Isolation measures in the hospital management of methicillin resistant Staphylococcus aureus (MRSA): systematic review of the literature

Risk assessment and prediction of nosocomial infections based on surveillance data using machine learning methods

BACKGROUND

Nosocomial infections with heavy disease burden are becoming a major threat to the health care system around the world. Through long-term, systematic, continuous data collection and analysis, Nosocomial infection surveillance (NIS) systems are constructed in each hospital; while these data are only used as real-time surveillance but fail to realize the prediction and early warning function. Study is to screen effective predictors from the routine NIS data, through integrating the multiple risk factors and Machine learning (ML) methods, and eventually realize the trend prediction and risk threshold of Incidence of Nosocomial infection (INI).

METHODS

We selected two representative hospitals in southern and northern China, and collected NIS data from 2014 to 2021. Thirty-nine factors including hospital operation volume, nosocomial infection, antibacterial drug use and outdoor temperature data, etc. Five ML methods were used to fit the INI prediction model respectively, and to evaluate and compare their performance.

RESULTS

Compared with other models, Random Forest showed the best performance (5-fold AUC = 0.983) in both hospitals, followed by Support Vector Machine. Among all the factors, 12 indicators were significantly different between high-risk and low-risk groups for INI (P < 0.05). After screening the effective predictors through importance analysis, prediction model of the time trend was successfully constructed (R2 = 0.473 and 0.780, BIC = -1.537 and -0.731).

CONCLUSIONS

The number of surgeries, antibiotics use density, critical disease rate and unreasonable prescription rate and other key indicators could be fitted to be the threshold predictions of INI and quantitative early warning.

Infant isolation and cohorting for preventing or reducing transmission of healthcare-associated infections in neonatal units

BACKGROUND

Neonatal healthcare-associated infections (HAIs) result in increased morbidity and mortality, as well as increased healthcare costs. Patient isolation measures, i.e. single-room isolation or the cohorting of patients with similar infections, remain a recommended and commonly used practice for preventing horizontal spread of infections in the neonatal intensive care unit (NICU).  OBJECTIVES: Our primary objective was to assess the effect of single-room isolation or cohorting, or both for preventing transmission of HAIs or colonization with HAI-causing pathogens in newborn infants less than six months of age admitted to the neonatal intensive care unit (NICU). Our secondary objective was to assess the effect of single-room isolation or cohorting, or both on neonatal mortality and perceived or documented adverse effects in newborn infants admitted to the NICU.  SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, the WHO ICTRP and ClinicalTrials.gov trials registries. There were no restrictions to date, language or publication type. We also checked the reference lists of studies identified for full-text review.  SELECTION CRITERIA: Types of studies: cluster-randomized or quasi-randomized trials at the level of the cluster (where clusters may be defined by NICU, hospital, ward, or other subunits of the hospital). We also included cross-over trials with a washout period of more than four months (arbitrarily defined).

TYPES OF PARTICIPANTS

newborn infants less than six months of age in neonatal units that implemented patient isolation or cohorting as infection control measures to prevent HAIs. Types of interventions: patient isolation measures (single-room isolation or cohorting, or both of infants with similar colonization or infections) compared to routine isolation measures.

TYPES OF OUTCOME MEASURES

the primary outcome was the rate of transmission of HAIs as estimated by the infection and colonization rates in the NICU. Secondary outcomes included all-cause mortality during hospital stay at 28 days of age, length of hospital stay, as well as potential adverse effects of isolation or cohorting measures, or both.

DATA COLLECTION AND ANALYSIS

The standard methods of Cochrane Neonatal were used to identify studies and assess the methodological quality of eligible cluster-randomized trials. The certainty of the evidence was to be assessed by the GRADE method as evidence of high, moderate, low, or very low certainty. Infection and colonization rates were to be expressed as rate ratios for each trial and if appropriate for meta-analysis, the generic inverse variance method in RevMan was to be used.

MAIN RESULTS

We did not identify any published or ongoing trials to include in the review.

AUTHORS' CONCLUSIONS

The review found no evidence from randomized trials to either support or refute the use of patient isolation measures (single-room isolation or cohorting) in neonates with HAIs. Risks secondary to infection control measures need to be balanced against the benefits of decreasing horizontal transmission in the neonatal unit for optimal neonatal outcomes. There is an urgent need to research the effectiveness of patient isolation measures for preventing the transmission of HAIs in neonatal units. Well-designed trials randomizing clusters of units or hospitals to a type of patient isolation method intervention are warranted.

Impact of Multidisciplinary Collaborative Intervention on Isolation Implementation in Prevention and Control of Multi-drug Resistance Infection

OBJECTIVE

Contact precautions, especially the initiation of isolation, are important measures to prevent and control multidrug-resistant organisms (MDROs). However, the implementation in clinical practice remains weak. This study aimed to analyze the impact of multidisciplinary collaborative intervention on isolation implementation in multidrug-resistant infection, and determine the factors that affect the implementation of isolation measures.

METHODS

A multidisciplinary collaborative intervention related to isolation was conducted at a teaching tertiary hospital in central China on November 1, 2018. The information of 1338 patients with MDRO infection and colonization at 10 months before and after the intervention was collected. Then, the issuance of isolation orders was retrospectively analyzed. Univariate analysis and multivariate logistic regression analysis were performed to analyze the factors that affected the isolation implementation.

RESULTS

The overall issuance rate of isolation orders was 61.21%, which increased from 33.12% to 75.88% (P<0.001) after the implementation of the multidisciplinary collaborative intervention. The intervention (P<0.001, OR=0.166) was a promoting factor for the issuance of isolation orders, in addition to the length of stay (P=0.004, OR=0.991), department (P=0.004), and microorganism (P=0.038).

CONCLUSION

The isolation implementation remains far lower than policy standards. Multidisciplinary collaborative interventions can effectively improve the compliance to isolation measures implemented by doctors, thereby promoting the standardized management of MDROs, and providing reference for further improving the quality of hospital infection management.

Adverse Events Associated with Patient Isolation: A Systematic Literature Revue and Meta-analysis

BACKGROUND

Patient isolation is widely recommended and used in healthcare institutions to prevent transmission of MDRO. However, its risk-benefit ratio is debated.

AIM

We undertook a systematic literature review and meta-analysis since 2009 to assess, based on the newly published studies, whether or not there are physical and psychological adverse events associated with patient isolation.

METHODS

Systematic literature review and meta-analysis were performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Studies were systematically searched from PubMed, from the 1^st of may 2009 till the 31^st of January 2020. The concepts of the research questions were defined as: "Adverse events", "patient isolation or cohorting", and "multi-drug resistant organisms colonized or infection patients". Three reviewers independently screened studies and extracted data. All statistical analysis was performed with Stata Software and R.

FINDINGS

After screening titles of 15921 articles, abstracts of 196 and reviewing full texts of 50 studies, we included 19 studies. Studies were divided into 3 groups: 4 qualitative studies, 7 observational studies suitable for meta-analysis and 8 other observational studies. Meta-analysis shows no adverse events related to clinical care or patient's experience associated with patient isolation.

CONCLUSIONS

More studies with correct methodology, including a control group and standardized inclusion criteria, must be conducted to confirm our results.

Occupational Health and Safety Measures in Healthcare Settings during COVID-19: Strategies for Protecting Staff, Patients and Visitors

The COVID-19 (SARS-CoV-2) pandemic has profoundly impacted almost every aspect of healthcare systems worldwide, placing the health and safety of frontline healthcare workers at risk, and it still continues to remain an important public health challenge. Several hospitals have put in place strategies to manage space, staff, and supplies in order to continue to deliver optimum care to patients while at the same time protecting the health and safety of staff and patients. However, the emergence of the second and third waves of the virus with the influx of new cases continue to add an additional level of complexity to the already challenging situation of containing the spread and lowering the rate of transmission, thus pushing healthcare systems to the limit. In this narrative review paper, we describe various strategies including administrative controls, environmental controls, and use of personal protective equipment, implemented by occupational health and safety departments for the protection of healthcare workers, patients, and visitors from SARS-CoV-2 virus infection. The protection and safeguard of the health and safety of healthcare workers and patients through the implementation of effective infection control measures, adequate management of possible outbreaks and minimization of the risk of nosocomial transmission is an important and effective strategy of SARS-CoV-2 pandemic management in any healthcare facility. High quality patient care hinges on ensuring that the care providers are well protected and supported so they can provide the best quality of care to their patients.

Methicillin-Resistant Staphylococcus aureus Nasal Colonization Among Health Care Workers of a Tertiary Hospital in Ecuador and Associated Risk Factors

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is resistant to most of the commonly used antibiotics and is therefore a public health issue. Colonization with MRSA is a risk factor for infection or transmission.

