Clostridium difficile-associated disease in human stem cell transplant recipients: coming epidemic or false alarm?

Sepsis in Immunocompromised Patients Without Human Immunodeficiency Virus

Sepsis remains among the most common complications from infectious diseases worldwide. The morbidity and mortality rates associated with sepsis range from 20% to 50%. The advances in care for patients with an immunocompromised status have been remarkable over the last 2 decades, but sepsis continues to be a major cause of death in this population Immunocompromised patients who are recipients of a solid organ or hematopoietic stem cell transplant are living longer with a better quality of life. However, some of these patients need lifelong treatment with immunosuppressive medications to maintain their transplant status. A consequence of the need for this permanent immunosuppression is the high risk of opportunistic, community, and hospital-acquired infections, all of which can lead to sepsis. In addition, the detection of serious infections may be more challenging owing to patients' lower ability to mount the clinical symptoms that usually accompany sepsis. This article provides an update on the current knowledge of sepsis in immunocompromised patients without human immunodeficiency virus. It reviews the most pertinent causes of sepsis in this population, and addresses the specific diagnostic and therapeutic challenges in neutropenia and solid organ and hematopoietic stem cell transplantation.

Clostridium Difficile infections in patients with AML or MDS undergoing allogeneic hematopoietic stem cell transplantation identify high risk for adverse outcome

Clostridium difficile (CD) infection is the main cause of nosocomial enterocolitis in western countries and in patients undergoing allogeneic hematopoietic stem cell transplantation (alloHCT). Recipients of alloHCT are at high risk for CD infection but large studies in this population are rare and conflicting results have been reported. We analyzed 727 patients with AML or MDS undergoing alloHCT in our center from 2004 to 2015. Ninety-six patients (13%) had CD infection and 103 patients (14%) were identified as asymptomatic carriers by screening at admission and once a week during aplasia. Patients with CD infection had a shorter median overall survival of 8 months (95% CI, 6-36 months) compared with 25 months (95% CI, 17-35 months) for patients without CD infection, (HR 1.4, p = 0.04). CD positive patients were less likely to develop acute graft-versus-host disease (aGvHD; HR 0.6, p = 0.004) compared with CD-negative patients, but did not show differences in gastrointestinal aGvHD (HR 0.9, p = 0.5). Symptomatic patients developed gastrointestinal aGvHD (HR 2.5, p = 0.02) more often compared with asymptomatic CD positive patients. This analysis demonstrates a high prevalence for CD infection in patients undergoing alloHCT. A significant lower overall survival for patients with CD infection could be demonstrated.

The Effects of Fecal Donors with Different Feeding Patterns on Diarrhea in a Patient Undergoing Hematopoietic Stem Cell Transplantation

Almost 90% of patients undergoing hematopoietic stem cell transplantation (HSCT) experience diarrheal episodes, which represent a severe, often life-threatening complication for these patients. Although fecal microbiota transplantation (FMT) represents an alternative treatment option for infection-related diarrhea, the application of FMT in HSCT patients is greatly restricted for safety reasons. Furthermore, the therapeutic outcomes of FMT as a diarrhea treatment are somewhat related to the choice of the FMT donor. Here, we comprehensively profiled the dynamic changes in the intestinal microbiota after FMT from two donors with different feeding patterns and the same severely diarrheal recipient undergoing HSCT via a 45-day clinical observation. Importantly, no adverse events attributed to FMT were observed. The stool volume and frequency of the patient were reduced when we used feces from donor #1 (mixed feeding), but these changes were not observed after FMT from donor #2 (exclusive breastfeeding). Interestingly, no obvious differences in overall diversity (Shannon) or richness (Chao1) between the two donors were observed. Additionally, Bifidobacterium accounted for 29.9% and 18.1% of OTUs in the stools of donors #1 and #2, respectively. Lactobacillus accounted for 16.3% and 2.9% of the stools of donors #1 and #2, respectively. Furthermore, through longitudinal monitoring of the patient, we identified 6 OTUs that were particularly sensitive to the different FMT complements. Together, we present a case report suggesting that the overall diversity of the intestinal microbiota may not be the only important element in the selection of an effective FMT donor.

Infections in Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has become a widely used modality of therapy for a variety of malignant and nonmalignant diseases. Despite advances in pharmacotherapy and transplantation techniques, infection remains one of the most severe and frequently encountered complications of allo-HSCT.

This chapter will address the risk factors for development of infection following allo-HSCT, including those related to the host, the conditioning regimen, and the graft, as well as the timing of opportunistic infections after allo-HSCT. The most common bacterial, viral, fungal, and parasitic infections, as well as issues surrounding their diagnostics and treatment, will be discussed. Finally, this chapter will address vaccination and other preventative strategies to be utilized when caring for patients undergoing allo-HSCT.

Prognosis of Clostridium difficile infection in adult oncohaematological patients: experience from a large prospective observational study

The aim of the study is to evaluate demographics, epidemiology, clinical characteristics, treatment and outcomes of Clostridium difficile infection (CDI) in patients with and without concurrent cancer. This is a prospective cohort study of consecutive primary CDI episodes in adults (January 2006-December 2016). CDI was diagnosed on the presence of diarrhoea and positive stool testing for toxigenic C. difficile. Univariate analysis assessed differences between cancer and non-cancer patients. Risk factors of all-cause 30-day mortality were determinate using the logistic multivariable procedure. In total, 787 CDI episodes were recorded, 191 in cancer patients (median age 64, IQR 50-73). Of these, 120 (63%) had solid and 71 (37%) haematological malignancies (24 received a stem cell transplant). At the CDI diagnosis, 158 (82.7%) cancer patients had prior antibiotics and 150 (78.5%) were receiving proton pump inhibitors. Fifty-seven (80.3%) patients with haematological and 52 (43.3%) with solid malignancies were under chemotherapy at diagnosis; 25 (35.2%) with haematological and 11 (9.2%) with solid malignancies had an absolute neutrophil count < 1000/mm³. Overall, 30-day mortality was higher in cancer patients than in those without (19.2 vs. 8.6% respectively, p < 0.001); recurrence rates did not vary significantly (11.1 vs. 11%, p = 0.936). By type of neoplasm, 30-day mortality was higher in patients with haematological malignancies and solid tumours than in patients without cancer (respectively, 25.4 vs. 8.6%; p < 0.001 and 15 vs. 8.6%; p < 0.001). Our results suggest that the prognosis of CDI (30-day mortality) is poorer in patients with cancer than in those without although percentages of recurrent infection are similar in these two patient populations.

