will likely impact toxin production in addition to flagellar motility. Here, we report the identification a "flagellar switch" that controls the phase variable production of flagella and glucosylating toxins. The flagellar switch, located upstream of the flgB operon containing the early stage flagellar genes, is a 154 bp invertible sequence flanked by 21 bp inverted repeats. Bacteria with the sequence in one orientation expressed flagellum and toxin genes, produced flagella, and secreted the toxins ("flg phase ON"). Bacteria with the sequence in the inverse orientation were attenuated for flagellar and toxin gene expression, were aflagellate, and showed decreased toxin secretion ("flg phase OFF"). The orientation of the flagellar switch is reversible during growth in vitro. We provide evidence that gene regulation via the flagellar switch occurs post-transcription initiation and requires a C. difficile-specific regulatory factor to destabilize or degrade the early flagellar gene mRNA when the flagellar switch is in the OFF orientation. Lastly, through mutagenesis and characterization of flagellar phase locked isolates, we determined that the tyrosine recombinase RecV, which catalyzes inversion at the cwpV switch, is also responsible for inversion at the flagellar switch in both directions. Phase variable flagellar motility and toxin production suggests that these important virulence factors have both advantageous and detrimental effects during the course of infection.

Bezlotoxumab for Prevention of Recurrent Clostridium difficile Infection

BACKGROUND

Clostridium difficile is the most common cause of infectious diarrhea in hospitalized patients. Recurrences are common after antibiotic therapy. Actoxumab and bezlotoxumab are human monoclonal antibodies against C. difficile toxins A and B, respectively.

METHODS

We conducted two double-blind, randomized, placebo-controlled, phase 3 trials, MODIFY I and MODIFY II, involving 2655 adults receiving oral standard-of-care antibiotics for primary or recurrent C. difficile infection. Participants received an infusion of bezlotoxumab (10 mg per kilogram of body weight), actoxumab plus bezlotoxumab (10 mg per kilogram each), or placebo; actoxumab alone (10 mg per kilogram) was given in MODIFY I but discontinued after a planned interim analysis. The primary end point was recurrent infection (new episode after initial clinical cure) within 12 weeks after infusion in the modified intention-to-treat population.

RESULTS

In both trials, the rate of recurrent C. difficile infection was significantly lower with bezlotoxumab alone than with placebo (MODIFY I: 17% [67 of 386] vs. 28% [109 of 395]; adjusted difference, -10.1 percentage points; 95% confidence interval [CI], -15.9 to -4.3; P<0.001; MODIFY II: 16% [62 of 395] vs. 26% [97 of 378]; adjusted difference, -9.9 percentage points; 95% CI, -15.5 to -4.3; P<0.001) and was significantly lower with actoxumab plus bezlotoxumab than with placebo (MODIFY I: 16% [61 of 383] vs. 28% [109 of 395]; adjusted difference, -11.6 percentage points; 95% CI, -17.4 to -5.9; P<0.001; MODIFY II: 15% [58 of 390] vs. 26% [97 of 378]; adjusted difference, -10.7 percentage points; 95% CI, -16.4 to -5.1; P<0.001). In prespecified subgroup analyses (combined data set), rates of recurrent infection were lower in both groups that received bezlotoxumab than in the placebo group in subpopulations at high risk for recurrent infection or for an adverse outcome. The rates of initial clinical cure were 80% with bezlotoxumab alone, 73% with actoxumab plus bezlotoxumab, and 80% with placebo; the rates of sustained cure (initial clinical cure without recurrent infection in 12 weeks) were 64%, 58%, and 54%, respectively. The rates of adverse events were similar among these groups; the most common events were diarrhea and nausea.

CONCLUSIONS

Among participants receiving antibiotic treatment for primary or recurrent C. difficile infection, bezlotoxumab was associated with a substantially lower rate of recurrent infection than placebo and had a safety profile similar to that of placebo. The addition of actoxumab did not improve efficacy. (Funded by Merck; MODIFY I and MODIFY II ClinicalTrials.gov numbers, NCT01241552 and NCT01513239 .).

