Consequences of Clostridium difficile infection: understanding the healthcare burden

Multiplex polymerase chain reaction detection of enteropathogens in sewage in Norway

The primary objective of this small-scale study was to investigate the occurrence of enteropathogens in sewage (municipal wastewater) in Norway using the commercially available FilmArray^® multiplex polymerase chain reaction (PCR) system with the gastrointestinal (GI) panel. Our findings indicate that DNA/RNA of several enteropathogens are present simultaneously in Norwegian wastewater systems. The spectre was broad even in smaller communities. With some exceptions, occurrence corresponded more or less to the reported cases of infectious human gastrointestinal disease in the same geographical regions. The effects of different sewage purification techniques were assessed on a limited number of samples indicating that neither chemical nor biological treatment was sufficiently effective to reduce gene material from the pathogens to undetectable levels. Further studies are required to assess the performance and suitability FilmArray^® multiplex PCR when used on collective sewage samples in outbreak situations. Additionally, screening sewage samples using multiplex-PCR could be valuable in order to detect new and emerging pathogens and for preliminary analysis of samples before proceeding to more work demanding confirmatory techniques.

Impact of CodY protein on metabolism, sporulation and virulence in Clostridioides difficile ribotype 027

Toxin synthesis and endospore formation are two of the most critical factors that determine the outcome of infection by Clostridioides difficile. The two major toxins, TcdA and TcdB, are the principal factors causing damage to the host. Spores are the infectious form of C. difficile, permit survival of the bacterium during antibiotic treatment and are the predominant cell form that leads to recurrent infection. Toxin production and sporulation have their own specific mechanisms of regulation, but they share negative regulation by the global regulatory protein CodY. Determining the extent of such regulation and its detailed mechanism is important for understanding the linkage between two apparently independent biological phenomena and raises the possibility of creating new ways of limiting infection. The work described here shows that a codY null mutant of a hypervirulent (ribotype 027) strain is even more virulent than its parent in a mouse model of infection and that the mutant expresses most sporulation genes prematurely during exponential growth phase. Moreover, examining the expression patterns of mutants producing CodY proteins with different levels of residual activity revealed that expression of the toxin genes is dependent on total CodY inactivation, whereas most sporulation genes are turned on when CodY activity is only partially diminished. These results suggest that, in wild-type cells undergoing nutrient limitation, sporulation genes can be turned on before the toxin genes.

Impact of the Microbiome on the Immune System

Higher organisms are all born with general immunity as well as with, increasingly, more specific immune systems. All immune mechanisms function with the intent of aiding the body in defense against infection. Internal and external factors alike have varying effects on the immune system, and the immune response is tailored specifically to each one. Accompanying the components of the human innate and adaptive immune systems are the other intermingling systems of the human body. Increasing understanding of the body's immune interactions with other systems has opened new avenues of study, including that of the microbiome. The microbiome has become a highly active area of research over the last 10 to 20 years since the NIH began funding the Human Microbiome Project (HMP), which was established in 2007. Several publications have focused on the characterization, functions, and complex interplay of the microbiome as it relates to the rest of the body. A dysfunction between the microbiome and the host has been linked to various diseases including cancers, metabolic deficiencies, autoimmune disorders, and infectious diseases. Further understanding of the microbiome and its interaction with the host in relation to diseases is needed in order to understand the implications of microbiome dysfunction and the possible use of microbiota in the prevention of disease. In this review, we have summarized information on the immune system, the microbiome, the microbiome's interplay with other systems, and the association of the immune system and the microbiome in diseases such as diabetes and colorectal cancer.

Natural products show diverse mechanisms of action against Clostridium difficile

AIMS

To investigate the mechanisms of action of natural products with bactericidal (cinnamon root powder, peppermint oil, trans-cinnamaldehyde, menthol and zingerone) or bacteriostatic (fresh garlic bulb extract, garlic clove powder, Leptospermum honey and allicin) activity against two Clostridium difficile strains.

METHODS AND RESULTS

Bactericidal products significantly reduced intracellular ATP after 1 h (P ≤ 0·01), quantified using the BacTiter-Glo reagent, and damaged the cell membrane, shown by the leakage of both 260-nm-absorbing materials and protein, and the uptake of propidium iodide. Bacteriolysis was not observed, determined by measuring optical density of treated cell suspensions at 620-nm. The effect of three bacteriostatic products on protein synthesis was quantified using an Escherichia coli S30 extract system, with Leptospermum honey (16% w/v) showing significant inhibition (P < 0·01). Lastly, no products showed elevated minimum inhibitory concentrations against antimicrobial-resistant C. difficile, determined by broth microdilution.

CONCLUSIONS

Cytoplasmic membrane damage was identified as a mechanism of action that may contribute to the activity of several natural products against C. difficile.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study describes the possible mechanisms of action of natural products against C. difficile, yet the efficacy in vivo to be determined.

Pharmacokinetics and safety of fidaxomicin in patients with inflammatory bowel disease and Clostridium difficile infection: an open-label Phase IIIb/IV study (PROFILE)

OBJECTIVES

Inflammatory bowel disease (IBD) poses an increased risk for Clostridium difficile infection (CDI). Fidaxomicin has demonstrated non-inferiority to vancomycin for initial clinical cure of CDI in patients without IBD; however, lack of data has caused concerns regarding potential systemic absorption of fidaxomicin in patients with IBD.

METHODS

The plasma pharmacokinetics (PK) of fidaxomicin and its primary metabolite OP-1118 were evaluated in a multicentre, open-label, single-arm, Phase IIIb/IV study enrolling patients with active IBD and CDI. Patients received fidaxomicin, 200 mg twice daily for 10 days. The primary and secondary endpoints were, respectively, plasma and stool PK of fidaxomicin and OP-1118 on Days 1, 5 and 10 of treatment. Other secondary endpoints included safety of fidaxomicin treatment (assessed until Day 180). ClinicalTrials.gov identifier: NCT02437591.

RESULTS

Median Tmax of fidaxomicin and OP-1118 for the PK analysis set (PKAS; 24 patients) was 1-2 h across Days 1, 5 and 10. Cmax ranges were 1.2-154 ng/mL for fidaxomicin and 4.7-555 ng/mL for OP-1118 across Days 1, 5 and 10 (PKAS). The ranges of concentrations in stool were 17.8-2170 μg/g for fidaxomicin and 0-1940 μg/g for OP-1118. Sixty percent (15/25) of patients experienced treatment-emergent adverse events (TEAEs), none of which led to treatment discontinuation or death.

