Diagnosis of Clostridium difficile Infections in Children

Use of PCR Cycle Threshold and Clinical Interventions to Aid in the Management of Pediatric Clostridioides difficile Patients

Better diagnostic tools are needed to improve the diagnosis of Clostridioides difficile infections (CDI) and reduce the overtreatment of colonized children. In this study, we evaluated two polymerase chain reaction (PCR) assays (Cepheid GeneXpert C. difficile and the Gastroenteritis PCR Panel by QIAstat-Dx) as a standalone method in combination with the PCR cycle threshold (Ct) value in positive samples to predict the presence of free toxins. We also evaluated the clinical impact of reporting toxin production results and provided comments alongside the PCR results in our pediatric population. PCR-positive stool samples from pediatric patients (aged 2 to 18 years old) were included in our study and tested for the presence of toxins A and B using the C. difficile Quik Chek Complete kit. For the clinical intervention, the CDI treatment rates 6 months pre- and post-intervention were compared. The use of PCR Ct value showed excellent sensitivity (100%) at a Ct value cutoff of 26.1 and 27.2 using the Cepheid GeneXpert C. difficile and the Gastroenteritis PCR Panel by QIAstat-Dx, respectively, while the toxin test showed inferior sensitivity of 64% in the PCR-positive samples. In addition, CDI treatment rates were decreased by 23% post-intervention. The results of our study suggest that nucleic acid amplification test (NAAT) assays supplemented by the use of PCR Ct value for positive samples can be used as standalone tests to differentiate CDI from colonization. Furthermore, the reporting of toxin production along with the PCR results can help reduce the unnecessary treatment of colonized children.

Analysis of risk factors for community-acquired Clostridioides difficile diarrhea in children: a case-control study in Chenzhou, China

Background

Most previous studies on Clostridium difficile infection (CDI) mainly focused on adults with underlying diseases or critical illnesses. However, the number of CDI cases in children has also significantly increased, especially the growth of community-acquired CDI, which has attracted attention. This study was conducted to examine the toxin gene characteristics and the risk factors associated with community-acquired CDI (CA-CDI) in children with diarrhea.

Methods

Children with diarrhea before admission or within 48 hours of hospitalization were included in the study. Stool samples were collected from children with community-acquired diarrhea who were treated at the Children's Hospital of the First People's Hospital of Chenzhou, China from June of 2021 to June of 2022. Fluorescence real-time polymerase chain reaction was utilized to detect Clostridioides difficile (CD) toxins A (tcdA) and B (tcdB) genes as well as binary toxin gene A (cdtA) and B (cdtB) in the specimens cultured for CD. Each child with CA-CDI was matched with four control children of the same sex, age, and place of residence. Necessary clinical data were extracted from the hospital's electronic medical record system. Then, a multivariate conditional logistic regression analysis was applied to identify potential risk factors for CA-CDI.

Results

Sixteen (8.3%) of the 193 stool specimens who tested positive for CD were selected for the case group, and their matching 64 control patients were in the study cohort. The breakdown of the CD genotypes of the 16 positive cases were follows: 14 (tcdA+ and tcdB+) (7.25%) and 2 (tcdA+ and tcdB-) (1.04%). The cdtA and cdtB binary toxin genes were negative in all. The results of multivariate conditional logistic regression analysis identified antibiotic use within the previous month [odds ratio (OR) =5.13; 95% confidence interval (CI): 1.65-15.91] and non-breastfeeding (OR =4.89; 95% CI: 1.11-21.53) as independent risk factors for CDI in pediatric patients experiencing community-acquired diarrhea.

Conclusions

Children who had been treated with antibiotics and not breastfed were more susceptible to CDI. Therefore, in order to prevent and to control the spread of CD infection, being prudent to the aforementioned high-risk factors is strongly advocated in clinical practice.

Clostridioides difficile infection in infants: a case report and literature review

BACKGROUND

Clostridioides difficile (C. difficile) is the major pathogen causing antibiotic-associated diarrhea. There are a variety of symptoms associated with C. difficile infection (CDI) in adults, including self-limiting diarrhea, pseudomembranous colitis, toxic megacolon, septic shock, and even death from the infection. However, the infant's intestine appears to be completely resistant to the effects of C. difficile toxins A and B with rare development of clinical symptoms.