Purpose

To determine the prevalence of colonization with Staphylococcus aureus (SA) and MRSA strains in health care workers (HCWs) at a tertiary hospital in Ecuador and to determine the risk factors associated with carriage.

Methods

Out of a cohort of 3800 HCWs, 481 individuals from different hospital departments were randomly selected, and a single nasal swab was collected. Detection of SA and MRSA was carried out with the LightCycler^® MRSA Advanced Test. A questionnaire was performed that gathered demographic and occupational information of the participants to determine risk factors for MRSA colonization. Statistical analysis was performed with univariate and multivariate analysis and the R-software version 4.0.2.

Results

Colonization with SA and MRSA occurred in respectively 23.7% (95% CI, 22.7–24.6) and 5% (95% CI, 3.39–7.58) of the individuals. The multivariate analysis showed that being older in age (OD 1.09) and being male (OD 2.78) were risk factors for SA and MRSA colonization (p-value < 0.001). Previous use of antibiotics or the use of nasal ointments diminished the colonization rates of SA (24% versus 3.7% and 10.1% respectively).

Conclusion

About 20% of the HCWs who were colonized with SA were colonized with MRSA, representing a risk for nosocomial infections and hospital outbreaks. Active monitoring and a decolonization treatment of the HCWs can reduce these risks.

A systematic review of the effectiveness of cohorting to reduce transmission of healthcare-associated C. difficile and multidrug-resistant organisms

BACKGROUND

Cohorting of patients and staff is a control strategy often used to prevent the spread of infection in healthcare institutions. However, a comprehensive evaluation of cohorting as a prevention approach is lacking.

METHODS

We performed a systematic review of studies that used cohorting as part of an infection control strategy to reduce hospital-acquired infections. We included studies published between 1966 and November 30, 2019, on adult populations hospitalized in acute-care hospitals.

RESULTS

In total, 87 studies met inclusion criteria. Study types were quasi-experimental "before and after" (n = 35), retrospective (n = 49), and prospective (n = 3). Case-control analysis was performed in 7 studies. Cohorting was performed with other infection control strategies in the setting of methicillin-resistant Staphylococcus aureus (MRSA, n = 22), Clostridioides difficile infection (CDI, n = 6), vancomycin-resistant Enterococcus (VRE, n = 17), carbapenem-resistant Enterobacteriaceae infections (CRE, n = 22), A. baumannii (n = 15), and other gram-negative infections (n = 5). Cohorting was performed either simultaneously (56 of 87, 64.4%) or in phases (31 of 87, 35.6%) to help contain transmission. In 60 studies, both patients and staff were cohorted. Most studies (77 of 87, 88.5%) showed a decline in infection or colonization rates after a multifaceted approach that included cohorting as part of the intervention bundle. Hand hygiene compliance improved in approximately half of the studies (8 of 15) during the respective intervention.

CONCLUSION

Cohorting of staff, patients, or both is a frequently used and reasonable component of an enhanced infection control strategy. However, determining the effectiveness of cohorting as a strategy to reduce transmission of MDRO and C. difficile infections is difficult, particularly in endemic situations.

The cost-effectiveness of temporary single-patient rooms to reduce risks of healthcare-associated infection

BACKGROUND

The use of single rooms for patient isolation often forms part of a wider bundle to prevent certain healthcare-associated infections (HAIs) in hospitals. Demand for single rooms often exceeds what is available and the use of temporary isolation rooms may help resolve this. Changes to infection prevention practice should be supported by evidence showing that cost-effectiveness is plausible and likely.

AIM

To perform a cost-effectiveness evaluation of adopting temporary single rooms into UK National Health Service (NHS) hospitals.

METHODS

The cost-effectiveness of a decision to adopt a temporary, single-patient, isolation room to the current infection prevention efforts of an NHS hospital was modelled. Primary outcomes are the expected change to total costs and life-years from an NHS perspective.

FINDINGS

The mean expected incremental cost per life-year gained (LYG) is £5,829. The probability that adoption is cost-effective against a £20,000 threshold per additional LYG is 93%, and for a £13,000 threshold the probability is 87%. The conclusions are robust to scenarios for key model parameters. If a temporary single-patient isolation room reduces risks of HAI by 16.5% then an adoption decision is more likely to be cost-effective than not. Our estimate of the effectiveness reflects guidelines and reasonable assumptions and the theoretical rationale is strong.

CONCLUSION

Despite uncertainties about the effectiveness of temporary isolation rooms for reducing risks of HAI, there is some evidence that an adoption decision is likely to be cost-effective for the NHS setting. Prospective studies will be useful to reduce this source of uncertainty.

Chemotherapeutic Strategies for Combating Staphylococcus aureus Infections

Staphylococcus aureus is a prominent human pathogen that causes nosocomial and community acquired infections. The accelerating emergence and prevalence of staphylococcal infections have grotesque health consequences which are mostly due to its anomalous capability to acquire drug resistance and scarcity of novel classes of antibacterials. Many combating therapies are centered on primary targets of S. aureus which are cell envelope, ribosomes and nucleic acids. This review describes various chemotherapeutic strategies for combating S. aureus infections which includes monotherapy, combination drug therapy, phage endolysin therapy, lysostaphins and antibacterial drones. Monotherapy has dwindled in due course of time but combination therapy, endolysin therapy, lysostaphin and antibacterial drones are emerging alternatives which efficiently conquer the shortcomings of monotherapy. Combinations of more than one antibiotic agents or combination of adjuvant with antibiotics provide a synergistic approach to combat infections causing pathogenic strains. Phage endolysin therapy and lysostaphin are also presents as possible alternatives to conventional antibiotic therapies. Antibacterial Drones goes a step further by specifically targeting the virulence genes in bacteria giving them a certain advantage over existing antibacterial strategies. But the challenge remains on the better understanding of these strategies for executing and implementing them in health sector. In this day and age, most of the S. aureus strains are resistant to ample number of antibiotics, so there is an urgent need to overcome such multidrug resistant strains for the welfare of our community.

Reorganization of nurse scheduling reduces the risk of healthcare associated infections

Efficient prevention and control of healthcare associated infections (HAIs) is still an open problem. Using contact data from wearable sensors at a short-stay geriatric ward, we propose a proof-of-concept modeling study that reorganizes nurse schedules for efficient infection control. This strategy switches and reassigns nurses’ tasks through the optimization of shift timelines, while respecting feasibility constraints and satisfying patient-care requirements. Through a Susceptible-Colonized-Susceptible transmission model, we found that schedules reorganization reduced HAI risk by 27% (95% confidence interval [24, 29]%) while preserving timeliness, number, and duration of contacts. More than 30% nurse-nurse contacts should be avoided to achieve an equivalent reduction through simple contact removal. Nurse scheduling can be reorganized to break potential chains of transmission and substantially limit HAI risk, while ensuring the timeliness and quality of healthcare services. This calls for including optimization of nurse scheduling practices in programs for infection control in hospitals.

Comparison of PCR and phenotypic methods for the detection of methicillin resistant Staphylococcus aureus

Background and Objectives:

Resistance to methicillin in methicillin resistant strains of Staphylococcus aureus (MRSA) is due to the presence of mec-A gene, which encodes a low affinity penicillin binding protein (PBP)-2a or PBP2. Accurate and rapid identification of MRSA in clinical specimens is essential for timely decision on effective treatment. The aim of the study was to compare three different methods for detection of MRSA namely cefoxitin disc diffusion, CHROM agar MRSA and VITEK-2 susceptibility with PCR which is the gold standard reference method and to find the antibiotic susceptibility pattern of these isolates by VITEK-2.

Materials and Methods:

A Total of 100 non-duplicate S. aureus isolates were collected from different clinical samples among both outpatient and inpatients. Detection of MRSA among these isolates was done by cefoxitin disc diffusion, VITEK-2, CHROM agar MRSA and PCR.

Results:

The sensitivity and specificity of cefoxitin disc diffusion and Vitek was found to be 97.2% and 100%, while that of CHROM agar was found to be 100% and 78.6%. The overall prevalence of MRSA in our study by PCR was 72%.

Conclusion:

Based on the findings in our study, isolates which show cefoxitin zone diameter < 22 mm can be reported as MRSA. However, those isolates which have a zone diameter between 22–24 mm, should ideally be confirmed by PCR.

