Incidence of diarrhea by Clostridium difficile in hematologic patients and hematopoietic stem cell transplantation patients: risk factors for severe forms and death

Testing and Diagnosis of Clostridioides difficile Infection in Special Scenarios: A Systematic Review

INTRODUCTION

Clostridioides difficile infection (CDI) is a clinical and laboratory diagnosis. Populations at higher risk of developing disease require a high clinical index of suspicion for laboratory testing to avoid incorrect assumptions of colonization. Common risk factors include recent antibiotic use, elderly (>65 years old), and immunocompromised patients. C. difficile assays should be ordered in an algorithm approach to diagnose an infection rather than colonization. Screening tests are widely available in hospital systems, but novel molecular testing may aid in diagnosis in patients with inconclusive or discordant antigen and toxin test results.  Methods: Data was extracted from PubMed, Scopus, and Cumulative Index of Nursing and Allied Health Literature (CINAHL) databases based on the keywords "clostridioides difficile", "toxin assay", and "toxic megacolon". The data extracted is based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. A total of 27 reports were included in this systematic review.

RESULTS

Testing patients with a significant gastrointestinal surgical history, hypogammaglobulinemia, inflammatory bowel disease, intensive care unit, and immunocompromised patients for CDI is highly recommended. Diarrhea in these subsets of patients requires correlation of clinical context and an understanding of assay results to avoid over- and under-treating.

CONCLUSION

CDI should be considered in all patients with traditional risk factors. Heightened clinical suspicion of CDI is required in patients with hypogammaglobulinemia, transplant recipients, patients with gastrointestinal surgical history, and inflammatory bowel disease. Testing should be limited to patients with clinical manifestations of CDI to ensure a high pretest probability for test interpretation. Healthcare workers should adhere to testing algorithms to optimize yield in the appropriate clinical context. Diagnostic assays should follow a sequential, stepwise approach to categorize the toxin expression status of the bacteria accurately.

Mycophenolate mofetil increases the risk of diarrhea in allogeneic hematopoietic stem cell transplantation recipients

OBJECTIVES

Mycophenolate mofetil (MMF) was reported to be a main cause of diarrhea following organ transplantation. However, research on MMF-induced diarrhea following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is currently insufficient. This retrospective study examined the incidence of MMF-induced diarrhea among allo-HSCT recipients.

METHODS

Recipients were divided according to the receipt of MMF and the appearance of diarrhea. The differences in clinical information, MMF usage and trough concentrations, and the occurrence of diarrhea from the first day of conditioning treatment to 100 days after transplantation were analyzed.

RESULTS

In total, 32.9% of the recipients reported diarrhea. The incidence rate of diarrhea was higher in the MMF group than in the non-MMF group (40.0% vs. 16.7%). MMF-induced diarrhea usually occurred within 9 days of MMF initiation and persisted for 7.27 ± 3.54 days. The average body weight, MMF daily dose, and MMF trough concentration were higher in patients with diarrhea.

CONCLUSION

MMF increased the risk of diarrhea in allo-HSCT recipients, and the risk was related to the MMF dose and trough concentration. The difference in onset time could be a basis for identifying the cause of diarrhea in allo-HSCT recipients.

Metronidazole for Treatment of Clostridioides difficile Infections in Brazil: A Single-Center Experience and Risk Factors for Mortality

We describe the epidemiology of C. difficile infections (CDIs) focused on treatment and analyze the risk factors for mortality. This is a retrospective cohort study of CDI cases with a positive A/B toxin in the stool in 2017–2018. We analyzed the demographic data, comorbidities, previous use of antimicrobials, severity, and treatment, and we performed multivariate analysis to predict the 30-days mortality. We analyzed 84 patients, 37 (44%) of which were male, where the mean age was 68.1 years and 83 (99%) had comorbidities. The percentage of positivity of the A/B toxin was 11.6%, and the overall incidence density was 1.78/10,000 patient days. Among the patients, 65.4% had previous use of antimicrobials, with third-generation cephalosporins being the class most prescribed, and 22.6% of cases were severe. Treatment was prescribed for 70 (83.3%) patients, and there was no statistically significant difference between the initial treatment with metronidazole and vancomycin even in severe cases. The 30-day mortality was 7/84 (8.3%), and the risk factors associated with mortality was a severity score ≥2 (OR: 6.0; CI: 1.15–31.1; p = 0.03). In this cohort of CDI-affected patients with comorbidities and cancer, metronidazole was shown to be a good option for treating CDIs, and the severity score was the only independent risk factor for death.

