Neonatal Sepsis: Any Role for Procalcitonin as a Diagnostic Marker?

Introduction In low and middle-income countries, a key driver of neonatal morbidity and mortality is neonatal sepsis. Rapid and precise diagnosis of neonatal sepsis remains a critical challenge due to limited laboratory facilities. Blood culture results, the diagnostic gold standard is often unavailable/delayed; therefore Procalcitonin (PCT) is been considered as a potential inflammatory biomarkerof bacterial infection.This study assessed the diagnostic performance of PCT in neonates with sepsis at the Federal Teaching Hospital Owerri, Nigeria. Methods This cross-sectional study recruited 75 neonates aged 0–28 days with clinical suspicion of sepsis between June 2023 and February 2024. Sociodemographic and clinical data were obtained using a structured questionnaire, serum PCT levels were measured using Enzyme-linked immunosorbent assay (ELISA) and blood culture was performed as the gold standard. Diagnostic indices (sensitivity, specificity, positive predictive value (PPV), negative predictive value, NPV) were calculated at different PCT thresholds. Receiver Operating Characteristic (ROC) curves was analyzed to determine the area under the curve (AUC). Results Of the 75 neonates, 55 (73.3%) had culture-confirmed sepsis and 32 (58.2%) early-onset neonatal sepsis.A PCT cutoff of ≥ 2 ng/mL demonstrated a sensitivity and NPV of 72.7% and 57.1%. Specificity and PPV remained 100% for all the neonates. The AUC for PCT was significantly higher in EONNS (0.964, 95% CI: 0.910–1.000) compared to LONNS (0.788, 95% CI: 0.638–0.938). Gram-negative organisms (63.6%) were the most common isolates, mainly Escherichia coli (34.5%). Conclusion Serum Procalcitonin is a very specific biomarker for establish neonatal sepsis especially at a cutoff of ≥ 2 ng/mL. Its diagnostic precision is higher in EONNS compared to LONNS. PCT measurement integration in Nigeria can be a priceless tool for guiding rational antibiotic therapy; particularly where rapid confirmation of sepsis is critical to improving neonatal survival outcomes.