Predictors of serious bacterial infections using serum biomarkers in an infant population aged 0 to 90 days: a prospective cohort study

Protocol for the diagnostic performance of C reactive protein, procalcitonin and interleukin-6 for serious bacterial infections among children ≤36 months old presenting with fever without source: a systematic review and meta-analysis

INTRODUCTION

The management of fever without source in children ≤36 months old remains a diagnostic challenge as the underlying aetiologies can vary from self-limiting viral infections to serious bacterial infections (SBIs). Biomarkers such as C reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6) have varying thresholds in the prediction of SBIs due to differences in SBI definitions, SBI prevalence, patient characteristics and timing of presentation. This protocol describes a systematic review and meta-analysis that aims to determine the thresholds at which CRP, PCT and IL-6 can perform optimally in distinguishing the presence of SBIs in children ≤36 months old, as well as to determine their performances in early detection of bacterial infections within 48 hours of fever onset.

METHODS AND ANALYSIS

We will systematically search electronic databases including MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane CENTRAL, EMBASE, CINAHL (Cumulative Index to Nursing and Allied Health Literature) and Science Citation Index from 1 July 2023 to 31 July 2023. We will include studies that report the diagnostic accuracy of CRP, PCT and IL-6 in detecting SBIs in children aged ≤36 months presenting with fever without apparent source. Randomised controlled trials (RCTs) and non-randomised studies including non-RCTs and controlled before-and-after studies will be included. A meta-analysis will be performed and diagnostic performances of these biomarkers will be reported.

ETHICS AND DISSEMINATION

The results of this study will provide guidance on clinical decision-making in young children presenting with fever without source. Ethics approval will not be required for this study. The authors aim to publish the findings in a peer-reviewed journal as well as present at international conferences.

PROSPERO REGISTRATION NUMBER

CRD42023439093.

The evolving value of older biomarkers in the clinical diagnosis of pediatric sepsis

Sepsis remains the leading cause of childhood mortality worldwide. The evolving definition of pediatric sepsis is extrapolated from adult studies. Although lacking formal validation in the pediatric population, this working definition has historically proven its clinical utility. Prompt identification of pediatric sepsis is challenging as clinical picture is often variable. Timely intervention is crucial for optimal outcome, thus biomarkers are utilized to aid in immediate, yet judicious, diagnosis of sepsis. Over time, their use in sepsis has expanded with discovery of newer biomarkers that include genomic bio-signatures. Despite recent scientific advances, there is no biomarker that can accurately diagnose sepsis. Furthermore, older biomarkers are readily available in most institutions while newer biomarkers are not. Hence, the latter's clinical value in pediatric sepsis remains theoretical. Albeit promising, scarce data on newer biomarkers have been extracted from research settings making their clinical value unclear. As interest in newer biomarkers continue to proliferate despite their ambiguous clinical use, the literature on older biomarkers in clinical settings continue to diminish. Thus, revisiting the evolving value of these earliest biomarkers in optimizing pediatric sepsis diagnosis is warranted. This review focuses on the four most readily available biomarkers to bedside clinicians in diagnosing pediatric sepsis. IMPACT: The definition of pediatric sepsis remains an extrapolation from adult studies. Older biomarkers that include C-reactive protein, procalcitonin, ferritin, and lactate are the most readily available biomarkers in most pediatric institutions to aid in the diagnosis of pediatric sepsis. Older biomarkers, although in varying levels of reliability, remain to be useful clinical adjuncts in the diagnosis of pediatric sepsis if used in the appropriate clinical context. C-reactive protein and procalcitonin are more sensitive and specific among these older biomarkers in diagnosing pediatric sepsis although evidence varies in different age groups and clinical scenarios.

Validation and comparison of the PECARN rule, Step-by-Step approach and Lab-score for predicting serious and invasive bacterial infections in young febrile infants

Introduction: Differentiating infants with serious bacterial infections (SBIs) or invasive bacterial infections (IBIs) from those without remains a challenge. We sought to compare the diagnostic performances of single biomarkers (absolute neutrophil count [ANC], C-reactive protein [CRP] and procalcitonin [PCT]) and 4 diagnostic approaches comprising Lab-score, Step-by-Step approach (original and modified) and Pediatric Emergency Care Applied Research Network (PECARN) rule. Method: This is a prospective cohort study involving infants 0–90 days of age who presented to an emergency department from July 2020 to August 2021. SBIs were defined as bacterial meningitis, bacteraemia and/or urinary tract infections. IBIs were defined as bacteraemia and/or bacterial meningitis. We evaluated the performances of Lab-score, Step-by-Step (original and modified) and PECARN rule in predicting SBIs and IBIs. Results: We analysed a total of 258 infants, among whom 86 (33.3%) had SBIs and 9 (3.5%) had IBIs. In predicting SBIs, ANC ≥4.09 had the highest sensitivity and negative predictive value (NPV), while PCT ≥1.7 had the highest specificity and positive predictive value (PPV). CRP ≥20 achieved the highest area under receiver operating characteristic curve (AUC) of 0.741 (95% confidence interval [CI] 0.672–0.810). The Step-by-Step (original) approach had the highest sensitivity (97.7%). Lab-score had the highest AUC of 0.695 (95% CI 0.621–0.768), compared to PECARN rule at 0.625 (95% CI 0.556–0.694) and Step-by-Step (original) at 0.573 (95% CI 0.502–0.644). In predicting IBIs, PCT ≥1.7 had the highest sensitivity, specificity, PPV and NPV. The Step-by-Step (original and modified) approach had the highest sensitivity of 100%. Lab-score had the highest AUC of 0.854 (95% CI 0.731–0.977) compared to PECARN rule at 0.589 (95% CI 0.420–0.758) and Step-by-Step at 0.562 (95% CI 0.392–0.732). Conclusion: CRP strongly predicted SBIs, and PCT strongly predicted IBI. The Step-by-Step approach had the highest sensitivity and NPV, while Lab-score had the highest specificity and AUC in predicting SBIs and IBIs. Keywords: Biomarkers, diagnostic approaches, febrile infants, Lab-score, PECARN rule, Step-by-Step approach

