A Randomized, Placebo-controlled Trial of Fidaxomicin for Prophylaxis of Clostridium difficile-associated Diarrhea in Adults Undergoing Hematopoietic Stem Cell Transplantation

Management of Clostridioides difficile infection: an Italian Delphi consensus

BACKGROUND

Clostridioides difficile infection (CDI), a leading cause of nosocomial deaths, is a microbiota-mediated disease. As such, the use of broader spectrum antibiotics, such as vancomycin and metronidazole, can prime the gastrointestinal tract to become more prone to CDI recurrences. Fidaxomicin, a narrow-spectrum antibiotic, has been demonstrated to be superior in preventing recurrence and in preserving the intestinal microbiota; however, widespread employment worldwide has been hindered due to high acquisition costs.

OBJECTIVES

To integrate the currently available guidelines on the management of CDI and to shed light on the timeliest employment of fidaxomicin.

METHODS

An expert panel was gathered to obtain consensus using Delphi methodology on a series of statements regarding the management of CDI and on appropriate antibiotic use.

RESULTS

Consensus was reached on 21 of the 25 statements addressing the management of CDI.

CONCLUSIONS

Delphi methodology was used to achieve consensus on the management of CDI, on the identification of patients at risk of recurrences or severe infection, and on the most appropriate use of fidaxomicin, with the final aim of fostering clinical practice application of treatment algorithms proposed by previous guidelines, in absolute synergy. It could be an important tool to promote more appropriate and cost-effective CDI treatments in European settings with limited resources, like Italy.

Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

An Open-Label, Randomized Trial Comparing Fidaxomicin With Oral Vancomycin for the Treatment of Clostridioides difficile Infection in Hospitalized Patients Receiving Concomitant Antibiotics for Concurrent Infections

BACKGROUND

Recurrent Clostridioides difficile infection (rCDI) occurs frequently, and concomitant antibiotic (CA) during the initial episode for treatment of non-CDI is a major risk factor. We sought to address the comparative efficacy of fidaxomicin versus vancomycin in the setting of CA during the initial CDI episode.

METHODS

We conducted a randomized, controlled, open-label trial at 2 hospitals in Ann Arbor, Michigan. We consecutively consented and enrolled hospitalized patients ≥18 years old with diarrhea, a positive test for C. difficile, and ≥1 qualifying CA. Complicated CDI, CDI treatment for >24 hours prior to enrollment, and planned long-term (>12 weeks) CA use were notable exclusions. Clinical cure was defined as resolution of diarrhea for 2 consecutive days maintained until 2 days after therapy, and rCDI as recurrent diarrhea with positive testing ≤30 days after initial treatment. Patients were randomized to fidaxomicin or vancomycin.

RESULTS

Baseline characteristics were similar in the 2 groups of 144 patients. Rates of clinical cure (73% vs 62.9%, P = .195) and rCDI (3.3% vs 4.0%; P > .99) were similar for fidaxomicin and vancomycin in the intention-to-treat and per-protocol cohorts, respectively. Only 4 patients developed rCDI.

CONCLUSIONS

In this study of patients with CDI receiving CA, a numerically higher proportion were cured with fidaxomicin versus vancomycin, but this result did not reach statistical significance. Overall recurrence was lower than anticipated in both arms compared with previous studies that did not extend duration of CDI treatment during CA.

CLINICAL TRIALS REGISTRATION

www.clinicaltrials.gov (NCT02692651).

Prevention and treatment of C. difficile in cancer patients

PURPOSE OF REVIEW

We provide an update on the recent literature on Clostridioides difficile infection (CDI) in cancer patients.

RECENT FINDINGS

Distinguishing between colonization and infection remains challenging in cancer patients. Many patients with negative toxin analysis are still treated for CDI, and some meet criteria for severe cases. The incidence of CDI is high in cancer patients, especially those with haematological malignancies. Disruption of the gut microbiome due to antibiotic consumption, chemotherapy and radiotherapy is the primary factor contributing to CDI development. The severity of CDI in cancer patients is often unclear due to the absence of well-defined severity criteria. Certain microbiome species predominance and specific ribotypes have been associated with worse outcomes. Whole genome sequencing could be helpful for differentiating recurrence from reinfection and exploring potential nosocomial transmission. While certain new drugs such as fidaxomicin or bezlotoxumab show promise, the optimal treatment and prevention strategies for CDI in cancer patients remain uncertain. Faecal microbiota transplantation (FMT) holds potential for reducing CDI recurrence rates.

SUMMARY

Further studies are needed to provide robust recommendations for diagnosis, grading severity, and therapeutic management of CDI in cancer patients. Recurrences are particularly concerning due to subsequent exposition to CDI risk factors.

