Effectiveness of preemptive barrier precautions in controlling nosocomial colonization and infection by methicillin-resistant Staphylococcus aureus in a burn unit

Impact of the "Zero Resistance" program on acquisition of multidrug-resistant bacteria in patients admitted to Intensive Care Units in Spain. A prospective, intervention, multimodal, multicenter study

OBJECTIVE

To assess the impact of a multimodal interventional project ("Zero Resistance") on the acquisition of multidrug-resistant bacteria (MDR-B) during the patient's ICU stay.

DESIGN

Prospective, open-label, interventional, multicenter study.

SETTING

103 ICUs.

PATIENTS

Critically ill patients admitted to the ICUs over a 27-month period.

INTERVENTIONS

Implementation of a bundle of 10 recommendations to prevent emergence and spread of MDR-B in the ICU.

MAIN VARIABLE OF INTEREST

Rate of patients acquiring MDR-B during their ICU stay, with differentiation between colonization and infection.

RESULTS

A total of 139,505 patients were included. In 5409 (3.9%) patients, 6020 MDR-B on ICU admission were identified, and in 3648 (2.6%) patients, 4269 new MDR-B during ICU stay were isolated. The rate of patients with MDR-B detected on admission increased significantly (IRR 1.43, 95% CI 1.31-1.56) (p<0.001) during the study period, with an increase of 32.2% between the initial and final monthly rates. On the contrary, the rate of patients with MDR-B during ICU stay decreased non-significantly (IRR 0.93, 95% CI 0.83-1.03) (p=0.174), with a 24.9% decrease between initial and final monthly rates. According to the classification into colonization or infection, there was a highly significant increase of MDR-B colonizations detected on admission (IRR 1.69, 95% CI 1.52-1.83; p<0.0001) and a very significant decrease of MDR-B-infections during ICU stay (IRR 0.67, 95% CI 0.57-0.80, p<0.0001).

CONCLUSIONS

The implementation of ZR project-recommendations was associated with a significantly reduction an infection produced by MDR-B acquired during the patient's ICU stay.

Efficacy of Infection Control Measures in Managing Outbreaks of Multidrug-Resistant Organisms in Burn Units

BACKGROUND

Multidrug-resistant organisms (MDROs) pose a significant threat to severe burn victims and represents a clear epidemic hazard in burn units. Several infection control measures have been implemented to control and manage the outbreaks of MDRO. The efficiency of those measures, however, remains controversial and an area of debate. A systematic review was conducted to evaluate the efficacy of infection control measures and the necessity of closing burn units in dealing with MDRO outbreaks.

METHODS

Peer-reviewed articles were identified using PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases, focusing on infection control measures to manage MDRO outbreaks in burn units.

RESULTS

Twenty-one studies that reported MDRO outbreaks in burn units met the inclusion criteria. The outbreaks were successfully controlled with interventions in 17 units (81%), partially controlled in 1 unit (4.7%), and uncontrolled in 3 units (14.3%). Infection control measures were implemented by screening patient (19 units), screening health care worker (17 units), obtaining environmental cultures (16 units), providing ongoing staff education (13 units), cohort or isolation (17 units), preemptive barrier precautions (10 units), improving hand hygiene (15 units), and enhanced cleaning and environmental disinfection (17 units). Closure of burn units occurred in 8 units, with outbreaks controlled in 6 of the units (75%). The reasons for unit closure include decontamination (4 units; 50%), outbreak investigation (1 unit; 12.5%), and uncontrolled outbreaks (3 units; 37.5%). The incidence of infection was significantly decreased in 4 units after the closure but rose again after reopening in 1 of the units. In 3 units, the spread was halted by other control measures, including change of hydrotherapy facilities, identification of staff transmission, and unit structure remodeling.

CONCLUSIONS

Proper infection control measures play an important role in managing MDRO outbreaks in burn units. Temporary closure of burn units may be necessary to control the spread of nosocomial, and this option should be considered when other measures are ineffective.

Strategies to Prevent Healthcare-Associated Infections: A Narrative Overview

Healthcare-associated infections (HCAIs) are a major source of morbidity and mortality and are the second most prevalent cause of death. Furthermore, it has been reported that for every one-hundred patients admitted to hospital, seven patients in high-income economies and ten in emerging and low-income economies acquire at least one type of HCAI. Currently, almost all pathogenic microorganisms have developed antimicrobial resistance, and few new antimicrobials are being developed and brought to market. The literature search for this narrative review was performed by searching bibliographic databases (including Google Scholar and PubMed) using the search terms: "Strategies," "Prevention," and "Healthcare-Associated Infections," followed by snowballing references cited by critical articles. We found that although hand hygiene is a centuries-old concept, it is still the primary strategy used around the world to prevent HCAIs. It forms one of a bundle of approaches used to clean and maintain a safe hospital environment and to stop the transmission of contagious and infectious microorganisms, including multidrug-resistant microbes. Finally, antibiotic stewardship also has a crucial role in reducing the impact of HCAIs through conserving currently available antimicrobials.

Acute Respiratory Distress Syndrome From an Infectious Disease Perspective

Acute respiratory distress syndrome (ARDS) is an inflammatory form of lung injury in response to various clinical entities or inciting events, quite frequently due to an underlying infection. Morbidity and mortality associated with ARDS are significant. Hence, early recognition and targeted treatment are crucial to improve clinical outcomes. This article encompasses the most common infectious etiologies of ARDS and their clinical presentations and management, along with commonly encountered infectious complications in such patients.

Noninfectious Hospital Adverse Events Decline After Elimination of Contact Precautions for MRSA and VRE

OBJECTIVETo evaluate the impact of discontinuing routine contact precautions (CP) for endemic methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) on hospital adverse events.DESIGNRetrospective, nonrandomized, observational, quasi-experimental study.SETTINGAcademic medical center with single-occupancy rooms.PARTICIPANTSInpatients.METHODSWe compared hospital reportable adverse events 1 year before and 1 year after discontinuation of routine CP for endemic MRSA and VRE (preintervention and postintervention periods, respectively). Throughout the preintervention period, daily chlorhexidine gluconate bathing was expanded to nearly all inpatients. Chart reviews were performed to identify which patients and events were associated with CP for MRSA/VRE in the preintervention period as well as the patients that would have met prior criteria for MRSA/VRE CP but were not isolated in the postintervention period. Adverse events during the 2 periods were compared using segmented and mixed-effects Poisson regression models.RESULTSThere were 24,732 admissions in the preintervention period and 25,536 in the postintervention period. Noninfectious adverse events (ie, postoperative respiratory failure, hemorrhage/hematoma, thrombosis, wound dehiscence, pressure ulcers, and falls or trauma) decreased by 19% (12.3 to 10.0 per 1,000 admissions, P=.022) from the preintervention to the postintervention period. There was no significant difference in the rate of infectious adverse events after CP discontinuation (20.7 to 19.4 per 1,000 admissions, P=.33). Patients with MRSA/VRE showed the largest reduction in noninfectious adverse events after CP discontinuation, with a 72% reduction (21.4 to 6.08 per 1,000 MRSA/VRE admissions; P<.001).CONCLUSIONAfter discontinuing routine CP for endemic MRSA/VRE, the rate of noninfectious adverse events declined, especially in patients who no longer required isolation. This suggests that elimination of CP may substantially reduce noninfectious adverse events.Infect Control Hosp Epidemiol 2018;788-796.

