Inflammatory Markers in Pediatric Bacterial Sepsis vs. SARS-CoV-2 Infection: A Retrospective Study

Early differentiation between bacterial sepsis and viral infection in pediatric patients is critical for timely and appropriate therapy. We compared the inflammatory markers C-reactive protein (CRP), fibrinogen, erythrocyte sedimentation rate (ESR), and D-dimer in children with bacterial sepsis and those with SARS-CoV-2 infection to discern characteristic profiles. Methods: We retrospectively analyzed 97 pediatric sepsis cases (culture-confirmed bacterial infections) and 100 pediatric COVID-19 cases (RT-PCR-confirmed SARS-CoV-2). The initial inflammatory marker levels were extracted from the medical records. Statistical comparisons of means and medians were performed, with significance set at p<0.05. Results: CRP levels were markedly higher in bacterial sepsis (mean 8.1mg/dL, median 7.4mg/dL) than in COVID-19 (mean 4.1mg/dL, median 3.35mg/dL; p<0.001). ESR was also elevated in sepsis (mean 46mm/h) versus COVID-19 (mean 26mm/h; p<0.001). Fibrinogen showed the opposite pattern, being significantly lower in sepsis (mean 304.7mg/dL, median 267mg/dL) than in COVID-19 (mean 421mg/dL, median 448mg/dL; p<0.001). D-dimer was high in both groups; the COVID-19 cohort had a higher mean D-dimer (3.2?g/mL) with considerable variability, whereas the sepsis cohort’s D-dimer was slightly lower and more homogeneous (difference not statistically significant). Conclusions: Pediatric bacterial infection and COVID-19 exhibit distinct inflammatory marker profiles. Sepsis induces a more intense CRP and ESR response, whereas COVID-19 is characterized by markedly elevated fibrinogen and variable D-dimer levels.