Fibrin-targeting immunotherapy protects against neuroinflammation and neurodegeneration.

Activation of innate immunity and deposition of blood-derived fibrin in the central nervous system (CNS) occur in autoimmune and neurodegenerative diseases, including multiple sclerosis (MS) and Alzheimer's disease (AD). However, the mechanisms that link disruption of the blood-brain barrier (BBB) to neurodegeneration are poorly understood, and exploration of fibrin as a therapeutic target has been limited by its beneficial clotting functions. Here we report the generation of monoclonal antibody 5B8, targeted against the cryptic fibrin epitope γ377-395, to selectively inhibit fibrin-induced inflammation and oxidative stress without interfering with clotting. 5B8 suppressed fibrin-induced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and the expression of proinflammatory genes. In animal models of MS and AD, 5B8 entered the CNS and bound to parenchymal fibrin, and its therapeutic administration reduced the activation of innate immunity and neurodegeneration. Thus, fibrin-targeting immunotherapy inhibited autoimmunity- and amyloid-driven neurotoxicity and might have clinical benefit without globally suppressing innate immunity or interfering with coagulation in diverse neurological diseases.

Household Transmission Dynamics of Asymptomatic SARS-CoV-2-Infected Children: A Multinational, Controlled Case-Ascertained Prospective Study.

BACKGROUND: Asymptomatic SARS-CoV-2 infection in children is highly prevalent but its acute and chronic implications have been minimally described. METHODS: In this controlled case-ascertained household transmission study, we recruited asymptomatic children <18 years with SARS-CoV-2 nucleic acid testing performed at 12 tertiary care pediatric institutions in Canada and the United States. We attempted to recruit all test-positive children and 1 to 3 test-negative, site-matched controls. After 14 days' follow-up we assessed the clinical (ie, symptomatic) and combined (ie, test-positive, or symptomatic) secondary attack rates (SARs) among household contacts. Additionally, post-COVID-19 condition (PCC) was assessed in SARS-CoV-2-positive participating children after 90 days' follow-up. RESULTS: A total of 111 test-positive and 256 SARS-CoV-2 test-negative asymptomatic children were enrolled between January 2021 and April 2022. After 14 days, excluding households with co-primary cases, the clinical SAR among household contacts of SARS-CoV-2-positive and -negative index children was 10.6% (19/179; 95% CI: 6.5%-16.1%) and 2.0% (13/663; 95% CI: 1.0%-3.3%), respectively (relative risk = 5.4; 95% CI: 2.7-10.7). In households with a SARS-CoV-2-positive index child, age <5 years, being pre-symptomatic (ie, developed symptoms after test), and testing positive during Omicron and Delta circulation periods (vs earlier) were associated with increased clinical and combined SARs among household contacts. Among 77 asymptomatic SARS-CoV-2-infected children with 90-day follow-up, 6 (7.8%; 95% CI: 2.9%-16.2%) reported PCC. CONCLUSIONS: Asymptomatic SARS-CoV-2-infected children, especially those <5 years, are important contributors to household transmission, with 1 in 10 exposed household contacts developing symptomatic illness within 14 days. Asymptomatic SARS-CoV-2-infected children may develop PCC.

Remote electrical neuromodulation to treat children and adolescents with migraine in the emergency department: A randomized double-dummy pilot trial.

