Performance of the Xpert® Carba-R v2 in the daily workflow of a hygiene unit in a country with a low prevalence of carbapenemase-producing Enterobacteriaceae.

Abstract

Early detection of patients colonised with carbapenemase-producing Enterobacteriaceae (CPE) is crucial for implementing proper infection control measures. Here we evaluated the biological performance of the Xpert® Carba-R v2 (Cepheid) in the daily workflow of a hygiene unit in a country with a low CPE prevalence. Patients repatriated from countries known for high CPE prevalence or contact patients of a known CPE carrier were targeted as being 'high-risk patients' for CPE carriage. Between September 2015 and March 2016, 241 'high-risk patients' for CPE carriage were screened using the Xpert® Carba-R v2 and by plating on chromID® CARBA Smart medium (bioMérieux) with and without ertapenem-containing enrichment culture for 24 h. Of these patients, 81.7% were previously hospitalised abroad and 18.3% were contact patients of known CPE carriers. The Xpert® Carba-R v2 was able to detect 12 OXA-48-like, 1 KPC and 1 OXA-48-like/NDM carriers. For 2 of the 14 Xpert® Carba-R v2-positive samples, cultures remained negative even on two additional screenings (performed at Days 4 and 7). The Xpert® Carba-R v2 presents 100% sensitivity, 99.13% specificity, 85.71% positive predictive value and 100% negative predictive value. This study demonstrated that the Xpert® Carba-R v2 kit is well adapted for rapid screening of high-risk patients even in low prevalence regions (in <1 h versus 24/48 h for culture). This assay may guide infection control programmes to limit the spread of CPE.