Sauver JL, Harmsen WS, Zinsmeister AR. The epidemiology of community-acquired Clostridium difficile infection: a population-based study

OBJECTIVES

Clostridium difficile infection (CDI) is a common hospital-acquired infection with increasing incidence, severity, recurrence, and associated morbidity and mortality. There are emerging data on the occurrence of CDI in nonhospitalized patients. However, there is a relative lack of community-based CDI studies, as most of the existing studies are hospital based, potentially influencing the results by referral or hospitalization bias by missing cases of community-acquired CDI.

METHODS

To better understand the epidemiology of community-acquired C. difficile infection, a population-based study was conducted in Olmsted County, Minnesota, using the resources of the Rochester Epidemiology Project. Data regarding severity, treatment response, and outcomes were compared in community-acquired vs. hospital-acquired cohorts, and changes in these parameters, as well as in incidence, were assessed over the study period.

RESULTS

Community-acquired CDI cases accounted for 41% of 385 definite CDI cases. The incidence of both community-acquired and hospital-acquired CDI increased significantly over the study period. Compared with those with hospital-acquired infection, patients with community-acquired infection were younger (median age 50 years compared with 72 years), more likely to be female (76% vs. 60%), had lower comorbidity scores, and were less likely to have severe infection (20% vs. 31%) or have been exposed to antibiotics (78% vs. 94%). There were no differences in the rates of complicated or recurrent infection in patients with community-acquired compared with hospital-acquired infection.

CONCLUSIONS

In this population-based cohort, a significant proportion of cases of CDI occurred in the community. These patients were younger and had less severe infection than those with hospital-acquired infection. Thus, reports of CDI in hospitalized patients likely underestimate the burden of disease and overestimate severity.

A Novel Microbiome Therapeutic Increases Gut Microbial Diversity and Prevents Recurrent Clostridium difficile Infection

BACKGROUND

Patients with recurrent Clostridium difficile infection (CDI) have a ≥60% risk of relapse, as conventional therapies do not address the underlying gastrointestinal dysbiosis. This exploratory study evaluated the safety and efficacy of bacterial spores for preventing recurrent CDI.

METHODS

Stool specimens from healthy donors were treated with ethanol to eliminate pathogens. The resulting spores were fractionated and encapsulated for oral delivery as SER-109. Following their response to standard-of-care antibiotics, patients in cohort 1 were treated with SER-109 on 2 consecutive days (geometric mean dose, 1.7 × 10(9) spores), and those in cohort 2 were treated on 1 day (geometric mean dose, 1.1 × 10(8) spores). The primary efficacy end point was absence of C. difficile-positive diarrhea during an 8-week follow-up period. Microbiome alterations were assessed.

RESULTS

Thirty patients (median age, 66.5 years; 67% female) were enrolled, and 26 (86.7%) met the primary efficacy end point. Three patients with early, self-limiting C. difficile-positive diarrhea did not require antibiotics and tested negative for C. difficile at 8 weeks; thus, 96.7% (29 of 30) achieved clinical resolution. In parallel, gut microbiota rapidly diversified, with durable engraftment of spores and no outgrowth of non-spore-forming bacteria found after SER-109 treatment. Adverse events included mild diarrhea, abdominal pain, and nausea.

CONCLUSIONS

SER-109 successfully prevented CDI and had a favorable safety profile, supporting a novel microbiome-based intervention as a potential therapy for recurrent CDI.

The epidemiology of Clostridium difficile infection in children: a population-based study

BACKGROUND

The incidence of Clostridium difficile infection (CDI) is increasing, even in populations previously thought to be at low risk, including children. Most incidence studies have included only hospitalized patients and are thus potentially influenced by referral or hospitalization biases.

METHODS

We performed a population-based study of CDI in pediatric residents (aged 0-18 years) of Olmsted County, Minnesota, from 1991 through 2009 to assess the incidence, severity, treatment response, and outcomes of CDI.