Cost analysis of an outbreak of Clostridium difficile infection ribotype 027 in a Dutch tertiary care centre

BACKGROUND

The economic impact of Clostridium difficile infection (CDI) on the healthcare system is significant. From May 2013 to May 2014, an outbreak of C. difficile ribotype 027 occurred in a Dutch tertiary care hospital, involving 72 patients. The primary aim of this study was to provide insight into the financial burden that this CDI outbreak brought upon this hospital.

METHODS

A retrospective analysis was performed to estimate the costs of a one-year-long C. difficile ribotype 027 outbreak. Medical charts were reviewed for patient data. In addition, all costs associated with the outbreak control measures were collected.

FINDINGS

The attributable costs of the whole outbreak were estimated to be €1,222,376. The main contributing factor was missed revenue due to increased length of stay of CDI patients and closure of beds to enable contact isolation of CDI patients (36%). A second important cost component was extra surveillance and activities of the Department of Medical Microbiology and Infection Control (25%).

CONCLUSION

To the authors' knowledge, this is the first study to provide insight into the attributable costs of CDI in an outbreak setting, and to delineate the major cost items. It is clear that the economic consequences of CDI are significant. The high costs associated with a CDI outbreak should help to justify the use of additional resources for CDI prevention and control.

Clinical Characteristics and Treatment Outcomes of Clostridium difficile Infections by PCR Ribotype 017 and 018 Strains

The objective of this study was to identify the clinical characteristics of Clostridium difficile infections (CDIs) caused by toxin A-negative/toxin B-positive (A-B+) PCR ribotype 017 (R017) and A+B+ ribotype 018 (R018) strains, prevalent in Asian countries. From February 2010 through January 2013, all CDI patients in our hospital were enrolled; their medical records were retrospectively reviewed, and the isolates were characterized by toxigenic culture and PCR ribotyping. Based on the ribotypes, a total of 510 cases were categorized as R017 (139, 27.3%), R018 (157, 30.8%) and other ribotypes groups (214, 42.0%), and clinical variables were compared between R017 and other ribotypes, R018 and other ribotypes and R018 and R017 groups. The patients with R017 infections had a higher mean Charlson's comorbidity index (OR 1.1, 1-1.21, p = 0.05), lower serum albumin (OR 0.47, 0.31-0.73, p = 0.001) and lower CRP levels (OR 0.96, 0.92-0.99, p = 0.022) than those with other ribotypes. R018 infections caused more azotemia (OR 4.06, 1.28-12.91, p = 0.018) and more frequent severe CDI (OR 1.87, 1.12-3.13, p = 0.016) than the other ribotypes infections. R017 and R018 infections were more often associated with toxin positive stools (OR 2.94, 1.65-4.09, p<0.001; OR 4.55, 2.82-7.33, p<0.001). In terms of treatment outcomes, R017 infections caused a marginally higher 30-day mortality than other ribotypes infection. In a final multiple logistic regression model, 30-day mortality was associated with leukocytosis (OR 2.45, 1.0-6.01, p = 0.05) and hypoalbuminemia (OR 4.57, 1.83-11.39, p = 0.001), but only marginally with R017 infection (OR 2.14, 0.88-5.22, p = 0.094). In conclusion, infections by C. difficile R018 strains tend to cause more severe disease, while there was a trend for higher mortality with R017 infections.

Mathematical Modeling of the Transmission Dynamics of Clostridium difficile Infection and Colonization in Healthcare Settings: A Systematic Review

BACKGROUND

We conducted a systematic review of mathematical models of transmission dynamic of Clostridium difficile infection (CDI) in healthcare settings, to provide an overview of existing models and their assessment of different CDI control strategies.

