Impact of Multiplex Testing on the Identification of Pediatric Clostridiodes Difficile

A Multimodal Intervention to Reduce C. difficile Infections and Stool Testing

BACKGROUND AND OBJECTIVES

The introduction of multiplex gastrointestinal panels at our institution resulted in increased Clostridioides difficile (C. difficile) detection and stool test utilization. We aimed to reduce hospital-onset C. difficile infections (HO-CDIs), C. difficile detection, and overall stool testing by 20% within 1 year.

METHODS

We conducted a quality improvement project from 2018 to 2020 at a large children's hospital. Interventions included development of a C. difficile testing and treatment clinical care pathway, new options for gastrointestinal panel testing with or without C. difficile (results were suppressed if not ordered), clinical decision support tool to restrict testing, and targeted prevention efforts. Outcomes included the rate of HO-CDI (primary), C. difficile detection, and overall stool testing. All measures were evaluated monthly among hospitalized children per 10 000 patient-days (PDs) using statistical process-control charts. For balancing measures, we tracked suppressed C. difficile results that were released during real-time monitoring because of concern for true infection and C. difficile-related adverse events.

RESULTS

HO-CDI decreased by 55%, from 11 to 5 per 10 000 PDs. C. difficile detection decreased by 44%, from 18 to 10 per 10 000 PDs, and overall test utilization decreased by 29%, from 99 to 70 per 10 000 PDs. The decrease in stool tests resulted in annual savings of $55 649. Only 2.3% of initially suppressed positive C. difficile results were released, and no patients had adverse events.

CONCLUSIONS

Diagnostic stewardship strategies, coupled with an evidence-based clinical care pathway, can be used to decrease C. difficile and improve overall test utilization.

Factors Associated With Actionable Gastrointestinal Panel Results in Hospitalized Children

OBJECTIVES

There is uncertainty regarding which hospitalized patients with acute gastroenteritis (AGE) benefit from gastrointestinal panel (GIP) testing. Unnecessary testing may lead to increased costs, overdiagnosis, and overtreatment. In general, AGE management and outcomes are most impacted if an actionable (bacterial or parasitic) result is obtained. We aimed to assess which clinical reasons for ordering GIP testing ("order indications") and patient factors were associated with actionable results.

METHODS

This is a cross-sectional study of pediatric patients hospitalized between 2015 and 2018 at a large pediatric health care system with diarrhea and a GIP performed. Multivariable regression analysis was used to determine associations between actionable GIP results and order indication, stool frequency, and demographics. Findings were evaluated in patients with complex chronic conditions (CCC) and non-CCC patients.

RESULTS

There were 1124 GIPs performed in 967 encounters. Non-CCC patients had more actionable results than CCC patients, and reasons for testing differed. Across both cohorts, age ≥1 year old was positively associated with actionable results. For non-CCC patients, actionable results were associated with "diarrhea with blood or pus" order indication and nonwinter season; international travel was associated with non-Clostridioides difficile bacteria and parasites. No order indications were associated with actionable results for CCC patients.

CONCLUSIONS

Patient factors and order indications that may help identify children hospitalized for AGE with actionable GIP results include older age (regardless of CCC status), as well as bloody stools and international travel in previously healthy children. Prospective validation of these findings could help improve diagnostic stewardship and decrease unnecessary testing.

Host Immune Responses to Clostridioides difficile Infection and Potential Novel Therapeutic Approaches

Clostridioides difficile infection (CDI) is a leading nosocomial infection, posing a substantial public health challenge within the United States and globally. CDI typically occurs in hospitalized elderly patients who have been administered antibiotics; however, there has been a rise in the occurrence of CDI in the community among young adults who have not been exposed to antibiotics. C. difficile releases toxins, which damage large intestinal epithelium, leading to toxic megacolon, sepsis, and even death. Unfortunately, existing antibiotic therapies do not always prevent these consequences, with up to one-third of treated patients experiencing a recurrence of the infection. Host factors play a crucial role in the pathogenesis of CDI, and accumulating evidence shows that modulation of host immune responses may potentially alter the disease outcome. In this review, we provide an overview of our current knowledge regarding the role of innate and adaptive immune responses on CDI outcomes. Moreover, we present a summary of non-antibiotic microbiome-based therapies that can effectively influence host immune responses, along with immunization strategies that are intended to tackle both the treatment and prevention of CDI.