OBJECTIVE: Using a double-dummy pilot randomized controlled trial design, we aimed to determine the feasibility and acceptability of comparing remote electrical neuromodulation (REN) to typical care intravenous pharmacologic interventions for the treatment of children and adolescents visiting the emergency department (ED) with migraine, and to compare parallel-group versus crossover trial designs. BACKGROUND: There are limited data to guide the management of migraine in the ED. Children and adolescents are interested in neuromodulation, and specifically REN, for treatment in this setting, but there are no existing data on this approach. METHODS: We employed a double-dummy, double-blind, pilot randomized controlled trial that tested two designs in two phases: a parallel-group design and a crossover design (ClinicalTrials.gov identifier: NCT05102591). The intervention arms consisted of: (i) active REN stimulation with matched normal saline placebo intravenously, and (ii) matched sham REN stimulation, intravenous metoclopramide (0.15 mg/kg, maximum 10 mg), and intravenous ketorolac (0.5 mg/kg, maximum 30 mg). Youth aged 8.0-<18.0 years visiting a Canadian tertiary care pediatric ED with migraine attacks as per criteria B-E of the International Classification of Headache Disorders third edition were eligible. Primary outcomes were focused on trial feasibility and acceptability, and preliminary efficacy and safety data were also collected. RESULTS: A total of 34% (22/65) of those who screened eligible were enrolled. Three participants (14%) withdrew prior to receiving any study interventions. In all, 10 participants were allocated to typical care, and nine to REN. All treated participants (19/19) completed all assessments. Recruitment was higher during the parallel-group phase: 1.1 participants/month versus 0.6 participants/month, and 36% (17/47) versus 28% (five of 18) of screened eligible were enrolled in the parallel-group and crossover phases, respectively. Participants reported positive impressions of REN use in the ED, e.g., higher mean (standard deviation [SD]) levels of interest in using REN only at 3.7 (1.0) versus 2.8 (1.0) in using intravenous interventions only for a future ED visit. Participants and clinical staff reported overall positive impressions regarding the study protocol. Employing an 11-point pain numerical rating scale, the mean (SD) reduction in pain severity score was 2.1 (1.3) and 2.9 (2.9) from baseline to 1 h, and 2.4 (1.6) and 4.0 (3.5) from baseline to 2 h for REN and intravenous interventions, respectively. One participant in the typical care group and none in the REN group experienced adverse events. CONCLUSION: We demonstrated the feasibility and acceptability of our trial protocol and of using REN to treat youth presenting to the ED with migraine. The parallel-group design generated a higher recruitment rate than the crossover design. Our preliminary efficacy and safety data suggest that REN could be non-inferior to typical care, but we were not powered for these outcomes. Further research on REN's use in the ED setting is warranted.

Do preinjury life events moderate the outcomes of mild traumatic brain injuries in children? An A-CAP Study.

OBJECTIVE: To examine preinjury life events as moderators of postconcussive symptoms (PCS) and quality of life (QoL) in children with pediatric mild traumatic brain injury (mTBI) versus orthopedic injury (OI). METHODS: Participants were 633 children with mTBI and 334 with OI, ages 8-16.99, recruited from 5 pediatric emergency departments and followed for 6 months postinjury as part of a prospective cohort study. Preinjury life events were measured retrospectively using the Child and Adolescent Survey of Experiences, PCS using the Health and Behavior Inventory (HBI) and Post-Concussion Symptom Interview (PCS-I), and QoL using the Pediatric Quality of Life Inventory (PedsQL). Analyses involved longitudinal regression using restricted cubic splines, with group, positive and negative life events, and time as primary predictors. Covariates included age, sex, race, socioeconomic status, preinjury history (i.e., headache, migraine, previous concussion), and parent-rated retrospective PCS-I, HBI, and PedsQL scores. RESULTS: PCS and QoL were worse after mTBI than OI, but group differences declined with time (all p < .001). Group differences in PCS were larger at higher levels of positive life events, which predicted lower PCS (p= .03 to p < .001) and higher QoL (p = .048) after OI but not after mTBI. Negative life events predicted worse PCS and QoL in both groups (p = .002 to p < .001). CONCLUSIONS: Preinjury positive life events moderate outcomes after pediatric injury, with a protective effect seen in OI but not in mTBI. Negative life events are consistently associated with worse outcomes regardless of injury type.

Molecular epidemiology of rotavirus among children in Western Canada: Dynamic changes in genotype prevalence in four consecutive seasons.

Rotavirus molecular surveillance remains important in the postvaccine era to monitor the changes in transmission patterns, identify vaccine-induced antigenic changes and discover potentially pathogenic vaccine-related strains. The Canadian province of Alberta introduced rotavirus vaccination into its provincial vaccination schedule in June 2015. To evaluate the impact of this program on stool rotavirus positivity rate, strain diversity, and seasonal trends, we analyzed a prospective cohort of children with acute gastroenteritis recruited between December 2014 and August 2018. We identified dynamic changes in rotavirus positivity and genotype trends during pre- and post-rotavirus vaccine introduction periods. Genotypes G9P[8], G1P[8], G2P[4], and G12P[8] predominated consecutively each season with overall lower rotavirus incidence rates in 2016 and 2017. The demographic and clinical features of rotavirus gastroenteritis were comparable among wild-type rotaviruses; however, children with G12P[8] infections were older (p < 0.001). Continued efforts to monitor changes in the molecular epidemiology of rotavirus using whole genome sequence characterization are needed to further understand the impact of the selection pressure of vaccination on rotavirus evolution.

