Epidemiology and outcomes of Clostridium difficile infection in allogeneic hematopoietic cell and lung transplant recipients

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.

Comparison of Clostridioides difficile nucleic acid amplification test (NAAT) results using fresh and frozen stool specimens and rectal swabs

IMPORTANCE

Nucleic acid amplification tests (NAATs) are frequently used in Clostridioides difficile research and diagnostic testing, but the effect of freezing specimens on C. difficile NAAT performance is not well characterized. This study evaluated the concordance of NAAT results between fresh and frozen specimens (fecal and rectal swabs) and found it to be very good to excellent. The results indicate that frozen fecal and rectal swab specimens may be used for C. difficile NAAT testing in research when fresh specimens are not available.

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.

Investigational non-antibiotic therapeutics for infections in hematopoietic cell transplant recipients and patients with hematologic malignancies receiving cellular therapies

In the age of progressive antimicrobial resistance and increased difficulty combating infections in immunocompromised hosts, there has been renewed interest in the use of nontraditional therapeutics for infections. Herein, we review the use of investigational non-pharmaceutical anti-infective agents targeting fungal, bacterial, and viral infections in patients with hematologic malignancies, focusing on those receiving hematopoietic cell transplantation or cellular therapies. We discuss immune checkpoint inhibitors, granulocyte transfusions, bone marrow colony-stimulating factors, bacteriophages, fecal microbiota transplantation, and virus specific T-cell therapy. Although there is promising early experience with many of these treatments, further studies will be required to define their optimal role in the therapeutic armamentarium against infections in immunocompromised hosts.

How I approach diarrhea in hematological transplant patients: A practical tool

Diarrhea in hematopoietic stem-cell transplantation (HSCT) remains a multifactorial challenge that demands a nuanced diagnostic approach. The causes of infectious diarrhea in HSCT recipients are diverse and influenced by patient-specific risk factors, the post-transplant timeline, and local epidemiology. During the past decade, our understanding of diarrhea in HSCT has witnessed a transformative shift through the incorporation of gastrointestinal (GI) multiplex polymerase chain reaction (PCR) panels. However, the judicious application of these panels is imperative to avoid overtesting and prevent adverse outcomes. The challenge lies in distinguishing between the diverse causes of diarrhea, ascertaining the clinical significance of detected pathogens, and navigating the diagnostic uncertainty presented by several non-infectious conditions such as mucositis, intestinal dysbiosis, and acute graft-versus-host disease (aGvHD), all of which mimic infection. This review examines the landscape of infectious diarrhea in the HSCT population, encompassing both established (e.g., Cytomegalovirus, Clostridioides difficile, and norovirus) and emerging pathogens (e.g., sapoviruses, astroviruses). We propose a multifaceted diagnostic algorithm that combines clinical assessment, risk stratification, and tailored utilization of molecular platforms. While multiplex GI panels present invaluable opportunities for rapid and comprehensive pathogen detection, their judicious use is pivotal in preserving diagnostic stewardship. Customization of diagnostic algorithms tailored to local epidemiology ensures optimal patient care and resource utilization.

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.

An analysis of the outcomes of Clostridioides difficile occurring in intestinal transplant recipients requiring hospitalization

BACKGROUND

Organ transplantation is a known risk factor for Clostridioides difficile infection (CDI). There is limited published data on the impact of CDI in the intestinal transplant population.

METHODS

We utilized the National Readmission Database (2010-2017) to study the outcomes of CDI in patients having a history of intestinal transplantation. Association of CDI with readmission and hospital resource utilization was computed in multivariable models adjusted for demographics and comorbidities.

RESULTS

During 2010-2017, 8442 hospitalizations with the history of intestinal transplantation had indexed hospital admissions. Of these, 320 (3.8%) had CDI. CDI hospitalization in intestine transplant patients was associated with higher median cost $54 430 (IQR: 27 231, 109 980) as compared to patients who did not have CDI $48 888 (IQR: 22 578, 112 777), (β: 71 814 95% confidence intervals [CI]: 676-142 953, p = .048). The median length of stay was also longer for patients with CDI 7 (IQR: 4, 13) days as compared to 5 (IQR: 3, 11) days in non-CDI (β: 5.51 95% CI: 0.73-10.29, p = .02). The mortality rate, intestinal transplant complications, presence of malnutrition, acute kidney injury, ICU admissions, and sepsis were similar in both groups. CDI was the top cause of 30-day readmission in the intestinal transplant recipients with CDI during the index admission; the number of 30-day readmissions also increased from 2010 to 2017.