RESULTS

We identified 92 patients with CDI, with a median age of 2.3 years (range, 1 month-17.6 years). The majority of cases (75%) were community-acquired. The overall age- and sex-adjusted CDI incidence was 13.8 per 100 000 persons, which increased 12.5-fold, from 2.6 (1991-1997) to 32.6 per 100 000 (2004-2009), over the study period (P < .0001). The incidence of community-acquired CDI was 10.3 per 100 000 persons and increased 10.5-fold, from 2.2 (1991-1997) to 23.4 per 100 000 (2004-2009) (P < .0001). Severe, severe-complicated, and recurrent CDI occurred in 9%, 3%, and 20% of patients, respectively. The initial treatment in 82% of patients was metronidazole, and 18% experienced treatment failure. In contrast, the initial treatment in 8% of patients was vancomycin and none of them failed therapy.

CONCLUSIONS

In this population-based cohort, CDI incidence in children increased significantly from 1991 through 2009. Given that the majority of cases were community-acquired, estimates of the incidence of CDI that include only hospitalized children may significantly underestimate the burden of disease in children.

Efficacy and Safety of RBX2660 in PUNCH CD3, a Phase III, Randomized, Double-Blind, Placebo-Controlled Trial with a Bayesian Primary Analysis for the Prevention of Recurrent Clostridioides difficile Infection

BACKGROUND

Recurrent Clostridioides difficile infection, associated with dysbiosis of gut microbiota, has substantial disease burden in the USA. RBX2660 is a live biotherapeutic product consisting of a broad consortium of microbes prepared from human stool that is under investigation for the reduction of recurrent C. difficile infection.

METHODS

A randomized, double-blind, placebo-controlled, phase III study, with a Bayesian primary analysis integrating data from a previous phase IIb study, was conducted. Adults who had one or more C. difficile infection recurrences with a positive stool assay for C. difficile and who were previously treated with standard-of-care antibiotics were randomly assigned 2:1 to receive a subsequent blinded, single-dose enema of RBX2660 or placebo. The primary endpoint was treatment success, defined as the absence of C. difficile infection diarrhea within 8 weeks of study treatment.

RESULTS

Of the 320 patients screened, 289 were randomly assigned and 267 received blinded treatment (n = 180, RBX2660; n = 87, placebo). Original model estimates of treatment success were 70.4% versus 58.1% with RBX2660 and placebo, respectively. However, after aligning the data to improve the exchangeability and interpretability of the Bayesian analysis, the model-estimated treatment success rate was 70.6% with RBX2660 versus 57.5% with placebo, with an estimated treatment effect of 13.1% and a posterior probability of superiority of 0.991. More than 90% of the participants who achieved treatment success at 8 weeks had sustained response through 6 months in both the RBX2660 and the placebo groups. Overall, RBX2660 was well tolerated, with manageable adverse events. The incidence of treatment-emergent adverse events was higher in RBX2660 recipients compared with placebo and was mostly driven by a higher incidence of mild gastrointestinal events.

CONCLUSIONS

RBX2660 is a safe and effective treatment to reduce recurrent C. difficile infection following standard-of-care antibiotics with a sustained response through 6 months.

CLINICAL TRIAL REGISTRATION

NCT03244644; 9 August, 2017.

The growing incidence and severity of Clostridium difficile infection in inpatient and outpatient settings

Clostridium difficile infection (CDI) is a leading cause of nosocomial infections, with disease severity ranging from mild diarrhea to fulminant colitis. The incidence and severity of CDI has been on the rise over the last 10-20 years, with CDI being increasingly described outside healthcare settings and in populations previously thought to be at low risk. There has also been an increase in the morbidity, mortality and economic burden associated with CDI in the last several years. This increasing incidence and severity is thought to be at least partially due to frequent antibiotic use and the emergence of a hypervirulent C. difficile strain.

A clinician's primer on the role of the microbiome in human health and disease

The importance of the commensal microbiota that colonizes the skin, gut, and mucosal surfaces of the human body is being increasingly recognized through a rapidly expanding body of science studying the human microbiome. Although, at first glance, these discoveries may seem esoteric, the clinical implications of the microbiome in human health and disease are becoming clear. As such, it will soon be important for practicing clinicians to have an understanding of the basic concepts of the human microbiome and its relation to human health and disease. In this Concise Review, we provide a brief introduction to clinicians of the concepts underlying this burgeoning scientific field and briefly explore specific disease states for which the potential role of the human microbiome is becoming increasingly evident, including Clostridium difficile infection, inflammatory bowel disease, colonization with multidrug-resistant organisms, obesity, allergic diseases, autoimmune diseases, and neuropsychiatric illnesses, and we also discuss current and future roles of microbiome restorative therapies.

