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Screening and isolation for infection control

      Summary

      Control measures aimed to reduce the prevalence of healthcare-associated infections include active surveillance cultures (ASCs), contact isolation of patients colonised with epidemiologically significant pathogens, and pre-emptive isolation of high risk patients. However, the benefits of these measures are questionable. A systematic review of isolation policies demonstrated that intensive concerted interventions including isolation can substantially reduce nosocomial meticillin-resistant Staphylococcus aureus (MRSA) infection. Monitoring of interventions is fundamental. Surveillance data should be presented and fed back appropriately. International guidelines suggest that only intensive care units should apply extensive ASCs. However, legislation for mandatory screening at hospital admission has been advocated in many countries. Targeted screening could be used to limit the potential for dissemination of antibiotic-resistant pathogens from otherwise unsuspected carriers from the start of patients' hospitalisation, as opposed to other strategies, in which screening programmes target patients already hospitalised. Although the influx of antibiotic-resistant pathogens into the hospital would not change, early detection would reduce the time colonised patients might have to disseminate pathogens. Recently, rapid methods for molecular detection of MRSA have been developed. Data on the impact of these tests on the MRSA acquisition rate are extremely heterogeneous. Published studies differ according to the settings in which they have been evaluated, the choice of patient population to be screened, other infection control measures employed and, most importantly, study design and baseline prevalence of MRSA. Based on these studies, definitive recommendations cannot be made.

      Keywords

      Introduction

      Efforts to control healthcare-associated infections (HCAIs) have, with few exceptions, failed, resulting in growing political and public alarm. Increased morbidity and mortality due to antibiotic-resistant bacteria acquired during hospital stay have also been reported worldwide.
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      • Corey G.R.
      Epidemiology of methicillin-resistant Staphylococcus aureus.
      • Harris A.D.
      • McGregor J.C.
      • Furuno J.P.
      What infection control interventions should be undertaken to control multidrug-resistant Gram-negative bacteria?.
      The European Centre for Disease Prevention and Control has estimated that HCAIs affect about one in 20 hospital patients.
      • Anonymous
      Healthcare-associated infections. European Centre for Disease Prevention and Control.
      In January 2009 the European Commission published a Council Recommendation on patient safety, including the prevention and control of HCAIs.

      Proposal for a Council Recommendation on patient safety, including the prevention and control of healthcare associated infections {COM(2008) 836 final} {SEC(2008) 3004} {SEC(2008) 3005}. EC Brussels; 20 January 2009.