Intravascular Catheters and Biofilm Control

Intravascular catheters are the most common cause of nosocomially acquired bloodstream infections. Bacteria found adhering to the intraluminal surfaces of catheters are the principal source and cause of these infections. Adherent bacteria overtime are known to form multicellular communities which become encased within a three dimensional matrix of extracellular polymeric material known as biofilms, which are thought to be responsible for persistent infections. Consequently, a number of technologies have been developed to help prevent and control biofilms in intravascular catheters. One such approach involves impregnating catheter material with antimicrobial agents. Unfortunately these methods are not universally effective in preventing catheter-related biofilm infections. Technologies that utilise antimicrobials, as catheter locks have been shown to have more potential for preventing biofilm formation and reducing the incidences of catheter related bloodstream infections (CRBSI). This article discusses the significance of biofilms in intravascular catheters and determines whether the treatments available today are proving to be effective for controlling biofilms and draws attention to future avenues which are being investigated to control biofilms and therefore CRBSI.

Multidrug-Resistant Bacterial Outbreaks in Burn Units: A Synthesis of the Literature According to the ORION Statement

The objective of this study is to review the literature on multidrug-resistant bacteria (MDRB) outbreaks in burn units according to the outbreak reports and intervention studies of nosocomial infection statement. A PubMed search engine was enlisted to identify reports, in English and French, on MDRB outbreaks in burn units, with no date restrictions, using the following key words: ("burn" OR "burns" OR "severe burn") AND ("unit" OR "critical care" OR "acute care" OR "intensive care" OR "center" OR "centre" OR "department") AND ("outbreak" OR "epidemic") AND ("resistant" OR "multidrug-resistant" OR "resistance" OR "MDR" OR "MDRO"). Twenty-nine articles on such outbreaks in burn units were analyzed. A wide variety of these outbreaks were studied in terms of the microbial agents involved, length of outbreak, and attack rate (1.9-66.7%). The most frequent bacteria were methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii. Screening of staff revealed carrier rates of 0 to 20% in 16 studies. Environmental samples were taken in 21 studies and were positive in 14 of them. The mortality rate among infected patients varied from 0 to 33%. Implementation of isolation precautions did not always suffice, with unit closure being necessary in five outbreaks. The lack of consensus on how to manage such outbreak was highlighted. MDRB infections or colonizations are responsible for increased morbidity and mortality in vulnerable burn patients. Their management is problematic because of multifactorial transmission and limited therapeutic possibilities.

Hospital-associated methicillin-resistant Staphylococcus aureus: A cross-sectional analysis of risk factors in South African tertiary public hospitals

Introduction

Hospital-associated methicillin-resistant S. aureus (HA-MRSA) remains a significant cause of morbidity and mortality worldwide. We conducted a study to determine risk factors for HA-MRSA in order to inform control strategies in South Africa.

Methods

We used surveillance data collected from five tertiary hospitals in Gauteng and Western Cape provinces during 2014 for analysis. A case of HA-MRSA was defined as isolation of MRSA from a blood culture 48 hours after admission and/or if the patient was hospitalised in the six months prior to the current culture. Multivariable logistic regression modelling was used to determine risk factors for HA-MRSA.

Results

Of the 9971 patients with positive blood cultures, 7.7% (772) had S. aureus bacteraemia (SAB). The overall prevalence of MRSA among those with SAB was 30.9% (231/747; 95% confidence interval [CI] 27.6%– 34.3%). HA-MRSA infections accounted for 28.3% of patients with SAB (207/731; 95% CI 25.1%– 31.7%). Burns (adjusted odds ratio [aOR] 12.7; 95% CI 4.7–34.4), age ≤1 month (aOR 8.7; 95% CI 3.0–24.6), residency at a long-term care facility (aOR 5.2; 95% CI, 1.5–17.4), antibiotic use within two months of the current SAB episode (aOR 5.1; 95% CI 2.8–9.1), hospital stay of 13 days or more (aOR 2.8; 95% CI 1.3–5.6) and mechanical ventilation (aOR 2.2; 95% CI 1.07–4.6), were independent risk factors for HA-MRSA infection.

Conclusion

The prevalence of MRSA remains high in South African tertiary public hospitals. Several identified risk factors of HA-MRSA infections should be considered when instituting infection and prevention strategies in public-sector hospitals, including intensifying the implementation of antimicrobial stewardship programmes. There is an urgent need to strengthen infection prevention and control in burn wards, neonatal wards, and intensive care units which house mechanically ventilated patients.

[Molecular diagnosis of methicillin-resistent Staphylococcus aureus: Methods and efficacy]

Methicillin-resistant Staphylococcus aureus (MRSA) isolates are a serious public health problem whose ever-increasing rate is commensurate with the pressure it is exerting on the healthcare system. At present, more than 20% of clinical S. aureus isolates in German hospitals are methicillin-resistant, in Austria less than 10%. Strategies from low-prevalence countries show that this development is not necessarily inevitable. In the Scandinavian countries and the Netherlands, thanks to a rigorous prevention programme, MRSA prevalence has been kept at an acceptably low level (< 1-3%). Central to these search-and-destroy control strategies is an admission screening using several MRSA swabs taken from mucocutaneous colonisation sites of high-risk patients (MRSA surveillance). It has also been reported that the speed with which MRSA carriage is detected has an important role, as it is a key component of any effective strategy to prevent the pathogen from spreading. Since MRSA culturing involves a 2-3 day delay before the final results are available, rapid detection techniques (commonly referred to as MRSA rapid tests) using polymerase chain reaction (PCR) methods and, most recently, rapid culturing methods have been developed. The implementation of rapid tests reduces the time of detection of MRSA carriers from 48-72 to 2-5 h. Clinical evaluation data have shown that MRSA can thus be detected with very high sensitivity. Specificity, however, is sometimes impaired due to false-positive PCR signals occurring in mixed flora specimens. In order to rule out false-positive PCR results, a culture screen must always be carried out simultaneously. The data provide preliminary evidence that a PCR assay can reduce nosocomial MRSA transmission in high-risk patients or high-risk areas, whereas an approach that screens all patients admitted to the hospital is probably not effective. Information concerning the cost effectiveness of rapid MRSA tests is still sparse and thus the issue remains debated.