Changes in microbial ecology after fecal microbiota transplantation for recurrent C. difficile infection affected by underlying inflammatory bowel disease

BACKGROUND

Gut microbiota play a key role in maintaining homeostasis in the human gut. Alterations in the gut microbial ecosystem predispose to Clostridium difficile infection (CDI) and gut inflammatory disorders such as inflammatory bowel disease (IBD). Fecal microbiota transplantation (FMT) from a healthy donor can restore gut microbial diversity and pathogen colonization resistance; consequently, it is now being investigated for its ability to improve inflammatory gut conditions such as IBD. In this study, we investigated changes in gut microbiota following FMT in 38 patients with CDI with or without underlying IBD.

RESULTS

There was a significant change in gut microbial composition towards the donor microbiota and an overall increase in microbial diversity consistent with previous studies after FMT. FMT was successful in treating CDI using a diverse set of donors, and varying degrees of donor stool engraftment suggesting that donor type and degree of engraftment are not drivers of a successful FMT treatment of CDI. However, patients with underlying IBD experienced an increased number of CDI relapses (during a 24-month follow-up) and a decreased growth of new taxa, as compared to the subjects without IBD. Moreover, the need for IBD therapy did not change following FMT. These results underscore the importance of the existing gut microbial landscape as a decisive factor to successfully treat CDI and potentially for improvement of the underlying pathophysiology in IBD.

CONCLUSIONS

FMT leads to a significant change in microbial diversity in patients with recurrent CDI and complete resolution of symptoms. Stool donor type (related or unrelated) and degree of engraftment are not the key for successful treatment of CDI by FMT. However, CDI patients with IBD have higher proportion of the original community after FMT and lack of improvement of their IBD symptoms and increased episodes of CDI on long-term follow-up.

Clostridium difficile infection: new insights into management

Clostridium difficile was first described as a cause of diarrhea in 1978 and is now among the leading 3 hospital-acquired infections in the United States, along with methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. In the past 2 decades, there has been an increase in the incidence, severity, and recurrence rates of C difficile infection, all of which are associated with poor outcomes. In addition, several novel risk factors and newer treatment methods are emerging, including fidaxomicin therapy, treatment using monoclonal antibodies, and fecal microbiota transplantation, that have shown promise for the treatment of C difficile infection. This review focuses on the changing epidemiology, risk factors, and newer methods for treatment of C difficile infection.

Management of Clostridium difficile Infection in Inflammatory Bowel Disease: Expert Review from the Clinical Practice Updates Committee of the AGA Institute

The purpose of this expert review is to synthesize the existing evidence on the management of Clostridium difficile infection in patients with underlying inflammatory bowel disease. The evidence reviewed in this article is a summation of relevant scientific publications, expert opinion statements, and current practice guidelines. This review is a summary of expert opinion in the field without a formal systematic review of evidence. Best Practice Advice 1: Clinicians should test patients who present with a flare of underlying inflammatory bowel disease for Clostridium difficile infection. Best Practice Advice 2: Clinicians should screen for recurrent C difficile infection if diarrhea or other symptoms of colitis persist or return after antibiotic treatment for C difficile infection. Best Practice Advice 3: Clinicians should consider treating C difficile infection in inflammatory bowel disease patients with vancomycin instead of metronidazole. Best Practice Advice 4: Clinicians strongly should consider hospitalization for close monitoring and aggressive management for inflammatory bowel disease patients with C difficile infection who have profuse diarrhea, severe abdominal pain, a markedly increased peripheral blood leukocyte count, or other evidence of sepsis. Best Practice Advice 5: Clinicians may postpone escalation of steroids and other immunosuppression agents during acute C difficile infection until therapy for C difficile infection has been initiated. However, the decision to withhold or continue immunosuppression in inflammatory bowel disease patients with C difficile infection should be individualized because there is insufficient existing robust literature on which to develop firm recommendations. Best Practice Advice 6: Clinicians should offer a referral for fecal microbiota transplantation to inflammatory bowel disease patients with recurrent C difficile infection.

Gut microbiome predictors of treatment response and recurrence in primary Clostridium difficile infection

BACKGROUND

Clostridium difficile infection (CDI) may not respond to initial therapy and frequently recurs, but predictors of response and recurrence are inconsistent. The impact of specific alterations in the gut microbiota determining treatment response and recurrence in patients with CDI is unknown.

