MRSA Transmission in Intensive Care Units: Genomic Analysis of Patients, Their Environments, and Healthcare Workers

Background Methicillin-resistant Staphylococcus aureus (MRSA) —and now USA300 MRSA—is a significant intensive care unit (ICU) pathogen; healthcare worker (HCW) contamination may lead to patient cross-transmission. Methods From September 2015 to February 2016, to study the spread of MRSA, we enrolled HCWs in 4 adult ICUs caring for patients on MRSA contact precautions. Samples were collected from patient body sites and high-touch surfaces in patient rooms. HCW hands, gloves, and personal protective equipment were sampled pre/post-patient encounter. Whole genome sequencing (WGS) was used to compare isolates from patients, HCWs, and environment. Results There were 413 MRSA isolates sequenced (38% USA300, 52% USA100) from 66 patient encounters. Six of 66 HCWs were contaminated with MRSA prior to room entry. Isolates from a single patient encounter were typically either USA100 or USA300; in 8 (12%) encounters both USA300 and USA100 were isolated. WG S demonstrated that isolates from patients, HCWs, and environment often were genetically similar, although there was substantial between-encounter diversity. Strikingly, there were 5 USA100 and 1 USA300 clusters that contained similar strains (
Source: Current Awareness Service for Health (CASH) - Category: Consumer Health News Source Type: news