Assessing Antimicrobial Stewardship in Paediatric Clostridioides difficile Positivity: To Treat or Not to Treat?

Background: Molecular syndromic stool panels are increasingly used in paediatric diarrheal syndromes; however, interpretation of Clostridioides difficile (C. difficile) detection remains challenging because colonisation is common in younger children. We aimed to assess the frequency of C. difficile detection using a syndromic gastrointestinal panel in a paediatric tertiary-care centre and to describe the subsequent microbiological work-up and CDI-directed treatment. Methods: We conducted a retrospective single-centre study of all BioFire FilmArray Gastrointestinal (GI) panels performed at San Marco Hospital (University Hospital “G. Rodolico-San Marco”, Catania, Italy) from 1 January 2023 to 31 December 2025. Only the first C. difficile-positive result per patient was included; repeat positives within 30 days were excluded. Index-positive episodes were stratified by age (<1 year, 1 to <2 years, and ≥2 years). Data collected included co-detected pathogens, toxin A/B enzyme immunoassay (EIA) results, GeneXpert PCR findings, and CDI-directed therapy. Results: Among the 714 GI panels performed during the study period, 112 (15.7%) were positive for C. difficile. After exclusion of repeat positives, 91 index-positive episodes were analysed. Median age was 1.0 years (IQR 0.75–4.0), and 48/91 cases (52.7%) occurred in children younger than two years. Toxin A/B EIA was positive in 11/82 tested episodes (13.4%), whereas GeneXpert tcdB was positive in 75/84 episodes (89.3%). Co-detection of at least one additional enteric pathogen occurred in 40/91 cases (44.0%). CDI-directed therapy was administered in 9/91 episodes (9.9%), mainly in children aged ≥2 years. Conclusions: Detection of C. difficile by syndromic molecular panels was relatively frequent in our paediatric cohort but rarely associated with toxin positivity or the need for specific treatment. These findings suggest that many positive Nucleic Acid Amplification Test (NAAT) results may represent colonisation rather than true infection, particularly in younger children. Careful clinical interpretation of syndromic panel results is therefore essential to avoid overdiagnosis and unnecessary antimicrobial therapy.