Epidemiology and Recurrence Rates of Clostridium difficile Infections in Germany: A Secondary Data Analysis

Estimating excess mortality and economic burden of Clostridioides difficile infections and recurrences during 2015-2019: the RECUR Germany study

BACKGROUND

Clostridioides difficile infections (CDIs) and recurrences (rCDIs) remain a major public health challenge due to substantial mortality and associated costs. This study aims to generate real-world evidence on the mortality and economic burden of CDI in Germany using claims data between 2015 and 2019.

METHODS

A longitudinal and matched cohort study using retrospective data from Statutory Health Insurance (SHI) was conducted in Germany with the BKK database. Adults diagnosed with CDI in hospital and community settings between 2015 and 2018 were included in the study. Patients had a minimum follow-up of 12-months. All-cause mortality was described at 6-, 12-, and 24-months. Healthcare resource usage (HCRU) and associated costs were assessed at 12-months of follow-up. A cohort of non-CDI patients matched by demographic and clinical characteristics was used to assess excess mortality and incremental costs of HCRU. Up to three non-CDI patients were matched to each CDI patient.

RESULTS

A total of 9,977 CDI patients were included in the longitudinal cohort. All-cause mortality was 32%, 39% and 48% at 6-, 12-, and 24-months, respectively, with minor variations by number of rCDIs. When comparing matched CDI (n = 5,618) and non-CDI patients (n = 16,845), CDI patients had an excess mortality of 2.17, 1.35, and 0.94 deaths per 100 patient-months, respectively. HCRU and associated costs were consistently higher in CDI patients compared to non-CDI patients and increased with recurrences. Total mean and median HCRU cost per patient during follow-up was €12,893.56 and €6,050 in CDI patients, respectively, with hospitalisations representing the highest proportion of costs. A total mean incremental cost per patient of €4,101 was estimated in CDI patients compared to non-CDI patients, increasing to €13,291 in patients with ≥ 3 rCDIs.

CONCLUSIONS

In this real-world study conducted in Germany, CDI was associated with increased risk of death and substantial costs to health systems due to higher HCRU, especially hospitalisations. HCRU and associated costs were exacerbated by rCDIs.

A cost-utility analysis of two Clostridioides difficile infection guideline treatment pathways

OBJECTIVES

Treatment guidelines are key drivers of prescribing practice in the management of Clostridioides difficile infection (CDI), but recommendations on best practice can vary. We conducted a cost-utility analysis to compare the treatment pathway recommended by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guideline with the pathway proposed by the National Institute for Health and Care Excellence (NICE) guideline, from the perspective of the UK National Health Service.

METHODS

A decision tree modelling approach was adopted to reflect the treatment pathway for CDI as outlined in ESCMID and NICE guidelines. Patients experiencing a CDI infection received up to three treatments per infection to achieve a response and could subsequently experience up to two recurrences. Data on patient demographics, treatment response, recurrence, utilities, CDI-related mortality, and costs were taken from published literature.

RESULTS

The ESCMID treatment pathway was cost-effective versus the NICE treatment pathway at a threshold of £20 000 per quality-adjusted life year gained, with an incremental cost-effectiveness ratio of £4931. Cost-effectiveness was driven by differences in index infection recommendations (ESCMID recommends fidaxomicin as first-line treatment whereas NICE recommends vancomycin). The model results were robust to variations in inputs investigated in scenarios and sensitivity analyses, and probabilistic sensitivity analysis demonstrated that the ESCMID guideline treatment strategy had a 100% likelihood of being cost-effective versus the NICE treatment strategy.

DISCUSSION

Compared with the NICE guideline, the ESCMID guideline recommendations for treating an index CDI represent the most cost-effective use of healthcare resources from the perspective of the UK National Health Service.

Association of ward-level antibiotic consumption with healthcare-associated Clostridioides difficile infections: an ecological study in five German university hospitals, 2017-2019

OBJECTIVES

To analyse the influence of antibiotic consumption on healthcare-associated healthcare onset (HAHO) Clostridioides difficile infection (CDI) in a German university hospital setting.

METHODS

Monthly ward-level antibiotic consumption measured in DDD/100 patient days (pd) and CDI surveillance data from five university hospitals in the period 2017 through 2019 were analysed. Uni- and multivariable analyses were performed with generalized estimating equation models.

