This study is intended to clinically verify Monocyte Distribution Width (MDW) parameter of DxH 900 Hematology Analyzer for use in early detection and risk assessment of sepsis, severe sepsis, and septic shock in critically ill patients in Emergency Department (ED). This study is also aimed to provide study supporting data for the product to be marketed in China.

To verify the clinical performance of MDW parameter in detection of sepsis through a multicenter, prospective study of adults undergoing complete blood count with differential ("CBC with differential") in the ED.

To clarify the cutoff 20.0 established in the pivotal trial. The cutoff was established for the objective of achieving the highest sensitivity at the optimal specificity level. Patients whose MDW value is higher than the cutoff will be identified as sepsis patients and those whose MDW value is equal to or lower than the cutoff are non-sepsis patients.

Inclusion Criteria:

• Adult subjects (18-89 years) presenting to ED.
• CBC with Differential performed upon presentation as part of standard of care.
• Subject scheduled for at least 12 hours follow-up during ED (or inpatient, if admitted to the hospital) visit
• Signed the informed consent form

Exclusion Criteria:

• Subjects previously enrolled in this study (i.e., re-enrollment to this study is not allowed).
• The subject is discharged from the hospital within 12 hours after ED visit

Patients of any race and ethnicity can be enrolled to this study. Patients with a prior chronic immunosuppressive disease and subjects with hematological malignancy can also be enrolled. This study requires at least 250 sepsis subjects and 1,100 non-sepsis subjects.