Incidence, course, and outcome of Clostridium difficile infection in children with hematological malignancies or undergoing hematopoietic stem cell transplantation

Clostridium difficile infection (CDI) is one of the most common causes of nosocomial infectious diarrhea in children during anticancer therapy or undergoing hematopoietic stem cell transplantation (HSCT) in Europe. Immunosuppression in these patients is a risk factor for CDI. Malignant diseases, age, acute graft-versus-host disease (aGVHD), HLA mismatch, or use of total body irradiation may play an important role in CDI course. The aim of this study was to evaluate the incidence, course, and outcome of CDI in children treated for malignancy or undergoing HSCT. Between 2012 and 2015, a total number of 1846 patients were treated for malignancy in Polish pediatric oncological centers (PHO group) and 342 underwent transplantation (HSCT group). In PHO group, episodes of CDI occurred in 210 patients (14%). The incidence of CDI was higher in patients with hematological malignancies in comparison to that with solid tumors. Patients with acute myeloblastic leukemia had shorter time to episode of CDI than those with acute lymphoblastic leukemia. Patients over 5 years and treated for acute leukemia had more severe clinical course of disease in PHO group. In HSCT group, CDI occurred in 29 (8%) patients. The incidence of CDI was higher in patients transplanted for acute leukemia. The recurrence rate was 14.7% in PHO and 20.7% in HSCT patients. CDI incidence was highest in patients with hematological malignancies. Most of patients experienced mild CDI. Age < 5 years and diagnosis other than acute leukemia were the positive prognostic factors influencing clinical CDI course.

The evaluation of critically ill transplant patients with infectious diarrhea

PURPOSE OF REVIEW

The review summarizes the epidemiology, risk factors, clinical presentation, diagnosis and management of the most important etiologic agents of infectious diarrhea in critically ill transplant recipients.

RECENT FINDINGS

Diarrhea, frequently caused by infectious pathogens, can cause significant morbidity and mortality in transplant recipients. Diarrhea can lead to severe dehydration, acute renal failure, medication toxicity, rejection, graft-versus-host disease and impairs patients' quality of life. Opportunistic infectious pathogens can pose significant diagnostic and therapeutic challenges in immunocompromised hosts.

SUMMARY

In transplant recipients, it is vital to differentiate infectious from noninfectious diarrhea to adequately manage their therapeutic approach. Supportive measures and reduction in immunosuppression are essential for the treatment management.

Infectious diarrhea in autologous stem cell transplantation: high prevalence of coccidia in a South American center

Background

Diarrhea is frequently seen in autologous stem cell transplantation. Although toxicity related to conditioning is the most common cause, infectious pathogens can play a distinctive role particularly in certain regions and environments.

Methods

The role of enteropathogens was investigated in 47 patients submitted to autologous stem cell transplantation at a Brazilian center between May 2011 and May 2013. All patients who presented with diarrhea consented to stool sample analysis to identify the etiological agents including coccidia, Strongyloides sp., Clostridium difficile and other pathogenic bacteria.

Results

Thirty-nine patients (83%) had diarrhea, among whom seven (17.5%) presented with coccidia, three (7.5%) with Candida sp., one (2.5%) with C. difficile, and one (2.5%) with Giardia lamblia. There was a tendency toward a higher incidence of diarrhea in older patients (p-value = 0.09) and those who received conditioning with lomustine, etoposide, cytarabine, and melphalan (p-value = 0.083). Furthermore, the number of days of neutropenia was higher in patients with diarrhea (p-value = 0.06).

Conclusions

The high frequency of diarrhea caused by coccidia shows the importance of investigating and correctly identifying etiological agents and highlights the possible varieties of intestinal infections in patients who undergo autologous stem cell transplantation.

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.

Risk factors and epidemiology of Clostridium difficile infection in hematopoietic stem cell transplant recipients during the peritransplant period

BACKGROUND

Hematopoietic stem cell transplant (HSCT) recipients represent a high-risk group for developing Clostridium difficile (CD) infection (CDI). We aimed to identify specific risk factors for CDI in an HSCT patient population during the peritransplant period.

METHODS

We performed a case-control study within a cohort of HSCT patients who received a transplant from November 2010 to March 2013. Cases had a clinical presentation compatible with CDI and a positive stool sample Xpert^® C. difficile test. Controls were CDI negative and matched on age, gender, and transplant type. Peritransplant period was defined as -30 days or time of stem cell mobilization maneuver to 30 days post transplant in autologous SCT or 90 days post transplant in allogeneic SCT.

RESULTS

Of 781 HSCTs performed during the study period, 650 (83.2%) had a stool sample submitted for CD testing. Eight-six (13.2%) cases with CDI were identified. Most of the cases were diagnosed within a week after transplantation (median of 5 days). In adjusted analysis, prior hospitalization (odds ratio [OR]: 2.01, 95% confidence interval [CI] 1.2-3.36), prior cephalosporin administration (OR 2.72, 95% CI: 1.54-4.83), and prior chemotherapy (OR: 3.26, 95% CI: 1.92-5.5) were significantly associated with CDI.

CONCLUSIONS

Hospitalization, and prior antibiotic and chemotherapy use are risk factors that are not easily modifiable, which emphasizes the need to start investigating preventive or prophylactic strategies in this high-risk population.

Sepsis and Challenging Infections in the Immunosuppressed Patient in the Intensive Care Unit

In 2017, most intensive care units (ICUs) worldwide are admitting a growing population of immunosuppressed patients. The most common causes of pre-ICU immunosuppression are solid organ transplantation, hematopoietic stem cell transplantation, and infection due to human immunodeficiency virus. In this article, the authors review the most frequent infections that cause critical care illness in each of these 3 immunosuppressed patient populations.

Clostridium difficile-Associated Colitis Post-Transplant Is Not Associated with Elevation of Tacrolimus Concentrations

BACKGROUND

Diarrhea is a common condition after solid organ transplant (SOT); Clostridium difficile-associated colitis (CDAC) is one of the most common infections after SOT. We documented previously that some types of enteritis are associated with an elevation of tacrolimus (TAC) trough concentrations by interfering with the drug's complex metabolism.

PATIENTS AND METHODS

Tacrolimus concentrations of 25 SOT recipients including 12 renal and 13 liver recipients before, during, and after CDAC were analyzed retrospectively.

RESULTS

Median age of the 25 patients was 54 y (range, 36-71), there were 15 males and 10 females. Clostridium difficile-associated colitis developed at a median of 55 d (range 2-4551) post-SOT. Median TAC concentrations prior to the outbreak of CDAC were 6.9 ng/mL (range, <1.5-17.2), 5.6 ng/mL (range, <1.5-13.2) during diarrhea, and 7.4 ng/mL (range, <1.5-24.3) after resolution of diarrhea (p > 0.05, NS). Treatment of CDAC consisted of metronidazole for 14 d in all cases. All patients recovered from CDAC but seven patients had CDAC relapse.