Clostridioides difficile in Latin America: A comprehensive review of literature (1984-2021)

This narrative review summarizes literature on C. difficile and C. difficile infections (CDI) that emerged from Latin America (LA) between 1984 and 2021. The revised information includes papers in English, Spanish, or Portuguese that were retrieved from the databases Pubmed, Scopus, Web of Science, Google Scholar, Scielo, and Lilacs. Information is presented chronologically and segregated in subregions, focusing on clinical presentation, risk factors, detection and typing methods, prevalence and incidence rates, circulating strains, and, when available, phenotypic traits, such as antimicrobial susceptibility patterns. Studies dealing with cases, clinical aspects of CDI, and performance evaluations of diagnostic methods predominated. However, they showed substantial differences in case definitions, measuring units, populations, and experimental designs. Although a handful of autochthonous strains were identified, predominantly in Brazil and Costa Rica, the presentation and epidemiology of CDI in LA were highly comparable to what has been reported in other regions of the world. Few laboratories isolate and type this bacterium and even less generate whole genome sequences or perform basic science on C. difficile. Less than ten countries lead academic productivity on C. difficile or CDI-related topics, and information from various countries in Central America and the Caribbean is still lacking. The review ends with a global interpretation of the data and recommendations to further develop and consolidate this discipline in LA.

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.

A worldwide systematic review and meta-analysis of bacteria related to antibiotic-associated diarrhea in hospitalized patients

INTRODUCTION

Antibiotic-associated diarrhea (AAD) is a major hospital problem and a common adverse effect of antibiotic treatment. The aim of this study was to investigate the prevalence of the most important bacteria that cause AAD in hospitalized patients.

MATERIALS AND METHODS

PubMed, Web of Science and Scopus databases were searched using multiple relevant keywords and screening carried out based on inclusion/exclusion criteria from March 2001 to October 2021. The random-effects model was used to conduct the meta-analysis.

RESULTS

Of the 7,377 identified articles, 56 met the inclusion criteria. Pooling all studies, the prevalence of Clostridioides (Clostridium) difficile, Clostridium perfringens, Klebsiella oxytoca, and Staphylococcus aureus as AAD-related bacteria among hospitalized patients were 19.6%, 14.9%, 27%, and 5.2%, respectively. The prevalence of all four bacteria was higher in Europe compared to other continents. The highest resistance of C. difficile was estimated to ciprofloxacin and the lowest resistances were reported to chloramphenicol, vancomycin, and metronidazole. There was no or little data on antibiotic resistance of other bacteria.

CONCLUSIONS

The results of this study emphasize the need for a surveillance program, as well as timely public and hospital health measures in order to control and treat AAD infections.

Use of carbapenems and glycopeptides increases risk for Clostridioides difficile infections in acute myeloid leukemia patients undergoing intensive induction chemotherapy

Patients with acute myeloid leukemia (AML) are often exposed to broad-spectrum antibiotics and thus at high risk of Clostridioides difficile infections (CDI). As bacterial infections are a common cause for treatment-related mortality in these patients, we conducted a retrospective study to analyze the incidence of CDI and to evaluate risk factors for CDI in a large uniformly treated AML cohort. A total of 415 AML patients undergoing intensive induction chemotherapy between 2007 and 2019 were included in this retrospective analysis. Patients presenting with diarrhea and positive stool testing for toxin-producing Clostridioides difficile were defined to have CDI. CDI was diagnosed in 37 (8.9%) of 415 AML patients with decreasing CDI rates between 2013 and 2019 versus 2007 to 2012. Days with fever, exposition to carbapenems, and glycopeptides were significantly associated with CDI in AML patients. Clinical endpoints such as length of hospital stay, admission to ICU, response rates, and survival were not adversely affected. We identified febrile episodes and exposition to carbapenems and glycopeptides as risk factors for CDI in AML patients undergoing induction chemotherapy, thereby highlighting the importance of interdisciplinary antibiotic stewardship programs guiding treatment strategies in AML patients with infectious complications to carefully balance risks and benefits of anti-infective agents.