CONCLUSION

CDI hospitalization in post-intestine transplant patients occurs commonly and is associated with a longer length of stay and higher costs during hospitalization. The CDI was the most common cause of readmission after the index admission of CDI in these patients.

Chinese expert consensus on intestinal microecology and management of digestive tract complications related to tumor treatment (version 2022)

The human gut microbiota represents a complex ecosystem that is composed of bacteria, fungi, viruses, and archaea. It affects many physiological functions including metabolism, inflammation, and the immune response. The gut microbiota also plays a role in preventing infection. Chemotherapy disrupts an organism's microbiome, increasing the risk of microbial invasive infection; therefore, restoring the gut microbiota composition is one potential strategy to reduce this risk. The gut microbiome can develop colonization resistance, in which pathogenic bacteria and other competing microorganisms are destroyed through attacks on bacterial cell walls by bacteriocins, antimicrobial peptides, and other proteins produced by symbiotic bacteria. There is also a direct way. For example, Escherichia coli colonized in the human body competes with pathogenic Escherichia coli 0157 for proline, which shows that symbiotic bacteria compete with pathogens for resources and niches, thus improving the host's ability to resist pathogenic bacteria. Increased attention has been given to the impact of microecological changes in the digestive tract on tumor treatment. After 2019, the global pandemic of novel coronavirus disease 2019 (COVID-19), the development of novel tumor-targeting drugs, immune checkpoint inhibitors, and the increased prevalence of antimicrobial resistance have posed serious challenges and threats to public health. Currently, it is becoming increasingly important to manage the adverse effects and complications after chemotherapy. Gastrointestinal reactions are a common clinical presentation in patients with solid and hematologic tumors after chemotherapy, which increases the treatment risks of patients and affects treatment efficacy and prognosis. Gastrointestinal symptoms after chemotherapy range from nausea, vomiting, and anorexia to severe oral and intestinal mucositis, abdominal pain, diarrhea, and constipation, which are often closely associated with the dose and toxicity of chemotherapeutic drugs. It is particularly important to profile the gastrointestinal microecological flora and monitor the impact of antibiotics in older patients, low immune function, neutropenia, and bone marrow suppression, especially in complex clinical situations involving special pathogenic microbial infections (such as clostridioides difficile, multidrug-resistant Escherichia coli, carbapenem-resistant bacteria, and norovirus).

Infectious complications after second allogeneic hematopoietic cell transplant in adult patients with hematological malignancies

We conducted a retrospective review of the infectious complications and outcomes over a 2-year follow-up period of adult patients who received a second allogeneic hematopoietic cell transplant (2nd allo-HCT) during a five-year period at two cancer centers in Michigan. Sixty patients, of whom 44 (73%) had acute leukemia or myelodysplastic syndrome, were studied. The majority (n = 37,62%) received a 2nd allo-HCT because of relapsed leukemia. Infection episodes after the 2nd allo-HCT totaled 112. Bacteria were identified in 76 episodes, the majority of which occurred pre-engraftment. The most common infecting organisms were Enterococcus species and Clostridioides difficile. Viral infections, predominantly cytomegalovirus, accounted for 59 infection episodes and occurred mostly in pre-engraftment and early post-engraftment periods. There were 16 proven/probable fungal infections, of which 9 were invasive aspergillosis or candidiasis. Mortality was 45% (n = 27) at one year and 65% (n = 39) at 2 years after transplant, and 16 deaths (41%) were due to infection. Of those 16 infection deaths, 8 were bacterial, 4 fungal, 2 both bacterial and fungal, and 2 viral. Failure to engraft neutrophils or platelets was significantly associated with decreased survival, p < 0.0001 and p < 0.001, respectively. Infections are common after a 2nd allo-HCT and are associated with a high mortality rate.

Clostridioides difficile Infection in Patients after Organ Transplantation—A Narrative Overview

Clostridioides difficile infection (CDI) is one of the most common causes of antibiotic-associated diarrhea. The pathogenesis of this infection participates in the unstable colonization of the intestines with the physiological microbiota. Solid-organ-transplant (SOT) patients and patients after hematopoietic stem cell transplantation are more prone to CDI compared to the general population. The main CDI risk factors in these patients are immunosuppressive therapy and frequent antibiotic use leading to dysbiosis. The current review article provides information about the risk factors, incidence and course of CDI in patients after liver, kidney, heart and lung transplantation and hematopoietic stem cell transplantation.

