['Complete blood counts (CBC) performed for infected children admitted for fever mostly disclose leukocytosis. Yet, the recently developed XN-10', 'Blood samples from 90 children, 1 month to 5 years old, admitted to an emergency unit for fever benefited from a CBC, C-reactive protein, and procalcitonin assays. For 58, a bacterial infection was documented while a viral cause was disclosed for 32. Concomitantly, 30 healthy children of the same age range were selected as a control group.', 'Complete blood counts parameters and leukocyte differentials allowed to statistically significantly disclose infection, compared to reference children, in the age group of 1-5 years old. Among the eight novel discriminant parameters, a particular interest appeared for Neutr-RI and Delta-He. They both were successfully incorporated in a score together with age and immature granulocytes (IG). ROC curves and AUCs were calibrated using a Hosmer-Lemeshow test. Moreover, novel lymphocyte parameters allowed to segregate bacterial and viral infections in the whole group of 90 febrile children.'] Do new parameters on the hematology analyzer XN-10 ( SysmexTM ) allow to distinguish childhood bacterial and viral infections?