Enteric Pathogen Detection Using Multiplex PCR Assay in Kidney Transplant Recipients with Diarrhea—Retrospective Before–After Study

Introduction: Diarrhea is a frequent complication after kidney transplantation, however the etiology is often not identified. Multiplex PCR assays may increase the detection of diarrheal pathogens among kidney transplant recipients (KTRs), leading to improved management. Methods: This was a retrospective before–after study, conducted in a high-volume transplant center. In September 2017, multiplex PCR assay was introduced. We reviewed all hospitalized KTRs with diarrhea during 1/2015–8/2017 (pre-GI PCR, n = 111) and 9/2017–12/2021 (GI PCR, n = 159) and followed them for 3 years. We performed univariate and multivariate analysis for predictors of pathogen identification, introducing the study period as an independent variable. Results: Among 270 hospitalized KTRs with diarrhea, 64 (24%) had an identified diarrheal pathogen. The proportion of KTRs with an identified pathogen increased from 20% (13/64) in the pre-GI PCR to 80% (51/64) post GI PCR (p < 0.01). Of 51 KTRs with an identified pathogen in the post GI PCR, 44 (86%) were diagnosed using GI PCR. GI PCR was more likely used in younger KTRs with more recent transplantation and higher creatinine level at admission. The most common non-C. difficile diarrheal pathogens in the post-GI PCR cohort were enteropathogenic Escherichia coli (n = 23, 58%), norovirus (n = 11, 28%), and Campylobacter (n = 11, 28%). Implementing GI PCR significantly increased the detection and identification of GI pathogens (odds ratio [OR] = 21, CI 95% 10–44; p < 0.001). Conclusions: Infectious etiologies of diarrhea were identified in a higher proportion of KTRs after the implementation of GI PCR. This emphasizes the importance of integrating this diagnostic tool into diarrhea workup in KTRs.