Procalcitonin as a Diagnostic Biomarker for Bacterial Gastroenteritis: A Retrospective Analysis

Background/Aim: Bacterial and viral gastroenteritis present with overlapping symptoms, including vomiting, diarrhea, and abdominal pain. Stool tests have been used to differentiate between them; however, stool cultures are time-consuming and stool polymerase chain reaction (PCR) tests are expensive. The role of the clinical value of procalcitonin (PCT) as a diagnostic marker of bacterial gastroenteritis remains to be investigated. This study evaluated the diagnostic value of PCT for the early diagnosis of bacterial gastroenteritis. Methods: The medical records of patients diagnosed with gastroenteritis by the emergency department with positive stool PCR results confirming the diagnosis between January 1, 2020, and July 31, 2024, were retrospectively reviewed. Demographic characteristics and laboratory findings, including the PCT and C-reactive protein (CRP) levels, were analyzed. The area under the curve (AUC) for the diagnosis of bacterial gastroenteritis was assessed to determine the diagnostic potential of PCT. Results: Among the 1,882 cases identified, 1,435 met the inclusion criteria. CRP exhibited superior diagnostic performance for diagnosing bacterial gastroenteritis in general, with an AUC of 0.848 (95% CI, 0.815–0.881; p<0.001). However, in patients aged >17 years with fever (≥38°C), PCT was the only significant inflammatory marker, and the AUC of PCT was 0.767 (95% CI: 0.603–0.932; p=0.019). Conclusions: CRP is effective in predicting bacterial gastroenteritis; however, PCT may serve as a valuable biomarker for the early diagnosis of febrile adult patients. Further large-scale studies must be conducted to validate these results and improve diagnostic strategies.