Multicenter study of the epidemiology of Clostridioides difficile infection and recurrence in southern Brazil

Clostridioides (Clostridium) difficile is the main etiology underlying antibiotic-associated diarrhea (AAD). Still, few Brazilian data are available on this infection. The aims of this multicenter study were to identify the prevalence, clinical characteristics, and outcomes of C. difficile infection (CDI) in patients with antibiotic associated diarrhea at eight hospitals in Curitiba, southern Brazil, during the years 2017-2019. Stool samples were tested using enzyme immunoassay for glutamate dehydrogenase antigen (GDH) and A/B toxins. Positive GDH samples were further evaluated by real-time polymerase chain reaction (PCR) for the presence of genes encoding toxin B (tcdB), binary toxin (cdt), and marker of hypervirulent C. difficile strain (tcdC deletion). The prevalence of CDI in 351 patients with AAD included in the study was 17.7% (n = 62). Among the CDI cases, tcdB was positive in all 62 stool samples, while cdt was positive in 10 samples, and tcdC deletion was positive in only two. Carriage of carbapenem-resistant Gram-negative bacilli, previous hospitalization, and use of broad-spectrum cephalosporin and carbapenem were associated with CDI. Among patients with CDI, 64.5% presented with severe diarrhea, and 8% (5/62) progressed with colitis and required intensive care. The 30-day mortality was 24% (15/62), and the CDI-associated mortality was 4.8% (3/62). Overall, 83.8% (52/62) of the patients achieved primary cure, and 20.8% of the evaluated patients (10/48) presented CDI recurrence. The treatment administered was not significantly associated with the 60-day recurrence or mortality. In conclusion, we reported in this study data of prevalence and recurrence rates of CDI in patients with AAD and evaluated the number of severe cases and infection-related mortality, which were up to now unknown in Southern Brazilian hospitals.

Brazilian Nutritional Consensus in Hematopoietic Stem Cell Transplantation: Adults

The nutritional status of patients submitted to hematopoietic stem cell transplant is considered an independent risk factor, which may influence on quality of life and tolerance to the proposed treatment. The impairment of nutritional status during hematopoietic stem cell transplant occurs mainly due to the adverse effects resulting from conditioning to which the patient is subjected. Therefore, adequate nutritional evaluation and follow-up during hematopoietic stem cell transplant are essential. To emphasize the importance of nutritional status and body composition during treatment, as well as the main characteristics related to the nutritional assessment of the patient, the Brazilian Consensus on Nutrition in Hematopoietic Stem Cell Transplant: Adults was prepared, aiming to standardize and update Nutritional Therapy in this area. Dietitians, nutrition physicians and hematologists from 15 Brazilian centers thar are references in hematopoietic stem cell transplant took part.

A Single-Center Experience and Literature Review of Management Strategies for Clostridium difficile Infection in Hematopoietic Stem Cell Transplant Patients

Introduction

The aim of our study is to evaluate risk factors associated with the development of C. difficile infection (CDI) in hematopoietic stem cell transplant (HSCT) patients, determine its incidence and report outcomes of CDI in our patient population.

Methods

We performed a retrospective review of medical records of adult HSCT recipients diagnosed between 2013 and 2016 at our center. Logistic regression models were used to determine the relationship between risk factors and the odds of CDI.

Results

The overall incidence of CDI in HSCT patients was 9.4%. The incidence of CDI was higher in allogeneic HSCT (20%) versus autologous HSCT (4.8%). No statistically significant differences in age, gender, cancer type, transplant type were found between those who developed CDI and those who did not. However, patients with CDI had a longer length of stay (25 days) and used more antibiotics (30 days prior to and during admission for HSCT) than non-CDI patients (19 days). Only two of 17 patients (11.8%) with CDI experienced recurrence among 180 patients after HSCT. No patient suffered from toxic megacolon or ileus and no patient underwent colectomy. There was no mortality associated with CDI at our center.

