Epidemiology, Outcomes and Resource Utilisation in Patients with Carbapenem Non-susceptible Gram-Negative Bacteria in the UK: A Retrospective, Observational Study (CARBAR UK).

INTRODUCTION: Antimicrobial resistance is an urgent medical challenge. In this two-part study, we investigated the epidemiology and management of carbapenem non-susceptible (Carb-NS) Gram-negative bacteria (GNB) in the UK. METHODS: We conducted a retrospective review of data from UK hospitals (ten in part 1, nine in part 2). In part 1, epidemiological data were collected from patients hospitalised between April 2017 and March 2018 with any laboratory detection of Carb-NS GNB, encompassing both colonisation and infection. In part 2, diagnosis and management pathways in a randomly selected population of adults from part 1 with confirmed Carb-NS GNB infection were assessed. Data were obtained from a detailed medical chart review for ≥ 3 months from index (collection date of first positive Carb-NS GNB sample). RESULTS: Of 42,340 GNB isolates from 36,098 patients colonised/infected with GNB in part 1, 7% were Carb-NS. In 157 patients included in part 2, 234 GNB index samples were collected, of which 197 (82%) were Carb-NS (median number of Carb-NS pathogens per patient, 1; range 1-3). The most frequent Carb-NS isolates were Pseudomonas aeruginosa (36%), Stenotrophomonas maltophilia (29%) and Klebsiella pneumoniae (10%). Median length of hospitalisation was 34 days. Median time from index to appropriate therapy was 3 days, with empirical therapy initiated a median of 1 day before index. Carb-NS infection was believed to contribute to 21 (28%) of 76 deaths during the study. CONCLUSIONS: This study highlights the high incidence of Carb-NS GNB colonisation and infection in the UK and the need for improved management of patients with Carb-NS GNB infection.

Treatment of infections caused by multidrug-resistant Gram-negative bacteria: report of the British Society for Antimicrobial Chemotherapy/Healthcare Infection Society/British Infection Association Joint Working Party.

The Working Party makes more than 100 tabulated recommendations in antimicrobial prescribing for the treatment of infections caused by multidrug-resistant (MDR) Gram-negative bacteria (GNB) and suggest further research, and algorithms for hospital and community antimicrobial usage in urinary infection. The international definition of MDR is complex, unsatisfactory and hinders the setting and monitoring of improvement programmes. We give a new definition of multiresistance. The background information on the mechanisms, global spread and UK prevalence of antibiotic prescribing and resistance has been systematically reviewed. The treatment options available in hospitals using intravenous antibiotics and in primary care using oral agents have been reviewed, ending with a consideration of antibiotic stewardship and recommendations. The guidance has been derived from current peer-reviewed publications and expert opinion with open consultation. Methods for systematic review were NICE compliant and in accordance with the SIGN 50 Handbook; critical appraisal was applied using AGREE II. Published guidelines were used as part of the evidence base and to support expert consensus. The guidance includes recommendations for stakeholders (including prescribers) and antibiotic-specific recommendations. The clinical efficacy of different agents is critically reviewed. We found there are very few good-quality comparative randomized clinical trials to support treatment regimens, particularly for licensed older agents. Susceptibility testing of MDR GNB causing infection to guide treatment needs critical enhancements. Meropenem- or imipenem-resistant Enterobacteriaceae should have their carbapenem MICs tested urgently, and any carbapenemase class should be identified: mandatory reporting of these isolates from all anatomical sites and specimens would improve risk assessments. Broth microdilution methods should be adopted for colistin susceptibility testing. Antimicrobial stewardship programmes should be instituted in all care settings, based on resistance rates and audit of compliance with guidelines, but should be augmented by improved surveillance of outcome in Gram-negative bacteraemia, and feedback to prescribers. Local and national surveillance of antibiotic use, resistance and outcomes should be supported and antibiotic prescribing guidelines should be informed by these data. The diagnosis and treatment of both presumptive and confirmed cases of infection by GNB should be improved. This guidance, with infection control to arrest increases in MDR, should be used to improve the outcome of infections with such strains. Anticipated users include medical, scientific, nursing, antimicrobial pharmacy and paramedical staff where they can be adapted for local use.

Identification of Clostridium difficile Reservoirs in The Patient Environment and Efficacy of Aerial Hydrogen Peroxide Decontamination.