Elimination of Routine Contact Precautions for Endemic Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus: A Retrospective Quasi-Experimental Study

OBJECTIVE To evaluate the impact of discontinuation of contact precautions (CP) for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) and expansion of chlorhexidine gluconate (CHG) use on the health system. DESIGN Retrospective, nonrandomized, observational, quasi-experimental study. SETTING Two California hospitals. PARTICIPANTS Inpatients. METHODS We compared hospital-wide laboratory-identified clinical culture rates (as a marker of healthcare-associated infections) 1 year before and after routine CP for endemic MRSA and VRE were discontinued and CHG bathing was expanded to all units. Culture data from patients and cost data on material utilization were collected. Nursing time spent donning personal protective equipment was assessed and quantified using time-driven activity-based costing. RESULTS Average positive culture rates before and after discontinuing CP were 0.40 and 0.32 cultures/100 admissions for MRSA (P=.09), and 0.48 and 0.40 cultures/100 admissions for VRE (P=.14). When combining isolation gown and CHG costs, the health system saved $643,776 in 1 year. Before the change, 28.5% intensive care unit and 19% medicine/surgery beds were on CP for MRSA/VRE. On the basis of average room entries and donning time, estimated nursing time spent donning personal protective equipment for MRSA/VRE before the change was 45,277 hours/year (estimated cost, $4.6 million). CONCLUSION Discontinuing routine CP for endemic MRSA and VRE did not result in increased rates of MRSA or VRE after 1 year. With cost savings on materials, decreased healthcare worker time, and no concomitant increase in possible infections, elimination of routine CP may add substantial value to inpatient care delivery. Infect Control Hosp Epidemiol 2016;1-8.

Contact Precautions More Is Not Necessarily Better

Objective.

To determine whether increases in contact isolation precautions are associated with decreased adherence to isolation practices among healthcare workers (HCWs).

Design.

Prospective cohort study from February 2009 to October 2009.

Setting.

Eleven teaching hospitals.

Participants.

HCWs.

Methods.

One thousand thirteen observations conducted on HCWs. Additional data included the number of persons in isolation, types of HCWs, and hospital-specific contact precaution practices. Main outcome measures included compliance with individual components of contact isolation precautions (hand hygiene before and after patient encounter, donning of gown and glove upon entering a patient room, and doffing upon exiting) and overall compliance (all 5 measures together) during varying burdens of isolation.

Results.

Compliance with hand hygiene was as follows: prior to donning gowns/gloves, 37.2%; gowning, 74.3%; gloving, 80.1%; doffing of gowns/gloves, 80.1%; after gown/glove removal, 61%. Compliance with all components was 28.9%. As the burden of isolation increased (20% or less to greater than 60%), a decrease in compliance with hand hygiene (43.6%—4.9%) and with all 5 components (31.5%—6.5%) was observed. In multivariable analysis, there was an increase in noncompliance with all 5 components of the contact isolation precautions bundle (odds ratio [OR], 6.6 [95% confidence interval (CI), 1.15-37.44];P= .03) and in noncompliance with hand hygiene prior to donning gowns and gloves (OR, 10.1 [95% CI, 1.84—55.54];P= .008) associated with increasing burden of isolation.

Conclusions.

As the proportion of patients in contact isolation increases, compliance with contact isolation precautions decreases. Placing 40% of patients under contact precautions represents a tipping point for noncompliance with contact isolation precautions measures.

Strategies to Prevent Methicillin-ResistantStaphylococcus aureusTransmission and Infection in Acute Care Hospitals: 2014 Update

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their methicillin-resistantStaphylococcus aureus(MRSA) prevention efforts. This document updates “Strategies to Prevent Transmission of Methicillin-ResistantStaphylococcus aureusin Acute Care Hospitals,” published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates.

Impact of different diagnostic technologies for MRSA admission screening in hospitals - a decision tree analysis

BACKGROUND

Hospital infections with multiresistant bacteria, e.g., Methicillin-resistant Staphylococcus aureus (MRSA), cause heavy financial burden worldwide. Rapid and precise identification of MRSA carriage in combination with targeted hygienic management are proven to be effective but incur relevant extra costs. Therefore, health care providers have to decide which MRSA screening strategy and which diagnostic technology should be applied according to economic criteria.

AIM

The aim of this study was to determine which MRSA admission screening and infection control management strategy causes the lowest expected cost for a hospital. Focus was set on the Point-of-Care Testing (PoC).

METHODS

A decision tree analytic cost model was developed, primarily based on data from peer-reviewed literature. In addition, univariate sensitivity analyses of the different input parameters were conducted to study the robustness of the results.

FINDINGS

In the basic analysis, risk-based PoC screening showed the highest mean cost savings with 14.98 € per admission in comparison to no screening. Rapid universal screening methods became favorable at high MRSA prevalence, while in situations with low MRSA transmission rates omission of screening may be favorable.

CONCLUSION

Early detection of MRSA by rapid PoC or PCR technologies and consistent implementation of appropriate hygienic measures lead to high economic efficiency of MRSA management. Whether general or targeted screening is more efficient depends mainly on epidemiological and infrastructural parameters.

Cost-benefit analysis from the hospital perspective of universal active screening followed by contact precautions for methicillin-resistant Staphylococcus aureus carriers

OBJECTIVE To explore the economic impact to a hospital of universal methicillin-resistant Staphylococcus aureus (MRSA) screening. METHODS We used a decision tree model to estimate the direct economic impact to an individual hospital of starting universal MRSA screening and contact precautions. Projected costs and benefits were based on literature-derived data. Our model examined outcomes of several strategies including non-nares MRSA screening and comparison of culture versus polymerase chain reaction-based screening. RESULTS Under baseline conditions, the costs of universal MRSA screening and contact precautions outweighed the projected benefits generated by preventing MRSA-related infections, resulting in economic costs of $104,000 per 10,000 admissions (95% CI, $83,000-$126,000). Cost-savings occurred only when the model used estimates at the extremes of our key parameters. Non-nares screening and polymerase chain reaction-based testing, both of which identified more MRSA-colonized persons, resulted in more MRSA infections averted but increased economic costs of the screening program. CONCLUSIONS We found that universal MRSA screening, although providing potential benefit in preventing MRSA infection, is relatively costly and may be economically burdensome for a hospital. Policy makers should consider the economic burden of MRSA screening and contact precautions in relation to other interventions when choosing programs to improve patient safety and outcomes.

Reconsidering Contact Precautions for Endemic Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus

BACKGROUND

Whether contact precautions (CP) are required to control the endemic transmission of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) in acute care hospitals is controversial in light of improvements in hand hygiene, MRSA decolonization, environmental cleaning and disinfection, fomite elimination, and chlorhexidine bathing.

OBJECTIVE

To provide a framework for decision making around use of CP for endemic MRSA and VRE based on a summary of evidence related to use of CP, including impact on patients and patient care processes, and current practices in use of CP for MRSA and VRE in US hospitals.

DESIGN

A literature review, a survey of Society for Healthcare Epidemiology of America Research Network members on use of CP, and a detailed examination of the experience of a convenience sample of hospitals not using CP for MRSA or VRE.

PARTICIPANTS

Hospital epidemiologists and infection prevention experts.

RESULTS

No high quality data support or reject use of CP for endemic MRSA or VRE. Our survey found more than 90% of responding hospitals currently use CP for MRSA and VRE, but approximately 60% are interested in using CP in a different manner. More than 30 US hospitals do not use CP for control of endemic MRSA or VRE.

CONCLUSIONS

Higher quality research on the benefits and harms of CP in the control of endemic MRSA and VRE is needed. Until more definitive data are available, the use of CP for endemic MRSA or VRE in acute care hospitals should be guided by local needs and resources.

Infect Control Hosp Epidemiol 2015;36(10):1163–1172

An Ounce of Prevention Saves Tons of Lives: Infection in Burns

BACKGROUND

Modern day burn care continues to wage an uphill battle against an enemy that evolves faster than we can develop weapons. Bacteria (bioburden) are everywhere and can infiltrate anywhere within our susceptible population of burn patients. This is why prevention of infection is key to improving their survival and outcome.