Emergency department visits and hospital admissions for suicidal ideation, self-poisoning and self-harm among adolescents in Canada during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic had profound effects on the mental wellbeing of adolescents. We sought to evaluate pandemic-related changes in health care use for suicidal ideation, self-poisoning and self-harm. METHODS: We obtained data from the Canadian Institute for Health Information on emergency department visits and hospital admissions from April 2015 to March 2022 among adolescents aged 10-18 years in Canada. We calculated the quarterly percentage of emergency department visits and hospital admissions for a composite outcome comprising suicidal ideation, self-poisoning and self-harm relative to all-cause emergency department visits and hospital admissions. We used interrupted time-series methods to compare changes in levels and trends of these outcomes between the prepandemic (Apr. 1, 2015-Mar. 1, 2020) and pandemic (Apr. 1, 2020-Mar. 31, 2022) periods. RESULTS: The average quarterly percentage of emergency department visits for suicidal ideation, self-poisoning and self-harm relative to all-cause emergency department visits was 2.30% during the prepandemic period and 3.52% during the pandemic period. The level (0.08%, 95% confidence interval [CI] -0.79% to 0.95%) or trend (0.07% per quarter, 95% CI -0.14% to 0.28%) of this percentage did not change significantly between periods. The average quarterly percentage of hospital admissions for the composite outcome relative to all-cause admissions was 7.18% during the prepandemic period and 8.96% during the pandemic period. This percentage showed no significant change in level (-0.70%, 95% CI -1.90% to 0.50%), but did show a significantly increasing trend (0.36% per quarter; 95% 0.07% to 0.65%) during the pandemic versus prepandemic periods, specifically among females aged 10-14 years (0.76% per quarter, 95% CI 0.22% to 1.30%) and females aged 15-18 years (0.56% per quarter, 95% CI 0.31% to 0.81%). INTERPRETATION: The quarterly change in the percentage of hospital admissions for suicidal ideation, self-poisoning and self-harm increased among adolescent females in Canada during the first 2 years of the COVID-19 pandemic. This underscores the need to promote public health policies that mitigate the impact of the pandemic on adolescent mental health.

Characterizing the Pain Experience of Children With Acute Gastroenteritis Based on Identified Pathogens.

OBJECTIVES: Pain is common with acute gastroenteritis (AGE) yet little is known about the severity associated with specific enteropathogens. We sought to explore the correlation of pain severity with specific enteropathogens in children with AGE. METHODS: Participants were prospectively recruited by the Alberta Provincial Pediatric EnTeric Infection TEam at 2 pediatric emergency departments (EDs) (December 2014-August 2018). Pain was measured (by child and/or caregiver) using the 11-point Verbal Numerical Rating Scale. RESULTS: We recruited 2686 participants; 46.8% (n = 1256) females, with median age 20.1 months (interquartile range 10.3, 45.3). The mean highest pain scores were 5.5 [standard deviation (SD) 3.0] and 4.2 (SD 2.9) in the 24 hours preceding the ED visit, and in the ED, respectively. Prior to ED visit, the mean highest pain scores with bacterial detection were 6.6 (SD 2.5), compared to 5.5 (SD 2.9) for single virus and 5.5 (SD 3.1) for negative stool tests. In the ED, the mean highest pain scores with bacterial detection were 5.5 (SD 2.7), compared to 4.1 (SD 2.9) for single virus and 4.2 (SD 3.0) for negative stool tests. Using multivariable modeling, factors associated with greater pain severity prior to ED visit included older age, fever, illness duration, number of diarrheal or vomiting episodes in the preceding 24 hours, and respiratory symptoms, but not enteropathogen type. CONCLUSION: Children with AGE experience significant pain, particularly when the episode is associated with the presence of a bacterial enteric pathogen. However, older age and fever appear to influence children's pain experiences more than etiologic pathogens.

Visits to Alberta Emergency Departments for Child Mental Health Concerns During the COVID-19 Pandemic: An Examination of Visit Trends in Relation to School Closures and Reopenings.