CONCLUSIONS

In contrast to other types of infectious diarrhea such as rotavirus enteritis and cryptosporidiosis, CDAC is not associated with an increase in TAC concentrations. This is because C. difficile causes primarily colitis as opposed to other organisms, which are associated with enteritis.

Hospital-Associated Infections

Hospital-associated infection (HAI) in immunocompromised patients can result in high rates of morbidity and mortality. Infections caused by multidrug-resistant organisms (MDROs) are especially worrisome because of the limited choice of remaining antibiotics available when a patient becomes colonized or infected with an MDRO. It is therefore important that immunocompromised patients be cared for in an environment that limits the risk for acquiring infections. However, with healthcare being increasingly delivered in settings other than the traditional inpatient hospital wards, a bigger effort will need to be set forth to prevent or rapidly diagnose HAI. The last few years have seen a significant increase in the number of singleplex and multiplex molecular assays for the detection of many of the organisms responsible for HAI, but more is needed as infections caused by organisms like Legionella pneumophila and Aspergillus species are still diagnosed with methods that have relatively low yield and are slow to provide actionable results. Finally, the use of novel techniques for outbreak investigations will provide new information on transmission of infectious agents in healthcare settings and allow stronger, evidence-based recommendations to be developed for prevention of HAIs in the immunocompromised host.

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.

Risk for Clostridium difficile Infection After Allogeneic Hematopoietic Cell Transplant Remains Elevated in the Postengraftment Period

BACKGROUND

Clostridium difficile infection (CDI) is a frequent cause of diarrhea among allogeneic hematopoietic cell transplant (HCT) recipients. It is unknown whether risk factors for CDI vary by time posttransplant.

METHODS

We performed a 3-year prospective cohort study of CDI in allogeneic HCT recipients. Participants were enrolled during their transplant hospitalizations. Clinical assessments were performed weekly during hospitalizations and for 12 weeks posttransplant, and monthly for 30 months thereafter. Data were collected through patient interviews and chart review, and included CDI diagnosis, demographics, transplant characteristics, medications, infections, and outcomes. CDI cases were included if they occurred within 1 year of HCT and were stratified by time from transplant. Multivariable logistic regression was used to determine risk factors for CDI.

RESULTS

One hundred eighty-seven allogeneic HCT recipients were enrolled, including 63 (34%) patients who developed CDI. 38 (60%) CDI cases occurred during the preengraftment period (days 0-30 post-HCT) and 25 (40%) postengraftment (day >30). Lack of any preexisting comorbid disease was significantly associated with lower risk of CDI preengraftment (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.1-0.9). Relapsed underlying disease (OR, 6.7; 95% CI, 1.3-33.1), receipt of any high-risk antimicrobials (OR, 11.8; 95% CI, 2.9-47.8), and graft-versus-host disease (OR, 7.8; 95% CI, 2.0-30.2) were significant independent risk factors for CDI postengraftment.

CONCLUSIONS

A large portion of CDI cases occurred during the postengraftment period in allogeneic HCT recipients, suggesting that surveillance for CDI should continue beyond the transplant hospitalization and preengraftment period. Patients with continued high underlying severity of illness were at increased risk of CDI postengraftment.

The epidemiology of Clostridium difficile infection in patients with cancer

INTRODUCTION

Clostridium difficile infection (CDI) is a significant cause of healthcare-associated diarrhoea, and the emergence of endemic strains resulting in poorer outcomes is recognised worldwide. Patients with cancer are a specific high-risk group for development of infection. Areas covered: In this review, modifiable and non-modifiable risk factors for CDI in adult patients with haematological malignancy or solid tumours are evaluated. In particular, the contribution of antimicrobial exposure, hospitalisation and gastric acid suppression to risk of CDI are discussed. Recent advances in CDI treatment are outlined, namely faecal microbiota transplantation and fidaxomicin therapy for severe/refractory infection in cancer populations. Outcomes of CDI, including mortality are presented, together with the need for valid severity rating tools customised for cancer populations. Expert commentary: Future areas for research include the prognostic value of C. difficile colonisation in cancer patients and the potential impact of dedicated antimicrobial stewardship programs in reducing the burden of CDI in cancer units.

Evaluating risk factors for Clostridium difficile infection in adult and pediatric hematopoietic cell transplant recipients

Background

Although hematopoietic cell transplant (HCT) recipients are routinely exposed to classic risk factors for Clostridium difficile infection (CDI), few studies have assessed CDI risk in these high-risk patients, and data are especially lacking for pediatric HCT recipients. We aimed to determine incidence and risk factors for CDI in adult and pediatric allogeneic HCT recipients.

Methods

CDI was defined as having diarrhea that tested positive for C. difficile via PCR, cytotoxin assay, or dual enzyme immunoassays. We included all patients who received an allogeneic HCT from 2008 to 2012 at the Fred Hutchinson Cancer Research Center; those <1 year old or with CDI within 8 weeks pre-HCT were excluded. Patients were categorized by transplanting hospital (“adult” or “pediatric”) and followed for 100 days post-HCT.

Results

Of 1182 HCT recipients, CDI was diagnosed in 17 % (33/192) of pediatric recipients for an incidence of 20 per 10,000 patient-days, and 11 % (107/990) of adult recipients for an incidence of 12 per 10,000. Pediatric recipients were diagnosed a median of 51 days (interquartile range [IQR]: 5, 72) after HCT and adults at 16 days (IQR = 5, 49). Compared with calendar year 2008, pediatric recipients transplanted in 2012 were at increased risk for CDI (hazard ratio [HR] = 3.99, p =.02). Myeloablative conditioning increased CDI risk in adult recipients (HR = 1.81, p =.005).

Conclusions

Pediatric and adult allogeneic recipients are at high risk of CDI post-HCT, particularly adult recipients of myeloablative conditioning. Differences in CDI incidence between children and adults may have resulted from exposure differences related to age; therefore, separately evaluating these groups should be considered in future CDI studies.

Clostridium difficile infection (CDI) in children due to hypervirulent strains PCR-ribotype 027: An emblematic report of two cases

In this report, the first two cases of pediatric Clostridium difficile infection (CDI) due to the hypervirulent PCR-ribotype 027 in Italy are described as emblematic of the role of both the infecting C. difficile strain and patient status in the occurrence and clinical manifestation of CDI in children.

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.