CASE PRESENTATION

In this study, we reported a 1-month-old girl with CDI who was born with neonatal hypoglycemia and necrotizing enterocolitis. Her symptom of diarrhea occurred after extensive use of broad-spectrum antibiotics during hospitalization and was accompanied by elevated white blood cell, platelet, and C-reactive protein levels, and repeated routine stool examinations were abnormal. She was recovered by norvancomycin (an analogue of vancomycin) and probiotic treatment. The results of 16 S rRNA gene sequencing also demonstrated the recovery of intestinal microbiota with the enrichment of Firmicutes and Lactobacillus.

CONCLUSIONS

Based on the literature review and this case report, clinicians should also pay attention to diarrhea caused by C. difficile in infants and young children. More strong evidence is needed to explain the true prevalence of CDI in this population and to better understand the C. difficile-associated diarrhea in infants.

Successful diagnostic stewardship for Clostridioides difficile testing in pediatrics

OBJECTIVE

To reduce both inappropriate testing for and diagnosis of healthcare-onset (HO) Clostridioides difficile infections (CDIs).

DESIGN

We performed a retrospective analysis of C. difficile testing from hospitalized children before (October 2017-October 2018) and after (November 2018-October 2020) implementing restrictive computerized provider order entry (CPOE).

SETTING

Study sites included hospital A (a ∼250-bed freestanding children's hospital) and hospital B (a ∼100-bed children's hospital within a larger hospital) that are part of the same multicampus institution.

METHODS

In October 2018, we implemented CPOE. No testing was allowed for infants aged ≤12 months, approval of the infectious disease team was required to test children aged 13-23 months, and pathology residents' approval was required to test all patients aged ≥24 months with recent laxative, stool softener, or enema use. Interrupted time series analysis and Mann-Whitney U test were used for analysis.

RESULTS

An interrupted time series analysis revealed that from October 2017 to October 2020, the numbers of tests ordered and samples sent significantly decreased in all age groups (P < .05). The monthly median number of HO-CDI cases significantly decreased after implementation of the restrictive CPOE in children aged 13-23 months (P < .001) and all ages combined (P = .003).

CONCLUSION

Restrictive CPOE for CDI in pediatrics was successfully implemented and sustained. Diagnostic stewardship for CDI is likely cost-saving and could decrease misdiagnosis, unnecessary antibiotic therapy, and overestimation of HO-CDI rates.

Infectious Etiology of Vomiting in Children With Presumed Acute Gastroenteritis in the Absence of Diarrhea: Protocol for a Cohort Study

NCT05270291, https://clinicaltrials.gov/ct2/show/.

Objectives

In children with acute gastroenteritis (AGE), vomiting often precedes diarrhea. To establish the diagnosis of AGE, enteropathogen detection typically relies on diarrheal stool samples. However, testing requires sufficient stool sample, which may not be easily available. Recent studies suggest that in children presenting to emergency departments with presumed AGE with isolated vomiting, an enteropathogen can be identified using rectal swabs and molecular diagnostic tests. The rate of enteropathogen detection in children with isolated vomiting due to AGE may differ in various populations. Using rectal swabs and molecular diagnostic tests, we plan to assess the proportion of children with isolated vomiting with presumed AGE in whom an enteropathogen can be identified.

Methods

This will be a cohort study conducted in the emergency department(s) of one or more pediatric hospital(s) in Poland. Children younger than 5 years with the presence of ≥3 episodes of vomiting due to presumed AGE, lasting no longer than 7 days before enrollment, will be recruited. The primary outcome will be the proportion of children with isolated vomiting in whom an enteropathogen is detected. In all eligible participants, rectal swabs will be taken to perform molecular testing for detection of typical viral and bacterial enteropathogens. All children will be followed-up at 14 days after the initial contact to classify them into one of three groups (i.e., vomiting only, vomiting and diarrhea, and diarrhea only).

