Infections are quite common, especially in long-term hospitalized patients. Eearly differential diagnosis of severe bacterial and viral
infections in patients in severe or critical condition is particularly important. Procalcitonin is a good and, above all, early marker of sepsis
and generalized inflammatory states. 85% sensitivity and 91% specificity of this study were shown in the differentiation patients with
systemic inflammatory response syndrome noninfectious and sepsis defined as a systemic inflammatory response syndrome induced
by infection. The usage of procalcitonin assays in clinical algorithms may accelerate the diagnosis of infectious conditions, reduce the
abuse of antibiotics and optimize therapy with these drugs. Therefore, the determination of procalcitonin concentration is increasingly
used in clinical practice.