CONCLUSIONS

Maximum fidaxomicin and OP-1118 plasma concentrations observed in this study population suggest no increase in absorption, compared with patients without IBD. Incidence of TEAEs was similar to previous Phase III trials, suggesting that fidaxomicin is comparatively well tolerated in patients with IBD.

Cost-Effectiveness Analysis of Bezlotoxumab Added to Standard of Care Versus Standard of Care Alone for the Prevention of Recurrent Clostridium difficile Infection in High-Risk Patients in Spain

INTRODUCTION

Clostridium difficile infection (CDI) is the major cause of infectious nosocomial diarrhoea and is associated with considerable morbidity, mortality and economic impact. Bezlotoxumab administered in combination with standard of care (SoC) antibiotic therapy prevents recurrent CDI. This study assessed the cost-effectiveness of bezlotoxumab added to SoC, compared to SoC alone, to prevent the recurrence of CDI in high-risk patients from the Spanish National Health System perspective.

METHODS

A Markov model was used to simulate the natural history of CDI over a lifetime horizon in five populations of patients at high risk of CDI recurrence according to MODIFY trials: (1) ≥ 65 years old; (2) severe CDI; (3) immunocompromised; (4) ≥ 1 CDI episode in the previous 6 months; and (5) ≥ 65 years old and with ≥ 1 CDI episode in the previous 6 months. The incremental cost-effectiveness ratio (ICER) expressed as cost per quality-adjusted life-year (QALY) gained was calculated. Deterministic (DSA) and probabilistic sensitivity analyses (PSA) were performed.

RESULTS

In all patient populations (from 1 to 5), bezlotoxumab added to SoC reduced CDI recurrence compared to SoC alone by 26.4, 19.5, 21.2, 26.6 and 39.7%, respectively. The resulting ICERs for the respective subgroups were €12,724, €17,495, €9545, €7386, and €4378. The model parameters with highest impact on the ICER were recurrence rate (first), mortality, and utility values. The probability that bezlotoxumab was cost-effective at a willingness-to-pay threshold of €21,000/QALY was 85.5%, 54.1%, 86.0%, 94.5%, 99.6%, respectively.

CONCLUSION

The results suggest that bezlotoxumab added to SoC compared to SoC alone is a cost-effective treatment to prevent the recurrence of CDI in high-risk patients. The influence of changes in model parameters on DSA results was higher in patients  ≥ 65 years old, with severe CDI and immunocompromised. Additionally, PSA estimated that the probability of cost-effectiveness exceeded 85% in most subgroups.

FUNDING

Merck Sharp & Dohme Corp.

Healthcare burden of recurrent Clostridioides difficile infection in Japan: A retrospective database study

This retrospective database study aimed to assess the healthcare burden of hospitalization cost and duration associated with recurrent Clostridioides difficile infection (rCDI) by comparison with C. difficile infection (CDI) in Japan, using a health claims database of 270 acute care hospitals. Overall, 5423 hospitalized patients, with a record of one hospital-onset, healthcare facility-associated primary CDI episode within the 180-day period, from its onset between January 2012 and September 2016, were included. Of these, 353 had at least one rCDI and 5070 had no rCDI. Compared with those with no rCDI, the median total cost of hospitalization for patients with rCDI was JPY 1,184,371 (USD 11,691) higher (JPY 2,489,424 [interquartile range {IQR}: 1,597,424-4,008,751] compared with JPY 1,305,053 [624,033-2,549,569]). In addition, rCDI resulted in twice longer hospitalization duration in median compared with CDI (79 days [IQR: 53-117] compared with 40 days [20-74]). Based on a generalized linear regression model with a Gamma distribution and a logarithmic link function, the estimated mean of cost and duration of hospitalization for patients with rCDI were JPY 1,284,519 (95% confidence limit: -95,532-2,664,569) (USD 12,679) higher and 20.3 days (-9.5‒50.0) longer, compared with patients with no rCDI. The estimated mean difference in cost was higher in older patients and patients with diseases resulting in an immunosuppressive state. Higher costs and longer hospitalization for rCDI impose a great burden on healthcare system as well as patients, highlighting the importance of preventing recurrence of CDI.

The Pharmacoeconomic Aspects of Antibiotic Stewardship Programs

Optimal antimicrobial therapy must take into account the key factors in antibiotic selection, that is, spectrum, tissue penetration, resistance potential, safety profile, and relative cost-effectiveness. The least expensive drug is usually accompanied by other concerns, such as high resistance potential, poor side effect profile, pharmacokinetic properties that limit penetration into target tissue (site of infection), and/or suboptimal activity against the presumed/known pathogen. It is false economy to preferentially select the least expensive antibiotics solely because of its acquisition cost. Therapeutic failure and hidden costs may make an apparently less expensive antibiotic most costly in the end.

Changes in microbiota composition, bile and fatty acid metabolism, in successful faecal microbiota transplantation for Clostridioides difficile infection

Background

Alteration of the gut microbiota by repeated antibiotic treatment increases susceptibility to Clostridioides difficile infection. Faecal microbiota transplantation from donors with a normal microbiota effectively treats C. difficile infection.

Methods

The study involved 10 patients with recurrent C. difficile infection, nine of whom received transplants from individual donors and one who received a donor unit from a stool bank (OpenBiome).

Results

All individuals demonstrated enduring post-transplant resolution of C. difficile- associated diarrhoea. Faecal microbiota diversity of recipients significantly increased, and the composition of the microbiota resembled that of the donor. Patients with C. difficile infection exhibited significantly lower faecal levels of secondary/ bile acids and higher levels of primary bile acids. Levels of secondary bile acids were restored in all transplant recipients, but to a lower degree with the OpenBiome transplant. The abundance increased of bacterial genera known from previous studies to confer resistance to growth and germination of C. difficile. These were significantly negatively associated with primary bile acid levels and positively related with secondary bile acid levels. Although reduced levels of the short chain fatty acids, butyrate, propionate and acetate, have been previously reported, here we report elevations in SCFA, pyruvic and lactic fatty acids, saturated, ω-6, monounsaturated, ω-3 and ω-6 polyunsaturated fatty acids (PUFA) in C. difficile infection. This potentially indicates one or a combination of increased dietary FA intake, microbial modification of FAs or epithelial cell damage and inflammatory cell recruitment. No reversion to donor FA profile occurred post-FMT but ω-3 to ω-6 PUFA ratios were altered in the direction of the donor. Archaeal metabolism genes were found in some samples post FMT.

Conclusion

A consistent metabolic signature was identified in the post-transplant microbiota, with reduced primary bile acids and substantial restoration of secondary bile acid production capacity. Total FA levels were unchanged but the ratio of inflammatory to non-inflammatory FAs decreased.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0860-5) contains supplementary material, which is available to authorized users.

