Screening of high risk patients for CPE in a Victorian tertiary referral centre: A pilot study

Abstract

Introduction: Screening of Carbapenemase producing Enterobacteriaceae (CPE) has recently been mandated by the Victorian Department of Health. Local experience in meeting these requirements is limited. Method: The pilot involved surveillance for 3 months in high risk clinical wards for carabapenemases and extended spectrum beta lactamases (ESBL). Screening was performed by rectal swabs in ICU, the Liver Transplant Unit and the Renal and Haematology Units. Samples were collected weekly in all wards except ICU which was tested twice weekly. Results: 2519 tests were performed, with 2273 negative results (90%). Of the 246 positive tests, 5 were due to carbapenemase producing organisms. Greater than 80% of acquired third generation cephalosporin resistant Enterobacteriaceae had ESBLs isolated. ESBL carriage by ward ranged from 6-13.8% patients tested with 3 wards exhibiting a greater than 12% prevalence. Conclusions: While there was no evidence of nosocomial transmission of carbapenemase producing bacteria during the study period, screening revealed five occasions where carbapenemase producing organisms were detected. Furthermore, based on our results, 2 of the 5 organisms were detected only as a consequence of the screening program as they did not have any of the conventional risk factors. Three of the five screened wards had a higher concentration of ESBL producing organisms implying previously undetected nosocomial transmission. Our results indicate more frequent screening than twice yearly testing is justified, and while costly, can be incorporated into standard work practices.