Abstract
Background and Objectives: Respiratory syncytial virus (RSV) is a leading cause of hospitalization among infants and young children. The clinical course of RSV infection varies considerably depending on age and selected clinical factors. The objective of this study was to identify demographic and clinical variables associated with the course of hospitalization in children admitted due to laboratory-confirmed RSV infection. Materials and Methods: A retrospective observational study was conducted based on the medical records of 100 immunocompetent pediatric patients hospitalized due to RSV infection in the Department of Pediatrics of Hospital in Wadowice, Poland, between December 2021 and April 2023. Inclusion criteria were age ≤ 5 years and laboratory-confirmed RSV infection. Patients with congenital heart disease, chronic lung disease (including cystic fibrosis), immunodeficiency, or other severe chronic conditions were excluded. Collected data included age, gestational age at birth, mode of delivery, vaccination status, clinical presentation, length of hospital stay, C-reactive protein (CRP) levels, seasonality of infection, and use of antibiotic therapy. Results: The median length of hospitalization was 6 days (range: 0-18). Younger age was significantly associated with longer hospital stay (p < 0.05) and higher CRP levels (p < 0.05). No significant associations were observed between hospitalization duration and mode of delivery or vaccination status. Gestational age at birth did not influence the number of clinical symptoms. The need for antibiotic therapy differed significantly according to the season of infection (p < 0.05). Conclusions: In children hospitalized with RSV infection, age and seasonality were the primary factors influencing the course of hospitalization, whereas perinatal factors such as mode of delivery and vaccination status had no significant impact. These findings underscore the importance of age-oriented clinical assessment and support efforts to optimize antimicrobial stewardship during RSV seasons.