Determining the ideal prevention strategy for multidrug-resistance organisms in resource-limited countries: a cost-effectiveness analysis study

The aim of this study was to determine the most cost-effective strategy for the prevention and control of multidrug-resistant organisms (MDROs) in intensive care units (ICUs) in areas with limited health resources. The study was conducted in 12 ICUs of four hospitals. The total cost for the prevention of MDROs and the secondary attack rate (SAR) of MDROs for each strategy were collected retrospectively from 2046 subjects from January to December 2017. The average cost-effectiveness ratio (CER), incremental cost-effectiveness ratio (ICER) and cost-effectiveness acceptability curve were calculated. Hand hygiene (HH) had the lowest total cost (2149.6 RMB) and SAR of MDROs (8.8%) while single-room isolation showed the highest cost (33 700.2 RMB) and contact isolation had the highest SAR of MDROs (31.8%). The average cost per unit infection prevention was 24 427.8 RMB, with the HH strategy followed by the environment disinfection strategy (CER = 21 314.67). HH had the highest iterative cost effect under willingness to pay less than 2000 RMB. Due to the low cost for repeatability and obvious effectiveness, we conclude that HH is the optimal strategy for MDROs infections in ICUs in developing countries. The cost-effectiveness of the four prevention strategies provides some reference for developing countries but multiple strategies remain to be examined.

Knowledge, attitude, and practice of health care workers towards antibiotic resistance and antimicrobial stewardship programmes: A cross-sectional study

RATIONALE AND AIMS

Antibiotic development was a major breakthrough in defeating infections; however, their vast use has led to antimicrobial resistance (AMR) causing mortality, morbidity, and financial burden worldwide. Considering the limited introduction of newer antimicrobials to overcome resistance patterns, sufficient knowledge of their use can help manage this issue. Antimicrobial stewardship programmes (ASPs) with the mainstay of education can be a good resolution. The aim of this study was to seek aspects in which knowledge regarding antibiotics is lacking at our institutions.

MATERIALS AND METHODS

This cross-sectional study performed in Shiraz, South of Iran, was designed as a knowledge, attitude, and practice (KAP) study. A self-administered questionnaire consisting of 15 questions was designed and handed out to health care workers including infectious disease practitioners, surgeons, internal medicine specialists and residents, general practitioners, medical students, and microbiology lab technicians and PhD graduates. Difference in response to questions was evaluated between the practitioner and nonpractitioner groups.

RESULTS

Completed questionnaires were collected (n = 126). According to the results, most participants (88.1%) agreed on establishment of local guidelines. Majority (94.4%) also believed that education regarding antibiotics can help reduce AMR. Good patient care was not believed to be impaired by limiting use of antibiotics (72.2%). A significant difference in the practitioner and nonpractitioner groups' practice score was observed.

CONCLUSION

In our study, knowledge deficit was observed in some aspects of AMR. We can conclude that more practice and education are needed in ASP for the better performance in reducing resistant patterns.

Patient care experience with utilization of isolation precautions: systematic literature review and meta-analysis

BACKGROUND

Use of isolation precautions (IP) may represent a trade-off between reduced transmission of infectious pathogens and reduced patient satisfaction with their care.

OBJECTIVE

To perform a systematic literature review and meta-analysis to identify if and how IPs impact patients' care experiences.

DATA SOURCES

Medline, ClinicalTrials.gov, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, PsychInfo, HSRProj and Cochrane Library databases.

STUDY ELIGIBILITY CRITERIA

Interventional and observational studies published January 1990 to May 2019 were eligible for inclusion.

PARTICIPANTS

Patients admitted to an acute-care facility.

INTERVENTIONS

IPs versus no IPs.

METHODS

Six reviewers screened titles, abstracts and full text. Experience of care reported by patients using the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey was assessed as the outcome for the meta-analysis. Pooled odds ratios were calculated using the random-effects model. Heterogeneity was assessed using the I² value.

RESULTS

After screening 7073 titles and abstracts, 15 independent studies were included in the review. Pooling of unadjusted estimates from the HCAHPS survey demonstrated that IP patients were less likely to give top scores on questions pertaining to respect, communication, receiving assistance and cleanliness compared to the no-IP patients. Patients under IP with longer length of stay appeared to have more negative experiences with the care received during their stay compared to no IP.

CONCLUSIONS

Patients under IP were more likely to be dissatisfied with several aspects of patient care compared to patients not under IP. It is crucial to educate patients and healthcare workers in order to balance successful implementation of IP and patient care experiences, particularly in healthcare settings where it may be beneficial.

Analysis of network interventions with an application to hospital-acquired infections

Regional interventions to prevent the spread of hospital-acquired infections, vaccination campaigns, and information dissemination strategies are examples of treatment interventions applied to members of a network with the intent of effecting a network-wide change. In designing clinical trials or determining policy changes, it may not be cost effective or otherwise possible to treat all actors of a network. There is a notable lack of study designs and statistical frameworks with which to plan a network-wide intervention in this context and analyze the resulting data. This paper builds off of the network autocorrelation model in order to provide such a framework for a pre-post study design. We derive key quantitative measures of the network-wide treatment effect, exact formulas for power analyses of these measures, and extensions for the context in which the network is unknown. As the treatment assignation is part of the network-wide treatment, we provide methods for determining the assignation which optimizes the overall treatment effect over all members of the network subject to any arbitrary set of implementation costs and cost constraint. We implement these methods on Clostridioides difficile data for the state of California, where the hospitals are linked through patient sharing.

Molecular detection and typing of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative staphylococci isolated from cattle, animal handlers, and their environment from Karnataka, Southern Province of India

Background and Aim:

Methicillin-resistant staphylococci are among the emerging pathogens which have become a threat to both human and animal health. The present investigation intended to examine the occurrence and the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS) recovered from cattle, its handlers, and their environment.

Materials and Methods:

A total of 666 specimens were subjected to culture method and genus-specific polymerase chain reaction (PCR) for the identification of Staphylococcus. Methicillin resistance was substantiated by PCR identification of mecA and mecC resistance determinants. Species-specific identification of mecA positive isolates was conducted by multiplex PCR. The unidentified species were deciphered by 16S rRNA gene sequencing approach. The mecA positive isolates were further characterized by staphylococcal cassette chromosome mec (SCCmec) typing and multilocus sequence typing (MLST).

Results:

Duplex PCR identified 728 Staphylococcus isolates, of which 66 (9%) were positive for mecA gene. MRSA constituted 24% of the total mecA positive isolates. Among MRCoNS, Staphylococcus epidermidis (42%), and Staphylococcus haemolyticus (11%) were the most common species identified. Overall, 47% of the mecA positive isolates belonged to SCCmec type V. MLST analysis showed eight different sequence types (STs) among MRSA isolates of which five were novel STs. Among methicillin-resistant S. epidermidis, 19 different STs were found, of which nine novel STs were detected.

Conclusion:

The increase in the prevalence of mecA positive staphylococci, especially MRCoNS in cattle is a great concern in view of their transmission potential. Hence, continuous monitoring and molecular characterization of methicillin-resistant staphylococci should be elucidated in human and animal sectors so as to prevent the spread of these resistant pathogens.

The Role of the Environment and Colonization in Healthcare-Associated Infections

Healthcare-associated infections (HAIs) can be caused by endogenous host microbial flora or by exogenous microbes, including those found in the hospital environment. Efforts to decrease endogenous pathogens via decolonization and skin antisepsis may decrease the risk of infection in some settings. Controlling the spread of potential pathogens from the environment requires meticulous attention to cleaning and disinfection practices. In addition to selection of the appropriate cleaning agent, use of tools that assess the adequacy of cleaning and addition of no-touch cleaning technology may decrease environmental contamination. Hand hygiene is also a critical component of preventing transmission of pathogens from the environment to patients via healthcare worker hands.

Determining the Biofilm Forming Gene Profile of Staphylococcus aureus Clinical Isolates via Multiplex Colony PCR Method

BACKGROUND

Among hospitalized patients, Staphylococcus aureus (S. aureus) infections pose a serious health threat. The present study investigated the frequency of biofilm forming genes among clinical isolates S. aureus and their susceptibility to antibiotics.

METHODS

The clinical samples were analyzed via standard biochemical assays for identifying different bacterium, which was then confirmed using the multiplex colony PCR method. Those samples identified as S. aureus were examined for the presence of the cna, fnbA, fnbB and pvl genes. The antibiotic susceptibility of the S. aureus isolates was then tested.

RESULTS

Using the standard biochemical assay approach, 54 S. aureus strains were identified. However, when using the multiplex PCR method 50 S. aureus strains were identified among the clinical samples. The in vitro biofilm formation assays determined 3 (6%) strains of S. aureus to be strong biofilm forming, 15 (30%) of the isolates were determined to be moderate biofilm forming and, 32 (64%) were determined to be weak biofilm forming. Among the isolated strains, the specific frequencies of the biofilm forming genes were determined to be 31 (62%) for cna, 35 (70%) for fnbA, 13 (26%) for fnbB and 1 (2%) for pvl. In 11 (22%) of the isolated strains fnbA, fnbB and cna genes were all present. All strains were determined to be penicillin, amoxicillin and clavulanic acid resistant.