Clostridioides (Clostridium) difficile in children with diarrhoea in Vietnam

BACKGROUND

Clostridioides (Clostridium) difficile commonly causes hospital-acquired infection which can range from mild diarrhoea to life-threatening toxic megacolon and even death. Reports on C. difficile infection (CDI) in Vietnam are limited, so this study was designed to evaluate the prevalence, molecular epidemiology and antimicrobial susceptibility of C. difficile isolated from children with diarrhoea in Vietnam. Infants are often colonised with C. difficile and it was hypothesised that those colonising strains would represent strains of C. difficile circulating in the hospital/region at the time, however, this was not an attempt to determine if C. difficile was the cause of the diarrhoea.

METHODS

Diarrhoeal stool samples collected at two children's hospitals in northern Vietnam from 1^st October 2020 to 28^th February 2021 were transported to Perth, Western Australia, for culture of C. difficile and further investigations on isolates; PCR ribotyping, toxin gene profiling and antimicrobial susceptibility testing.

RESULTS

From these hospitals, 370 diarrhoeal stool samples were collected, most from children aged 1-15 months (71.9%; 266/370). The overall prevalence of C. difficile in stool samples from children aged ≤16 years was 37.8% (140/370) and the highest prevalence was in the 2-12 months age group (52.9%; 74/140). In total, 151 isolates of C. difficile were recovered; the proportion of toxigenic isolates was 16.6% (25/151). Of the 25 toxigenic C. difficile isolates, the toxin gene profiles A⁺B⁺CDT^- and A^-B⁺CDT^- comprised 72% and 28%, respectively. The four most prevalent C. difficile ribotypes (RTs) were QX 011 (25/151), RT 010 (25/151), QX 107 (12/151) and RT 012 (11/151). All isolates were susceptible to vancomycin, metronidazole and fidaxomicin, while there was significant resistance to clindamycin (90.1%), and some to moxifloxacin (6.6%) and rifaximin (3.3%).

CONCLUSION

The prevalence of C. difficile in children with diarrhoea was high (37.8%) although the proportion of toxigenic strains was comparatively low. The clinical significance of any isolate needs to be determined.

Pharmacological Management of Pediatric Clostridioides difficile Infection: Clarifying the Controversies

Clostridioides difficile infection (CDI) is a major public health concern for pediatric and adult patients. The management of pediatric CDI poses a challenge to healthcare providers due to lack of strong randomized controlled trials to guide pharmacological management. Additionally, recent updates to CDI guidelines recommend oral vancomycin over metronidazole for the management of CDI in adults, leaving questions regarding how to best manage pediatric patients. This continuing education pharmacotherapy review describes available evidence for the safety and efficacy of medications used in the treatment and management of pediatric CDI and aims to clarify discrepancies between pediatric and adult recommendations.

Clostridioides (Clostridium) difficile isolated from paediatric patients in Western Australia 2019-2020

Less is understood about the epidemiology of Clostridioides difficile infection (CDI) in children compared to adults, and its impact is complicated by variations in the natural development of infection in paediatric patients. The interplay of rising CDI incidence in hospitalised paediatric patients, emergence of hypervirulent strains and community associated CDI (CA-CDI) in the past decade is a potential threat in both hospital and community settings. Research in Australia regarding paediatric CDI is limited. Here, we report the molecular characterisation of C. difficile isolated from paediatric patients at a tertiary hospital in Perth, Western Australia. A total of 427 stool samples was collected from patients aged from <1 to 17 years being investigated for diarrhoea from July 2019 to June 2020. Stool specimens were cultured and isolates of C. difficile characterised by ribotyping and toxin gene profiling. Clostridioides difficile was recovered from 84/427 (19.7%) samples tested. The most prevalent PCR ribotypes (RTs) were RT 002 (12.4%), a toxigenic strain, and RT 009 (15.7%), a non-toxigenic strain. Interestingly, C. difficile RT 078 and RT 017, strains that are not endemic in Australia, were isolated from a 1- and 4-year-old child, respectively. Clostridioides difficile RT 106, a strain of emerging importance in Australia, was recovered from two cases (5.3%). Resistance to metronidazole, fidaxomicin, amoxicillin, rifaximin and meropenem was not detected, however, 45 isolates (50.6%) showed resistance to at least one agent, and multidrug resistance was observed in 13.3% of the resistant isolates (6/45). This study provides a baseline for future surveillance of paediatric CDI in Australia. Given that young children can be asymptomatically colonised with toxigenic C. difficile strains, they represent a potential reservoir of strains causing CDI in adults.