PURPOSE

To reduce the incidence of infection in the burn patient population.

MATERIALS

Review of pertinent recent literature regarding infection prevention and control in the intensive care unit setting.

RESULTS

We propose that bioburden is one of the central elements in the infectious cycle that is ever-present in burn units. The mechanism of bacterial entry into the unit and subsequent transmission and infection are delineated. Recommendations for mitigating this risk are provided to guide future clinicians in their care of burn patients.

CONCLUSIONS

The treatment of infection and sepsis against highly adaptable bacteria is often insurmountable by ill patients. In this process, bioburden needs to be corralled to have any success. Thus, preventing organisms from entering the unit and transferring onto other patients, and eliminating the bacteria dwelling in the unit are all necessary actions in this battle. Ultimately, maintaining a culture that is constantly wary of this risk only can achieve this goal.

A targeted infection prevention intervention in nursing home residents with indwelling devices: a randomized clinical trial

IMPORTANCE

Indwelling devices (eg, urinary catheters and feeding tubes) are often used in nursing homes (NHs). Inadequate care of residents with these devices contributes to high rates of multidrug-resistant organisms (MDROs) and device-related infections in NHs.

OBJECTIVE

To test whether a multimodal targeted infection program (TIP) reduces the prevalence of MDROs and incident device-related infections.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial at 12 community-based NHs from May 2010 to April 2013. Participants were high-risk NH residents with urinary catheters, feeding tubes, or both.

INTERVENTIONS

Multimodal, including preemptive barrier precautions, active surveillance for MDROs and infections, and NH staff education.

MAIN OUTCOMES AND MEASURES

The primary outcome was the prevalence density rate of MDROs, defined as the total number of MDROs isolated per visit averaged over the duration of a resident's participation. Secondary outcomes included new MDRO acquisitions and new clinically defined device-associated infections. Data were analyzed using a mixed-effects multilevel Poisson regression model (primary outcome) and a Cox proportional hazards model (secondary outcome), adjusting for facility-level clustering and resident-level variables.

RESULTS

In total, 418 NH residents with indwelling devices were enrolled, with 34,174 device-days and 6557 anatomic sites sampled. Intervention NHs had a decrease in the overall MDRO prevalence density (rate ratio, 0.77; 95% CI, 0.62-0.94). The rate of new methicillin-resistant Staphylococcus aureus acquisitions was lower in the intervention group than in the control group (rate ratio, 0.78; 95% CI, 0.64-0.96). Hazard ratios for the first and all (including recurrent) clinically defined catheter-associated urinary tract infections were 0.54 (95% CI, 0.30-0.97) and 0.69 (95% CI, 0.49-0.99), respectively, in the intervention group and the control group. There were no reductions in new vancomycin-resistant enterococci or resistant gram-negative bacilli acquisitions or in new feeding tube-associated pneumonias or skin and soft-tissue infections.

CONCLUSIONS AND RELEVANCE

Our multimodal TIP intervention reduced the overall MDRO prevalence density, new methicillin-resistant S aureus acquisitions, and clinically defined catheter-associated urinary tract infection rates in high-risk NH residents with indwelling devices. Further studies are needed to evaluate the cost-effectiveness of this approach as well as its effects on the reduction of MDRO transmission to other residents, on the environment, and on referring hospitals.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01062841.

Optimization of pre-emptive isolations in a polyvalent ICU through implementation of an intervention strategy

BACKGROUND

Pre-emptive isolation refers to the application of contact precaution measures in patients with strongly suspected colonization by multiresistant bacteria.

OBJECTIVE

To assess the impact of an intervention program involving the implementation of a consensus-based protocol of pre-emptive isolation (CPPI) on admission to a polyvalent ICU of a general hospital.

METHODS

A comparative analysis of 2 patient cohorts was made: a historical cohort including patients in which pre-emptive isolation was established according to physician criterion prior to starting CPPI (from January 2010 to February 2011), and a prospective cohort including patients in which CPPI was implemented (from March to November 2011). CPPI included the identification and diffusion of pre-emptive isolation criteria, the definition of sampling methodology, the evaluation of results, and the development of criteria for discontinuation of pre-emptive isolation. Pre-emptive isolation was indicated by the medical staff, and follow-up was conducted by the nursing staff. Pre-emptive isolation was defined as "adequate" when at least one multiresistant bacteria was identified in any of the samples. Comparison of data between the 2 periods was made with the chi-square test for categorical variables and the Student t-test for quantitative variables. Statistical significance was set at P<.05.

RESULTS

Among the 1,740 patients admitted to the ICU (1,055 during the first period and 685 during the second period), pre-emptive isolation was indicated in 199 (11.4%); 111 (10.5%) of these subjects corresponded to the historical cohort (control group) and 88 (12.8%) to the posterior phase after the implementation of CPPI (intervention group). No differences were found in age, APACHE II score or patient characteristics between the 2 periods. The implementation of CPPI was related to decreases in non-indicated pre-emptive isolations (29.7 vs. 6.8%, P<.001), time of requesting surveillance cultures (1.56 vs. 0.37 days, P<.001), and days of duration of treatment (4.77 vs. 3.58 days, P<.001). In 44 patients (22.1%) in which pre-emptive isolation was indicated, more than one multiresistant bacteria was identified, with an "adequate pre-emptive isolation rate" of 19.8% in the first period and 25.0% in the second period (P<.382).

CONCLUSIONS

The implementation of CPPI resulted in a significant decrease in pre-emptive isolations which were not indicated correctly, a decrease in the time elapsed between isolation and collection of samples, and a decrease in the duration of isolation measures in cases in which isolation was unnecessary, without increasing the rate of "adequate pre-emptive isolation".

Extremely high prevalence of antiseptic resistant Quaternary Ammonium Compound E gene among clinical isolates of multiple drug resistant Acinetobacter baumannii in Malaysia

Background

Antiseptics are commonly used for the management of MDR (multiple drug resistance) pathogens in hospitals. They play crucial roles in the infection control practices. Antiseptics are often used for skin antisepsis, gauze dressing, preparation of anatomical sites for surgical procedure, hand sterilization before in contact with an infected person, before an invasive procedure and as surgical scrub.

Methods

We screened 122 multiple drug resistant Acinetobacter baumannii (MDRAB) isolated from admitted patients in one of the tertiary care hospital in Malaysia for the presence of antiseptic resistant genes qacA and qacE (Quaternary Ammonium Compound) and susceptibility towards chlorhexidine (CLX), benzalkonium (BZK) and benzethonium (BZT).

Results

Eighty-nine (73%) isolates harboured qacE gene, while none were positive for qacA. The MIC ranged from 0.2 to 0.6 for CLX, 0.02 to 0.2 for BZK and 0.04 to 0.2 μg/mL for BZT. The highest number of qacE positive isolates were obtained from surgery (n = 24; 27%; p < 0.05), followed by medical ward (n = 23; 25.8%) and ICU (n = 21; 23.6%). Majority of the isolates from wound swabs (n = 33; 37%), T/aspirate (n = 16; 18%) and tissue (n = 10; 11.2%) harboured the qacE genes.

