Hybrid immunity after BNT162b2 Covid-19 vaccine administration in children aged 5 to 11 years.

BACKGROUND: The immune response to coronavirus disease 2019 (COVID-19) vaccination is stronger among adults with prior infection (hybrid immunity). It is important to understand if children demonstrate a similar response to better inform vaccination strategies. Our study investigated the humoral response after BNT162b2 COVID-19 vaccine doses in SARS-CoV-2 naïve and recovered children (5-11 years). METHODS: A multi-institutional, longitudinal, prospective cohort study was conducted. Children were enrolled in a case-ascertained antibody surveillance study in Ottawa, Ontario from September/2020-March/2021; at least one household member was severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) positive on RT-PCR. In November 2021, BNT162b2 COVID-19 vaccine was authorized for children aged 5-11 in Canada. Children enrolled in the surveillance study intending to receive two vaccine doses were invited to participate in this study from November 2021-April 2022. Main exposure was prior SARS-CoV-2 infection, defined by positive RT-PCR or SARS-CoV-2 anti-N IgG antibody presence. Primary outcome was spike IgG antibody levels measured following the first vaccine dose (2-3 weeks) and second vaccine dose (3-4 weeks). RESULTS: Of the 153 eligible children, 75 participants (median age 8.9 IQR (7.4, 10.2) years; 38 (50.7 %) female; 59 (78.7 %) Caucasian) had complete follow-up. Fifty-four (72 %) children had prior SARS-COV-2 infection. Spike IgG antibody levels are significantly higher in SARS-CoV-2 recovered participants after receiving the first dose (p < 0.001) and the second (p = 0.01) compared to infection naïve children. CONCLUSIONS AND RELEVANCE: SARS-CoV-2 recovered children (5-11 years) demonstrated higher antibody levels following first BNT162b2 vaccine dose compared with naïve children. Most reached antibody saturation two to three weeks after the first dose; a second dose didn't change the saturation level. A single vaccine dose in SARS-CoV-2 recovered children may be equivalent or superior to a 2-dose primary series in naïve children. Further research is needed on the durability and quality of a single vaccine dose in this population.

Closing the Loop: The Value of Outcome Letters for Prehospital Pediatric Care.

OBJECTIVES: Providing emergency care to acutely ill or injured children is stressful and requires a high level of training. Paramedics who provide prehospital care are typically not involved in the circle of care and do not receive patient outcome information. The aim of this quality improvement project was to assess paramedics' perceptions of standardized outcome letters pertaining to acute pediatric patients that they had treated and transported to an emergency department. METHODS: Between December 2019 and December 2020, 888 outcome letters were distributed to paramedics who provided care for 370 acute pediatric patients transported to the Children's Hospital of Eastern Ontario in Ottawa, Canada. All paramedics who received a letter (n = 470) were invited to participate in a survey that collected their perceptions and feedback about the letters, as well as their demographic information. RESULTS: The response rate was 37% (172/470). Approximately half of the respondents were Primary Care Paramedics and half Advanced Care Paramedics. The respondents' median age was 36 years, median years of service was 12 years, and 64% identified as male. Most agreed that the outcome letters contained information pertinent to their practice (91%), allowed them to reflect on care they had provided (87%), and confirmed clinical suspicions (93%). Respondents indicated that they found the letters useful for 3 reasons: 1) increases capacity to link differential diagnoses, prehospital care, or patient outcomes; 2) contributes to a culture of continuous learning and improvement; and 3) gives closure, reduces stress, or provides answers for difficult cases. Suggestions for improvement included providing more information, provision of letters on all patients transported, faster turnaround time between call and receipt of letter and inclusion of recommendations or interventions/assessments. CONCLUSIONS: Paramedics appreciated receiving hospital-based patient outcome information after their provision of care and reported that the letters offered opportunities for closure, reflection, and learning.

Antibody Seronegativity in COVID-19 RT-PCR-Positive Children.

This substudy of a prospective case-ascertained household transmission study investigated severe acute respiratory syndrome coronavirus 2 reverse transcription polymerase chain reaction-positive individuals without antibody development and factors associated with nonseroconversion. Approximately 1 of 8 individuals with coronavirus disease 2019 did not seroconvert. Children, particularly the youngest, were approximately half as likely to seroconvert compared with adults. Apart from the absence of fever/chills, individual symptoms did not strongly predict nonseroconversion.

