Effects of causative organism and presence or absence of meningitis on white blood cell counts in children with bacteremia.

The records of 182 children with bacteremia due to Streptococcus pneumoniae, Haemophilus influenzae type b, or Neisseria meningitidis were reviewed to determine which variables other than the presence or absence of bacteremia might affect patients' white blood cell (WBC) counts. There were no significant or consistent effects of age, sex, race, or duration of illness on WBC counts. Significantly lower mean WBC counts were noted for patients with, versus those without, meningitis and patients with H influenzae type b bacteremia versus those with S pneumoniae bacteremia. As a screening test for bacteremia, the WBC count is less useful in children with either meningitis or infection caused by H influenzae type b than in children with nonmeningeal infections caused by S pneumoniae.