Bone health in children with Angelman syndrome at the ENCORE Expertise Center.

Angelman syndrome (AS) is a rare genetic disorder due to lack of UBE3A function on chromosome 15q11.2q13 caused by a deletion, uniparental paternal disomy (UPD), imprinting center disorder (ICD), or pathological variant of the UBE3A gene. AS is characterized by developmental delay, epilepsy, and lack of speech. Although fractures are observed frequently in our clinical practice, there are few studies on bone health in AS. The aim of this study is to investigate bone health in children with AS. In this prospective cohort study, we describe bone health in 91 children with AS visiting the ENCORE Expertise Center for AS between April 2010 and December 2021. Bone health was assessed with the bone health index (BHI) in standard deviation score (SDS) measured by digital radiogrammetry of the left hand using BoneXpert software. Risk factors analyzed were age, sex, genetic subtype, epilepsy, anti-seizure medication use, mobility, body mass index (BMI), and onset of puberty. Children with AS had a mean BHI of -1.77 SDS (SD 1.4). A significantly lower BHI was found in children with a deletion (-2.24 SDS) versus non-deletion (-1.02 SDS). Other factors associated with reduced BHI-SDS were inability to walk and late onset of puberty. Children with a history of one or more fractures (22%) had a significantly lower BHI than children without fractures (-2.60 vs -1.56 SDS). Longitudinal analysis showed a significant decrease in BHI-SDS with age in all genetic subtypes.  Conclusions: Children with AS have a reduced bone health. Risk factors are deletion genotype, no independent walking, and late onset of puberty. Bone health decreased significantly with age. What is Known: • Children with neurological disorders often have a low bone health and higher risk of fractures. • Little is known about bone health in children with Angelman syndrome (AS). What is New: • Children with AS showed a reduced bone health and this was significantly associated with having a deletion, not being able to walk independently, and late onset of puberty. • Longitudinal analysis showed a significant decrease in bone health as children got older.

Which low urgent triaged febrile children are suitable for a fast track? An observational European study.

BACKGROUND: The number of paediatric patients visiting the ED with non-urgent problems is increasing, leading to poor patient flow and ED crowding. Fast track aims to improve the efficiency of evaluation and discharge of low acuity patients. We aimed to identify which febrile children are suitable for a fast track based on presenting symptoms and management. METHODS: This study is part of the Management and Outcome of Fever in children in Europe study, which is an observational study including routine data of febrile children <18 years attending 12 European EDs. We included febrile, low urgent children (those assigned a triage acuity of either 'standard' or 'non-urgent' using the Manchester Triage System) and defined children as suitable for fast track when they have minimal resource use and are discharged home. Presenting symptoms consisted of neurological (n=237), respiratory (n=8476), gastrointestinal (n=1953) and others (n=3473, reference group). Multivariable logistic regression analyses regarding presenting symptoms and management (laboratory blood testing, imaging and admission) were performed with adjustment for covariates: patient characteristics, referral status, previous medical care, previous antibiotic use, visiting hours and ED setting. RESULTS: We included 14 139 children with a median age of 2.7 years (IQR 1.3-5.2). The majority had respiratory symptoms (60%), viral infections (50%) and consisted of self-referrals (69%). The neurological group received imaging more often (adjusted OR (aOR) 1.8, 95% CI 1.1 to 2.9) and were admitted more frequently (aOR 1.9, 95% CI 1.4 to 2.7). The respiratory group had fewer laboratory blood tests performed (aOR 0.6, 95% CI 0.5 to 0.7), were less frequently admitted (aOR 0.6, 95% CI 0.5 to 0.7), but received imaging more often (aOR 1.8, 95% CI 1.6 to 2.0). Lastly, the gastrointestinal group had more laboratory blood tests performed (aOR 1.2. 95% CI 1.1 to 1.4) and were admitted more frequently (aOR 1.4, 95% CI 1.2 to 1.6). CONCLUSION: We determined that febrile children triaged as low urgent with respiratory symptoms were most suitable for a fast track. This study provides evidence for which children could be triaged to a fast track, potentially improving overall patient flow at the ED.

Elevated High-Sensitivity Troponin and NT-proBNP Values in Febrile Children.