Establishment of a predictive model for purulent meningitis in preterm infants

BACKGROUND

Purulent meningitis (PM) is an important cause of mortality and morbidity in the newborn population throughout the world. The subtle of specific clinical signs and low success rates of lumbar puncture make diagnosis of PM more difficult in preterm than in older children. The objective of this study was to establish a predict model for preterm PM in hopes of helping clinicians develop new diagnostic and treatment strategies.

METHODS

Premature infants who were admitted to The First Affiliated Hospital of Zhengzhou University from September 2017 to March 2020 were enrolled in this study. All the patients underwent lumbar puncture. We collected data encompassing maternal diseases and neonatal clinical features. Cerebrospinal fluid (CSF) culture is the gold standard for diagnosing meningitis. The PM was diagnosed according to the diagnostic criteria. All statistical analyses were performed using R 3.63 (https://www.r-project.org/). Logistic regression and least absolute shrinkage and selection operator (LASSO) regression analyses were used to establish a risk prediction model of PM. The Brier score, calibration slope, and concordance (C)-index were used to verify the accuracy of prediction model.

RESULTS

A total of 168 preterm infants were enrolled in this study, 80 boys and 88 girls, the gestational age (GA) was 26.43-36.86 weeks (32.45±2.79 weeks), the birth weight (BW) was 700-3,400 g (1,814.05±568.84 g). There were 77 preterm infants with PM while 91 without. We identified seven variables as independent risk factors for PM in preterm infants by LASSO analysis [the optimal λ was 0.080960, and log(λ) = -2.5138], including procalcitonin (PCT) on the 1st day after birth, prenatal glucocorticoid use, albumin, the 1-minute Apgar score, the use of non-invasive biphasic positive airway pressure, hemoglobin, and sex. These were used to construct a risk prediction nomogram and verified its accuracy. The Brier score was 0.17, the calibration slope was 0.966, and the concordance index was 0.82018.

CONCLUSIONS

Our prediction model could predict the risk of PM in preterm infants. Using this prediction model, it may be able to provide reference to determine whether lumbar puncture is performed and whether antibiotics are applied as soon as possible.

Febrile children with comorbidities at the emergency department - a multicentre observational study

We aimed to describe characteristics and management of children with comorbidities attending European emergency departments (EDs) with fever. MOFICHE (Management and Outcome of Fever in children in Europe) is a prospective multicentre study (12 European EDs, 8 countries). Febrile children with comorbidities were compared to those without in terms of patient characteristics, markers of disease severity, management, and diagnosis. Comorbidity was defined as a chronic underlying condition that is expected to last > 1 year. We performed multivariable logistic regression analysis, displaying adjusted odds ratios (aOR), adjusting for patient characteristics. We included 38,110 patients, of whom 5906 (16%) had comorbidities. Most common comorbidities were pulmonary, neurologic, or prematurity. Patients with comorbidities more often were ill appearing (20 versus 16%, p < 0.001), had an ED-Paediatric Early Warning Score of > 15 (22 versus 12%, p < 0.001), or a C-reactive protein > 60 mg/l (aOR 1.4 (95%CI 1.3-1.6)). They more often required life-saving interventions (aOR 2.7, 95% CI 2.2-3.3), were treated with intravenous antibiotics (aOR 2.3, 95%CI 2.1-2.5), and were admitted to the ward (aOR 2.2, 95%CI 2.1-2.4) or paediatric intensive care unit (PICU) (aOR 5.5, 95% CI 3.8-7.9). They were more often diagnosed with serious bacterial infections (aOR 1.8, 95%CI 1.7-2.0), including sepsis/meningitis (aOR 4.6, 95%CI 3.2-6.7). Children most at risk for sepsis/meningitis were children with malignancy/immunodeficiency (aOR 14.5, 8.5-24.8), while children with psychomotor delay/neurological disease were most at risk for life-saving interventions (aOR 5.3, 4.1-6.9) or PICU admission (aOR 9.7, 6.1-15.5).

CONCLUSIONS

Our data show how children with comorbidities are a population at risk, as they more often are diagnosed with bacterial infections and more often require PICU admission and life-saving interventions.

WHAT IS KNOWN

• While children with comorbidity constitute a large part of ED frequent flyers, they are often excluded from studies.

WHAT IS NEW

• Children with comorbidities in general are more ill upon presentation than children without comorbidities. • Children with comorbidities form a heterogeneous group; specific subgroups have an increased risk for invasive bacterial infections, while others have an increased risk of invasive interventions such as PICU admission, regardless of the cause of the fever.