Conclusion

CDI has an incidence rate of 9.4% in HSCT recipients. Established risk factors including age, gender, cancer type, and transplant type were not identified as risk factors in our population. However, longer LOS and use of greater than four lines of antibiotics were observed among those with CDI compared to those without CDI.

Current approach to early gastrointestinal and liver complications of hematopoietic stem cell transplantation

The gastrointestinal (GI) system is one of the most commonly affected sites during a hematopoietic stem cell transplantation (HSCT) due to toxicities of preparative regimens, the accompanying immunodeficiency, and organ damage caused by graft versus host disease. In this review, we focus on early GI and liver complications following autologous (auto-) and allogeneic (allo-) HSCT and clarify both the risk factors and therapeutic strategies. Early GI and liver complications associated with HSCT remain challenging issues. Despite the improvements in this field during the last decade, treatments for these complications still place a significant burden on both patients and the physicians treating these patients. GI and liver complications remain some of the causes of mortality associated with HSCT. For practicing hematologists, oncologists, and gastroenterologists in this field, the awareness and early diagnosis of the GI complications remain important factors to obtain optimal outcomes in this patient population.

Determining the risk factors associated with the development of Clostridium difficile infection in patients with hematological diseases

Background

Clostridium difficile infection (CDI) is a nosocomial condition prevalent in patients with hematological disorders. We aimed to identify the risk factors associated with the development of CDI and assess the mortality rate at 15 and 30 days among hematologic patients admitted to a tertiary care center.

Methods

We conducted a retrospective case-control study from January 2010 to December 2015. Forty-two patients with hematologic malignancy and CDI, and 84 with hematologic disease and without history of CDI were included in the case and control groups, respectively.

Results

Univariate analysis revealed that episodes of febrile eutropenia [odds ratio (OR), 5.5; 95% confidence interval (CI), 2.3-12.9; P<0.001], admission to intensive care unit (OR, 3.8; 95% CI, 1.4-10.2; P=0.009), gastrointestinal surgery (OR, 1.2; 95% CI, 1.1-1.4; P<0.001), use of therapeutic (OR, 6.4; 95% CI, 2.5-15.9; P<0.001) and prophylactic antibiotics (OR, 4.2; 95% CI, 1.6-10.7; P=0.003) in the last 3 months, and >1 hospitalization (OR, 5.6; 95% CI, 2.5-12.6; P<0.001) were significant risk factors. Multivariate analysis showed that use of therapeutic antibiotics in the last 3 months (OR, 6.3; 95% CI, 2.1-18.8; P=0.001) and >1 hospitalization (OR, 4.3; 95% CI, 1.7-11.0; P=0.002) were independent risk factors. Three (7.1%) and 6 (14.2%) case patients died at 15 and 30 days, respectively.

Conclusion

The risk factors for developing CDI were exposure to therapeutic antibiotics and previous hospitalization. Hematological patients who developed CDI had higher early mortality rates, suggesting that new approaches for prevention and treatment are needed.

Risk, Outcomes, and Predictors of Clostridium difficile Infection in Lymphoma: A Nationwide Study

OBJECTIVE

The risk of Clostridium difficile infection (CDI) has not been well studied in patients with lymphoma. We thus sought to determine the risk of CDI in hospitalizations with lymphoma along with its trend, outcomes, and predictors using a large database.

METHODS

Hospital discharge data from the Nationwide Inpatient Sample (NIS) from 2007 to 2011 were used for the study. Using the International Classification of Diseases, Ninth Revision, Clinical Modification codes, all adult patients aged 18 years or older having a primary diagnosis of lymphoma were queried for the presence of CDI as any of the secondary diagnoses. The risk of CDI in lymphoma and its yearly trend were assessed. We performed multivariate logistic regression to determine the independent risk factors of CDI in lymphoma. Furthermore, we studied mortality and other adverse outcomes of CDI in patients with lymphoma.

