Work-up for infectious diarrhea after allogeneic hematopoietic stem cell transplantation: single specimen testing results in cost savings without compromising diagnostic yield

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

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

Infectious diarrhea after allogeneic hematopoietic cell transplantation assessed by a multiplex polymerase chain reaction assay

OBJECTIVES

To determine the incidence of infectious diarrhea after allogeneic hematopoietic cell transplantation (HCT) using a multiplex polymerase chain reaction assay and assess risk factors for developing infectious diarrhea.

METHODS

This was a single-center retrospective study of 140 consecutive allogeneic HCT recipients. Infectious diarrhea was assessed using a laboratory-developed multiplex polymerase chain reaction the first year after transplantation.

RESULTS

The incidence rate of infectious diarrhea episodes was 47 per 100 person-years, with the highest rate observed in the pre-engraftment phase. Most episodes were seen as nosocomial infections (38%) and most affected patients (82%) had only one episode of infectious diarrhea. The cumulative incidence of at least one episode of infectious diarrhea was 32% after 1 year. Nonrelapse mortality was higher in transplant recipients with at least one episode of infectious diarrhea (hazard ratio (HR) 2.02, 95% CI = 1.07-3.80). The most frequently observed pathogens were Clostridium difficile, adenovirus, Enteropathogenic Escherichia coli, and Campylobacter jejuni. Patients with acute lower gastrointestinal graft-vs-host disease stage 3 or 4 (HR 3.68, 95% CI = 1.57-8.63) conferred a higher risk for a first infectious diarrhea episode.

CONCLUSION

Infectious diarrhea after allogeneic HCT was seen in about one-third of the patients, mostly as nosocomial infection in the pre-engraftment phase.

Infection prevention requirements for the medical care of immunosuppressed patients: recommendations of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute

In Germany, guidelines for hygiene in hospitals are given in form of recommendations by the Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention, "KRINKO"). The KRINKO and its voluntary work are legitimized by the mandate according to § 23 of the Infection Protection Act (Infektionsschutzgesetz, "IfSG"). The original German version of this document was published in February 2021 and has now been made available to the international professional public in English. The guideline provides recommendations on infection prevention and control for immunocompromised individuals in health care facilities. This recommendation addresses not only measures related to direct medical care of immunocompromised patients, but also management aspects such as surveillance, screening, antibiotic stewardship, and technical/structural aspects such as patient rooms, air quality, and special measures during renovations.

Diarrhea in pediatric recipients of solid organ or bone marrow transplants

Diarrhea is common in adults after solid organ transplantation (SOT) and bone marrow transplantation (BMT), but data in children are limited. Therefore, we aimed to determine the incidence and etiology of pediatric early-onset diarrhea in post SOT and BMT.We reviewed children aged 6 months to 18 years who underwent liver transplantation, kidney transplantation or BMT between January 2015 and December 2019 with duration of diarrhea > 72 hours within the first 6 months after transplantation. Clinical data and diarrheal course were collected. Regression analyses were performed to define factors associated with the interested outcomes.Among 252 transplanted patients, 168 patients (66.6%) had 289 documented episodes of diarrhea. A diagnosis of 68.2% of post-transplant diarrhea remained 'indefinite'. Enteric infection in SOT and gastrointestinal acute graft-versus-host disease (GI-aGVHD) in BMT were the commonly identified etiologies. Among 182 episodes among BMT children, skin rash was more pronounced when compared the ones with diarrhea > 7 days vs ≤ 7 days (odds ratio [OR] 13.9; 95% CI 1.8, 107.6). Males were more likely to develop GI-aGVHD as compared to females (OR 8.9). We found that GI-aGVHD was more common in the ones with skin rash and the presence of white blood cells in stool examination (OR 8.4 and 3.1, respectively). Deaths occurred in 7.7%.Two-thirds of post-transplant children experienced at least one episode of early-onset diarrhea, of which the etiology mainly remains undefined. Various clinical factors of prolonged/chronic diarrhea and GI-aGVHD may help clinicians when managing these children.