Risk factors, outcomes and epidemiology associated with Clostridium difficile infection in patients with haematological malignancies in a tertiary care hospital in China

The purpose of this study was to evaluate the risk factors, outcomes and epidemiology associated with Clostridium difficile infection (CDI) in patients with haematological malignancies in a tertiary care hospital in China. C. difficile screening was performed on patients admitted for chemotherapy or haematopoietic stem cell transplantation between 2009 and 2013. C. difficile isolates were analysed by multilocus sequence typing, and a retrospective chart review was performed on all patients with a positive toxin assay. CDI was diagnosed in 21 haematology-oncology ward patients and 14 marrow transplantation service patients for a cumulative incidence of 1.89/1000 and 3.69/1000 patient-days, respectively. Univariate analyses showed that patients who received etoposide had an increased risk of CDI (odds ratio 4.25, 95 % confidence interval 1.32-13.64). There was only one patient death, for which CDI was not the primary cause. Ten sequence types (STs) were identified, of which ST-3 and ST-54 were the most common; the hypervirulent ST-1 (ribotype 027) and ST-11 (ribotype 078) C. difficile strains were not detected in the patients in this study. The incidence of CDI did not differ between patients receiving chemotherapy and those receiving haematopoietic stem cell transplantation. The only risk factor for chemotherapy patients was treatment with etoposide.

Infectious Complications

Infections remain a cause of significant morbidity and mortality following hematopoietic stem cell transplantation (HSCT). The conditioning regimen (chemotherapy, radiation therapy), mucosal damage, type of transplant, immune suppressive therapy, and graft-versus-host disease (GVHD) all predispose the HSCT recipient to infection. Abnormal B- and T-lymphocyte function results in impaired humoral and cellular immunity, respectively. Neutrophil function is impaired by the use of corticosteroids and other medications. Hypogammaglobulinemia and functional asplenia are common. The occurrence of infections in an individual patient varies according to the phase of the transplant process and reflects the type(s) of immune defect(s), underlying disease, endogenous host flora, exposure history, and pre-treatment infections.

Autologous hematopoietic cell transplantation: an update for clinicians

High-dose chemotherapy followed by transplantation of autologous hematopoietic progenitor cells has a proven track record of safety and efficacy in hematological malignancies and select solid tumors. The near-universal use of peripheral blood stem cells as source for autografts, routine growth factor support, and antimicrobial prophylaxis post transplantation has improved the safety of this procedure. However, the advent of highly active novel therapies in the last few years warrants reappraisal of the role of autologous transplantation in the therapeutic armamentarium of malignant disorder. This review summarizes the current role of autologous transplantation for hematological malignancies, discusses modern standards for patient selection, and highlights long-term care issues of transplant survivors from an internist's perspective. Role of tumor purging in autologous transplantation, novel transplant conditioning regimens, and post-transplant therapies to prevent disease relapse are reviewed.

Gastrointestinal pathology in transplant patients

The assessment of gastrointestinal (GI) specimens from transplant patients is complicated by the wide range of potentially rare pathologies that may be found in this clinical setting. Acute GI graft-versus-host disease (GvHD) is characterized by epithelial cell apoptosis, although there is increasing recognition that acute and/or chronic inflammation may also be present. By contrast, thus far there are no histological features known to be specific to chronic GI GvHD. Mycophenolate mofetil colitis may mimic both GvHD and inflammatory bowel disease, whereas both cytomegalovirus (CMV) and adenovirus infections can cause gland apoptosis. Post-transplant lymphoproliferative disorder should be considered if a Crohn's-like histological picture is seen, and granulomas in biopsies from umbilical cord blood recipients should raise a suspicion of cord colitis syndrome. Finally, the GI tract may be involved directly or indirectly by the disease that originally required haematopoietic stem cell or liver transplantation.

Clostridium difficile infection: a review of the literature

Clostridium difficile is a Gram-positive, strictly anaerobic, spore-forming bacterium. It is the most common cause of antibiotic-associated diarrhea in hospitals and other healthcare facilities and is of significant concern because of the increasing morbidity and mortality rates as well as increased health care costs. Spectrum of presentation of Clostridium difficile infection ranges from mild, self-limiting diarrhea, to serious diarrhea, pseudomembranous colitis and life-threatening fulminant colitis, which may result in death. Prompt identification of patients with symptomatic Clostridium difficile infection is essential as the majority of patients respond quickly to antimicrobial therapy. Prevention is best accomplished by implementation of infection-control measures and by judicious use of antimicrobial agents.

Clostridium difficile infection after allogeneic hematopoietic stem cell transplant: strain diversity and outcomes associated with NAP1/027

Allogeneic hematopoietic stem cell transplantation (HSCT) recipients are at high risk for developing Clostridium difficile infection (CDI). We studied the incidence, risk factors, NAP1/027 prevalence, and clinical outcomes, including acute lower gastrointestinal graft-versus-host disease (GI GVHD), associated with early CDI in this population. A retrospective review was conducted of patients who underwent allogeneic HSCT at Memorial Sloan Kettering Cancer Center from January 1, 2005 to September 30, 2010. Early CDI was defined as infection occurring from day -10 to day +40 from stem cell infusion. Among 793 patients who received allogeneic HSCTs, early CDI occurred in 11.9%; 56% cases were between day -5 and day +5. Overall incidence was 25.2 cases/10,000 at-risk days. There was a high prevalence of NAP1/027 strains during peak incidence (61% in 2008). NAP1/027 was the most common strain in both adult and pediatric cases (24% and 23%, respectively). CDI was clinically mild, including those due to NAP1/027. Metronidazole was the primary treatment for 91 of 94 patients, 7 of 8 cases refractory to metronidazole had no response to vancomycin, and none was due to NAP1/027. Relapse of CDI was common (31%). The cumulative incidence of GI GVHD in patients with and without early CDI was 6.8% and 8%, respectively (P = .5). Most cases of CDI occurred during conditioning or immediately after transplant. Despite high prevalence of NAP1/027, we found only mild disease. Most patients were treated successfully with metronidazole, irrespective of NAP1/027 status. There was no significant association between early CDI and subsequent development of GI GVHD. This study demonstrates the high incidence of CDI early after allogeneic HSCT with wide diversity among infecting strains. Despite the high prevalence of NAP1/027, the disease is mild but relapses are common. No association was found between CDI and subsequent development of GI GVHD.

Infectious complications of stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is an accepted treatment for a variety of hematologic malignancies. The profound immunosuppression these patients experience adversely affects their risk of infection. This risk is much higher than in the general population and requires aggressive diagnostic and therapeutic interventions. The chapter will outline the major infections after HSCT.

Relative incidences and outcomes of Clostridium difficile infection following transplantation of unrelated cord blood, unrelated bone marrow, and related peripheral blood in adult patients: a single institute study

BACKGROUND

Clostridium difficile is a major cause of nosocomial diarrhea. The incidence and prognosis of C. difficile-associated diarrhea (CDAD) has not yet been assessed in adult patients after unrelated cord blood transplantation (uCBT).