RESULTS

A total of 225 wards with 7347 surveillance months and 4 036 602 pd participated. With 1184 HAHO-CDI cases, there was a median incidence density of 0.17/1000 pd (IQR 0.03-0.43) across all specialties, with substantial differences among specialties. Haematology-oncology wards showed the highest median incidence density (0.67/1000 pd, IQR 0.44-1.01), followed by medical ICUs (0.45/1000 pd, IQR 0.27-0.73) and medical general wards (0.32/1000 pd, IQR 0.18-0.53). Multivariable analysis revealed carbapenem (mostly meropenem) consumption to be the only antibiotic class associated with increased HAHO-CDI incidence density. Each carbapenem DDD/100 pd administered increased the HAHO-CDI incidence density by 1.3% [incidence rate ratio (IRR) 1.013; 95% CI 1.006-1.019]. Specialty-specific analyses showed this influence only to be valid for haematological-oncological wards. Overall, factors like ward specialty (e.g. haematology-oncology ward IRR 2.961, 95% CI 2.203-3.980) or other CDI cases on ward had a stronger influence on HAHO-CDI incidence density (e.g. community-associated CDI or unknown association case in same month IRR 1.476, 95% CI 1.242-1.755) than antibiotic consumption.

CONCLUSIONS

In the German university hospital setting, monthly ward-level carbapenem consumption seems to increase the HAHO-CDI incidence density predominantly on haematological-oncological wards. Furthermore, other patient-specific factors seem to be equally important to control HAHO-CDI.

Anticoagulant Treatment Adherence and Persistence in German Patients with Atrial Fibrillation

INTRODUCTION

Treatment adherence and persistence impact the effectiveness of edoxaban for the prevention of thromboembolism in patients with atrial fibrillation (AF). The objective of this analysis was to assess adherence and persistence of edoxaban vs. other non-vitamin K antagonist oral anticoagulants (NOACs) and vitamin K antagonists (VKAs).

METHODS

Utilizing a German claims database, adults with AF with the first pharmacy claim identified for edoxaban, apixaban, dabigatran, rivaroxaban, or VKAs from January 2013 to December 2017 were included in a propensity score-matched analysis. The first pharmacy claim was the index claim. Adherence (i.e., proportion of days covered [PDC]) and persistence (proportion of patients who continued therapy) were compared between edoxaban and other therapies. Patients receiving once-daily (QD) vs. twice-daily (BID) NOAC were also analyzed.

RESULTS

Overall, 21,038 patients were included (1236 edoxaban, 6053 apixaban, 1306 dabigatran, 7013 rivaroxaban, and 5430 VKA). After matching, baseline characteristics were well balanced across cohorts. Adherence was significantly higher for edoxaban vs. apixaban, dabigatran, and VKAs (all P < 0.0001). Significantly more edoxaban patients continued therapy vs. rivaroxaban (P = 0.0153), dabigatran (P < 0.0001), and VKAs (P < 0.0001). Time to discontinuation was significantly longer for edoxaban vs. dabigatran, rivaroxaban, and VKAs (all P < 0.0001). More patients receiving NOACs QD had a PDC ≥ 0.8 compared with those receiving NOACs BID (65.3 vs. 49.6%, respectively; P < 0.05); persistence rates were comparable between QD and BID groups.

CONCLUSIONS

Patients with AF receiving edoxaban had significantly higher adherence and persistence compared with those receiving VKAs. This trend was also seen in NOAC QD regimens vs. NOAC BID regimens for adherence. These results provide insight into how adherence and persistence may contribute to the effectiveness of edoxaban for stroke prevention in patients with AF in Germany.

Epidemiology and Risk Factors of Clostridioides difficile Infections in Germany: A Health Claims Data Analysis

INTRODUCTION

Clostridioides difficile infection (CDI) is increasingly recognized as a public health threat at the community level in addition to being one of the most common causes of healthcare-associated infections. In Germany, the epidemiology of CDI is primarily informed by national hospital-based CDI surveillance. We used health claims data from Germany to obtain valuable insights on population-level disease burden and risk factors for CDI.

METHODS

This was a retrospective cohort study using a representative sample from the InGef research database. Overall and age- and sex-stratified CDI incidence rates were estimated for German adults from 2013 to 2017 using different case definitions (i.e., main, broad, strict), and further stratified by setting (inpatient versus outpatient). Risk factors for CDI were assessed for the 2013-2016 period.