OBJECTIVE To identify, using a novel enhanced method of recovery, environmental sites where spores of Clostridium difficile persist despite cleaning and hydrogen peroxide aerial decontamination. DESIGN Cohort study. SETTING Tertiary referral center teaching hospital. METHODS In total, 16 sites representing high-frequency contact or difficult-to-clean surfaces in a single-isolation room or bed area in patient bed bays were sampled before and after terminal or hydrogen peroxide disinfection using a sponge swab. In some rooms, individual sites were not present (eg, there were no en-suite rooms in the ICU). Swab contents were homogenized, concentrated by membrane-filtration, and plated onto selective media. Results of C. difficile sampling were used to focus cleaning. RESULTS Over 1 year, 2,529 sites from 146 rooms and 44 bays were sampled. Clostridium difficile was found on 131 of 572 surfaces (22.9%) before terminal cleaning, on 105 of 959 surfaces (10.6%) after terminal cleaning, and on 43 of 967 surfaces (4.4%) after hydrogen peroxide disinfection. Clostridium difficile persisted most frequently on floor corners (97 of 334; 29.0%) after disinfection. Between the first and third quarters, we observed a significant decrease in the number of positive sites (25 of 390 vs 6 of 256). However, no similar change in the number of isolates before terminal cleaning was observed. CONCLUSION Persistence of C. difficile in the clinical environment was widespread. Although feedback of results did not improve the efficacy of manual disinfection, numbers of C. difficile following hydrogen peroxide gradually declined. Infect Control Hosp Epidemiol 2017;38:1487-1492.

Sparing carbapenem usage.

Background: Carbapenem resistance in Gram-negative bacteria is increasing in many countries and use of carbapenems and antibiotics to which resistance is linked should be reduced to slow its emergence. There are no directly equivalent antibiotics and the alternatives are less well supported by clinical trials. The few new agents are expensive. Objectives: To provide guidance on strategies to reduce carbapenem usage. Methods: A literature review was performed as described in the BSAC/HIS/BIA/IPS Joint Working Party on Multiresistant Gram-negative Infection Report. Results: Older agents remain active against some of the pathogens, although expectations of broad-spectrum cover for empirical treatment have risen. Education, expert advice on treatment and antimicrobial stewardship can produce significant reductions in use. Conclusions: More agents may need to be introduced onto the antibiotic formulary of the hospital, despite the poor quality of scientific studies in some cases.

Bacteraemia incidence, causative organisms and resistance patterns, antibiotic strategies and outcomes in a single university hospital ICU: continuing improvement between 2000 and 2013.

OBJECTIVES: The optimal duration of antibiotic treatment in patients with bloodstream infections remains contentious, with concerns regarding both undertreatment and the encouragement of antibiotic resistance. In our ICU we traditionally use short-course antibiotic monotherapy as the mainstay of treatment. We sought to document the impact of this strategy on pathogen type, resistance patterns and patient outcomes. A comparison was made against data collected during a similar exercise in 2000. METHODS: We retrospectively reviewed data on all patients with community-, hospital- and ICU-acquired bacteraemia over a 6 month period (1 December 2012 to 31 May 2013) in a general medical-surgical ICU in a London university hospital. Causative pathogens, resistance patterns, use and duration of monotherapy or combination therapy, breakthrough and relapse rates, and patient outcomes were assessed. RESULTS: The 2013 cohort comprised 113 episodes in 87 patients. Short-course monotherapy (median course 4-5 days) was used in 65.7% of episodes (73.5% in 2000). As with the 2000 cohort, the incidence of antimicrobial resistance, fungaemia, bacteraemia breakthrough and relapse remained low. Of note, there was a decreasing incidence of ICU-acquired MRSA, MDR Gram-negative bacteraemia and fluconazole-resistant candidaemia. Hospital mortality was 32% (45% in 2000). CONCLUSIONS: Our strategy predominantly utilizing short-course antibiotic monotherapy remains effective in achieving good clinical outcomes among patients with bloodstream infections, with low rates of antibiotic resistance and clinical relapse. Prospective trials of short-course monotherapy are warranted to assess clinical efficacy and antimicrobial resistance.

Staphylococcus aureus bloodstream infection: a pooled analysis of five prospective, observational studies.