METHODS

The medical records of 135 adult unrelated cord blood transplant recipients were reviewed retrospectively to investigate the clinical features of CDAD after uCBT. These data were compared to medical records of 39 unrelated bone marrow transplant recipients and 27 related peripheral blood stem cell transplant recipients as controls.

RESULTS

A total of 17 recipients developed CDAD, with onset occurring at a median of 22 days (range, 0-56 days) after transplantation. Among the unrelated cord blood transplant recipients, 11 (9%) developed CDAD. These results were comparable with those of CDAD after unrelated bone marrow transplantation (uBMT) (2/39, 6%) and related peripheral blood stem cell transplantation (rPBSCT) (4/27, 16%) (P=0.37). Fifteen of the infected recipients were successfully treated with oral metronidazole, vancomycin, or cessation of antibiotics. The remaining 2 recipients who developed CDAD after uCBT died of other causes. The development of CDAD did not negatively affect overall survival after uCBT.

CONCLUSIONS

These data indicate that the incidence and prognosis of CDAD after uCBT are comparable with those after uBMT and rPBSCT.

Clostridium difficile colonization and disease in patients undergoing hematopoietic stem cell transplantation

There was an increase in the Clostridium difficile infection (CDI) rate in our bone marrow transplantation unit. To evaluate the role of unit-based transmission, C. difficile screening was performed on adult patients admitted for hematopoietic stem cell transplantation (HSCT) over a 2-year period, and C. difficile isolates were typed. C. difficile testing was performed using a 2-step C. difficile glutamate dehydrogenase antigen plus toxin A/B enzyme immunoassay (EIA) and cytotoxin assay (or molecular toxin assay). Multilocus sequence typing (MLST) was performed on toxin-positive whole stool samples. A retrospective chart review was performed on all patients with a positive toxin assay. Sixteen of 150 patients (10.7%) had toxigenic C. difficile colonization (CDC) on admission. The overall incidence of CDI within 100 days after HSCT was 24.7% (37 of 150). The median time to diagnosis of CDI was 3.5 days after HSCT. In an adjusted logistic regression model, CDC on admission was a significant risk factor for CDI (odds ratio, 68.5; 95% confidence interval, 11.4 to 416.2). MLST on 22 unit patient toxin-positive stool specimens revealed 15 distinct strain types. Further analysis identified at least 1 potential cross-transmission event; some events may have been missed because of incomplete typing from other specimens. Despite aggressive infection control interventions, there was no decline in the number of CDI cases during the study period. These data suggest that prior CDC plays a major role in CDI rates in this high-risk patient population. It remains unclear if CDI was cross-transmitted in the unit.

Community-acquired Clostridium difficile infection: an increasing public health threat

There has been a startling shift in the epidemiology of Clostridium difficile infection over the last decade worldwide, and it is now increasingly recognized as a cause of diarrhea in the community. Classically considered a hospital-acquired infection, it has now emerged in populations previously considered to be low-risk and lacking the traditional risk factors for C. difficile infection, such as increased age, hospitalization, and antibiotic exposure. Recent studies have demonstrated great genetic diversity for C. difficile, pointing toward diverse sources and a fluid genome. Environmental sources like food, water, and animals may play an important role in these infections, apart from the role symptomatic patients and asymptomatic carriers play in spore dispersal. Prospective strain typing using highly discriminatory techniques is a possible way to explore the suspected diverse sources of C. difficile infection in the community. Patients with community-acquired C. difficile infection do not necessarily have a good outcome and clinicians should be aware of factors that predict worse outcomes in order to prevent them. This article summarizes the emerging epidemiology, risk factors, and outcomes for community-acquired C. difficile infection.

Diagnosis of Clostridium difficile infection: an ongoing conundrum for clinicians and for clinical laboratories

Clostridium difficile is a formidable nosocomial and community-acquired pathogen, causing clinical presentations ranging from asymptomatic colonization to self-limiting diarrhea to toxic megacolon and fulminant colitis. Since the early 2000s, the incidence of C. difficile disease has increased dramatically, and this is thought to be due to the emergence of new strain types. For many years, the mainstay of C. difficile disease diagnosis was enzyme immunoassays for detection of the C. difficile toxin(s), although it is now generally accepted that these assays lack sensitivity. A number of molecular assays are commercially available for the detection of C. difficile. This review covers the history and biology of C. difficile and provides an in-depth discussion of the laboratory methods used for the diagnosis of C. difficile infection (CDI). In addition, strain typing methods for C. difficile and the evolving epidemiology of colonization and infection with this organism are discussed. Finally, considerations for diagnosing C. difficile disease in special patient populations, such as children, oncology patients, transplant patients, and patients with inflammatory bowel disease, are described. As detection of C. difficile in clinical specimens does not always equate with disease, the diagnosis of C. difficile infection continues to be a challenge for both laboratories and clinicians.

Clostridium difficile infection after adult autologous stem cell transplantation: a multicenter study of epidemiology and risk factors

We sought to describe the epidemiology of Clostridium difficile infection (CDI) among adult recipients of autologous hematopoietic stem cell transplantation (auto-HSCT) within the first year after HSCT in centers with variable epidemiology of hypertoxigenic strains. A multicenter, retrospective nested case-control study was conducted among 873 auto-HSCT recipients at Johns Hopkins Hospital (JHH) and Hôpital Maisonneuve-Rosemont (HMR) between January 2003 and December 2008. Despite center differences in the prevalence of NAP-1 strains during the study period (21% to 43% at JHH versus 80% to 84% in HMR), the 1-year incidence of CDI was similar in the 2 hospitals (6.2% at JHH versus 5.7% at HMR). The median time to infection was 11 days (interquartile range, 1 to 27 days). In case-control analyses, grade ≥2 mucositis (odds ratio [OR], 3.00; P = .02) and receipt of a fourth-generation cephalosporin (OR, 2.76; P = .04) were identified as predictors for CDI. Mucositis was the strongest predictor of risk for CDI in multivariate analysis (adjusted OR, 2.77; P = .03). CDI is a common and early complication of auto-HSCT. Treatment-related gastrointestinal mucosal damage, along with the potentially modifiable risk of antimicrobial exposure, influence the risk for CDI early after auto-HSCT.

