Comparison of Clinical and Laboratory Features Between COVID-19 and Community-Acquired Pneumonia in Children

Community-acquired pneumonia (CAP) is a common respiratory tract infection in children that is caused by various pathogens, including bacteria, Mycoplasma pneumoniae (MP), respiratory syncytial virus (RSV), and SARS-CoV-2, which was the most widespread causative pathogen in recent years. We compared pathogen-specific CAP to identify shared and distinct host responses. This single-center, retrospective cohort study enrolled 200 children hospitalized for CAP caused by SARS-CoV-2, MP, RSV and bacterial infections from January 2019 to February 2023. We included only patients with mild symptoms and performed propensity score matching to adjust for age and sex. Patients with CAP due to COVID-19 were more prone to fever and poor appetite ( P < 0.01) but had a lower incidence of cough and moist and wheezing rales ( P < 0.01) and a shorter disease course ( P < 0.01). The frequencies of antibiotic, anti-inflammatory drug and oxygen therapy use were lower in the CAP-COVID-19 group than in the non-COVID-19 CAP groups ( P < 0.01). Additionally, white blood cell, lymphocyte and eosinophil counts were lower in the CAP-COVID-19 group than in the non-COVID-19 CAP groups ( P < 0.01). However, the procalcitonin levels in the CAP-COVID-19 group were higher than those in the CAP-bacteria ( P < 0.05) and CAP-MP groups ( P < 0.01). Moreover, we observed significant differences in nutritional status (total protein and albumin), renal function (serum creatinine and urea) and myocardial function (creatine kinase and creatine kinase-MB) between the CAP-COVID-19 and CAP-MP groups. Our results revealed shared and distinct pathophysiological features across pathogen-specific CAP, enabling precise diagnosis and treatment.