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 for clostridioides difficile prophylaxis in allogenic hematopoietic cell transplant

BACKGROUND

Neutropenia and antibiotic use put patients at risk for Clostridioides difficile infection (CDI) following allogenic hematopoietic cell transplant (alloHCT). CDI following alloHCT has been associated with acute graft versus host disease (aGVHD), a significant cause of morbidity and mortality in this population. We sought to evaluate if prophylactic oral vancomycin reduces the incidence of CDI in alloHCT recipients.

METHODS

We conducted a single center retrospective chart review to compare the effectiveness of oral vancomycin prophylaxis versus no prophylaxis in alloHCT recipients at the University of Kansas Health System. Vancomycin for CDI prophylaxis was implemented in March of 2018 at the University of Kansas Health System. Review of 100 consecutive alloHCT patients before and after this implementation was used to compare outcomes. Patients received oral vancomycin 125 mg twice daily starting on the day of inpatient admission for alloHCT and continued until discharge. The primary outcome is the incidence of CDI in patients with oral vancomycin prophylaxis compared to those who did not receive prophylaxis during hospital admission for alloHCT. The secondary endpoints include the incidence of acute grade 2-4 GVHD, and event free survival for each arm.

RESULTS

11% of patients developed CDI in the control group vs. 2% of patients in the intervention group (p = 0.018). Oral vancomycin was not associated with a higher risk of acute GVHD grade 2-4 (36% vs. 38%; P = 0.77) at day 100 post-transplant. No difference was seen in Event Free Survival.

CONCLUSIONS

Oral vancomycin was associated with reduced CDI incidence in patients that underwent an alloHCT without negatively affecting post-transplant outcomes. The contribution of confounders cannot be excluded. This article is protected by copyright. All rights reserved.

Clostridioides difficile infection in solid organ and hematopoietic stem cell transplant recipients: A prospective multinational study

BACKGROUND

Clostridioides difficile infection (CDI) is a significant cause of morbidity and mortality in recipients of solid organ transplant (SOT) or hematopoietic stem cell transplant (HSCT). In retrospective single center analyses, severe disease and relapse are common. We undertook an international, prospective cohort study to estimate the response to physician determined antibiotic treatment for CDI in patients with SOT and HSCT.

METHODS

Adults with a first episode of CDI within the first 2 years of SOT or HSCT were enrolled. Demographics, comorbidities, and medication history were collected, and over 90 days of follow-up clinical cure, recurrences, and complications were assessed. Logistic regression was used to study associations of baseline predictors of clinical cure and recurrence. Odds ratios (ORs) and 95% confidence intervals (CIs) are cited.

RESULTS

A total of 132 patients, 81 SOT and 51 HSCT (32 allogeneic), were enrolled with a median age of 56 years; 82 (62%) were males and 128 (97%) were hospitalized at enrollment. One hundred and six (80.3%) were diagnosed by DNA assay. CDI occurred at a median of 20 days post-transplant (interquartile range, IQR: 6-133). One hundred and eight patients (81.8%) were on proton pump inhibitors; 126 patients (95.5%) received antibiotics within the 6 weeks before CDI. The most common initial CDI treatments prescribed, on or shortly before enrollment, were oral vancomycin alone (50%) and metronidazole alone (36%). Eighty-three percent (95% CI: 76, 89) of patients had clinical cure; 18% (95% CI: 12, 27) of patients had recurrent CDI; global clinical cure occurred in 65.2%. Of the 11 patients who died, two (1.5% of total) were related to CDI. In multivariable logistic regression analyses, the type of initial treatment was associated with clinical cure (p = .009) and recurrence (p = .014). A history of cytomegalovirus (CMV) after transplant was associated with increased risk of recurrence (44% with versus 13% without CMV history; OR: 5.7, 95% CI: 1.5, 21.3; p = .01).

CONCLUSIONS

Among adults who develop CDI after SOT or HSCT, despite their immunosuppressed state, the percentage with clinical cure was high and the percentage with recurrence was low. Clinical cure and recurrence varied by type of initial treatment, and CMV viremia/disease was associated with an increased risk of recurrence.

The outcomes of Clostridioides difficile infection in inpatient liver transplant population

BACKGROUND

Chronic immunosuppression is a known cause of Clostridioides difficile, which presents with colon infection. It is associated with increased mortality and morbidity. Our aim is to determine the inpatient outcomes of liver transplant patients with Clostridioides difficile infection (CDI) and trends in the last few years.