Fidaxomicin versus conventional antimicrobial therapy in 59 recipients of solid organ and hematopoietic stem cell transplantation with Clostridium difficile-associated diarrhea

The feasibility of fidaxomicin versus vancomycin and metronidazole (conventional therapy) was assessed in 59 transplant recipients with 61 episodes of Clostridium difficile-associated diarrhea (CDAD). Overall clinical cure was achieved in 86% of episodes, and in 7% of episodes, infection recurred. Fidaxomicin was well tolerated. Clinical cures were not significantly different compared with conventional therapy (67% versus 89%, respectively; P = 0.06). Univariate analysis of predictors for lack of clinical cure included continued use of broad-spectrum systemic antibiotics (P = 0.026) and prior diagnosis of CDAD (95% confidence interval, 1.113 to 19.569; odds ratio, 4.667; P = 0.041). New-onset vancomycin-resistant Enterococcus (VRE) colonization was not noted after fidaxomicin therapy alone. However, this occurred in 10 of 28 patients (36%) following conventional therapy, and 2 of 3 patients with subsequent bacteremia died.

A retrospective review of metronidazole and vancomycin in the management of Clostridium difficile infection in patients with hematologic malignancies

Background

The incidence and severity of Clostridium difficile infection has significantly increased over the past decade. Although the epidemiology and treatment of C. difficile infection is well elucidated in the non-oncology population, it is poorly understood among cancer patients. This illustrates great concern as the majority of these patients are immunosuppressed, which puts them at higher risk for developing severe disease. Furthermore, suboptimal treatment of C. difficile infection can compromise care of underlying malignancy. Due to limited amount of data, we conducted this study to better ascertain the epidemiology and treatment outcomes of C. difficile infection in a subset of oncology patients at our institution.

Objectives

The primary objective was to assess the incidence and severity of C. difficile infection in patients with hematologic malignancies, including those undergoing hematopoietic stem cell transplant for a hematologic condition. The secondary objectives were to assess: (a) the outcome of C. difficile infection after therapy with metronidazole and/or vancomycin and (b) mortality following C. difficile infection.

Methods

We performed a retrospective study to assess the incidence and severity of C. difficile infection and to evaluate outcomes of therapy with metronidazole and/or vancomycin among adult patients admitted to the Malignant Hematology/Blood and Marrow Transplantation service at our center from January 2009 to 2012.

Results

Of the 390 admitted patients during the 3-year study period, the overall incidence of C. difficile infection was 18.7% ( n = 73). Forty-six patients (63.0%) were deemed to have mild-moderate C. difficile infection. With regards to outcome of therapy, less exposure to antimicrobial agents was significantly associated with a higher resolution rate ( p = 0.0029). Response rates to metronidazole were 53.7%, vancomycin 50%, and combination therapy 38.5%, although no difference in achievement of resolution was found among the three treatment modalities ( p = 0.5533). Older patients were more likely to experience recurrent C. difficile infection ( p = 0.0007). It was found that 55 patients (75.3%) were alive at 6 months.

Conclusions

These results highlight the high incidence of C. difficile infection in a subset of cancer patients at our institution. Although most patients presented with mild-moderate disease, severity of C. difficile infection in cancer patients may be underestimated due to the frequent presence of neutropenia. This study is the first analysis conducted, which directly compares outcomes of C. difficile infection after therapy with metronidazole, vancomycin, or combination therapy exclusively in patients with hematologic malignancies, including those undergoing hematopoietic stem cell transplant for a hematologic condition. We found no difference in treatment outcomes among metronidazole, vancomycin, or combination therapy. The recommendation from the literature to use metronidazole as the initial drug of choice for mild-moderate C. difficile infection is a reasonable option, although the rate of cure is low. This study highlights the critical need for better treatment options, due to suboptimal response rates to current therapy. Larger scale studies are needed to better understand the epidemiology and management of C. difficile infection in this patient population.

Epidemiology, risk factors, and outcomes of Clostridium difficile infection in kidney transplant recipients

BACKGROUND

We sought to describe the epidemiology and risk factors for Clostridium difficile infection (CDI) among kidney transplant recipients (KTR) between 1 January 2008 and 31 December 2010.

METHODS

A single-institution retrospective study was conducted among all adult KTR with CDI, defined as a positive test for C. difficile by a cell cytotoxic assay for C. difficile toxin A or B or polymerase chain reaction test for toxigenic C. difficile.

RESULTS

Among 603 kidney transplants performed between 1 January 2008 and 31 December 2010, 37 (6.1%) patients developed CDI: 12 (of 128; 9.4%) high-risk (blood group incompatible and/or anti-human leukocyte antigen donor-specific antibodies) vs. 25 (of 475; 5.3%, P = 0.08) standard-risk patients. The overall rate of CDI increased from 3.7% in 2008 to 9.4% in 2010 (P = 0.05). The median time to CDI diagnosis was 9 days, with 27 (73.0%) patients developing CDI within the first 30 days after their transplant, and 14 (51.8%) developing CDI within 7 days. A case-control analysis of 37 CDI cases and 74 matched controls demonstrated the following predictors for CDI among KTR: vancomycin-resistant Enterococcus colonization before transplant (odds ratio [OR]: 3.6, P = 0.03), receipt of an organ from Centers for Disease Control high-risk donor (OR: 5.9, P = 0.006), and administration of high-risk antibiotics within 30 days post transplant (OR: 6.6, P = 0.001).

CONCLUSIONS

CDI remains a common early complication in KTR, with rates steadily increasing during the study period. Host and transplant-related factors and exposure to antibiotics appeared to significantly impact the risk for CDI among KTR.

Fecal microbiota transplantation for fulminant Clostridium difficile infection in an allogeneic stem cell transplant patient

We present a case of severe Clostridium difficile infection (CDI) in a non-neutropenic allogeneic hematopoietic stem cell transplant recipient who was treated successfully with fecal microbiota therapy after standard pharmacologic therapy had failed. Following naso-jejunal instillation of donor stool, the patient's symptoms resolved within 48 h. Bowel resection was averted. This is the first case in the literature, to our knowledge, to describe fecal microbiota therapy in a profoundly immunocompromised host with severe CDI. We propose that fecal microbiota therapy be considered as a therapeutic option in immunosuppressed patients with refractory severe CDI.

Hospital-onset Clostridium difficile infection rates in persons with cancer or hematopoietic stem cell transplant: a C3IC network report

A multicenter survey of 11 cancer centers was performed to determine the rate of hospital-onset Clostridium difficile infection (HO-CDI) and surveillance practices. Pooled rates of HO-CDI in patients with cancer were twice the rates reported for all US patients (15.8 vs 7.4 per 10,000 patient-days). Rates were elevated regardless of diagnostic test used.