CONCLUSION

Due to the increase of the antibiotic resistance in biofilm producing S. aureus strains, rapid identification of antibiotic resistance can help to eliminate the infection effectively.

Inference and control of the nosocomial transmission of methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a continued threat to human health in both community and healthcare settings. In hospitals, control efforts would benefit from accurate estimation of asymptomatic colonization and infection importation rates from the community. However, developing such estimates remains challenging due to limited observation of colonization and complicated transmission dynamics within hospitals and the community. Here, we develop an inference framework that can estimate these key quantities by combining statistical filtering techniques, an agent-based model, and real-world patient-to-patient contact networks, and use this framework to infer nosocomial transmission and infection importation over an outbreak spanning 6 years in 66 Swedish hospitals. In particular, we identify a small number of patients with disproportionately high risk of colonization. In retrospective control experiments, interventions targeted to these individuals yield a substantial improvement over heuristic strategies informed by number of contacts, length of stay and contact tracing.

A systematic review of transmission dynamic studies of methicillin-resistant Staphylococcus aureus in non-hospital residential facilities

BACKGROUND

Non-hospital residential facilities are important reservoirs for MRSA transmission. However, conclusions and public health implications drawn from the many mathematical models depicting nosocomial MRSA transmission may not be applicable to these settings. Therefore, we reviewed the MRSA transmission dynamics studies in defined non-hospital residential facilities to: (1) provide an overview of basic epidemiology which has been addressed; (2) identify future research direction; and (3) improve future model implementation.

METHODS

A review was conducted by searching related keywords in PUBMED without time restriction as well as internet searches via Google search engine. We included only articles describing the epidemiological transmission pathways of MRSA/community-associated MRSA within and between defined non-hospital residential settings.

RESULTS

Among the 10 included articles, nursing homes (NHs) and correctional facilities (CFs) were two settings considered most frequently. Importation of colonized residents was a plausible reason for MRSA outbreaks in NHs, where MRSA was endemic without strict infection control interventions. The importance of NHs over hospitals in increasing nosocomial MRSA prevalence was highlighted. Suggested interventions in NHs included: appropriate staffing level, screening and decolonizing, and hand hygiene. On the other hand, the small population amongst inmates in CFs has no effect on MRSA community transmission. Included models ranged from system-level compartmental models to agent-based models. There was no consensus over the course of disease progression in these models, which were mainly featured with NH residents /CF inmates/ hospital patients as transmission pathways. Some parameters used by these models were outdated or unfit.

CONCLUSIONS

Importance of NHs has been highlighted from these current studies addressing scattered aspects of MRSA epidemiology. However, the wide variety of non-hospital residential settings suggest that more work is needed before robust conclusions can be drawn. Learning from existing work for hospitals, we identified critical future research direction in this area from infection control, ecological and economic perspectives. From current model deficiencies, we suggest more transmission pathways be specified to depict MRSA transmission, and further empirical studies be stressed to support evidence-based mathematical models of MRSA in non-hospital facilities. Future models should be ready to cope with the aging population structure.

Assessing the reporting quality of influenza outbreaks in the community

BACKGROUND

High-quality reporting of outbreak characteristics is fundamental to understand the behaviour of various strains of influenza virus and the impact of outbreak management strategies. However, few studies have systematically evaluated the quality of outbreak reporting.

OBJECTIVES

To conduct a systematic analysis and assessment for reporting quality of influenza outbreaks based on a modified version of the STROBE statement, and to examine characteristics associated with reporting quality.

METHODS

A literature search was conducted across 3 online databases (PubMed, Web of Science, MEDLINE) for reports of influenza outbreaks (pandemic H1N1, avian, seasonal). The quality of reports meeting our eligibility criteria was assessed using the Modified STROBE criteria and assigned a score of 30. Mean differences (MD) and 95% confidence intervals (CI) were reported for comparisons of study characteristics.

RESULTS

Sixty-four outbreak reports were available for analyses. The average Modified STROBE score was 20/30. Peer-reviewed articles were associated with a better quality of reporting (MD 2.79, 95% CI 0.79-4.78). Likewise, reports from authors affiliated with public health agencies were associated with better quality than those from academic institutions (MD 1.65, 95% CI-0.27-3.56).

CONCLUSIONS

The development of explicit reporting guidelines specifically geared towards reporting of outbreak investigations proved to be useful. Providing information on patient characteristics, investigation details in introduction and results, as well as addressing limitations that could have biased the findings, were frequently missing in the published reports.

A review of antimicrobial stewardship training in medical education

OBJECTIVES

We reviewed the published literature on antimicrobial stewardship training in undergraduate and postgraduate medical education to determine which interventions have been implemented, the extent to which they have been evaluated, and to understand which are most effective.

METHODS

We searched Ovid MEDLINE and EMBASE from inception to December 2016. Four thousand three hundred eighty-five (4385) articles were identified and underwent title and abstract review. Only those articles that addressed antimicrobial stewardship interventions for medical trainees were included in the final review. We employed Kirkpatrick's four levels of evaluation (reaction, learning, behaviour, results) to categorize intervention evaluations.

RESULTS

Our review included 48 articles. The types of intervention varied widely amongst studies worldwide. Didactic teaching was used heavily in all settings, while student-specific feedback was used primarily in the postgraduate setting. The high-level evaluation was sparse, with 22.9% reporting a Kirkpatrick Level 3 evaluation; seventeen reported no evaluation. All but one article reported positive results from the intervention. No articles evaluated the impact of an intervention on undergraduate trainees' prescribing behaviour after graduation.

CONCLUSIONS

This study enhances our understanding of the extent of antimicrobial stewardship in the context of medical education. While our study demonstrates that medical schools are implementing antimicrobial stewardship interventions, rigorous evaluation of programs to determine whether such efforts are effective is lacking. We encourage more robust evaluation to establish effective, evidence-based approaches to training prescribers in light of the global challenge of antimicrobial resistance.

Impact of Discontinuing Contact Precautions for MRSA and ESBLE in an Intensive Care Unit: A Prospective Noninferiority Before and After Study

OBJECTIVE

To compare incidence densities of methicillin-resistant Staphylococcus aureus (MRSA) or extended-spectrum β-lactamase–producing Enterobacteriaceae (ESBLE) acquisition in the intensive care unit (ICU) before and after discontinuation of contact precautions (CP) and application of standard precautions (SP).

DESIGN

Prospective noninferiority before-and-after study comparing 2 periods: January 1, 2012, to January 31, 2014 (the CP period) and February 1, 2014, to February 29, 2016 (the SP period).

SETTING

A 16-bed polyvalent ICU in France with only single-bed rooms with dedicated equipment and reusable medical devices.

PATIENTS

All patients admitted to the ICU during the CP and SP periods were included: 1,547 and 1,577 patients, respectively.

METHODS

Incidence densities of ICU-acquired MRSA or ESBLE were determined per 1,000 patient days. Other studied factors included (1) patient characteristics, (2) incidence densities of MRSA or ESBLE carried at admission, (3) compliance with hand hygiene protocols, and (4) antibiotic consumption.

RESULTS

Incidence densities of ICU-acquired MRSA were 0.82 (95% confidence interval [CI], 0.31–1.33) and 0.79 (95% CI, 0.30–1.29) per 1,000 patient days during the CP and SP periods, respectively. For ESBLE, values were 2.7 (95% CI, 1.78–3.62) and 2.06 (95% CI, 1.27–2.86) per 1,000 patient days. These rates were significantly nonsuperior during the SP period compared to CP period, with a margin of 1 per 1,000 patient days for both MRSA (P=.002) and ESBLE (P=.004). Other factors were comparable during the 2 periods. Only ESBLE carried at admission was inferior during the SP period. We observed a high level of compliance to hand hygiene protocols.

CONCLUSIONS

Discontinuing CP did not increase acquired MRSA and ESBLE in our ICU with single rooms with dedicated equipment, strict application of hand hygiene, medical and paramedical leadership, and good antibiotic stewardship.

Infect Control Hosp Epidemiol 2017;38:1342–1350

Are Contact Precautions ethically justifiable in contemporary hospital care?

Hospital infection control practices known as Contact Precautions are recommended for the management of people with pathogens such as methicillin-resistant Staphylococcus aureus or vancomycin-resistant Enterococci. Background: The patient is isolated, and staff are required to wear gloves, and a gown or apron when providing care. A notice is displayed to remind staff of these requirements and an 'alert' message is placed in the patient's medical record. Objective: The aim of this article is to discuss and explore whether practices used in hospitals to reduce the transmission of endemic antibiotic-resistant organisms are ethically justified in today's healthcare environment in the developed world. In order to do this, the history of the development of these practices is summarised, and the evidence base for their effectiveness is reviewed. Key bioethics principles are then discussed and contextualised from the perspective of hospital infection prevention and control, and an ethically superior model for the prevention and control of healthcare associated infection is proposed.