RESULTS

The CDI incidence rate was high but declined by 15.3% from 2013 [141 (95% confidence interval, CI 137-145) cases/100,000 person-years] to 2017 [120 (95% CI 116-123)]. Annual CDI incidence rates were higher in female patients and the elderly. The most important risk factors for CDI were chronic inflammatory bowel disease [odds ratio (OR) 4.7, 95% CI 4.0-5.5], chemotherapy (OR 4.7, 95% CI 4.1-5.2), chronic kidney disease (OR 2.9, 95% CI 2.6-3.3), and ciprofloxacin receipt (OR 2.6, 95% CI 2.4-2.8).

CONCLUSIONS

Despite prevention strategies leading to declining incidence, CDI remains an important public health threat in Germany, with a high burden in the hospital setting and an outpatient epidemiology that is poorly understood. These findings, which are relevant both regionally and globally, can be used as a basis for further research on the full burden of CDI in Germany.

Epidemiology of Clostridioides difficile Infections in Germany, 2010-2019: A Review from Four Public Databases

INTRODUCTION

Clostridioides difficile infection (CDI) is a recognized global threat especially for vulnerable populations. It is of particular concern to healthcare providers as it is found in both hospital and community settings, with severe courses, frequent recurrence, high mortality and substantial financial impact on the healthcare system. The CDI burden in Germany has been described and compared by analysing data from four different public databases.

METHODS

Data on hospital burden of CDI have been extracted, compared, and discussed from four public databases for the years 2010-2019. Hospital days due to CDI were compared to established vaccine preventable diseases, such as influenza and herpes zoster, and also to CDI hospitalisations in the United States (US).

RESULTS

All four databases reported comparable incidences and trends. Beginning in 2010, population-based hospitalised CDI incidence increased to a peak of > 137/100,000 in 2013. Then, incidence declined to 81/100,000 in 2019. Hospitalised patients with CDI were predominantly > 50 years of age. The population-based incidence of severe CDI was between 1.4 and 8.4/100,000 per year. Recurrence rates were between 5.9 to 6.5%. More than 1,000 CDI deaths occurred each year, with a peak of 2,666 deaths in 2015. Cumulative CDI patient days (PD) were between 204,596 and 355,466 each year, which exceeded cumulated PD for influenza and herpes zoster in most years, though year-to-year differences were observed. Finally, hospitalized CDI incidence was higher in Germany than in the US, where the disease is well recognized as a public health threat.

CONCLUSIONS

All four public sources documented a decline in CDI cases since 2013, but the disease burden remains substantial and warrants continued attention as a severe public health challenge.

Association between epidemiologic case definition categories and adverse clinical outcome in patients with Clostridiodes difficile infection in San Francisco County, California: a five-year retrospective cohort study

BACKGROUND

Understanding the predictors of adverse clinical outcomes following incident Clostridiodes difficile infection (CDI) can help clinicians identify which patients are at risk of complications and help prioritize the provision of their care. In this study, we assessed the associations between epidemiologic case definition categories and adverse clinical outcomes in patients with CDI in San Francisco County, California.

METHODS

We conducted a retrospective cohort study using CDI surveillance data (n = 3274) from the California Emerging Infections Program for the time period 2016 to 2020. After independent associations were established, two multivariable logistic and log-binomial regression models were constructed for the final statistical analysis.

RESULT

The mean cumulative incidence of CDI cases was 78.8 cases per 100,000 population. The overall recurrence rate and the 30-day all-cause mortality rate were 11.1% and 4.5%, respectively. After adjusting for potential confounders, compared to the community associated CDI cases, healthcare facility onset (AOR = 3.1; 95% CI [1.3-7]) and community-onset-healthcare facility associated (AOR = 2.4; 95% CI [1.4-4.3]) CDI cases were found to have higher odds of all-cause 30-day mortality. Community onset-healthcare facility-associated CDI case definition category was found to be significantly associated with an increased risk of recurrence of CDI (ARR = 1.7; 95% CI [1.2-2.4]).

CONCLUSION

Although the incidence of community-associated CDI cases has been rising, the odds of all-cause 30-day mortality and the risk of recurrent CDI associated with these infections are lower than healthcare facility onset and community-onset healthcare facility-associated CDI cases.

Carbapenem-resistant gram-negative bacteria in Germany: incidence and distribution among specific infections and mortality: an epidemiological analysis using real-world data

PURPOSE

Infections with carbapenem-resistant gram-negative bacteria (in Germany classified as 4MRGN) are a growing threat in clinical care. This study was undertaken to understand the overall burden of 4MRGN infections in Germany in the context of a Health Technology Appraisal (HTA) for Ceftazidime/Avibactam (CAZ/AVI). Besides, the incidences mortality was an endpoint of interest.

