788 - Evaluation of a Multiplex PCR Panel and Confirmatory Cytotoxin Testing on Clostridioides difficile at a Pediatric Hospital

Background: With the introduction of gastrointestinal multiplex PCR (mPCR) tests, clinicians have received an increased number of positive tests for Clostridioides difficile. Patients who test positive via mPCR may not have a positive toxin assay indicative of true infection and may not need antibiotics. The goal of this study was to assess the symptoms of patients who test positive for C. difficile and determine the impact on antibiotic use at a pediatric hospital.

Methods: A single-center, retrospective review was completed from May 2018 to March 2020. Initial C. difficile screening tests were performed via an mPCR test or a mono-PCR test. Patients > 1 year of age had a reflex cytotoxin assay performed. The primary outcome was the difference in symptoms between cytotoxin positive and negative patients. Secondary outcomes included co-pathogen detection on mPCR and C. difficile antibiotic days of therapy.

Results: Four hundred and sixty-one patients were included in our chart review. 49% of patients had a positive mPCR for a GI pathogen (n=229), and 18% (n=82) were positive for C. difficile. Cytotoxin was positive for 45% of patients that had C. difficile on mPCR. 34% of patients that had C. difficile detected on mPCR also had co-pathogens detected. No significant differences were present in symptomatology between cytotoxin positive and negative patients and no significant differences between white blood cell count (Table 1). There was a significant difference in the number of patients treated for the C. difficile between the cytotoxin populations (p-value< 0.05). The average duration of treatment with a negative test was significantly less than for positive cytotoxin test patients (7.5 vs 11 days, p-value< 0.05).Table 1: Comparison of cytotoxin production in pediatric patients with Clostridioides difficile.


Conclusion: Our results show a significant amount of antibiotic use for patients with cytotoxin negative C. difficile and no differences in symptomatology or white blood cell count based on cytotoxin positivity. Diagnostic stewardship of mPCR tests may be needed to effectively impact this unneeded antibiotic use, specifically the duration.