Gut Dysbiosis and Clostridioides difficile Infection in Neonates and Adults

In this review, we focus on gut microbiota profiles in infants and adults colonized (CDC) or infected (CDI) with Clostridioides difficile. After a short update on CDI epidemiology and pathology, we present the gut dysbiosis profiles associated with CDI in adults and infants, as well as the role of dysbiosis in C. difficile spores germination and multiplication. Both molecular and culturomic studies agree on a significant decrease of gut microbiota diversity and resilience in CDI, depletion of Firmicutes, Bacteroidetes, and Actinobacteria phyla and a high abundance of Proteobacteria, associated with low butyrogenic and high lactic acid-bacteria levels. In symptomatic cases, microbiota deviations are associated with high levels of inflammatory markers, such as calprotectin. In infants, colonization with Bifidobacteria that trigger a local anti-inflammatory response and abundance of Ruminococcus, together with lack of receptors for clostridial toxins and immunological factors (e.g., C. difficile toxins neutralizing antibodies) might explain the lack of clinical symptoms. Gut dysbiosis amelioration through administration of “biotics” or non-toxigenic C. difficile preparations and fecal microbiota transplantation proved to be very useful for the management of CDI.

Pediatric Clostridioides difficile Infection: Diagnosis and Diagnostic Stewardship

Although the pathogenesis of Clostridioides difficile infection (CDI) is complex and incompletely understood, it is believed that the elaboration of C. difficile toxins is necessary for disease. There are a variety of tests available for the detection of both the C. difficile organism and its toxins; however, each has limitations and the best application of these tests to the diagnosis of CDI in children remains uncertain. Nucleic acid amplification tests are unable to reliably discriminate between CDI and C. difficile colonization, while commercially available enzyme immunoassays for toxin detection lack sensitivity. An understanding of preanalytic factors, relevant patient features, and test performance characteristics is essential to the accurate diagnosis of CDI in children. Specific diagnostic stewardship strategies can also increase the likelihood that positive tests reflect disease rather than colonization. Ultimately, CDI remains a clinical diagnosis and clinical judgment is essential when interpreting test results, regardless of the methods used.

An evaluation of toxigenic Clostridioides difficile positivity as a patient outcome metric of antimicrobial stewardship in Saudi Arabia

Background

Antimicrobial stewardship has been associated with a reduction in the incidence of healthcare-associated Clostridium difficile infection (HA-CDI). However, CDI remains under-recognised in many low and middle-income countries where clinical and surveillance resources required to identify HA-CDI are often lacking. The rate of toxigenic C. difficile stool positivity in the stool of hospitalised patients may offer an alternative metric for these settings, but its utility remains largely untested.

Aim/objective

To examine the impact of antimicrobial stewardship on the rate of toxigenic C. difficile positivity among hospitalised patients presenting with diarrhea.

Methods

A 12-year retrospective review of laboratory data was conducted to compare the rates of toxigenic C. difficile in diarrhoea stool of patients in a hospital in Saudi Arabia, before and after implementation of an antimicrobial stewardship programme.

Result

There was a significant decline in the rate of toxigenic C. difficile positivity from 9.8 to 7.4% following the implementation of the antimicrobial stewardship programme, and a reversal of a rising trend.

Discussion

The rate of toxigenic C. difficile positivity may be a useful patient outcome metric for evaluating the long-term impact of antimicrobial stewardship on CDI, especially in settings with limited surveillance resources. The accuracy of this metric is, however, dependent on the avoidance of arbitrary repeated testing of a patient for cure, and testing only unformed or diarrhoea stool specimens. Further studies are required within and beyond Saudi Arabia to examine the utility of this metric.