AIM

To assess microbial signatures as predictors of treatment response and recurrence in CDI.

METHODS

Pre-treatment stool samples and clinical metadata including outcomes were collected prospectively from patients with their first CDI episode. Next generation 16s rRNA sequencing using MiSeq Illumina platform was performed and changes in microbial community structure were correlated with CDI outcomes.

RESULTS

Eighty-eight patients (median age 52.7 years, 60.2% female) were included. Treatment failure occurred in 12.5% and recurrence after response in 28.5%. Patients who responded to treatment had an increase in Ruminococcaceae, Rikenellaceae, Clostridiaceae, Bacteroides, Faecalibacterium and Rothia compared to nonresponders. A risk-index built from this panel of microbes differentiated responders (mean 0.07 ± 0.24) from nonresponders (0.52 ± 0.42; P = 0.0002). Receiver operating characteristic (ROC) curve demonstrated that risk-index was a strong predictor of treatment response with an area under the curve (AUC) of 0.85. Among clinical parameters tested, only proton pump inhibitor use predicted recurrent CDI (OR 3.75, 95% CI 1.27-11.1, P = 0.01). Patients with recurrent CDI had statistically significant increases in Veillonella, Enterobacteriaceae, Streptococci, Parabacteroides and Lachnospiraceae compared to patients without recurrence and a risk index was able to predict recurrence (AUC = 0.78).

CONCLUSION

Gut microbiota signatures predict treatment response and recurrence potentially, allowing identification of patients with Clostridium difficile infection that may benefit from early institution of alternate therapies.

Outcomes in community-acquired Clostridium difficile infection

BACKGROUND

Community-acquired Clostridium difficile infection (CA-CDI) is an increasingly appreciated condition. It is being described in populations lacking traditional predisposing factors that have been previously considered at low-risk for this infection. As most studies of CDI are hospital-based, outcomes in these patients are not well known.

AIM

To examine outcomes and their predictors in patients with CA-CDI.

METHODS

A sub-group analysis of a population-based epidemiological study of CDI in Olmsted county, Minnesota from 1991-2005 was performed. Data regarding outcomes, including severity, treatment response, need for hospitalisation and recurrence were analysed.

RESULTS

Of 157 CA-CDI cases, the median age was 50 years and 75.3% were female. Among all CA-CDI cases, 40% required hospitalisation, 20% had severe and 4.4% had severe-complicated infection, 20% had treatment failure and 28% had recurrent CDI. Patients who required hospitalisation were significantly older (64 years vs. 44 years, P < 0.001), more likely to have severe disease (33.3% vs. 11.7%, P = 0.001), and had higher mean Charlson comorbidity index scores (2.06 vs. 0.84, P = 0.001). They had similar treatment failure and recurrence rates as patients who did not require hospitalisation.

CONCLUSIONS

Community-acquired Clostridium difficile infection can be associated with complications and poor outcomes, including hospitalisation and severe Clostridium difficile infection. As the incidence of community-acquired Clostridium difficile infection increases, clinicians should be aware of risk factors (increasing age, comorbid conditions and disease severity) that predict the need for hospitalisation and complications in patients with community-acquired Clostridium difficile infection.

The relationship between disease activity and quality of life in systemic lupus erythematosus

OBJECTIVE

To determine the quality of life (QOL) in SLE patients and correlate it with disease activity.

METHODS

Lupus patients fulfilling the ACR 1997 criteria for SLE were included in this cross-sectional study. Patients were administered the World Health Organization Quality of Life-Bref (WHOQOL-Bref) to assess their quality of life. Disease activity was measured using Mexican Systemic Lupus Erythematosus Disease Activity Index (Mex-SLEDAI).

RESULTS

The study group comprised 73 lupus patients (70 females and three males) with mean age 35.22 +/- 11.15 yr and mean disease duration 5.62 +/- 5.14 yr. Mean Mex-SLEDAI score was 3.31 +/- 3.19. Higher disease activity scores were associated with lower QOL scores in the physical (P = 0.001) and psychological domains (P = 0.01) but showed no significant correlation with the domains of social and environmental QOL. Patients with clearly active and probably active disease showed significantly lower scores in the physical (P = 0.01) and psychological (P = 0.02) domains than patients with inactive disease. However, no significant difference was found in the domains of social and environmental QOL. Age or disease duration did not affect the QOL in any of the domains.