      The Commission advised that a national strategy, complementary to strategies targeted towards the prudent use of antimicrobial agents, should be developed incorporating prevention and control of HCAIs into national public health objectives and aiming to reduce the risk of such infections within hospitals. Hence, the question arises: how are public health professionals to decide what is the most cost-effective approach to preventing HCAIs? Unfortunately, a satisfactory answer from evidence-based data cannot be provided. Up to now, most studies have focused on meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) and to a much lesser extent on multidrug-resistant (MDR) Gram-negative bacteria. The control measures aimed to reduce the spread of HCAIs include: education of healthcare workers (HCWs) with implementation and observation of hand-washing practices; active surveillance cultures (ASCs); contact isolation of patients colonised with epidemiologically important bacteria (such as MRSA and VRE); pre-emptive isolation of high risk patients; and restriction of antibiotic use. Numerous studies have demonstrated that the best way to face the problem is a multidisciplinary approach. Marshall et al. summarised in four steps the actions needed to reduce the prevalence of HCAIs: (1) antibiotic stewardship; (2) reduction in the number of colonised patients; (3) prevention of infection in colonised patients; and (4) prevention of cross-transmission between hospitalised patients.
      • Marshall C.
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      • Spelman D.
      Control of endemic MRSA – what is the evidence? A personal view.
      Among the strategies aimed to reduce patient-to-patient transmission, the role of screening and isolation is still under debate.
      The first assumption underlying a screening strategy is that colonisation increases the risk of infection. Huang et al. observed that MRSA infections developed in 29% of 209 colonised patients in an 18 month follow-up period.
      • Huang S.S.
      • Platt R.
      Risk of methicillin-resistant Staphylococcus aureus infection after previous infection or colonization.
      Twenty-eight percent of infections involved bacteraemia and 56% involved pneumonia, soft tissue infection, osteomyelitis, or septic arthritis. A systematic review including ten studies and 1170 patients estimated the risk of infection following MRSA colonisation.
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      The risk of infection after nasal colonisation with Staphylococcus aureus.
      The analysis showed a four-fold increase (95% confidence interval: 2–7) in the risk of infection after MRSA colonisation compared with meticillin-susceptible S. aureus (MSSA) colonisation. Significant heterogeneity was detected between studies. The majority of reports differed in the choice of patient population, severity of illness, and frequency of sampling employed to detect colonisation, further suggesting the need for new research with appropriate statistical analysis. Olivier et al. studied the risk of VRE bacteraemia among patients previously colonised with the bacteria. Four percent of colonised patients developed bacteraemia caused by the same strain, as confirmed by the genotypic analysis.
      • Olivier C.N.
      • Blake R.K.
      • Steed L.L.
      • Salgado C.D.
      Risk of vancomycin-resistant enterococcus (VRE) bloodstream infection among patients colonized with VRE.
      Important clues in deciding whether screening and contact isolation are needed are the proportions of antibiotic resistance attributable to hospital antibiotic use and cross-transmission in hospitalised patients. In a multicentre prospective Italian study, we determined the incidence of new colonisation due to MRSA, VRE and ciprofloxacin-resistant Pseudomonas aeruginosa per 1000 days of antibiotic therapy.
      • Tacconelli E.
      • De Angelis G.
      • Cataldo M.A.
      • et al.
      Usage of carbapenems significantly increases the rate of new colonisation due to antibiotic-resistant bacteria in hospitalised patients.
      The highest risk was associated with carbapenem use, with eight new cases of MRSA colonisation per 1000 days of therapy. An accurate estimate of the attributable fraction of antibiotic resistance due to cross-transmission is not available. Many factors have contributed to this lack of information. For example, Buke et al. demonstrated significant epidemiological differences in the variables associated with colonisation with MRSA and extended spectrum β-lactamase-producing (ESBL) Gram-negative bacteria.
      • Buke C.
      • Armand-Lefevre L.
      • Lolom I.
      • et al.
      Epidemiology of multidrug-resistant bacteria in patients with long hospital stays.
      Another parameter useful for a better understanding of the attributable fraction due to cross-transmission is colonisation pressure, i.e. the prevalence of resistance in the surrounding environment. Williams et al. demonstrated that ongoing monitoring of colonisation pressure provides the opportunity for early implementation of enhanced infection prevention and control practices, and can potentially decrease nosocomial transmission of MRSA and prevent outbreaks.
      • Williams V.R.
      • Callery S.
      • Vearncombe M.
      • Simor A.E.
      The role of colonization pressure in nosocomial transmission of methicillin-resistant Staphylococcus aureus.

      Should mandatory screening for MRSA and VRE be performed?