RESULTS

There were 236,312 discharges (weighted) with the primary diagnosis of lymphoma. CDI was present in 2.13% of patients with lymphoma versus 0.8% in the nonlymphoma group (P < 0.001). On multivariate analysis, the significant predictors of CDI in lymphoma were presence of infection (odds ratio [OR] 3.1, 95% confidence interval [CI] 2.7-3.6), stem cell transplant (OR 2.7, 95% CI 2.3-3.4), graft-versus-host disease (OR 1.9, 95% CI 1.4-2.8), race (Asian vs white, OR 1.6, 95% CI 1.1-2.4), chemotherapy (OR 1.6, 95% CI 1.4-1.8), gastrointestinal surgery (OR 1.4, 95% CI 1.2-1.7), and Charlson Comorbidity Index (CCI) (CCI of 2 vs 0-1: OR 1.2, 95% CI 1.1-1.4; CCI of 3 vs 0-1: OR 1.3, 95% CI 1.03-1.6). CDI in lymphoma was associated with worse hospital outcomes such as increased mortality (17% vs 8%), increased length of stay (23.6 vs 9.9 days), mean total hospital charges ($197,015 vs $79,392), rate of intubation (13% vs 4% vs 13%), and rate of total parenteral nutrition (11% vs 3%).

CONCLUSIONS

Hospitalization with lymphoma was associated with an increased risk of CDI. The significant predictors for CDI in lymphoma were infection, stem cell transplant, graft-versus-host disease, race, chemotherapy, gastrointestinal surgery, and Charlson Comorbidity Index. CDI in lymphoma was associated with increased mortality and other adverse outcomes warranting a need of more vigilance for CDI in patients with lymphoma.

Clostridium difficile-associated Diarrhea in Developing Countries: A Systematic Review and Meta-Analysis

INTRODUCTION

The prevalence of Clostridium difficile infection is rapidly increasing worldwide, but prevalence is difficult to estimate in developing countries where awareness, diagnostic resources, and surveillance protocols are limited. As diarrhea is the hallmark symptom, we conducted a systematic review and meta-analysis to determine the prevalence and incidence of C. difficile infection in patients in these regions who presented with diarrhea.

METHODS

We conducted a systematic literature search of MEDLINE/PubMed, Scopus, and Latin-American and Caribbean Health Sciences Literature databases to identify and analyze data from recent studies providing prevalence or incidence rates of C. difficile-associated diarrhea in developing countries within four regions: Africa-Middle East, developing Asia, Latin America, and China. Our objectives were to determine the current prevalence and incidence density rates of first episodes of C. difficile-associated diarrhea in developing countries.

RESULTS

Within the regions included in our analysis, prevalence of C. difficile infection in patients with diarrhea was 15% (95% CI 13-17%) (including community and hospitalized patients), with no significant difference across regions. The incidence of C. difficile infection in 17 studies including this information was 8.5 per 10,000 patient-days (95% CI 5.83-12.46). Prevalence was significantly higher in hospitalized patients versus community patients (p  = 0.0227).

CONCLUSION

Our prevalence estimate of 15% is concerning; however, low awareness and inconsistent diagnostic and surveillance protocols suggest this is markedly underestimated. Enhanced awareness and management of C. difficile infection in patients with diarrhea, along with improvements in infection control and surveillance practices, should be implemented to reduce prevalence of C. difficile-associated diarrhea in developing countries.

FUNDING

Pfizer Inc.

Evaluation of a multiplex panel for the diagnosis of acute infectious diarrhea in immunocompromised hematologic patients

Introduction

Diarrhea is a frequent complication in hematologic patients, being an infectious cause frequently suspected. Rapid and accurate detection of gastrointestinal pathogens is vital in immunocompromised hosts. The aim of this study was to compare routine diagnostic methods versus a multiplex polymerase chain reaction (PCR) assay for the diagnosis of infectious diarrhea in immunocompromised hematologic patients.

Material and methods

We conducted a prospective observational study from March 2015 to January 2016 to compare conventional methods for the diagnosis of infectious diarrhea with FIlmArray GI Panel (BioFire-bioMérieux, France). Samples from adult immunocompromised hematologic patients with acute diarrhea were collected. In cases with discordant results, a second multiplex assay was performed (Allplex, Seegene, Korea). The result was considered positive or negative when the same result was obtained by at least two of the methods.

