Blood neutrophil response to bacterial infection in the first month of life

Abstract

Serial white blood cell counts were undertaken on 100 babies who required admission to hospital in the first 4 weeks of life. Severe neutropenia was seen in 3 babies who died with overwhelming septicaemia, but a significant and early rise in the absolute polymorphonuclear neutrophil count was detected in 9 of the remaining 11 cases of septicaemia. A similar neutrophil response was seen within 24 hours of the onset of symptoms in 5 babies with meningitis, 10 babies with urinary infection, and 5 babies with pneumonia. Raised neutrophil counts were seen in only 9 of the remaining 66 babies, and all 9 had undergone major surgery.

In more than 98% of healthy babies the neutrophil count is within the range 1350 to 8840 cells/mm³ after the first 4 days of life; counts outside this range nearly always occur during serious bacterial infection.