Fidaxomicin for the treatment of Clostridium difficile infection (CDI) in at-risk patients with inflammatory bowel disease, fulminant CDI, renal impairment or hepatic impairment: a retrospective study of routine clinical use (ANEMONE)

Information is limited or lacking on fidaxomicin treatment of Clostridium difficile infection (CDI) in patients with inflammatory bowel disease, fulminant or life-threatening CDI, severe renal impairment, moderate-to-severe hepatic impairment and pregnancy. The ANEMONE study investigated fidaxomicin use in a routine clinical setting, focusing on these medical conditions of specific interest (MCSIs). This retrospective, post-authorisation study reviewed hospital records from Austria, Germany, Spain and the UK (June 2012–June 2015), collecting data from hospital admission to 30 days after last fidaxomicin dose. The primary objective was to identify the proportion of fidaxomicin-treated patients with MCSIs. Secondary objectives were to describe 30-day mortality, changes in ECG and laboratory parameters, fidaxomicin exposure and CDI response (resolution of diarrhoea; 30-day recurrence). 45.3% (261/576) of patients had ≥ 1 MCSI. Thirty-day mortality (post-first dose) was 17.0% (98/576) in the total population and slightly higher (24.6–27.6%) in patients with fulminant CDI or severe renal impairment. 29.6% (24/81) deaths of known cause were attributable to CDI. Of changes in laboratory parameters or ECG findings, only a decrease in leucocyte counts appeared associated with fidaxomicin, consistent with a positive treatment response. Diarrhoea resolved in 78.0% (404/518) of treatment episodes; diarrhoea resolution was lowest in patients with fulminant CDI (investigator-defined, 67.5%, 56/88) and severe renal impairment (68.0%, 68/100). Thirty-day recurrence (18.8%, 79/420) was similar across MCSI subgroups. Although almost half of fidaxomicin-treated patients had ≥ 1 MCSI, the majority of patients in all subgroups had positive responses to treatment, and no particular safety concerns were identified.

Clostridium difficile exosporium cysteine-rich proteins are essential for the morphogenesis of the exosporium layer, spore resistance, and affect C. difficile pathogenesis

Clostridium difficile is a Gram-positive spore-former bacterium and the leading cause of nosocomial antibiotic-associated diarrhea that can culminate in fatal colitis. During the infection, C. difficile produces metabolically dormant spores, which persist in the host and can cause recurrence of the infection. The surface of C. difficile spores seems to be the key in spore-host interactions and persistence. The proteome of the outermost exosporium layer of C. difficile spores has been determined, identifying two cysteine-rich exosporium proteins, CdeC and CdeM. In this work, we explore the contribution of both cysteine-rich proteins in exosporium integrity, spore biology and pathogenesis. Using targeted mutagenesis coupled with transmission electron microscopy we demonstrate that both cysteine rich proteins, CdeC and CdeM, are morphogenetic factors of the exosporium layer of C. difficile spores. Notably, cdeC, but not cdeM spores, exhibited defective spore coat, and were more sensitive to ethanol, heat and phagocytic cells. In a healthy colonic mucosa (mouse ileal loop assay), cdeC and cdeM spore adherence was lower than that of wild-type spores; while in a mouse model of recurrence of the disease, cdeC mutant exhibited an increased infection and persistence during recurrence. In a competitive infection mouse model, cdeC mutant had increased fitness over wild-type. Through complementation analysis with FLAG fusion of known exosporium and coat proteins, we demonstrate that CdeC and CdeM are required for the recruitment of several exosporium proteins to the surface of C. difficile spores. CdeC appears to be conserved exclusively in related Peptostreptococcaeace family members, while CdeM is unique to C. difficile. Our results sheds light on how CdeC and CdeM affect the biology of C. difficile spores and the assembly of the exosporium layer and, demonstrate that CdeC affect C. difficile pathogenesis.

We discovered a mechanism of assembly of the outer most layer of Clostridium difficile spores, the exosporium. While CdeC is conserved in several Peptostreptococcaeace family members, CdeM is unique to C. difficile. We show that two proteins that are rich in cysteine amino acid residues, CdeC and CdeM, are essential for the recruitment of additional spore coat and exosporium proteins. The absence of CdeC, had profound implications in the correct spore coat assembly which were related to decreased spore resistant properties that are relevant for in vivo infection such as lysozyme resistance, macrophage infection. Notably, the absence of either cysteine rich proteins leads to a decrease in spore adherence of C. difficile spores to healthy colonic mucosa; but only the absence of CdeC affected in vivo competitive fitness in a mouse model, recurrence of the disease in a mouse model of recurrent infection. Considering the importance of the outer layers of C. difficile spores in spore-host interactions, our findings have broad implications on the biology of C. difficile spores and to C. difficile pathogenesis.

Encapsulation of Biological Agents in Hydrogels for Therapeutic Applications

Hydrogels are materials specially suited for encapsulation of biological elements. Their large water content provides an environment compatible with most biological molecules. Their crosslinked nature also provides an ideal material for the protection of encapsulated biological elements against degradation and/or immune recognition. This makes them attractive not only for controlled drug delivery of proteins, but they can also be used to encapsulate cells that can have therapeutic applications. Thus, hydrogels can be used to create systems that will deliver required therapies in a controlled manner by either encapsulation of proteins or even cells that produce molecules that will be released from these systems. Here, an overview of hydrogel encapsulation strategies of biological elements ranging from molecules to cells is discussed, with special emphasis on therapeutic applications.

Cost-effectiveness of three different strategies for the treatment of first recurrent Clostridium difficile infection diagnosed in a community setting

OBJECTIVE

A significant portion of patients with Clostridium difficile infections (CDI) experience recurrence, and there is little consensus on its treatment. With the availability of newer agents for CDI and the added burdens of recurrent disease, a cost-effectiveness analysis may provide insight on the most efficient use of resources.

DESIGN

A decision-tree analysis was created to compare the cost-effectiveness of 3 possible treatments for patients with first CDI recurrence: oral vancomycin, fidaxomicin, or bezlotoxumab plus vancomycin. The model was performed from a payer's perspective with direct cost inputs and a timeline of 1 year. A systematic review of literature was performed to identify clinical, utility, and cost data. Quality-adjusted life years (QALY) and incremental cost-effectiveness ratios were calculated. The willingness-to-pay (WTP) threshold was set at $100,000 per QALY gained. The robustness of the model was tested using one-way sensitivity analyses and probabilistic sensitivity analysis.

