Remember to look at the differential of your CBCs.  A recent publication demonstrated in retrospective data that higher proportions of bands on the WBC differential were associated with increased likelihoods of both severe bloodstream infections and mortality.1  The team retrospectively analyzed admitted patients with both a CBC with differential and blood cultures.  They found patients with 0% bands carried a 5% mortality while those with greater than 10% bands had over 20% mortality.  Bloodstream infections were particularly likely (just over 35%) in patients with greater than 10% bands.  So when you get that CBC, be sure to look at the differential - it may give you more clues than just the WBC.

Reference:

1. Hsueh, L., Molino, J. & Mermel, L. Elevated bands as a predictor of bloodstream infection and in-hospital mortality. The American Journal of Emergency Medicine (2020) doi:10.1016/j.ajem.2020.11.049.