OBJECTIVES: Staphylococcus aureus bacteraemia is a common, often fatal infection. Our aim was to describe how its clinical presentation varies between populations and to identify common determinants of outcome. METHODS: We conducted a pooled analysis on 3395 consecutive adult patients with S. aureus bacteraemia. Patients were enrolled between 2006 and 2011 in five prospective studies in 20 tertiary care centres in Germany, Spain, United Kingdom, and United States. RESULTS: The median age of participants was 64 years (interquartile range 50-75 years) and 63.8% were male. 25.4% of infections were associated with diabetes mellitus, 40.7% were nosocomial, 20.6% were caused by methicillin-resistant S. aureus (MRSA), although these proportions varied significantly across studies. Intravenous catheters were the commonest identified infective focus (27.7%); 8.3% had endocarditis. Crude 14 and 90-day mortality was 14.6% and 29.2%, respectively. Age, MRSA bacteraemia, nosocomial acquisition, endocarditis, and pneumonia were independently associated with death, but a strong association was with an unidentified infective focus (adjusted hazard ratio for 90-day mortality 2.92; 95% confidence interval 2.33 to 3.67, p < 0.0001). CONCLUSION: The baseline demographic and clinical features of S. aureus bacteraemia vary significantly between populations. Mortality could be reduced by assiduous MRSA control and early identification of the infective focus.

The type, level, and distribution of microorganisms within the ward environment: a zonal analysis of an intensive care unit and a gastrointestinal surgical ward.

OBJECTIVE. To investigate the distribution of hospital pathogens within general and critical care ward environments and to determine the most significant bacterial reservoirs within each ward type. DESIGN. Prospective 4-month microbiological survey. SETTING. The intensive care unit (ICU) and gastrointestinal (GI) surgical ward of a London teaching hospital. PATIENTS. Sampling was conducted in and around the bed space of 166 different patients (99 in the ICU and 67 in the GI ward). METHODS. Conventional agar contact methodology was used to sample 123 predetermined sites twice a week for 17 weeks. Sixty-one surfaces were located within the ICU, and 62 were located within the GI ward. Each surface was located within a theoretical zone of increasing distance from the patient. Aerobic colony counts were determined, and confirmatory testing was conducted on all presumptive pathogens. RESULTS. Regardless of ward type, surfaces located closest to the patient, specifically those associated with the bed (side rails, bed control, and call button), were the most heavily contaminated. Elsewhere, the type of surfaces contaminated differed with ward type. In the ICU, bacteria were most likely to be on surfaces that were regularly touched by healthcare workers (e.g., telephones and computer keyboards). In the GI ward, where the patients were mobile, the highest numbers of bacteria (including potential nosocomial pathogens) were on surfaces that were mainly touched by patients, particularly their toilet and shower facilities. CONCLUSIONS. In terms of cleaning, a hospital should not be considered a single entity. Different ward types should be treated as separate environments, and cleaning protocols should be adjusted accordingly.

The effect of glove material upon the transfer of methicillin-resistant Staphylococcus aureus to and from a gloved hand.

BACKGROUND: Although disposable gloves can protect the hands of a health care worker from acquiring bacteria, during patient care the glove surface itself can become heavily contaminated making cross transmission via contaminated gloved hands likely. The aim of this study was to determine whether the type of glove worn by health care workers could influence the spread of methicillin-resistant Staphylococcus aureus (MRSA). METHODS: Laboratory studies were conducted to assess the ease with which MRSA was transferred between different types of glove and surfaces likely to be found within the ward environment. RESULTS: In the absence of simulated body fluid, mean bacterial transfer to and from the different gloves ranged from 0.1% to 16% and from 0.01% to 19.5%, respectively. Glove material and glove hydrophobicity were identified as the 2 most important factors influencing bacterial transfer. Nitrile gloves were associated with the lowest transfer rates. The highest numbers of bacteria were transferred to and from the most hydrophilic and most hydrophobic glove, respectively. The adsorption of simulated body fluids altered the physiochemical properties of the gloves. Bacterial transfer significantly increased and was similar to and from all glove types. CONCLUSION: Disposable glove type can affect cross-contamination rates among patient, health care worker, and environment. Nonetheless, choice of glove should be considered less important than the correct use of gloves and proper hand hygiene.

Use of UV-C radiation to disinfect non-critical patient care items: a laboratory assessment of the Nanoclave Cabinet.

