[A] serum procalcitonin level may predict bacteremia in adult patients presenting with acute fever

ABSTRACT

Inspite of the high morbidity and mortality of bacteremia, in many instances clinical examination may not find a focus of infection nor can reliably identify cases of bacteremia. Moreover, laboratory parameters, such as C-reactive protein [CRP] level, erythrocyte sedimentation rate [ESR], and white blood cell [WBC] count lack accuracy for early diagnosis of bacteremic infection. The ability of serum procalcitonin [PCT] levels to differentiate bacteremic from nonbacteremic episode in patients admitted for community-acquired infection was assessed. We determined serum PCT and CRP levels, ESR and WBC count in 101 adult patients. Serum PCT levels were measured by immunoluminometric assay "BRAHMS Diagnostica, Berlin". CRP levels were determined by rate nephelometry. WBC count was determined in whole blood by an automated technique and ESR was performed by conventional Westergren method. According to results of blood cultures 23 [22.8%] patients were bacteremic and 78 [77.2%] patients constituted the nonbacteremic group. PCT and CRP levels, ESRs and WBC counts were significantly higher [P< 0.001] in the bacteremic than in the nonbacteremic group. Assay of serum CRP as well as ESRs and WBC counts showed a zone of overlapping values between the two groups. Receiver operating characteristic [ROC] curves were plotted for PCT and CRP serum levels to determine the optimal cut off points that maximized the sum of the sensitivity and specificity of each test. The best cut off value for PCT was 1microg/l which was associated with a negative predictive value [NPV] of 97.1%. Area under the receiver operating characteristic curve [AUROCC] was 0.98 for PCT which was significantly higher [P< 0.05] than that for CRP [0.89]. In comparison to CRP, ESR and WBC count, PCT at the cut off value 1microg/l could be a more effective predictor of bacteremia in patients admitted with community-acquired fever