Clostridioides difficile infection in the allogeneic hematopoietic cell transplant recipient

Clostridioides difficile (CD) is one of the most important causes of diarrhea in hospitalized patients, in particular those who undergo an allogeneic hematopoietic cell transplant (allo-HCT) and who are more at risk of developing a CD infection (CDI) due to frequent hospitalizations, iatrogenic immunosuppression, and prolonged antibiotic cycles. CDI may represent a severe condition in allo-HCT patients, increasing the length of hospitalization, influencing the intestinal microbiome with a bidirectional association with graft-versus-host disease, and leading to unfavorable outcomes, including death. The diagnosis of CDI requires the exclusion of other probable causes of diarrhea in HCT patients and is based on highly sensitive and highly specific tests to distinguish colonization from infection. In adult patients, fidaxomicin is recommended as first-line, with oral vancomycin as an alternative agent. Bezlotoxumab may be used to reduce the risk of recurrence. In pediatric patients, vancomycin and metronidazole are still suggested as first-line therapy, but fidaxomicin will probably become standard in pediatrics in the near future. Because of insufficient safety data, fecal microbiota transplantation is not routinely recommended in HCT in spite of promising results for the management of recurrences in other populations.

Longitudinal genomic surveillance of carriage and transmission of Clostridioides difficile in an intensive care unit

Despite enhanced infection prevention efforts, Clostridioides difficile remains the leading cause of healthcare-associated infections in the United States. Current prevention strategies are limited by their failure to account for patients who carry C. difficile asymptomatically, who may act as hidden reservoirs transmitting infections to other patients. To improve the understanding of asymptomatic carriers' contribution to C. difficile spread, we conducted admission and daily longitudinal culture-based screening for C. difficile in a US-based intensive care unit over nine months and performed whole-genome sequencing on all recovered isolates. Despite a high burden of carriage, with 9.3% of admissions having toxigenic C. difficile detected in at least one sample, only 1% of patients culturing negative on admission to the unit acquired C. difficile via cross-transmission. While patients who carried toxigenic C. difficile on admission posed minimal risk to others, they themselves had a 24-times greater risk for developing a healthcare-onset C. difficile infection than noncarriers. Together, these findings suggest that current infection prevention practices can be effective in preventing nosocomial cross-transmission of C. difficile, and that decreasing C. difficile infections in hospitals further will require interventions targeting the transition from asymptomatic carriage to infection.

Microbiome-Related and Infection Control Approaches to Primary and Secondary Prevention of Clostridioides difficile Infections

Clostridioides difficile infections (CDIs) have decreased in the past years, but since 2021, some hospitals have reported an increase in CDI rates. CDI remains a global concern and has been identified as an urgent threat to healthcare. Although multiple treatment options are available, prevention strategies are more limited. As CDI is an opportunistic infection that arises after the normally protective microbiome has been disrupted, preventive measures aimed at restoring the microbiome have been tested. Our aim is to update the present knowledge on these various preventive strategies published in the past five years (2018-2023) to guide clinicians and healthcare systems on how to best prevent CDI. A literature search was conducted using databases (PubMed, Google Scholar, and clinicaltrials.gov) for phase 2-3 clinical trials for the primary or secondary prevention of CDI and microbiome and probiotics. As the main factor for Clostridium difficile infections is the disruption of the normally protective intestinal microbiome, strategies aimed at restoring the microbiome seem most rational. Some strains of probiotics, the use of fecal microbial therapy, and live biotherapeutic products offer promise to fill this niche; although, more large randomized controlled trials are needed that document the shifts in the microbiome population.

The incidence and impact of clostridioides difficile infection on transplant outcomes in acute leukemia and MDS after allogeneic hematopoietic cell transplant-a CIBMTR study

Clostridioides difficile infection (CDI) is common after allogeneic hematopoietic cell transplantation (alloHCT). The determination of incidence, risk factors, and impact of CDI on alloHCT outcomes is an unmet need. The study examines all patients aged 2 years and older who received first alloHCT for acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), or myelodysplastic syndrome (MDS) between 2013 and 2018 at US centers and reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) data registry. In total, 826 patients with CDI and 6723 controls from 127 centers were analyzed. The cumulative incidence of CDI by day 100 was 18.7% (99% CI: 15-22.7%) and 10.2% (99% CI: 9.2-11.1%) in pediatric and adult patients, respectively, with a median time to diagnosis at day +13. CDI was associated with inferior overall survival (OS) (p = 0.0018) and a 2.58-fold [99% CI: 1.43-4.66; p < 0.001] increase in infection-related mortality (IRM). There was a significant overlap in the onset of acute graft versus host disease (aGVHD) and CDI. IRM increased to >4 fold when CDI + aGVHD was considered. Despite advances in the management of CDI, increased IRM and decreased OS still results from CDI.

Predicted Bezlotoxumab Exposure in Patients Who Have Received a Hematopoietic Stem Cell Transplant

PURPOSE

Bezlotoxumab is approved for prevention of recurrent Clostridioides (Clostridium) difficile infection (CDI) in adults receiving antibacterial treatment for CDI who are at high risk for recurrent CDI. Previous studies have shown that although serum albumin levels are an important predictor for bezlotoxumab exposure, this has no clinically meaningful impact on efficacy. This pharmacokinetic modeling study assessed whether hematopoietic stem cell transplant (HSCT) recipients, at increased risk of CDI and exhibiting decreased albumin levels within the first month posttransplant, are at risk of clinically relevant reductions in bezlotoxumab exposure.