Conclusion

The present investigation showed high prevalence of qacE gene among the studied isolates. Antiseptics are important components of infection control, continuous monitoring of antiseptics use in the hospital is cautioned.

Impact of a Mandatory Infection Control Education Program on Nosocomial Acquisition of Methicillin-ResistantStaphylococcus aureus

Objective.

To assess the impact of an institution-wide infection control education program on the rate of transmission of methicillin-resistantStaphylococcus aureus(MRSA).

Design.

Before-and-after study.

Setting.

A 472-bed, urban, university-affiliated hospital.

Intervention.

During the period March-May 2004, all hospital staff completed a mandatory infection control education program, including the receipt of hospital-specific MRSA data and case-based practice with additional precautions.

Outcome Measure.

The rate of nosocomial MRSA acquisition was calculated as the number of cases of nosocomial MRSA acquisition per 100 days that a person with MRSA colonization or infection detected at admission is present in the hospital (“admission MRSA” exposure-days) for 3 time periods: June 2002-February 2003 (before the Toronto outbreak of severe acute respiratory syndrome [SARS]), June 2003-February 2004 (after the outbreak of SARS), and June 2004-February 2005 (after education). A case of nosocomial acquisition of MRSA colonization or infection represented a patient first identified as colonized or infected more than 72 hours after admission or at admission after a previous hospitalization.

Results.

The rate of nosocomial acquisition of MRSA colonization or infection was 8.8 cases per 100 admission MRSA exposure-days for the period before SARS, 3.8 cases per 100 admission MRSA exposure-days for the period after SARS (P< .001 for before SARS vs after SARS), and 1.9 cases per 100 admission MRSA exposure-days for the period after education (P= .02 for after education vs before education). The volume of alcohol-based handrub purchased was apparently stable, with 4,010 L during fiscal year 2003-2004 (April 2003-March 2004) compared with 3,780 L during fiscal year 2004—2005. The observed rate of compliance with hand washing did not change significantly (40.9% during education vs 44.2% after education;P= .23). The total number of patients screened for MRSA colonization was not different in the 3 periods.

Conclusions.

The rate of nosocomial acquisition of MRSA colonization or infection decreased after SARS and was further reduced in association with a hospital-wide education program.

Strategies to Prevent Transmission of Methicillin-ResistantStaphylococcus aureusin Acute Care Hospitals

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). Our intent in this document is to highlight practical recommendations in a concise format to assist acute care hospitals in their efforts to prevent transmission of methicillin-resistantStaphylococcus aureus(MRSA). Refer to the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America “Compendium of Strategies to Prevent Healthcare-Associated Infections” Executive Summary, Introduction, and accompanying editorial for additional discussion.

1. Burden of HAIs caused by MRSA in acute care facilities

a. In the United States, the proportion of hospital-associatedS. aureusinfections that are caused by strains resistant to methicillin has steadily increased. In 2004, MRSA accounted for 63% ofS. aureusinfections in hospitals.

b. Although the proportion ofS. aureus–associated HAIs among intensive care unit (ICU) patients that are due to methicillin-resistant strains has increased (a relative measure of the MRSA problem), recent data suggest that the incidence of central line–associated bloodstream infection caused by MRSA (an absolute measure of the problem) has decreased in several types of ICUs since 2001. Although these findings suggest that there has been some success in preventing nosocomial MRSA transmission and infection, many patient groups continue to be at risk for such transmission.

c. MRSA has also been documented in other areas of the hospital and in other types of healthcare facilities, including those that provide long-term care.

Active Surveillance for Methicillin-Resistant Staphylococcus aureus in the Neonatal Intensive Care Unit

Background.

We describe our experience using a real-time polymerase chain reaction (PCR) assay for methicillin-resistant Staphylococcus aureus (MRSA) during a period of active surveillance in the neonatal intensive care unit (NICU) from March 2007 until November 2007.

Objective.

TO compare PCR with bacterial culture methods and find the screening algorithm that most successfully ensures appropriate isolation of colonized patients.

Methods.

Patients in the NICU were screened for MRSA on admission and weekly thereafter until discharge. Healthcare workers (HCWs) were also screened as part of an outbreak investigation. A total of 599 individuals were screened for MRSA with both a PCR assay and selective bacterial culture. Strain typing was performed on all MRSA isolates to determine clonal relatedness.

Results.

Twenty-one of 435 infants (4.8%) screened positive for MRSA with the PCR assay. Only 11 patients (52.4%) had concomitant bacterial cultures positive for MRSA. Compared to bacterial culture, the PCR assay had a sensitivity of 100% and a specificity of 97.6%, with a positive predictive value (PPV) of 52.4%. Infants that tested positive for MRSA by both culture and PCR were more likely to have a positive PCR assay result when retested than were those who tested positive by PCR alone (80% vs 20%; P = .02). Strain typing of MRSA isolates identified a common clone in only 2 colonized infants.

Conclusion.

Our data show that, in our neonatal population, the reproducibility of PCR assay results for culture-negative patients was low compared with the reproducibility of results for culture-positive Patients. Furthermore, the low PPV suggests that for nearly half of individuals who were PCR-positive, the result was falsely positive, which argues against the use of PCR assays alone for MRSA screening in the NICU.

Infection control in the intensive care unit

It is critical for health care personnel to recognize and appreciate the detrimental impact of intensive care unit (ICU)-acquired infections. The economic, clinical, and social expenses to patients and hospitals are overwhelming. To limit the incidence of ICU-acquired infections, aggressive infection control measures must be implemented and enforced. Researchers and national committees have developed and continue to develop evidence-based guidelines to control ICU infections. A multifaceted approach, including infection prevention committees, antimicrobial stewardship programs, daily reassessments-intervention bundles, identifying and minimizing risk factors, and continuing staff education programs, is essential. Infection control in the ICU is an evolving area of critical care research.

Efficacy of face masks and respirators in preventing upper respiratory tract bacterial colonization and co-infection in hospital healthcare workers

OBJECTIVE

We compared the efficacy of medical masks (MM) and N95 respirators (N95) in preventing bacterial colonization/infection in healthcare workers (HCWs).

METHODS

A cluster randomized clinical trial (RCT) of 1441 hospital HCWs randomized to medical masks or N95 respirators, and compared to 481 control HCWs, was performed in Beijing, China, during the winter season of 2008-2009. Participants were followed for development of clinical respiratory illness (CRI). Symptomatic subjects were tested for Streptococcus pneumoniae, Bordetella pertussis, Chlamydia pneumoniae, Mycoplasma pneumoniae or Haemophilus influenza type B by multiplex polymerase chain reaction (PCR).

RESULTS

The rate of bacterial colonization was 2.8% in the N95 group (p=0.02), 5.3% among medical mask users (p<0.01) and 7.5% among the controls (p=0.16). N95 respirators were significantly protective (adjusted RR 0.34, 95% CI: 0.21-0.56) against bacterial colonization. Co-infections of two bacteria or a virus and bacteria occurred in up to 3.7% of HCWs, and were significantly lower in the N95 arm.

CONCLUSIONS

N95 respirators were significantly protective against bacterial colonization, co-colonization and viral-bacterial co-infection. We showed that dual respiratory virus or bacterial-viral co-infections can be reduced by the use of N95 respirators. This study has occupational health and safety implications for health workers.

