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.