OBJECTIVES: The COVID-19 pandemic and subsequent rise of multisystem inflammatory syndrome in children have raised interest in high-sensitivity troponin (hs-TnT) and N-terminal probrain natriuretic peptide (NT-proBNP) because these have been found to be elevated in many cases of multisystem inflammatory syndrome in children. Our aim was to study hs-TnT and NT-proBNP concentrations in febrile children not affected by COVID-19. METHODS: We retrospectively measured cardiac markers, hs-TnT, and NT-proBNP in leftover blood samples of febrile children (0-18 years) diagnosed and treated in a single-center emergency department (ED) (N = 67) and pediatric intensive care unit (PICU) (N = 19) that participated in a multicenter, prospective study of infection biomarkers (PERFORM). RESULTS: Concentrations of hs-TnT, median 1.8 ng/L (interquartile range [IQR], 0.0-15.1), and NT-proBNP, 194 pg/mL (IQR, 54.9-706), were higher in febrile children than in controls (N = 25, hs-TnT 0.0 [IQR, 0-0]; NT-proBNP 56.3 [IQR, 29.7-109], both P < 0.001), whereas PICU patients had higher concentrations (hs-TnT 15.1 [IQR, 10.3-102] and NT-proBNP 828 [IQR, 657-4712], both P < 0.001) than ED patients (hs-TnT 0 [IQR, 0-7.4] and NT-proBNP 104 [IQR, 39.5-363]). No differences were found between viral and bacterial infections. Highest concentrations were found in children with either comorbidity predisposing to elevated concentrations (eg, chronic cardiac or renal disease) or children with critical illness or multiorgan failure such as those with septic shock. CONCLUSIONS: Concentrations of hs-TnT and NT-proBNP are often elevated in febrile children with different causes of fever. Concentrations were higher in children admitted to the PICU than in children attending the ED, and seem to reflect disease severity rather than the underlying cause of fever.

Respective roles of non-pharmaceutical interventions in bronchiolitis outbreaks: an interrupted time-series analysis based on a multinational surveillance system.

BACKGROUND: Bronchiolitis is a major source of morbimortality among young children worldwide. Non-pharmaceutical interventions (NPIs) implemented to reduce the spread of severe acute respiratory syndrome coronavirus 2 may have had an important impact on bronchiolitis outbreaks, as well as major societal consequences. Discriminating between their respective impacts would help define optimal public health strategies against bronchiolitis. We aimed to assess the respective impact of each NPI on bronchiolitis outbreaks in 14 European countries. METHODS: We conducted a quasi-experimental interrupted time-series analysis based on a multicentre international study. All children diagnosed with bronchiolitis presenting to the paediatric emergency department of one of 27 centres from January 2018 to March 2021 were included. We assessed the association between each NPI and change in the bronchiolitis trend over time by seasonally adjusted multivariable quasi-Poisson regression modelling. RESULTS: In total, 42 916 children were included. We observed an overall cumulative 78% (95% CI -100- -54%; p<0.0001) reduction in bronchiolitis cases following NPI implementation. The decrease varied between countries from -97% (95% CI -100- -47%; p=0.0005) to -36% (95% CI -79-7%; p=0.105). Full lockdown (incidence rate ratio (IRR) 0.21 (95% CI 0.14-0.30); p<0.001), secondary school closure (IRR 0.33 (95% CI 0.20-0.52); p<0.0001), wearing a mask indoors (IRR 0.49 (95% CI 0.25-0.94); p=0.034) and teleworking (IRR 0.55 (95% CI 0.31-0.97); p=0.038) were independently associated with reducing bronchiolitis. CONCLUSIONS: Several NPIs were associated with a reduction of bronchiolitis outbreaks, including full lockdown, school closure, teleworking and facial masking. Some of these public health interventions may be considered to further reduce the global burden of bronchiolitis.

Multiple sclerosis risk variants influence the peripheral B-cell compartment early in life in the general population.