METHODS

We utilized the national re-admission data (2010-2017) to study the outcomes of CDI in liver transplant patients. Association of C. difficile with re-admission was computed in a multivariable model adjusted for age, sex, gastrointestinal bleeding, hypertension, diabetes, hyperlipidemia, congestive heart failure, cerebrovascular disease, obesity, cancer, insurance, chronic kidney disease, chronic obstructive pulmonary disease, dementia, peripheral vascular disease, smoking, hospital location, and teaching status.

RESULTS

During 2010-2017, there were 310 222 liver transplant patients hospitalized. Out of these, 9826 had CDI. CDI infection in liver transplant patients was associated with higher 30-day re-admission (14.3% vs. 11.21%, hazard ratio [HR]: 1.14, 95% confidence interval [CI]: 1.01-1.28, p = .02) and in-hospital mortality (odds ratio [OR]: 1.36, 95% CI: 1.14-1.61, p < .001). The most common causes of re-admission in the CDI group were recurrent CDI (41.1%), liver transplant complications (16.5%), and sepsis (11.6%). The median cost for liver transplant patients with C. difficile was significantly higher, $53 064 (IQR $24 970-$134 830) compared to patients that did not have C. difficile, $35 703 ($18 793-$73 871) (p < .001). The median length of stay was also longer for patients with CDI, 6 days (4-14) vs. 4 days (2-7) (p < .001).

CONCLUSION

CDI in post-liver transplant patients was associated with higher mortality, re-admission, health care cost, and longer length of stay. The most common cause of re-admission was recurrent CDI, which raises the question of the efficacy of standard first-line therapy.

Early Clostridioides difficile infection characterizations, risks, and outcomes in allogeneic hematopoietic stem cell and solid organ transplant recipients

BACKGROUND

Clostridioides difficile infection (CDI) frequently complicates allogeneic hematopoietic stem cell (allo-HCT) and solid organ transplantation (SOT).

METHODS

We retrospectively analyzed risk factors and outcomes of CDI occurring within 30 days of transplant.

RESULTS

Between March 2010 and June 2015, 466 allo-HCT and 1454 SOT were performed. The CDI cumulative incidence (95% CI) was 10% (8-13) and 4% (3-5), following allo-HCT and SOT, respectively (p < .01), occurring at a median (range) 7.5 days (1-30) and 11 (1-30), respectively (p = .18). In multivariate analysis, fluoroquinolones use within 14 days pre-transplantation was a risk factor for CDI following allo-HCT (HR 4.06 [95% CI 1.31-12.63], p = .02), and thoracic organ(s) transplantation was a risk factor for CDI following SOT (HR 3.03 [95% CI 1.31-6.98]) for lung and 3.90 (1.58-9.63) for heart and heart/kidney transplant, p = .02. Compared with no-CDI patients, the length of stay (LOS) was prolonged in both allo-HCT (35 days [19-141] vs. 29 [13-164], p < .01) and SOT with CDI (16.5 [4-101] vs. 7 [0-159], p < .01), though not directly attributed to CDI. In allo-HCT, severe acute graft-versus-host disease (aGVHD) occurred more frequently in patients with CDI (33.3% vs. 15.8% without CDI, p = .01) and most aGVHD (87.5%) followed CDI. Non-relapse mortality or overall survival, not attributed to CDI, were also similar in both allo-HCT and SOT.

CONCLUSIONS

Early post-transplant CDI is frequent, associated with fluoroquinolones use in allo-HCT and the transplanted organ in SOT, and is associated with longer LOS in both the groups without difference in survival but with increased aGVHD in allo-HCT.

Acute abdomen in the immunocompromised patient: WSES, SIS-E, WSIS, AAST, and GAIS guidelines

Immunocompromised patients are a heterogeneous and diffuse category frequently presenting to the emergency department with acute surgical diseases. Diagnosis and treatment in immunocompromised patients are often complex and must be multidisciplinary. Misdiagnosis of an acute surgical disease may be followed by increased morbidity and mortality. Delayed diagnosis and treatment of surgical disease occur; these patients may seek medical assistance late because their symptoms are often ambiguous. Also, they develop unique surgical problems that do not affect the general population. Management of this population must be multidisciplinary.This paper presents the World Society of Emergency Surgery (WSES), Surgical Infection Society Europe (SIS-E), World Surgical Infection Society (WSIS), American Association for the Surgery of Trauma (AAST), and Global Alliance for Infection in Surgery (GAIS) joined guidelines about the management of acute abdomen in immunocompromised patients.