CONCLUSIONS

Physical and psychological QOL are impaired to a larger extent in active lupus. However, social and environmental QOL do not correlate with the disease activity status in lupus patients.

Gastric acid suppression and outcomes in Clostridium difficile infection: a population-based study

OBJECTIVE

To evaluate the association of gastric acid suppression medications, including proton pump inhibitors and histamine type 2 blockers, with outcomes in patients with Clostridium difficile infection (CDI) in a population-based cohort.

PATIENTS AND METHODS

To understand the association between acid suppression and outcomes in patients with CDI, we conducted a population-based study in Olmsted County, Minnesota, from January 1, 1991, through December 31, 2005. We compared demographic data and outcomes, including severe, severe-complicated, and recurrent CDI and treatment failure, in a cohort of patients with CDI who were treated with acid suppression medications with these outcomes in a cohort with CDI that was not exposed to acid-suppressing agents.

RESULTS

Of 385 patients with CDI, 36.4% were undergoing acid suppression (23.4% with proton pump inhibitors, 13.5% with histamine type 2 blockers, and 0.5% with both). On univariate analysis, patients taking acid suppression medications were significantly older (69 vs 56 years; P<.001) and more likely to have severe (34.2% vs 23.6%; P=.03) or severe-complicated (4.4% vs 2.6% CDI; P=.006) infection than patients not undergoing acid suppression. On multivariable analyses, after adjustment for age and comorbid conditions, acid suppression medication use was not associated with severe or severe-complicated CDI. In addition, no association between acid suppression and treatment failure or CDI recurrence was found.

CONCLUSION

In this population-based study, after adjustment for age and comorbid conditions, patients with CDI who underwent acid suppression were not more likely to experience severe or severe-complicated CDI, treatment failure, or recurrent infection.

The Microbiome in Crohn's Disease: Role in Pathogenesis and Role of Microbiome Replacement Therapies

Individuals with a genetic predisposition to Crohn's disease develop aberrant immune responses to environmental triggers. The gastrointestinal microbiota is increasingly recognized to play an important role in the development of Crohn's disease. Decrease in global gut microbial diversity and specific bacterial alterations have been implicated in Crohn's disease. Advances in sequencing techniques and bioinformatics and correlation with host genetics continue to improve insight into the structure and function of the microbial community and interactions with the host immune system. This article summarizes the existing literature on the role of the gut microbiome and its manipulation in the development and management of Crohn's disease.

Microbiota Replacement Therapies: Innovation in Gastrointestinal Care

There has been an increasing interest in the association between human disease and altered gut microbiota, and therapeutics to modulate microbiota to treat disease. Healthy human gastrointestinal microbiota is highly diverse and rich, and harbors between 500 and 2,000 species. Diseases associated with dysbiotic microbiota include antibiotic-associated diarrhea, Clostridium difficile infection, multidrug-resistant organisms, inflammatory bowel disease, obesity, metabolic syndrome, diabetes mellitus, neuropsychiatric diseases, and systemic autoimmune diseases. Microbiota replacement therapies have shown immense promise in treatment of recurrent C. difficile infection and are being studied for other indications. Microbiota replacement therapies for indications other than C. difficile infection should be performed only in research settings. There is an immense need for standardized microbiota replacement therapies for C. difficile infection. Studies are needed to elucidate long-term safety and adverse events from these therapies.

RBX7455, a Non-frozen, Orally Administered Investigational Live Biotherapeutic, Is Safe, Effective, and Shifts Patients' Microbiomes in a Phase 1 Study for Recurrent Clostridioides difficile Infections

BACKGROUND

Recurrent Clostridioides difficile infections (rCDI) are a global public health threat. To reduce rCDI, microbiota-restoring therapies are needed, particularly standardized, easy-to-administer formulations.