Household transmission of SARS-CoV-2 from unvaccinated asymptomatic and symptomatic household members with confirmed SARS-CoV-2 infection: an antibody-surveillance study.

BACKGROUND: Household transmission contributes to SARS-CoV-2 spread, but the role of children in transmission is unclear. We conducted a study that included symptomatic and asymptomatic children and adults exposed to SARS-CoV-2 in their households with the objective of determining how SARS-CoV-2 is transmitted within households. METHODS: In this case-ascertained antibody-surveillance study, we enrolled households in Ottawa, Ontario, in which at least 1 household member had tested positive for SARS-CoV-2 on reverse transcription polymerase chain reaction testing. The enrolment period was September 2020 to March 2021. Potentially eligible participants were identified if they had tested positive for SARS-CoV-2 at an academic emergency department or affiliated testing centre; people who learned about the study through the media could also self-identify for participation. At least 2 participants were required for a household to be eligible for study participation, and at least 1 enrolled participant per household had to be a child (age < 18 yr). Enzyme-linked immunosorbent assays were used to evaluate SARS-CoV-2-specific IgA, IgM and IgG against the spike-trimer and nucleocapsid protein. The primary outcome was household secondary attack rate, defined as the proportion of household contacts positive for SARS-CoV-2 antibody among the total number of household contacts participating in the study. We performed descriptive statistics at both the individual and household levels. To estimate and compare outcomes between patient subgroups, and to examine predictors of household transmission, we fitted a series of multivariable logistic regression with robust standard errors to account for clustering of individuals within households. RESULTS: We enrolled 695 participants from 180 households: 180 index participants (74 children, 106 adults) and 515 of their household contacts (266 children, 249 adults). A total of 487 household contacts (94.6%) (246 children, 241 adults) had SARS-CoV-2 antibody testing, of whom 239 had a positive result (secondary attack rate 49.1%, 95% confidence interval [CI] 42.9%-55.3%). Eighty-eight (36.8%, 95% CI 29.3%-43.2%) of the 239 were asymptomatic; asymptomatic rates were similar for children (51/130 [39.2%, 95% CI 30.7%-48.5%]) and adults (37/115 [32.2%, 95% CI 24.2%-41.4%]) (odds ratio [OR] 1.3, 95% CI 0.8-2.1). Adults were more likely than children to transmit SARS-CoV-2 (OR 2.2, 95% CI 1.3-3.6). The odds of transmission from asymptomatic (OR 0.6, 95% CI 0.2-1.4) versus symptomatic (OR 0.9, 95% CI 0.6-1.4) index participants to household contacts was uncertain. Predictors of household transmission included household density (number of people per bedroom), relationship to index participant and number of cases in the household. INTERPRETATION: The rate of SARS-CoV-2 transmission within households was nearly 50% during the study period, and children were an important source of spread. The findings suggest that children are an important driver of the COVID-19 pandemic; this should inform public health policy.

Is early activity resumption after paediatric concussion safe and does it reduce symptom burden at 2 weeks post injury? The Pediatric Concussion Assessment of Rest and Exertion (PedCARE) multicentre randomised clinical trial.

OBJECTIVE: Investigate whether resuming physical activity (PA) at 72 hours post concussion is safe and reduces symptoms at 2 weeks, compared with resting until asymptomatic. METHODS: Real-life conditions, multicentre, single-blinded randomised clinical trial, conducted in three Canadian paediatric emergency departments (ED). Children/youth aged 10-<18 years with acute concussion were recruited between March 2017 and December 2019, and randomly assigned to a 4-week stepwise return-to-PA protocol at 72 hours post concussion even if symptomatic (experimental group (EG)) or to a return-to-PA once asymptomatic protocol (control group (CG)). The primary outcome was self-reported symptoms at 2 weeks using the Health and Behaviour Inventory. Adherence was measured using accelerometers worn 24 hours/day for 14 days post injury. Adverse events (AE) (worsening of symptoms requiring unscheduled ED or primary care visit) were monitored. Multivariable intention-to-treat (ITT) and per-protocol analyses adjusting for prognostically important covariates were examined. Missing data were imputed for the ITT analysis. RESULTS: 456 randomised participants (EG: N=227; mean (SD) age=13.3 (2.1) years; 44.5% women; CG: N=229; mean (SD) age=13.3 (2.2) years; 43.7% women) were analysed. No AE were identified. ITT analysis showed no strong evidence of a group difference at 2 weeks (adjusted mean difference=-1.3 (95% CI:-3.6 to 1.1)). In adherent participants, initiating PA 72 hours post injury significantly reduced symptoms 2 weeks post injury, compared with rest (adjusted mean difference=-4.3 (95% CI:-8.4 to -0.2)). CONCLUSION: Symptoms at 2 weeks did not differ significantly between children/youth randomised to initiate PA 72 hours post injury versus resting until asymptomatic; however, many were non-adherent to the intervention. Among adherent participants, early PA was associated with reduced symptoms at 2 weeks. Resumption of PA is safe and may be associated with milder symptoms at 2 weeks. LEVEL OF EVIDENCE: 1b. TRIAL REGISTRATION NUMBER: NCT02893969. REGISTRY NAME: Pediatric Concussion Assessment of Rest and Exertion (PedCARE).