The clinical role of the gut microbiome and fecal microbiota transplantation in allogeneic stem cell transplantation

Outcomes of allogeneic hematopoietic stem cell transplantation (allo- HSCT) have improved in the recent decade; however, infections and graft-versus-host disease remain two leading complications significantly contributing to early transplant-related mortality. In past years, the human intestinal microbial composition (microbiota) has been found to be associated with various disease states, including cancer, response to cancer immunotherapy and to modulate the gut innate and adaptive immune response. In the setting of allo-HSCT, the intestinal microbiota diversity and composition appear to have an impact on infection risk, mortality and overall survival. Microbial metabolites have been shown to contribute to the health and integrity of intestinal epithelial cells during inflammation, thus mitigating graft-versus-host disease in animal models. While the cause-andeffect relationship between the intestinal microbiota and transplant-associated complications has not yet been fully elucidated, the above findings have already resulted in the implementation of various interventions aiming to restore the intestinal microbiota diversity and composition. Among others, these interventions include the administration of fecal microbiota transplantation. The present review, based on published data, is intended to define the role of the latter approach in the setting of allo-HSCT.

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.

Risk Factors and Outcome of C. difficile Infection after Hematopoietic Stem Cell Transplantation

Patients who undergo hematopoietic stem cell transplants (HSCT) are at major risk of C. difficile (CD) infection (CDI), the most common cause of nosocomial diarrhea. We conducted a retrospective study, which enrolled 481 patients who underwent autologous (220) or allogeneic HSCT (261) in a 5-year period, with the aim of identifying the incidence, risk factors and outcome of CDI between the start of conditioning and 100 days after HSCT. The overall cumulative incidence of CDI based upon clinical evidence was 5.4% (95% CI, 3.7% to 7.8%), without any significant difference between the two types of procedures. The median time between HSCT and CDI diagnosis was 12 days. Out of 26 patients, 19 (73%) with clinical and symptomatic evidence of CDI were positive also for enzymatic or molecular detection of toxigenic CD; in particular, in 5 out of 26 patients (19%) CD binary toxin was also detected. CDI diagnoses significantly increased in the period 2018-2019, since the introduction in the microbiology lab unit of the two-step diagnostic test based on GDH immunoenzymatic detection and toxin B/binary toxin/027 ribotype detection by real-time PCR. Via multivariate analysis, abdominal surgery within 10 years before HSCT (p = 0.002), antibiotic therapy within two months before HSCT (p = 0.000), HCV infection (p = 0.023) and occurrence of bacterial or fungal infections up to 100 days after HSCT (p = 0.003) were significantly associated with a higher risk of CDI development. The 26 patients were treated with first-line vancomycin (24) or fidaxomicine (2) and only 2 patients needed a second-line treatment, due to the persistence of stool positivity. No significant relationship was identified between CDI and the development of acute graft versus host disease (GVHD) after allogeneic HSCT. At a median follow-up of 25 months (range 1-65), the cumulative incidence of transplant related mortality (TRM) was 16.6% (95% CI 11.7% to 22.4%) and the 3-year overall survival (OS) was 67.0% (95% CI 61.9% to 71.6%). The development of CDI had no significant impact on TRM and OS, which were significantly impaired in the multivariate analysis by gastrointestinal and urogenital comorbidities, severe GVHD, previous infections or hospitalization within two months before HSCT, active disease at transplant and occurrence of infections after HSCT. We conclude that 20% of all episodes of diarrhea occurring up to 100 days after HSCT were related to toxigenic CD infection. Patients with a history of previous abdominal surgery or HCV infection, or those who had received broad spectrum parenteral antibacterial therapy were at major risk for CDI development. CDIs were successfully treated with vancomycin or fidaxomicin after auto-HSCT as well as after allo-HSCT.

Clostridium difficile in Immunocompromised Hosts: A Review of Epidemiology, Risk Factors, Treatment, and Prevention

Clostridium difficile is a significant pathogen in healthcare today, impacting both hospitalized and community-based patients. Immunocompromised patients experience a high incidence of C. difficile infection, ranging from 6% to 33% in the hematology-oncology population and up to 23% among lung transplant recipients, and have a rate of 7.1-8.3 cases per 1000 patient-years in patients with human immunodeficiency virus (HIV). Recurrence of C. difficile infections among immunocompromised patients is also high, with rates up to 40% in both the hematology-oncology population and solid organ transplant recipients. This higher incidence of C. difficile infection and recurrence is believed to be secondary to frequent antimicrobial use, suppressed immune function, increased exposure to healthcare settings, and higher prevalence of C. difficile colonization. This review summarizes published data describing the epidemiology, risk factors for acquisition and infection, treatment, and prevention of C. difficile in hematology-oncology, solid organ transplant, and HIV-infected patients.