METHODS

To assess infections with carbapenem-resistant gram-negative bacteria and related mortality, three different data sources have been used. From the German statistics office (DESTATIS) data have been retrieved to obtain the overall frequency these pathogens. Via two other databases, the German analysis database (DADB) and a Benchmarking of > 200 hospitals in a representative sample (BM-DB), the distribution of the infections and the mortality have been analyzed.

RESULTS

DESTATIS data showed a total of 11,863 carbapenem-resistant gram-negative bacteria codings, of which 10,348 represent infections and 1515 carriers. The most frequent infections were complicated urinary tract infections (cUTI) (n = 2,337), followed by pneumonia (n = 1006) and intra-abdominal infections (n = 730). A considerable amount of patients had multiple infections in one hospital episode (n = 1258). In-hospital mortality was 18.6% in DADB and 14.3% in the BM-DB population, respectively. In cases with additional bloodstream infections, DADB mortality was correspondingly higher at 33.0%. DADB data showed an incremental mortality increase of 5.7% after 30 days and 10.0% after 90 days resulting in a cumulative 90 day mortality of 34.3%.

CONCLUSIONS

Infections with carbapenem-resistant gram-negative bacteria are still rare (6.8-12.4 per 100,000) but show a significant increase in mortality compared to infections with more sensitive pathogens. Using different data sources allowed obtaining a realistic picture.

Opportunities for Nanomedicine in Clostridioides difficile Infection

Clostridioides difficile, a spore-forming bacterium, is a nosocomial infectious pathogen which can be found in animals as well. Although various antibiotics and disinfectants were developed, C. difficile infection (CDI) remains a serious health problem. C. difficile spores have complex structures and dormant characteristics that contribute to their resistance to harsh environments, successful transmission and recurrence. C. difficile spores can germinate quickly after being exposed to bile acid and co-germinant in a suitable environment. The vegetative cells produce endospores, and the mature spores are released from the hosts for dissemination of the pathogen. Therefore, concurrent elimination of C. difficile vegetative cells and inhibition of spore germination is essential for effective control of CDI. This review focused on the molecular pathogenesis of CDI and new trends in targeting both spores and vegetative cells of this pathogen, as well as the potential contribution of nanotechnologies for the effective management of CDI.

Osteoporotic fractures and subsequent fractures: imminent fracture risk from an analysis of German real-world claims data

Purpose

In osteoporosis, prior fracture is a strong predictor of subsequent fracture. This study aimed to assess the imminent risk of subsequent fracture following an initial fracture in osteoporosis patients in Germany, and to identify clinical and demographic characteristics that are independently associated with subsequent fracture risk.

Methods

In this retrospective, observational cohort study using German real-world claims data, male and female patients aged ≥ 50 years with osteoporosis who experienced an initial (“index”) hip/femur, vertebral, forearm/wrist/hand or shoulder/upper arm fracture between 2010 and 2014 were included. The incidence and timing of subsequent fractures during a 1-year follow-up period were analyzed. Independent risk factors for subsequent fracture were identified by multivariate regression analysis.

Results

A total of 18,354 patients (mean age: 77 years; standard deviation: 9.8) were included. Of these, 2918 (15.9%) suffered a subsequent fracture during the 1-year follow-up period. The incidence of subsequent fracture was higher following an index vertebral fracture (18.0%) than after an index forearm/wrist/hand fracture (14.1%) or index hip/femur fracture (12.1%). Subsequent 1-year fracture incidence was generally higher in older patients. Index fracture type, age, epilepsy/use of antiepileptics, and heart failure were all independently associated with subsequent fracture risk.

Conclusion

Osteoporosis patients in Germany are at imminent risk of subsequent fracture during the first year following an initial fracture. They should be targeted for immediate post-fracture treatment to reduce the risk of further fractures, especially in the presence of specific risk factors such as old age or index vertebral fracture.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00404-021-06123-6.

