Clinical Outcomes in Pediatric COVID-19 Across Two Time Periods: The Role of Coinfection, Age, and Inflammatory Markers.

The COVID-19 pandemic is a widespread condition caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study examines the shifting epidemiology, risk factors for severe disease, and treatment approaches in pediatric SARS-CoV-2 infection. In this retrospective, single-center study, 275 children (aged 0-18 years) with confirmed SARS-CoV-2 infection (December 2023-December 2025) were analyzed. Demographic, clinical, laboratory, and microbiological data were collected. Of 275 patients, 40.0% were in Period 1 and 60.0% in Period 2. The overall hospitalization rate was 25.1%. Coinfection (17.8%) emerged as a key determinant of severity, being associated with higher hospitalization (40.8% vs. 21.7%) and PICU admission (12.2% vs. 3.5%). Lower respiratory tract involvement was the strongest clinical predictor of severe disease, with markedly increased hospitalization (51.1% vs. 18.3%) and PICU/intubation rates (22.2% vs. 2.0%). Infants (< 1 year) represented the highest-risk group across all severity indicators. Antibiotics were used in 45.5% of patients, but only 28.0% had a documented bacterial co-pathogen. Antibiotic use was associated with higher rates of hospitalization and PICU admission. Infants < 1 year showed the highest rates of hospitalization, PICU admission, pneumonia, and coinfection. Pediatric COVID-19 outcomes appear to be mostly influenced by coinfections, lower respiratory tract involvement, and younger age, with newborns being the most vulnerable group. The widespread use of empirical antibiotics emphasizes the need for more cautious and reasonable antimicrobial stewardship. Integrating readily available clinical findings with specific laboratory markers may enable earlier and more precise risk categorization, ultimately guiding tailored and effective treatment in children.