BACKGROUND: The near-patient environment is often heavily contaminated, yet the decontamination of near-patient surfaces and equipment is often poor. The Nanoclave Cabinet produces large amounts of ultraviolet-C (UV-C) radiation (53 W/m2) and is designed to rapidly disinfect individual items of clinical equipment. Controlled laboratory studies were conducted to assess its ability to eradicate a range of potential pathogens including Clostridium difficile spores and Adenovirus from different types of surface. METHODS: Each test surface was inoculated with known levels of vegetative bacteria (10(6) cfu/cm(2)), C. difficile spores (10(2)-10(6) cfu/cm(2)) or Adenovirus (10(9) viral genomes), placed in the Nanoclave Cabinet and exposed for up to 6 minutes to the UV-C light source. Survival of bacterial contaminants was determined via conventional cultivation techniques. Degradation of viral DNA was determined via PCR. Results were compared to the number of colonies or level of DNA recovered from non-exposed control surfaces. Experiments were repeated to incorporate organic soils and to compare the efficacy of the Nanoclave Cabinet to that of antimicrobial wipes. RESULTS: After exposing 8 common non-critical patient care items to two 30-second UV-C irradiation cycles, bacterial numbers on 40 of 51 target sites were consistently reduced to below detectable levels (≥ 4.7 log10 reduction). Bacterial load was reduced but still persisted on other sites. Objects that proved difficult to disinfect using the Nanoclave Cabinet (e.g. blood pressure cuff) were also difficult to disinfect using antimicrobial wipes. The efficacy of the Nanoclave Cabinet was not affected by the presence of organic soils. Clostridium difficile spores were more resistant to UV-C irradiation than vegetative bacteria. However, two 60-second irradiation cycles were sufficient to reduce the number of surface-associated spores from 10(3) cfu/cm(2) to below detectable levels. A 3 log10 reduction in detectable Adenovirus DNA was achieved within 3 minutes; after 6 minutes, viral DNA was undetectable. CONCLUSION: The results of this study suggest that the Nanoclave Cabinet can provide rapid and effective disinfection of some patient-related equipment. However, laboratory studies do not necessarily replicate 'in-use' conditions and further tests are required to assess the usability, acceptability and relative performance of the Nanoclave Cabinet when used in situ.

Thoracic empyema: a 12-year study from a UK tertiary cardiothoracic referral centre.

BACKGROUND: Empyema is an increasingly frequent clinical problem worldwide, and has substantial morbidity and mortality. Our objectives were to identify the clinical, surgical and microbiological features, and management outcomes, of empyema. METHODS: A retrospective observational study over 12 years (1999-2010) was carried out at The Heart Hospital, London, United Kingdom. Patients with empyema were identified by screening the hospital electronic 'Clinical Data Repository'. Demographics, clinical and microbiological characteristics, underlying risk factors, peri-operative blood tests, treatment and outcomes were identified. Univariable and multivariable statistical analyses were performed. RESULTS: Patients (n = 406) were predominantly male (74.1%); median age = 53 years (IQR = 37-69). Most empyema were community-acquired (87.4%) and right-sided (57.4%). Microbiological diagnosis was obtained in 229 (56.4%) patients, and included streptococci (16.3%), staphylococci (15.5%), gram-negative organisms (8.9%), anaerobes (5.7%), pseudomonads (4.4%) and mycobacteria (9.1%); 8.4% were polymicrobial. Most (68%) cases were managed by open thoracotomy and decortication. Video-assisted thoracoscopic surgery (VATS) reduced hospitalisation from 10 to seven days (P = 0.0005). All-cause complication rate was 25.1%, and 28 day mortality 5.7%. Predictors of early mortality included: older age (P = 0.006), major co-morbidity (P = 0.01), malnutrition (P = 0.001), elevated red cell distribution width (RDW, P<0.001) and serum alkaline phosphatase (P = 0.004), and reduced serum albumin (P = 0.01) and haemoglobin (P = 0.04). CONCLUSIONS: Empyema remains an important cause of morbidity and hospital admissions. Microbiological diagnosis was only achieved in just over 50% of cases, and tuberculosis is a notable causative organism. Treatment of empyema with VATS may reduce duration of hospital stay. Raised RDW appears to associate with early mortality.

