CALCA and Sepsis: To this end, we conducted electronic research in the PubMed database from September 2018 to September 2023, using “sepsis” OR “severe bacterial infection” AND “infant” OR “children” OR “pediatric” OR “paediatric” OR “biomarker” OR “blood culture” OR “blood cell count” OR “neutrophil count” OR “ANC” OR “C-reactive protein“ OR “CRP” OR “procalcitonin” OR “PCT” OR “inflammatory markers” OR “cytokine“ OR “IL-2” OR “IL-6” OR “IL-10” OR “IL-27” OR “soluble triggering receptor” OR “sTREM-1” OR “platelet” OR “TRAIL” OR “IP-10” OR “presepsin” as keywords.