Results

A total of 95 samples were obtained from 95 patients (median age of 52 years (46–64)). Sixty-one (64%) episodes were hospital-acquired and 34 (36%) were community-acquired diarrhea. Twenty-five (26%) patients had a positive microbiological result, being Clostridium difficile the most frequent pathogen, followed by Campylobacter spp and norovirus. The concordance between FilmArray methods was good (k = 0.79). The FilmArray GI panel showed a sensitivity of 95%, a specificity of 100% for positive results. The time required to obtain results was markedly reduced with the use of multiplex PCR methods.

Conclusions

Multiplex molecular panels provide a rapid and sensitive tool for the diagnosis of infectious diarrhea, thereby allowing more timely clinical decisions in immunocompromised hematologic patients.

Evaluation of Risk Factors for Clostridium difficile Infection in Hematopoietic Stem Cell Transplant Recipients

STUDY OBJECTIVES

The primary objective was to determine the impact of hematologic malignancies and/or conditioning regimens on the risk of developing Clostridium difficile infection (CDI) in patients undergoing hematopoietic stem cell transplantation (HSCT). Secondary objectives were to determine if traditional CDI risk factors applied to patients undergoing HSCT and to determine the presence of CDI markers of severity of illness among this patient population.

DESIGN

Single-center retrospective case-control study.

SETTING

Quaternary care academic medical center.

PATIENTS

A total of 105 patients who underwent HSCT between December 2009 and December 2014; of these patients, 35 developed an initial episode of CDI (HSCT/CDI group [cases]), and 70 did not (controls). Controls were matched in a 2:1 ratio to cases based on age (± 10 yrs) and date of HSCT (± 6 mo).

MEASUREMENTS AND MAIN RESULTS

Baseline characteristics of the two groups were well balanced regarding age, sex, race, ethnicity, and type of HSCT. No significant differences in conditioning regimen, hematologic malignancy, total body irradiation received for HSCT, use of antibiotics within 60 days of HSCT, or use of prophylactic antibiotics after HSCT were noted between the two groups. Patients in the control group were 10.57 (95% confidence interval 1.24-492.75) more likely to have received corticosteroids prior to HSCT than patients in the HSCT/CDI group (p=0.01). Use of proton pump inhibitors at the time of HSCT was greater among the control group than among patients in the HSCT/CDI group (97% vs 86%, p=0.048). No significant difference in mortality was noted between the groups at 3, 6, and 12 months after HSCT. Metronidazole was frequently prescribed for patients in the HSCT/CDI group (34 patients [97%]). Severe CDI was not common among patients within the HSCT/CDI group (13 patients [37%]); vancomycin was infrequently prescribed for these patients ([31%] 4/13 patients).

CONCLUSION

Hematologic malignancies and a conditioning regimen administered for HSCT were not significant risk factors for the development of CDI after HSCT. Use of corticosteroids prior to HSCT and use of proton pump inhibitors at the time of HSCT were associated with a significantly decreased risk of CDI.

Clostridium difficile Infection

Clostridium difficile is an anaerobic, Gram-positive, spore-forming, toxin-secreting bacillus that has long been recognized to be the most common etiologic pathogen of antibiotic-associated diarrhea. C. difficile infection (CDI) is now the most common cause of health care-associated infections in the United States and accounts for 12% of these infections (Magill SS et al., N Engl J Med370:1198-1208, 2014). Among emerging pathogens of public health importance in the United States, CDI has the highest population-based incidence, estimated at 147 per 100,000 (Lessa FC et al., N Engl J Med372:825-834, 2015). In a report on antimicrobial resistance, C. difficile has been categorized by the Centers for Disease Control and Prevention as one of three "urgent" threats (http://www.cdc.gov/drugresistance/threat-report-2013/). Although C. difficile was first described in the late 1970s, the past decade has seen the emergence of hypertoxigenic strains that have caused increased morbidity and mortality worldwide. Pathogenic strains, host susceptibility, and other regional factors vary and may influence the clinical manifestation and approach to intervention. In this article, we describe the global epidemiology of CDI featuring the different strains in circulation outside of North America and Europe where strain NAP1/027/BI/III had originally gained prominence. The elderly population in health care settings has been disproportionately affected, but emergence of CDI in children and healthy young adults in community settings has, likewise, been reported. New approaches in management, including fecal microbiota transplantation, are discussed.

