Infectious Causes of Acute Gastroenteritis in US Children Undergoing Allogeneic Hematopoietic Cell Transplant: A Longitudinal, Multicenter Study

Acute diarrhea in the hospitalized immunocompromised patient: what is new on diagnostic and treatment?

PURPOSE OF REVIEW

This article aims to provide an intuitive framework for diagnosing and managing healthcare-associated diarrhea (HCAD) in the immunocompromised (IC) host.

RECENT FINDINGS

Our understanding of diarrhea in hospitalized IC patients has significantly evolved. However, the challenge lies in distinguishing between these patients' numerous causes of diarrhea. The incorporation of gastrointestinal (GI) multiplex polymerase chain reaction (PCR) panels has led to a paradigm shift in our approach to diarrhea. However, using these panels judiciously is of utmost importance, as their misuse can lead to over-testing, overtreatment, and increased hospital costs. We propose a stepwise diagnostic algorithm that ensures diagnostic stewardship, optimal patient care, and resource utilization.

SUMMARY

Diarrhea is a common complication in hospitalized IC patients and is associated with significant morbidity and rare mortality. The advent of new diagnostics, such as GI multiplex PCR panels, holds promise in facilitating the detection of recognized pathogens and may allow for improved outcomes using pathogen-targeted therapy.

Protective role of antibodies in enteric virus infections: Lessons from primary and secondary immune deficiencies

Enteric viruses are the main cause of acute gastroenteritis worldwide with a significant morbidity and mortality, especially among children and aged adults. Some enteric viruses also cause disseminated infections and severe neurological manifestations such as poliomyelitis. Protective immunity against these viruses is not well understood in humans, with most knowledge coming from animal models, although the development of poliovirus and rotavirus vaccines has extended our knowledge. In a classical view, innate immunity involves the recognition of foreign DNA or RNA by pathogen recognition receptors leading to the production of interferons and other inflammatory cytokines. Antigen uptake and presentation to T cells and B cells then activate adaptive immunity and, in the case of the mucosal immunity, induce the secretion of dimeric IgA, the more potent immunoglobulins in viral neutralization. The study of Inborn errors of immunity (IEIs) offers a natural opportunity to study nonredundant immunity toward pathogens. In the case of enteric viruses, patients with a defective production of antibodies are at risk of developing neurological complications. Moreover, a recent description of patients with low or absent antibody production with protracted enteric viral infections associated with hepatitis reinforces the prominent role of B cells and immunoglobulins in the control of enteric virus.

Determination of Risk Factors for Infectious Diarrhea in Patients with Hematological Malignancy

BACKGROUND

This study aimed to determine the risk factors of infectious diarrhea in patients undergoing chemotherapy or hematopoietic stem cell transplantation for hematological malignancies.

MATERIALS AND METHODS

This was a prospective, observational study. Patients in whom the infectious agent was determined by laboratory examination were considered to have infectious diarrhea. Patients with diarrhea were categorized as infectious or unidentified and compared in terms of demographic data, treatments, risk factors, laboratory findings, and prognosis.

RESULTS

A total of 838 patients were hospitalized, among which 105 patients who met the inclusion criteria were included (12.5%). The patients were divided into two groups: 67 (63.8%) with unidentified diarrhea and 38 (36.2%) with infectious diarrhea. There were no differences between these groups in terms of age, sex, types of hematological malignancies, and presence of comorbidities. The most commonly isolated microorganism was Clostridioides difficile (12.4%). The rate of corticosteroid use was higher in the group with infectious diarrhea (39.5%) than in the group with unidentified diarrhea (7.5%) (P <0.001). The rate of granulocyte colony-stimulating factor (GCSF) use was higher in patients with unidentified diarrhea than in patients with infectious diarrhea (67.2% vs. 42.1%, P=0.022). The median duration of diarrhea was 9 (4-10) days in the group with infectious diarrhea and 5 (3-8) days in the group with unidentified diarrhea (P=0.012). According to the multivariate logistic regression model, corticosteroid treatment increased the risk of infectious diarrhea by a 4.75-fold (95% confidence interval [CI], 1.32-17.02) times. Moreover, the duration of diarrhea may result in a 1.15 (95% CI, 1.02-1.31) fold increase in the risk of infectious diarrhea, while GCSF treatment had a 2.84 (1/0.35) (95% CI, 0.12-0.96) fold risk-reducing effect against infectious diarrhea.