The impact of enhanced cleaning within the intensive care unit on contamination of the near-patient environment with hospital pathogens: a randomized crossover study in critical care units in two hospitals.

OBJECTIVES: To determine the effect of enhanced cleaning of the near-patient environment on the isolation of hospital pathogens from the bed area and staff hands. DESIGN: Prospective randomized crossover study over the course of 1 yr. SETTING: Intensive care units at two teaching hospitals. PATIENTS: There were 1252 patients staying during enhanced cleaning and 1331 staying during standard cleaning. INTERVENTIONS: In each of six 2-month periods, one unit was randomly selected for additional twice-daily enhanced cleaning of hand contact surfaces. MEASUREMENTS AND MAIN RESULTS: Agar contact samples were taken at five sites around randomly selected bed areas, from staff hands, and from communal sites three times daily for 12 bed days per week. Patients admitted in the year commencing April 2007 were analyzed for hospital-acquired colonization and infection. Over the course of 1152 bed days, 20,736 samples were collected. Detection of environmental methicillin-resistant Staphylococcus aureus per bed-area day was reduced during enhanced cleaning phases from 82 of 561 (14.6%) to 51 of 559 (9.1%) (adjusted odds ratio, 0.59; 95% confidence interval, 0.40-0.86; p = .006). Other targeted pathogens (Acinetobacter baumannii, extended-spectrum ß-lactamase-producing Gram-negative bacteria, vancomycin-resistant enterococci, and Clostridium difficile) were rarely detected. Subgroup analyses showed reduced methicillin-resistant Staphylococcus aureus contamination on doctors' hands during enhanced cleaning (3 of 425; 0.7% vs. 11 of 423; 2.6%; adjusted odds ratio, 0.26; 95% confidence interval, 0.07-0.95; p = .025) and a trend to reduction on nurses' hands (16 of 1647; 1.0% vs. 28 of 1694; 1.7%; adjusted odds ratio 0.56; 95% confidence interval, 0.29-1.08; p = .077). All 1252 critical care patients staying during enhanced and 1,331 during standard cleaning were included, but no significant effect on patient methicillin-resistant Staphylococcus aureus acquisition was observed (adjusted odds ratio, 0.98; 95% confidence interval, 0.58-1.65; p = .93). CONCLUSIONS: Enhanced cleaning reduced environmental contamination and hand carriage, but no significant effect was observed on patient acquisition of methicillin-resistant Staphylococcus aureus. TRIAL REGISTRY: ISRCTN. Identifier: 06298448. http://www.controlled-trials.com/isrctn/.

Laboratory and in-use assessment of methicillin-resistant Staphylococcus aureus contamination of ergonomic computer keyboards for ward use.

BACKGROUND: An ideal computer keyboard for clinical use would be easily cleanable and cleaned by staff, meet acceptable levels of usability, and not attract hospital bacteria. METHODS: In vitro studies were performed to demonstrate bacterial transfer between keyboard surfaces and gloves. This was followed by a usability study and a controlled trial of keyboard contamination in an intensive care unit both with and without an alarm to indicate the need for cleaning. Eight cleanable keyboards were placed at random beds and compared with standard keyboards. RESULTS: Bacteria were most easily removed from a flat silicone-coated surface. The total viable count on flat keyboards with an alarm was lower than that on standard or other cleanable keyboards (median, 19 colony-forming units [cfu] (interquartile range, 7 to 40 cfu), n = 34; 65 cfu (33 to 140 cfu), n = 50; and 40 cfu (21 to 57 cfu), n = 80). Compliance with hand hygiene before touching the standard keyboard was 27%, but the alarmed keyboard was cleaned on 87% of occasions on which the alarm was triggered. The usability study found the flat profile of the cleanable keyboard did not interfere with routine use, except for touch-typing. CONCLUSION: The flat keyboard with an alarm is easy to clean, and it use is associated with better cleaning compliance.

In vitro susceptibility of Gram-positive pathogens to linezolid and teicoplanin and effect on outcome in critically ill patients.

