Reduction in the rate of methicillin-resistant Staphylococcus aureus acquisition in surgical wards by rapid screening for colonization: a prospective, cross-over study

Abstract

Identification of patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) and subsequent isolation and decolonization is pivotal to the control of cross infection in hospitals. The aim of this study was to establish if early identification of colonized patients using rapid methods alone reduces transmission. A prospective, cluster, two-period cross-over design was used. Seven surgical wards at a large hospital were allocated to two groups, and for the first 8 months four wards used rapid MRSA screening and three wards used a standard culture method. The groups were reversed for the second 8 months. Regardless of the method of detection, all patients were screened for nasal carriage on admission and then every 4 days. MRSA control measures remained constant. Results were analysed using a log linear Poisson regression model. A total of 12 682/13 952 patient ward episodes (PWE) were included in the study. Admission screening identified 453 (3.6%) MRSA-positive patient ward episodes, with a further 268 (2.2%) acquiring MRSA. After adjusting for other variables, rapid screening was shown to statistically reduce MRSA acquisition, with patients being 1.49 times (p 0.007) more likely to acquire MRSA in wards where they were screened using the culture method. Screening of surgical patients using rapid testing resulted in a statistically significant reduction in MRSA acquisition. This result was achieved in a routine surgical service with high bed occupancy and low availability of isolation rooms, making it applicable to the majority of health-care systems worldwide.

Evaluation of the BD GeneOhm Assay Using the Rotor-Gene 6000 Platform for Rapid Detection of Methicillin-Resistant Staphylococcus aureus from Pooled Screening Swabs

“…Rapid screening for MRSA has been shown to reduce transmission and cross-infections in surgical and ICU patients (4,11,12). This is important given that each surgical site infection is estimated to cost an average of £4,200 (22) and is associated with significant increases in length of stay and mortality (3, 10).…”

“…These offer significant advantages over culture, which takes 2 to 5 days to produce a positive result, and their use has been associated with reduced transmission of MRSA in both intensive care unit (ICU) and surgical settings (4,11,12). One of the most widely used commercial screens, the BD GeneOhm MRSA assay (BD Diagnostics, Becton Dickinson, NJ), simultaneously detects targets in the staphylococcal cassette chromosome mec (SCCmec) and S. aureus-specific orfX genes.…”

Performance of the BD GeneOhm MRSA Achromopeptidase Assay for Real-Time PCR Detection of Methicillin-Resistant Staphylococcus aureus in Nasal Specimens

“…MRSA detection is often followed by either decolonization or isolation to reduce MRSA prevalence within hospitals and in the community (4,8,10). In an elegant crossover study of the impact rapid testing has on MRSA transmission, Hardy and colleagues demonstrated significantly reduced transmission when surveillance testing was done using a real-time PCR assay, as opposed to no significant impact when routine, culture-based testing was utilized by the laboratory (9). Thus, rapid and reliable screening tests for MRSA detection are very important.…”

Detection of Methicillin-Resistant Staphylococcus aureus by a Duplex Droplet Digital PCR Assay

“…Once colonized patients are identified, a health care institution can isolate colonized patients, begin decolonization, and notify staff of the need for increased attention to hand hygiene (5,6,7,8). The major contributor to the success of infection control policies is the turnaround time (TAT) advantage of PCR-based methods, which is typically 2 to 4 h, compared to standard microbiological cultures using selective agars, which is usually 24 to 48 h. In one study in surgical wards, MRSA transmission was shown to be significantly reduced when culture-based testing in the laboratory was replaced by real-time PCR assays (9). Real-time PCR-based assays have been proven to lead to a reduction in the incidence of MRSA disease (10,11,12).…”