Framework for controlling infection through isolation precautions in Japan

In Japan, nurses certified in infection control face organizational and structural challenges to the implementation of the recommended isolation precautions. In this study, we developed a conceptual framework for the problem-solving process of certified nurses in infection control when implementing appropriate isolation-precaution measures. We conducted a qualitative, descriptive study using directed content analysis. Semistructured interviews were conducted with 40 nurses who had over five years' experience in infection control. Factors assessing the risk of infection in patients were identified, including microorganism characteristics, patient characteristics, and risk of infection to the entire unit. The nurses also assessed the risk of infection in institutions from the following perspectives: organizational culture, infection control system, human resources, environment surrounding the facility, ethical issues, and external factors. Individual characteristics, such as attributes, knowledge, expertise, and job function, were identified as major influencing factors in the problem-solving process. These findings could be useful for newly-certified nurses in infection control and provide recommendations on implementing isolation-precaution measures.

A bundled approach to reduce methicillin-resistant Staphylococcus aureus infections in a system of community hospitals

Methicillin-resistant Staphylococcus aureus (MRSA) infections pose a significant challenge to U.S. healthcare facilities, but there has been limited study of initiatives to reduce infection and increase patient safety in community hospitals. To address this need, a multifaceted program for MRSA infection prevention was developed for implementation in 159 acute care facilities. This program featured five distinct tools-active MRSA surveillance of high-risk patients, enhanced barrier precautions, compulsive hand hygiene, disinfection and cleaning, and executive champions and patient empowerment-and was implemented during 1Q-2Q 2007. Postintervention (3Q 2007-2Q 2008), 10.2% of patients with high-risk for infection or complications due to MRSA had nasal colonization. Volume of disposable gown and alcohol-based hand sanitizer use increased substantially following program implementation. Self-reported rates, based on NHSN definitions, of healthcare-associated central line-associated bloodstream infections and ventilator-associated pneumonia due to MRSA decreased 39% (p < .001) and 54% (p < .001), respectively. Infection rates continued to decrease during the follow-up period (1Q-4Q 2009). This sustained improvement demonstrates that reducing healthcare-associated MRSA infections in a large number of diverse facilities is possible and that a "bundled" approach that translates science into clinical and executive performance expectations may aid in overcoming traditional barriers to implementation.

Universal glove and gown use and acquisition of antibiotic-resistant bacteria in the ICU: a randomized trial

IMPORTANCE

Antibiotic-resistant bacteria are associated with increased patient morbidity and mortality. It is unknown whether wearing gloves and gowns for all patient contact in the intensive care unit (ICU) decreases acquisition of antibiotic-resistant bacteria.

OBJECTIVE

To assess whether wearing gloves and gowns for all patient contact in the ICU decreases acquisition of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) compared with usual care.

DESIGN, SETTING, AND PARTICIPANTS

Cluster-randomized trial in 20 medical and surgical ICUs in 20 US hospitals from January 4, 2012, to October 4, 2012.

INTERVENTIONS

In the intervention ICUs, all health care workers were required to wear gloves and gowns for all patient contact and when entering any patient room.

MAIN OUTCOMES AND MEASURES

The primary outcome was acquisition of MRSA or VRE based on surveillance cultures collected on admission and discharge from the ICU. Secondary outcomes included individual VRE acquisition, MRSA acquisition, frequency of health care worker visits, hand hygiene compliance, health care–associated infections, and adverse events.

RESULTS

From the 26,180 patients included, 92,241 swabs were collected for the primary outcome. Intervention ICUs had a decrease in the primary outcome of MRSA or VRE from 21.35 acquisitions per 1000 patient-days (95% CI, 17.57 to 25.94) in the baseline period to 16.91 acquisitions per 1000 patient-days (95% CI, 14.09 to 20.28) in the study period, whereas control ICUs had a decrease in MRSA or VRE from 19.02 acquisitions per 1000 patient-days (95% CI, 14.20 to 25.49) in the baseline period to 16.29 acquisitions per 1000 patient-days (95% CI, 13.48 to 19.68) in the study period, a difference in changes that was not statistically significant (difference, −1.71 acquisitions per 1000 person-days, 95% CI, −6.15 to 2.73; P = .57). For key secondary outcomes, there was no difference in VRE acquisition with the intervention (difference,  0.89 acquisitions per 1000 person-days; 95% CI, −4.27 to 6.04, P = .70), whereas for MRSA, there were fewer acquisitions with the intervention (difference, −2.98 acquisitions per 1000 person-days; 95% CI, −5.58 to −0.38; P = .046). Universal glove and gown use also decreased health care worker room entry (4.28 vs 5.24 entries per hour, difference, −0.96; 95% CI, −1.71 to −0.21, P = .02), increased room-exit hand hygiene compliance (78.3% vs 62.9%, difference, 15.4%; 95% CI, 8.99% to 21.8%; P = .02) and had no statistically significant effect on rates of adverse events (58.7 events per 1000 patient days vs 74.4 events per 1000 patient days; difference, −15.7; 95% CI, −40.7 to 9.2, P = .24).

CONCLUSIONS AND RELEVANCE

The use of gloves and gowns for all patient contact compared with usual care among patients in medical and surgical ICUs did not result in a difference in the primary outcome of acquisition of MRSA or VRE. Although there was a lower risk of MRSA acquisition alone and no difference in adverse events, these secondary outcomes require replication before reaching definitive conclusions.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT0131821.

A systematic literature review and meta-analysis of factors associated with methicillin-resistant Staphylococcus aureus colonization at time of hospital or intensive care unit admission

OBJECTIVE

Screening for methicillin-resistant Staphylococcus aureus (MRSA) in high-risk patients is a legislative mandate in 9 US states and has been adopted by many hospitals. Definitions of high risk differ among hospitals and state laws. A systematic evaluation of factors associated with colonization is lacking. We performed a systematic review of the literature to assess factors associated with MRSA colonization at hospital admission.

DESIGN

We searched MEDLINE from 1966 to 2012 for articles comparing MRSA colonized and noncolonized patients on hospital or intensive care unit (ICU) admission. Data were extracted using a standardized instrument. Meta-analyses were performed to identify factors associated with MRSA colonization.

RESULTS

We reviewed 4,381 abstracts; 29 articles met inclusion criteria (n = 76,913 patients). MRSA colonization at hospital admission was associated with recent prior hospitalization (odds ratio [OR], 2.4 [95% confidence interval (CI), 1.3-4.7]; P < .01), nursing home exposure (OR, 3.8 [95% CI, 2.3-6.3]; P < .01), and history of exposure to healthcare-associated pathogens (MRSA carriage: OR, 8.0 [95% CI, 4.2-15.1]; Clostridium difficile infection: OR, 3.4 [95% CI, 2.2-5.3]; vancomycin-resistant Enterococci carriage: OR, 3.1 [95% CI, 2.5-4.0]; P < .01 for all). Select comorbidities were associated with MRSA colonization (congestive heart failure, diabetes, pulmonary disease, immunosuppression, and renal failure; P < .01 for all), while others were not (human immunodeficiency virus, cirrhosis, and malignancy). ICU admission was not associated with an increased risk of MRSA colonization (OR, 1.1 [95% CI, 0.6-1.8]; P = .87).

