Correlating CBC profile and infectious outcome. A study of febrile infants evaluated for sepsis.

The cases of 1,009 febrile infants who were evaluated for sepsis as outpatients during a seven-year period were reviewed to correlate their complete blood count (CBC) profiles with the infectious outcomes. Eighty-one infants had serious bacterial infections (SBIs); the remainder (928) were culture-negative. The infants with SBIs had a significantly greater mean total white blood cell (WBC) count and absolute band count (ABC) than did those who were culture-negative, whereas the difference in mean percent of polymorphonuclear leukocytes was not significant. The sensitivity of the ABC was significantly superior to that of total WBC count in predicting the outcome of SBI. The diagnostic data provided by the ABC can aid physicians in determining the predictive value of CBC profiles for infectious outcome in febrile infants receiving outpatient sepsis evaluation.