Hospital burden of Respiratory Syncytial Virus in children in Spain (2016-2022): A retrospective study.

Respiratory Syncytial Virus (RSV) is a leading cause of acute lower respiratory tract infections, particularly in children under two years of age. This study aimed to estimate the population-based burden of RSV-related hospitalizations in individuals under 19 y in Spain from 2016 to 2022. A retrospective analysis was conducted using national hospital discharge data. Hospitalization rates, mortality, case fatality, and associated healthcare costs were analyzed by age group and year. A total of 166,046 RSV-related hospitalizations were recorded (57.36% male), with 94.60% in children under 5 y and 66.22% in infants under 1 y. The highest mean hospitalization rate was observed in infants <1 y (4,367.87 per 100,000), increasing to 5882.06 in 2022. Mortality was highest in infants <1 y (2.9 per 100,000), while the highest case fatality rates occurred in the 10-14 (0.89%) and 15-19 (0.92%) age groups. Children <5 y with comorbidities had significantly higher case fatality (0.76%) compared to those without (0.02%; OR=31.76). Hospitalization and mortality rates were lowest during the COVID-19 pandemic years. The mean cost per hospitalization was €3,169.63 for children <5 y and €3,276.50 for infants <1 y. The total cost exceeded €497 million, with €360 million attributed to infants <1 y. RSV imposes a substantial burden on the pediatric population in Spain, particularly among infants. These findings underscore the need for effective preventive strategies, including immunization and early intervention.