METHODS

We searched MEDLINE, EMBASE and Web of Science up to February 3, 2016 for transmission-dynamic models of Clostridium difficile in healthcare settings. The models were compared based on their natural history representation of Clostridium difficile, which could include health states (S-E-A-I-R-D: Susceptible-Exposed-Asymptomatic-Infectious-Resistant-Deceased) and the possibility to include healthcare workers and visitors (vectors of transmission). Effectiveness of interventions was compared using the relative reduction (compared to no intervention or current practice) in outcomes such as incidence of colonization, CDI, CDI recurrence, CDI mortality, and length of stay.

RESULTS

Nine studies describing six different models met the inclusion criteria. Over time, the models have generally increased in complexity in terms of natural history and transmission dynamics and number/complexity of interventions/bundles of interventions examined. The models were categorized into four groups with respect to their natural history representation: S-A-I-R, S-E-A-I, S-A-I, and S-E-A-I-R-D. Seven studies examined the impact of CDI control strategies. Interventions aimed at controlling the transmission, lowering CDI vulnerability and reducing the risk of recurrence/mortality were predicted to reduce CDI incidence by 3-49%, 5-43% and 5-29%, respectively. Bundles of interventions were predicted to reduce CDI incidence by 14-84%.

CONCLUSIONS

Although CDI is a major public health problem, there are very few published transmission-dynamic models of Clostridium difficile. Published models vary substantially in the interventions examined, the outcome measures used and the representation of the natural history of Clostridium difficile, which make it difficult to synthesize results and provide a clear picture of optimal intervention strategies. Future modeling efforts should pay specific attention to calibration, structural uncertainties, and transparent reporting practices.

Growth Patterns of Clostridium difficile - Correlations with Strains, Binary Toxin and Disease Severity: A Prospective Cohort Study

A broad spectrum of symptoms has been associated with C. difficile infection (CDI). Several studies indicate that toxin-production correlates with growth rates of C. difficile. This study aimed to correlate growth rates of C. difficile with disease severity and strain characteristics. From 01/2003 to 10/2011, strains from a prospective cohort of all inpatients with CDI at the University Hospital Basel, Switzerland were analyzed regarding binary toxin, presence of the tcdC deletion and ribotype. Isothermal microcalorimetry was performed to determine growth rates, quantified by the Gompertz function. Ordered logistic regression models were used to correlate disease severity with strain features and clinical characteristics. Among 199 patients, 31 (16%) were infected with binary toxin-producing strains, of which the tcdC gene-deletion nt117 was detected in 9 (4%). Disease severity was classified as mild in 130 patients (65.3%), as severe in 59 patients (29.7%) and as severe/complicated in 10 patients (5.0%). Growth rates were inversely associated with disease severity in univariable (OR 0.514, 95%CI 0.29–0.91, p = 0.023) and multivariable analyses (OR 0.51, 95%CI 0.26–0.97, p = 0.040). While none of the strain characteristics such as presence of the tcdC gene deletion or binary toxin predicted CDI severity, growth rates were inversely correlated with disease severity. Further investigations are needed to analyze growth-regulators and respective correlations with the level of toxin production in C. difficile, which may be important determinants of disease severity.

An exploratory study to evaluate Clostridium difficile polymerase chain reaction ribotypes and infection outcomes

BACKGROUND

Clostridium difficile infection ranges from mild to severe prolonged diarrhea with systemic symptoms. Previous studies have assessed the correlation of some disease severity parameters to C. difficile ribotypes. However, certain clinical parameters of interest have not yet been evaluated.

AIM

We conducted an exploratory study to evaluate the correlation of C. difficile ribotypes to parameters not assessed previously, notably days to diarrhea resolution (in terms of days to formed stools and days to less than three stools per day), length of hospital stay, 30-day recurrence rates, and 30-day readmission rates. Additional severity parameters evaluated include leukocytosis, serum creatinine, fever, and nausea/vomiting.