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) is associated with abnormal B-cell function, and MS genetic risk alleles affect multiple genes that are expressed in B cells. However, how these genetic variants impact the B-cell compartment in early childhood is unclear. In the current study, we aim to assess whether polygenic risk scores (PRSs) for MS are associated with changes in the blood B-cell compartment in children from the general population. METHODS: Six-year-old children from the population-based Generation R Study were included. Genotype data were used to calculate MS-PRSs and B-cell subset-enriched MS-PRSs, established by designating risk loci based on expression and function. Analyses of variance were performed to examine the effect of MS-PRSs on total B-cell numbers (n = 1261) as well as naive and memory subsets (n = 675). RESULTS: After correction for multiple testing, no significant associations were observed between MS-PRSs and total B-cell numbers and frequencies of subsets therein. A naive B-cell-MS-PRS (n = 26 variants) was significantly associated with lower relative, but not absolute, naive B-cell numbers (p = 1.03 × 10-4 and p = 0.82, respectively), and higher frequencies and absolute numbers of CD27+ memory B cells (p = 8.83 × 10-4 and p = 4.89 × 10-3 , respectively). These associations remained significant after adjustment for Epstein-Barr virus seropositivity and the HLA-DRB1*15:01 genotype. CONCLUSIONS: The composition of the blood B-cell compartment is associated with specific naive B-cell-associated MS risk variants during childhood, possibly contributing to MS pathophysiology later in life. Cell subset-specific PRSs may offer a more sensitive tool to define the impact of genetic risk on the immune system in diseases such as MS.

Emergency medical services utilisation among febrile children attending emergency departments across Europe: an observational multicentre study.

Children constitute 6-10% of all patients attending the emergency department (ED) by emergency medical services (EMS). However, discordant EMS use in children occurs in 37-61% with fever as an important risk factor. We aimed to describe EMS utilisation among febrile children attending European EDs. This study is part of an observational multicentre study assessing management and outcome in febrile children up to 18 years (MOFICHE) attending twelve EDs in eight European countries. Discordant EMS use was defined as the absence of markers of urgency including intermediate/high triage urgency, advanced diagnostics, treatment, and admission in children transferred by EMS. Multivariable logistic regression analyses were performed for the association between (1) EMS use and markers of urgency, and (2) patient characteristics and discordant EMS use after adjusting all analyses for the covariates age, gender, visiting hours, presenting symptoms, and ED setting. A total of 5464 (15%, range 0.1-42%) children attended the ED by EMS. Markers of urgency were more frequently present in the EMS group compared with the non-EMS group. Discordant EMS use occurred in 1601 children (29%, range 1-59%). Age and gender were not associated with discordant EMS use, whereas neurological symptoms were associated with less discordant EMS use (aOR 0.2, 95%CI 0.1-0.2), and attendance out of office hours was associated with more discordant EMS use (aOR 1.6, 95%CI 1.4-1.9). Settings with higher percentage of self-referrals to the ED had more discordant EMS use (p < 0.05).  Conclusion: There is large practice variation in EMS use in febrile children attending European EDs. Markers of urgency were more frequently present in children in the EMS group. However, discordant EMS use occurred in 29%. Further research is needed on non-medical factors influencing discordant EMS use in febrile children across Europe, so that pre-emptive strategies can be implemented. What is Known: •Children constitute around 6-10% of all patients attending the emergency department by emergency medical services. •Discordant EMS use occurs in 37-61% of all children, with fever as most common presenting symptom for discordant EMS use in children. What is New: •There is large practice variation in EMS use among febrile children across Europe with discordance EMS use occurring in 29% (range 1-59%), which was associated with attendance during out of office hours and with settings with higher percentage of self-referrals to the ED. •Future research is needed focusing on non-medical factors (socioeconomic status, parental preferences and past experience, healthcare systems, referral pathways, out of hours services provision) that influence discordant EMS use in febrile children across Europe.

Anti-tissue transglutaminase antibodies (TG2A) positivity and the risk of vitamin D deficiency among children - a cross-sectional study in the generation R cohort.

BACKGROUND: Suboptimal vitamin D status is common in people with celiac disease (CeD), a disease that can be characterized by the presence of serum anti-tissue transglutaminase antibodies (TG2A) (i.e., TG2A positivity). To date, it remains unclear whether childhood TG2A positivity is associated with vitamin D status and how this potential association can be explained by other factors than malabsorption only, since vitamin D is mainly derived from exposure to sunlight. The aim of our study was therefore to assess whether childhood TG2A positivity is associated with vitamin D concentrations, and if so, to what extent this association can be explained by sociodemographic and lifestyle factors. METHODS: This cross-sectional study was embedded in the Generation R Study, a population-based prospective cohort. We measured serum anti-tissue transglutaminase antibodies (TG2A) concentrations and serum 25-hydroxyvitamin D (25(OH)D) concentrations of 3994 children (median age of 5.9 years). Children with serum TG2A concentrations ≥ 7 U/mL were considered TG2A positive. To examine associations between TG2A positivity and 25(OH)D concentrations, we performed multivariable linear regression, adjusted for sociodemographic and lifestyle factors. RESULTS: Vitamin D deficiency (serum 25(OH)D < 50 nmol/L) was found in 17 out of 54 TG2A positive children (31.5%), as compared to 1182 out of 3940 TG2A negative children (30.0%). Furthermore, TG2A positivity was not associated with 25(OH)D concentrations (ß -2.20; 95% CI -9.72;5.33 for TG2A positive vs. TG2A negative children), and this did not change after adjustment for confounders (ß -1.73, 95% CI -8.31;4.85). CONCLUSIONS: Our findings suggest there is no association between TG2A positivity and suboptimal vitamin D status in the general pediatric population. However, the overall prevalence of vitamin D deficiency in both populations was high, suggesting that screening for vitamin D deficiency among children, regardless of TG2A positivity, would be beneficial to ensure early dietary intervention if needed.