Epidemiological features of Clostridium difficile infection among inpatients at Hamad General Hospital in the state of Qatar, 2006-2009

The aim of this retrospective study was to evaluate the epidemiology, clinical course and outcome of Clostridium difficile infection among inpatients at Hamad General Hospital in Qatar, from 2006 to 2009. During this period, 123 patients were diagnosed with C. difficile infection and the overall incidence was 1.6/10,000 patient days. The mean age (±SD) of patients was 50.9 ± 21.2 years. The most frequent underlying disease was hypertension 51/123 (41.5%) and 133 prescriptions of antimicrobials were ordered for 105/123 (86.1%) patients prior to C. difficile infection with piperacillin-tazobactam being the most frequently prescribed antimicrobial 39/131 (29.7%). Nosocomial infection was found in 101/123 (82.0%) of cases, and the most common clinical feature was watery diarrhoea 119/123 (96.7%). Antimicrobials were discontinued in 53/105 (50.5%) cases and 118/123 (95.9%) of them received metronidazole as the initial treatment. The mean treatment duration (±SD) was 9.08 ± 5.6 days. Fifteen (12.7%) patients failed the first course of antimicrobial therapy, of which four were treated with oral vancomycin, and eleven patients received both drugs. Recurrence of infection was observed in 12/118 (10.2%) patients and 30-day mortality was 38/123 (30.9%). Several clinical variables were associated with increased 30-day mortality on univariate analysis. Only occurrence of disease among Qataris, prolonged hospitalisation, positive stool occult blood test, high white blood cells and septic shock were found to be independent predictors of mortality by multivariate logistic regression analysis. In conclusion, C. difficile infection was a recognise cause of morbidity and mortality in our hospital with low and stable incidence. It involved predominantly patients younger than 65 years with underlying illness and metronidazole and vancomycin were effective in resolving symptoms in the majority of our patients.

Nosocomial diarrhea: evaluation and treatment of causes other than Clostridium difficile

Diarrhea is common among hospitalized patients but the causes are distinct from those of diarrhea in the community. We review existing data about the epidemiology of nosocomial diarrhea and summarize recent progress in understanding the mechanisms of diarrhea. Clinicians should recognize that most cases of nosocomial diarrhea have a noninfectious etiology, including medications, underlying illness, and enteral feeding. Apart from Clostridium difficile, the frequency of infectious causes such as norovirus and toxigenic strains of Clostridium perfringens, Klebsiella oxytoca, Staphylococcus aureus, and Bacteroides fragilis remains largely undefined and test availability is limited. Here we provide a practical approach to the evaluation and management of nosocomial diarrhea when tests for C. difficile are negative.

Epidemiology and outcomes of Clostridium difficile infections in hematopoietic stem cell transplant recipients

Background. Clostridium difficile is the leading cause of infectious diarrhea among hospitalized patients and is a major concern for patients undergoing hematopoietic stem cell transplantation (HSCT). Risk factors and the natural history of C. difficile infection (CDI) are poorly understood in this population. Methods. We performed a retrospective nested case-control study to describe the epidemiology, timing, and risk factors for CDI among adult patients who received HSCTs at our center from January 2003 through December 2008. Results. The overall 1-year incidence of CDI was 9.2% among HSCTs performed (n = 999). The median time to diagnosis of CDI was short among both autologous and allogeneic HSCT recipients (6.5 days and 33 days, respectively). Risk factors for CDI in allogeneic HSCT recipients included receipt of chemotherapy prior to conditioning for HSCT, broad-spectrum antimicrobial use, and acute graft-versus-host disease (GVHD; adjusted odds ratio [AOR], 4.45; 95% confidence interval [CI], 1.54-12.84; P = .006). There was a strong relationship between early CDI and subsequent development of gastrointestinal tract GVHD in the year following allogeneic HSCT (P < .001). Gastrointestinal GVHD was also strongly associated with an increased risk for recurrent CDI (AOR, 4.23 [95% CI, 1.20-14.86]; P = .02). Conclusions. These results highlight the high incidence and early timing of CDI after HSCT. Early timing, coupled with the noted risk of pretransplant chemotherapy, suggests that the natural history of disease in some patients may involve colonization prior to HSCT. A potentially important interplay between CDI and GVHD involving the gastrointestinal tract was observed.

Clostridium difficile infection after allogeneic hematopoietic stem cell transplantation: incidence, risk factors, and outcome

Clostridium difficile (C. difficile) infection was observed in 13% of recipients after hematopoietic stem cell transplantation (HSCT), mainly in the first month posttransplantation. Risk factors were cord blood as the source of stem cells, acute graft-versus-host disease (GVHD), and total body irradiation (TBI). No association was found with an increased risk of mortality. The purpose of this study was to evaluate the incidence, risk factors, and outcome of C. difficile infection (CDI) after HSCT. We conducted a single-center, retrospective, cohort study on all patients who received an allogeneic HSCT from January 2004 to December 2007. All patients with diarrhea in the first year after HSCT were tested for the presence of C. difficile in stools. Among the 407 assessable patients, 53 presented at least 1 CDI in the first year post-HSCT. The total incidence rate was 5.6 cases of CDI per 10,000 patient-days. Fifty percent of cases were diagnosed in the first month after HSCT, and 95% occurred during the first 6 months. Fewer than 5% of patients with CDI had severe diarrhea and severe complications were never observed. TBI in the conditioning regimen, cord blood as the source of stem cells, and acute graft-versus-host disease (aGVHD) were independently associated with CDI. Six patients (11%) had a recurrence of CDI. Four patients required second-line treatment with vancomycin. With a median follow-up of 22 months, the 2-year overall survival rates were similar between patients who presented a CDI and those who did not. CDI was observed in approximately 13% of recipients after HSCT, mainly in the first month posttransplantation and was associated with CB, aGVHD, and TBI. CDI was not associated either with severe complications or with an increased risk of mortality in this large cohort of patients.

Management of gram-positive bacterial infections in patients with cancer

Bacterial infections, particularly those due to gram-positive bacteria, continue to predominate in patients with cancer. Coagulase-negative and coagulase-positive staphylococci and enterococci remain as common pathogenic microorganisms. Clostridium difficile has emerged as a significant pathogen. Major clinical syndromes include vascular catheter-related infection, febrile neutropenia, diarrhea and colitis. Rising antimicrobial resistance among gram-positive bacteria is of serious concern. The clinical utility of penicillin against streptococci and vancomycin against coagulase-negative and coagulase-positive staphylococci and enterococci may be rapidly diminishing. Liberal empiric use of vancomycin during neutropenic fever needs careful reconsideration. Newer promising anti-gram-positive bacterial drugs with activity against methicillin-resistant staphylococci include daptomycin, linezolid, tigecycline and telavancin. However, toxicity concerns, limited data in immunocompromised populations and high cost prevent the widespread use of these drugs among patients with cancer.