      ‘Who’ should be screened for epidemiologically important pathogens and ‘where’ and ‘when’ are still open questions. In studies of infection control measures, screening is never the primary intervention and it is usually included in a multifaceted approach. The majority of studies relate to hospital-acquired MRSA (HA-MRSA). A recent systematic review of the literature performed by McGinigle et al. summarised the evidence of the efficacy of ASCs in the intensive care unit (ICU) setting on several clinical and economic outcomes.
      • McGinigle K.L.
      • Gourlay M.L.
      • Buchanan I.B.
      The use of active surveillance cultures in adult intensive care units to reduce methicillin-resistant Staphylococcus aureus-related morbidity, mortality, and costs: a systematic review.
      Although most of observation-based studies reported a significant reduction in MRSA infection after the application of ASCs, the evidence was of poor quality and could not allow definitive recommendations. The role of ASCs might be different according to the baseline prevalence of MRSA and the hospital setting. In three intensive care units (ICUs) in France the acquisition of MRSA was reduced from 7% to 3% through multiple interventions, including ASC, contact precautions and use of alcohol hand rub.
      • Lucet J.C.
      • Paoletti X.
      • Lolom I.
      • et al.
      Successful long-term program for controlling methicillin-resistant Staphylococcus aureus in intensive care units.
      All patients were screened for nasal carriage on hospital admission and weekly thereafter and placed under contact precautions if screen positive. Similar results were obtained in a 18 month study in Colorado, USA.
      • Clancy M.
      • Graepler A.
      • Wilson M.
      • Douglas I.
      • Johnson J.
      • Price C.S.
      Active screening in high-risk units is an effective and cost-avoidant method to reduce the rate of methicillin-resistant Staphylococcus aureus infection in the hospital.
      All patients admitted to ICUs and medical wards were screened at admission and weekly thereafter. The overall rate of HA-MRSA infections compared with historical controls decreased significantly, although an increased number of community-acquired MRSA skin infections was admitted to the wards. The majority occurred in surgery ICU (SICU) because the medical ICU (MICU) had a higher incidence of colonisation and lower percentage of compliance with hand washing. Physicians in SICU were also less likely to enter isolation rooms.
      Some countries have maintained low endemic levels of MRSA by implementing nationwide control measures targeting MRSA such as the ‘search and destroy’ (S&D) strategy.
      • Vos M.C.
      • Ott A.
      • Verbrugh H.A.
      Successful search-and-destroy policy for methicillin-resistant Staphylococcus aureus in The Netherlands.
      Measures of S&D include: contact isolation for MRSA-positive patients; pre-emptive isolation and screening for high risk patients; screening of patients and personnel following an unexpected case of MRSA; screening of HCWs with furlough of those found to be carriers until decontamination is achieved; closure of wards to new admissions if there is more than one carrier among hospitalised patients. Interestingly, Bootsma et al. generated a stochastic three-hospital model and an analytical one-hospital model to quantify the effectiveness of different infection control measures and to predict the effect of rapid diagnostic testing on isolation needs.
      • Bootsma M.C.
      • Diekmann O.
      • Bonten M.J.
      Controlling methicillin-resistant Staphylococcus aureus: quantifying the effects of interventions and rapid diagnostic testing.
      The analysis showed that the application of the S&D strategy in a hospital with high endemicity would reduce the prevalence to <1% within 6 years.
      The costs of a hospital-wide selective screening programme were analysed for a 19 month period in a 700-bed hospital with 23 000 admissions annually in Germany.
      • Wernitz M.H.
      • Keck S.
      • Swidsinski S.
      • Schulz S.
      • Veit S.K.
      Cost analysis of a hospital-wide selective screening programme for methicillin-resistant Staphylococcus aureus (MRSA) carriers in the context of diagnosis related groups (DRG) payment.
      The screening programme was able to prevent 48% of predicted nosocomial MRSA, saving a predicted €200,782 with a net saving of €110,000 annually. The screening programme became cost-effective at a low MRSA incidence rate. The major limit of the study was that the authors did not use real costs calculation but instead hospital reimbursement as a surrogate parameter.