OBJECTIVE: We examined emergency department (ED) mental health visit trends by children in relation to periods of school closure and reopening during the COVID-19 pandemic in Alberta, Canada. METHODS: Mental health visits by school-aged children (5 to <18 years) were extracted from the Emergency Department Information System, a province-wide database, from March 11, 2020, to November 30, 2021 (pandemic period; n = 18,997) and March 1, 2019, to March 10, 2020 (1-year, prepandemic comparator period; n = 11,540). We calculated age-specific visit rates and compared rate differences between periods of school closure (March 15-June 30, 2020; November 30, 2020-January 10, 2021; April 22-June 30, 2021) and reopening (September 4-November 29, 2020; January 11-April 21, 2021; September 3-November 30, 2021) to matched prepandemic periods. We used a ratio of relative risk to examine the risk of a visit during closures versus reopenings. RESULTS: The cohort included 11,540 prepandemic visits and 18,997 pandemic visits. Compared with prepandemic periods, ED visit rates increased across all ages during the first (+85.53%; 95% confidence interval [CI], 73.68% to 100.41%) and third (+19.92%; 95% CI, 13.28% to 26.95%) school closures, and decreased during the second closure (-15.37%; 95% CI, -22.22% to -7.92%). During school reopenings, visit rates decreased across all ages during the first reopening (-9.30%; 95% CI, -13.94% to -4.41%) and increased during the third reopening (+13.59%; 95% CI, 8.13% to 19.34%); rates did not change significantly during the second reopening (2.54%; 95% CI, -3.45% to 8.90%). The risk of a visit during school closure versus reopening was only higher for the first closure with 2.06 times the risk (95% CI, 1.88 to 2.25). CONCLUSIONS: Emergency department mental health visit rates were highest during the first school closure of the COVID-19 pandemic, and the risk of a visit during this closure period was twice compared with when schools first reopened.

Clinical Profiles of Childhood Astrovirus-, Sapovirus-, and Norovirus-Associated Acute Gastroenteritis in Pediatric Emergency Departments in Alberta, 2014-2018.

BACKGROUND: Infections by previously underdiagnosed viruses astrovirus and sapovirus are poorly characterized compared with norovirus, the most common cause of acute gastroenteritis. METHODS: Children <18 years old with acute gastroenteritis were recruited from pediatric emergency departments in Alberta, Canada between 2014 and 2018. We described and compared the clinical course of acute gastroenteritis in children with astrovirus, sapovirus, and norovirus. RESULTS: Astrovirus was detected in 56 of 2688 (2.1%) children, sapovirus was detected in 146 of 2688 (5.4%) children, and norovirus was detected in 486 of 2688 (18.1%) children. At illness onset, ~60% of astrovirus cases experienced both diarrhea and vomiting. Among sapovirus and norovirus cases, 35% experienced diarrhea at onset and 80% of 91% (sapovirus/norovirus) vomited; however, diarrhea became more prevalent than vomiting at approximately day 4 of illness. Over the full course of illness, diarrhea was 18% (95% confidence interval [CI], 8%- 29%) more prevalent among children with astrovirus than norovirus infections and had longer duration with greater maximal events; there were a median of 4.0 fewer maximal vomiting events (95% CI, 2.0-5.0). Vomiting continued for a median of 24.8 hours longer (95% CI, 9.6-31.7) among children with sapovirus versus norovirus. Differences between these viruses were otherwise minimal. CONCLUSIONS: Sapovirus infections attended in the emergency department are more similar to norovirus than previously reported, whereas astrovirus infections have several distinguishable characteristics.

Pathogen-Specific Effects of Probiotics in Children With Acute Gastroenteritis Seeking Emergency Care: A Randomized Trial.