Impact of a Multiplexed Polymerase Chain Reaction Panel on Identifying Diarrheal Pathogens in Hematopoietic Cell Transplant Recipients

BACKGROUND

Diarrhea is common and associated with substantial morbidity among hematopoietic cell transplant (HCT) recipients, but the etiology is often not identified. Multiplexed polymerase chain reaction (PCR) assays increase the detection of diarrheal pathogens, but the impact of this technology in this population has not been evaluated.

METHODS

Our center replaced stool cultures and other conventional microbiologic methods with the FilmArray Gastrointestinal Panel (GI PCR) in June 2016. We reviewed all adult patients who received an HCT from June 2014-May 2015 (pre-GI PCR, n = 163) and from June 2016-May 2017 (post-GI PCR, n = 182) and followed them for 1 year after transplantation. Clostridioides difficile infection was diagnosed by an independent PCR test in both cohorts.

RESULTS

The proportion of patients with ≥1 identified infectious diarrheal pathogen increased from 25% to 37% after implementation of GI PCR (P = .01). Eight patients (5%) in the pre-GI PCR cohort tested positive for a pathogen other than C. difficile versus 49 patients (27%) in the post-GI PCR cohort (P < .001). The most common non-C. difficile diarrheal pathogens in the post-GI PCR cohort were enteropathogenic Escherichia coli (n = 14, 8%), norovirus (n = 14, 8%), and Yersinia enterocolitica (n = 7, 4%). The percentage of diarrheal episodes with an identified infectious etiology increased from 14% to 23% (P = .001). Median total costs of stool testing per patient did not increase (pre: $473; post: $425; P = .25).

CONCLUSIONS

Infectious etiologies of diarrhea were identified in a higher proportion of HCT recipients after replacing conventional stool testing with a multiplexed PCR assay, without an increase in testing costs.

Diarrheal Morbidity During Hematopoietic Cell Transplantation: The Diagnostic Yield of Stool Cultures

INTRODUCTION

Diarrhea affects a significant proportion of patients undergoing hematopoietic cell transplantation (HCT). We explored the diagnostic yield of stool cultures for enteric pathogens among patients undergoing HCT.

METHODS

This is a single-center, retrospective study. Between 5/2007 and 4/2020, consecutive patients who underwent HCT were included if inpatient bacterial stool cultures were collected. Patient characteristics, results, and timing of stool cultures obtained during hospitalization were collected.

RESULTS

A total of 1072 individuals underwent autologous (n = 603) and allogeneic (n = 469) HCT. Overall, 947 stool culture samples were obtained from 561 (52%) patients with diarrheal illness during hospitalization for HCT. Most (99%) samples were obtained beyond 3 days of admission, mainly (77%) during neutropenia. Overall, only four (0.42%) (autologous, n = 3; allogeneic, n = 1) patients had a positive stool culture and in all cases Campylobacter spp. were the pathogens identified. The number of stool cultures needed-to-test to diagnose one case of bacterial infection was 237. The cost of diagnosing one case of bacterial diarrhea was US $8770. Patients with a positive stool culture did not have discerning characteristics.

CONCLUSIONS

In our experience, the yield of stool cultures for enteropathogens in patients undergoing HCT is extremely low and thus should be avoided in most cases.

Newer approaches in diagnosis of diarrhea in immunocompromised patients

PURPOSE OF REVIEW

This review will focus on the epidemiology and cause of diarrheal illness in solid organ transplant and stem-cell transplant population recipients with a specific focus on the role of advanced multiplex technology in the diagnosis of diarrhea within this patient population.

RECENT FINDINGS

A wide range of infectious and noninfectious causes of diarrhea have been described in immunocompromised patients. The most common infections noted are Clostridioides difficile, norovirus, and cytomegalovirus, whereas immunosuppressive drugs and mucositis are the most common noninfectious causes of diarrhea. Historically, diagnostic evaluation has been limited to an array of single pathogen assays. Newer multiplex assays have become available that allow rapid, sensitive detection of a wide range of pathogens in a single assay. These assays have improved the number of patients with a diagnosed pathogen but may identify colonizing pathogens that are not pathogenic. Studies are needed to inform the discrimination and optimal use of these newer assays.

