Discordant Clostridioides difficile diagnostic assay and treatment practice: a cross-sectional study in a tertiary care hospital, Geneva, Switzerland

OBJECTIVES: To determine the proportion of patients who received a treatment for Clostridioides difficile infection (CDI) among those presenting a discordant C. difficile diagnostic assay and to identify patient characteristics associated with the decision to treat CDI. DESIGN: Cross-sectional study. SETTING: Monocentric study in a tertiary care hospital, Geneva, Switzerland. PARTICIPANTS: Among 4562 adult patients tested for C. difficile between March 2017 and March 2019, 208 patients with discordant tests’ results (positive nucleic acid amplification test (NAAT+)/negative enzyme immunoassay (EIA−)) were included. MAIN OUTCOME MEASURES: Treatment for CDI. RESULTS: CDI treatment was administered in 147 (71%) cases. In multivariate analysis, an abdominal CT scan with signs of colitis (OR 14.7; 95% CI 1.96 to 110.8) was the only factor associated with CDI treatment. CONCLUSIONS: The proportion of NAAT+/EIA− patients who received treatment questions the contribution of the EIA for the detection of toxin A/B after NAAT to limit overtreatment. Additional studies are needed to investigate if other factors are associated with the decision to treat.