BACKGROUND: It is unknown if probiotics exert pathogen-specific effects in children with diarrhea secondary to acute gastroenteritis. METHODS: Analysis of patient-level data from 2 multicenter randomized, placebo controlled trials conducted in pediatric emergency departments in Canada and the United States. Participants were 3-48 months with >3 diarrheal episodes in the preceding 24 hours and were symptomatic for <72 hours and <7 days in the Canadian and US studies, respectively. Participants received either placebo or a probiotic preparation (Canada-Lactobacillus rhamnosus R0011/Lactobacillus helveticus R0052; US-L. rhamnosus GG). The primary outcome was post-intervention moderate-to-severe disease (ie, ≥9 on the Modified Vesikari Scale [MVS] score). RESULTS: Pathogens were identified in specimens from 59.3% of children (928/1565). No pathogen groups were less likely to experience an MVS score ≥9 based on treatment allocation (test for interaction = 0.35). No differences between groups were identified for adenovirus (adjusted relative risk [aRR]: 1.42; 95% confidence interval [CI]: .62, 3.23), norovirus (aRR: 0.98; 95% CI: .56, 1.74), rotavirus (aRR: 0.86; 95% CI: .43, 1.71) or bacteria (aRR: 1.19; 95% CI: .41, 3.43). At pathogen-group and among individual pathogens there were no differences in diarrhea duration or the total number of diarrheal stools between treatment groups, regardless of intervention allocation or among probiotic sub-groups. Among adenovirus-infected children, those administered the L. rhamnosus R0011/L. helveticus R0052 product experienced fewer diarrheal episodes (aRR: 0.65; 95% CI: .47, .90). CONCLUSIONS: Neither probiotic product resulted in less severe disease compared to placebo across a range of the most common etiologic pathogens. The preponderance of evidence does not support the notion that there are pathogen specific benefits associated with probiotic use in children with acute gastroenteritis. CLINICAL TRIALS REGISTRATION: NCT01773967 and NCT01853124.

Structural connectome differences in pediatric mild traumatic brain and orthopedic injury.

Sophisticated network-based approaches such as structural connectomics may help to detect a biomarker of mild traumatic brain injury (mTBI) in children. This study compared the structural connectome of children with mTBI or mild orthopedic injury (OI) to that of typically developing (TD) children. Children aged 8-16.99 years with mTBI (n = 83) or OI (n = 37) were recruited from the emergency department and completed 3T diffusion MRI 2-20 days postinjury. TD children (n = 39) were recruited from the community and completed diffusion MRI. Graph theory metrics were calculated for the binarized average fractional anisotropy among 90 regions. Multivariable linear regression and linear mixed effects models were used to compare groups, with covariates age, hemisphere, and sex, correcting for multiple comparisons. The two injury groups did not differ on graph theory metrics, but both differed from TD children in global metrics (local network efficiency: TD > OI, mTBI, d = 0.49; clustering coefficient: TD < OI, mTBI, d = 0.49) and regional metrics for the fusiform gyrus (lower degree centrality and nodal efficiency: TD > OI, mTBI, d = 0.80 to 0.96; characteristic path length: TD < OI, mTBI, d = -0.75 to -0.90) and in the superior and middle orbital frontal gyrus, paracentral lobule, insula, and thalamus (clustering coefficient: TD > OI, mTBI, d = 0.66 to 0.68). Both mTBI and OI demonstrated reduced global and regional network efficiency and segregation as compared to TD children. Findings suggest a general effect of childhood injury that could reflect pre- and postinjury factors that can alter brain structure. An OI group provides a more conservative comparison group than TD children for structural neuroimaging research in pediatric mTBI.

Longitudinal white matter microstructural changes in pediatric mild traumatic brain injury: An A-CAP study.

In the largest sample studied to date, white matter microstructural trajectories and their relation to persistent symptoms were examined after pediatric mild traumatic brain injury (mTBI). This prospective, longitudinal cohort study recruited children aged 8-16.99 years with mTBI or mild orthopedic injury (OI) from five pediatric emergency departments. Children's pre-injury and 1-month post-injury symptom ratings were used to classify mTBI with or without persistent symptoms. Children completed diffusion-weighted imaging at post-acute (2-33 days post-injury) and chronic (3 or 6 months via random assignment) post-injury assessments. Mean diffusivity (MD) and fractional anisotropy (FA) were derived for 18 white matter tracts in 560 children (362 mTBI/198 OI), 407 with longitudinal data. Superior longitudinal fasciculus FA was higher in mTBI without persistent symptoms relative to OI, d (95% confidence interval) = 0.31 to 0.37 (0.02, 0.68), across time. In younger children, MD of the anterior thalamic radiations was higher in mTBI with persistent symptoms relative to both mTBI without persistent symptoms, 1.43 (0.59, 2.27), and OI, 1.94 (1.07, 2.81). MD of the arcuate fasciculus, -0.58 (-1.04, -0.11), and superior longitudinal fasciculus, -0.49 (-0.90, -0.09) was lower in mTBI without persistent symptoms relative to OI at 6 months post-injury. White matter microstructural changes suggesting neuroinflammation and axonal swelling occurred chronically and continued 6 months post injury in children with mTBI, especially in younger children with persistent symptoms, relative to OI. White matter microstructure appears more organized in children without persistent symptoms, consistent with their better clinical outcomes.