SUMMARY

Diarrhea is a common complication in immunocompromised patients and is associated with greater morbidity and rare mortality. New diagnostics facilitate detection of recognized pathogens and may allow for improved outcomes through the use of pathogen-targeted therapy.

Diagnosis and management of diarrhea in solid-organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of diarrhea in the pre- and post-transplant period. Diarrhea in an organ transplant recipient may result in significant morbidity including dehydration, increased toxicity of medications, and rejection. Transplant recipients are affected by a wide range of etiologies of diarrhea with the most common causes being Clostridioides (formerly Clostridium) difficile infection, cytomegalovirus, and norovirus. Other bacterial, viral, and parasitic causes can result in diarrhea but are far less common. Further, noninfectious causes including medication toxicity, inflammatory bowel disease, post-transplant lymphoproliferative disease, and malignancy can also result in diarrhea in the transplant population. Management of diarrhea in this population is directed at the cause of the diarrhea, instituting therapy where appropriate and maintaining proper hydration. Identification of the cause to the diarrhea needs to be timely and focused.

Impacts and Challenges of Advanced Diagnostic Assays for Transplant Infectious Diseases

The advanced technologies described in this chapter should allow for full inventories to be made of bacterial genes, their time- and place-dependent expression, and the resulting proteins as well as their outcome metabolites. The evolution of these molecular technologies will continue, not only in the microbial pathogens but also in the context of host-pathogen interactions targeting human genomics and transcriptomics. Their performance characteristics and limitations must be clearly understood by both laboratory personnel and clinicians to ensure proper utilization and interpretation.

Rotavirus Infection in Pediatric Allogeneic Hematopoietic Cell Transplant Recipients: Clinical Course and Experience Using Nitazoxanide and Enterally Administered Immunoglobulins

BACKGROUND

Rotaviruses may produce prolonged and severe disease in allogeneic hematopoietic cell transplant (HCT) recipients. Nitazoxanide and enterally administered human immunoglobulins are potential therapeutic options. This retrospective study describes the clinical course of rotavirus infection in pediatric allogeneic HCT recipients and a single-center experience with nitazoxanide and oral immunoglobulins as potential treatment options.

METHODS

We identified 36 patients who had positive stool rotavirus antigen assays after allogeneic HCT from May 30, 2012, to July 31, 2015. Clinical, microbiologic and treatment data were collected and analyzed using descriptive statistics.

RESULTS

Forty-nine discrete episodes of rotavirus infection were identified among these 36 patients for a cumulative incidence of 19.7%. For these 49 episodes, the median day to infection after HCT was day 82, and the median duration of diarrhea was 17.5 days (range 4-122). Nitazoxanide and enteral immunoglobulins were prescribed for 41 episodes. The median duration of clinical symptoms after initiation of nitazoxanide was 11 days (range 2-85), 23 days (range 10-107) after enteral immunoglobulins and 26 days (range 6-90) after a combination of nitazoxanide and enteral immunoglobulins (P = 0.1). No adverse effects of either treatment were documented, but efficacy could not be assessed in this patient population.

CONCLUSIONS

In pediatric HCT recipients, the clinical illness produced by rotaviruses is prolonged compared with otherwise healthy children. Nitazoxanide appears safe, but its efficacy for this indication requires further study.

Diagnosis and management of gastrointestinal complications in adult cancer patients: 2017 updated evidence-based guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Cancer patients frequently suffer from gastrointestinal complications. In this manuscript, we update our 2013 guideline on the diagnosis and management of gastrointestinal complications in adult cancer patients by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO). An expert group was put together by the AGIHO to update the existing guideline. For each sub-topic, a literature search was performed in PubMed, Medline, and Cochrane databases, and strengths of recommendation and the quality of the published evidence for major therapeutic strategies were categorized using the 2015 European Society for Clinical Microbiology and Infectious Diseases (ESCMID) criteria. Final recommendations were approved by the AGIHO plenary conference. Recommendations were made with respect to non-infectious and infectious gastrointestinal complications. Strengths of recommendation and levels of evidence are presented. A multidisciplinary approach to the diagnosis and management of gastrointestinal complications in cancer patients is mandatory. Evidence-based recommendations are provided in this updated guideline.

