It is widely believed mat an increased number of immature neutrophils (bands) in the peripheral blood smears (PBS) of febrile children is indicative of bacterial illness. In order to assess whether the number of bands in the PBS in young febrile children helps to distinguish between viral and occult bacterial illnesses, we prospectively evaluated 331 children under 2 years of age presenting to the emergency department with either fever without obvious source, or fever with bronchiolitis. Blood was obtained for complete blood count, differential and culture from all patients and urine was obtained for culture from all females, and all males under 6 months of age. Chest radiographs were obtained from all patients with signs of lower respiratory infection, and a nasopharyngeal probe was obtained for isolation of respiratory syncytial virus (RSV) from all consented patients. White blood cell (WBC), absolute neutrophil (ANC), absolute band (ABC) counts, and % bands on the PBS were compared between the 27 patients with RSV-positive bronchiolitis and the 26 patients with culture-proven bacterial illness (21 with urinary tract infection and 5 with bacteremia). Logistic regression analysis was performed to identify independent predictors of bacterial illness when comparing these two groups. Bacterial Illness RSV Bronchiolitis P-value * WBC (x103/mm3)+ 17.7(17.6) 13.1(12.1) <01 4mean(median) ANC (x103/mm3)+ 11.3 (12.2) 5.6 (5.0) <001 values given ABC (x103/mm3)+ 2.1(1.9) 1.8(1.2) .14 * Wilcoxon rank % Bands+ 13.7 (11.5) 12.6 (10) .40 sum test When the variables age, temperature, WBC, ANC and ABC were entered into the regression analysis, only ANC (P=.01) and temperature (P=.02) were significantly associated with bacterial illness. We conclude that neither the % band count nor the absolute band count were significantly different between patients with occult bacterial illness and RSV-positive bronchiolitis. Similar comparisons involving other documented viral infections may be necessary to confirm the lack of utility of routine inspection of peripheral blood smears in young, febrile children.
|Original language||English (US)|
|Journal||Journal of Investigative Medicine|
|State||Published - 1996|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)