Symptom Burden, School Function, and Physical Activity One Year Following Pediatric Concussion.

OBJECTIVES: To characterize symptom burden, school function, and physical activity in youth 1 year following acute concussion and those with subsequent repeat concussion. STUDY DESIGN: Secondary analysis of Predicting Persistent Postconcussive Problems in Pediatrics prospective, multicenter cohort study conducted in 9 Canadian emergency departments. Participants were children between ages 5 and 18 years who presented consecutively ≤48 hours of concussion and agreed to participate in a post hoc electronic survey 1 year after injury. Outcomes were assessed using a standardized 25-question symptom scale derived from the Post-Concussion Symptom Inventory-Parent; school function and physical activity outcomes were queried. The primary outcome was total symptom score 1 year following concussion, defined as the number of symptoms experienced more than before injury. RESULTS: Of 3052 youth enrolled in the Predicting Persistent Postconcussive Problems in Pediatrics study, 432 (median [IQR] age, 11.5 [9,14] years; 266 [62%] male) completed the 1-year survey; 34 respondents reported a repeat concussion. Following acute concussion, youth were more likely to be symptom-free than following repeat concussion (75% vs 50%; difference = 25% [95% CI 8-41]; P = .002) and to have recovered fully (90% vs 74%; difference = 17% [95% CI 5-34]; P = .002) after 1 year. Although physical symptoms were less 1 year after initial emergency department presentation for both groups (P < .001), youth with a repeat concussion reported greater headache persistence (26% vs 13%; difference = 13% [95% CI 1,31]; P = .024). Both groups returned to their normal school routine (100% vs 95%; difference = 5% [95% CI -5 to 8; P = .618). Youth without repeat concussion more frequently returned to normal physical activities (98% vs 85%; difference = 13% [95% CI 4-28]; P < .0001) and sport (95% vs 82%; difference = 13% [95% CI 3-29]; P = .009). CONCLUSIONS: Most youth are symptom-free and fully recovered 1 year following concussion. Some children with repeat concussion have worse outcomes and have delays in returning to normal school routines and sport.

Pragmatic evaluation of a midstream urine collection technique for infants in the emergency department.

OBJECTIVES: Our objective was to examine the performance characteristics of a bladder stimulation technique for urine collection among infants presenting to the emergency department (ED). METHODS: This prospective cohort study enrolled a convenience sample of infants aged ≤ 90 days requiring urine testing in the ED. Infants were excluded if critically ill, moderately to severely dehydrated, or having significant feeding issues. Bladder stimulation consisted of finger tapping on the lower abdomen with or without lower back massage while holding the child upright. The primary outcome was successful midstream urine collection within 5 minutes of stimulation. Secondary outcomes included sample contamination, bladder stimulation time for successful urine collection, and perceived patient distress on a 100-mm visual analog scale (VAS). RESULTS: We enrolled 151 infants and included 147 in the analysis. Median age was 53 days (interquartile range [IQR] 27-68 days). Midstream urine sample collection using bladder stimulation was successful in 78 infants (53.1%; 95% confidence interval [CI] 45-60.9). Thirty-nine samples (50%) were contaminated. Most contaminated samples (n = 31; 79.5%) were reported as "no significant growth" or "growth of 3 or more organisms". Median bladder stimulation time required for midstream urine collection was 45 seconds (IQR 20-120 seconds). Mean VAS for infant distress was 22 mm (standard deviation 23 mm). CONCLUSIONS: The success rate of this bladder stimulation technique was lower than previously reported. The contamination rate was high, however most contaminated specimens were easily identified and had no clinical impact.