European study confirms the combination of fever and petechial rash as an important warning sign for childhood sepsis and meningitis.

AIM: This study investigated febrile children with petechial rashes who presented to European emergency departments (EDs) and investigated the role that mechanical causes played in diagnoses. METHODS: Consecutive patients with fever presenting to EDs in 11 European emergency departments in 2017-2018 were enrolled. The cause and focus of infection were identified and a detailed analysis was performed on children with petechial rashes. The results are presented as odds ratios (OR) with 95% confidence intervals (CI). RESULTS: We found that 453/34010 (1.3%) febrile children had petechial rashes. The focus of the infection included sepsis (10/453, 2.2%) and meningitis (14/453, 3.1%). Children with a petechial rash were more likely than other febrile children to have sepsis or meningitis (OR 8.5, 95% CI 5.3-13.1) and bacterial infections (OR 1.4, 95% CI 1.0-1.8) as well as need for immediate life-saving interventions (OR 6.6, 95% CI 4.4-9.5) and intensive care unit admissions (OR 6.5, 95% CI 3.0-12.5). CONCLUSION: The combination of fever and petechial rash is still an important warning sign for childhood sepsis and meningitis. Ruling out coughing and/or vomiting was insufficient to safely identify low-risk patients.

Parental help-seeking behaviour for, and care of, a sick or injured child during the COVID-19 pandemic: a European online survey.

BACKGROUND: Globally, the COVID-19 pandemic had a huge impact on patients and healthcare systems. A decline in paediatric visits to healthcare settings was observed, which might have been due to lower incidence of injury and infectious illness, changes in healthcare services and parental concern. The aim of our study was to examine parental experiences of help-seeking for, and care of, a sick or injured child during COVID-19 lockdown periods in five European countries with different healthcare systems in place. METHODS: An online survey for parents with a child with any kind or illness of injury during COVID-19 lockdowns was circulated through social media in five European countries: Italy, Spain, Sweden, the Netherlands, and the United Kingdom. Parents living in one of these countries with self-identification of a sick or injured child during COVID-19 lockdown periods were eligible to fill in the survey. Descriptive statistics were used for the level of restrictions per country, children's characteristics, family characteristics and reported help-seeking behaviour of parents prior to the lockdown and their real experience during the lockdown. The free text data was subjected to thematic analysis. RESULTS: The survey was fully completed by 598 parents, ranging from 50 to 198 parents per country, during varying lockdown periods from March 2020 until May 2022. Parents who completed the survey were not deterred from seeking medical help for their sick or injured child during the COVID-19 pandemic. This finding was comparable in five European countries with different healthcare systems in place. Thematic analysis identified three main areas: parental experiences of access to healthcare, changes in parents' help-seeking behaviours for a sick or injured child during lockdowns, and the impact of caring for a sick or injured child during the lockdowns. Parents reported limited access to non-urgent care services and were anxious about either their child or themselves catching COVID-19. CONCLUSION: This insight into parental perspectives of help-seeking behaviour and care for a sick or injured child during COVID-19 lockdowns could inform future strategies to improve access to healthcare, and to provide parents with adequate information concerning when and where to seek help and support during pandemics.

Presentations of children to emergency departments across Europe and the COVID-19 pandemic: A multinational observational study.

