Dr Chris Connor2,3, A/Prof Torsten Seemann2,3, Dr Marcel Leroi1,4, Prof Benjamin Howden1,2,3, A/Prof Norelle Sherry1,2, A/Prof. Jason Kwong1,2
1Department of Infectious Diseases & Immunology, Austin Health, Australia, 2Department of Microbiology & Immunology, University of Melbourne, Australia, 3Centre for Pathogen Genomics, University of Melbourne, Australia, 4Department of Microbiology, Austin Health, Australia
Biography:
A/Prof Jason Kwong is an Infectious Diseases Physician and Director of Infection Prevention & Control at Austin Health. He is chair of HICSIG within the Australasian Society for Infectious Diseases and is an associate editor for Infection, Disease & Health. His research interests include genomics for surveillance/control of infectious diseases.
Abstract:
Introduction
Screening for multidrug-resistant bacterial organisms (MDRO) has been used to identify colonized patients and initiate contact precautions to prevent transmission to other patients. However, the benefit is gained from screening is unclear. We investigated the effectiveness of different strategies to identify MDRO transmission.
Methods
We undertook a post hoc analysis of a prospective observational study in our hospital. Hospital inpatients were actively screened for MDRO including vancomycin resistant E. faecium (VRE), and extended-spectrum beta-lactamase-producing E. coli (ESBL-EC) and K. pneumoniae (ESBL-KP) across a 15-month period, with non-screening MDRO isolates from clinical infections also included in the study. MDRO isolates underwent genome sequencing to identify putative transmission events (PTE), which were correlated with epidemiological data.
Results
668 MDRO isolates (81 vanA VRE, 489 ESBL-EC, 98 ESBL-KP) were identified from 15,305 samples, with 524 unique patients yielding a positive screening result. Among 59 patients (11.3%) who had both a positive screening swab and a MDRO clinical infection during the study period, screening swab isolates preceded clinical infections by a median of 18 days (IQR 4–67 days). 13/165 (7.9%) MDRO from clinical samples were genomically linked, suggestive of transmission. The addition of screening samples identified an additional 503 MDRO isolates, of which 118 (23.5%) represented PTE.
Conclusions
Sole reliance on detecting MDRO from clinical samples misses a significant number of MDRO cases and PTE when compared to active screening. Further research is required to determine whether implementing contact precautions for cases identified through active screening reduces transmission and prevents subsequent clinical infections.