A Retrospective Case-Control Study to Identify Predictors of Unplanned Admission to Pediatric Intensive Care Within 24 Hours of Hospitalization.

OBJECTIVES: To identify the clinical findings available at the time of hospitalization from the emergency department that are associated with deterioration within 24 hours. DESIGN: A retrospective case-control study. SETTING: A pediatric hospital in Ottawa, ON, Canada. PATIENTS: Children less than 18 years old who were hospitalized via the emergency department between January 1, 2008, and December 31, 2012. Cases (n = 98) had an unplanned admission to the PICU or unexpected death on the hospital ward within 24 hours of hospitalization and controls (n = 196) did not. INTERVENTIONS: None. MAIN RESULTS: Ninety-eight children (53% boys; mean age 63.2 mo) required early unplanned admission to the PICU. Multivariable conditional logistic regression resulted in a model with five predictors reaching statistical significance: higher triage acuity score (odds ratio, 4.1; 95% CI, 1.7-10.2), tachypnea in the emergency department (odds ratio, 4.6; 95% CI, 1.8-11.8), tachycardia in the emergency department (odds ratio, 2.6; 95% CI, 1.1-6.5), PICU consultation in the emergency department (odds ratio, 8.0; 95% CI, 1.1-57.7), and admission to a ward not typical for age and/or diagnosis (odds ratio, 4.5; 95% CI, 1.7-11.6). CONCLUSIONS: We have identified risk factors that should be included as potential predictor variables in future large, prospective studies to derive and validate a weighted scoring system to identify hospitalized children at high risk of early clinical deterioration.

Clinical Risk Score for Persistent Postconcussion Symptoms Among Children With Acute Concussion in the ED.

IMPORTANCE: Approximately one-third of children experiencing acute concussion experience ongoing somatic, cognitive, and psychological or behavioral symptoms, referred to as persistent postconcussion symptoms (PPCS). However, validated and pragmatic tools enabling clinicians to identify patients at risk for PPCS do not exist. OBJECTIVE: To derive and validate a clinical risk score for PPCS among children presenting to the emergency department. DESIGN, SETTING, AND PARTICIPANTS: Prospective, multicenter cohort study (Predicting and Preventing Postconcussive Problems in Pediatrics [5P]) enrolled young patients (aged 5-<18 years) who presented within 48 hours of an acute head injury at 1 of 9 pediatric emergency departments within the Pediatric Emergency Research Canada (PERC) network from August 2013 through September 2014 (derivation cohort) and from October 2014 through June 2015 (validation cohort). Participants completed follow-up 28 days after the injury. EXPOSURES: All eligible patients had concussions consistent with the Zurich consensus diagnostic criteria. MAIN OUTCOMES AND MEASURES: The primary outcome was PPCS risk score at 28 days, which was defined as 3 or more new or worsening symptoms using the patient-reported Postconcussion Symptom Inventory compared with recalled state of being prior to the injury. RESULTS: In total, 3063 patients (median age, 12.0 years [interquartile range, 9.2-14.6 years]; 1205 [39.3%] girls) were enrolled (n = 2006 in the derivation cohort; n = 1057 in the validation cohort) and 2584 of whom (n = 1701 [85%] in the derivation cohort; n = 883 [84%] in the validation cohort) completed follow-up at 28 days after the injury. Persistent postconcussion symptoms were present in 801 patients (31.0%) (n = 510 [30.0%] in the derivation cohort and n = 291 [33.0%] in the validation cohort). The 12-point PPCS risk score model for the derivation cohort included the variables of female sex, age of 13 years or older, physician-diagnosed migraine history, prior concussion with symptoms lasting longer than 1 week, headache, sensitivity to noise, fatigue, answering questions slowly, and 4 or more errors on the Balance Error Scoring System tandem stance. The area under the curve was 0.71 (95% CI, 0.69-0.74) for the derivation cohort and 0.68 (95% CI, 0.65-0.72) for the validation cohort. CONCLUSIONS AND RELEVANCE: A clinical risk score developed among children presenting to the emergency department with concussion and head injury within the previous 48 hours had modest discrimination to stratify PPCS risk at 28 days. Before this score is adopted in clinical practice, further research is needed for external validation, assessment of accuracy in an office setting, and determination of clinical utility.

Management of Bronchiolitis in Community Hospitals in Ontario: a Multicentre Cohort Study.

