Best marker for early septicemia:
Procalcitonin is a peptide naturally produced in the body that serves a marker for sepsis. In a healthy individual, procalcitonin is unlikely to be elevated. If a person is sick, and sepsis is suspected, the procalcitonin test would be ordered to determine, if there is widespread dissemination of the bacterial infection.
Key Concept:
PCT - best parameter for early sepsis diagnosis. Among the available laboratory parameters, PCT has been shown to be the most useful. PCT has been demonstrated to be the best marker for differentiating patients with sepsis from those with systemic inflammatory reaction not related to infectious cause.
PCT= Procalcitonin
C  reactive protein
Procalcitonin
D-dimer
All of the above