The Face of Clostriodes Difficile Infections in the Outpatient Setting.

Background: It has long been well-established that Clostridiodes difficile infections (CDI) can cause severe morbidity and mortality. However, most of the literature to date has focused on hospital-diagnosed infections with less emphasis on clinic-based CDI cases. Guidelines from the 2010 IDSA/SHEA for CDI advocate for metronidazole as first-line therapy for mild to moderate CDI cases. However, the 2017 guidelines recommend oral vancomycin or fidaxomicin as first-line therapy due to their superior efficacy. Objective: The purpose of this study was to compare Clostriodes difficile infections in convenience samples of clinic vs. hospital patients.

Methods: In 2019, a retrospective, case-controlled study was performed by the first six authors between 2015-2017 (i.e., prior to the 2017 IDSA/SHEA CDI guidelines) to compare ambulatory and hospital CDI treatment prescriptions. Analytic data included frequency of White blood cells (WBC) and creatinine collection, frequency of severe CDI cases, compliance with the 2010 guidelines, CDI recurrence, and mortality.

Results: An eligible subgroup of N = 92 hospital patients at Spectrum Health Lakeland were more likely to have WBC (98.4% vs 32.6%, p<0.001) and creatinine (97.8 vs. 39.4, P < 0.001) drawn than 184 patients receiving clinic-based care. Hospital sampled patients were more likely to have severe CDI (46.7% vs 6.7%, p < 0.001). Mortality was less common in hospital patients (1.1% vs. 7.6%, p = 0.017) and the recurrence rates were similar. (21.2% inpatient vs. 28.3% outpatient, (p = 0.224).

Conclusions: Based on these results, assessment of CDI severity remains limited in the ambulatory population due to the lack of severity markers. It is unclear if this is due to lack of available laboratory resources or difference in clinical presentation. Of those sample patients who have available markers of severity, patients receiving clinic-based diagnoses were less likely assessed to have severe CDI. Keywords: Cloistriodes difficile infection, ambulatory, severity markers.