Acquisition of Multidrug-Resistant Organisms Among Hospital Patients Hospitalized in Beds Adjacent to Critically Ill Patients

Objective.

To assess whether patients hospitalized in beds physically adjacent to critically ill patients are at increased risk to acquire multidrug-resistant pathogens.

Design.

Cohort study.

Setting.

Shaare Zedek Medical Center, a 550-bed medical referral center.

Patients.

From April to September 2004, we enrolled consecutive newly admitted patients who were hospitalized in beds adjacent to either mechanically ventilated patients or patients designated as “do not resuscitate” (DNR). For each of these patients, we also enrolled a control patient who was not hospitalized in a bed adjacent to a critically ill patient. We collected specimens from the anterior nares, the oral cavity, and the perianal zone at the time of admission and subsequently at 3-day intervals until discharge or death. Specimens were cultured on selective media to detect growth of antibiotic-resistant pathogens, includingAcinetobacter baumannii, methicillin-resistantStaphylococcus aureus(MRSA), extended-spectrum β lactamase (ESBL)–producing Enterobacteriaceae, and vancomycin-resistant enterococci (VRE).

Results.

We enrolled 46 neighbor-control pairs. Among neighbors and controls, respectively, the incidence rates for isolation ofA. baumanniiwas 8.3 and 4 isolations per 100 patient-days (relative risk [RR], 2.1 [95% confidence interval {CI}, 0.8-5.2];P= .12), the incidence rates for MRSA were 1.4 and 2.6 isolations per 100 patient-days (RR, 0.6 [95% CI, 0.1-2.3];P= .45), the incidence rates for ESBL-producing Enterobacteriaceae were 10.5 and 9 isolations per 100 patient-days (RR, 1.2 [95% CI, 0.6-2.4];P= .84), the incidence rates for VRE were 4.3 and 4.8 isolations per 100 patient-days (RR, 0.9 [95% CI, 0.3-2.4];P= 1), and the composite incidence rate was 21.7 and 16.2 isolations per 100 patient-days (RR, 1.3 [95% CI, 0.8-2.3];P= 0.3).

Conclusions.

In this pilot study, we did not detect an increased incidence rate of isolation of multidrug-resistant pathogens among patients hospitalized in beds adjacent to critically ill patients. Further studies with larger samples should be conducted in order to generate valid data and provide patients, physicians, and policy makers with a sufficient knowledge base from which decisions can be made.

Effects of Methicillin-Resistant Staphylococcus aureus/Multiresistant Gram-Negative Bacteria Colonization or Infection and Isolation Measures in End of Life on Family Caregivers: Results of a Qualitative Study

BACKGROUND

Little is known about the experiences of family caregivers of hospitalized patients with confirmed methicillin-resistant Staphylococcus aureus/multiresistant gram-negative bacteria (MRSA/MRGN) diagnosis at the end of life. The study at hand is a subproject of an interdisciplinary cooperation project that aims at developing a patient-, family-, and team-centered approach in dealing with MRSA/MRGN-positive hospitalized patients in palliative and geriatric care.

OBJECTIVES

The present study aimed to assess the individual effects of the patient's MRSA/MRGN colonization or infection and isolation measures on family caregivers.

DESIGN

Between April 2014 and September 2015, all known family caregivers associated with an MRSA/MRGN-positive patient from a palliative care unit, a hospital palliative care support team, and a geriatric ward were considered for study participation. A qualitative interview study with family caregivers and an additional focus group was conducted. Data were analyzed using the principles of Grounded Theory.

RESULTS

Family caregivers (N = 62) raised suggestions regarding the provision of information and communication on the MRSA/MRGN diagnosis and hygiene measures from staff members and the consistency of hygiene procedures. Family caregivers requested not to be stigmatized or being disadvantaged due to the MRSA/MRGN diagnosis of the patient, and they wished to receive psychosocial and emotional support.

CONCLUSIONS

Staff members and institutional stakeholders should be aware that family caregivers might be burdened and upset by positive MRSA/MRGN diagnosis and the required hygiene measures. The need for detailed and understandable information on MRSA/MRGN, adequate communication between staff members and family caregivers, and support for family caregivers should be of special attention in particular in end-of-life care.

MiBAlert-a new information tool to fight multidrug-resistant bacteria in the hospital setting

BACKGROUND

Although the timely isolation of patients is an essential intervention to limit spread of drug-resistant bacteria, information about the colonization status is often unavailable or lost when patients are readmitted or transferred between hospitals. Therefore, carriers of drug resistant bacteria are not recognized sufficiently early, and proper and timely isolation precautions are not taken. Consequently, resistant bacteria of public health concerns including vancomycin resistant enterococci (VRE) and methicillin resistant Staphylococcus aureus (MRSA) can spread epidemically. To ensure timely identification and proper isolation of such patients we developed an automatic real-time alert of carriers of drug resistant bacteria.

OBJECTIVES

The aim of this paper is to describe the system, called MiBAlert, and share the initial experiences in connection with an outbreak of VRE in the greater Copenhagen area (the Capital region), Denmark.

METHODS

We obtained data on cases of VRE from hospitals in Copenhagen during the period when the first version of MiBAlert was implemented and log-data on the use of MiBAlert. Furthermore, a survey was conducted among 88 staff members to investigate their experiences of MiBAlert.

RESULTS

The alert is a tool directed toward healthcare personnel accessing the electronic health record (EHR) and those further involved in the care and treatment of the patient. It is based on a web service using data from the national microbiological database, MiBa. MiBAlert is a real-time electronic non-intrusive alert generated automatically in the header of the EHR each time record is accessed. On February 15, 2015 a pilot version of MiBAlert was launched. All positive tests for VRE throughout 1year were shown with alert status by MiBAlert visible to all medical staff with access to EHR. The alert system was automatically updated directly in the EHR across the five hospitals in the Capital region. We found that the system performed satisfactorily, being operational 24/7 all 135 trial days, apart from 72min, for all the hospitals. Of the staff who responded to the survey, 82% considered that MiBAlert overall improved compliance with isolation precautions regarding VRE-positive patients. We found a marked decline of new patients infected or colonized with VRE concomitant with the implementation of MiBAlert and the survey results.

CONCLUSION

We found that MiBAlert was a valuable tool in a bundle approach to counter a multiple hospital outbreak of VRE, and that it has a great potential to improve the control of other drug-resistant bacteria.

Identifying conditions for elimination and epidemic potential of methicillin-resistant Staphylococcus aureus in nursing homes

BACKGROUND

Residents of nursing homes are commonly colonized with methicillin-resistant Staphylococcus aureus (MRSA) but there is a limited understanding of the dynamics and determinants of spread in this setting. To address this gap, we sought to use mathematical modeling to assess the epidemic potential of MRSA in nursing homes and to determine conditions under which non-USA300 and USA300 MRSA could be eliminated or reduced in the facilities.

METHODS

Model parameters were estimated from data generated during a longitudinal study of MRSA in 6 Wisconsin nursing homes. The data included subject colonization status with strain-specific MRSA collected every 3 months for up to 1 year. Deterministic and stochastic co-colonization and single-strain models were developed to describe strain-specific dynamics of MRSA in these facilities. Basic reproduction numbers of strain-independent MRSA, non-USA300 and USA300 MRSA were estimated numerically. The impact of antibiotic use in the past 3 months on the prevalence of strain-specific MRSA and associated basic reproduction numbers were evaluated.

RESULTS

Our models predicted that MRSA would persist in Wisconsin nursing homes, and non-USA300 would remain the dominant circulating strain. MRSA eradication was theoretically achievable by elimination of MRSA-positive admissions over the course of years. Substantial reductions in MRSA prevalence could be attained through marked increase in clearance rates or reduction in MRSA-positive admissions sustained over years. The basic reproduction number of strain-independent MRSA was 0.18 (95 % CI = 0.13-0.23). Recent antibiotic use increased the prevalence of strain-specific MRSA and associated basic reproduction numbers, but was unlikely to lead to an outbreak.

CONCLUSIONS

Based on our model, MRSA elimination from nursing homes, while theoretically possible, was unlikely to be achieved in practice. Decolonization therapy that can sustain higher clearance rates or lower MRSA-positive introductions over years may reduce strain-specific prevalence of MRSA in the facilities, and antibiotic stewardship may contribute to this effort. Large-scale MRSA outbreaks were unlikely in this setting.

