Abstract

Introduction: Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections (LRTIs) in infants and young children. This study evaluated clinical and laboratory factors associated with prolonged hospitalization in pediatric RSV infection.

Methods: This retrospective study included children under 18 years of age hospitalized with LRTI and confirmed RSV infection at our center between 2023 and 2025. Demographic, clinical, and laboratory data were collected from hospital records. Patients were divided into two groups according to length of stay (LOS): ≤2 days and >2 days. Multivariate logistic regression analysis was performed using the backward stepwise method.

Results: A total of 185 RSV-infected children were analyzed. The median age was 2 months, and 51.9% were male. Patients with LOS >2 days had significantly higher rates of PICU admission, non-invasive ventilation, mechanical ventilation, and secondary bacterial infections. Laboratory findings showed higher lymphocyte counts and BUN levels in the prolonged-stay group, whereas MPV levels were lower. No mortality was observed. In the multivariate logistic regression analysis, PICU stay was associated with approximately 12-fold increased risk of hospitalization longer than 2 days.

Conclusion: Hospitalization longer than 2 days was associated with a more severe clinical course. In the multivariate logistic regression analysis, PICU stay was the main factor associated with hospitalization longer than 2 days. Lymphocyte count, MPV, and BUN may provide supportive clinical information; however, their independent prognostic value remains uncertain.