Recent advances in Clostridioides difficile infection epidemiology, diagnosis and treatment in children

PURPOSE OF REVIEW

The US Centers for Disease Control and Prevention (CDC) classified Clostridioides difficile as an 'urgent' public health threat that requires 'urgent and aggressive action'. This call to action has led to new discoveries that have advanced C. difficile infection (CDI) epidemiology, diagnosis and treatment, albeit predominantly in adults. In 2017, the Infectious Diseases Society of America and Society for Healthcare Epidemiology of America published clinical practice guidelines for both adults and children. At that time, recommendations in children were generally limited to relatively low-quality evidence.

RECENT FINDINGS

Since publication of this guidance, there have been many advancements in the understanding of CDI in children. These include better understanding of healthcare settings as uncommon sources of C. difficile acquisition in children; risk factors for recurrent and community-associated CDI; performance of diagnostic tests in children and strategies for optimizing their use; and a more rigorous evidence base for CDI treatment in children, including the first-ever randomized controlled trial of CDI treatment in children and the largest study of fecal microbiota transplantation in children.

SUMMARY

This review highlights the most recent salient advancements in paediatric CDI knowledge and practice that supplement published clinical guidance provided prior to these advancements.

Epidemiologic and Clinical Characteristics of Clostridioides difficile Infections in Hospitalized and Outpatient Pediatric Oncology and Hematopoietic Stem Cell Transplant Patients

BACKGROUND

The epidemiology and clinical course of Clostridioides difficile infection (CDI) in children, especially with cancer, are poorly defined. We aim to describe the epidemiology, clinical features and outcomes of CDI and to identify risk factors for recurrence in a pediatric oncology center.

METHODS

This is a retrospective cohort study of CDI in pediatric oncology and hematopoietic stem cell transplant (HSCT) patients in 2016 and 2017. CDI cases were identified by positive C. difficile test in symptomatic patients. CDI episodes were classified as incident, duplicate or recurrent and community-onset, hospital-onset or community-onset healthcare facility-associated. Data about clinical course and outcomes were abstracted. Risk factors for CDI recurrence were assessed by logistic regression.

RESULTS

One hundred seventy-eight patients 1 year of age and older developed 291 CDI episodes; 78% were incident and 22% recurrent. Underlying diagnoses were leukemia/lymphoma (57%) and solid/brain tumors (41%); 30% were HSCT recipients. Antibiotics, chemotherapy, antacids, steroids and laxatives were received by 96%, 82%, 70%, 47% and 15%, respectively. Half of the patients were neutropenic. Twenty-two percent of outpatients with CDI required hospitalization. Chemotherapy was delayed in 25%. There were no intensive care unit admissions nor deaths due to CDI. Exposure to H2-antagonists was identified as an independent risk factor for CDI recurrence.

CONCLUSIONS

Although CDI in pediatric oncology and HSCT patients was associated with chemotherapy delay and hospitalization in approximately a quarter of patients, it was not associated with morbidity or mortality because patients had no attributable intensive care unit admission nor death. H2-antagonists are independent risk factors for CDI recurrence.

Microbial Etiologies and Clinical Characteristics of Children Seeking Emergency Department Care Due to Vomiting in the Absence of Diarrhea

BACKGROUND

As children with isolated vomiting are rarely able to provide a specimen suitable for routine pathogen testing, we have limited knowledge about their infecting pathogens.

METHODS

Between December 2014 and August 2018, children <18 years old with presumed acute gastroenteritis who presented to 2 emergency departments (EDs) in Alberta, Canada, were recruited. Eligible participants had ≥3 episodes of vomiting and/or diarrhea in a 24-hour period, <7 days of symptoms, and provided a rectal swab or stool specimen. We quantified the proportion of children with isolated vomiting in whom an enteropathogen was identified, and analyzed clinical characteristics, types of enteropathogens, resources used, and alternative diagnoses.

