The impact of toxigenic culture on antimicrobial prescriptions for Clostridioides difficile infection: The role of diagnostic stewardship.

Abstract

Introduction : Toxigenic culture has been recommended as a sensitivity enhancement option for testing Clostridioides difficile infections (CDI). However, no studies have evaluated whether toxigenic culture impacts clinical decisions such as CDI treatment. Methods : At Nara Medical University Hospital, simultaneous testing of glutamate dehydrogenase antigen (A) and toxin A/B (T) by immunochromatography has been conducted since November 2013. Furthermore, toxigenic culture (C) has been adopted since April 2018. Therefore, patients tested for CD were divided into two groups: pre-period from April 2014 to March 2018 and post-period from April 2018 to March 2021. Patient data were retrospectively examined. Results : The study included 1262 and 1023 cases in the pre- and post-periods, respectively. A significant reduction in A+T+ cases could be observed with 64 (5.1 %) and 28 (2.7%) in the pre- and post-periods (P = 0.005), respectively. Of the 104 A+T- cases undergoing toxigenic culture in the post-period, 54 (51.9 %) were A+T-C+. The antimicrobial administration ratio for the A+T-C+ cases (68.5 %) was lower than that for the A+T+ patients (90.6 and 82.1 %, P = 0.014 and P = 0.417, in the pre- and post-periods, respectively), and was not significantly different from that of the A+T-patients (64.2 and 64.1 % in the pre- and post-periods, respectively) or from that of the A+ T-C-patients (64 %). Conclusion : This study showed that toxigenic culture does not necessarily affect the antibiotic administration ratio or duration. A coordinated approach under diagnostic stewardship for improved reporting and interpretation of toxigenic cultures would be necessary.