METHODS

Observed bezlotoxumab concentration-time data pooled from participants in Phase III trials MODIFY I and II (ClinicalTrials.gov identifiers NCT01241552/NCT01513239) and three Phase I studies (PN004, PN005, and PN006) were used to predict bezlotoxumab exposures in two adult post-HSCT populations: A Phase Ib study of posaconazole including allogeneic HSCT recipients (ClinicalTrials.gov identifier NCT01777763; posaconazole-HSCT population); and a Phase III study of fidaxomicin for CDI prophylaxis (ClinicalTrials.gov identifier NCT01691248; fidaxomicin-HSCT population). The bezlotoxumab PK model used the minimum albumin level for each individual in post-HSCT populations to mimic a "worst-case scenario."

FINDINGS

Predicted worst-case bezlotoxumab exposures for the posaconazole-HSCT population (N = 87) were decreased by 10.8% versus bezlotoxumab exposures observed in the pooled Phase III/Phase I data set (N = 1587). No further decrease was predicted for the fidaxomicin-HSCT population (N = 350).

IMPLICATIONS

Based on published population pharmacokinetic data, the predicted decrease in bezlotoxumab exposure in the post-HSCT populations is not expected to have a clinically meaningful effect on bezlotoxumab efficacy at the recommended 10 mg/kg dose. Dose modification is therefore not required in the hypoalbuminemia setting expected post-HSCT. (Clin Ther. 2023;45:XXX-XXX) © 2023 Elsevier HS Journals, Inc.

Controversies in the Prevention and Treatment of Clostridioides difficile Infection in Adults: A Narrative Review

Clostridioides difficile remains a problematic pathogen resulting in significant morbidity and mortality, especially for high-risk groups that include immunocompromised patients. Both the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America (IDSA/SHEA), as well as the American College of Gastroenterology (ACG) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) recently provided guideline updates for C. difficile infection (CDI). In this narrative review, the authors reviewed available literature regarding the prevention or treatment of CDI in adults and focused on disagreements between the IDSA/SHEA and ACG guidelines, as well as articles that have been published since the updates. Several options for primary prophylaxis are available, including probiotics and antibiotics (vancomycin, fidaxomicin). The literature supporting fidaxomicin is currently quite limited. While there are more studies evaluating probiotics and vancomycin, the optimal patient populations and regimens for their use have yet to be defined. While the IDSA/SHEA guidelines discourage metronidazole use for mild CDI episodes, evidence exists that it may remain a reasonable option for these patients. Fidaxomicin has an advantage over vancomycin in reducing recurrences, but its use is limited by cost. Despite this, recent studies suggest fidaxomicin's cost-effectiveness as a first-line therapy, though this is highly dependent on institutional contracts and payment structures. Secondary prophylaxis should focus on non-antimicrobial options to lessen the impact on the microbiome. The oral option of fecal microbiota transplantation (FMT), SER109, and the now FDA-approved RBX2660 represent exciting new options to correct dysbiosis. Bezlotoxumab is another attractive option to prevent recurrences. Further head-to-head studies of newer agents will be needed to guide selection of the optimal therapies for CDI primary and secondary prophylaxis.

American Society for Transplantation and Cellular Therapy Series: #5-Management of Clostridioides difficile Infection in Hematopoietic Cell Transplant Recipients

The Practice Guidelines Committee of the American Society for Transplantation and Cellular Therapy partnered with its Transplant Infectious Disease Special Interest Group to update its 2009 compendium-style infectious disease guidelines for hematopoietic cell transplantation (HCT). A completely new approach was taken with the goal of better serving clinical providers by publishing each standalone topic in the infectious disease series as a concise format of frequently asked questions (FAQ), tables, and figures. Adult and pediatric infectious disease and HCT content experts developed and then answered FAQs and finalized topics with harmonized recommendations that were made by assigning an A through E strength of recommendation paired with a level of supporting evidence graded I through III. This fifth guideline in the series focuses on Clostridioides difficile infection with FAQs that address the prevalence, incidence, clinical features, colonization versus infection, clinical complications, diagnostic considerations, pharmacological therapies for episodic or recurrent infection, and the roles of prophylactic antibiotics, probiotics, and fecal microbiota transplantation.