Acute graft-versus-host disease of the gut: considerations for the gastroenterologist

Haematopoietic stem cell transplantation (HSCT) is central to the management of many haematological disorders. A frequent complication of HSCT is acute graft-versus-host disease (GVHD), a condition in which immune cells from the donor attack healthy recipient tissues. The gastrointestinal system is among the most common sites affected by acute GVHD, and severe manifestations of acute GVHD of the gut portends a poor prognosis in patients after HSCT. Acute GVHD of the gastrointestinal tract presents both diagnostic and therapeutic challenges. Although the clinical manifestations are nonspecific and overlap with those of infection and drug toxicity, diagnosis is ultimately based on clinical criteria. As reliable serum biomarkers have not yet been validated outside of clinical trials, endoscopic and histopathological evaluation continue to be utilized in diagnosis. Once a diagnosis of gastrointestinal acute GVHD is established, therapy with systemic corticosteroids is typically initiated, and non-responders can be treated with a wide range of second-line therapies. In addition to treating the underlying disease, the management of complications including profuse diarrhoea, severe malnutrition and gastrointestinal bleeding is paramount. In this Review, we discuss strategies for the diagnosis and management of acute GVHD of the gastrointestinal tract as they pertain to the practising gastroenterologist.

Diarrhea after allogeneic stem cell transplantation: beyond graft-versus-host disease

Diarrhea constitutes a frequent and often debilitating complication of allogeneic hematopoietic cell transplantation (alloHCT). Especially when accompanied by jaundice, skin rash, and symptoms of the upper gastrointestinal tract, diarrhea strongly suggests emergence of acute graft-versus-host disease (GvHD), which is a serious immune complication of the procedure, with possible fatal consequences. However, especially when diarrhea occurs as an isolated symptom, the other causes must be excluded before initiation of GvHD treatment with immune-suppressive drugs. In this article, a broad overview of the literature of different causes of diarrhea in the setting of alloHCT is provided, revealing causes and presentations different from those observed in the general population. We discuss gastrointestinal GvHD with a special focus on biomarkers, but also uncover underlying infectious: viral, bacterial, and parasitic as well as toxic causes of diarrhea. Finally, we suggest a practical algorithm of approach to patients with diarrhea after alloHCT, which may help to establish a proper diagnosis and initiate a causative treatment.

Infection Prevention in Transplantation

The number of patients undergoing hematopoietic cell and solid organ transplantation are increasing every year, as are the number of centers both transplanting and caring for these patients. Improvements in transplant procedures, immunosuppressive regimens, and prevention of transplant-associated complications have led to marked improvements in survival in both populations. Infections remain one of the most important sources of excess morbidity and mortality in transplant, and therefore, infection prevention strategies are a critical element for avoiding these complications in centers caring for high-risk patients. This manuscript aims to provide an update of recent data on prevention of major healthcare-associated infections unique to transplantation, reviews the emergence of antimicrobial resistant infections, and discusses updated strategies to both identify and prevent transmission of these pathogens in transplant recipients.

Noroviruses as a Cause of Diarrhea in Immunocompromised Pediatric Hematopoietic Stem Cell and Solid Organ Transplant Recipients

Case reports describe significant norovirus gastroenteritis morbidity in immunocompromised patients. We evaluated norovirus pathogenesis in prospectively enrolled solid organ (SOT) and hematopoietic stem cell transplant (HSCT) patients with diarrhea who presented to Texas Children's Hospital and submitted stool for enteric testing. Noroviruses were detected by real-time reverse transcription polymerase chain reaction. Clinical outcomes of norovirus diarrhea and non-norovirus diarrhea patients, matched by transplanted organ type, were compared. Norovirus infection was identified in 25 (22%) of 116 patients, more frequently than other enteropathogens. Fifty percent of norovirus patients experienced diarrhea lasting ≥14 days, with median duration of 12.5 days (range 1-324 days); 29% developed diarrhea recurrence. Fifty-five percent of norovirus patients were hospitalized for diarrhea, with 27% requiring intensive care unit (ICU) admission. One HSCT recipient developed pneumatosis intestinalis. Three HSCT patients expired ≤6 months of norovirus diarrhea onset. Compared to non-norovirus diarrhea patients, norovirus patients experienced significantly more frequent ICU admission (27% vs. 0%, p = 0.02), greater serum creatinine rise (median 0.3 vs. 0.2 mg/dL, p = 0.01), and more weight loss (median 1.6 vs. 0.6 kg, p < 0.01). Noroviruses are an important cause of diarrhea in pediatric transplant patients and are associated with significant clinical complications.

