Healthcare burden and age-specific severity of RSV pneumonia in children: policy implications

Background

The respiratory syncytial virus (RSV) causes most lower respiratory tract infections and seasonal paediatric hospitalisations. Despite increasing availability of preventive strategies, including maternal vaccination and monoclonal antibodies, regional data from Eastern Europe remain limited. This study examined the epidemiology, healthcare burdens, and prevention targets of RSV-associated pneumonia in hospitalised children.

Methods

A retrospective observational study was conducted at University Hospital Pulmed, Plovdiv (January - March 2026). The analysis included 134 children with lab-confirmed RSV pneumonia. Hospital records provide preliminary study data.

Results

The mean age was 3.3±4.7 years, and the mean length of hospital stay was 6.6±2.2 days. Hospitalisations increased from January (23.9%) to February (35.8%) and peaked in March (40.3%). Males accounted for 61.2% of cases, and 61.2% were hospitalised for the first time. Severe disease was observed in 38.8% of patients, while 65.7% required oxygen therapy. First-time hospitalisation was significantly associated with an increased need for oxygen therapy (72.7% vs. 39.1%, p < 0.001). A strong age gradient in severity was identified, with all children under 1 year requiring oxygen therapy compared to 64.0% of those aged 2–3 years and 2.6% of children aged ≥4 years (p < 0.001). Under 1 year olds had the highest rate of first hospitalisations (76.1%, p < 0.001).

Conclusions

RSV pneumonia imposes a substantial and highly age-concentrated burden on paediatric healthcare services. The concentration of severe disease among infants, particularly during primary infection, highlights a critical window for prevention. To reduce hospitalisations and seasonal strain on healthcare systems, immunoprophylaxis strategies like maternal vaccination and early-life protection should be prioritised. National child health policies must include RSV prevention to improve system preparedness and health outcomes.

Key messages

• RSV pneumonia in Bulgaria shows a strong age-dependent severity, with infants under 1 year accounting for the highest burden of severe disease and oxygen requirement.

• Targeted prevention strategies, including maternal vaccination and immunoprophylaxis in early infancy, are essential to reduce hospitalizations and improve healthcare system resilience.