Prevalence of Clostridium difficile Infection in the Hematopoietic Transplantation Setting: Update of Systematic Review and Meta-Analysis

Hematopoietic stem cell transplant (HSCT) recipients are vulnerable to Clostridium difficile infection (CDI) due to risk factors such as immunosuppression, antimicrobial use, and frequent hospitalization. We systematically searched PubMed and Embase to screen relevant studies from April 2014 to November 2021. A meta-analysis was performed to identify the association between CDI and hematopoietic transplantation based on the standard mean difference and 95% confidence intervals (CIs). Among the 431 retrieved citations, we obtained 43 eligible articles, which included 15,911 HSCT patients at risk. The overall estimated prevalence of CDI was 13.2%. The prevalence of CDI among the 10,685 allogeneic transplantation patients (15.3%) was significantly higher than that among the 3,840 autologous HSCT recipients (9.2%). Different incidence rates of CDI diagnosis over the last 7 years were found worldwide, of which North America (14.1%) was significantly higher than Europe (10.7%) but not significantly different from the prevalence among Asia (11.6%). Notably, we found that the estimated prevalence of CDI diagnosed by polymerase chain reaction (PCR) (17.7%) was significantly higher than that diagnosed by enzyme immunoassay (11.5%), indicating a significant discrepancy in the incidence rate of CDI owing to differences in the sensibility and specificity of the detection methods. Recurrence of CDI was found in approximately 15% of the initial patients with CDI. Furthermore, 20.3% of CDI cases were severe. CDI was found to be a common complication among HSCT recipients, displaying an evident increase in the morbidity of infection.

Oral Vancomycin Prophylaxis for Primary and Secondary Prevention of Clostridioides difficile Infection in Patients Treated with Systemic Antibiotic Therapy: A Systematic Review, Meta-Analysis and Trial Sequential Analysis

Background: Clostridioides difficile infection (CDI) is associated with substantial morbidity and mortality as well as high propensity of recurrence. Systemic antibiotic therapy (SAT) represents the top inciting factor of CDI, both primary and recurrent (rCDI). Among the many strategies aimed to prevent CDI in high-risk subjects undergoing SAT, oral vancomycin prophylaxis (OVP) appears promising under a cost-effectiveness perspective. Methods: A systematic review with meta-analysis and trial sequential analysis (TSA) of studies assessing the efficacy and the safety of OVP to prevent primary CDI and rCDI in persons undergoing SAT was carried out. PubMed and EMBASE were searched until 30 September 2021. The protocol was pre-registered on PROSPERO (CRD42019145543). Results: Eleven studies met the inclusion criteria, only one being a randomized controlled trial (RCT). Overall, 929 subjects received OVP and 2011 represented the comparator group (no active prophylaxis). OVP exerted a strong protective effect for CDI occurrence: odds ratio 0.14, 95% confidence interval 0.04–0.38. Moderate heterogeneity was observed: I² 54%. This effect was confirmed throughout several subgroup analyses, including prevention of primary CDI versus rCDI. TSA results pointed at the conclusive nature of the evidence. Results were robust to a variety of sensitivity and quantitative bias analyses, although the underlying evidence was deemed as low quality. No differences between the two groups were highlighted regarding the onset of vancomycin-resistant Enterococcus infections. Conclusions: OVP appears to be an efficacious option for prevention of CDI in high-risk subjects undergoing SAT. Nevertheless, additional data from RCTs are needed to establish OVP as good clinical practice and define optimal dosage and duration.

European Society of Clinical Microbiology and Infectious Diseases: 2021 update on the treatment guidance document for Clostridioides difficile infection in adults

SCOPE

In 2009, the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) published the first treatment guidance document for Clostridioides difficile infection (CDI). This document was updated in 2014. The growing literature on CDI antimicrobial treatment and novel treatment approaches, such as faecal microbiota transplantation (FMT) and toxin-binding monoclonal antibodies, prompted the ESCMID study group on C. difficile (ESGCD) to update the 2014 treatment guidance document for CDI in adults.

METHODS AND QUESTIONS

Key questions on CDI treatment were formulated by the guideline committee and included: What is the best treatment for initial, severe, severe-complicated, refractory, recurrent and multiple recurrent CDI? What is the best treatment when no oral therapy is possible? Can prognostic factors identify patients at risk for severe and recurrent CDI and is there a place for CDI prophylaxis? Outcome measures for treatment strategy were: clinical cure, recurrence and sustained cure. For studies on surgical interventions and severe-complicated CDI the outcome was mortality. Appraisal of available literature and drafting of recommendations was performed by the guideline drafting group. The total body of evidence for the recommendations on CDI treatment consists of the literature described in the previous guidelines, supplemented with a systematic literature search on randomized clinical trials and observational studies from 2012 and onwards. The Grades of Recommendation Assessment, Development and Evaluation (GRADE) system was used to grade the strength of our recommendations and the quality of the evidence. The guideline committee was invited to comment on the recommendations. The guideline draft was sent to external experts and a patients' representative for review. Full ESCMID endorsement was obtained after a public consultation procedure.

