Objectives Staphylococcus aureus (SA) infections are a common problem in children and a frequent reason for paediatric infectious diseases (PID) consultation. We sought to describe contemporary practices of Canadian PID physicians for management of serious paediatric SA infections.Methods We developed and disseminated a national, self-administered, cross-sectional online survey of Canadian PID consultants to assess practice patterns involving the management of serious paediatric SA infections.Results Thirty-nine of 84 (46%) PID consultants across 14 Canadian children's hospitals completed the survey; 48.7% (n = 19) had been practising for 10 or more years and 92.1% (n = 35) completed their PID training in Canada. For methicillin sensitive SA (MSSA) infections outside the central nervous system, 56.4% (n = 22) of respondents preferred cefazolin. Ceftriaxone/cefotaxime was used as definitive treatment for MSSA by 26.3% (n = 10). Prescribing penicillin for penicillin sensitive SA was divided with 51.3% (n = 20) choosing to use it. Most respondents chose to treat SA bacteremia (SAB) with no focus in immunocompetent children and neonates for 14 days, 89.7% (n = 35) and 92.3% (n = 36), respectively. Variability was observed in the practices of ordering abdominal ultrasounds and echocardiograms for SAB with no focus, and in the transition to oral antibiotics for MSSA bacteremia. Variability was also noted in treating osteoarticular infections with methicillin resistant SA bacteremia, with 56.4% (n = 22) choosing intravenous antibiotics until an appropriate clinical response is observed while others advised a minimum 7 (17.9%, n = 7) or 14 (12.8%, n = 5) day intravenous course.Conclusion Our study highlights both areas of consistency and variability among Canadian PID physicians in managing serious SA infections in children, emphasizing the need for evidence-based paediatric guidelines and increased inclusion of children in clinical trials.

BACKGROUND:The COVID-19 pandemic affected the epidemiology of respiratory syncytial virus (RSV). We sought to describe tertiary care hospital admissions associated with pediatric RSV in 2022/23 in Canada and to assess pandemic-related changes. METHODS:We conducted active surveillance of hospital-admitted infants and children aged 0 to 16 years at 13 Immunization Monitoring Program, Active (IMPACT) centres. We compared RSV-associated hospital admissions in 2022/23 with those in the prepandemic period (2017/18 through 2019/20). We calculated province-specific and age-stratified proportions of all-cause hospital admissions with RSV detection and age-stratified proportions of RSV-associated intensive care unit (ICU) admissions. We performed seasonal autoregressive integrated moving average (SARIMA) time-series analyses. RESULTS:In 2022/23, 5362 RSV-associated hospital admissions occurred, including 1260 (23.5%) ICU admissions, both more than double the prepandemic yearly averages. Overall, the median age increased from 6 (interquartile range [IQR] 1 to 20) months to 9 (IQR 2 to 27) months (p < 0.001). The proportion of RSV-associated hospital admissions among all-cause admissions increased by 3.5 percentage points (95% confidence interval [CI] 3.3 to 3.7 percentage points), to 6.8% (95% CI 6.6% to 7.0%). Whereas 41.5% of RSV-associated hospital admissions were among infants younger than 6 months, this age group accounted for 62.1% of ICU admissions. Overall, the ICU proportion remained constant; however, the odds of ICU admission among infants younger than 6 months increased (adjusted odds ratio 1.35, 95% CI 1.2 to 1.52) compared with the prepandemic period. National weekly incidence in 2022/23 peaked earlier and higher, and persisted longer than expected by SARIMA. INTERPRETATION:In 2022/23, the number of RSV-associated hospital admissions and ICU admissions increased dramatically in Canadian pediatric hospitals. The greatest burden remained in infants younger than 6 months. Strategies for RSV immunization for young infants may have a substantial public health impact.

BackgroundRespiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections and hospitalizations among infants in Canada. New long-acting monoclonal antibodies (mAbs) and vaccines administered during pregnancy have expanded prevention options, yet the most cost-effective immunization program remains uncertain.MethodsWe updated a Canadian cost-utility model to evaluate seven seasonal RSV prevention strategies over one year (with a lifetime horizon for mortality impacts), from health system and societal perspectives. Strategies included RSVpreF vaccination in late pregnancy; targeted or universal infant mAb programs using nirsevimab or clesrovimab; and combination programs in which infants could receive protection from either RSVpreF or mAbs. Sequential incremental cost-effectiveness ratios (ICERs) were estimated in 2024 Canadian dollars per quality-adjusted life year (QALY), using a $50,000/QALY threshold. The primary analysis used immunization product list prices.FindingsThe most cost-effective strategy was a seasonal combination program: RSVpreF vaccination for pregnancies due during the RSV season, with mAb for infants at high risk (<32 weeks' gestation), including catch-up for infants at high risk born before the season. This strategy had an ICER of $35,408/QALY compared to seasonal mAb for infants at moderate risk (320/7 to 366/7 weeks' gestation) or high-risk with catch-up. Expanding mAb to unimmunized non-high-risk infants born in-season increased the ICER to $132,131/QALY. Universal infant protection, with mAb alone or combined with RSVpreF in pregnancy, was not cost-effective across analyses. RSVpreF alone was dominated. Results were most sensitive to product prices, target populations, age at administration, and RSV burden.ConclusionsA seasonal combination program with RSVpreF for in-season deliveries and mAb for infants at high risk of RSV offers the best value for money for protecting Canadian infants from RSV disease. Broader infant immunization programs may be cost-effective with substantial price reductions or in regions with higher disease burden and healthcare costs.

The incidence of congenital (CS) in Canada increased from 2.1 to 14.5 reported confirmed cases/100,000 live births from 2017 to 2023 (from 8 to 53 cases). We aimed to document prenatal characteristics and contributing factors to CS among mothers or birthing parents (M/BP) of infants with CS in Canada. Participants of the Canadian Paediatric Surveillance Program, which includes both paediatricians and paediatric subspecialists, were invited to report on CS cases meeting the study case definition between June 2021 and May 2023. A detailed questionnaire was completed by the reporting clinician. We used descriptive statistics in the assessment of prenatal risk factors among cases, including data on healthcare access, diagnosis, and treatment as well as on socio-demographic, socio-economic and socio-behavioural determinants. During the 24-month study period, 245 live-born cases of CS were reported, including 81 (33.1

Necrotizing soft tissue infection (NSTI) caused by Haemophilus influenzae type B (Hib) is rare and life-threatening. We report severe monomicrobial Hib NSTI in a 16-month-old Inuit child who had received 3 doses of the Hib vaccine, highlighting vaccine failure and host susceptibility. The child sustained a minor fall to the left thigh without skin breakdown and developed fever the same day, initially treated with amoxicillin for presumed acute otitis media. He re-presented with persistent fever, progressive leg pain, swelling, ecchymosis, and refusal to weight-bear, prompting air transfer to the regional hospital and the initiation of ceftriaxone. Investigations showed C-reactive protein >90 mg/L, a white blood cell count of 13.6 ×10⁹/L, normal creatine kinase, and unremarkable radiographs. Owing to concern for necrotizing infection, the patient was transferred to a tertiary pediatric intensive care unit. Antimicrobials were escalated to piperacillin-tazobactam, vancomycin, and clindamycin, and intravenous immunoglobulin was administered. Emergent surgical debridement demonstrated extensive dermal and subcutaneous necrosis with preserved fascia and muscle. Blood and tissue cultures grew Hib. He required mechanical ventilation, inotropic support, and multiple additional debridements prior to skin grafting. Household contacts received chemoprophylaxis. Immunologic evaluation was unremarkable; genetic testing was non-diagnostic. NSTI requires prompt recognition, surgical debridement, and targeted antimicrobial therapy. While most cases are due to group A Streptococcus or polymicrobial infections, Hib is rare, with few pediatric cases reported. Vaccine failures occur, particularly before the 18-month booster, reflecting waning immunity. Indigenous populations remain disproportionately affected. Invasive Hib disease despite vaccination warrants evaluation for underlying immunodeficiency. Invasive Hib infection should be considered even in fully vaccinated children. Continued surveillance, prompt surgical management, public health response and investigations of host susceptibility remain essential.