Molecular epidemiology and antimicrobial resistance of Clostridioides difficile in Germany, 2014-2019

Clostridioides difficile is a Gram positive spore-forming rod and mainly responsible for nosocomial diarrhea in developed nations. Molecular and antimicrobial surveillance is important for monitoring the strain composition including genotypes of high epidemiological importance such as ribotype 027 (RT027) and corresponding resistance patterns. 1535 isolates obtained from samples sent between 2014 and 2019 to the German National Reference Center (NRC) for diagnostic reasons (NRC strain set), and 1143 isolates from a Tertiary Care University Center in Saarland, Germany (non-NRC strain set), were evaluated using antibiotic susceptibility testing and ribotyping. In the NRC strain set, RT027 overtook RT001, the main RT found in the preceding studies, and dominated with 36.2%, followed by RT001 (13.3%), and RT014 (8.5%). Of note, since 2016 a constant decrease of RT027 could be noticed. In the non-NRC strain set a large strain diversity was present with RT014 (18%) and RT001 (8.9%) being most prevalent. In NRC samples, resistance towards metronidazole, vancomycin, moxifloxacin, clarithromycin and rifampicin was 2.7%, 0%, 57.1%, 53.2% and 19.2%, respectively. Metronidazole resistance was almost exclusively found in RT027 isolates. Rifampicin resistance was also observed predominantly in isolates of RT027, constituting an almost four-fold increase, when compared to preceeding studies in this region. In conclusion these data demonstrate that RT027 is a driver for rifampicin and metronidazole resistance, underlining the importance of continuous surveillance efforts.

Update on Treatment of Clostridioides difficile Infection

Clostridioides difficile infection (CDI) is the leading cause of health care-associated infections in the United States. The increasing incidence and recurrence rates of CDI together with its associated morbidity and mortality are great concerns. Newer treatment methods, such as narrow-spectrum antibiotics, monoclonal antibodies, and microbial replacement therapies, are being developed and implemented. We searched PubMed to identify published literature from 2010 to 2018 using the following keywords: Clostridium difficile, treatment, and therapy. Cited references were also used to identify relevant literature. This review focuses on the current standard of therapy and emerging therapies for CDI and summarizes the updated guidelines on treatment of CDI.

Gastrointestinal Microbiome - What We Need to Know in Clinical Practice

Human gut microbiota plays an important role in individual health. When the balance between host and gut microbiota is disrupted, changes in microbiota composition and function occur, which is referred as dysbiosis. Environmental factors as diet, proton pump inhibitors, and antibiotics can lead to a permanent dysbiotic disruption. Clarification of these imbalances was made possible by recent advances in genome sequencing methods that supported acknowledgment of the interplay between microbiome and intestinal and extraintestinal disorders. This review focuses on the microbiota impact in inflammatory bowel disease, gastric cancer, colorectal cancer, nonalcoholic fatty liver disease (NAFLD), irritable bowel syndrome (IBS), and Clostridium difficile infection (CDI). Furthermore, novel therapies are summarized. Fecal microbiota transplant (FMT) is a successful and established therapy in recurrent CDI, and its application in other dysbiosis-related diseases is attracting enormous interest. Pre- and probiotics target microbial rebalance and have positive effects mainly in NAFLD, ulcerative colitis, IBS, and CDI patients. Promising anticarcinogenic effects have also been demonstrated in animal models. The literature increasingly describes microbial changes in many dysbiotic disorders and shows what needs to be treated. However, probiotics and FMT application in clinical practice suffers from a shortage of randomized controlled trials with standardized therapy regimens to support their recommendation.

Incidence of and risk factors for recurrent Clostridioidesdifficile infection in Japan using a claims database: A retrospective cohort study

This retrospective cohort study aimed to determine the incidence rates of and risk factors for recurrent Clostridioides difficile infection (rCDI) in Japan using a claims database. Inpatients of any age with ≥1 record of C. difficile infection (CDI) during the study period (January 2012-September 2016) were analyzed. We estimated the incidence rate of health care onset, health care facility associated (HO-HCFA) primary CDI and HO-HCFA rCDI for each of the first to fifth recurrences. Risk factors for the first recurrence were investigated using a univariate, and subsequently, a multivariable Cox regression model. The incidence rates (95% confidence interval [CI]) of CDI and HO-HCFA CDI were 2.43 (2.40-2.46) and 1.26 (1.24-1.28) cases per 10,000 inpatient-days, respectively. Among the 11,287 inpatients with ≥1 HO-HCFA CDI, 1424 patients had ≥1 recurrent episode (12.6% [95% CI 12.0-13.2]). The rCDI incidence rates consistently increased, with the number of recurrences ranging from 29.2 to 181.8 cases per 10,000 inpatient-days. The multivariable analysis revealed five risk factors (hazard ratio [95% CI]): age ≥65 years (vs. <65 years; 65-74 years, 1.275 [1.048-1.551]; 75-79 years, 1.612 [1.315-1.975]; ≥80 years, 2.110 [1.776-2.507]); cephalosporin use both before (vs. without cephalosporin; 1.241 [1.098-1.402]) and during the primary CDI (vs. without cephalosporin; 1.137 [1.011-1.279]); higher number of comorbidities (vs. ≤10 comorbidities; 11-14 comorbidities: 1.336 [1.131-1.580]; 15-20 comorbidities: 1.433 [1.219-1.685]; ≥21 comorbidities: 1.310 [1.099-1.561]); and gastrointestinal surgery (vs. without surgery; 0.823 [0.701-0.965]). In conclusion, CDI recurred in some Japanese patients, and the incidence rates increased with the number of recurrences. Special care is needed in patients aged ≥65 years, those with a higher number (>10) of comorbidities, and those who have received cephalosporin before or during the primary CDI.

