The measurement of monocyte volume width distribution (MDW) is intended for use with adult patients presenting to the emergency department (ED), where a CBC with Differential has been ordered, as an aid in the early detection of patients with or developing sepsis. The study will establish the clinical performance of MDW for detection of sepsis in the ED.

A prospective multi-center study to establish the clinical utility of the measurement of monocyte volume width distribution, a cell population parameter of the CBC-Differential, on the Beckman Coulter Unicel DxH analyzers. The study will validate the cut-off for the early detection of sepsis in an adult emergency room population where the standard of care included a CBC with Differential and will evaluate the diagnostic performance of the parameter.

Inclusion Criteria:

• Adults (18-89 years) presenting to ED
• All races & ethnicities
• CBC with Differential performed upon presentation
• Subjects with at least 12 hours of follow-up in ED (or in-patient if admitted)

Exclusion Criteria:

• Previously enrolled
• Subjects discharged <12 hours form ED presentation

All adult patients with suspicion who present to ED and for whom CBC with Diff is performed upon ED presentation.