Clostridium difficile infection in non-HIV-immunocompromised patients and in HIV-infected patients

Clostridium difficile infection is a common cause of morbidity in patients with HIV infection and in patients with non-HIV immune deficiency. The frequency of C. difficile--associated diarrhea (CDAD) seen in these two patient populations has been attributed to immune deficiency, as well as to increased exposure to hospital environments and antibiotic therapy, both of which are major risk factors for CDAD. This article reviews recent data useful in the evaluation, treatment, and prevention of C. difficile infection in these patient groups. Recent publications relating to C. difficile infection in specific immunocompromised conditions are also discussed.

Epidemiology and risk factors for Clostridium difficile infection in children

BACKGROUND

Pediatric Clostridium difficile infection (CDI)-related hospitalizations are increasing. We sought to describe the epidemiology of pediatric CDI at a quaternary care hospital.

METHODS

Nested case-control study within a cohort of children <18 years tested for C. difficile between January and August 2008. The study included patients who were ≥ 1 year with a positive test and diarrhea; those without diarrhea (ie, presumed colonization) were excluded. Two unmatched controls per case were randomly selected from patients ≥ 1 year with a negative test. Potential predictors of CDI included age, gender, comorbidities, prior hospitalization, receipt of C. difficile-active antibiotics in the prior 24 hours, and recent (≤ 4 weeks) exposure to antibiotics or acid-blocking medications. Multivariate logistic regression models were created to identify independent predictors of CDI.

RESULTS

Of 1891 tests performed, 263 (14%) were positive in 181 children. Ninety-five patients ≥ 1 year with CDI were compared with 238 controls. In multivariate analyses, predictors of CDI included solid organ transplant (odds ratio [OR], 8.09; 95% confidence interval [CI], 2.10-31.12), lack of prior hospitalization (OR, 8.43; 95% CI, 4.39-16.20), presence of gastrostomy or jejunostomy (G or J) tube (OR, 3.32; 95% CI 1.71-6.42), and receipt of fluoroquinolones (OR, 17.04; 95% CI, 5.86-49.54) or nonquinolone antibiotics (OR, 2.23; 95% CI, 1.18-4.20) in the past 4 weeks. Receipt of C. difficile-active antibiotics within 24 hours before testing was associated with a lower odds of CDI (OR, 0.22; 95% CI, 0.09-0.58).

CONCLUSIONS

Recent antibiotic exposure and certain comorbid conditions (solid organ transplant, presence of a gastrostomy or jejunostomy tube) were associated with CDI. Diagnostic testing has less utility in patients being treated with C. difficile-active antibiotics.

Clostridium difficile infection in hospitalized children in the United States

OBJECTIVES

To evaluate the trend in Clostridium difficile infection (CDI) among hospitalized children in the United States and to evaluate the severity of and risk factors associated with these cases of CDI.

DESIGN

A retrospective cohort study using the triennial Healthcare Cost and Utilization Project Kids' Inpatient Database for the years 1997, 2000, 2003, and 2006.

SETTING

Hospitalized children in the United States.

PARTICIPANTS

A nationally weighted number of patients (10 474 454) discharged from the hospital, 21 274 of whom had CDI.

MAIN EXPOSURE

Discharge diagnosis of CDI.

MAIN OUTCOME MEASURES

Trend in cases of CDI; effect and severity were measured by length of hospital stay, hospitalization charges, colectomy rate, and death rate.

RESULTS

There was an increasing trend in cases of CDI, from 3565 cases in 1997 to 7779 cases in 2006 (P < .001). Patients with CDI had an increased risk of death (adjusted odds ratio [OR], 1.20; 95% confidence interval [95% CI], 1.01-1.43), colectomy (adjusted OR, 1.36; 95% CI, 1.04-1.79), a longer length of hospital stay (adjusted OR, 4.34; 95% CI, 3.97-4.83), and higher hospitalization charges (adjusted OR, 2.12; 95% CI, 1.98-2.26). There was no trend in death, colectomy, length of hospital stay, or hospitalization charges during the 4 time periods (ie, 1997, 2000, 2003, and 2006). The risk of comorbid diagnoses associated with CDI included inflammatory bowel disease, with an OR of 11.42 (95% CI, 10.16-12.83), and other comorbid diagnoses associated with immunosuppression or antibiotic administration.

CONCLUSIONS

There is an increasing trend in CDI among hospitalized children, and this disease is having a significant effect on these children. In contrast to adults, there is no increasing trend in the severity of CDI in children. Children with medical conditions (including inflammatory bowel disease and immunosuppression) or conditions requiring antibiotic administration are at high risk of CDI.

Clostridium difficile infection in cancer patients and hematopoietic stem cell transplant recipients

Clostridium difficile has become the most common bacterial cause of nosocomial diarrhea. High rates of C. difficile infection (CDI) coupled with increasing morbidity and mortality attributed to CDI have sparked a renewed interest in this disease. Emergence of hypervirulent strains, rising rates of severe and recurrent infection and associated infection control challenges, and diagnostic and therapeutic dilemmas are major issues in the non-oncology population. Scant data on CDI exist in the cancer/transplant population. The purpose of this article is to describe the epidemiology, pathogenesis and management of CDI in patients receiving cancer chemotherapeutic agents, and in hematopoietic stem cell transplant recipients.

Recent epidemiology of Clostridium difficile infection during hematopoietic stem cell transplantation

Given the limited information on Clostridium difficile infection (CDI) during hematopoietic stem cell transplantation (HSCT), we examined the recent epidemiology of CDI in HSCT recipients at our institution. During the two-yr retrospective study period (2005-2006), 361 transplants were performed: 60% allogeneic and 40% autologous. Among all hospitalized patients in a non-outbreak setting, CDI rates in HSCT recipients were ninefold higher than those in general patients and 1.4-fold higher than those in patients with cancer (24.0 vs. 2.6 vs. 16.8/10,000 patient-days respectively). Sixty-two episodes of CDI occurred in 51 (14%) HSCT recipients: 39 (18%) allogeneic vs. 12 (8%) autologous (p = 0.01). Almost half of CDI episodes occurred within 30 d post-HSCT and 22% before HSCT. Clostridium difficile toxin assay was initially positive in 28% of the first, 31% of the second and 27% of the third stool samples tested. All but one patient responded to therapy with metronidazole or vancomycin. Severe CDI occurred in one patient and recurrent CDI in two patients. CDI is common during HSCT especially in allogeneic transplants during the peri-HSCT period. Prospective studies to better define the epidemiology and identify unique risk factors for CDI and more accurate tests to confirm the diagnosis in this population are needed.