CONCLUSIONS

MRSA colonization on hospital admission was associated with healthcare contact, previous healthcare-associated pathogens, and select comorbid conditions. ICU admission was not associated with MRSA colonization, although this is commonly used in state mandates for MRSA screening. Infection prevention programs utilizing targeted MRSA screening may consider our results to define patients likely to have MRSA colonization.

Molecular epidemiology of methicillin-resistant Staphylococcus aureus in a burn unit from Brazil

Methicillin-resistant Staphylococcus aureus (MRSA) poses a threat for patients in burn units. Studies that mix epidemiological designs with molecular typing may contribute to the development of strategies for MRSA control. We conducted a study including: molecular characterization of Staphylococcal Chromosome Cassette mecA (SCCmec), strain typing with pulsed field gel electrophoresis (PFGE) and detection of virulence genes, altogether with a case-case-control study that assessed risk factors for MRSA and for methicillin-susceptible S. aureus (MSSA), using S. aureus negative patients as controls. Strains were collected from clinical and surveillance cultures from October 2006 through March 2009. MRSA was isolated from 96 patients. Most isolates (94.8%) harbored SCCmec type III. SCCmec type IV was identified in isolates from four patients. In only one case it could be epidemiologically characterized as "community-associated". PFGE typing identified 36 coexisting MRSA clones. When compared to MSSA (38 isolates), MRSA isolates were more likely to harbor two virulence genes: tst and lukPV. Previous stay in other hospital and admission to Intensive Care Unit were independent risk factors for both MRSA and MSSA, while the number of burn wound excisions was significantly related with the former (OR=6.80, 95%CI=3.54-13.07). In conclusion, our study found polyclonal endemicity of MRSA in a burn unit, possibly related to importing of strains from other hospitals. Also, it pointed out to a role of surgical procedures in the dissemination of MRSA strains.

Communication interventions to improve adherence to infection control precautions: a randomised crossover trial

Background

Ineffective communication of infection control requirements during transitions of care is a potential cause of non-compliance with infection control precautions by healthcare personnel. In this study, interventions to enhance communication during inpatient transfers between wards and radiology were implemented, in the attempt to improve adherence to precautions during transfers.

Methods

Two interventions were implemented, comprising (i) a pre-transfer checklist used by radiology porters to confirm a patient’s infectious status; (ii) a coloured cue to highlight written infectious status information in the transfer form. The effectiveness of the interventions in promoting adherence to standard precautions by radiology porters when transporting infectious patients was evaluated using a randomised crossover trial at a teaching hospital in Australia.

Results

300 transfers were observed over a period of 4 months. Compliance with infection control precautions in the intervention groups was significantly improved relative to the control group (p < 0.01). Adherence rate in the control group was 38%. Applying the coloured cue resulted in a compliance rate of 73%. The pre-transfer checklist intervention achieved a comparable compliance rate of 71%. When both interventions were applied, a compliance rate of 74% was attained. Acceptability of the coloured cue was high, but adherence to the checklist was low (40%).

Conclusions

Simple measures to enhance communication through the provision of a checklist and the use a coloured cue brought about significant improvement in compliance with infection control precautions by transport personnel during inpatient transfers. The study underscores the importance of effective communication in ensuring compliance with infection control precautions during transitions of care.

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.

Quantifying the impact of extranasal testing of body sites for methicillin-resistant Staphylococcus aureus colonization at the time of hospital or intensive care unit admission

OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of healthcare-associated infections. Recent legislative mandates require nares screening for MRSA at hospital and intensive care unit (ICU) admission in many states. However, MRSA colonization at extranasal sites is increasingly recognized. We conducted a systematic review of the literature to identify the yield of extranasal testing for MRSA.

DESIGN

We searched MEDLINE from January 1966 through January 2012 for articles comparing nasal and extranasal screening for MRSA colonization. Studies were categorized by population tested, specifically those admitted to ICUs and those admitted to hospitals with a high prevalence (6% or greater) or low prevalence (less than 6%) of MRSA carriers. Data were extracted using a standardized instrument.

RESULTS

We reviewed 4,381 abstracts and 735 articles. Twenty-three articles met the criteria for analysis ((n = 39,479 patients). Extranasal MRSA screening increased the yield by approximately one-third over nares alone. The yield was similar at ICU admission (weighted average, 33%; range, 9%-69%) and hospital admission in high-prevalence (weighted average, 37%; range, 9%-86%) and low-prevalence (weighted average, 50%; range, 0%-150%) populations. For comparisons between individual extranasal sites, testing the oropharynx increased MRSA detection by 21% over nares alone; rectum, by 20%; wounds, by 17%; and axilla, by 7%.

CONCLUSIONS

Extranasal MRSA screening at hospital or ICU admission in adults will increase MRSA detection by one-third compared with nares screening alone. Findings were consistent among subpopulations examined. Extranasal testing may be a valuable strategy for outbreak control or in settings of persistent disease, particularly when combined with decolonization or enhanced infection prevention protocols.

Reducing the spread of Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus on a burns unit through the intervention of an infection control bundle

Methicillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii are major nosocomial pathogens in burns units. We investigated the impact of an infection control bundle on the incidence of nosocomial MRSA and A. baumannii in our burns unit, comparing a pre-intervention period (December 2006-August 2008) with an intervention period (September 2008-December 2009). The bundle comprised regular hydrogen peroxide vapour (HPV) disinfection of the rooms following discharge of patients colonized or infected by multidrug-resistant bacteria, pre-emptive cohort isolation of newly admitted patients before being proven culture negative, cohorting of colonized or infected patients, installation of two air disinfection systems in the corridors of the unit and improvement of material storage. We also investigated the microbiological efficacy of HPV disinfection by sampling the environment before and after HPV treatments. HPV disinfection eliminated pathogens from the environment and significantly reduced total bacterial surface counts, and total fungal air and surface counts, on both a unit and room scale. The incidence of nosocomial MRSA infection or colonization fell by 89.3% from 7.22 to 0.77 cases/1000 patient days (p<0.0001) and A. baumannii fell by 88.8% from 6.92 to 0.77 cases/1000 patient days (p=0.002) in the intervention period with no further outbreaks of these organisms occurring in this period. The infection control bundle resulted in a significant reduction in the incidence of nosocomial MRSA and A. baumannii in our burns unit and prevented further outbreaks of these organisms.

A high prevalence of mupirocin and macrolide resistance determinant among Staphylococcus aureus strains isolated from burnt patients

Infections due to Staphylococcus aureus have become increasingly common among burn patients. The antibiotic resistance profile of S. aureus isolates and inducible resistance against clindamycin were investigated in this study. The presence of mecA gene, mupA gene and macrolide resistance genes were detected using PCR and multiplex-PCR. The resistance rate to methicillin, erythromycin and mupirocin were 58.5%, 58% and 40%, respectively. The prevalence of constitutive and inducible resistance among macrolide resistant isolates was 75% and 25%, respectively. Ninety five percent of the isolates were positive for one or more erm genes. The most common genes were ermA (75%), ermC (72%) and ermB (69%), respectively. The ermA gene predominated in the strains with the inducible phenotype, while ermC was more common in the isolates with the constitutive phenotype. The msrA gene was only found in one MRSA isolate with the constitutive phenotype. A total of 27 isolates (25%) carried the mupA gene. All the mupirocin resistant isolates and almost all the erythromycin resistant isolates were also resistant against methicillin which may indicate an outbreak of MRSA isolates with high-level mupirocin and erythromycin resistance in the burn unit assessed.

