Differences in polymorphonuclear cell counts between healthy white and black infants: response to meningitis.

Both black adults and black children have significantly lower total WBC counts and absolute polymorphonuclear WBC counts than do white adults and white children. In an effort to determine whether similar differences existed in infancy, 50 health black infants and 50 white infants were examined. The black infants, 9 to 12 months of age, were found to have significantly lower total WBC counts, absolute neutrophil counts, and absolute lymphocyte counts. In ten of the 50 black infants, the absolute neutrophil counts were less than 1,000/microL; none of the white infants had absolute neutrophil counts of less than 1,000/microL. Even in the presence of a serious infection, meningitis, significantly fewer black infants had absolute neutrophil counts greater than 10,000/microL than did their white counterparts.