BACKGROUND: During the initial phase of the Coronavirus Disease 2019 (COVID-19) pandemic, reduced numbers of acutely ill or injured children presented to emergency departments (EDs). Concerns were raised about the potential for delayed and more severe presentations and an increase in diagnoses such as diabetic ketoacidosis and mental health issues. This multinational observational study aimed to study the number of children presenting to EDs across Europe during the early COVID-19 pandemic and factors influencing this and to investigate changes in severity of illness and diagnoses. METHODS AND FINDINGS: Routine health data were extracted retrospectively from electronic patient records of children aged 18 years and under, presenting to 38 EDs in 16 European countries for the period January 2018 to May 2020, using predefined and standardized data domains. Observed and predicted numbers of ED attendances were calculated for the period February 2020 to May 2020. Poisson models and incidence rate ratios (IRRs), using predicted counts for each site as offset to adjust for case-mix differences, were used to compare age groups, diagnoses, and outcomes. Reductions in pediatric ED attendances, hospital admissions, and high triage urgencies were seen in all participating sites. ED attendances were relatively higher in countries with lower SARS-CoV-2 prevalence (IRR 2.26, 95% CI 1.90 to 2.70, p < 0.001) and in children aged <12 months (12 to <24 months IRR 0.86, 95% CI 0.84 to 0.89; 2 to <5 years IRR 0.80, 95% CI 0.78 to 0.82; 5 to <12 years IRR 0.68, 95% CI 0.67 to 0.70; 12 to 18 years IRR 0.72, 95% CI 0.70 to 0.74; versus age <12 months as reference group, p < 0.001). The lowering of pediatric intensive care admissions was not as great as that of general admissions (IRR 1.30, 95% CI 1.16 to 1.45, p < 0.001). Lower triage urgencies were reduced more than higher triage urgencies (urgent triage IRR 1.10, 95% CI 1.08 to 1.12; emergent and very urgent triage IRR 1.53, 95% CI 1.49 to 1.57; versus nonurgent triage category, p < 0.001). Reductions were highest and sustained throughout the study period for children with communicable infectious diseases. The main limitation was the retrospective nature of the study, using routine clinical data from a wide range of European hospitals and health systems. CONCLUSIONS: Reductions in ED attendances were seen across Europe during the first COVID-19 lockdown period. More severely ill children continued to attend hospital more frequently compared to those with minor injuries and illnesses, although absolute numbers fell. TRIAL REGISTRATION: ISRCTN91495258 https://www.isrctn.com/ISRCTN91495258.

Improving the safety of the Manchester triage system for children with congenital heart disease.

This study is a prospective evaluation of the validity of a Manchester triage system (MTS) modification for detecting under-triaged pediatric patients with congenital heart disease (CHD). Children with CHD visiting the emergency unit of the Department of Pediatrics and Adolescent Medicine, University Hospital Vienna in 2014 were included. The MTS modification updated the prioritization of patients with complex syndromic diseases, specific symptoms related to chronic diseases, decreased general condition (DGC), profound language impairment, unknown medical history, or special needs. A four-level outcome severity index based on diagnostic and therapeutic interventions, admission to hospital, and follow-up strategies was defined as a reference standard for the correct clinical classification of the MTS urgency level. Of the 19,264 included children, 940 had CHD. Of this group, 266 fulfilled the inclusion criteria for the modified triage method. The MTS modification was significantly more often applied in under-triaged (65.9%) than correctly or over-triaged (25%) children with CHD (p-value χ2 test < 0.0001, OR 5.848, 95% CI: 3.636-9.6). CONCLUSION: The MTS urgency level upgrade modification could reduce under-triage in children with CHD. Applying a safety strategy concept to the MTS could mitigate under-triage in such a high-risk patient group. WHAT IS KNOWN: • The Manchester triage system is considered to be valid and reliable but tends to over-triage. • A study by Seiger et al. showed poor performance in children with chronic illnesses, especially in children with cardiovascular diseases. WHAT IS NEW: • The MTS modification with one urgency level upgrade could decrease under-triage in children with congenital heart disease. • As reference standard a four level outcome severity index (OSI) was established to include diagnostic investigations, medical interventions, hospital admission or follow up visits in the assessment.

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.

Guideline adherence in febrile children below 3 months visiting European Emergency Departments: an observational multicenter study.