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.

Management and prophylaxis of bacterial and mycobacterial infections among lung transplant recipients

Bacterial and mycobacterial infections are associated with morbidity and mortality in lung transplant recipients. Infectious complications are categorized by timing post-transplant: <1, 1–6, and >6 months. The first month post-transplant is associated with the highest risk of infection. During this period, infections are most commonly healthcare-associated, and include infections related to surgical complications. The lungs and bloodstream are common sites of infections. Common healthcare-associated organisms include methicillin-resistant Staphylococcus aureus (MRSA), Gram-negative bacilli such as Pseudomonas aeruginosa, and Clostridioides difficile. More than 1-month post-transplant, opportunistic infections can occur. Tuberculosis occurs in 0.8–10% of lung transplant recipients which reflects variation in background prevalence. The majority of post-transplant tuberculosis stems from reactivation of untreated or undiagnosed latent tuberculosis. Most post-transplant tuberculosis occurs in the lungs and develops within a year of transplant. Non-tuberculous mycobacteria commonly colonize the lungs of lung transplant candidates and are often hard to eradicate even with prolonged courses of antimycobacterial agents. Drug interactions between antimycobacterial agents and calcineurin and mTOR inhibitors also complicates treatment post-transplant. Given that infection adversely impacts outcomes after lung transplant, and that anti-infective therapy is often less effective after transplant, infection prevention is key to long-term success. A comprehensive approach that includes pre-transplant evaluation, perioperative prophylaxis, long-term antimicrobial prophylaxis, immunization, and safer living at home and in the community, should be employed to minimize the risk of infection.

Clostridioides difficile infection in immunocompromised hospitalized patients is associated with a high recurrence rate

OBJECTIVE

Clostridioides difficile infection (CDI) may pose a serious threat to immunocompromised patients (IMC). Herein, we evaluated the clinical outcomes of IMC patients with CDI.

METHODS

All consecutive hospitalized patients between January 1, 2013 and December 31, 2018 with laboratory confirmed CDI were included in the study. Subjects were divided into two groups: IMC patients and controls. Primary outcome was the recurrence rate of CDI (rCDI) at 30 and 90 days after the first CDI episode. Secondary outcomes included 30 and 90 day all-cause mortality, length of hospital stay (LOS) and readmission rates. A multivariate analysis adjusted other risk factors for recurrence. An analysis of IMC patient subgroups (based on type of IMC conditions) was also performed. Results are reported as odds ratios (OR) with a 95% confidence interval (95% CI).

RESULTS

A total of 573 patients were included, amongst them 149 IMC patients (36 solid organ transplants, 38 undergoing chemotherapy, 62 haematological conditions, 13 receiving high dose prednisone) and 424 controls. IMC patients were younger, independent and exhibited less significant comorbidities. On multivariable analysis, the rate of rCDI was significantly higher in IMC patients (OR 2.7, 95% CI 1.6-5). rCDI was also associated with vancomycin therapy, haemodialysis and previous hospitalizations. Mortality, LOS, CDI complications and rehospitalization rates were similar in both.

CONCLUSIONS

IMC patients with CDI have an increased risk of 90 days rCDI. Vancomycin treatment for CDI endangers recurrence in IMC patients. Further research should explore other therapies for IMC patients with CDI with alternative agents such as Fidaxomicin and Bezlotoxumab.

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.

The gut microbiota in transplant patients

Solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients are at increased risk for developing infections due to underlying immunosuppression. Antibiotic use, and in HSCT recipients, the use of preparative regimens prior to transplantation can deplete gut commensal bacteria, resulting in intestinal dysbiosis. Emerging evidence in transplant patients, particularly HSCT, suggest that disturbances in gut microbiota populations are associated with a number of adverse outcomes. Here, we review the outcomes of HSCT and SOT recipients with gut microbiota imbalance or dysbiosis, explore the nascent field of gut microbiome therapeutic approaches including fecal microbiota transplantation and the use of precision probiotics in HSCT and SOT recipients.

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.