Early diagnosis of bacterial infections is a challenge to the clinicians as well as to the laboratory. Bacteriological culture is the gold standard for the diagnosis of bacterial infections. However, the process of isolating the bacteria and determining its antibiotic susceptibility takes a minimum of 48 hrs. This duration presents a very big challenge to clinicians in respect to the choice of therapy. More over, prior antibiotic therapy often results in negative bacterial culture results.In healthy individuals, PCT is produced by the thyroid cells called the c-cells. Its production is regulated by the body’s calcium requirements. In normal health, entirely all PCT produced by the c-cells of the thyroid glands is converted into calcitonin. So very little amount of PCT is seen in the circulation (less than 0.5ng/ml).
The level of PCT rises rapidly after a bacterial infection with systemic consequences. Thus evaluating PCT concentrations, the physicians are able to engage in the risk assessment for progression to severe sepsis and septic shock.