RESULTS

Vancomycin had the lowest cost ($15,692) and was associated with a QALY gain of 0.8019 years. Bezlotoxumab plus vancomycin was a dominated strategy. Fidaxomicin led to a higher QALY compared to vancomycin, at an incremental cost of $500,975 per QALY gained. Based on our WTP threshold, vancomycin alone was the most cost-effective regimen for treating the first recurrence of CDI. Sensitivity analyses demonstrated the model's robustness.

CONCLUSIONS

Vancomycin alone appears to be the most cost-effective regimen for the treatment of first recurrence of CDI. Fidaxomicin alone led to the highest QALY gained, but at a cost beyond what is considered cost-effective.

The Differential Diagnosis of Acute Colitis: Clues to a Specific Diagnosis

This review describes a systematic approach to the interpretation of colonic biopsy specimens of patients with acute colitis. Five main histologic patterns are discussed: acute colitis, focal active colitis, pseudomembranous colitis, hemorrhagic colitis, and ischemic colitis. For each pattern, the most common etiologic associations and their differential diagnoses are presented. Strategies based on histologic analysis and clinical considerations to differentiate acute from chronic colitides are discussed.

Economic Burden of Clostridium difficile Infection in European Countries

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

Cost-effectiveness analysis of oral probiotics for the prevention of Clostridium difficile-associated diarrhoea in children and adolescents

BACKGROUND

The incidence of Clostridium difficile-associated diarrhoea (CDAD) in hospitalized children and adolescents has been increasing year-on-year. Paediatric CDAD places a significant economic burden on healthcare systems. Probiotics are live organisms thought to improve the microbial balance of the host, counteract disturbances in intestinal flora, and reduce the risk of colonization by pathogenic bacteria.

AIM

A cost-effectiveness analysis was conducted to assess the economy of probiotics for the prevention of CDAD in children and adolescents receiving antibiotics.

METHODS

A decision tree model combining clinical effectiveness, utility and cost data was used. Sensitivity analyses were conducted to determine the robustness of the model outcomes.

FINDING

The 'oral probiotics' strategy and 'no probiotics' strategy offered patients 0.05876 and 0.056 quality-adjusted life years (QALYs) at a cost of $16,668.70 and $20,355.28, respectively. The oral probiotics strategy exhibited higher QALY and lower cost, and represents the cost-saving strategy. The results were robust for sensitivity analyses.

CONCLUSION

From the perspective of the medical system, oral probiotics as a preventive strategy for CDAD in hospitalized children and adolescents receiving a therapeutic course of antibiotics reduced the risk of CDAD and represents a cost-saving strategy.

The effect of concomitant use of systemic antibiotics in patients with Clostridium difficile infection receiving metronidazole therapy

Management of Clostridium difficile infection (CDI) involves discontinuation of the offending antibiotic agent as soon as possible. However, the ongoing infection does not allow discontinuation of the offending antibiotic. We aimed to retrospectively investigate the predictors of treatment failure and impact of the concomitant use of systemic antibiotics in patients receiving metronidazole therapy. This study was conducted among patients hospitalised at a second care academic hospital from January 2013 to December 2014. Eligible patients were identified by reviewing stool toxin enzyme immunoassay results for C. difficile. Diarrhoea was defined as the passage of at least three loose or watery stools within 24 h. Among 314 patients with CDI receiving metronidazole therapy, 62 (19.7%) showed treatment failure and 105 (33.4%) received concomitant antibiotics. Underlying dialysis, fever >38.3 °C, low median serum albumin levels and concomitant use of antibiotics were independent predictors of treatment failure in patients with CDI receiving metronidazole therapy. The concomitant use of antibiotics increased the rates of treatment failure and 30-day mortality in patients receiving metronidazole therapy. These results suggest that metronidazole should be used in mild cases of CDI only after discontinuation of the offending antibiotics.

Fecal microbiota transplantation and its potential therapeutic uses in gastrointestinal disorders

Typical human gut flora has been well characterized in previous studies and has been noted to have significant differences when compared with the typical microbiome of various disease states involving the gastrointestinal tract. Such diseases include Clostridium difficile colitis, inflammatory bowel disease, functional bowel syndromes, and various states of liver disease. A growing number of studies have investigated the use of a fecal microbiota transplant as a potential therapy for these disease states.

Outcomes With Fidaxomicin Therapy in Clostridium difficile Infection

BACKGROUND AND GOALS

Fidaxomicin is a new antibiotic used to treat Clostridium difficile infection (CDI). Given limited clinical experience with fidaxomicin, we assessed outcomes in a diverse cohort of patients with CDI treated with fidaxomicin.

STUDY

All CDI cases treated with fidaxomicin at 3 referral centers over a 4-year period were included. Response was defined as resolution of diarrhea and recurrence was defined by recurrence of CDI within 8 weeks of the end of treatment.

RESULTS

Overall, 81 patients (median age 55.9 y; 53% female; 26% with inflammatory bowel disease) were included. Response occurred in 90%. Responders had fewer prior CDI episodes [median 1 (range, 0 to 8)] than nonresponders [median 2.5 (range, 1 to 8)], P=0.01. Response after a first CDI episode was 100%, 96% after 1 prior episode, and 82% after 2 or more, P=0.02. Recurrence occurred in 19%. Patients without recurrence had fewer prior episodes of CDI [median 1 (range, 0 to 6)] than patients who recurred [median 2 (range, 1 to 8)], P=0.005. Recurrence after a first episode was 0%, 23% after 1 prior episode, and 29% after 2 or more, P=0.005. All patients with inflammatory bowel disease responded either with improvement of symptoms or a negative C. difficile test; 19% recurred.

CONCLUSIONS

All patients with a first CDI episode treated with fidaxomicin responded with no recurrences. Patients with prior CDI episodes were less likely to respond (especially with more than 1 prior episode) and more likely to recur, suggesting a greater clinical benefit of fidaxomicin earlier in the course of CDI.

Economic burden and cost-effective management of Clostridium difficile infections

Clostridium difficile infection (CDI) is the most important cause of healthcare-associated infectious diarrhea in industrialized countries. We performed a literature review of the overall economic burden of initial and recurrent CDI as well as of the cost-effectiveness of the various treatment strategies applied in these settings. Even though analysis of health economic data is complicated by the limited comparability of results, our review identified several internationally consistent results. Authors from different countries have shown that recurrent CDI disproportionally contributes to the overall economic burden of CDI and therefore offers considerable saving potential. Subsequent cost-effectiveness analyses almost exclusively identified fidaxomicin as the preferred treatment option for initial CDI and fecal microbiota transplant (FMT) for recurrent CDI. Among the various FMT protocols, optimum results were obtained using early colonoscopy-based FMT.