Febrile children below 3 months have a higher risk of serious bacterial infections, which often leads to extensive diagnostics and treatment. There is practice variation in management due to differences in guidelines and their usage and adherence. We aimed to assess whether management in febrile children below 3 months attending European Emergency Departments (EDs) was according to the guidelines for fever. This study is part of the MOFICHE study, which is an observational multicenter study including routine data of febrile children (0-18 years) attending twelve EDs in eight European countries. In febrile children below 3 months (excluding bronchiolitis), we analyzed actual management compared to the guidelines for fever. Ten EDs applied the (adapted) NICE guideline, and two EDs applied local guidelines. Management included diagnostic tests, antibiotic treatment, and admission. We included 913 children with a median age of 1.7 months (IQR 1.0-2.3). Management per ED varied as follows: use of diagnostic tests 14-83%, antibiotic treatment 23-54%, admission 34-86%. Adherence to the guideline was 43% (374/868) for blood cultures, 29% (144/491) for lumbar punctures, 55% (270/492) for antibiotic prescriptions, and 67% (573/859) for admission. Full adherence to these four management components occurred in 15% (132/868, range 0-38%), partial adherence occurred in 56% (484/868, range 35-77%). CONCLUSION: There is large practice variation in management. The guideline adherence was limited, but highest for admission which implies a cautious approach. Future studies should focus on guideline revision including new biomarkers in order to optimize management in young febrile children. WHAT IS KNOWN: • Febrile children below 3 months have a higher risk of serious bacterial infections, which often leads to extensive diagnostics and treatment. • There is practice variation in management of young febrile children due to differences in guidelines and their usage and adherence. WHAT IS NEW: • Full guideline adherence is limited, whereas partial guideline adherence is moderate in febrile children below 3 months across Europe. • Guideline revision including new biomarkers is needed to improve management in young febrile children.

A population-based study on associations of stool microbiota with atopic diseases in school-age children.

BACKGROUND: Infants with less diverse gut microbiota seem to have higher risks of atopic diseases in early life, but any associations at school age are unclear. OBJECTIVES: This study sought to examine the associations of diversity, relative abundance, and functional pathways of stool microbiota with atopic diseases in school-age children. METHODS: We performed a cross-sectional study within an existing population-based prospective cohort among 1440 children 10 years of age. On stool samples, 16S ribosomal RNA gene sequencing was performed, and taxonomic and functional tables were produced. Physician-diagnosed eczema, allergy, and asthma were measured by questionnaires, allergic sensitization by skin prick tests, and lung function by spirometry. RESULTS: The α-diversity of stool microbiota was associated with a decreased risk of eczema (odds ratio [OR], 0.98; 95% CI, 0.97, 1.00), and ß-diversity was associated with physician-diagnosed inhalant allergy (R2 = 0.001; P = .047). Lachnospiraceae, Ruminococcaceae_UCG-005, and Christensenellaceae_R-7_group species were associated with decreased risks of eczema, inhalant allergic sensitization, and physician-diagnosed inhalant allergy (OR range, 0.88-0.94; 95% CI range, 0.79-0.96 to 0.88-0.98), while Agathobacter species were associated with an increased risk of physician-diagnosed inhalant allergy (OR, 1.23; 95% CI, 1.08-1.42). Functional pathways related to heme and terpenoid biosynthesis were associated with decreased risks of physician-diagnosed inhalant allergy and asthma (OR range, 0.89-0.86; 95% CI range, 0.80-0.99 to 0.73-1.02). No associations of stool microbiota with lung function were observed. CONCLUSIONS: The diversity, relative abundance and functional pathways of stool microbiota were most consistently associated with physician-diagnosed inhalant allergy in school-age children and less consistently with other atopic diseases.

Impact of a clinical decision rule on antibiotic prescription for children with suspected lower respiratory tract infections presenting to European emergency departments: a simulation study based on routine data.

