Background Following a relative absence in winter 2020, a large resurgence of respiratory syncytial virus (RSV) detections occurred during the 2020/2021 summer in Western Australia. This seasonal shift was linked to SARS-CoV-2 public health measures. We examine the epidemiology and RSV testing of respiratory-coded admissions, and compare clinical phenotype of RSV-positive admissions between 2019 and 2020. Method At a single tertiary paediatric centre, International Classification of Diseases, 10th edition Australian Modification-coded respiratory admissions longer than 12 hours were combined with laboratory data from 1 January 2019 to 31 December 2020. Data were grouped into bronchiolitis, other acute lower respiratory infection (OALRI) and wheeze, to assess RSV testing practices. For RSV-positive admissions, demographics and clinical features were compared between 2019 and 2020. Results RSV-positive admissions peaked in early summer 2020, following an absent winter season. Testing was higher in 2020: bronchiolitis, 94.8% vs 89.2% (p=0.01); OALRI, 88.6% vs 82.6% (p=0.02); and wheeze, 62.8% vs 25.5% (p<0.001). The 2020 peak month, December, contributed almost 75% of RSV-positive admissions, 2.5 times the 2019 peak. The median age in 2020 was twice that observed in 2019 (16.4 vs 8.1 months, p<0.001). The proportion of RSV-positive OALRI admissions was greater in 2020 (32.6% vs 24.9%, p=0.01). There were no clinically meaningful differences in length of stay or disease severity. Interpretation The 2020 RSV season was in summer, with a larger than expected peak. There was an increase in RSV-positive non-bronchiolitis admissions, consistent with infection in older RSV-naïve children. This resurgence raises concern for regions experiencing longer and more stringent SARS-CoV-2 public health measures.

RSV season onset and offset were defined as the point when RSV-positive detections per week crossed ≥1.2% year total.2 The 2020/21 year was centred on the peak 4 weeks. Respiratory infection coded admissions >12 hours between 1 January 2019 and 31 March 2021 were identified using hospital coding data.1 RSV-positive admissions were stratified by clinical diagnosis into bronchiolitis, other acute lower respiratory infection (OALRI), wheeze responsive to salbutamol (WRS) and other. Data collected, definitions and statistical analysis were performed as described.1

Background: Undifferentiated abdominal pain is a common pediatric presentation to the emergency department (ED). Objectives: The objective of this study was to describe the prevalence of clinically significant abdominal pathology (CSAP) including appendicitis, patterns of imaging and pathology tests, and management and outcomes of children with abdominal pain in ED. Methods: A prospective multicenter observational cohort pilot study of children under the age of 16 years presenting to 4 Australian EDs with abdominal pain was performed for a 1-month period at each site. The primary outcome was to describe the prevalence of CSAP and appendicitis. Age, sex, length of stay, surgery or interventional procedure, investigations, and analgesia use were recorded. Results: There were 555 presentations with abdominal pain during the study period with a median age of 9 years (interquartile range, 6–12 years). Eighty-two patients (14.8%; 95% confidence interval, 11.8–17.7) had CSAP, of which 41 (7.4%, 5.2–9.6) had appendicitis. Three hundred forty-eight (62.7%, 58.7–66.7) were discharged directly from ED, and 207 (37.3%, 33.2–41.3) were admitted. Two hundred fifty-five (45.9%, 41.8–50.1) had pathology tests, and 173 (31.2%, 27.3–35.1) had imaging tests in ED. Of those contacted for telephone follow-up, 100 (50.5%, 43.5–57.5) of 198 reported ongoing pain after discharge, and 13.1% (8.4–17.8) had missed over a week of school due to abdominal pain. Conclusions: The prevalence of CSAP and appendicitis in our study was 14.8% (11.8–17.7) and 7.4% (5.2–9.6), respectively. Fewer than half of patients received blood tests, and a third received imaging during their ED attendance. The presentation of abdominal pain conveys a significant health burden on families with time off school and ongoing symptoms of pain.

Respiratory syncytial virus (RSV) reinfection in children is poorly understood. We examined the incidence, characteristics, and outcomes of hospital-attended RSV reinfections in children <16 years in Western Australia between 2012 and 2022. Individuals with repeat RSV detections ≥56 days apart were identified using laboratory data. The incidence of reinfection in the first five years of life was estimated using the total birth population from 2012 to 2017. Clinical data on a subset of reinfection episodes were obtained from two metropolitan pediatric centers. A total of 466 children with hospital-attended reinfections were identified. The median interval between RSV detections was 460 days (interquartile range: 324, 812), with a reinfection rate of 95 per 100,000 individuals (95% confidence interval: 82, 109). Reinfection was most common in children who experienced their first RSV detection <6 months of age. Predisposing factors were identified in 56% of children; children with predisposing factors were older at first and second detections, were more likely to be admitted, and had a longer length of stay. This study highlights the significant burden of hospital-attended RSV reinfections in children with and without predisposing factors. Expanded surveillance with in-depth clinical data is required to further characterize the impact of RSV reinfection.

Objective: The objective was to investigate the feasibility of prospectively validating multiple clinical prediction scores (CPSs) for pediatric appendicitis in an Australian pediatric emergency department (ED).Methods: A literature search was conducted to identify potential CPSs and a single‐center prospective observational feasibility study was performed between November 2022 and May 2023 to evaluate the performance of identified CPSs. Children 5–15 years presenting with acute right‐sided or generalized abdominal pain and clinician suspicion of appendicitis were included. CPSs were calculated by the study team from prospectively clinician‐collected data and/or review of medical records. Accuracy of CPSs were assessed by area under the receiver operating characteristic curve (AUC) and proportions correctly identifiable as either low‐risk or high‐risk with the best performing CPS compared to clinician gestalt. Final diagnosis of appendicitis was confirmed on histopathology or by telephone/email follow‐up for those discharged directly from ED.Results: Thirty CPSs were identified in the literature search and 481 patients were enrolled in the study. A total of 150 (31.2%) patients underwent appendectomy with three (2.0%) having a normal appendix on histopathology. All identified CPSs were calculable for at least 50% of the patient cohort. The pediatric Appendicitis Risk Calculator for pediatric EDs (pARC‐ED; n = 317) was the best performing CPS with AUC 0.90 (95% confidence interval [CI] 0.86–0.94) and specificity 99.0% (95% CI 96.4%–99.7%) in diagnosing high‐risk cases and a misclassification rate of 4.5% for low‐risk cases.Conclusions: The study identified 30 CPSs that could be validated in a majority of patients to compare their ability to assess risk of pediatric appendicitis. The pARC‐ED had the highest predictive accuracy and can potentially assist in risk stratification of children with suspected appendicitis in pediatric EDs. A multicenter study is now under way to evaluate the potential of these CPSs in a broader range of EDs to aid clinical decision making in more varied settings.