Antibiotic treatment and resistance in chronic wounds of vascular origin

Background and aim

The problem of antibiotic resistance is worldwide and affects many types of pathogens. This phenomenon has been growing for decades and nowadays we are faced with a wide range of worrisome pathogens that are becoming resistant and many pathogens that may soon be untreatable. The aim of this study was to determine the resistance and antibiotic treatment in chronic wounds of vascular origin.

Methods

We performed a cross sectional study on a sample of patients with chronic vascular wounds, hospitalized between October 2014 and August 2015, in the Clinic of Vascular Surgery in Trakia Hospital Stara Zagora. The statistical analysis of data was descriptive, considering the p value of ≤0.05, the threshold of statistical significance.

Results

In the group of 110 patients, the significantly most frequent chronic wound (p<0.001) was peripheral arteriopathy (47.3%, CI95%: 38.19–56.54). Among 159 strains, 30% of patients having multiple etiology, the species most frequently isolated were Staphylococcus aureus, E.coli, Enterococcus faecalis, Pseudomonas aeruginosa and Proteus mirabilis with a significant predominance (p<0.05) of the Gram negative (55.1%). The spectrum of strains resistance included the Beta-lactams (36.4%, p<0.001), Macrolides (20%), Tetracyclines (9.1%), Aminoglycosides (8.2%) and Fluoroquinolones (4.5%).

Conclusions

Gram negative microorganisms were the main isolates in patients with vascular chronic wound. Significantly predominant was the resistance to the beta-lactam antibiotics.

What To Think If the Results of the National Institutes of Health Randomized Trial of Methicillin-ResistantStaphylococcus aureusand Vancomycin-ResistantEnterococcusControl Measures Are Negative (and Other Advice to Young Epidemiologists): A Review and an Au Revoir

The incidence of methicillin-resistantStaphylococcus aureus(MRSA) and vancomycin-resistantEnterococcus(VRE) infections continues to rise in National Nosocomial Infections Surveillance system hospitals, and these pathogens are reportedly causing more than 100,000 infections and many deaths each year in US healthcare facilities. This has led some to insist that control measures are now urgently needed, but several recent articles have suggested that isolation of patients does not work, is not needed, or is unsafe, or that a single cluster-randomized trial could be used to decide such matters. At least 101 studies have reported controlling MRSA infection and 38 have reported controlling VRE infection by means of active detection by surveillance culture and use of isolation for all colonized patients in healthcare settings where the pathogens are epidemic or endemic, in academic and nonacademic hospitals, and in acute care, intensive care, and long-term care settings. MRSA colonization and infection have been controlled to exceedingly low levels in multiple nations and in the state of Western Australia for decades by use of active detection and isolation. Studies suggesting problems with using such data to control MRSA colonization and infection have their own problems, which are discussed. Randomized trials are epidemiologic tools that can sometimes provide erroneous results, and they have not been considered necessary for studying isolation before it is used to control other important infections, such as tuberculosis, smallpox, and severe acute respiratory syndrome. No single epidemiologic study should be considered definitive. One should always weigh all available evidence. Infection with antibiotic-resistant pathogens such as MRSA and VRE is controllable to a low level by active detection and isolation of colonized and infected patients. Effective measures should be used to minimize the morbidity and mortality attributable to these largely preventable infections.

Extended-spectrum beta-lactamase--producing enterobacteriaceae in the intensive care unit: acquisition does not mean cross-transmission

Background

In intensive care unit (ICU), infection and colonization by resistant Gram-negative bacteria increase costs, length of stay and mortality. Extended-spectrum beta-lactamase − producing Enterobacteriaceae (ESBL-E) is a group of pathogens increasingly encountered in ICU setting. Conditions that promote ESBL-E acquisition are not completely understood. The increasing incidence of infections related to ESBL-E and the unsolved issues related to ESBL-E cross-transmission, prompted us to assess the rates of referred and acquired cases of ESBL-E in ICU and to assess patient-to-patient cross-transmission of ESBL-E using a multimodal microbiological analysis.

Methods

During a 5-month period, all patients admitted to a medical ICU were tested for ESBL-E carriage. A rectal swab was performed at admission and then twice a week until discharge or death. ESBL-E strains were analyzed according to antibiotic susceptibility pattern, rep-PCR (repetitive-element Polymerase chain reaction) chromosomal analysis, and plasmid PCR (Polymerase chain reaction) analysis of ESBL genes. Patient-to-patient transmission was deemed likely when 2 identical strains were found in 2 patients hospitalized simultaneously in the ICU.

Results

Among the 309 patients assessed for ESBL-E carriage on admission, 25 were found to carry ESBL-E (importation rate: 8 %). During follow-up, acquisition was observed among 19 of them (acquisition rate: 6.5 %). Using the multimodal microbiological approach, we found only one case of likely patient-to-patient ESBL-E transmission.

Conclusions

In unselected ICU patients, we found rather low rates of ESBL-E referred and acquired cases. Only 5 % of acquisitions appeared to be related to patient-to-patient transmission. These data highlight the importance of jointly analyzing phenotypic profile and molecular data to discriminate strains of ESBL-E.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1489-z) contains supplementary material, which is available to authorized users.

Patient Isolation Precautions: Are They Worth It?

Isolation precautions are intended to minimize pathogen transmission and reduce hospital-acquired infections. More recently, the effectiveness of isolation precautions has been questioned because of increasing evidence of risks. These putative downsides are divided into a quantifiable monetary cost (i.e., a literal cost to the system) and clinically important but less easily quantifiable costs (i.e., "costs" to the patient). The authors also briefly review deisolation and alternatives to isolation. The present review is not arguing against appropriate isolation or precautions, simply that the authors consider both risks and benefits and disseminate up-to-date information. Their patient-focused goal is to mitigate risks for those who truly need isolating and to end isolation as soon as it is safe and appropriate to do so.

Integrating Time-Varying and Ecological Exposures into Multivariate Analyses of Hospital-Acquired Infection Risk Factors: A Review and Demonstration

OBJECTIVES Hospital-acquired infections (HAIs) develop rapidly after brief and transient exposures, and ecological exposures are central to their etiology. However, many studies of HAIs risk do not correctly account for the timing of outcomes relative to exposures, and they ignore ecological factors. We aimed to describe statistical practice in the most cited HAI literature as it relates to these issues, and to demonstrate how to implement models that can be used to account for them. METHODS We conducted a literature search to identify 8 frequently cited articles having primary outcomes that were incident HAIs, were based on individual-level data, and used multivariate statistical methods. Next, using an inpatient cohort of incident Clostridium difficile infection (CDI), we compared 3 valid strategies for assessing risk factors for incident infection: a cohort study with time-fixed exposures, a cohort study with time-varying exposures, and a case-control study with time-varying exposures. RESULTS Of the 8 studies identified in the literature scan, 3 did not adjust for time-at-risk, 6 did not assess the timing of exposures in a time-window prior to outcome ascertainment, 6 did not include ecological covariates, and 6 did not account for the clustering of outcomes in time and space. Our 3 modeling strategies yielded similar risk-factor estimates for CDI risk. CONCLUSIONS Several common statistical methods can be used to augment standard regression methods to improve the identification of HAI risk factors. Infect.

Current Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus in Elderly French People: Troublesome Clones on the Horizon

Objective: In 2015, we conducted at 44 healthcare facilities (HCFs) and 21 nursing homes (NHs) a 3-month bloodstream infection (BSI) survey, and a 1-day prevalence study to determine the rate of carriage of methicillin-resistant Staphylococcus aureus (MRSA) in 891 patients and 470 residents. We investigated the molecular characteristics of the BSI-associated and colonizing MRSA isolates, and assessed cross-transmission using double-locus sequence typing and pulsed-field gel electrophoresis protocol.

Results: The incidence of MRSA-BSI was 0.040/1000 patient-days (19 cases). The prevalence of MRSA carriage was 4.2% in patients (n = 39) and 8.7% in residents (n = 41) (p < 0.001). BSI-associated and colonizing isolates were similar: none were PVL-positive; 86.9% belonged to clonal complexes 5 and 8; 93.9% were resistant to fluoroquinolones. The qacA/B gene was carried by 15.8% of the BSI-associated isolates [3/3 BSI cases in intensive care units (ICUs)], and 7.7% of the colonizing isolates in HCFs. Probable resident-to-resident transmission was identified in four NHs.

Conclusion: Despite generally reassuring results, we identified two key concerns. First, a worryingly high prevalence of the qacA/B gene in MRSA isolates. Antisepsis measures being crucial to prevent healthcare-associated infections, our findings raise questions about the potential risk associated with chlorhexidine use in qacA/B⁺ MRSA carriers, particularly in ICUs. Second, NHs are a weak link in MRSA control. MRSA spread was not controlled at several NHs; because of their frequent contact with the community, conditions are favorable for these NHs to serve as reservoirs of USA300 clone for local HCFs.