      For VRE control, it has been estimated that ASCs would be cost-beneficial for hospital units where the number of patients with VRE bacteraemia is at least 6–9 patients per year or if the savings from fewer VRE bacteraemic patients in combination with decreased antimicrobial use ranged from US$100,000 to 150,000 per year.
      • Montecalvo M.A.
      • Jarvis W.R.
      • Uman J.
      • et al.
      Costs and savings associated with infection control measures that reduced transmission of vancomycin-resistant enterococci in an endemic setting.
      Targeted surveillance based on patients' risk factors in medical or surgical wards might be preferred as the most effective use of hospital resources. Risk factors for HCAIs due to MRSA at hospital admissions were analysed in 127 patients with bacteraemia in an endemic setting in Boston, USA.
      • Tacconelli E.
      • Venkataraman L.
      • De Girolami P.C.
      • D'Agata E.M.
      Methicillin-resistant Staphylococcus aureus bacteraemia diagnosed at hospital admission: distinguishing between community-acquired versus healthcare-associated strains.
      Two logistic regression models were generated. In the first model, previous MRSA infection or colonisation, cellulitis, presence of a central venous catheter (CVC), and skin ulcers were independently associated with MRSA bacteraemia. Since prior MRSA colonisation or infection status may not be known at the time of hospitalisation, a second model was generated which excluded prior history of MRSA colonisation or infection. This model identified the presence of a CVC, hospitalisation(s) within the previous six months, use of quinolones within the previous 30 days, and diabetes mellitus as independent risk factors for MRSA bacteraemia. Both models had high sensitivity and specificity. Harbarth et al. defined risk factors for unknown carriage of MRSA at hospital admission in a university hospital in Geneva.
      • Harbarth S.
      • Sax H.
      • Fankhauser-Rodriguez C.
      • Schrenzel J.
      • Agostinho A.
      • Pittet D.
      Evaluating the probability of previously unknown carriage of MRSA at hospital admission.
      Male sex, age >75 years, previous exposure to quinolones, cephalosporins and carbapenems, previous hospitalisation, intrahospital transfer and urinary catheterisation were associated with MRSA colonisation at hospital admission.
      A prediction score for VRE identification was derived and validated in a high-endemic setting in the USA.
      • Tacconelli E.
      • Karchmer A.W.
      • Yokoe D.
      • D'Agata E.M.
      Preventing the influx of vancomycin-resistant enterococci into health care institutions, by use of a simple validated prediction rule.
      A risk index was derived by using six independent risk factors associated with VRE recovery within 48 h of hospital admission: previous isolation of MRSA (4 points), whether the patient was receiving long-term haemodialysis (3), transfer from a long-term care facility (3), antibiotic exposure (3), prior hospitalisation (3), and age >60 years (2). On the basis of a point score ≥10, the sensitivity, specificity, and positive and negative predictive values of this prediction rule were 44%, 98%, 81%, and 90%, respectively.
      For several years conventional culture methods, which can take ≥48–72 h to obtain a result, have been considered the gold standard to detect MRSA colonisation. In the absence of pre-emptive room isolation this time might be enough to spread the bacterium among patients. Recently, rapid methods for molecular detection of MRSA-colonised patients with available results in 2 h have been developed with high sensitivity and specificity.
      • Carroll M.C.
      Rapid diagnostics for methicillin-resistant Staphylococcus aureus: current status.
      Major limits for the wide application of molecular diagnosis for MRSA are related to the high costs and varying benefits in different studies. Nine studies (eight cohort studies and one cluster-randomised, cross-over trial) analysed the efficacy of screening for MRSA using molecular tests compared with no screening or screening with conventional cultures.
      • Conterno L.O.
      • Shymanski J.
      • Ramotar K.
      • et al.
      Real-time polymerase chain reaction detection of methicillin-resistant Staphylococcus aureus: impact on nosocomial transmission and costs.
      • Cunningham R.
      • Jenks P.
      • Northwood J.
      • Wallis M.
      • Ferguson S.
      • Hunt S.
      Effect on MRSA transmission of rapid PCR testing of patients admitted to critical care.
      • Harbarth S.
      • Masuet-Aumatell C.
      • Schrenzel J.
      • et al.