RECOMMENDATIONS

Important changes compared with previous guideline include but are not limited to: metronidazole is no longer recommended for treatment of CDI when fidaxomicin or vancomycin are available, fidaxomicin is the preferred agent for treatment of initial CDI and the first recurrence of CDI when available and feasible, FMT or bezlotoxumab in addition to standard of care antibiotics (SoC) are preferred for treatment of a second or further recurrence of CDI, bezlotoxumab in addition to SoC is recommended for the first recurrence of CDI when fidaxomicin was used to manage the initial CDI episode, and bezlotoxumab is considered as an ancillary treatment to vancomycin for a CDI episode with high risk of recurrence when fidaxomicin is not available. Contrary to the previous guideline, in the current guideline emphasis is placed on risk for recurrence as a factor that determines treatment strategy for the individual patient, rather than the disease severity.

How to: prophylactic interventions for prevention of Clostridioides difficile infection

BACKGROUND

Clostridioides difficile infection (CDI) remains the leading cause of healthcare-associated diarrhoea, despite existing guidelines for infection control measures and antimicrobial stewardship. The high associated health and economic burden of CDI calls for novel strategies to prevent the development and spread of CDI in susceptible patients.

OBJECTIVES

We aim to review CDI prophylactic treatment strategies and their implementation in clinical practice.

SOURCES

We searched PubMed, Embase, Emcare, Web of Science, and the COCHRANE Library databases to identify prophylactic interventions aimed at prevention of CDI. The search was restricted to articles published in English since 2012.

CONTENT

A toxin-based vaccine candidate is currently being investigated in a phase III clinical trial. However, a recent attempt to develop a toxin-based vaccine has failed. Conventional probiotics have not yet proved to be an effective strategy for prevention of CDI. New promising microbiota-based interventions that bind and inactivate concomitantly administered antibiotics, such as ribaxamase and DAV-132, have been developed. Prophylaxis of CDI with C. difficile antibiotics should not be performed routinely and should be considered only for secondary prophylaxis in very selected patients who are at the highest imminent risk for recurrent CDI (R-CDI) after a thorough evaluation. Faecal microbiota transplantation (FMT) has proved to be a very effective treatment for patients with multiple recurrences. Bezlotoxumab provides protection against R-CDI, mainly in patients with primary episodes and a high risk of relapse.

IMPLICATIONS

There are no proven effective, evidenced-based prophylaxis options for primary CDI. As for secondary prevention, FMT is considered the option of choice in patients with multiple recurrences. Bezlotoxumab can be added to standard treatment for patients at high risk for R-CDI. The most promising strategies are those aimed at reducing changes in intestinal microbiota and development of a new effective non-toxin-based vaccine.

ACG Clinical Guidelines: Prevention, Diagnosis, and Treatment of Clostridioides difficile Infections

Clostridioides difficile infection occurs when the bacterium produces toxin that causes diarrhea and inflammation of the colon. These guidelines indicate the preferred approach to the management of adults with C. difficile infection and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation process. In instances where the evidence was not appropriate for Grading of Recommendations Assessment, Development, and Evaluation but there was consensus of significant clinical merit, key concept statements were developed using expert consensus. These guidelines are meant to be broadly applicable and should be viewed as the preferred, but not the only, approach to clinical scenarios.

Infectious Gastroenteritis in Transplant Patients

Infectious gastroenteritis is common after transplantation and can lead to increased morbidity and mortality. A wide range of organisms can lead to gastroenteritis in this patient population. Clostridioides difficile, cytomegalovirus, and norovirus are the most common pathogens. Newer diagnostic methods, especially multiplex polymerase chain reaction, have increased the diagnostic yield of infectious etiologies. In this review, we describe the epidemiology and risk factors for common infectious pathogens leading to gastroenteritis.

Clostridioides difficile Infection and Risk of Acute Graft-versus-Host Disease among Allogeneic Hematopoietic Stem Cell Transplantation Recipients