BACKGROUND: Discriminating viral from bacterial lower respiratory tract infections (LRTIs) in children is challenging thus commonly resulting in antibiotic overuse. The Feverkidstool, a validated clinical decision rule including clinical symptoms and C-reactive protein, safely reduced antibiotic use in children at low/intermediate risk for bacterial LRTIs in a multicentre trial at emergency departments (EDs) in the Netherlands. OBJECTIVES: Using routine data from an observational study, we simulated the impact of the Feverkidstool on antibiotic prescriptions compared with observed antibiotic prescriptions in children with suspected LRTIs at 12 EDs in eight European countries. METHODS: We selected febrile children aged 1 month to 5 years with respiratory symptoms and excluded upper respiratory tract infections. Using the Feverkidstool, we calculated individual risks for bacterial LRTI retrospectively. We simulated antibiotic prescription rates under different scenarios: (1) applying effect estimates on antibiotic prescription from the trial; and (2) varying both usage (50%-100%) and compliance (70%-100%) with the Feverkidstool's advice to withhold antibiotics in children at low/intermediate risk for bacterial LRTI (≤10%). RESULTS: Of 4938 children, 4209 (85.2%) were at low/intermediate risk for bacterial LRTI. Applying effect estimates from the trial, the Feverkidstool reduced antibiotic prescription from 33.5% to 24.1% [pooled risk difference: 9.4% (95% CI: 5.7%-13.1%)]. Simulating 50%-100% usage with 90% compliance resulted in risk differences ranging from 8.3% to 15.8%. Our simulations suggest that antibiotic prescriptions would be reduced in EDs with high baseline antibiotic prescription rates or predominantly (>85%) low/intermediate-risk children. CONCLUSIONS: Implementation of the Feverkidstool could reduce antibiotic prescriptions in children with suspected LRTIs in European EDs.

Association between nasal and nasopharyngeal bacterial colonization in early life and eczema phenotypes.

BACKGROUND: An association has been reported between early life Staphylococcus aureus nasal carriage and higher risk of childhood eczema, but it is unclear whether this relationship is causal and associations with other bacterial species are unclear. OBJECTIVE: To examine the associations of early life nasal and nasopharyngeal bacterial carriage with eczema phenotypes, and the direction of any associations identified. METHODS: Among 996 subjects of a population-based prospective cohort study, nasal swabs for Staphylococcus  aureus, and nasopharyngeal swabs for Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae were collected and cultured from age 6 weeks to 6 years. Never, early, mid-, late transient and persistent eczema phenotypes were identified from parental-reported physician-diagnosed eczema from age 6 months until 10 years. Multinomial regression models and cross-lagged models were applied. RESULTS: Staphylococcus aureus nasal carriage at 6 months was associated with an increased risk of early transient and persistent eczema (OR (95% CI): 2.69 (1.34, 5.39) and 4.17 (1.12, 15.51)). The associations between Staphylococcus aureus nasal carriage and eczema were mostly cross-sectional, and not longitudinal. No associations of Staphylococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenza nasopharyngeal bacterial carriage with eczema and eczema phenotypes were observed (OR range (95% CI): 0.71 (0.35, 1.44) to 1.77 (0.84, 3.73)). CONCLUSIONS: Early life Staphylococcus aureus nasal carriage, but not Staphylococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenza nasopharyngeal carriage, was associated with early transient and persistent eczema. Staphylococcus aureus nasal carriage and eczema were mostly cross-sectionally associated, and not longitudinally, making a causal relationship in either direction unlikely.

Increased Th22 cell numbers in a general pediatric population with filaggrin haploinsufficiency: The Generation R Study.

BACKGROUND: Mutations in the filaggrin gene (FLG) affect epidermal barrier function and increase the risk of atopic dermatitis (AD). We hypothesized that FLG mutations affect immune cell composition in a general pediatric population. Therefore, we investigated whether school-aged children with and without FLG mutations have differences in T- and B-cell subsets. METHODS: This study was embedded in a population-based prospective cohort study, the Generation R Study, and included 523 children of European genetic ancestry aged 10 years. The most common FLG mutations in the European population (R501X, S1085CfsX36, R2447X, and S3247X) were genotyped. Additionally, 11-color flow cytometry was performed on peripheral blood samples to determine helper T (Th), regulatory T (Treg), and CD27+ and CD27- memory B cells. Subset analysis was performed in 358 non-AD and 102 AD cases, assessed by parental questionnaires. RESULTS: FLG mutations were observed in 8.4% of the total population and in 15.7% of the AD cases. Children with any FLG mutation had higher Th22 cell numbers compared to FLG wild-type children in the general and non-AD population. Children with and without FLG mutations had no difference in Th1, Th2, Th17, Treg, or memory B-cell numbers. Furthermore, in children with AD, FLG mutation carriership was not associated with differences in T- and B-cell subsets. CONCLUSIONS: School-aged children of a general population with FLG mutations have higher Th22 cell numbers, which reflects the immunological response to the skin barrier dysfunction. FLG mutations did not otherwise affect the composition of the adaptive immunity in this general pediatric population.

