Pattern of leukocytes in the blood of healthy African neonates.

Serial leukocyte counts were performed on 107 full-term, 40 preterm and 35 postterm African neonates during the first 4 weeks of life. In addition, WBC differential counts were done on 85 of these neonates, selected randomly. Both the absolute and relative amounts of each cell type were determined. The main features of leukocyte counts during the neonatal period were: a mean leukocyte count of 12,580 cells/mm3 (range 3,500-20,500) on day 1, with no statistical difference observed between any two of the three groups studied; a decline in mean leukocyte count by day 7 which remained stable throughout the neonatal period, and a neutrophil count of 5,670 cells/mm3 (range 980-12,900) on day 1. This figure is much lower, both in relative and absolute numbers, than that reported for babies in Europe and North America. Lastly, the lymphocyte count was consistently higher than in comparable reports from Europe and North America. The constant leukocyte count, particularly that of neutrophils, may be of importance in detecting infected African neonates.