RESULTS

Of the 2695 participants, at the ED visit, 295 (10.9%), 1321 (49.0%), and 1079 (40.0%) reported having isolated diarrhea, vomiting and diarrhea, or isolated vomiting, respectively. An enteropathogen was detected most commonly in those with vomiting and diarrhea (1067/1321; 80.8%); detection did not differ between those with isolated diarrhea (170/295; 57.6%) and isolated vomiting (589/1079; 54.6%) (95% confidence interval of the difference: -3.4%, 9.3%). Children with isolated vomiting most often had a virus (557/1077; 51.7%), most commonly norovirus (321/1077; 29.8%); 5.7% (62/1079) had a bacterial pathogen. X-rays, ultrasounds, and urine tests were most commonly performed in children with isolated vomiting. Alternate etiologies were most common in those with isolated vomiting (5.7%; 61/1079).

CONCLUSIONS

The rate of enteropathogen identification in children with isolated vomiting using molecular diagnostic tests and rectal swabs is substantial. Molecular diagnostics offer an emerging diagnostic strategy in children with isolated vomiting.

Prevention of Clostridioides difficile in hospitals: A position paper of the International Society for Infectious Diseases

Clostridioides difficile infection is an increasing presence worldwide. Prevention is multipronged, reflecting a complex and evolving epidemiology. Multiple guidelines exist regarding the prevention of C. difficile infection in healthcare settings; however, existing guidelines do not address C. difficile in low- and middle-income countries (LMIC). Nevertheless, the prevalence of C. difficile in LMIC likely parallels, if not exceeds, that of high-income countries, and LMIC may experience additional challenges in C. difficile diagnosis and control. A panel of experts was convened by the International Society for Infectious Diseases (ISID) to review the current state of C. difficile infections globally and make evidence-based recommendations for infection prevention that are broadly applicable.

Recurrent community-acquired Clostridium(Clostridioides)difficile infection in Serbianchildren

Information on recurrent Clostridium difficile infections (rCDI) in children is rare and limited, especially community acquired (CA-CDI).This study was designed to identify risk factors for rCA-CDI in Serbian pediatric population. The study group included 71 children (aged from 1 to 14 years) with a first episode of CDI. Data were collected from 56 (78.87%) children with only one episode of CA-CDI and from 15 (21.13%) children with rCA-CDI were mutually compared. The following parameters were found to be statistically significantly more frequent in the children with rCA-CDI group (p < 0.05); leukemia as underlying disease, treatment with immunosuppressive and-or cytostatic drugs, and treatment with antibiotics. Similarly, previously visits to outpatient facilities, daycare hospitals and hospitals were also associated with rCDI. Analysis of clinical symptoms and laboratory parameters, revealed a statistically significant association of the severity of the first episode of CDI (determined by an increase in body temperature, higher maximum WBC and higher CRP) with development of a rCDI. Ribotype (RT) 027 was more common in children with rCA-CDI (66.7%, p = 0.006). During the seven-year research period, we found a rate of rCA-CDI rate in children of 21.13%. Our study identified several parameters statistically significantly more frequently in children with rCA-CDI. The obtained results will serve as a basis for future larger studies, but new prospective, studies are necessary to build a prediction model of rCDI in children that can be used to guide the treatment to prevent rCDI.

Overreporting healthcare-associated C. difficile: A comparison of NHSN LabID with clinical surveillance definitions in the era of molecular testing

BACKGROUND

Clostridium difficile infection (CDI) is the most common healthcare-associated gastrointestinal infection. Hospitals are required to report cases of healthcare facility-onset CDI (HO-CDI) using the National Healthcare Safety Network's CDI laboratory-identified (LabID) event definition. The aim of this study was to determine the extent of potential over-reporting due to the exclusion of important clinical data within LabID reporting definitions.

METHODS

In 2015, retrospective chart review was performed on 212 HO-CDI cases reported from a large urban medical center. Cases had positive polymerase chain reaction test for the C. difficile toxin B gene from an unformed stool specimen collected >3 days after admission and >8 weeks after most recent LabID event. Cases were categorized into "clinical surveillance" groups: community-acquired infection, recurrence/relapse, asymptomatic colonization, colonization with self-limited symptoms, possible HO-CDI, and probable HO-CDI.

