Hospital-wide modification of fluoroquinolone policy and meticillin-resistant Staphylococcus aureus rates: a 10-year interrupted time-series analysis

Effects of a Primary Care Antimicrobial Stewardship Program on Meticillin-Resistant Staphylococcus aureus Strains across a Region of Catalunya (Spain) over 5 Years

Primary care antimicrobial stewardship program (ASP) interventions can reduce the over-prescription of unnecessary antibiotics, but the impact on the reduction in bacterial resistance is less known, and there is a lack of available data. We implemented a prolonged educational counseling ASP in a large regional outpatient setting to assess its feasibility and effectiveness. Over a 5-year post-implementation period, which was compared to a pre-intervention period, a significant reduction in antibiotic prescriptions occurred, particularly those associated with greater harmful effects and resistance selection. There was also a decrease in methicillin-resistant Staphylococcus aureus (MRSA) strains and in their co-resistance to other antibiotics, particularly those with an ecological impact.

The Extent of Antibiotic Dispensing in Self-Medication Encounters in Sudan: A Simulated Patient Study Focusing on Cefixime Sale

Background

Antibiotics play an important role in decreasing morbidity and mortality worldwide. However, inappropriate use of them by patients or healthcare professionals contributes to their resistance rendering them less efficacious. Community pharmacists (CPs) have a significant part in reducing antibiotic resistance. Therefore, this study aimed to investigate the dispensing of antibiotics without prescription in community pharmacies with an emphasis on cefixime dispensing.

Methods

A cross-sectional, simulated patient (SP) study was conducted in the Khartoum locality. A total of 238 community pharmacies were randomly chosen using simple random sampling. One scenario of uncomplicated urinary tract infection was designed, and six female pharmacy students who were trained to act as SPs presented the scenario. Descriptive statistics were applied to report the study outcomes.

Results

In the 238 pharmacy visits, at least one antibiotic was dispensed without a prescription in 69.3% of the simulated visits. Among the dispensed antibiotics, ciprofloxacin was the most dispensed antibiotic followed by cefixime representing 51.5% and 41.8%, respectively, of total dispensed antibiotics. Cefixime was dispensed as a first choice by CPs in 29% of the visits, and in the rest of the visits, only 37.3% of CPs refused to dispense cefixime after SP demand.

Conclusion

The findings revealed a high rate of antibiotics dispensing without prescription by CPs in Khartoum state, and cefixime was obtained with ease before and after the patient's demand. Urgent corrective actions such as imposing strict regulations, monitoring pharmacists' practice, and endorsing educational programs for pharmacists are needed to prevent inappropriate antibiotic dispensing practices.

[Antibiotic resistance - what can be done? A review]

Serious work is being carried out in the world in the field of combating antibiotic resistance: reducing the prescribing of antibiotics, banning the use of antibiotics as stimulators of animal growth, improving infection control. Antimicrobial resistance is systematically monitored not only in every medical center, but also at the national level. The collected data is successfully used to implement local and national recommendations on the optimal use of antibiotics.

Fluoroquinolone stewardship at a community health system: A decade in review

OBJECTIVE

To describe inpatient fluoroquinolone use and susceptibility data over a 10-year period after the implementation of an antimicrobial stewardship program (ASP) led by an infectious diseases pharmacist starting in 2011.

DESIGN

Retrospective surveillance study.

SETTING

Large community health system.

METHODS

Fluoroquinolone use was quantified by days of therapy (DOT) per 1,000 patient days (PD) and reported quarterly. Use data are reported for inpatients from 2016 to 2020. Levofloxacin susceptibility is reported for Pseudomonas aeruginosa and Escherichia coli for inpatients from 2011 to 2020 at a 4 adult-hospital health system.

RESULTS

Inpatient fluoroquinolone use decreased by 74% over a 5-year period, with an average decrease of 3.45 DOT per 1,000 PD per quarter (P < .001). Over a 10-year period, inpatient levofloxacin susceptibility increased by 57% for P. aeruginosa and by 15% for E. coli. P. aeruginosa susceptibility to levofloxacin increased by an average of 2.73% per year (P < .001) and had a strong negative correlation with fluoroquinolone use, r = -0.99 (P = .002). E. coli susceptibility to levofloxacin increased by an average of 1.33% per year (P < .001) and had a strong negative correlation with fluoroquinolone use, r = -0.95 (P = .015).

CONCLUSIONS

A substantial decrease in fluoroquinolone use and increase in P. aeruginosa and E. coli levofloxacin susceptibility was observed after implementation of an antimicrobial stewardship program. These results demonstrate the value of stewardship services and highlight the effectiveness of an infectious diseases pharmacist led antimicrobial stewardship program.

A Non-Restrictive Approach to Fluoroquinolone Stewardship at Two Community Hospitals

Background

Fluoroquinolones are one of the most prescribed antimicrobials in the United States and have been increasingly used in inpatient and outpatient settings to treat various infectious diseases syndromes. Due to the unwanted collateral effects on antibiotic resistance, poor susceptibility rates among Gram-negative pathogens, and adverse effects, fluoroquinolones are often targeted by hospital antimicrobial stewardship programs to prevent overutilization. This study describes the association of nonrestrictive antimicrobial stewardship interventions at 2 nonacademic community hospitals on levofloxacin utilization, prescribing patterns on alternative antibiotics, and Pseudomonas aeruginosa nonsusceptibility rates to levofloxacin.