Reducing Unnecessary and Duplicate Ordering for Ovum and Parasite Examinations and Clostridium difficile PCR in Immunocompromised Patients by Using an Alert at the Time of Request in the Order Management System

We implemented hospital information system (HIS) alerts to deter unnecessary test orders for ovum and parasite (O&P) exams and Clostridium difficile PCR. The HIS alerts decreased noncompliant O&P orders (orders after >72 h of hospitalization) from 49.8% to 30.9%, an overall decrease of 19%, and reduced noncompliant C. difficile PCR orders (orders <7 days after a previous positive result) from 30.6% to 19.2%, an overall decrease of 31.9%.

Rotavirus in organ transplantation: drug-virus-host interactions

Although rotavirus is usually recognized as the most common etiology of diarrhea in young children, it can in fact cause severe diseases in organ transplantation recipients irrespective of pediatric or adult patients. This comprehensive literature analysis revealed 200 cases of rotavirus infection with 8 related deaths in the setting of organ transplantation been recorded. Based on published cohort studies, an average incidence of 3% (187 infections out of 6176 organ recipients) was estimated. Rotavirus infection often causes severe gastroenteritis complications and occasionally contributes to acute cellular rejection in these patients. Immunosuppressive agents, universally used after organ transplantation to prevent organ rejection, conceivably play an important role in such a severe pathogenesis. Interestingly, rotavirus can in turn affect the absorption and metabolism of particular immunosuppressive medications via several distinct mechanisms. Even though rotaviral enteritis is self-limiting in general, infected transplantation patients are usually treated with intensive care, rehydration and replacement of nutrition, as well as applying preventive strategies. This article aims to properly assess the clinical impact of rotavirus infection in the setting of organ transplantation and to disseminate the interactions among the virus, host and immunosuppressive medications.

Bacterial foodborne infections after hematopoietic cell transplantation

Diarrhea, abdominal pain, and fever are common among patients undergoing hematopoietic cell transplantation (HCT), but such symptoms are also typical with foodborne infections. The burden of disease caused by foodborne infections in patients undergoing HCT is unknown. We sought to describe bacterial foodborne infection incidence after transplantation within a single-center population of HCT recipients. All HCT recipients who underwent transplantation from 2001 through 2011 at the Fred Hutchinson Cancer Research Center in Seattle, Washington were followed for 1 year after transplantation. Data were collected retrospectively using center databases, which include information from transplantation, on-site examinations, outside records, and collected laboratory data. Patients were considered to have a bacterial foodborne infection if Campylobacter jejuni/coli, Listeria monocytogenes, E. coli O157:H7, Salmonella species, Shigella species, Vibrio species, or Yersinia species were isolated in culture within 1 year after transplantation. Nonfoodborne infections with these agents and patients with pre-existing bacterial foodborne infection (within 30 days of transplantation) were excluded from analyses. A total of 12 of 4069 (.3%) patients developed a bacterial foodborne infection within 1 year after transplantation. Patients with infections had a median age at transplantation of 50.5 years (interquartile range [IQR], 35 to 57), and the majority were adults ≥18 years of age (9 of 12 [75%]), male gender (8 of 12 [67%]) and had allogeneic transplantation (8 of 12 [67%]). Infectious episodes occurred at an incidence rate of 1.0 per 100,000 patient-days (95% confidence interval, .5 to 1.7) and at a median of 50.5 days after transplantation (IQR, 26 to 58.5). The most frequent pathogen detected was C. jejuni/coli (5 of 12 [42%]) followed by Yersinia (3 of 12 [25%]), although Salmonella (2 of 12 [17%]) and Listeria (2 of 12 [17%]) showed equal frequencies; no cases of Shigella, Vibrio, or E. coli O157:H7 were detected. Most patients were diagnosed via stool (8 of 12 [67%]), fewer through blood (2 of 12 [17%]), 1 via both stool and blood simultaneously, and 1 through urine. Mortality due to bacterial foodborne infection was not observed during follow-up. Our large single-center study indicates that common bacterial foodborne infections were a rare complication after HCT, and the few cases that did occur resolved without complications. These data provide important baseline incidence for future studies evaluating dietary interventions for HCT patients.