Clinical approach to diarrheal disorders in allogeneic hematopoietic stem cell transplant recipients

Diarrhea is a common complication of allogeneic hematopoietic stem cell transplant (HSCT), with an average incidence of approximately 40%-50%. A wide variety of etiologies can contribute to diarrhea in HSCT patients, including medication-induced mucosal inflammation, infections, graft-vs-host disease and cord colitis syndrome in umbilical cord blood transplant. Clinical manifestations can vary from isolated diarrheal episodes, to other organ involvement including pneumonia or myocarditis, and rarely multiorgan failure. The approach for diagnosis of diarrheal disorders in HSCT patients depends on the most likely cause. Given the risk of life-threatening conditions, the development of clinically significant diarrhea requires prompt evaluation, supportive care and specific therapy, as indicated. Serious metabolic and nutritional disturbances can happen in HSCT patients, and may even lead to mortality. In this review, we aim to provide a practical approach to diagnosis and management of diarrhea in the post-transplant period.

Clostridium difficile infection in Chilean patients submitted to hematopoietic stem cell transplantation

Introduction

Patients submitted to hematopoietic stem cell transplantation have an increased risk of Clostridium difficile infection and multiple risk factors have been identified. Published reports have indicated an incidence from 9% to 30% of transplant patients however to date there is no information about infection in these patients in Chile.

Methods

A retrospective analysis was performed of patients who developed C. difficile infection after hematopoietic stem cell transplantations from 2000 to 2013. Statistical analysis used the Statistical Package for the Social Sciences software.

Results

Two hundred and fifty patients were studied (mean age: 39 years; range: 17–69), with 147 (59%) receiving allogeneic transplants and 103 (41%) receiving autologous transplants. One hundred and ninety-two (77%) patients had diarrhea, with 25 (10%) cases of C. difficile infection being confirmed. Twenty infected patients had undergone allogeneic transplants, of which ten had acute lymphoblastic leukemia, three had acute myeloid leukemia and seven had other diseases (myelodysplastic syndrome, chronic myeloid leukemia, severe aplastic anemia). In the autologous transplant group, five patients had C. difficile infection; two had multiple myeloma, one had amyloidosis, one had acute myeloid leukemia and one had germinal carcinoma. The overall incidence of C. difficile infection was 4% within the first week, 6.4% in the first month and 10% in one year, with no difference in overall survival between infected and non-infected groups (72.0% vs. 67.6%, respectively; p-value = 0.56). Patients infected after allogeneic transplants had a slower time to neutrophil engraftment compared to non-infected patients (17.5 vs. 14.9 days, respectively; p-value = 0.008). In the autologous transplant group there was no significant difference in the neutrophil engraftment time between infected and non-infected patients (12.5 days vs. 11.8 days, respectively; p-value = 0.71). In the allogeneic transplant group, the median time to acute graft-versus-host disease was similar between the two groups (p-value = 0.08), as was the incidence of grades 1–4 acute graft-versus-host disease (40% vs. 48%; p-value >0.05).

Conclusion

The incidence of C. difficile infection after hematopoietic stem cell transplantation was low, with a significant number of cases occurring shortly after transplantation. Allogeneic transplants had a three-time higher risk of infection compared to autologous transplants, but this was not associated with increased mortality, decreased overall survival or higher risk of acute graft-versus-host disease.