T cell composition and polygenic multiple sclerosis risk: A population-based study in children.

BACKGROUND AND PURPOSE: Patients with multiple sclerosis (MS) have altered T cell function and composition. Common genetic risk variants for MS affect proteins that function in the immune system. It is currently unclear to what extent T cell composition is affected by genetic risk factors for MS, and how this may precede a possible disease onset. Here, we aim to assess whether an MS polygenic risk score (PRS) is associated with an altered T cell composition in a large cohort of children from the general population. METHODS: We included genotyped participants from the population-based Generation R study in whom immunophenotyping of blood T cells was performed at the age of 6 years. Analyses of variance were used to determine the impact of MS-PRSs on total T cell numbers (n = 1261), CD4+ and CD8+ lineages, and subsets therein (n= 675). In addition, T-cell-specific PRSs were constructed based on functional pathway data. RESULTS: The MS-PRS negatively correlated with CD8+ T cell frequencies (p = 2.92 × 10-3 ), which resulted in a positive association with CD4+ /CD8+ T cell ratios (p = 8.27 × 10-9 ). These associations were mainly driven by two of 195 genome-wide significant MS risk variants: the main genetic risk variant for MS, HLA-DRB1*15:01 and an HLA-B risk variant. We observed no significant associations for the T-cell-specific PRSs. CONCLUSIONS: Our results suggest that MS-associated genetic variants affect T cell composition during childhood in the general population.

The role of food selectivity in the association between child autistic traits and constipation.

OBJECTIVE: This study examines the association between child autistic traits and constipation symptoms, and explores whether this association is mediated by food selectivity. METHOD: The sample included participants (N = 2,818) from the population-based birth cohort, Generation R (Rotterdam, the Netherlands). Parents reported their child's autistic traits at 6 years (using the Social Responsiveness Scale), food selectivity at 10 years (using the Stanford Feeding Questionnaire) and the frequency and severity of constipation symptoms they experienced at 10 years (using the ROME III functional constipation diagnostic criteria). Mediation analyses tested mediation through food selectivity in the association of autistic traits and the number of constipation symptoms, adjusting for covariates. RESULTS: There was a positive association between parent-reported child autistic traits and constipation symptoms (r = 0.08, p < .001). We identified a significant indirect effect of autistic traits on constipation symptoms through food selectivity (ß = 0.008, 95% Confidence Interval: 0.002, 0.014). DISCUSSION: This study provides empirical support for the mediating role of food selectivity in the association between autistic traits and constipation. Behavioral interventions aimed to target food selectivity and support families of children with autistic traits may bolster conventional medical and nutritional treatments to alleviate gastrointestinal symptoms like constipation.

The influence of chest X-ray results on antibiotic prescription for childhood pneumonia in the emergency department.

The aim of this study is to evaluate the influence of chest X-ray (CXR) results on antibiotic prescription in children suspected of lower respiratory tract infections (RTI) in the emergency department (ED). We performed a secondary analysis of a stepped-wedge, cluster randomized trial of children aged 1 month to 5 years with fever and cough/dyspnoea in 8 EDs in the Netherlands (2016-2018), including a 1-week follow-up. We analysed the observational data of the pre-intervention period, using multivariable logistic regression to evaluate the influence of CXR result on antibiotic prescription. We included 597 children (median age 17 months [IQR 9-30, 61% male). CXR was performed in 109/597 (18%) of children (range across hospitals 9 to 50%); 52/109 (48%) showed focal infiltrates. Children who underwent CXR were more likely to receive antibiotics, also when adjusted for clinical signs and symptoms, hospital and CXR result (OR 7.25 [95% CI 2.48-21.2]). Abnormalities on CXR were not significantly associated with antibiotic prescription.Conclusion: Performance of CXR was independently associated with more antibiotic prescription, regardless of its results. The limited influence of CXR results on antibiotic prescription highlights the inferior role of CXR on treatment decisions for suspected lower RTI in the ED. What is Known: • Chest X-ray (CXR) has a high inter-observer variability and cannot distinguish between bacterial or viral pneumonia. • Current guidelines recommend against routine use of CXR in children with uncomplicated respiratory tract infections (RTIs) in the outpatient setting. What is New: • CXR is still frequently performed in non-complex children suspected of lower RTIs in the emergency department • CXR performance was independently associated with more antibiotic prescriptions, regardless of its results, highlighting the inferior role of chest X-rays in treatment decisions.