      Evaluation of rapid screening and pre-emptive contact isolation for detecting and controlling methicillin-resistant Staphylococcus aureus in critical care: an interventional cohort study.
      • Jeyaratnam D.
      • Whitty C.J.
      • Phillips K.
      • et al.
      Impact of rapid screening tests on acquisition of meticillin resistant Staphylococcus aureus: cluster randomised crossover trial.
      • Jog S.
      • Cunningham R.
      • Cooper S.
      • et al.
      Impact of reoperative screening for meticillin-resistant Staphylococcus aureus by real-time polymerase chain reaction in patients undergoing cardiac surgery.
      • Keshtgar M.R.
      • Khalili A.
      • Coen P.G.
      • et al.
      Impact of rapid molecular screening for meticillin-resistant Staphylococcus aureus in surgical wards.
      • Robicsek A.
      • Beaumont J.L.
      • Paule S.M.
      • et al.
      Universal surveillance for methicillin-resistant Staphylococcus aureus in 3 affiliated hospitals.
      • Harbarth S.
      • Fankhauser C.
      • Schrenzel J.
      • et al.
      Universal screening for methicillin-resistant Staphylococcus aureus at hospital admission and nosocomial infection in surgical patients.
      Studies were performed in different settings: ICUs (two studies), medical and/or surgery wards (four) and throughout the hospital (two). Four papers reported a significant decrease in the rate of HA-MRSA, two observed no effects, and one showed uncertain results. Variability in the efficacy of polymerase chain reaction (PCR) might be partially explained by different comparisons applied in the studies. The main limitations other than the study design were systematic screening not performed at discharge, PCR result not confirmed by conventional culture, lack of analysis of possible variation in MRSA epidemiology during the study period, absence of monitoring of compliance with decolonisation treatment or contact precautions. Based on these studies, definitive recommendations cannot be made.
      A rapid real-time PCR test that detects the presence of vanA and/or vanB genes has been proposed for rapid screening to identify patients harbouring VRE at hospital admission.
      • Stamper P.D.
      • Cai M.
      • Lema C.
      • Eskey K.
      • Carroll K.C.
      Comparison of the BD GeneOhm VanR assay to culture for identification of vancomycin-resistant enterococci in rectal and stool specimens.
      For 502 rectal swabs and stool specimens, sensitivity and specificity was 98% and 87%, and 95% and 87%, respectively. When the test is used in settings with high prevalence of vanA isolates, results would not require conventional culture confirmation. On the contrary, the high number of false positives for vanB would require culture confirmation.
      In the USA, several large organisations such as the Veterans Affairs and Evanston Northwestern University and a few states such as Illinois, New Jersey and Pennsylvania introduced mandatory screening for both VRE and MRSA. In the UK it was announced in October 2007 that all patients admitted to National Health Service hospitals would be screened for carriage of MRSA. Screening was to be in place for all elective admissions by March 2009 and for all admissions by March 2011. This extended the guidance issued as part of the ‘Saving Lives’ package in September 2006, which recommended a risk-based approach to screening to include high-risk surgical patients, renal dialysis patients, those admitted to ICUs, high risk medical admissions, and transfers from other hospitals, long-term care facilities, and nursing homes. In response to new legislation, the Society for Healthcare Epidemiology of America (SHEA) and the Association for Professionals in Infection Control and Epidemiology Inc. (APIC) developed a position statement asserting that, although conspicuous evidence to support the use of ASCs for high risk patients and during outbreaks is available, there is not sufficient evidence to justify the mandatory use of this control measure.
      • Weber S.G.
      • Huang S.S.
      • Oriola S.
      • et al.
      Legislative mandates for use of active surveillance cultures to screen for meticillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci: position statement from the Joint SHEA and APIC Task Force.
      The lack of support for legislation is due to the uncertainties and the potential unintended consequences of legislation mandating application of ASCs, namely: exclusion of local infection control professionals from their role of leading risk assessment and resource allocation; unresolved controversies regarding the epidemiological, biological and clinical implications of ASCs; and the potentially negative effects on patients of contact isolation.