OBJECTIVES: To determine the prevalence of teicoplanin and linezolid resistance amongst Gram-positive pathogens isolated in the intensive care unit (ICU) and the impact of any resistance on clinical outcome. METHODS: Gram-positive isolates were collected from two critical care units over 1 year. All patients were screened weekly for methicillin-resistant Staphylococcus aureus (MRSA). Susceptibility to teicoplanin and linezolid was tested by Etest. The length of hospital and critical care unit stay and the use of antibiotics in each patient were recorded. RESULTS: Reduced susceptibility to teicoplanin (MIC>or=16 mg/L) was found in 21 [3.3% (95% CI 2.0-5.0%) 6 patients] of 643 strains of MRSA versus none of 374 methicillin-susceptible S. aureus (MSSA) [<0.3% (95% CI 0-0.9%)]. Of 49 enterococci 3 were teicoplanin-resistant. All Gram-positive isolates were susceptible to linezolid. The length of treatment with teicoplanin and outcome of patients infected with these strains were similar to that of susceptible strains. MRSA was a more common cause of infection than MSSA but a less frequent colonizer. CONCLUSIONS: Resistance to teicoplanin remains at a comparatively low level and there was no clear relationship between susceptibility and outcome in this critically ill population. There was no resistance in Gram-positives to linezolid but this should be kept as a reserve antibiotic to maintain its activity.

Pharmacokinetic studies of linezolid and teicoplanin in the critically ill.

OBJECTIVES: To determine the pharmacokinetic characteristics of linezolid and teicoplanin in critically ill patients. PATIENTS AND METHODS: Serum was collected frequently during day 0 and then pre- and 1 h post-dose on days 1, 2, 3, 5, 7 and every third day thereafter during treatment. Serum linezolid concentrations were analysed using HPLC. Serum teicoplanin levels were analysed by fluorescence polarization immunoassay. RESULTS: A two-compartment model was required to characterize linezolid pharmacokinetics (n=28) and account for the accumulation seen after multiple dosing. The estimated clearance was 0.049 +/-0.016 L/h/kg (+/-s.e.m. of estimate). At steady state (dosing interval 12 h), linezolid serum concentrations exceeded the breakpoint of 4 mg/L for 10.88 h (95% CI 10.09-11.66) after a 600 mg dose with an AUC/MIC of 92.4 (95% CI 57.2-127.7). Teicoplanin was best described by a two-compartment model (n=26). The clearance was 4.97+/-1.58 L/h. Serum levels exceeded the breakpoint of 4 mg/L for the entire dosing interval in all subjects (400 mg dose every 12 h) with an AUC/MIC of 399.3 (95% CI 329.6-469.0). However, only four of 14 exceeded trough serum concentrations of 10 mg/L. For both agents, trough levels were similar in those who survived and those who died. CONCLUSIONS: Linezolid dosage at 600 mg every 12 h was adequate in the critically ill without need for adjustment for renal function. For teicoplanin, further study is needed to confirm if a trough of 10 mg/L is associated with a higher rate of cure than 5 mg/L. If so, serum drug assays would be needed to ensure a therapeutic level.

Isolation of patients in single rooms or cohorts to reduce spread of MRSA in intensive-care units: prospective two-centre study.

BACKGROUND: Hospital-acquired infection due to meticillin-resistant Staphylococcus aureus (MRSA) is common within intensive-care units. Single room or cohort isolation of infected or colonised patients is used to reduce spread, but its benefit over and above other contact precautions is not known. We aimed to assess the effectiveness of moving versus not moving infected or colonised patients in intensive-care units to prevent transmission of MRSA. METHODS: We undertook a prospective 1-year study in the intensive-care units of two teaching hospitals. Admission and weekly screens were used to ascertain the incidence of MRSA colonisation. In the middle 6 months, MRSA-positive patients were not moved to a single room or cohort nursed unless they were carrying other multiresistant or notifiable pathogens. Standard precautions were practised throughout. Hand hygiene was encouraged and compliance audited. FINDINGS: Patients' characteristics and MRSA acquisition rates were similar in the periods when patients were moved and not moved. The crude (unadjusted) Cox proportional-hazards model showed no evidence of increased transmission during the non-move phase (0.73 [95% CI 0.49-1.10], p=0.94 one-sided). There were no changes in transmission of any particular strain of MRSA nor in handwashing frequency between management phases. INTERPRETATION: Moving MRSA-positive patients into single rooms or cohorted bays does not reduce crossinfection. Because transfer and isolation of critically ill patients in single rooms carries potential risks, our findings suggest that re-evaluation of isolation policies is required in intensive-care units where MRSA is endemic, and that more effective means of preventing spread of MRSA in such settings need to be found.