METHODS

This phase I open-label trial assessed the safety, efficacy in preventing rCDI recurrence, and intestinal microbiome effects of RBX7455, a room temperature-stable, orally administered investigational live biotherapeutic. Adult participants with 1 or more prior episodes of rCDI received: 4 RBX7455 capsules twice daily for 4 days (group 1); 4 RBX7455 capsules twice daily for 2 days (group 2); or 2 RBX7455 capsules twice daily for 2 days (group 3). For all groups, the first dose was administered in clinic, with remaining doses self-administered at home. Adverse events were monitored during and for 6 months after treatment. Treatment success was defined as rCDI prevention through 8 weeks after treatment. Participants' microbiome composition was assessed prior to and for 6 months after treatment.

RESULTS

Nine of 10 group 1 patients (90%), 8 of 10 group 2 patients (80%), and 10 of 10 group 3 patients (100%) were recurrence-free at the 8-week endpoint with durability to 6 months. Seventy-five treatment-emergent adverse events were observed in 27 participants with no serious investigational product-related events. Prior to treatment, participants' microbiomes were dissimilar from the RBX7455 composition with decreased Bacteroidia- and Clostridia-class bacteria, whereas after treatment, responders' microbiomes showed increased Bacteroidia and Clostridia.

CONCLUSIONS

Three dosing regimens of RBX7455 were safe and effective at preventing rCDI. Responders' microbiomes converged toward the composition of RBX7455. These results support its continued clinical evaluation.

CLINICAL TRIALS REGISTRATION

NCT02981316.

Immunopathogenesis of juvenile dermatomyositis

There is increasing evidence for involvement of the mechanisms of the innate immune system in the pathogenesis of idiopathic inflammatory myopathies (IIMs), especially in the adult and juvenile forms of dermatomyositis. Juvenile dermatomyositis (JDM) is the most common form of childhood IIM, and this review focuses on recent advances in understanding the actions of the innate immune system in this condition. Over the last few years, great strides have been made in understanding immune dysregulation in IIM, including JDM. Novel autoantibodies have been identified, and new genetic contributions have been described. Among the most striking findings is type I interferon activity in JDM tissue and peripheral blood. This is in conjunction with the description of dysregulation of the major histocompatibility complex (MHC) class I gene and identification of plasmacytoid dendritic infiltrates as the possible cellular source of type I interferons. These findings also point toward the potential prognostic value of muscle biopsies and have helped expand our understanding of the etiopathogenesis of IIM.

Clostridium difficile infection: management strategies for a difficult disease

Clostridium difficile was first described as a cause of diarrhea in 1978 and in the last three decades has reached an epidemic state with increasing incidence and severity in both healthcare and community settings. There also has been a rise in severe outcomes from C. difficile infection (CDI). There have been tremendous advancements in the field of CDI with the identification of newer risk factors, recognition of CDI in populations previously thought not at risk and development of better diagnostic modalities. Several treatment options are available for CDI apart from metronidazole and vancomycin, and include new drugs such as fidaxomicin and other options such as fecal microbiota transplantation. This review discusses the epidemiology, risk factors and outcomes from CDI, and focuses primarily on existing and evolving treatment modalities.

SER-109: An Oral Investigational Microbiome Therapeutic for Patients with Recurrent Clostridioides difficile Infection (rCDI)

Clostridioides difficile infection (CDI) is classified as an urgent health threat by the Centers for Disease Control and Prevention (CDC), and affects nearly 500,000 Americans annually. Approximately 20−25% of patients with a primary infection experience a recurrence, and the risk of recurrence increases with subsequent episodes to greater than 40%. The leading risk factor for CDI is broad-spectrum antibiotics, which leads to a loss of microbial diversity and impaired colonization resistance. Current FDA-approved CDI treatment strategies target toxin or toxin-producing bacteria, but do not address microbiome disruption, which is key to the pathogenesis of recurrent CDI. Fecal microbiota transplantation (FMT) reduces the risk of recurrent CDI through the restoration of microbial diversity. However, FDA safety alerts describing hospitalizations and deaths related to pathogen transmission have raised safety concerns with the use of unregulated and unstandardized donor-derived products. SER-109 is an investigational oral microbiome therapeutic composed of purified spore-forming Firmicutes. SER-109 was superior to a placebo in reducing CDI recurrence at Week 8 (12% vs. 40%, respectively; p < 0.001) in adults with a history of recurrent CDI with a favorable observed safety profile. Here, we discuss the role of the microbiome in CDI pathogenesis and the clinical development of SER-109, including its rigorous manufacturing process, which mitigates the risk of pathogen transmission. Additionally, we discuss compositional and functional changes in the gastrointestinal microbiome in patients with recurrent CDI following treatment with SER-109 that are critical to a sustained clinical response.