      Should contact isolation precautions be implemented for patients colonised or infected with epidemiologically important bacteria?

      Sixty-five percent of HCWs contaminate their uniforms or gowns during routine care of patients with MRSA. On >25% of occasions HCW's clean hands became recontaminated after contact with their contaminated clothing. Cooper et al. demonstrated that intensive concerted interventions, including isolation, can substantially reduce MRSA.
      • Cooper B.S.
      • Stone S.P.
      • Kibbler C.C.
      • et al.
      Isolation measures in the hospital management of methicillin resistant Staphylococcus aureus (MRSA): systematic review of the literature.
      A before-and-after study evaluated the efficacy of contact and droplet precautions in reducing the incidence of HA-MRSA infections.
      • Mangini E.
      • Segal-Maurer S.
      • Burns J.
      • et al.
      Impact of contact and droplet precautions on the incidence of hospital-acquired methicillin-resistant Staphylococcus aureus infection.
      After a baseline period, contact and droplet precautions were implemented in all ICUs. Reductions in the incidence of HA-MRSA infection in ICUs also led to the implementation of contact precautions in non-ICU patient care areas. Combined rates of HA-MRSA infection in the MICU and SICU decreased with no significant change in other ICUs. After the discontinuation of droplet precautions, the combined rate in the MICU and SICU decreased further although not significantly. After the implementation of contact precautions the rate decreased significantly in non-ICU areas.
      Although >100 studies have reported control of MRSA with screening linked to isolation and cohorting, two studies suggested that reporting culture results and isolating colonised patients had no impact on the prevalence of HA-MRSA.
      • Cepeda J.A.
      • Whitehouse T.
      • Cooper B.
      • et al.
      Isolation of patients in single rooms or cohorts to reduce spread of MRSA in intensive-care units: prospective two-centre study.
      The first study assessed the effect of daily microbiological surveillance alone on the spread of S. aureus.
      • Nijssen S.
      • Bonten M.J.
      • Weinstein R.A.
      Are active microbiological surveillance and subsequent isolation needed to prevent the spread of methicillin-resistant Staphylococcus aureus?.
      During a 10 week period, surveillance cultures were performed in 158 patients. Surveillance cultures and genotyping of MRSA and MSSA isolates demonstrated the absence of cross-transmission among patients. The second study was a prospective one-year study in the ICUs of two teaching hospitals. Admission and weekly screens were used to ascertain the incidence of MRSA colonisation.
      • Farr B.M.
      What to think if the results of the National Institutes of Health randomized trial of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus control measures are negative (and other advice to young epidemiologists): a review and an au revoir.
      In the middle six months, MRSA-positive patients were neither moved to a single room nor cohort-nursed unless they were carrying other multiresistant bacteria. 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. However, the studies have many limitations. First, the time elapsed from admission to the results of cultures was up to four days, and patients with a length of hospitalisation <48 h were excluded. This time would have been sufficient, especially in highly endemic situations, to allow person-to-person transmission of MRSA. Second, the low number of carers and patients might have had an important role on the final outcome.
      For VRE the role of contact precautions is still under evaluation. Our group is currently reviewing the available evidence within the Cochrane Wound Group.
      • Tacconelli E.
      • Cauda R.
      • Cataldo M.A.A.
      • Carmeli Y.
      • De Angelis G.
      Control interventions for preventing spread of vancomycin-resistant enterococci (VRE) in hospitals.
      Many reports showed that intensive infection control strategies including isolation enabled the timely termination of VRE outbreaks, even those involving VRE strains with high epidemic potential on high risk wards. Premature discontinuation of infection control measures caused recurrence of VRE transmission.
      • Schmidt-Hieber M.
      • Blau I.W.
      • Schwartz S.
      • et al.
      Intensified strategies to control vancomycin-resistant enterococci in immunocompromised patients.
      A combination of control measures including ASCs, contact precautions for all colonised and infected patients and antimicrobial stewardship has also been reported to significantly reduce the incidence of ESBL-producing bacteria.
      • Conterno L.O.
      • Shymanski J.
      • Ramotar K.
      • Toye B.
      • Zvonar R.
      • Roth V.
      Impact and cost of infection control measures to reduce nosocomial transmission of extended-spectrum beta-lactamase-producing organisms in a non-outbreak setting.
      Contact precautions have been associated with several adverse effects. Their application should be preceded by accurate training of HCWs and it should not be accepted as a substitute for hand washing. In the MICU at Duke University Medical Center it was observed that HCWs were approximately half as likely to enter the rooms of patients in contact isolation.
      • Kirkland K.B.
      • Weinstein J.M.
      Adverse effects of contact isolation.
      The results supported suggestions made by other studies that patients in isolation receive less frequent care and may even suffer psychologically.