Clostridioides difficile infection (CDI) is a major cause of infectious diarrhea among allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. The relationship between CDI and acute graft-versus-host disease (aGVHD) has been a topic of interest, as these 2 conditions may influence each other. We studied the temporal relationship of CDI to aGVHD in the first 100 days post-transplantation in a large cohort of allo-HSCT recipients. We performed a retrospective cohort study of adult patients undergoing their first allo-HSCT at our tertiary care medical center between January 1, 2010, and December 31, 2016. Patients were followed for CDI diagnosis, development of aGVHD, and vital status up to day +100 post-transplantation. Descriptive statistics and multivariate Cox models with CDI as a time-varying covariate and aGVHD and high-grade aGVHD as outcomes were used for data analyses. A total of 656 allo-HSCT recipients were included in the analysis. Of these, 419 (64%) developed aGVHD, and 111 (17%) were diagnosed with CDI within the first 100 days post-transplantation. CDI developed before the onset of aGVHD in 72 of the 84 allo-HSCT recipients (85%) with both CDI and aGVHD. Fidaxomicin was used in the treatment of 57 of the 111 CDI cases (50%), whereas vancomycin was used in 52 (47%). Most of the CDI cases (88%) were diagnosed in the peritransplantation period (between day -10 and day +10). The median time to the development of CDI and aGVHD was 3.5 days (range, -7 to 95 days) and 33 days (range, 9 to 98 days) post-transplantation, respectively. Using multivariate Cox model, the following predictors were significantly associated with the development of aGVHD: CDI (adjusted hazard ratio [aHR], 1.52; 95% confidence interval [CI], 1.17 to 1.97; P = .0018), transplantation from a matched related donor (MRD) compared with a matched unrelated donor (aHR, 0.68; 95% CI, 0.54 to 0.85; P = .0003), and myeloablative versus nonmyeloablative conditioning (aHR, 2.45; 95% CI, 1.80 to 3.34; P < .0001), adjusting for age, sex, race, underlying disease, cytomegalovirus CMV serostatus, transplant source, and receipt of antithymocyte globulin (ATG). There was no association between CDI and high-grade aGVHD after adjustment for age, underlying disease, transplant type, intensity of conditioning, and receipt of ATG (aHR, 1.59; 95% CI, 0.95 to 2.66; P = .0755). CDI after allo-HSCT is associated with increased risk of GVHD when no CDI prophylaxis was used. Further studies examining CDI preventive measures, including prophylaxis, as well as the preservation or reconstitution of the gastrointestinal microbiome in the setting of HSCT are warranted.

Prophylaxis, diagnosis and therapy of infections in patients undergoing high-dose chemotherapy and autologous haematopoietic stem cell transplantation. 2020 update of the recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

To ensure the safety of high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT), evidence-based recommendations on infectious complications after HDC/ASCT are given. This guideline not only focuses on patients with haematological malignancies but also addresses the specifics of HDC/ASCT patients with solid tumours or autoimmune disorders. In addition to HBV and HCV, HEV screening is nowadays mandatory prior to ASCT. For patients with HBs antigen and/or anti-HBc antibody positivity, HBV nucleic acid testing is strongly recommended for 6 months after HDC/ASCT or for the duration of a respective maintenance therapy. Prevention of VZV reactivation by vaccination is strongly recommended. Cotrimoxazole for the prevention of Pneumocystis jirovecii is supported. Invasive fungal diseases are less frequent after HDC/ASCT, therefore, primary systemic antifungal prophylaxis is not recommended. Data do not support a benefit of protective room ventilation e.g. HEPA filtration. Thus, AGIHO only supports this technique with marginal strength. Fluoroquinolone prophylaxis is recommended to prevent bacterial infections, although a survival advantage has not been demonstrated.

Utilizing antibiotics to prevent Clostridioides difficile infection: does exposure to a risk factor decrease risk? A systematic review

BACKGROUND

Antibiotic use is a major risk factor for Clostridioides difficile infection (CDI). However, antibiotics recommended for CDI treatment are being utilized in clinical practice as prophylactic agents.

OBJECTIVES

To comprehensively summarize and critically evaluate the published literature investigating the effectiveness of antibiotic CDI prophylaxis.

METHODS

A systematic search for relevant literature was conducted in PubMed and ClinicalTrials.gov. Two investigators independently screened each article for inclusion, and the references of the included articles were studied to identify additional relevant articles. Data extraction and an assessment of risk of bias was completed for all included studies. Unadjusted risk ratios and 95% CI were calculated for each study, with CDI being the outcome variable and prophylaxis (prophylaxis versus control) representing the exposure.

RESULTS

In total, 13 articles were identified in PubMed and 9 ongoing or unpublished trials were identified in ClinicalTrials.gov. The effect of antibiotic prophylaxis on CDI rates varied between studies; however, most favoured the use of antibiotic prophylaxis.

CONCLUSIONS

The authors of this review conclude that the current literature carries a high risk of bias and the results should be interpreted with caution.

Prospective assessment of Clostridioides (formerly Clostridium) difficile colonization and acquisition in hematopoietic stem cell transplant patients

BACKGROUND

Patients undergoing hematopoietic stem cell transplant (HSCT) possess numerous risk factors for Clostridioides (formerly Clostridium) difficile infection (CDI) and experience a high rate of diarrhea. Colonization rates of Clostridium difficile vary greatly among subgroup analyses with recent studies demonstrating colonization rates in the blood and marrow transplant units up to nine times that of the general population.

METHODS

The primary objectives of this study were to identify the rate of C difficile colonization and acquisition in HSCT patients admitted to the blood and marrow transplant unit. This was a prospective study that included all adult patients admitted for hematopoietic stem cell transplantation. Stool specimens were routinely collected on admission and weekly thereafter for a maximum of six samples per patient.

RESULTS

Forty-two patients met inclusion criteria and had baseline samples available for analysis. The rate of C difficile colonization on admission was 24%, and an additional 9% of patients acquired the organism during admission. Twelve percent of patients developed CDI that was diagnosed clinically. Univariate analysis showed an increased risk of colonization for patients with three or more prior chemotherapy cycles.