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

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

Inhibitory Effect of Ursodeoxycholic Acid on Clostridium difficile Germination Is Insufficient to Prevent Colitis: A Study in Hamsters and Humans

Introduction: Bile acids (BA) influence germination and growth of Clostridium difficile. Ursodeoxycholic acid (UDCA), a BA minor in human, used for cholestatic liver diseases, inhibits germination and growth of C. difficile in vitro, but was never tested in vivo with an infectious challenge versus control. We hypothesized that UDCA could prevent CDI. We evaluated the effects of UDCA on C. difficile in vitro and in hamsters, with pharmacokinetics study and with an infectious challenge. Then, we studied CDI incidence in UDCA–treated patients.

Methods: We evaluated germination and growth of C. difficile, with 0.01, 0.05, and 0.1% UDCA. We analyzed fecal BA of hamsters receiving antibiotics and UDCA (50 mg/kg/day), antibiotics, or UDCA alone. Then, we challenged with spores of C. difficile at D6 hamsters treated with UDCA (50 mg/kg/day) from D1 to D13, versus control. In human, we analyzed the database of a cohort on CDI in acute flares of inflammatory bowel disease (IBD). As PSC-IBD patients were under UDCA treatment, we compared PSC-IBD patients to IBD patients without PSC.

Results:In vitro, UDCA inhibited germination and growth of C. difficile at 0.05 and 0.1%, competing with 0.1% TCA (with 0.1%: 0.05% ± 0.05% colony forming unit versus 100% ± 0%, P < 0.0001). In hamsters, UDCA reached high levels only when administered with antibiotics (43.5% UDCA at D5). Without antibiotics, UDCA was in small amount in feces (max. 4.28%), probably because of UDCA transformation into LCA by gut microbiota. During infectious challenge, mortality was similar in animals treated or not with UDCA (62.5%, n = 5/8, P = 0.78). UDCA percentage was high, similar and with the same kinetics in dead and surviving hamsters. However, dead hamsters had a higher ratio of primary over secondary BA compared to surviving hamsters. 9% (n = 41/404) of IBD patients without PSC had a CDI, versus 25% (n = 4/12) of PSC-IBD patients treated with UDCA.

Conclusion: We confirmed the inhibitory effect of UDCA on growth and germination of C. difficile in vitro, with 0.05 or 0.1% UDCA. However, in our hamster model, UDCA was inefficient to prevent CDI, despite high levels of UDCA in feces. Patients with PSC-IBD treated with UDCA did not have less CDI than IBD patients.

Updates to Clostridium difficile Spore Germination

Germination of Clostridium difficile spores is a crucial early requirement for colonization of the gastrointestinal tract. Likewise, C. difficile cannot cause disease pathologies unless its spores germinate into metabolically active, toxin-producing cells. Recent advances in our understanding of C. difficile spore germination mechanisms indicate that this process is both complex and unique. This review defines unique aspects of the germination pathways of C. difficile and compares them to those of two other well-studied organisms, Bacillus anthracis and Clostridium perfringensC. difficile germination is unique, as C. difficile does not contain any orthologs of the traditional GerA-type germinant receptor complexes and is the only known sporeformer to require bile salts in order to germinate. While recent advances describing C. difficile germination mechanisms have been made on several fronts, major gaps in our understanding of C. difficile germination signaling remain. This review provides an updated, in-depth summary of advances in understanding of C. difficile germination and potential avenues for the development of therapeutics, and discusses the major discrepancies between current models of germination and areas of ongoing investigation.