Barriers and facilitators to Clostridium difficile infection prevention: A nursing perspective

BACKGROUND

Clostridium difficile infection (CDI) is a critical patient safety issue. Consistent and regular performance of appropriate practices is effective in preventing CDI. Variation in adherence to these practices can impede their effective implementation and weaken CDI prevention.

METHODS

Using the Systems Engineering Initiative for Patient Safety (SEIPS) framework we convened a focus group of 10 nurses to identify barriers and facilitators to compliance with a CDI prevention bundle that includes (1) prompt diagnostic testing, (2) empirical isolation for patients with suspected CDI, (3) consistent and appropriate contact isolation, (4) hand hygiene, and (5) disinfection of the patient room and objects in the room. On completion of transcript coding, analyses were performed based on bundle intervention and the work system element of the SEIPS model.

RESULTS

A total of 58 excerpts were coded. Work system barriers or facilitators were associated with nearly every bundle intervention. The work system elements raised in over half of the excerpts were task (n = 31) (eg, amount of additional effort required to don and doff gloves and gowns) and organization (n = 30) (eg, recognition by all staff of the severity of CDI). Contact isolation was the most frequently discussed bundle intervention (n = 24).

CONCLUSIONS

The SEIPS systems engineering framework is useful to evaluate infection prevention practices for CDI and identify opportunities for improvement. Addressing the work system barriers and facilitators identified in this study is essential to effective implementation of infection prevention interventions, specifically for CDI.

Faecal microbiota transplantation: a regulatory hurdle?

During faecal microbiota transplantation, stool from a healthy donor is transplanted to treat a variety of dysbiosis-associated gut diseases. Competent authorities are faced with the challenge to provide adequate regulation. Currently, regulatory harmonization is completely lacking and authorities apply non-existing to most stringent requirements. A regulatory approach for faecal microbiota transplantation could be inserting faecal microbiota transplantation in the gene-, cell- and tissue regulations, including the hospital exemption system in the European Advanced Therapy Medicinal Products regulation, providing a pragmatic and efficacy-risk balanced approach and granting all patients as a matter of principle access to this therapy.

Sanitary Sewer Overflows and Emergency Room Visits for Gastrointestinal Illness: Analysis of Massachusetts Data, 2006-2007

BACKGROUND

Sanitary sewer overflows (SSOs) occur when untreated sewage is discharged into water sources before reaching the treatment facility, potentially contaminating the water source with gastrointestinal pathogens.

OBJECTIVES

The objective of this paper is to assess associations between SSO events and rates of gastrointestinal (GI) illness in Massachusetts.

METHODS

A case-crossover study design was used to investigate association between SSO events and emergency room (ER) visits with a primary diagnosis of gastrointestinal (GI) illness in Massachusetts for 2006-2007. ER visits for GI were considered exposed if an SSO event occurred in the county of residence within three hazard periods, 0-4 d, 5-9 d, or 10-14 d, before the visit. A time-stratified bidirectional design was used to select control days for each ER visit on the same day of the week during the same month. Fixed effect logistic regression models were used to estimate the risk of ER visits following the SSO event.

RESULTS

During the study period, there were 270 SSO events for northeastern Massachusetts and 66,460 ER admissions with GI illness listed as the primary diagnostic code. The overall odds ratio (OR) for ER visits for GI illness was 1.09 [95% confidence interval (CI): 1.03, 1.16] in the 10-14 d period following an SSO event, with positive ORs for all age groups and for three of the four counties. The 0-4 d and 5-9 d periods following an SSO event were not associated with ER visits for GI illness overall, and associations by county or age were inconsistent.

CONCLUSIONS

We demonstrated an association between SSO events and ER visits for GI illness using a case-crossover study design. In light of the aging water infrastructure in the United States and the expected increase in heavy rainfall events, our findings suggest a potential health impact associated with sewage overflows. https://doi.org/10.1289/EHP2048.

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

BACKGROUND AND OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

OTHER

This analysis was initiated and funded by Astellas Pharma Inc.

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.

Microencapsulation of Clostridium difficile specific bacteriophages using microfluidic glass capillary devices for colon delivery using pH triggered release

The prevalence of pathogenic bacteria acquiring multidrug antibiotic resistance is a global health threat to mankind. This has motivated a renewed interest in developing alternatives to conventional antibiotics including bacteriophages (viruses) as therapeutic agents. The bacterium Clostridium difficile causes colon infection and is particularly difficult to treat with existing antibiotics; phage therapy may offer a viable alternative. The punitive environment within the gastrointestinal tract can inactivate orally delivered phages. C. difficile specific bacteriophage, myovirus CDKM9 was encapsulated in a pH responsive polymer (Eudragit® S100 with and without alginate) using a flow focussing glass microcapillary device. Highly monodispersed core-shell microparticles containing phages trapped within the particle core were produced by in situ polymer curing using 4-aminobenzoic acid dissolved in the oil phase. The size of the generated microparticles could be precisely controlled in the range 80 μm to 160 μm through design of the microfluidic device geometry and by varying flow rates of the dispersed and continuous phase. In contrast to free 'naked' phages, those encapsulated within the microparticles could withstand a 3 h exposure to simulated gastric fluid at pH 2 and then underwent a subsequent pH triggered burst release at pH 7. The significance of our research is in demonstrating that C. difficile specific phage can be formulated and encapsulated in highly uniform pH responsive microparticles using a microfluidic system. The microparticles were shown to afford significant protection to the encapsulated phage upon prolonged exposure to an acid solution mimicking the human stomach environment. Phage encapsulation and subsequent release kinetics revealed that the microparticles prepared using Eudragit® S100 formulations possess pH responsive characteristics with phage release triggered in an intestinal pH range suitable for therapeutic purposes. The results reported here provide proof-of-concept data supporting the suitability of our approach for colon targeted delivery of phages for therapeutic purposes.

Prediction of Recurrent Clostridium Difficile Infection Using Comprehensive Electronic Medical Records in an Integrated Healthcare Delivery System

BACKGROUND Predicting recurrent Clostridium difficile infection (rCDI) remains difficult.

METHODS

We employed a retrospective cohort design. Granular electronic medical record (EMR) data had been collected from patients hospitalized at 21 Kaiser Permanente Northern California hospitals. The derivation dataset (2007-2013) included data from 9,386 patients who experienced incident CDI (iCDI) and 1,311 who experienced their first CDI recurrences (rCDI). The validation dataset (2014) included data from 1,865 patients who experienced incident CDI and 144 who experienced rCDI. Using multiple techniques, including machine learning, we evaluated more than 150 potential predictors. Our final analyses evaluated 3 models with varying degrees of complexity and 1 previously published model. RESULTS Despite having a large multicenter cohort and access to granular EMR data (eg, vital signs, and laboratory test results), none of the models discriminated well (c statistics, 0.591-0.605), had good calibration, or had good explanatory power. CONCLUSIONS Our ability to predict rCDI remains limited. Given currently available EMR technology, improvements in prediction will require incorporating new variables because currently available data elements lack adequate explanatory power. Infect Control Hosp Epidemiol 2017;38:1196-1203.