CONCLUSIONS

Given high colonization rates coupled with high risk of CDI in this population, providers must be judicious when testing for CDI and interpreting test results for HSCT patients.

Clostridioides difficile in transplant patients: early diagnosis, treatment, and prevention

PURPOSE OF REVIEW

Clostridioides difficile infection is common in solid organ transplant and hematopoietic stem-cell transplant recipients and is associated with significant morbidity and mortality. These populations are also underrepresented in clinical trials, making optimal management difficult. Because of this, management of these populations follows national guideline recommendations. This review aims to summarize the recent relevant literature pertaining to the clinical management of C. difficile infection in transplant patients, with a particular focus on diagnosis, treatment, and prevention.

RECENT FINDINGS

Early diagnosis of C. difficile colonization may mitigate both horizontal and vertical transmission (progression from colonization to colitis) of infection. Once diagnosed, recent literature suggests antibiotic treatment should align with that recommended by national guidelines. Fecal microbiota transplant is an emerging therapy for recurrent C. difficile infection, and recent data have demonstrated safety and efficacy. Prevention strategies including antimicrobial stewardship, probiotic administration, antibiotic administration, and bezlotoxumab may be beneficial in transplant populations, but more data are needed to confirm recent findings.

SUMMARY

Studies evaluating C. difficile infection in transplant patients are only recently starting to emerge. Further research is needed to identify optimal treatment and prevention strategies, and to examine novel strategies such as microbiome manipulation.

Clostridium difficile infection in a children's hospital with specific patterns among pediatric oncology and hematopoietic stem cell transplantation populations

Background: Clostridium difficile (CD) is often classified as a healthcare-associated infection (HAI) and a hospital-acquired condition (HAC) in the hospital setting. However, pediatric oncology patients comprise a significant portion of Clostridium difficile infections (CDI), with hematopoietic stem cell transplant (HSCT) recipients constituting a major subset of this group due to unique, non-modifiable risk factors. We evaluated patterns of clostridium difficile infections at our institution to provide an accurate evaluation of the vulnerability of pediatric oncology and HSCT patients to clostridium difficile infections in comparison to the general pediatric population and underscore the non-tenability of classifying clostridium difficile infections as a hospital-acquired condition in HSCT patients. Methods: Single-center retrospective review of all clostridium difficile stool tests performed over an 11-year period; data analyzed and statistical comparisons performed between patient groups. Results: 5271 total samples were obtained during the study time period from 3127 patients. At least one positive test result was found in 18.6% of patients. Oncology and HSCT patients (38.2%) were more likely to have a positive test result than hematology (17.5%) and other patients (16.8%) (p < 0.001). Sixty-percent of patients who underwent HSCT were tested during this time frame. Of those, 39.3% had a positive test result and 48.5% of those patients went on to have a subsequent infection that met the criteria to be defined as recurrent. Conclusions: The high incidence rate and frequency of recurrence underscores the current near-inevitable nature of clostridium difficile infections in oncology and HSCT patients. We conclude that a blanket designation of clostridium difficile infections as an hospital-acquired condition is therefore questionable in this population.

Make Sure You Have a Safety Net: Updates in the Prevention and Management of Infectious Complications in Stem Cell Transplant Recipients

Hematopoietic stem cell transplant recipients are at increased risk of infection and immune dysregulation due to reception of cytotoxic chemotherapy; development of graft versus host disease, which necessitates treatment with immunosuppressive medications; and placement of invasive catheters. The prevention and management of infections in these vulnerable hosts is of utmost importance and a key “safety net” in stem cell transplantation. In this review, we provide updates on the prevention and management of CMV infection; invasive fungal infections; bacterial infections; Clostridium difficile infection; and EBV, HHV-6, adenovirus and BK infections. We discuss novel drugs, such as letermovir, isavuconazole, meropenem-vaborbactam and bezlotoxumab; weigh the pros and cons of using fluoroquinolone prophylaxis during neutropenia after stem cell transplantation; and provide updates on important viral infections after hematopoietic stem cell transplant (HSCT). Optimizing the prevention and management of infectious diseases by using the best available evidence will contribute to better outcomes for stem cell transplant recipients, and provide the best possible “safety net” for these immunocompromised hosts.

Recent developments in the management of recurrent Clostridioides difficile infection

Clostridioides (formerly Clostridium) difficile is responsible for a substantial burden of nosocomial infection. Recurrent C. difficile infection (rCDI) remains a concern due to its high morbidity, mortality, and cost. Despite the updated 2017 IDSA C. difficile treatment guidelines, there remains a lack of well-studied preventive control measures and treatment modalities for rCDI. There are ongoing efforts to develop novel therapies, such as new antibiotics with a lesser impact on gut microbiota and more targeted therapies, such as bacteriotherapy. This mini review highlights key rCDI management updates, preventive measures and ongoing research on novel treatment strategies including bacteriotherapy.