Review of a two-year methicillin-resistant Staphylococcus aureus screening program and cost-effectiveness analysis in Singapore

Background

Methicillin-resistant Staphylococcus aureus (MRSA) poses an increasingly large disease and economic burden worldwide. The effectiveness of screening programs in the tropics is poorly understood. The aims of this study are: (i) to analyze the factors affecting MRSA colonization at admission and acquisition during hospitalization and (ii) to evaluate the cost-effectiveness of a screening program which aims to control MRSA incidence during hospitalization.

Methods

We conducted a retrospective case–control study of patients admitted to the Communicable Disease Centre (CDC) in Singapore between Jan 2009 and Dec 2010 when there was an ongoing selective screening and isolation program. Risk factors contributing to MRSA colonization on admission and acquisition during hospital stay were evaluated using a logistic regression model. In addition, a cost-effectiveness analysis was conducted to determine the cost per disability-adjusted life year (DALY) averted due to implementing the screening and isolation program.

Results

The average prevalence rate of screened patients at admission and the average acquisition rate at discharge during the study period were 12.1 and 4.8 % respectively. Logistic regression models showed that older age (adjusted odds ratio (OR) 1.03, 95 % CI 1.02–1.04, p < 0.001) and dermatological conditions (adjusted OR 1.49, 95 % CI 1.11–1.20, p = 0.008) were independently associated with an increased risk of MRSA colonization at admission. Age (adjusted OR 1.02, 95 % CI 1.01–1.03, p = 0.002) and length of stay in hospital (adjusted OR 1.04, 95 % CI 1.03–1.06, p < 0.001) were independent factors associated with MRSA acquisition during hospitalization. The screening and isolation program reduced the acquisition rate by 1.6 % and was found to be cost saving. For the whole study period, the program cost US$129,916, while it offset hospitalization costs of US$103,869 and loss of productivity costs of US$50,453 with −400 $/DALY averted.

Discussion

This study is the first to our knowledge that evaluates the cost-effectiveness of screeningand isolation of MRSA patients in a tropical country. Another unique feature of the analysis is the evaluationof acquisition rates among specific types of patients (dermatological, HIV and infectious disease patients)and the comparison of the cost-effectiveness of screening and isolation between them.

Conclusions

Overall our results indicate high MRSA prevalence that can be cost effectively reduced by selective screening and isolation programs in Singapore.

Modelling the effect of antimicrobial treatment on carriage of hospital pathogens with application to MRSA

Numerous studies have sought to assess the effectiveness of control measures aimed at reducing the spread of pathogens such as Methicillin-resistant Staphylococcus aureus (MRSA) in hospital settings. Far less is known about possible short-term effects of antibiotics and other antimicrobial treatments on pathogen carriage in patients. This paper is concerned with developing and applying methods for the analysis of detailed data on hospital patients which include information on patient treatments and screening tests for the pathogen in question. The carriage status (colonized, or not) of each patient is modelled as a Markov chain, and models for both perfect and imperfect test sensitivity are developed. Goodness-of-fit procedures based on simulation are also proposed. The methods are illustrated using both simulated data and data on MRSA.

Effectiveness of contact precautions against multidrug-resistant organism transmission in acute care: a systematic review of the literature

Contact precautions are widely recommended to prevent multidrug-resistant organism (MDRO) transmission. However, conflicting data exist regarding their effectiveness. Prior systematic reviews examined contact precautions as part of a larger bundled approach, limiting ability to understand their effectiveness. The aim of this review was to characterize the effectiveness of contact precautions alone against transmission of any MDRO among adult acute care patients. Directed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, comprehensive searches of four electronic scientific literature databases were conducted for studies published in English from January 2004 to June 2014. Studies were included if interventional, original research, evaluating contact isolation precautions against MDRO transmission among inpatients. Searches returned 284 studies, six of which were included in the review. These studies measured four different MDROs with one study showing a reduction in transmission. Whereas studies were of high quality regarding outcome operationalization and statistical analyses, overall quality was moderate to low due to poor intervention description, population characterization and potential biases. Where compliance was measured (N = 4), it presented a threat to validity because it included select parts of the intervention, ranged from 21% to 87%, and was significantly different across study phases (N = 2). The poor quality of evidence on this topic continues to limit interpretation of these data. Hence, this conflicting body of literature does not constitute evidence for or against contact precautions. We recommend that researchers consider power calculation, compliance monitoring, non-equivalent concurrent controls when designing future studies on this topic.

French recommendations for the prevention of 'emerging extensively drug-resistant bacteria' (eXDR) cross-transmission

Controlling the spread of multi- or extensively drug-resistant bacteria (MDR or XDR) includes a dual strategy for reducing antibiotic prescriptions and preventing their spread from patient carriers. Standard precautions are applicable to all health professionals caring for any patients; additional barrier precautions (isolation) are recommended for patients carrying transmissible infectious diseases or MDR bacteria in sporadic or epidemic situations. Moreover, additional precautions may be required for populations at particular risk of infection or colonization by emerging XDR (eXDR), defined in our country as carbapenemase-producing Enterobacteriaceae and vancomycin-resistant enterococci. Our ability to detect and identify eXDR carriers early and ensure their follow-up, through effective communication between all those involved, is a significant challenge for controlling their spread. Thus, the French High Committee for Public Health has updated and standardized all French existing recommendations concerning the prevention of the cross-transmission of these bacteria, and these recommendations are summarized in this review. The recommendations are based on scientific and operational knowledge up to 2013. Different preventive strategies are recommended for patients found to be carrying eXDR and those who are considered to be at risk of having eXDR because of a history of contact. The local context, the experience of the infection control team, the different times at which detection of eXDR takes place (during admission, hospitalization, etc.) and the epidemiological situation (sporadic cases, clusters, outbreaks, widespread epidemic) must be included in risk assessments that in turn inform the control measures that should be applied in each clinical circumstance.

Is the prevalence of antibiotic-resistant organisms changing in Canadian hospitals? Comparison of point-prevalence survey results in 2010 and 2012

A national point-prevalence survey for infection or colonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), and for Clostridium difficile infection (CDI) was done in Canadian hospitals in 2010. A follow-up survey was done in November 2012 to determine whether there were any changes in the prevalence of these organisms; we also determined the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, and carbapenem-resistant Enterobacteriaceae (CREs). Associations between prevalence and infection prevention and control policies were evaluated in logistic regression models. A total of 143 (67% of eligible facilities) hospitals with 29 042 adult inpatients participated in the survey, with representation from all 10 provinces; 132 hospitals participated in 2010 and 2012. There were no significant changes in the median prevalence of MRSA in 2010 (4.3%) compared to 2012 (3.9%), or of CDI in 2010 (0.8%) compared to 2012 (0.9%). A higher median prevalence of VRE was identified in 2012 (1.3%) compared to 2010 (0.5%) (p 0.04), despite decreased VRE screening in 2012. The median prevalence of ESBLs was 0.7% and was 0 for CREs; CREs were reported from only 10 hospitals (7.0%). A policy of routinely caring for patients with MRSA or VRE in a private isolation room was associated with lower prevalence of these organisms. Targeted screening of high-risk patients at admission was associated with lower MRSA prevalence; better hand hygiene compliance was associated with lower VRE prevalence. These data provide national prevalence rates for antibiotic-resistant organisms among adults hospitalized in Canadian hospitals. Certain infection prevention and control policies were associated with prevalence.

Long-Term Control of Endemic Hospital-Wide Methicillin-ResistantStaphylococcus aureus(MRSA): The Impact of Targeted Active Surveillance for MRSA in Patients and Healthcare Workers

Objective.

To evaluate the long-term impact of successive interventions on rates of methicillin-resistantStaphylococcus aureus(MRSA) colonization or infection and MRSA bacteremia in an endemic hospital-wide situation.

Design.

Quasi-experimental, interrupted time-series analysis. The impact of the interventions was analyzed by use of segmented regression. Representative MRSA isolates were typed by use of pulsed-field gel electrophoresis.

Setting.

A 950-bed teaching hospital in Seville, Spain.

Patients.

All patients admitted to the hospital during the period from 1995 through 2008.

Methods.

Three successive interventions were studied: (1) contact precautions, with no active surveillance for MRSA; (2) targeted active surveillance for MRSA in patients and healthcare workers in specific wards, prioritized according to clinical epidemiology data; and (3) targeted active surveillance for MRSA in patients admitted from other medical centers.

Results.