Disease Burden of Clostridium difficile Infections in Adults, Hong Kong, China, 2006-2014

Cross-sectional studies suggest an increasing trend in incidence and relatively low recurrence rates of Clostridium difficile infections in Asia than in Europe and North America. The temporal trend of C. difficile infection in Asia is not completely understood. We conducted a territory-wide population-based observational study to investigate the burden and clinical outcomes in Hong Kong, China, over a 9-year period. A total of 15,753 cases were identified, including 14,402 (91.4%) healthcare-associated cases and 817 (5.1%) community-associated cases. After adjustment for diagnostic test, we found that incidence increased from 15.41 cases/100,000 persons in 2006 to 36.31 cases/100,000 persons in 2014, an annual increase of 26%. This increase was associated with elderly patients, for whom incidence increased 3-fold over the period. Recurrence at 60 days increased from 5.7% in 2006 to 9.1% in 2014 (p<0.001). Our data suggest the need for further surveillance, especially in Asia, which contains ≈60% of the world’s population.

Recent Progress for the Effective Prevention and Treatment of Recurrent Clostridium difficile Infection

Recurrence occurs in approximately 25% of all cases of Clostridium difficile infection (CDI) and poses a unique clinical challenge. Traditionally, treatment options of CDI have been limited to regimes of established antibiotics (eg, pulsed/tapered vancomycin) but faecal transplantation is emerging as a useful alternative. In recent years, promising new strategies have emerged for effective prevention of recurrent CDI (rCDI) including new antimicrobials (eg, fidaxomicin) and monoclonal antibodies (eg, bezlotoxumab). Despite promising progress in this area, obstacles remain for making the best use of these resources due to uncertainty over patient selection. This commentary describes the current epidemiology of rCDI, its clinical impact and risk factors, some of the measures used for treating and preventing rCDI, and some of the emerging treatment options. It then describes some of the obstacles that need to be overcome.

Derivation and Validation of a Clostridium difficile Infection Recurrence Prediction Rule in a National Cohort of Veterans

STUDY OBJECTIVE

Prior studies have identified risk factors for recurrent Clostridium difficile infection (CDI), but few studies have integrated these factors into a clinical prediction rule that can aid clinical decision-making. The objectives of this study were to derive and validate a CDI recurrence prediction rule to identify patients at risk for first recurrence in a national cohort of veterans.

DESIGN

Retrospective cohort study.

DATA SOURCE

Veterans Affairs Informatics and Computing Infrastructure.

PATIENTS

A total of 22,615 adult Veterans Health Administration beneficiaries with first-episode CDI between October 1, 2002, and September 30, 2014; of these patients, 7538 were assigned to the derivation cohort and 15,077 to the validation cohort.

MEASUREMENTS AND MAIN RESULTS

A 60-day CDI recurrence prediction rule was created in a derivation cohort using backward logistic regression. Those variables significant at p<0.01 were assigned an integer score proportional to the regression coefficient. The model was then validated in the derivation cohort and a separate validation cohort. Patients were then split into three risk categories, and rates of recurrence were described for each category. The CDI recurrence prediction rule included the following predictor variables with their respective point values: prior third- and fourth-generation cephalosporins (1 point), prior proton pump inhibitors (1 point), prior antidiarrheals (1 point), nonsevere CDI (2 points), and community-onset CDI (3 points). In the derivation cohort, the 60-day CDI recurrence risk for each score ranged from 7.5% (0 points) to 57.9% (8 points). The risk score was strongly correlated with recurrence (R²  = 0.94). Patients were split into low-risk (0-2 points), medium-risk (3-5 points), and high-risk (6-8 points) classes and had the following recurrence rates: 8.9%, 20.2%, and 35.0%, respectively. Findings were similar in the validation cohort.

CONCLUSION

Several CDI and patient-specific factors were independently associated with 60-day CDI recurrence risk. When integrated into a clinical prediction rule, higher risk scores and risk classes were strongly correlated with CDI recurrence. This clinical prediction rule can be used by providers to identify patients at high risk for CDI recurrence and help guide preventive strategy decisions, while accounting for clinical judgment.