OBJECTIVES: Bronchiolitis is the leading cause of hospital admission for infants, but few studies have examined management of this condition in community hospital settings. We reviewed the management of children with bronchiolitis presenting to community hospitals in Ontario. METHODS: We retrospectively reviewed a consecutive cohort of infants less than 12 months old with bronchiolitis who presented to 28 Ontario community hospitals over a two-year period. Bronchiolitis was defined as first episode of wheezing associated with signs of an upper respiratory tract infection during respiratory syncytial virus season. RESULTS: Of 543 eligible children, 161 (29.7%, 95% Confidence Interval (CI) 22.3 to 37.0%) were admitted to hospital. Hospital admission rates varied widely (Interquartile Range 0%-40.3%). Bronchodilator use was widespread in the emergency department (ED) (79.7% of patients, 95% CI 75.0 to 84.5%) and on the inpatient wards (94.4% of patients, 95% CI 90.2 to 98.6%). Salbutamol was the most commonly used bronchodilator. At ED discharge 44.7% (95% CI 37.5 to 51.9%) of patients were prescribed a bronchodilator medication. Approximately one-third of ED patients (30.8%, 95% CI 22.7 to 38.8%), 50.3% (95% CI 37.7 to 63.0%) of inpatients, and 23.5% (95% CI 14.4 to 32.7) of patients discharged from the ED were treated with corticosteroids. The most common investigation obtained was a chest x-ray (60.2% of all children; 95% CI 51.9 to 68.5%). CONCLUSIONS: Infants with bronchiolitis receive medications and investigations for which there is little evidence of benefit. This suggests a need for knowledge translation strategies directed to community hospitals.

Prognosticators of persistent symptoms following pediatric concussion: a systematic review.

OBJECTIVE To identify predictors of persistent concussion symptoms (PCS) in children following concussion. DATA SOURCES We searched MEDLINE, Embase, and the Cochrane Library to April 2012. STUDY SELECTION A systematic review of the literature to identify prognosticators of PCS following pediatric concussion was conducted. Studies evaluating patients aged 2 years to 18 years with PCS were eligible. MAIN OUTCOME MEASURES The association of clinically available factors with PCS development. RESULTS A literature search yielded 824 records; 561 remained after removal of duplicates. Fifteen studies were included in descriptive analysis; heterogeneity precluded a meta-analysis. Larger prospective studies concluded that the risk for PCS was increased in older children with loss of consciousness, headache, and/or nausea/vomiting. Smaller studies noted that initial dizziness may predict PCS. Patients with premorbid conditions (eg, previous head injury, learning difficulties, or behavioral problems) may also have increased risk. CONCLUSIONS Minimal, and at times contradictory, evidence exists to associate clinically available factors with eventual development of PCS in children. Future trials must be adequately powered to determine which variables best predict the time to full symptom resolution. Expert consensus should delineate which postconcussion assessment measures are preferred to reduce heterogeneity going forward. Research to improve care for the epidemic of pediatric concussion depends on early identification of those most in need of intervention.

Diagnostic coding of abuse related fractures at two children's emergency departments.

OBJECTIVES: Pediatric fractures suspicious for abuse are often evaluated in emergency departments (ED), although corresponding diagnostic coding for possible abuse may be lacking. Thus, the primary objective of this study was to determine the proportion of fracture cases investigated in the ED for abuse that had corresponding International Classification of Diseases (ICD) codes documenting abuse suspicion. Additional objectives were to determine the proportion of these fractures with admission ICD abuse coding, and physician text diagnoses recording abuse suspicion in the ED and/or admission notes. Factors possibly associated with abuse-related ED ICD codes were also examined. METHODS: Children less than three years of age that presented primarily with a fracture to two large academic children's hospitals from 1997 to 2007 and were evaluated for suspicion of abuse by child protective services were included in this retrospective review. The main outcome measure was the proportion of the fracture cases that had abuse suspicion reflected in ED discharge ICD codes. RESULTS: Of the 216 eligible patients, only 23 (11.5%) patients had ED ICD codes that included the possibility of abuse. Forty-nine (22.7%) had the possibility for abuse documented by physicians as an ED discharge diagnosis. In addition, 53/149 (35.6%) of all admitted patients and 34/55 (61.8%) of confirmed abuse cases included abuse-related admission ICD coding. Female gender was found to be a factor associated with ED ICD abuse codes. CONCLUSION: Current standards of ICD coding result in a significant underestimate of the prevalence of children assessed in the ED and hospital wards for possible and confirmed abusive fracture(s).