      Decolonisation

      Following positive screening, a patient should be placed in contact precaution and decolonised. The majority of protocols for MRSA decolonisation include mupirocin alone or in combination with body washes, and systemic therapy with one or two antibiotics such as rifampicin, doxycycline and trimethoprim-sulfamethoxazole. Less popular protocols include the tea tree oil, a popular natural antiseptic, topical gentian violet and arbekacin inhalation in patients with percutaneous endoscopic gastrostomy. The duration of the decolonisation treatment is usually 7–10 days. Decolonisation has been proven to be efficacious in reducing infections in high risk groups.
      • Kallen A.J.
      • Wilson C.T.
      • Larson R.J.
      Perioperative intranasal mupirocin for the prevention of surgical-site infections: systematic review of the literature and meta-analysis.
      In dialysis patients the use of mupirocin reduced the rate of S. aureus infections by 68%.
      • Tacconelli E.
      • Carmeli Y.
      • Aizer A.
      • Ferreira G.
      • Foreman M.G.
      • D'Agata E.M.
      Mupirocin prophylaxis to prevent Staphylococcus aureus infection in patients undergoing dialysis: a meta-analysis.
      Risk reduction was higher in peritoneal dialysis patients. Significant reduction of S. aureus infections was also observed in patients after cardiothoracic and orthopaedic surgery.
      • Kallen A.J.
      • Wilson C.T.
      • Larson R.J.
      Perioperative intranasal mupirocin for the prevention of surgical-site infections: systematic review of the literature and meta-analysis.
      Different protocols were used for VRE decolonisation with poor response. After one month >50% of the patients are recolonised.
      • Wong M.T.
      • Kauffman C.A.
      • Standiford H.C.
      • et al.
      Ramoplanin VRE2 Clinical Study Group. Effective suppression of vancomycin-resistant Enterococcus species in asymptomatic gastrointestinal carriers by a novel glycolipodepsipeptide, ramoplanin.
      The most promising agent for gastrointestinal decolonisation was ramoplanin, the first of a new class of antibiotics, the glycolipodepsipeptides. The drug is bactericidal against Gram-positive bacteria and is not absorbed when taken orally and thus achieves high faecal concentrations. In animal studies ramoplanin inhibits VRE colonisation due to re-expansion of the colonic microflora. A randomised placebo-controlled double-blind trial showed that VRE decolonisation was unsuccessful in 79% of the patients.
      • Wong M.T.
      • Kauffman C.A.
      • Standiford H.C.
      • et al.
      Ramoplanin VRE2 Clinical Study Group. Effective suppression of vancomycin-resistant Enterococcus species in asymptomatic gastrointestinal carriers by a novel glycolipodepsipeptide, ramoplanin.
      Screening and decolonisation of HCWs has been attempted for MRSA but its use remains controversial.
      • Simpson A.H.
      • Dave J.
      • Cookson B.
      The value of routine screening of staff for MRSA.
      The prevalence of MRSA among professionals is related to geographical regions (Eastern Europe 1.6%, Africa 15.5%), location (ICU 4.7%, general wards 6.3%), type of HCW (nurse 8%, medical 7.4%), type of room (private cohorting 2.4%, no private/no cohorting 7.7%), and contact precautions in force (3.3%) or not applied (5.6%).
      • Albrich W.C.
      • Harbarth S.
      Health-care workers: source, vector, or victim of MRSA?.
      However, little evidence suggests that the exclusion of MRSA-positive HCWs improves the control of HA-MRSA with the exception of hospital outbreaks. Screening might have psychological implications for professionals who test positive. Cost-effectiveness analysis for this approach in this population is also unavailable. Only staff members with colonised or infected hand lesions should be off work while receiving courses of clearance therapy.
      • Nathwani D.
      • Morgan M.
      • Masterton R.G.
      • et al.
      British Society for Antimicrobial Chemotherapy Working Party on community-onset MRSA Infections. Guidelines for UK practice for the diagnosis and management of meticillin-resistant Staphylococcus aureus (MRSA) infections presenting in the community.

      Discussion

      Patients and the public increasingly view rates of HCAIs as indicators of quality of patient care. There has been much debate about the evidence and cost-effectiveness of various infection control policies. A multidisciplinary approach should be employed in all settings including: hand hygiene programmes, ASCs, training and feedback to HCWs, bundles for ventilator-associated pneumonia and CVC-related infections and environmental programmes. Target pathogens should be locally defined. Programmes focused solely on MRSA might not be the appropriate answer to impact on HCAIs. Intensive promotion of alcohol-based hand rubs and behavioural change interventions might represent a more cost-effective approach compared with universal screening policies. On the grounds of lack of evidence-based clinical and cost-effectiveness data, routine screening of all admissions to hospital is not advocated at this time.
      • Diekema D.J.
      • Climo M.
      Preventing MRSA infections: finding it is not enough.
      • Gould I.M.
      Control of methicillin-resistant Staphylococcus aureus in the UK.
      • Dancer S.J.
      Considering the introduction of universal MRSA screening.
      • Tacconelli E.
      Methicillin-resistant Staphylococcus aureus: risk assessment and infection control policies.
      Rapid molecular tests for MRSA screening are realistic only when combined with adequate infection control measures in high risk patients.

      Conflict of interest statement

      None.

      Funding sources

      None.

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