Genomic and phenotypic diversity of Clostridium difficile during long-term sequential recurrences of infection

Infection with the emerging pathogen Clostridioides (Clostridium) difficile might lead to colonization of the gastrointestinal tract of humans and mammals eventually resulting in antibiotic-associated diarrhea, which can be mild to possibly life-threatening. Recurrences after antibiotic treatment have been described in 15-30% of the cases and are either caused by the original (relapse) or by new strains (reinfection). In this study, we describe a patient with ongoing recurrent C. difficile infections over 13 months. During this time, ten C. difficile strains of six different ribotypes could be isolated that were further characterized by phenotypic and genomic analyses including motility and sporulation assays, growth fitness and antibiotic susceptibility as well as whole-genome sequencing. PCR ribotyping of the isolates confirmed that the recurrences were a mixture of relapses and reinfections. One recurrence was due to a mixed infection with three different strains of two different ribotypes. Furthermore, genomes were sequenced and multi-locus sequence typing (MLST) was carried out, which identified the strains as members of sequence types (STs) 10, 11, 14 and 76. Comparison of the genomes of isolates of the same ST originating from recurrent CDI (relapses) indicated little within-patient microevolution and some concurrent within-patient diversity of closely related strains. Isolates of ribotype 126 that are binary toxin positive differed from other ribotypes in various phenotypic aspects including motility, sporulation behavior and cell morphology. Ribotype 126 is genetically related to ribotype 078 that has been associated with increased virulence. Isolates of the ribotype 126 exhibited elongated cells and a chaining phenotype, which was confirmed by membrane staining and scanning electron microscopy. Furthermore, this strain exhibits a sinking behavior in liquid medium in stationary growth phase. Taken together, our observation has proven multiple CDI recurrences that were based on a mixture of relapses and reinfections.

Nosocomial-acquired and community-onset Clostridium difficile infection at an academic hospital in Italy: Epidemiology, recurrences and toxin genes distribution

Toxinogenic Clostridium difficile infection (CDI) is a leading cause of infectious diarrhea. In this retrospective cohort study the molecular epidemiology of hospital-acquired and community-associated CDI was investigated in patients admitted to a tertiary care hospital. CD in stools samples was revealed by a two steps diagnostic algorithm, firstly screening for positivity to GDH antigen and thereafter RT-PCR analysis. Increased CDI incidence was observed ranging from 1.70episodes/10000patient-days in the 1st year, to 2.62 in the 2nd year, mostly hospitalized in the medicine wards, followed by outpatients (5.74 and 5.12episodes/10.000patient-days respectively). CDI positive were older than CDI negative patients and presented increased trend of diarrhea episodes as the patients' age increased. RT-PCR positive patients (n° = 314) were classified according to the CD toxin producing genes in three groups (1-3, carrying tcdB, both tcdB and cdt, and the two genes plus the deletion Δ117 of tcdC, respectively). The incidence of the group 2 and 3 increased statistically with the age of the patients showing correlation with the gender. Higher frequency of patients belonging to group 1 and group 3 was observed in the medical wards. Of note was the high incidence of group 3 in outpatients. Interestingly, patients with previous health care contacts had higher risk (RR = 1.88) of being infected by CD strains with higher toxicity than community patients. Recurrence rate was 15.9%. In conclusion the knowledge of the toxigenic profiles and of their relationships to gender, age and wards distribution may help the clinicians in the clinical management of the disease.

Stability and efficacy of frozen and lyophilized fecal microbiota transplant (FMT) product in a mouse model of Clostridium difficile infection (CDI)

Freezing donor fecal microbiota has simplified fecal microbiota transplantation (FMT) in the treatment of recurrent C. difficile infection (CDI). However, the optimal storage time for the frozen FMT products remains unknown. Using an established murine model of CDI, stability and efficacy of frozen and lyophilized FMT product was studied at time points from 2 months to 15 months. DNA was extracted from fecal samples from the mice with identification of specific bacterial species by real-time quantitative PCR (qPCR). FMT product stability and efficacy were measured by occurrence of diarrhea in the challenged mice together with stability of the microbiota composition. The results were analyzed and compared by SAS statistical software. All mice treated with only C. difficile developed diarrhea within 72 h. Mice treated with frozen (n = 5/group), lyophilized (n = 5/group) products stored for ≤ 7-month or fresh FMT product (n = 22) were protected from post C. difficile challenge diarrhea. There was no difference between frozen and lyophilized products (n = 5/group) stored for ≤ 7 months 95% CI 1.00 (0.38-2.64) and 1.00 (0.38-2.64), respectively. Prevention if CDI by frozen and lyophilized product was not different for storage of 9-, 11- and 15-months. qPCR results demonstrated there were no significant quantitative change in Bacteroides and Clostridium species during any of the storage times (P > 0.05). In the present study, frozen and lyophilized FMT products were stored up to 7 months without losing microbiota composition and therapeutic efficacy. The animal model described may be useful to study stability of human microbiota designed for FMT.