Clostridioides difficile Infection in Children: Recent Updates on Epidemiology, Diagnosis, Therapy

Clostridioides (formerly Clostridium) difficile is the most important infectious cause of antibiotic-associated diarrhea worldwide and a leading cause of healthcare-associated infection in the United States. The incidence of C. difficile infection (CDI) in children has increased, with 20 000 cases now reported annually, also posing indirect educational and economic consequences. In contrast to infection in adults, CDI in children is more commonly community-associated, accounting for three-quarters of all cases. A wide spectrum of disease severity ranging from asymptomatic carriage to severe diarrhea can occur, varying by age. Fulminant disease, although rare in children, is associated with high morbidity and even fatality. Diagnosis of CDI can be challenging as currently available tests detect either the presence of organism or disease-causing toxin but cannot distinguish colonization from infection. Since colonization can be high in specific pediatric groups, such as infants and young children, biomarkers to aid in accurate diagnosis are urgently needed. Similar to disease in adults, recurrence of CDI in children is common, affecting 20% to 30% of incident cases. Metronidazole has long been considered the mainstay therapy for CDI in children. However, new evidence supports the safety and efficacy of oral vancomycin and fidaxomicin as additional treatment options, whereas fecal microbiota transplantation is gaining popularity for recurrent infection. Recent advancements in our understanding of emerging epidemiologic trends and management of CDI unique to children are highlighted in this review. Despite encouraging therapeutic advancements, there remains a pressing need to optimize CDI therapy in children, particularly as it pertains to severe and recurrent disease.

Enteric Pathogen Testing Importance for Children with Acute Gastroenteritis: a Modified Delphi Study

The application of clinical diagnostics for gastroenteritis in children has implications for a broad collection of stakeholders, impacting clinical care, communicable disease control, and laboratory utilization. To support diagnostic stewardship as gastroenteritis testing options continue to advance, it is critical to understand which enteropathogens constitute priorities for testing across stakeholder groups. Using a modified Delphi technique, we elicited opinions of subject matter experts to determine clinical and public health testing priorities. There was a high level of overall agreement (≥80%) among stakeholders (final round n = 15) that testing was important for Campylobacter, Escherichia coli O157 and other Shiga toxin-producing E. coli, Salmonella, Shigella, Vibrio, Yersinia, norovirus, and rotavirus. Immunocompromised children were identified as a special population that warranted the additional testing of three to four bacterial and parasitic targets. To support these clinical and public health testing priorities, diagnostic stewardship strategies can be employed, such as educating clinicians, developing new decision support tools, and using multiplex testing in concert with selective result reporting and annotation. IMPORTANCE Children with diarrhea and vomiting who seek care can be infected with a wide variety of infectious agents. This study reports findings from a survey of clinical, public health, and laboratory subject matter experts on the infectious agents that are most important to test for. The majority agreed on the importance of testing children likely infected with several bacterial agents, as well as two common viruses. Although confirming a child is positive for a viral agent is unlikely to change clinical care, participants noted the importance of monitoring these viruses for public health purposes. To avoid over-testing children, however, these results should be used to support diagnostic stewardship strategies and design new decision support tools.

Updates and Opinions in Diagnosis and Treatment of Clostridiodes difficile in Pediatrics

Purpose of review

Clostridiodes difficile infection (CDI) has unique challenges for diagnosis and treatment in pediatrics. Though new antibiotics and biologics are being approved or developed for adults, most of the pediatric therapies still rely on multiple or extended antibiotic courses. This review aims to highlight emerging evidence and our clinical experience with CDI in children and can help inform readers' approach to pediatric CDI.

Recent findings

Use of fidaxomicin for CDI in pediatrics has been shown to be to be non-inferior to vancomycin and is associated with higher global cure rates and decreased risk of recurrence. Fecal microbiota transplant is a successful emerging therapy with cure rates of up to 90%, though safety alerts should be noted. Diagnostic laboratory testing for C. difficile remains a challenge as it still cannot definitively distinguish between colonization and true infection, and this is particularly relevant to pediatric patients as they have the highest rates of colonization.