Rethinking Strategies to Select Antibiotic Therapy in Clostridium difficile infection

In recent years, Clostridium difficile infection (CDI) has become a global public health threat associated with increased morbidity, mortality, and economic burden, all of which are exacerbated with disease recurrence. Current guidelines informing treatment decisions are largely based on definitions of disease severity at diagnosis, with subjective components not well delineated across treatment algorithms and clinical trials. Furthermore, there is little evidence linking severity at onset to outcome. However, reducing the risk of recurrence may offer both a better outcome for the individual and decreased downstream economic impact. The authors present data supporting the opinion that patients deemed at low risk for recurrence should receive vancomycin (or metronidazole when cost is an issue), while those at higher risk of recurrence would benefit from fidaxomicin treatment. Although further prospective studies are needed, choosing treatment with the goal of preventing recurrent CDI may offer a better guide than disease severity.

Cost-effectiveness analysis on the use of fidaxomicin and vancomycin to treat Clostridium difficile infection in France

BACKGROUND

Fidaxomicin is a macrocyclic antibiotic with proven efficacy against Clostridium difficile infection (CDI) in adults. It was licensed in France in 2012, but, due to higher acquisition costs compared with existing treatments, healthcare providers require information on its cost/benefit profile.

OBJECTIVE

To compare healthcare costs and health outcomes of fidaxomicin and vancomycin, as reference treatment for CDI.

METHODS

A Markov model was used to simulate the treatment pathway, over 1 year, of adult patients with CDI receiving fidaxomicin or vancomycin. Several patient sub-groups (severe CDI; recurrent CDI; concomitant antibiotics; cancer; renal failure; elderly) were evaluated. Cost-effectiveness was analyzed based on cure and recurrence rates derived from published randomized clinical trials comparing fidaxomicin and vancomycin, and costs calculated from the payer perspective using French hospitalization data and drug cost databases. Model outputs included costs in euros (reference year 2014) and health outcomes (recurrence; sustained cure rates). Alternative scenario and sensitivity analyses were performed using data from other clinical trials in CDI, including one conducted in real-life clinical practice in France.

RESULTS

Drug acquisition costs were €1,692 higher in fidaxomicin-treated patients, but this was offset by the lower hospitalization costs with fidaxomicin, which were reduced by €1,722. The reduction in the cost of hospitalization was driven by the significantly lower number of recurrences in fidaxomicin-treated patients, offsetting the acquisition cost of fidaxomicin in all sub-groups except recurrent CDI and concomitant antibiotics.

CONCLUSION

This study demonstrated that, despite higher acquisition costs, the lower recurrence rate with fidaxomicin resulted in cost savings or low incremental costs compared with vancomycin.

Pharmacokinetics of surotomycin from phase 1 single and multiple ascending dose studies in healthy volunteers

Background

Surotomycin, a novel, orally administered, cyclic, lipopeptide antibacterial in development for the treatment of Clostridium difficile-associated diarrhea, has demonstrated minimal intestinal absorption in animal models.

Methods

Safety, tolerability, and plasma pharmacokinetics of single and multiple ascending oral doses (SAD/MAD) of surotomycin in healthy volunteers were characterized in two randomized, double-blind, placebo-controlled, phase 1 studies.

Results

Participants were sequentially enrolled into one of four SAD (500, 1000, 2000, 4000 mg surotomycin) or three MAD (250, 500, 1000 mg surotomycin twice/day for 14 days) cohorts. Ten subjects were randomized 4:1 into each cohort to receive surotomycin or placebo. Surotomycin plasma concentrations rose as dose increased (maximum plasma concentration [C_max]: 10.5, 21.5, 66.6, and 86.7 ng/mL). Systemic levels were generally low, with peak median surotomycin plasma concentrations observed 6–12 h after the first dose. In the MAD study, surotomycin plasma concentrations were higher on day 14 (C_max: 25.5, 37.6, and 93.5 ng/mL) than on day 1 (C_max: 6.8, 11.0, and 21.1 ng/mL for increasing doses), indicating accumulation. In the SAD study, <0.01% of the administered dose was recovered in urine. Mean surotomycin stool concentration from the 1000 mg MAD cohort was 6394 μg/g on day 5. Both cohorts were well tolerated with all adverse events reported as mild to moderate.

Conclusion

Both SAD and MAD studies of surotomycin demonstrated minimal systemic exposure, with feces the primary route of elimination following oral administration; consistent with observations with similar compounds, such as fidaxomicin. Results of these phase 1 studies support the continued clinical development of surotomycin for the treatment of Clostridium difficile-associated diarrhea.

Trial registration

NCT02835118 and NCT02835105. Retrospectively registered, July 13 2016.

Current knowledge on the laboratory diagnosis of Clostridium difficile infection

Clostridium difficile (C. difficile) is a spore-forming, toxin-producing, gram-positive anaerobic bacterium that is the principal etiologic agent of antibiotic-associated diarrhea. Infection with C. difficile (CDI) is characterized by diarrhea in clinical syndromes that vary from self-limited to mild or severe. Since its initial recognition as the causative agent of pseudomembranous colitis, C. difficile has spread around the world. CDI is one of the most common healthcare-associated infections and a significant cause of morbidity and mortality among older adult hospitalized patients. Due to extensive antibiotic usage, the number of CDIs has increased. Diagnosis of CDI is often difficult and has a substantial impact on the management of patients with the disease, mainly with regards to antibiotic management. The diagnosis of CDI is primarily based on the clinical signs and symptoms and is only confirmed by laboratory testing. Despite the high burden of CDI and the increasing interest in the disease, episodes of CDI are often misdiagnosed. The reasons for misdiagnosis are the lack of clinical suspicion or the use of inappropriate tests. The proper diagnosis of CDI reduces transmission, prevents inadequate or unnecessary treatments, and assures best antibiotic treatment. We review the options for the laboratory diagnosis of CDI within the settings of the most accepted guidelines for CDI diagnosis, treatment, and prevention of CDI.

The risk of Clostridium difficile infection in patients with pernicious anaemia: a retrospective cohort study using primary care database

Background

Studies have found an association between proton pump inhibitor (PPI) use and Clostridium difficile infection. The purpose of this study was to determine whether the mechanism by which PPIs induce an increased risk of C. difficile infection is supported by the same mechanism acting in another cause of achlorhydria, pernicious anaemia.

