Table 1 Study Characteristics

Hombach; Switzerland; 2010[24]

1 hospital; NR

Prospective cohort study; Copan^® swab; nose and groin

425 patients who i) arrived from or travelled to countries with known high rates of prevalence; ii) were transferred from LTC facilities; iii) were transferred from another health care facility; iv) were hospitalized within the previous 6 months; or v) had a history of MRSA colonization or infection

August 2007 to August 2008

Control arm: Broth-enriched (1 ml; tryptic soy broth [Becton Dickinson, Franklin Lakes, NJ, USA] supplemented with 7.5% NaCl and incubated for 24 h in ambient air 35°C. Swabs were subcultured on chromogenic agar medium (ChromIDMRSa agar; bioMérieux, Marcy l'Etoile, France) in ambient air 35°C

Intervention arm 1: BD GeneOhm MRSA assay (BD, san Diego, CA, USA) performed with a SmartCycler II (Cepheid, Sunnyvale, CA, USA) according to manufacturer's instructions

Intervention arm 2: Xpert MRSA assay (Cepheid, Inc., Sunnyvale, CA, USA)

Wassenberg; Netherlands; 2010[23]

14 hospitals;

government and industry

Prospective cohort study; swab not specified; anterior nares, throat and perineum

1,764 patients admitted to internal medicine, paediatrics, cardiology, neurology, and other (not specified) wards were included in the study. Patients admitted to the ICU were excluded from the BD GeneOhm MRSA study.

December 2005 to June 2008

Control arm: Conventional culture (not specified)

Intervention arm 1: BD GeneOhm MRSA PCR (BD Diagnostics, San Diego, CA, USA) run on the Cepheid Smart Cycler.

Intervention arm 2: Xpert MRSA assay (Cepheid, Sunnyvale, CA, USA)

Intervention arm 3: Chromogenic agar (MRSA-ID, bioMérieux, Marcy-l'Étoile, France)

Laurent; Belgium; 2010[17]

32-bed geriatric ward of a 390-bed tertiary-care hospital; industry

Prospective cohort study; Copan^® swab; nares

246 patients admitted to the geriatric ward, who presented at least one risk factor for MRSA colonization (i.e., antimicrobial therapy within the last 3 months, transfer from another hospital or from a nursing home, hospitalization in the previous year, presence of chronic wounds, past history of MRSA carriage or infection)

November 2007 to July 2008

Control arm: Chromogenic agar (CAM) MRSA Select (Bio-Rad, Marne La Coquette, France)

Intervention arm: Xpert MRSA assay on a GeneExpert DX system, version 1.2 (Cepheid) according to manufacturer's instructions

Creamer; Ireland; 2010[18]

1 acute care adult tertiary care referral hospital of 700 beds; government and industry

Prospective cohort study; Copan^® swab; nares and groin

567 patients who were previously MRSA-positive, transferred either internally or externally, had been hospitalized during the last 18 months and/or admitted to an ICU in the past 3 months. Patients with chronic wounds, underlying skin conditions, urinary catheters, stomas, or intravascular devices other than peripheral intravenous catheters were also included.

September 2008 to February 2009 during 3 time periods:

Period 1: 5-week observational period where at-risk patients for MRSA colonization were screened only with culture

Period 2: 10-week period where screening specimens were processed by culture and by a rapid PCR assay

Period 3: 5--week observational period where only culture was used for MRSA screening

During the study period, patients in the emergency department, medical wards and surgical wards were screened.

Periods 1 and 3: Patients were screened with direct culture on MRSASelect chromogenic agar plates (Bio-Rad Life Science Group)

Period 2: Xpert MRSA real-time PCR assay on the GeneXpert platform (Cepheid)

Snyder; US; 2010[19]

1 tertiary teaching hospital of 350 beds; none

Prospective cohort study; BBL CultureSwab; nares

Patients in ICU units, such as medical, surgical, neurological and cardiac

Number of patients = NR

Study duration = NR

Control arm: BBL CHROMagar MRSA medium (C-MRSA) and swab was then inoculated into enrichment broth, BBL tryptic soy broth with 6.5% NaCl (BD Diagnostics, Sparks, MD, USA)

Intervention arm: BD GeneOhm MRSA real-time PCR system (BD Diagnostics-GeneOhm, San Diego, CA, USA)

Pofahl; US; 2009[20]

1 tertiary care hospital of 761 beds; none

Prospective cohort study; swab not specified; nares

5,094 patients undergoing surgical infection prevention project procedures

Targeted screening = 56,835 operations

Universal screening = 35,778 operations

Period 1 (targeted screening) = January 1, 2004

Period 2 (universal screening) = February 15, 2007

Note: The end date of each study period was not reported.