CONCLUSION

Infectious diarrhea lasts longer than unidentified diarrhea in patients with hematological malignancies. Although corticosteroid use is a risk factor for developing infectious diarrhea, GCSF use has a protective effect.

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.

Enterovirus Infections in Solid Organ Transplant Recipients: a Clinical Comparison from a Regional University Hospital in the Netherlands

Enterovirus infections are known to cause a diverse range of illnesses, even in healthy individuals. However, information detailing enterovirus infections and their severity in immunocompromised patients, such as transplant recipients, is limited. We compared enterovirus infections in terms of genotypes, clinical presentation, and severity between transplant and nontransplant patients. A total of 264 patients (38 transplant recipients) with 283 enterovirus infection episodes were identified in our hospital between 2014 and 2018. We explored the following factors associated with enterovirus infections: clinical presentation and diagnosis on discharge, length of hospital stay, symptom persistence, and infection episodes in both children and adults. We observed some differences in genotypes between patients, with enterovirus group C occurring mainly in transplant recipients (P < 0.05). EV-associated gastrointestinal infections were more common in patients with a transplant (children [71%] and adults [46%]), compared to nontransplant patients (P < 0.05). Additionally, nontransplant patients had a higher number of hospital stays (P < 0.05), potentially reflecting more severe disease. However, transplant patients were more likely to have symptom persistence after discharge (P < 0.05). Finally, children and adults with a transplant were more likely to have additional enterovirus infection episodes (P < 0.05). In our cohort, enterovirus infections did not seem to be more severe after transplantation; however, patients tended to present with different clinical symptoms and had genotypes rarely found in nontransplant recipients.

IMPORTANCE Despite the high prevalence of enteroviruses in the community and the increasing demand for transplants from an aging population, knowledge on enteroviruses in solid organ transplant recipients is currently limited. Transplant recipients represent a significant patient population and require additional considerations in patient management, particularly as they have an increased risk of disease severity. Enteroviruses are known to cause significant morbidity, with a diverse range of clinical presentation from over 100 different genotypes. In this study, we aimed to provide a more comprehensive overview of enteroviral infections in transplant recipients, compared to nontransplant patients, and to bridge some gaps in our current knowledge. Identifying potential clinical manifestation patterns can help improve patient management following enterovirus infections.

Global molecular prevalence and genotype distribution of Sapovirus in children with gastrointestinal complications: A systematic review and meta-analysis

Sapovirus (SaV) is an emerging cause of children gastrointestinal complications such as acute gastroenteritis (AGE). The aim of the present systematic review and meta-analysis was to estimate the global prevalence of the SaV in children and association of infection with SaVs and AGE in children based on case-control studies. Four international databases (PubMed, Scopus, Web of Sciences and Google Scholar) were used to retrieve English-language studies published between January 2000 and December 2020. Comprehensive Meta-Analysis software was applied to estimate the overall prevalence, publication bias and heterogeneity index. The pooled prevalence of SaV infection among children with gastroenteritis was 3.4% [95% confidence interval (CI): 2.9%-3.9%] based on a random-effects meta-analysis. Genogroup I was the dominant genogroup of SaV in children with gastroenteritis [2.2% (95% CI: 1.6%-3.0%)], association analysis showed that SaV was associated with gastroenteritis [OR: 1.843 (95% CI: 1.27-2.66)]. Given the significant prevalence of the virus in children, it is necessary to pay more attention to this situation. Therefore, preventive health measures in children should be a priority.

Sapovirus detection and quantification in fecal samples from allogeneic hematopoietic stem cell transplant recipients

Sapovirus are important agents of acute gastroenteritis (AGE) and they are associated with outbreaks and sporadic cases worldwide. They infect people of all ages, but mainly children, the elderly and immunocompromised individuals are affected. The aim of this study was investigate sapovirus and to determine viral loads in fecal samples from patient undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Fecal samples were submitted to extraction of the genetic material using a commercial kit, and RT-qPCR TaqMan was used for sapovirus screening and determination of viral loads, using a standard curve with serial dilutions of a recombinant plasmid. Positive samples were sequence by Sanger method. Sapovirus was detected in one patient, 5.3% (1/19). Viral excretion lasted for 16 days. Viral load varied from 1.73 × 10⁶ to 8.97 × 10⁶ GC/g. One of the positive samples was characterized as GI.1 genotype. This is the first study to determine sapovirus loads in samples from allo-HSCT and to identify GI.1 genotype in immunocompromised patients.