Neither the preintervention rate of MRSA colonization or infection (0.56 cases per 1,000 patient-days [95% confidence interval {CI}, 0.49-0.62 cases per 1,000 patient-days]) nor the slope for the rate of MRSA colonization or infection changed significantly after the first intervention. The rate decreased significantly to 0.28 cases per 1,000 patient-days (95% CI, 0.17-0.40 cases per 1,000 patient-days) after the second intervention and to 0.07 cases per 1,000 patient-days (95% CI, 0.06-0.08 cases per 1,000 patient-days) after the third intervention, and the rate remained at a similar level for 8 years. The MRSA bacteremia rate decreased by 80%, whereas the rate of bacteremia due to methicillin-susceptibleS. aureusdid not change. Eighty-three percent of the MRSA isolates identified were clonally related. All MRSA isolates obtained from healthcare workers were clonally related to those recovered from patients who were in their care.

Conclusion.

Our data indicate that long-term control of endemic MRSA is feasible in tertiary care centers. The use of targeted active surveillance for MRSA in patients and healthcare workers in specific wards (identified by means of analysis of clinical epidemiology data) and the use of decolonization were key to the success of the program.

Implementation of an Industrial Systems-Engineering Approach to Reduce the Incidence of Methicillin-ResistantStaphylococcus aureusInfection

Objective.

To measure the effectiveness of an industrial systems-engineering approach to a methicillin-resistantStaphylococcus aureus(MRSA) prevention program.

Design.

Before-after intervention study

Setting.

An intensive care unit (ICU) and a surgical unit that was not an ICU in the Pittsburgh Veterans Administration hospital

Patients.

Allpatientsadmittedtothe study units

Intervention.

We implemented an MRSA infection control program that consisted of the following 4 elements: (1) the use of standard precautions for all patient contact, with emphasis on hand hygiene; (2) the use of contact precautions for interactions with patients known to be infected or colonized with MRSA; (3) the use of active surveillance cultures to identify patients who were asymptomatically colonized with MRSA; and (4) use of an industrial systems-engineering approach, the Toyota Production System, to facilitate consistent and reliable adherence to the infection control program.

Results.

The rate of healthcare-associated MRSA infection in the surgical unit decreased from 1.56 infections per 1,000 patient-days in the 2 years before the intervention to 0.63 infections per 1,000 patient-days in the 4 years after the intervention (a 60% reduction;P= .003). The rate of healthcare-associated MRSA infection in the ICU decreased from 5.45 infections per 1,000 patient-days in the 2 years before to the intervention to 1.35 infections per 1,000 patient-days in the 3 years after the intervention (a 75% reduction;P= .001). The combined estimate for reduction in the incidence of infection after the intervention in the 2 units was 68% (95% confidence interval, 50%-79%;P< .001).

Conclusions.

Sustained reduction in the incidence of MRSA infection is possible in a setting where this pathogen is endemic. An industrial systems-engineering approach can be adapted to facilitate consistent and reliable adherence to MRSA infection prevention practices in healthcare facilities.

Reduction in Hospitalwide Incidence of Infection or Colonization with Methicillin-ResistantStaphylococcus aureusWith Use of Antimicrobial Hand-Hygiene Gel and Statistical Process Control Charts

Objective.

To evaluate the impact of serial interventions on the incidence of methicillin-resistantStaphylococcus aureus(MRSA).

Design.

Longitudinal observational study before and after interventions.

Setting.

The Alfred Hospital is a 350-bed tertiary referral hospital with a 35-bed intensive care unit (ICU).

Interventions.

A series of interventions including the introduction of an antimicrobial hand-hygiene gel to the intensive care unit and a hospitalwide MRSA surveillance feedback program that used statistical process control charts but not active surveillance cultures.

Methods.

Serial interventions were introduced between January 2003 and May 2006. The incidence and rates of new patients colonized or infected with MRSA and episodes of MRSA bacteremia in the intensive care unit and hospitalwide were compared between the preintervention and intervention periods. Segmented regression analysis was used to calculate the percentage reduction in new patients with MRSA and in episodes of MRSA bacteremia hospitalwide in the intervention period.

Results.

The rate of new patients with MRSA in the ICU was 6.7 cases per 100 patient admissions in the intervention period, compared with 9.3 cases per 100 patient admissions in the preintervention period (P= .047). The hospitalwide rate of new patients with MRSA was 1.7 cases per 100 patient admissions in the intervention period, compared with 3.0 cases per 100 patient admissions in the preintervention period (P< .001). By use of segmented regression analysis, the maximum and conservative estimates for percentage reduction in the rate of new patients with MRSA were 79.5% and 42.0%, respectively, and the maximum and conservative estimates for percentage reduction in the rate of episodes of MRSA bacteremia were 87.4% and 39.0%, respectively.

Conclusion.

A sustained reduction in the number of new patients with MRSA colonization or infection has been demonstrated using minimal resources and a limited number of interventions.

The strength of coughing may forecast the likelihood of spread of multi-drug resistant microorganisms from the respiratory tract of colonized patients

Background

Current recommendations indicate that patients who are coughing and have multidrug resistant microorganisms (MDROs) in their sputum are considered to be shedders and should be cared for in single room isolation at least until symptoms resolve. Airborne spread and subsequent contamination of surfaces adjacent to patients may contribute to transmission. Hence, isolation measures for patients colonized or infected with MDRO at their respiratory tract are intended to interrupt such transmission. However, the potential for microbial shedding in patients with MDRO-positive microbiological reports from their respiratory tract and factors justifying the need for single room isolation are viewed controversially.

Methods

Cough aerosol produced by patients colonized with MDROs was measured for viable counts. Descriptive analysis together with logistic regression analysis was performed to assess the impact of strength of cough on growth of MDRO on culture plates.

Results

In 18% (23/128) MDRO were transmitted. Multivariate analysis revealed that strength of cough significantly predicts the yield of MDRO on culture plates (P = 0.012).

Conclusion

Based on these results it can be concluded that risk stratification for decision of single room isolation of patients colonized or infected with MDROs at their respiratory tract may also take the severity of cough into consideration. However, more work is required in order to assess the severity of cough objectively.

Preventing the introduction of meticillin-resistant Staphylococcus aureus into hospitals

The objective of this review was to provide an up-to-date account of the interventions used to prevent the introduction of meticillin-resistant Staphylococcus aureus (MRSA) from the expanding community and livestock reservoirs into hospitals in the USA, Denmark, The Netherlands and Western Australia. A review of existing literature and local guidelines for the management of MRSA in hospitals was performed. In Denmark, The Netherlands and Western Australia, where the prevalence of MRSA is relatively low, targeted admission screening and isolation of predefined high-risk populations have been used for several decades to successfully control MRSA in the hospital. Furthermore, in Denmark and The Netherlands, all identified MRSA carriers undergo routine decolonisation, whereas only carriers of particularly transmissible or virulent MRSA clones are subjected to decolonisation in Western Australia. In the USA, which continues to be a high-prevalence MRSA country, policies vary by state and even by hospital, and whilst guidelines from professional organisations provide a framework for infection control practices, these guidelines lack the authority of a legislative mandate. In conclusion, the changing epidemiology of MRSA, exemplified by the recent emergence of MRSA in the community and in food animals, makes it increasingly difficult to accurately identify specific high-risk groups to screen for MRSA carriage. Understanding the changing epidemiology of MRSA in a local as well as global context is fundamental to prevent the introduction of MRSA into hospitals.

Clinical, patient experience and cost impacts of performing active surveillance on known methicillin-resistant Staphylococcus aureus positive patients admitted to medical-surgical units

BACKGROUND

There is a large and growing body of evidence that methicillin-resistant Staphylococcus aureus (MRSA) screening programs are cost effective, but such screening represents a significant cost burden for hospitals. This study investigates the clinical, patient experience and cost impacts of performing active surveillance on known methicillin-resistant S aureus positive (MRSA+) patients admitted to 7 medical-surgical units of a large regional hospital, specifically to allow discontinuation of contact isolation.

METHODS

We conducted mixed-methods retrospective evaluation of a process improvement project that screened admitted patients with known MRSA+ status for continued MRSA colonization.

RESULTS

Of those eligible patients on our institution's MRSA+ list who did complete testing, 80.2% (130/162) were found to be no longer colonized, and only 19.8% (32/162) were still colonized. Forty-one percent (13/32) of interviewed patients in contact isolation for MRSA reported that isolation had affected their hospital stay, and 28% (9/32) of patients reported emotional distress resulting from their isolation. Total cost savings of the program are estimated at $101,230 per year across the 7 study units.

CONCLUSION

Our findings provide supporting evidence that a screening program targeting patients with a history of MRSA who would otherwise be placed in isolation has the potential to improve outcomes and patient experience and reduce costs.