Antibiotic overuse in children with leukemia and association with intestinal disorders caused by Candida albicans infection

Background: Children with the diagnosis of leukemia face a high risk of opportunistic invasive fungal infections due to chemotherapy-induced immunosuppression. Inappropriate use of antibiotics has complicated this because, especially in low-income and middle-income countries like Iraq, it is well established that antibiotics alter gut microbiota and can lead to opportunistic infections like oral and gastrointestinal Candida albicans infections. Objective: The aim to analyze the prevalence, risk factors, and microbiological profile of intestinal fungal infections – specifically C. albicans in children with leukemia, and to examine the impact of antibiotic overuse in Najaf, Iraq. Methods: One hundred children aged 1–18 who had leukemia and ongoing gastrointestinal symptoms were recruited for this prospective observational study, which ran from September 2024 to April 2025. PCR identification, fungal culture, and microscopy were performed on stool and blood samples. Chi-square tests and logistic regression were used in the statistical analysis. Results: Fungal infections were found in 34% of patients, mostly Candida spp. (76.5%), with C. albicans being the most frequent (50% of Candida isolates). Aspergillus fumigatus and other molds accounted for 14.7% (5/34). There were no discernible sex-based variations in the distribution of fungi ( P > 0.05). Prolonged carbapenem use (>14 days) independently increased the odds of C. albicans colonization [odds ratio (OR) 4.0, 95% confidence interval (CI): 1.2–12.8, P = 0.02]. Prolonged neutropenia (>14 days) was also a significant risk factor (OR 2.3, 95% CI: 1.0–5.7, P = 0.04). Conclusion: In children with leukemia, overuse of antibiotics is closely linked to increased intestinal colonization by C. albicans . These results emphasize the necessity of early fungal screening methods and targeted antimicrobial stewardship, especially in low-resource environments.