Management of Clostridioides (formerly Clostridium) difficile infection (CDI) in solid organ transplant recipients: Guidelines from the American Society of Transplantation Community of Practice

These updated guidelines from the American Society of Transplantation Infectious Diseases Community of Practice address the prevention and management of Clostridium difficile infection in solid organ transplant (SOT) recipients. Clostridioides (formerly Clostridium) difficile infection (CDI) is among the most common hospital acquired infections. In SOT recipients, the incidence of CDI varies by type and number or organs transplanted. While a meta-analysis of published literature found the prevalence of postoperative CDI in the general surgical population to be approximately 0.51%, the prevalence of CDI that is seen in the solid organ transplant population ranges from a low of 3.2% in the pancreatic transplant population to 12.7% in those receiving multiple organ transplants. There are no randomized, controlled trials evaluating the management of CDI in the SOT population. Herein is a review and summary of the currently available literature that has been synthesized into updated treatment guidelines for the management of CDI in the SOT population.

Clostridioides difficile Infection in the Stem Cell Transplant and Hematologic Malignancy Population

Clostridioides difficile infection (CDI) is common in the stem cell transplant (SCT) and hematologic malignancy (HM) population and mostly occurs in the early posttransplant period. Treatment of CDI in SCT/HM is the same as for the general population, with the exception that fecal microbiota transplant (FMT) has not been widely adopted because of safety concerns. Several case reports, small series, and retrospective studies have shown that FMT is effective and safe. A randomized controlled trial of FMT for prophylaxis of CDI in SCT patients is underway. In addition, an abundance of novel therapeutics for CDI is currently in development.

Oral Vancomycin Prophylaxis Is Highly Effective in Preventing Clostridium difficile Infection in Allogeneic Hematopoietic Cell Transplant Recipients

BACKGROUND

Clostridium difficile infection (CDI) is a leading cause of infectious complications in allogeneic hematopoietic cell transplant recipients (alloHCT). We sought to evaluate whether prophylactic oral vancomycin reduces the incidence of CDI in alloHCT recipients.

METHODS

We conducted a retrospective cohort study to examine the effectiveness of CDI prophylaxis with oral vancomycin, as compared to no prophylaxis, in 145 consecutive adult alloHCT recipients at the University of Pennsylvania between April 2015 and November 2016. Patients received oral vancomycin 125 mg twice daily, starting on admission and continuing until discharge. The primary outcome of interest was the association between oral vancomycin prophylaxis and CDI diagnosis. Secondary outcomes included graft-versus-host disease (GVHD) and relapse.

RESULTS

There were no cases of CDI in patients that received prophylaxis (0/90, 0%), whereas 11/55 (20%) patients who did not receive prophylaxis developed CDI (P < .001). Oral vancomycin prophylaxis was not associated with a higher risk of acute, grades 2-4 GVHD (subhazard ratio [sHR] 1.59; 95% confidence interval [CI] 0.88-2.89; P = .12), acute, grades 3-4 GVHD (sHR 0.65; 95% CI 0.25-1.66; P = .36), or acute, grades 2-4 gastrointestinal GVHD (sHR 1.95; 95% CI 0.93-4.07; P = .08) at day 180 post-transplant. No associations between oral vancomycin and relapse or survival were observed.

CONCLUSIONS

Prophylaxis with oral vancomycin is highly effective in preventing CDI in alloHCT recipients without increasing the risk of graft-versus-host disease or disease relapse. Further evaluation via a prospective study is warranted.

Oral Vancomycin for Secondary Prophylaxis of Clostridium difficile Infection

OBJECTIVE

To summarize and critically appraise the evidence regarding oral vancomycin prophylaxis (OVP) to prevent recurrent Clostridium difficile infections (RCDIs), identify potential consequences of this emerging practice, and highlight future directions of study.

DATA SOURCES

A MEDLINE literature search of English-language publications from 1947 through September 2018 was performed using the search terms vancomycin and C difficile and prophylaxis. Clinical trials were identified on the National Library of Medicine clinical trials registry.

STUDY SELECTION AND DATA EXTRACTION

All clinical studies (n = 3) assessing oral vancomycin for secondary prophylaxis of C difficile infection (CDI) were evaluated by all authors. Other search results and references in selected publications were used for background and discussion.

DATA SYNTHESIS

OVP reduced the risk of RCDI in high-risk patients taking systemic antibiotics. Variable dosing regimens and lack of safety data are limitations. OVP may have an adverse impact on the gastrointestinal microbiome, but this was not examined in the clinical studies. Relevance to Patient Care and Clinical Practice: Although current studies are limited by methodological concerns, clinicians can consider vancomycin 125 mg orally once or twice daily in high-risk patients receiving broad-spectrum antibacterial agents. Results of ongoing trials will define the most appropriate regimen and its impact on outcomes, including collateral damage.

CONCLUSIONS

OVP reduces the risk of RCDIs and should be considered on a case-by-case basis. Caution is warranted before routine use is implemented because the impact on long-term outcomes has not been assessed and the optimal regimen has not been defined.