Diarrhea in enterally fed patients: blame the diet?

PURPOSE OF REVIEW

Diarrhea has great impact on enteral nutrition. The purpose of this review is to identify the factors leading to diarrhea during enteral nutrition and to provide the published updates on diarrhea prevention through nutritional intervention.

RECENT FINDINGS

Diarrhea in enteral fed patients is attributed to multiple factors, including medications (major contributor), infections, bacterial contamination, underlying disease, and enteral feeding. Diet management can alleviate diarrhea in enteral feeding. High content of fermentable oligosaccharides, disaccharides, and monosaccharides and polyols (FODMAPs) in enteral formula is postulated to induce diarrhea and lower FODMAPs formula may reduce the likelihood of diarrhea in enterally fed patients. Fiber-enriched formula can reduce the incidence of diarrhea and produce short-chain fatty acids for colonocytes. Ingesting prebiotics, nonviable probiotics or probiotic derivatives, and human lactoferrin may provide alternatives for reducing/preventing diarrhea.

SUMMARY

Enteral feeding is not generally considered the primary cause of diarrhea, which is frequently linked to prescribed medications. When diarrhea is apparent, healthcare members should evaluate the possible risk factors and systematically attempt to eliminate the underlying causes of diarrhea before reducing or suspending enteral feeding. Lower FODMAPs formula, prebiotics, probiotic derivatives, and lactoferrin may be used to manage enteral feeding-related diarrhea.

Diagnosis and management of gastrointestinal complications in adult cancer patients: evidence-based guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

BACKGROUND

Cancer patients frequently suffer from gastrointestinal complications. However, a comprehensive, practical and evidence-based guideline on this issue is not yet available.

PATIENTS AND METHODS

An expert group was put together by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO) to develop a guideline on gastrointestinal complications in cancer patients. For each subtopic, a literature search was carried out in PubMed, Medline and Cochrane databases and the strength of recommendation and the quality of the published evidence for major therapeutic strategies were categorized using a modification of the 'Infectious Diseases Society of America' criteria. Consensus discussions were held on each of the topics.

RESULTS

Recommendations were made with respect to non-infectious and infectious gastrointestinal complications. For all recommendations, the strength of the recommendation and the level of evidence are presented.

CONCLUSION

This guideline is an evidence-based approach to the diagnosis and management of gastrointestinal complications in cancer patients.

Diarrhea in the immunocompromised patient

Diarrhea is a common problem in patients with immunocompromising conditions. The etiologic spectrum differs from patients with diarrhea who have a normal immune system. This article reviews the most important causes of diarrhea in immunocompromised patients, ranging from infectious causes to noninfectious causes of diarrhea in the setting of HIV infection as a model for other conditions of immunosuppression. It also deals with diarrhea in specific situations, eg, after hematopoietic stem cell or solid organ transplantation, diarrhea induced by immunosuppressive drugs, and diarrhea in congenital immunodeficiency syndromes.

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.

Infections in Leukemia and Hematopoietic Stem Cell Transplantation

Infections are one of the most common complications in patients diagnosed with leukemia and serve as a major obstacle to treatment. Through the early 1970s, infections were the most common cause of death in patients diagnosed with acute leukemia, but improvement in treatment and supportive care over the past few decades, coupled with expanded prophylaxis and prevention regimens, have led to reduction in both the frequency and severity of infections. Regardless, due in part to an aging cancer population and the diversity of cancer treatments and procedures, infectious diseases remain a major cause of morbidity and mortality in patients with leukemia.