Clinical predictive values of extended-spectrum beta-lactamase carriage in patients admitted to medical wards

We aimed to reassess, through clinical items, populations at risk for extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) carriage at admission to hospital and to assess the risk of further positive clinical culture of ESBL-E among carriers. We performed a 5-month cohort study in a medicine ward of a 500-bed university teaching hospital in the Parisian area of France. All admitted patients were prospectively enrolled for rectal swabbing and clinical data collection, including bacterial infection at admission and during stay. Variables associated with ESBL-E carriage were identified by univariate and multivariate analysis. Five hundred patients were included. The prevalence of ESBL-E was 6.6% (33/500) upon admission. Only previous carriage of multidrug-resistant bacteria (MDRB) was associated with carriage (odds ratio [OR]: 17.7, 95% confidence interval (CI) 5.8-54.2, p < 0.001), yet, the positive predictive value (PPV) was not higher than 50%. When prior MDRB carriage was not considered in the multivariate analysis, only prior antibiotic consumption was found to be associated with carriage at admission (OR: 2.2 [1.1-4.5], p = 0.02). Two patients had ESBL-E infection at admission, yet, no patient became infected with ESBL-E during their stay. The clinical prediction of ESBL carriage at admission in our wards was found to be poorly efficient for assessing the at-risk population.

Pre-emptive contact precautions for intubated patients reduced healthcare-associated meticillin-resistant Staphylococcus aureus transmission and infection in an intensive care unit

Healthcare-associated infection by meticillin-resistant Staphylococcus aureus (MRSA) is still a great concern in an intensive care unit (ICU). Our surveillance data in the ICU revealed that intubated patients were at eight times higher risk of acquiring MRSA than non-intubated patients, so we hypothesised that pre-emptive contact precautions for all intubated patients would prevent healthcare-associated infection by MRSA in the ICU. Patients staying in our ICU for >2 days were included in this study. The study period was divided into two periods. During 2004 (1st period), contact precautions were performed only for patients with MRSA. During 2005–2007 (2nd period), contact precautions were applied to all intubated patients regardless of MRSA infection status. Patients were defined as MRSA-positive on admission when MRSA was detected by surveillance or clinical culture on enrolment. Other MRSA-positive results were defined as healthcare-associated MRSA (HA-MRSA) transmission. HA-MRSA infection was diagnosed according to the National Nosocomial Infections Surveillance Manual. The 1st period comprised 415 patients, and the 2nd period comprised 1280 patients. In intubated patients, HA-MRSA infection rate decreased significantly in the 2nd period (1st period 12.2%, 2nd period 5.6%; P = 0.015). HA-MRSA infection of all patients decreased from 3.6 to 2.3 incidents per 1000 patient-days (P < 0.05), despite a significant increase in the rate of patients MRSA positive on admission in the 2nd period (1st period 2.9%; 2nd period 6.1%). Pre-emptive contact precautions for intubated patients would be helpful in reducing HA-MRSA infection in ICU.

Accumulation and transport of microbial-size particles in a pressure protected model burn unit: CFD simulations and experimental evidence

BACKGROUND

Controlling airborne contamination is of major importance in burn units because of the high susceptibility of burned patients to infections and the unique environmental conditions that can accentuate the infection risk. In particular the required elevated temperatures in the patient room can create thermal convection flows which can transport airborne contaminates throughout the unit. In order to estimate this risk and optimize the design of an intensive care room intended to host severely burned patients, we have relied on a computational fluid dynamic methodology (CFD).

METHODS

The study was carried out in 4 steps: i) patient room design, ii) CFD simulations of patient room design to model air flows throughout the patient room, adjacent anterooms and the corridor, iii) construction of a prototype room and subsequent experimental studies to characterize its performance iv) qualitative comparison of the tendencies between CFD prediction and experimental results. The Electricité De France (EDF) open-source software Code_Saturne® (http://www.code-saturne.org) was used and CFD simulations were conducted with an hexahedral mesh containing about 300 000 computational cells. The computational domain included the treatment room and two anterooms including equipment, staff and patient. Experiments with inert aerosol particles followed by time-resolved particle counting were conducted in the prototype room for comparison with the CFD observations.

RESULTS

We found that thermal convection can create contaminated zones near the ceiling of the room, which can subsequently lead to contaminate transfer in adjacent rooms. Experimental confirmation of these phenomena agreed well with CFD predictions and showed that particles greater than one micron (i.e. bacterial or fungal spore sizes) can be influenced by these thermally induced flows. When the temperature difference between rooms was 7°C, a significant contamination transfer was observed to enter into the positive pressure room when the access door was opened, while 2°C had little effect. Based on these findings the constructed burn unit was outfitted with supplemental air exhaust ducts over the doors to compensate for the thermal convective flows.

CONCLUSIONS

CFD simulations proved to be a particularly useful tool for the design and optimization of a burn unit treatment room. Our results, which have been confirmed qualitatively by experimental investigation, stressed that airborne transfer of microbial size particles via thermal convection flows are able to bypass the protective overpressure in the patient room, which can represent a potential risk of cross contamination between rooms in protected environments.

Outbreak of community-acquired methicillin-resistant Staphylococcus aureus skin infections among health care workers in a cancer center

BACKGROUND

The incidence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) soft tissue infections is rising. However, CA-MRSA outbreaks among health care workers (HCWs) are rarely reported. We describe 3 clusters of CA-MRSA soft tissue infections among HCWs and the subsequent transmission to a patient.

METHODS

The first cluster of boils occurred in 4 employees who worked in the ambulatory treatment clinic (area A) and 1 patient (PA1) who frequently visited area A. Three employees (EA1, EA2, and EA3) and PA1 had positive cultures. Twelve employees in 2 geographically separate diagnostic imaging areas (areas B and C) reported recent or current boils of whom EB1, EB2, EB3, and EC1 had positive cultures. Molecular subtyping using pulse-field gel electrophoresis (PFGE) was performed on all 8 isolates and confirmed by the Centers for Disease Control and Prevention laboratory.

RESULTS

Relatedness of the MRSA strain was confirmed by PFGE in 7 of 8 isolates. Only EB3 was not related to the prototype CA-MRSA strain. All 7 related MRSA strains contained the typical genetic organization of staphylococcal cassette chromosome (SCC)-mec type IVa plus genes encoding Panton-Valentine Leukocidin. EB3's strain contained SCC-mec type II and was Panton-Valentine Leukocidin negative. A total of 171 questionnaires was sent. Nine of the 85 HCWs who responded reported a recent or current history of boils. Infection control conducted an education program for employees in areas A, B, and C.

CONCLUSION

Early identification and control of CA-MRSA infections among HCWs is important to limit horizontal transmission to patients. Future efforts should include educational programs and guidelines for reporting and treating HCWs with MRSA infections.