RESULTS

Of the infections, 13.6% were community acquired, 2.8% were recurrent/relapse, 1.9% were asymptomatic colonization, 18.4% were symptomatic colonization, 38.7% were possible HO-CDI, and 24.5% were probable HO-CDI. Within 24 hours of testing, 34.1% of patients had received a stool softener and/or laxative.

CONCLUSIONS

Laxative use and failure to identify community-onset infection may contribute to misclassification of HO-CDI. Only 62% of reported cases met clinical surveillance criteria.

Expanding Existing Antimicrobial Stewardship Programs in Pediatrics: What Comes Next

The prevalence of pediatric antimicrobial stewardship programs (ASPs) is increasing in acute care facilities across the United States. Over the past several years, the evidence base used to inform effective stewardship practices has expanded, and regulatory interest in stewardship programs has increased. Here, we review approaches for established, hospital-based pediatric ASPs to adapt and report standardized metrics, broaden their reach to specialized populations, expand to undertake novel stewardship initiatives, and implement rapid diagnostics to continue their evolution in improving antimicrobial use and patient outcomes.

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.

A retrospective study of community-acquired Clostridium difficile infection in southwest China

To identify the prevalence and characteristics of community-acquired Clostridium difficile infection (CA-CDI) in southwest China, we conducted a cross-sectional study. 978 diarrhea patients were enrolled and stool specimens’ DNA was screened for virulence genes. Bacterial culture was performed and isolates were characterized by PCR ribotyping and multilocus sequence typing. Toxin genes tcdA and/or tcdB were found in 138/978 (14.11%) cases for fecal samples. A total of 55 C. difficile strains were isolated (5.62%). The positive rate of toxin genes and isolation results had no statistical significance between children and adults groups. However, some clinical features, such as fecal property, diarrhea times before hospital treatment shown difference between two groups. The watery stool was more likely found in children, while the blood stool for adults; most of children cases diarrhea ≤3 times before hospital treatment, and adults diarrhea >3 times. Independent risk factor associated with CA-CDI was patients with fever. ST35/RT046 (18.18%), ST54/RT012 (14.55%), ST3/RT001 (14.55%) and ST3/RT009 (12.73%) were the most distributed genotype profiles. ST35/RT046, ST3/RT001 and ST3/RT009 were the commonly found in children patients but ST54/RT012 for adults. The prevalence of CA-CDI in Yunnan province was relatively high, and isolates displayed heterogeneity between children and adults groups.

Poor yield of Clostridium difficile testing algorithms using glutamate dehydrogenase antigen and C. difficile toxin enzyme immunoassays in a pediatric population with declining prevalence of clostridium difficile strain BI/NAP1/027

We compared the performance of algorithmic Clostridium difficile infection (CDI) diagnosis with four molecular tests in children. Stool samples in patients 1-18 years old were tested with an algorithm (C. Diff Quik Chek Complete (QCC) reflexed to illumigene C. difficile); AmpliVue C. difficile (ACD); Lyra Direct C. difficile (Lyra); BD MAX C diff (BDM); and Xpert C. difficile (XCD). The gold standard was positivity by two tests. Sensitivity, specificity, positive predictive value, and negative predictive value were 85%, 99%, 93%, 97% for the algorithm; 21%, 99%, 78%, 87% for QCC's toxin component; 94%, 99%, 94%, 99% for ACD; 88%, 99%, 94%, 98% for Lyra; 94%, 100%, 100%, 99% for BDM, and 94%, 99%, 94% and 99% for XCD. 9.6% of samples were ribotype 027. Algorithms may detect CDI with lower sensitivity compared to molecular methods in children. This may be related to low prevalence of NAP-1/ribotype 027.

Clinical and Microbiological Characteristics of Clostridium difficile Infection Among Hospitalized Children in the Netherlands

BACKGROUND

Little is known about pediatric Clostridium difficile infection (CDI) epidemiology. We describe the clinical and microbiological characteristics of CDI among hospitalized children in the Netherlands.

METHODS

Between May 2009 and May 2015, 26 hospitals registered characteristics of pediatric (aged 2-18 years) and adult (aged 18 years) CDI in a national sentinel surveillance study. Routine polymerase chain reaction (PCR) ribotyping and multiple-locus variable-number tandem-repeat analysis (MLVA) of selected strains was performed. Pediatric and adult results were compared using proportion and 95% confidence interval (CI). Time trend of pediatric CDI was evaluated using a mixed-effect Poisson model.

