Evaluation of Diagnostic Value of Procalcitonin as a Marker of Neonatal Bacterial Infections

Objective: This study tried to assess sensitivity, specificity, positive and negative predictive value of procalcitonin for diagnosis of neonatal bacterial infections.
Methods: This prospective cross sectional study was carried out during an 18-month period in NICU and neonatal wards of Besat Hospital in Hamedan province, Iran. 39 symptomatic infants with clinical and laboratory findings in favor of bacterial infection with a positive blood, CSF, and/or supra pubic urine culture entered the study; 32 newborns without any bacterial infection served as control group. Quantitative procalcitonin level ≥0.5 ng/ml was accepted as pathological. Finally sensitivity, specificity, positive (PPV) and negative predictive value (NPV) were calculated for procalcitonin test.
Findings: 20 blood cultures, 17 urine cultures and 8 CSF cultures were positive. Sensitivity, specificity, PPV and NPV for procalcitonin test was 76.9%, 100%, 100% and 78% respectively. Diagnostic value of procalcitonin test in accordance with blood culture for mentioned items was 85%, 100%, 100% and 91.4% respectively. Its diagnostic value according to urine culture was: sensitivity 70.6%, specificity 100%, PPV 100% and NPV 86.4%, and according to CSF culture was: sensitivity 75%, specificity 100%, PPV 100% and NPV 94.1% respectively.
Conclusion: The results show that the procalcitonin test has high sensitivity, specificity, PPV and NPV for diagnosis of neonatal infections.

Keywords
Infection; Newborn; Procalcitonin; Sensitivity; Specificity; Predictive Value of Tests