Disease Burden of Respiratory Syncytial Virus in Korean Children A Nationwide Cohort Study

Background: Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in young children globally. This study aimed to characterize the epidemiology, clinical burden, and risk factors associated with RSV infection in South Korean children under 5 years of age. Methods: This nationwide, population-based retrospective cohort study utilized national health insurance claims data from 2007 to 2019. RSV cases were identified using relevant International Classification of Diseases, 10th Revision codes, and incidence, hospitalization, and outpatient visit rates were calculated. Logistic regression analysis identified risk factors for hospitalization. Results: A total of 185,823 RSV cases were identified, with an annual incidence of 286.0 to 822.9 per 100,000 children under 5. Hospitalization was required for 44.7% of cases. Infants under 6 months had the highest risk of hospitalization, longer hospital stays and higher medical costs. Logistic regression identified younger age, comorbidities and metropolitan residence as independent risk factors for hospitalization. Infants 6–11 months of age constituted the largest proportions of inpatient (48.2%) and outpatient (33.6%) cases, and highest number of intensive care unit admission. Conclusion: RSV infection places a substantial burden on young children in South Korea, particularly infants. High hospitalization rates underscore the need for targeted public health preventive interventions, enhanced surveillance and improved access to timely medical care, to mitigate RSV’s impact and improve child health outcomes.