Bacterial Infections in Hematopoietic Stem Cell Transplant Recipients

Bacterial infections are major complications after Hematopoietic Stem Cell Transplant (HSCT). They consist mainly of bloodstream infections (BSI), followed by pneumonia and gastrointestinal infections, including typhlitis and Clostridium difficile infection. Microbiological data come mostly from BSI. Coagulase negative staphylococci and Enterobacteriaceae are the most frequent pathogens causing approximately 25% of BSI each, followed by enterococci, P. aeruginosa and viridans streptococci. Bacterial pneumonia is frequent after HSCT, and Gram-negatives are predominant. Clostridium difficile infection affects approximately 15% of HSCT recipients, being more frequent in case of allogeneic than autologous HSCT. The epidemiology and the prevalence of resistant strains vary significantly between transplant centres. In some regions, multi-drug resistant (MDR) Gram-negative rods are increasingly frequent. In others, vancomycin-resistant enterococci are predominant. In the era of increasing resistance to antibiotics, the efficacy of fluoroquinolone prophylaxis and standard treatment of febrile neutropenia have been questioned. Therefore, a thorough evaluation of local epidemiology is mandatory to decide the need for prophylaxis and the choice of the best regimen for empirical treatment of febrile neutropenia. For the latter, individualised approach has been proposed, consisting of either escalation or de-escalation strategy. De-escalation strategy is recommended since resistant bacteria should be covered upfront, mainly in patients with severe clinical presentation and previous infection or colonisation with a resistant pathogen. Non-pharmacological interventions, such as screening for resistant bacteria, applying isolation and contact precautions should be put in place to limit the spread of MDR bacteria. Antimicrobial stewardship program should be implemented in transplant centres.

Outcomes and Risk Factors Associated with Clostridium difficile Diarrhea in Hospitalized Adult Patients

Background. The epidemiology of Clostridium difficile infection has changed over time. Therefore, it is essential to monitor the characteristics of patients at risk of infection and factors associated with poor prognosis. Objective. To evaluate factors associated with C. difficile infection and with poor prognosis in those with documented C. difficile colitis. Methods. A retrospective case-control study of 75 patients with documented C. difficile colitis and 75 controls with hospital-acquired diarrhea of other causes. Stepwise multiple logistic regression was used to identify factors associated with C. difficile infection among patients with hospital-acquired diarrhea. Results. Previous antibiotic treatment (odds ratio (OR), 13.3; 95% confidence interval (CI), 1.40–126.90), abdominal distension (OR, 3.85; 95% CI, 1.35–10.98), and fecal leukocytes (OR, 8.79; 95% CI, 1.41–54.61) are considered as predictors of C. difficile colitis; anorexia was negatively associated with C. difficile infection (OR, 0.15; 95% CI, 0.03–0.66). Enteral tube feeding was independently associated with a composite outcome that included in-hospital mortality, intensive care unit admission, and treatment failure (OR, 3.75; 95%CI, 1.24–11.29). Conclusions. Previous antibiotic use and presence of fecal leukocytes in patients with hospital-acquired diarrhea are associated with C. difficile colitis and enteral tube support with complications associated with C. difficile colitis.

Outcomes of Clostridium difficile infection in hospitalized leukemia patients: a nationwide analysis

BACKGROUND The incidence of Clostridium difficile infection (CDI) has increased among hospitalized patients and is a common complication of leukemia. We investigated the risks for and outcomes of CDI in hospitalized leukemia patients. METHODS Adults with a primary diagnosis of leukemia were extracted from the United States Nationwide Inpatient Sample database, 2005-2011. The primary outcomes of interest were CDI incidence, CDI-associated mortality, length of stay (LOS), and charges. In a secondary analysis, we sought to identify independent risk factors for CDI in leukemia patients. Logistic regression was used to derive odds ratios (ORs) adjusted for potential confounders. RESULTS A total of 1,243,107 leukemia hospitalizations were identified. Overall CDI incidence was 3.4% and increased from 3.0% to 3.5% during the 7-year study period. Leukemia patients had 2.6-fold higher risk for CDI than non-leukemia patients, adjusted for LOS. CDI was associated with a 20% increase in mortality of leukemia patients, as well as 2.6 times prolonged LOS and higher hospital charges. Multivariate analysis revealed that age >65 years (OR, 1.13), male gender (OR, 1.14), prolonged LOS, admission to teaching hospital (OR, 1.16), complications of sepsis (OR, 1.83), neutropenia (OR, 1.35), renal failure (OR, 1.18), and bone marrow or stem cell transplantation (OR, 1.27) were significantly associated with CDI occurrence. CONCLUSIONS Hospitalized leukemia patients have greater than twice the risk of CDI than non-leukemia patients. The incidence of CDI in this population increased 16.7% from 2005 to 2011. Development of CDI in leukemia patients was associated with increased mortality, longer LOS, and higher hospital charges.