Background Nunavut is a northern Canadian territory where a high proportion of infants are admitted to hospital with acute respiratory tract infection (ARI). Previous studies have been limited in regional and/or short duration of coverage. This study aimed to estimate the incidence rate, microbiology and outcomes of ARI hospitalizations in Nunavut infants. Methods We conducted a retrospective cohort study of infants aged <1 year from Nunavut hospitalized for ARI at two regional and four tertiary pediatric hospitals in Canada, January 1, 2010, to June 30, 2020. One regional hospital was located in Nunavut; others were located across Canada. Descriptive statistics and multivariable logistic regression were performed. Findings We identified 1189 ARI admissions, with an incidence rate of 133.9 per 1000 infants per year (95% confidence interval (CI): 126.8, 141.3). Of these admissions, 56.0% (n = 666) were to regional hospitals alone, 72.3% (n = 860) involved hospitalization outside of Nunavut, 15.6% (n = 185) were admitted into intensive care, and 9.2% (n = 109) underwent mechanical ventilation. Among 730 admissions with a pathogen identified, 45.8% had respiratory syncytial virus (RSV; n = 334), for a yearly incidence rate of 37.8 RSV-associated hospitalizations per 1000 infants (95% CI: 33.9, 42.1). Among RSV-associated hospitalizations, 41.1% (n = 138) were infants 0-2 months of age and 32.1% (n = 108) were >6 months. Compared with non-RSV admissions, infants with RSV had higher odds of admission into intensive care, oxygen therapy, CPAP/BiPAP respiratory support and length of hospital stay over a week. Interpretation Understanding the high burden of ARI among Nunavut infants can inform health policy and serve as a baseline for assessing the impact of any new interventions targeting infant ARIs. Funding Public Health Agency of Canada and Canadian Institutes of Health Research via the Canadian Immuni- zation Research Network (CNF 151944). Copyright (c) 2025 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Background:Respiratory syncytial virus (RSV) is a major cause of bronchiolitis and pneumonia in pediatric populations, especially in infancy. This study aims to assess overall and age-specific incidence of RSV-associated hospitalization and healthcare resource use throughout childhood in Canada. Methods:Data were retrieved from a national administrative dataset, which captured hospitalizations with International Classification of Diseases (ICD) codes, tenth revision from participating Canadian hospitals (Canadian Institute for Health Information, CIHI), and from an active surveillance program in tertiary care pediatric hospitals (the Canadian Immunization Program ACTive, IMPACT). Children aged 0-16 years with RSV in November 2017 through April 2023 were eligible. We estimated overall and age-specific RSV hospitalization incidence, healthcare resource use (length of stay, mechanical ventilation use), and costs by age group (0-5, 6-11, and 12-23 months, and 2-4 years, 5-9 years, 10-16 years). Costs were adjusted to 2022 Canadian dollars (CAD). The population denominator for age-specific RSV incidence estimates was retrieved from Statistics Canada. Findings:An estimated 29,277 RSV hospitalizations occurred, with an average of 5831 cases/year in pre-pandemic years (November 2017-June 2020). Infants aged <6 months old accounted for 13,055 (44.6%) of cases for study duration (November 2017-April 2023). RSV incidence among infants aged <6 months increased from 1250 per 100,000 in November 2017-June 2018 to 2393 per 100,000 in July 2022-April 2023. The average annual cost of RSV was $66,267,950 CAD. Infants <6 months old accounted for 49.0% ($32,471,296 CAD) of annual average RSV healthcare costs. Interpretation:Although RSV occurs throughout childhood, the high RSV hospitalization incidence in infants younger than 6 months of age highlights an urgent need for prevention strategies in this population to alleviate the health burden in this population and economic burden on healthcare systems. Funding:This surveillance activity is conducted as part of the Canadian Immunization Monitoring Program Active (IMPACT), a national surveillance initiative managed by the Canadian Paediatric Society (CPS) and conducted by the IMPACT network of pediatric investigators. Funding for RSV surveillance was provided by the Public Health Agency of Canada; funding for RSV economic burden analyses was provided by Sanofi and AstraZeneca.

PURPOSE OF REVIEW:Congenital syphilis continues to result in devastating adverse pregnancy and infant outcomes globally, with significant rises noted in recent years in high-income countries (HIC). Prenatal screening and prompt treatment for syphilis in pregnant persons are important in contributing to healthy pregnancy outcomes, particularly in equity-denied populations. However, the implementation of these recommendations remains challenging, even in HIC. RECENT FINDINGS:Although antenatal screening guidelines for syphilis universally recommend screening in pregnancy, the implementation of these recommendations has been challenging. In HIC, individuals grappling with poverty, unstable housing, addictions, and mental health concerns often encounter significant barriers to accessing essential healthcare services. Innovative approaches, such as the use of rapid/point-of-care tests, opportunistic screening, and community-based or outreach testing, are essential to reach key equity-denied populations. It is crucial to include members of key populations and community-based organizations in the design of interventions to effectively reach these populations. SUMMARY:Given the resurgence of congenital syphilis in some regions, especially in HIC, we must address this preventable cause of maternal and fetal morbidity and mortality effectively. Collaboration between all levels of government and health services and the inclusion of key equity-denied populations is crucial.