Why antibiotics should not be used to treat Shiga toxin-producing Escherichia coli infections.

PURPOSE OF REVIEW: There has been much debate about treating Shiga toxin-producing Escherichia coli (STEC) infections with antibiotics. No data convincingly demonstrate that antibiotics are better than no antibiotic treatment at all, and many studies suggest antibiotics increase the risk of developing the hemolytic uremic syndrome (HUS). This topic is timely, because emerging technology enables rapid identification of STEC-infected patients, and we anticipate questions about management will increase. This review is designed to familiarize readers with the series of observations that underlie our recommendations. RECENT FINDINGS: The long debate over antibiotics in STEC infections appears resolved by gradually accruing information that show that antibiotics do not benefit infected patients. In fact, they are associated with an increased likelihood of developing HUS. A meta-analysis published in 2016 demonstrated that low risk of bias studies find a clear association between antibiotic use and development of HUS. Subsequent publications do not refute these findings. SUMMARY: In high-income countries, antibiotics should not routinely be given to patients with acute diarrhea unless testing demonstrates a pathogen for which antibiotics are indicated, and STEC infection has been excluded. Future work to prevent HUS should focus on preventing primary infections, and mitigating extraintestinal consequences of STEC gut infections.

Oral Ondansetron Administration in Children Seeking Emergency Department Care for Acute Gastroenteritis: A Patient-Level Propensity-Matched Analysis.

STUDY OBJECTIVE: This study aimed to explore oral ondansetron usage and impact on outcomes in clinical practice. METHODS: This observational study was a planned secondary analysis of 2 trials conducted in 10 US and 6 Canadian institutions between 2014 and 2017. Children 3 to 48 months old with gastroenteritis and ≥3 episodes of vomiting in the 24 hours preceding emergency department (ED) presentation were included. Oral ondansetron was administered at the discretion of the provider. The principal outcomes were intravenous fluid administration and hospitalization at the index visit and during the subsequent 72 hours and diarrhea and vomiting frequency during the 24 hours following the ED visit. RESULTS: In total, 794 children were included. The median age was 16.0 months (interquartile range 10.0 to 26.0), and 50.1% (398/794) received oral ondansetron. In propensity-adjusted analysis (n=528), children administered oral ondansetron were less likely to receive intravenous fluids at the index visit (adjusted odds ratio [aOR] 0.50; 95% confidence interval [CI] 0.29 to 0.88). There were no differences in the frequencies of intravenous fluid administration within the first 72 hours (aOR 0.65; 95% CI 0.39 to 1.10) or hospitalization at the index visit (aOR 0.31; 95% CI 0.09 to 1.10) or the subsequent 72 hours (aOR 0.52; 95% CI 0.21 to 1.28). Episodes of vomiting (aRR 0.86; 95% CI 0.63 to 1.19) and diarrhea (aRR 1.11; 95% CI 0.93 to 1.32) during the 24 hours following ED discharge also did not differ. CONCLUSION: Among preschool-aged children with gastroenteritis seeking ED care, oral ondansetron administration was associated with a reduction in index ED visit intravenous fluid administration; it was not associated with intravenous fluids administered within 72 hours, hospitalization, or vomiting and diarrhea in the 24 hours following discharge.

Derivation of the Pediatric Acute Gastroenteritis Risk Score to Predict Moderate-to-Severe Acute Gastroenteritis.