Methods

Using a database of anonymised primary care records between 1990 and 2013, we selected exposed patients with a diagnosis of pernicious anaemia treated with vitamin B12 therapy. Each exposed patient was matched by age, gender and general practice to up to 10 controls. Cox regression analysis was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for C. difficile infection with pernicious anaemia, adjusted for potential confounders.

Results

We identified 45,467 exposed patients matched to 449,635 controls. The crude incidence rate of C. difficile infection was 1.85/1000 person-years for the exposed cohort and 1.09/1000 person-years for controls. Patients with pernicious anaemia had a greater risk of C. difficile infection than the controls (adjusted HR 1.57, 95% CI 1.40-1.76).

Conclusions

Pernicious anaemia patients have an increased risk of C. difficile infection. This supports the theory that severe achlorhydria is the mechanism that increases the risk of C. difficile infection in long-term PPI users.

Lack of adherence to SHEA-IDSA treatment guidelines for Clostridium difficile infection is associated with increased mortality

OBJECTIVES

The objective of this study was to determine our institution's compliance with 2010 Society for Healthcare Epidemiology of America and IDSA Clostridium difficile infection (CDI) treatment guidelines and their respective outcomes.

METHODS

We collected clinical parameters, laboratory values, antibiotic therapy and clinical outcomes from the electronic medical records for all patients hospitalized at our institution with a diagnosis of CDI from December 2012 to November 2013. We specifically evaluated whether SHEA-IDSA treatment guidelines were followed and evaluated the associations between guideline adherence and severe outcomes including mortality.

RESULTS

We identified 230 patients with CDI meeting inclusion criteria during the study period. Of these, 124 (54%) were appropriately treated, 46 (20%) were under-treated and 60 (26%) were over-treated. All-cause 90 day mortality was 17.4% overall; 43.5% in the under-treated group versus 12.9% in those appropriately treated (P < 0.0001) and 10.9% in those appropriately treated plus over-treated (P < 0.0001). Similarly, 90 day mortality attributed to CDI was 21.7% in those under-treated versus 8.9% in those appropriately treated (P = 0.03) and 8.2% in those either appropriately treated or over-treated (P = 0.015). Severe-complicated CDI occurred in 46 patients. In this subgroup, there was a non-significant trend towards increased mortality in under-treated patients (56.7%) compared with appropriately treated patients (37.5%, P = 0.35). Under-treatment was also associated with a higher rate of CDI-related ICU transfer (17.4% versus 4.8% in those appropriately treated, P = 0.023).

CONCLUSIONS

Adherence to CDI treatment guidelines is associated with improved outcomes especially in those with severe disease. Increased emphasis on provision of appropriate, guideline-based CDI treatment appears warranted.

Production, Crystallization and Structure Determination of C. difficile PPEP-1 via Microseeding and Zinc-SAD

New therapies are needed to treat Clostridium difficile infections that are a major threat to human health. The C. difficile metalloprotease PPEP-1 is a target for future development of inhibitors to decrease the virulence of the pathogen. To perform biophysical and structural characterization as well as inhibitor screening, large amounts of pure and active protein will be needed. We have developed a protocol for efficient production and purification of PPEP-1 by the use of E. coli as the expression host yielding sufficient amounts and purity of protein for crystallization and structure determination. Additionally, using microseeding, highly intergrown crystals of PPEP-1 can be grown to well-ordered crystals suitable for X-ray diffraction analysis. The methods could also be used to produce other recombinant proteins and to study the structures of other proteins producing intergrown crystals.

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.

Determining the cause of recurrent Clostridium difficile infection using whole genome sequencing

Understanding the contribution of relapse and reinfection to recurrent Clostridium difficile infection (CDI) has implications for therapy and infection prevention, respectively. We used whole genome sequencing to determine the relation of C. difficile strains isolated from patients with recurrent CDI at an academic medical center in the United States. Thirty-five toxigenic C. difficile isolates from 16 patients with 19 recurrent CDI episodes with median time of 53.5days (range, 13-362) between episodes were whole genome sequenced on the Illumina MiSeq platform. In 84% (16) of recurrences, the cause of recurrence was relapse with prior strain of C. difficile. In 16% (3) of recurrent episodes, reinfection with a new strain of C. difficile was the cause. In conclusion, the majority of CDI recurrences at our institution were due to infection with the same strain rather than infection with a new strain.

Cost Averted With Timely Fecal Microbiota Transplantation in the Management of Recurrent Clostridium difficile Infection in Alberta, Canada

BACKGROUND

Fecal microbiota transplantation (FMT) is highly effective in treating recurrent Clostridium difficile infection (RCDI). However, the ideal timing for offering FMT remains to be determined. Furthermore, the direct medical costs averted with timely FMT have not been examined.

METHODS

A retrospective review of the Edmonton FMT program database included patients who received FMT for RCDI (October 2012 to September 2014). They were divided into 2 groups: those who received FMT after 2 recurrences (the timely FMT group) and those who received FMT after at least 3 recurrences (the delayed FMT group). The primary outcome was the difference in direct medical costs related to hospital admissions and emergency room visits due to CDI between the 2 groups. The secondary outcomes were RCDI cure rate and duration of RCDI in each group.

RESULTS

A total of 75 patients were included: 30 received timely FMT, whereas 45 received delayed FMT. The mean difference in hospital length of stay and emergency room visits related to CDI were 13.8 days shorter and 1.3 visits fewer with timely FMT, associated with a mean cost saving of $29,842 per patient. Sensitivity analysis was performed to examine the effect of outliers and comorbities on the differential costs, and it was found that the differences in average cost per patient were more pronounced in those with Charlson comorbidity index ≥3 compared with those with scores of 0 to 2. The cure rate was 94% (timely FMT group) and 93% (delayed FMT group). The mean duration of RCDI was 109 days (timely FMT group) and 281 days (delayed FMT group).

