Xpert c difficile pcr

CDI patients were retrospectively identified from the University of Virginia (UVA) Medical Center’s electronic database between 2013 to 2016. UVA Medical Center at the time used the Xpert C. difficile PCR (Cepheid, CA, USA) alone for CDI diagnosis. Clinical data were matched to discarded plasma and stool samples that were banked within 48 h of C. difficile testing by the microbiology laboratory. This study evaluated patients with newly diagnosed CDI; patients with a history of CDI within 90 days were excluded. Demographics (age, gender, and race) and clinical characteristics, such as white blood cell count and Charlson comorbidity index, were extracted from the electronic health record database. An immunosuppressant pharmacy grouper was used to identify receipt of immunosuppressants or systemic corticosteroids. Archived and available PCR cycle threshold (Ct) values were collected from the Xpert PCR machine. After initial storage at 4°C for a maximum of 24 h, samples were stored at −80°C until testing. The collection of patient data was approved by the institutional review board (protocol IRB-HSR 16926). This project met the criteria of research involving coded private information or biological specimens.

For detection of CDI, the C. diff Quick Check Complete EIA (TechLab; Blacksburg, VA, USA) had been used for C. difficile glutamate dehydrogenase antigen (GDH) and toxin A/B testing of non-formed stool samples as recommend by the manufacturer. GDH-positive, toxin A/B-negative samples had been retested by Xpert C. difficile PCR (Cepheid, Sunnyvale, CA).