OBJECTIVES: Although most acute gastroenteritis (AGE) episodes in children rapidly self-resolve, some children go on to experience more significant and prolonged illness. We sought to develop a prognostic score to identify children at risk of experiencing moderate-to-severe disease after an index emergency department (ED) visit. METHODS: Data were collected from a cohort of children 3 to 48 months of age diagnosed with AGE in 16 North American pediatric EDs. Moderate-to-severe AGE was defined as a Modified Vesikari Scale (MVS) score ≥9 during the 14-day post-ED visit. A clinical prognostic model was derived using multivariable logistic regression and converted into a simple risk score. The model's accuracy was assessed for moderate-to-severe AGE and several secondary outcomes. RESULTS: After their index ED visit, 19% (336/1770) of participants developed moderate-to-severe AGE. Patient age, number of vomiting episodes, dehydration status, prior ED visits, and intravenous rehydration were associated with MVS ≥9 in multivariable regression. Calibration of the prognostic model was strong with a P value of 0.77 by the Hosmer-Lemenshow goodness-of-fit test, and discrimination was moderate with an area under the receiver operator characteristic curve of 0.68 (95% confidence interval [CI] 0.65-0.72). Similarly, the model was shown to have good calibration when fit to the secondary outcomes of subsequent ED revisit, intravenous rehydration, or hospitalization within 72 hours after the index visit. CONCLUSIONS: After external validation, this new risk score may provide clinicians with accurate prognostic insight into the likely disease course of children with AGE, informing disposition decisions, anticipatory guidance, and follow-up care.

Paediatric post-concussive symptoms: symptom clusters and clinical phenotypes.

OBJECTIVE: To assess the co-occurrence and clustering of post-concussive symptoms in children, and to identify distinct patient phenotypes based on symptom type and severity. METHODS: We performed a secondary analysis of the prospective, multicentre Predicting and Preventing Post-concussive Problems in Pediatrics (5P) cohort study, evaluating children 5-17 years of age presenting within 48 hours of an acute concussion. Our primary outcome was the simultaneous occurrence of two or more persistent post-concussive symptoms on the Post-Concussion Symptom Inventory at 28 days post-injury. Analyses of symptom and patient clusters were performed using hierarchical cluster analyses of symptom severity ratings. RESULTS: 3063 patients from the parent 5P study were included. Median age was 12.1 years (IQR: 9.2-14.6 years), and 1857 (60.6%) were male. Fatigue was the most common persistent symptom (21.7%), with headache the most commonly reported co-occurring symptom among patients with fatigue (55%; 363/662). Headache was common in children reporting any of the 12 other symptoms (range: 54%-72%). Physical symptoms occurred in two distinct clusters: vestibular-ocular and headache. Emotional and cognitive symptoms occurred together more frequently and with higher severity than physical symptoms. Fatigue was more strongly associated with cognitive and emotional symptoms than physical symptoms. We identified five patient groups (resolved/minimal, mild, moderate, severe and profound) based on symptom type and severity. CONCLUSION: Post-concussive symptoms in children occur in distinct clusters, facilitating the identification of distinct patient phenotypes based on symptom type and severity. Care of children post-concussion must be comprehensive, with systems designed to identify and treat distinct post-concussion phenotypes.

Attribution of Pediatric Acute Gastroenteritis Episodes and Emergency Department Visits to Norovirus Genogroups I and II.

BACKGROUND: Norovirus is a leading cause of acute gastroenteritis. With vaccines in development, population-based estimates of norovirus burden are needed to identify target populations, quantify potential benefits, and understand disease dynamics. METHODS: We estimated the attributable fraction (AF) for norovirus infections in children, defined as the proportion of children testing positive for norovirus whose gastroenteritis was attributable to norovirus. We calculated the standardized incidence and emergency department (ED) visit rates attributable to norovirus using provincial gastroenteritis visit administrative data. RESULTS: From 3731 gastroenteritis case patients and 2135 controls we determined that the AFs were 67.0% (95% confidence interval [CI], 31.5%-100%) and 91.6% (88.8%-94.4%) for norovirus genogroups I (GI) and II (GII), respectively. Norovirus GII AF varied by season but not age. We attributed 116 episodes (95% CI, 103-129) and 59 (51-67) ED visits per 10 000 child-years to norovirus GII across all ages, accounting for 20% and 18% of all medically attended gastroenteritis episodes and ED visits, respectively. CONCLUSIONS: In children, a large proportion of norovirus GII detections reflect causation, demonstrating significant potential for norovirus GII vaccines. Seasonal variation in the norovirus GII AF may have implications for understanding the role asymptomatic carriage plays in disease dynamics.

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.