[Gastrointestinal PCR Panel Results and Evaluation of Inflammatory Biomarkers in Acute Gastroenteritis Cases]

Acute gastroenteritis (AGE) is an important public health problem that is very common all over the world. Knowing the causative agents is important for understanding the clinical course of the disease, effective treatment and necessary precautions to be taken. In this study, we aimed to determine the pathogen distribution in AGE cases admitted to our center using multiplex real-time polymerase chain reaction (mRt-PCR) and to demonstrate the clinical and laboratory differences between luminal (type I) and mucosal/invasive (type II) infections. We also aimed to define biomarker thresholds to facilitate decision-making in situations where access to advanced diagnostic tests is limited. Eighty-five patients aged ≥ 18 years were retrospectively analyzed between June and September 2023. Clinical complaints, stool macroscopy and laboratory results recorded at admission including; leukocyte count, neutrophil/ lymphocyte ratio (NLR), hemoglobin, platelet count, C-reactive protein (CRP), renal and hepatic function tests and lactate dehydrogenase (LDH) values were recorded. Stool samples were evaluated by microscopic examination, culture/antigen tests and Bio-Speedy Gastroenteritis mRt-PCR (MX-24L). According to PCR results, the cases were categorized as a pathogen-negative group, a mucosal-type infection group and a luminal-type infection group. Appropriate statistical tests were used, ROC analysis was performed for CRP, NLR and platelet count to predict mucosal type. The median age was 54 years (interquartile range= 38-67) and 56.5% were male. At least one pathogen was detected by PCR in 76% (65/85) of the cases; the most common were Campylobacter spp. (17.3%), enteroinvasive Escherichia coli (12.9%) and norovirus (12.9%). 41.2% of the cases were mucosal type, 35.3% were luminal-type and 23.5% were in the group in which no causative agent was detected. Age was higher in the mucosal type group (p= 0.009). Red color/blood in stool and fever were significantly more common in mucosal type group (both p< 0.001); vomiting was more common in mucosal type group (p= 0.016). CRP and NLR values were significantly higher in mucosal type group (both p≤ 0.001), while platelet count was lower (p= 0.021). ROC analysis revealed CRP as the strongest predictor for mucosal type group. mRt-PCR enables high-rate detection of acute gastroenteritis pathogens, supporting accurate and early treatment and contributing to a reduction in unnecessary antibiotic use. By using this test, the most frequently identified acute gastroenteritis pathogens in our region were detected as Campylobacter, norovirus and EIEC. In settings where these tests are not available, CRP levels ≥ 42.5 mg/L and/or NLR ≥ 3 may serve as indicators in favor of mucosal-type pathogens and thrombocytopenia may further support this clinical profile. The use of simple and easily accessible biomarkers in combination with clinical findings may contribute to more effective field management of AGE cases.