RESULTS

Pediatric CDIs were reported in 17 of the 26 participating hospitals (n = 135; 3% of all CDIs); the monthly number was constant over time. The median age of pediatric cases was 10 years (interquartile range, 4.7-14.5 years). Fifty-five percent of the children had community onset and 31% had severe CDI. Compared with adults (n = 4,556), complication and mortality rates were lower. Clostridium difficile PCR ribotype 265 (toxin A negative, B positive) was most prevalent in children (15%; 95% CI, 8.8%-24.0%) but rarely found in adults (1%; 95% CI, 0.9%-1.6%). This strain was rarely found in other countries, except for Belgium. MLVA showed genetic relatedness between three-fourths of pediatric and adult ribotype 265 strains, without a clear epidemiological link.

CONCLUSIONS

Pediatric CDI in hospitals has remained stable over the last 6 years and resulted in fewer complications than for adult CDI. Further studies are needed to elucidate the source and epidemiology of PCR ribotype 265, primarily found in children.

Rapid change of fecal microbiome and disappearance of Clostridium difficile in a colonized infant after transition from breast milk to cow milk

BACKGROUND

Clostridium difficile is the most common known cause of antibiotic-associated diarrhea. Upon the disturbance of gut microbiota by antibiotics, C. difficile establishes growth and releases toxins A and B, which cause tissue damage in the host. The symptoms of C. difficile infection disease range from mild diarrhea to pseudomembranous colitis and toxic megacolon. Interestingly, 10-50 % of infants are asymptomatic carriers of C. difficile. This longitudinal study of the C. difficile colonization in an infant revealed the dynamics of C. difficile presence in gut microbiota.

METHODS

Fifty fecal samples, collected weekly between 5.5 and 17 months of age from a female infant who was an asymptomatic carrier of C. difficile, were analyzed by 16S rRNA gene sequencing.

RESULTS

Colonization switching between toxigenic and non-toxigenic C. difficile strains as well as more than 100,000-fold fluctuations of C. difficile counts were observed. C. difficile toxins were detected during the testing period in some infant stool samples, but the infant never had diarrhea. Although fecal microbiota was stable during breast feeding, a dramatic and permanent change of microbiota composition was observed within 5 days of the transition from human milk to cow milk. A rapid decline and eventual disappearance of C. difficile coincided with weaning at 12.5 months. An increase in the relative abundance of Bacteroides spp., Blautia spp., Parabacteroides spp., Coprococcus spp., Ruminococcus spp., and Oscillospira spp. and a decrease of Bifidobacterium spp., Lactobacillus spp., Escherichia spp., and Clostridium spp. were observed during weaning. The change in microbiome composition was accompanied by a gradual increase of fecal pH from 5.5 to 7.

CONCLUSIONS

The bacterial groups that are less abundant in early infancy, and that increase in relative abundance after weaning, likely are responsible for the expulsion of C. difficile.

Clostridium difficile Infection in Special High-Risk Populations

Antibiotic use continues to be the most important risk factor for the development of Clostridium difficile infection (CDI) through disruption of the indigenous microbiota of the colon. This factor, together with environmental contamination, makes hospital and other healthcare facilities the perfect breeding ground for the infection. Several groups of patients are exposed to the hospital environment and, at the same time, affected by conditions that can make CDI more prevalent, more severe or make it present a different clinical picture. The list of such conditions appears too extensive to be reviewed in a single article. Nevertheless, several groups, including the critically ill, oncological patients, solid organ and hematopoietic transplant recipients, patients with inflammatory bowel disease, patients with kidney disease and pregnant women, have generated more attention and have been studied in more detail. On the other hand, pediatric patients constitute a controversial group because the large number of asymptomatic carriers makes interpretation of clinical findings and diagnostic tests difficult, as is the development of an appropriate approach to treatment. We present an in-depth discussion of CDI in these high-risk populations and we also review the issue of CDI in pediatric patients.