Abstract: Objective To analyze the clinical characteristics and prognosis of Clostridium difficile infection(CDI)in children of different age groups and to explore risk factors for disease recurrence. Methods Clinical data from 63 children with initial CDI admitted to Childrens Hospital of Shandong University from January 2019 to December 2024 were retrospectively analyzed. Patients were divided into infant group(n=29,<3 years)and child group(n=34,3-12 years). Based on post-treatment recurrence, they were further categorized into recurrence group(n=11)and non-recurrence group(n=52). Employing statistical methods such as the Mann-Whitney U test and χ2 test, this study compared clinical data between two groups, summarized clinical and endoscopic characteristics, and identified risk factors for CDI recurrence through binary logistic regression analysis, with the predictive value of these factors for recurrence evaluated using receiver operating characteristic(ROC)curve analysis. Results Diarrhea and hematochezia were most common in infant group, while diarrhea, abdominal pain, and hematochezia predominated in child group. The incidence of abdominal pain(73.52 % vs. 34.48%)and erythrocyte sedimentation level ［7.00(3.75,10.25)mm/h vs. 3.00(2.00,5.00)mm/h］were significantly higher in child group than infant group(P<0.05). All patients underwent colonoscopy. The colonoscopy positivity rate was 62.06% in infant group(predominantly mild), and 64.70% in child group(predominantly moderate). The infant group exhibited a lower degree of endoscopic severity compared to the child group(P<0.05). Patients received single or combined anti-CDI therapy. At 2-month follow-up, there was no significant difference in recurrence rates(17.24% vs. 17.65%)between two groups(P>0.05). Further analysis of recurrence(11 cases)and non-recurrence(52 cases)groups showed higher rate of inflammatory bowel disease(36.36% vs. 1.92%), higher white blood cell count［(12.72±2.44)×10⁹/L vs.(8.89±3.15)×10⁹/L］, higher C-reactive protein［11.49(7.31,13.67)mg/L vs. 3.20(1.56,3.65)mg/L］, higher fecal calprotectin ［341.90(226.80,431.00)μg/g vs. 89.30(29.03,183.28)μg/g］ levels in recurrence group(P<0.05)and lower serum prealbumin ［(139.00±26.87)mg/L vs.(170.70±46.27)mg/L］ in recurrence group(P<0.05). Binary logistic regression identified high fecal calprotectin(OR=1.009, 95%CI:1.001-1.017)was anindependentrisk factor for recurrence in children with CDI. ROC curve analysis demonstrated that fecal calprotectin predicted recurrence with an area under the curve of 0.886, a sensitivity of 0.727, a specificity of 0.942, and an optimal cut-off value of 300.30 μg/g. Conclusion Clinical symptoms and inflammatory markers of CDI vary minimally between age groups, but colonoscopy severity differs. High fecal calprotectin may be an independent risk factor for recurrence, warranting clinical attention.

Key words: Children, Clostridium difficile infection, Clinical manifestations, Colonoscopic features, Risk factors