Period 1: High-risk patients for MRSA carriage were screened on admission and placed in contact precaution prior to test results notification. MRSA screening test method for this phase was not specified.

Period 2: All admissions were screened for MRSA using BD GeneOhm, and patients were placed in contact precaution prior to notification of test results. Positive test results were confirmed with culture-based methods.

Hardy; UK; 2009[25]

1 teaching hospital of 1,200 beds; industry

Prospective, cluster two-period cross-over trial; swab not specified; nares

10,934 patients admitted to one of the study wards [general surgery (2), thoracic (1), ear, nose and throat (1), trauma and orthopedic (2) and urology (1)] for > 24 hours = 13,952 patient ward episodes (i.e., each separate ward admission for the same patient was counted.

1,270 (9.1%) PWE were excluded from the study analysis. [32 (0.2%) had no sample taken at admission and 1,238 (8.8%) had no sample taken at all]

January 2005 to April 2007 (2-month pilot period, two 8-month crossover periods and 1-month follow-up of study patients)

Control arm: chromogenic agar (MRSA ID; Biomerieux, Marcy, l'Étoile, France)

Intervention arm: BD GeneOhm MRSA (BD Diagnostics-GeneOhm, San Diego, CA, USA)

Where discrepant results occurred between chromogenic agar and PCR, samples were placed into broth enrichment and then sub-cultured onto chromogenic media.

Aldeyab, UK, 2009[26]

1 hospital; none

Cluster crossover trial; Copan swabs^®; nares, axillae and groin

Patients in medical⁄cardiology (2) and surgical (2) wards were studied.

Number of patients = NR

Phase 1: October 2006 to January 2007

Phase 2: February 2007 to May 2007

2-week washout period occurred between phases

Phase 1: Patients in surgical ward were screened using IDI-MRSA assay (BD GeneOhm, Oxford, UK) and patients in the medical⁄oncology ward were screened using chromogenic agar (MRSA-ID)*

Phase 2: Both wards switched screening methods*

Robicsek; US; 2008[21]

3-hospital organization; honoraria from industry

Prospective cohort study; swab not specified; nares

No active surveillance (i.e., no screening) = 39,521

ICU surveillance = 40,392

Universal surveillance = 73,427

August 2003 to April 2007

Period 1: Routine surveillance of MRSA did not occur

Period 2: Nasal surveillance for MRSA colonization for ICU admissions using an in-house screening method**

Period 3: Nasal surveillance for MRSA colonization for all hospital admissions on day one using BD GeneOhm

Jeyaratnam; UK; 2008[27]

1 hospital (2 sites); government

Cluster randomized crossover trial; swab not specified; nares, axillae and groin

9,608 patients were admitted to study wards: [surgical (6), elderly care (2), and oncology (2)].

(6,888 patients had full data and were eligible)

January 2006 to March 2007 (3-month baseline period, 5-month intervention period, 1-month washout period, and 5-month intervention period)

Control arm: swabs were taken on admission for culture only

Intervention arm: one swab used BD GeneOhm MRSA Assay and another swab used culture

Culture method: swabs were cultured in a selective broth and, after May 2006, were combined with Chromagar (Oxoid, Basingstoke, UK)

Jog; UK; 2008[22]

1 hospital; none

Prospective, cohort study; swab not specified; nares

1,462 patients admitted for cardiac surgery

October 2004 to September 2006

Control arm: chromID MRSA agar (bioMérieux, Marcy l'Étoile, France) and enrichment culture was performed after the assay procedure. For the broth enrichment, the swabs were incubated overnight in tryptic soy broth containing 6.5% NaCl at 35°C before subculture onto chromID MRSA and 5% sheep blood agar (Oxoid, Basingstoke, UK) with a 1 μg oxacillin disc.

Intervention arm: Gene Ohm MRSA Test (Becton Dickinson, New Jersey, USA) run on the Cepheid Smart Cycler.