Clinical characteristics, pathogen detection, and severity markers among children with acute respiratory infections during the COVID-19 restriction period: a retrospective hospital-based study.

Background: The epidemiology of pediatric acute respiratory infections (ARIs) changed substantially during the COVID-19 (coronavirus disease 2019) pandemic, largely because of school closures, masking, reduced travel, and other non-pharmaceutical interventions (NPIs). However, hospital-based data from the restriction period remain useful for describing pathogen detection patterns, clinical severity, and markers of adverse clinical course. Methods: We conducted a retrospective hospital-based study of 62 children aged <18 years who were evaluated for ARI symptoms and underwent real-time fluorescent quantitative nucleic acid testing for common respiratory pathogens, including respiratory viruses and Results: The median age was 9 years (range, 1-17), and 33 patients (53.2%) were female. Most children had mild disease (37/62, 59.7%); 19 (30.6%) had moderate disease and 6 (9.7%) had severe disease. Intensive care unit (ICU) admission was recorded in 6 patients (9.7%), and mechanical ventilatory or noninvasive respiratory support in 9 (14.5%). Fever (43.5%) and cough (22.6%) were the most frequent presenting symptoms. Median oxygen saturation was 94.7% (range, 87.2-97.8). Respiratory virus detection was documented in 15 children (24.2%). Human rhinovirus was detected in 15 children (24.2%), human bocavirus in 9 (14.5%), and Conclusions: In this small hospital-based pediatric ARI cohort during the COVID-19 restriction period, severe disease was uncommon, and oxygen saturation and symptom duration were the most clinically coherent markers of greater severity. The observed pathogen detection pattern is compatible with pandemic-era disruption of respiratory pathogen circulation, but causal conclusions about NPIs require larger denominator-based studies with pre-pandemic and post-restriction comparison groups.