METHODS

Polymerase chain reaction ribotyping was performed on C. difficile isolates from baseline stool samples of 29 patients. A retrospective chart review was conducted to assess the parameters of interest.

RESULTS

The most common ribotypes were 027 (38%), 014/020 (21%), and 106/174 (21%). Numerically, 027 ribotype patients required more days to less than three stools per day versus 014/020 and 106/174 ribotype patients (P=0.2). The three ribotypes were similar regarding time to formed stools, duration of hospitalization, and 30-day readmission rate (P=0.2, 0.6, and 0.8, respectively). Recurrence within 30 days occurred in two patients with 027 and two patients with 014/020 (P=0.6). Leukocytosis and fever were more prominent with 027 than with 014/020 and 106/174 (P=0.04 for both parameters), although the degree of nausea/vomiting did not differ between the three groups (P=0.3). A serum creatinine level ≥1.5 times the premorbid level was seen in only three patients, each infected with a different ribotype.

CONCLUSION

Although these data provide a baseline assessment of outcomes to aid in the design of future studies, the diversity of C. difficile ribotypes within the population must be considered, and additional work with other ribotypes may further explain the association with these outcomes.

Evaluating Epidemiology and Improving Surveillance of Infections Associated with Health Care, United States

This national resource provides much-needed data on pathogens, infections, and antimicrobial drug use.

The Healthcare-Associated Infections Community Interface (HAIC), launched in 2009, is the newest major activity of the Emerging Infections Program. The HAIC activity addresses population- and laboratory-based surveillance for Clostridium difficile infections, candidemia, and multidrug-resistant gram-negative bacilli. Other activities include special projects: the multistate Healthcare-Associated Infections and Antimicrobial Use Prevalence Survey and projects that evaluate new approaches for improving surveillance. The HAIC activity has provided information about the epidemiology and adverse health outcomes of health care–associated infections and antimicrobial drug use in the United States and informs efforts to improve patient safety through prevention of these infections.

Fecal microbiota transplantation for recurrent Clostridium difficile infection: The patient experience

BACKGROUND

Although effectiveness of fecal microbiota transplantation (FMT) has been adequately documented, the patient experience of undergoing FMT has not.

METHODS

We carried out a qualitative interview study using semistructured questions relating to aspects of health pre-FMT, during FMT, and post-FMT periods with 17 participants. Inductive coding was used to identify core themes during the periods.

RESULTS

Pre-FMT themes included physical (continuous diarrhea and weight loss), mental (depression, wanting to die, and fear), quality of life (unable to perform normal activities), social support, and financial (medication costs) factors. Provider resistance/limited awareness were barriers to FMT. Participants reached a tipping point, experiencing feelings of hopelessness, which led them to pursue FMT. During FMT, participants commented on lack of a so-called ick factor. During the posttreatment period, participants experienced symptom relief, but had residual fears. Patient activation was present during all phases, including information seeking and empowerment.

CONCLUSIONS

During the pre-FMT period, participants experienced extreme discomfort and encountered FMT barriers. Undergoing FMT was reported as easy but residual fear remained. There were displays of patient activation at all FMT time periods, including the seeking of FMT. Participants could have benefited from having undergone FMT sooner, demonstrating a need for improvement in provider education and health system barriers regarding FMT.

Infectious Diarrhea: Norovirus and Clostridium difficile in Older Adults

Norovirus infection usually results in acute gastroenteritis, often with incapacitating nausea, vomiting, and diarrhea. It is highly contagious and resistant to eradication with alcohol-based hand sanitizer. Appropriate preventative and infection control measures can mitigate the morbidity and mortality associated with norovirus infection. Clostridium difficile infection is the leading cause of health care-associated diarrhea in the United States. Antibiotic use is by far the most common risk factor for C difficile colonization and infection. Appropriate preventive measures and judicious use of antibiotics can help mitigate the morbidity and mortality associated with C difficile infection.