Epidemiology, outcomes, and predictors of mortality in hospitalized adults with Clostridium difficile infection

Studies have demonstrated an increasing Clostridium difficile infection (CDI) incidence in hospitals and the community, with increasing morbidity and mortality. In this study, we analyzed data from the National Hospital Discharge Survey (NHDS) to evaluate CDI epidemiology, outcomes, and predictors of mortality in hospitalized adults. We identified cases of CDI (and associated comorbid conditions) from NHDS data from 2005 through 2009 using ICD-9 codes. Weighted univariate and multivariate analyses were performed to ascertain CDI incidence, associations between CDI and outcomes [length of stay (LOS), colectomy, all-cause in-hospital mortality, and discharge to a care facility], and predictors of all-cause in-hospital mortality. Of an estimated 162 million adult inpatients, 1.26 million (0.8 %) had CDI. The overall CDI incidence is 77.8/10,000 hospitalizations, with no statistically significant change over the study period. On multivariate analysis, after adjusting for age, gender, and comorbid conditions, CDI is an independent predictor of longer LOS (mean difference, 2.35 days), all-cause mortality [odds ratio (OR) 1.45], colectomy (OR 1.41), and discharge to a care facility (OR 2.12) (all P < 0.001). Elderly patients have a higher CDI incidence and worse outcomes than younger adults. The strongest predictors of all-cause mortality in patients with CDI include age 65 years or older, colectomy, and coagulation abnormalities. Despite stable CDI incidence and advances in management, CDI is associated with increased LOS, colectomy, all-cause in-hospital mortality, and discharge to a care facility in hospitalized, especially elderly, adults. Age older than 65 years should be added to the severity criteria for CDI.

Clinical implications of antibiotic impact on gastrointestinal microbiota and Clostridium difficile infection

The human gastrointestinal (GI) microbiota plays an important role in human health. Anaerobic bacteria prevalent in the normal colon suppress the growth of non-commensal microorganisms, thus maintaining colonic homeostasis. The GI microbiota is influenced by both patient-specific and environmental factors, particularly antibiotics. Antibiotics can alter the native GI microbiota composition, leading to decreased colonization resistance and opportunistic proliferation of non-native organisms. A common and potentially serious antibiotic-induced sequela associated with GI microbiota imbalance is Clostridium difficile infection (CDI), which may become recurrent if dysbiosis persists. This review focuses on the association between antibiotics and CDI, and the antibiotic-induced disruption leading to recurrent CDI. Promoting antibiotic stewardship is pivotal in protecting native microbiota and reducing the incidence of CDI and other GI infections.

Management of Clostridioides difficile infection in patients with inflammatory bowel disease

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

An evaluation of repeat stool testing for Clostridium difficile infection by polymerase chain reaction

GOALS

To evaluate the yield of repeat stool polymerase chain reaction (PCR) testing in patients with suspected Clostridium difficile infection (CDI).

BACKGROUND

CDI is a major challenge in health care due to its frequent occurrence and high associated costs. Enzyme immunoassay and PCR are commonly performed diagnostic tests for CDI.

METHODS

Our microbiology laboratory database was queried from January 1, 2008 to June 30, 2010 for all patients who underwent PCR stool testing for suspected CDI. Data collected included age, sex, number of stool tests performed within a 14-day period after the first test, and location of patient (inpatient vs. outpatient). Analyses were performed using JMP version 9.0.1.

RESULTS

PCR testing was performed in 15,515 patients. The median age was 58.3 years (range, 10 d to 104.3 y) and 46.2% of patients were women. Repeat testing was infrequent; 87.3% of patients had testing performed only once in a 14-day period. Increased age, male sex, and inpatient location were predictors of repeat testing. The median time between an initial test and the first repeat test was 5 days. After an initial negative test, the percentage of patients having a subsequent positive test was low (2.7% in 7 d and 3.2% in 14 d). The percentage of repeat tests that was positive within 7 days (2.9%) was lower than the percentage that was positive from day 8 to day 14 (4.8%, P=0.05).

CONCLUSIONS

Repeat testing for C. difficile has a low yield, and patients with an initial negative test should not routinely be retested.