CONCLUSIONS

Timely FMT can provide significant cost savings to health-care systems, especially for patients with multiple comorbidities.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Ultrastructure Variability of the Exosporium Layer of Clostridium difficile Spores from Sporulating Cultures and Biofilms

The anaerobic sporeformer Clostridium difficile is the leading cause of nosocomial antibiotic-associated diarrhea in developed and developing countries. The metabolically dormant spore form is considered the morphotype responsible for transmission, infection, and persistence, and the outermost exosporium layer is likely to play a major role in spore-host interactions during recurrent infections, contributing to the persistence of the spore in the host. A recent study (M. Pizarro-Guajardo, P. Calderón-Romero, P. Castro-Córdova, P. Mora-Uribe, and D. Paredes-Sabja, Appl Environ Microbiol 82:2202-2209, 2016, http://dx.doi.org/10.1128/AEM.03410-15) demonstrated by transmission electron microscopy the presence of two ultrastructural morphotypes of the exosporium layer in spores formed from the same sporulating culture. However, whether these distinct morphotypes appeared due to purification techniques and whether they appeared during biofilm development remain unclear. In this communication, we demonstrate through transmission electron microscopy that these two exosporium morphotypes are formed under sporulation conditions and are also present in spores formed during biofilm development. In summary, this work provides definitive evidence that in a population of sporulating cells, spores with a thick outermost exosporium layer and spores with a thin outermost exosporium layer are formed.

IMPORTANCE

Clostridium difficile spores are recognized as the morphotype of persistence and transmission of C. difficile infections. Spores of C. difficile are intrinsically resistant to all known antibiotic therapies. Development of spore-based removal strategies requires a detailed knowledge of the spore surface for proper antigen selection. In this context, in this work we provide definitive evidence that two types of spores, those with a thick outermost exosporium layer and those with a thin outermost exosporium layer, are formed in the same C. difficile sporulating culture or during biofilm development.

Cost of hospital management of Clostridium difficile infection in United States-a meta-analysis and modelling study

Background

Clostridium difficile infection (CDI) is the leading cause of infectious nosocomial diarrhoea but the economic costs of CDI on healthcare systems in the US remain uncertain.

Methods

We conducted a systematic search for published studies investigating the direct medical cost associated with CDI hospital management in the past 10 years (2005–2015) and included 42 studies to the final data analysis to estimate the financial impact of CDI in the US. We also conducted a meta-analysis of all costs using Monte Carlo simulation.

Results

The average cost for CDI case management and average CDI-attributable costs per case were $42,316 (90 % CI: $39,886, $44,765) and $21,448 (90 % CI: $21,152, $21,744) in 2015 US dollars. Hospital-onset CDI-attributable cost per case was $34,157 (90 % CI: $33,134, $35,180), which was 1.5 times the cost of community-onset CDI ($20,095 [90 % CI: $4991, $35,204]). The average and incremental length of stay (LOS) for CDI inpatient treatment were 11.1 (90 % CI: 8.7–13.6) and 9.7 (90 % CI: 9.6–9.8) days respectively. Total annual CDI-attributable cost in the US is estimated US$6.3 (Range: $1.9–$7.0) billion. Total annual CDI hospital management required nearly 2.4 million days of inpatient stay.

Conclusions

This review indicates that CDI places a significant financial burden on the US healthcare system. This review adds strong evidence to aid policy-making on adequate resource allocation to CDI prevention and treatment in the US. Future studies should focus on recurrent CDI, CDI in long-term care facilities and persons with comorbidities and indirect cost from a societal perspective. Health-economic studies for CDI preventive intervention are needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1786-6) contains supplementary material, which is available to authorized users.

Challenges in management of recurrent and refractory Clostridium difficile infection

Clostridium difficile infection (CDI) is the most common nosocomial infection in the United States and is associated with a high mortality. One quarter of patients treated for CDI have at least one recurrence. Spore persistence, impaired host immune response and alteration in the gastrointestinal microbiome due to antibiotic use are factors in recurrent disease. We review the etiology of recurrent CDI and best approaches to management including fecal microbiota transplantation.

Optimizing the diagnostic testing of Clostridium difficile infection

INTRODUCTION

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

AREAS COVERED

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

Cost-Effectiveness Analysis of the Use of Probiotics for the Prevention of Clostridium difficile-Associated Diarrhea in a Provincial Healthcare System

OBJECTIVE To conduct a full economic evaluation assessing the costs and consequences related to probiotic use for the primary prevention of Clostridium difficile-associated diarrhea (CDAD). DESIGN Cost-effectiveness analysis using decision analytic modeling. METHODS A cost-effectiveness analysis was used to evaluate the risk of CDAD and the costs of receiving oral probiotics versus not over a time horizon of 30 days. The target population modeled was all adult inpatients receiving any therapeutic course of antibiotics from a publicly funded healthcare system perspective. Effectiveness estimates were based on a recent systematic review of probiotics for the primary prevention of CDAD. Additional estimates came from local data and the literature. Sensitivity analyses were conducted to assess how plausible changes in variables impacted the results. RESULTS Treatment with oral probiotics led to direct costs of CDN $24 per course of treatment per patient. On average, patients treated with oral probiotics had a lower overall cost compared with usual care (CDN $327 vs $845). The risk of CDAD was reduced from 5.5% in those not receiving oral probiotics to 2% in those receiving oral probiotics. These results were robust to plausible variation in all estimates. CONCLUSIONS Oral probiotics as a preventive strategy for CDAD resulted in a lower risk of CDAD as well as cost-savings. The cost-savings may be greater in other healthcare systems that experience a higher incidence and cost associated with CDAD. Infect Control Hosp Epidemiol 2016;37:1079-1086.

Clostridium difficile infection in patients hospitalized with type 2 diabetes mellitus and its impact on morbidity, mortality, and the costs of inpatient care

AIMS

Type 2 diabetes mellitus (T2DM) is often complicated by infections leading to hospitalization, increased morbidity, and mortality. Not much is known about the impact of Clostridium difficile infection (CDI) on health outcomes in hospitalized patients with T2DM. We estimated the prevalence and temporal trends of CDI; evaluated the associations between CDI and in-hospital mortality, length of stay (LOS), and the costs of inpatient care; and compared the impact of CDI with that of other infections commonly seen in patients with T2DM.

METHODS

We conducted a cross-sectional analysis using data from the Nationwide Inpatient Sample among patients ⩾18years with T2DM and generalized linear regression was used to analyze associations and jointpoint regression for trends.

RESULTS

The prevalence of CDI was 6.8 per 1000 hospital discharges. Patients with T2DM and CDI had increased odds of in-hospital mortality (OR, 3.63; 95% CI 3.16, 4.17). The adjusted mean LOS was higher in patients with CDI than without CDI (11.9 vs. 4.7days). That translated to average hospital costs of $23,000 and $9100 for patients with and without CDI, respectively. The adjusted risk of mortality in patients who had CDI alone (OR 3.75; 95% CI 3.18, 4.41) was similar to patients who had CDI in addition to other common infections (OR 3.25; 95% CI 2.58, 4.10).

CONCLUSION

CDI is independently associated with poorer health outcomes in patients with T2DM. We recommend close surveillance for CDI in hospitalized patients and further studies to determine the cost effectiveness of screening for CDI among patients with T2DM.