Summary

The diagnosis and treatment of C. difficile infection in pediatrics remain challenging and recommendations lag behind advances made in the adult field. Recent data suggests that use of fidaxomicin both as treatment of first episode or recurrences may be beneficial in pediatrics just as in adults. At an experienced center, FMT is associated with high cure rates. Bezlotuxumab a monoclonal antibody to toxin B that is already recommended for use in adults is being studied in children and should be available for clinical use soon. Oral vancomycin prophylaxis is also an emerging strategy for high-risk patients. Finally, a possible vaccine may be on the horizon for pediatrics.

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.

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.

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.

Clinical Impact of a Diagnostic Gastrointestinal Panel in Children

OBJECTIVES

Many hospitals have transitioned from conventional stool diagnostics to rapid multiplex polymerase chain reaction gastrointestinal panels (GIP). The clinical impact of this testing has not been evaluated in children. In this study, we compare use, results, and patient outcomes between conventional diagnostics and GIP testing.

METHODS

This is a multicenter cross-sectional study of children who underwent stool testing from 2013 to 2017. We used bivariate analyses to compare test use, results, and patient outcomes, including length of stay (LOS), ancillary testing, and hospital charges, between the GIP era (24 months after GIP introduction) and conventional diagnostic era (historic control, 24 months before).

RESULTS

There were 12 222 tests performed in 8720 encounters. In the GIP era, there was a 21% increase in the proportion of children who underwent stool testing, with a statistically higher percentage of positive results (40% vs 11%), decreased time to result (4 vs 31 hours), and decreased time to treatment (11 vs 35 hours). Although there was a decrease in LOS by 2 days among those who received treatment of a bacterial and/or parasitic pathogen (5.1 vs 3.1; P < .001), this represented only 3% of tested children. In the overall population, there was no statistical difference in LOS, ancillary testing, or charges.

CONCLUSIONS

The GIP led to increased pathogen detection and faster results. This translated into improved outcomes for only a small subset of patients, suggesting that unrestricted GIP use leads to low-value care. Similar to other novel rapid diagnostic panels, there is a critical need for diagnostic stewardship to optimize GIP testing.

Diagnosis and management of paediatric Clostridioides difficile infection in a tertiary centre: A prospective audit

AIM

The optimisation of diagnosis and management of paediatric Clostridioides (formerly Clostridium) difficile (C. difficile) infection (CDI) has importance on multiple levels, from individual patient to population disease management and infection control. This study aimed to evaluate current practice at a paediatric tertiary hospital against Australasian Society for Infectious Diseases 2016 guidelines.

METHODS

Prospective audit was undertaken. All positive C. difficile tests (by two step immunoassay then polymerase chain reaction) over 6 month period were reviewed for appropriateness of testing, including review of clinical characteristics and treatment of appropriately requested positive tests (CDI cases). Consecutive test requests for C. difficile over 2 month period were reviewed for appropriateness of testing.

RESULTS

Of 70 consecutive test requests, 64 met laboratory criteria for processing. Of these, 31 (48%) out of 64 were asymptomatic or had clinically insignificant or laxative-associated diarrhoea. Overall, 44 (63%) out of 70 were deemed inappropriate requests. Of 45 positive tests, 17 (38%) were appropriately requested. Amongst inappropriate requests, 13 (46%) out of 28 were treated; those aged >2 years were significantly more likely to be treated (P < 0.05). Thirteen children were treated unnecessarily. Only one out of seven positive tests in infants (<1 year) was appropriately requested. Haematology/oncology patients accounted for 41% of cases. Treatment was in accordance with guidelines in 58% of cases.

CONCLUSIONS

Inappropriate testing for C. difficile and variable clinical response to positive tests have sequelae including unnecessary antibiotics for hospitalised children. Areas for improvement have been identified and this study confirms the need for establishment of national paediatric CDI guidelines with increased awareness of these by clinicians.