Methods

Nonrestrictive antimicrobial stewardship interventions included monitoring and reporting of fluoroquinolone susceptibility trends to physician groups, performing medication use evaluations of levofloxacin accompanied with prescriber detailing, daily prospective audit and feedback, implementation of beta-lactam-based institutional guidelines for empiric therapy in various infectious disease syndromes, review and adjustment of electronic medical record order sets containing fluoroquinolones, and intensive prescriber education. No preauthorization of levofloxacin was used during this study period. Antibiotic utilization data were collected for the time periods of August 2015 through January 2021. Correlation between levofloxacin and other broad-spectrum antibiotc use was investigated as well as the impact on Pseudomonas aeruginosa levofloxacin nonsusceptibility rates.

Results

Both hospitals showed an overall downward trend in the prescribing of levofloxacin during the time period of August 2015 to January 2021. There was a significant negative correlation between monthly ceftriaxone and levofloxacin days of therapy for both hospitals (P < .0001). There was a positive correlation between levofloxacin days of therapy and P aeruginosa nonsusceptibility (P < .02 at both hospitals).

Conclusions

Our results demonstrate that a nonrestrictive approach to fluoroquinolone stewardship interventions had a significant impact on reducing levofloxacin utilization, increasing ceftriaxone utilization, and improving P aeruginosa levofloxacin susceptibility.

Effectiveness of an enhanced antibiotic stewardship programme amongst paediatric patients in a tertiary hospital in Vietnam

BACKGROUND

In 2016, the Vietnamese Ministry of Health promoted development of antimicrobial stewardship for hospitals.

AIM

To evaluate the effectiveness and safety of the enhanced antibiotic stewardship programme (ASP) compared to the original ASP amongst paediatric patients at a tertiary hospital for infectious diseases in Vietnam.

METHODS

We conducted an interrupted time series analysis to examine antibiotic use in paediatric patients aged 0 to 17 years admitted to the Hospital for Tropical Diseases in Ho Chi Minh City from April 2016 to March 2020. Outcomes measured were defined daily doses (DDDs) per 1000 patient-days; antibiotic days of therapy (DOT) per 1000 patient-days; percentage of antibiotic use by the WHO Access, Watch, and Reserve (AWaRe) system; Access-to-Watch ratio; and worse clinical outcomes at discharge.

FINDINGS

Of 60,172 admissions during the study period, 28,019 received at least one antibiotic (46.6%) during hospital stay. The Watch antibiotics were the most commonly prescribed (78.1% of total antibiotic courses). The enhanced ASP did not improve antibiotic prescribing by DDDs per 1000 patient-days (RR: 1.05, 95%CI: 0.94-1.17) and DOT per 1000 patient-days (RR: 1.11, 95%CI: 0.99-1.25) compared to the original ASP. However, the percentage of Access antibiotics prescribed, and the Access-to-Watch ratio increased after the enhanced ASP (RR: 1.73, 95%CI: 1.38-2.17). There was no significant difference in worse clinical outcomes at discharge between the original and enhanced ASP (RR: 1.25, 95%CI: 0.78-2.00).

CONCLUSION

The enhanced ASP had modest impact on antibiotic consumption in paediatric population despite the improvement of Access antibiotic use and the Access-to-Watch ratio.

Save the Quinolones! Impact of a Non-Restrictive Fluoroquinolone Reduction Initiative on Antibiotic Use and Resistance at an Urban Teaching Hospital

BACKGROUND

Many antibiotic stewardship programs have sought to reduce fluoroquinolone use due to their association with a myriad of negative consequences. In hospital settings with fewer resources, initiatives that are less labor intensive may offer a more feasible approach to addressing fluoroquinolone use and improving patient care.

OBJECTIVE

This study assessed the impact of a non-restrictive fluoroquinolone reduction initiative on antibiotic use and resistance.

METHODS

This was a retrospective pre- and post-interventional ecological study conducted from 2016 to 2017. The fluoroquinolone reduction initiative consisted of education on risks and alternatives. Buttons promoting "Save the Quinolones" were also worn to increase visibility. Outcome measures were the rate of fluoroquinolone use and antibiotic resistance in Staphylococcus aureus, Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, and Pseudomonas aeruginosa before and after the intervention.

RESULTS

Overall, fluoroquinolone use decreased throughout the study, but there was a significantly greater rate of decrease in the post-intervention period (monthly decrease of 3.3% (1.3, 5.1) v. 7.4% (5, 9.8) p = 0.043). S. aureus susceptibility to oxacillin increased from 47.2% to 55.2% (difference 8.0, 95%CI 1.2 to 14.7). P. aeruginosa susceptibility to levofloxacin increased from 60% to 70.7% (difference 10.7, 95%CI 0.8 to 20.6). No differences in susceptibility rates of E. coli, P. mirabilis or K. pneumoniae were detected.

CONCLUSION

This non-restrictive fluoroquinolone reduction initiative led to a significant decrease in fluoroquinolone use that was associated with decreased antibiotic resistance in S. aureus and P. aeruginosa.

A Simulated Client Exploration of Nonprescription Dispensing of Antibiotics at Drugstores for Pediatric Acute Diarrhea and Upper Respiratory Infection in Lahore, Pakistan

INTRODUCTION

The excessive consumption of antibiotics is a significant contributor to antimicrobial resistance, especially in children. Children are often advised antibiotics for viral infections. In developing countries, drugstores are a prime source of easy access to nonprescription antibiotics. Moreover, in Pakistan, their irrational use is an "everyday routine". The study, therefore, aimed to evaluate the dispensing of nonprescription antibiotics to children.

METHODS

Using pediatric acute diarrhea and acute upper respiratory infection as disease scenarios, a simulated client, cross-sectional study was conducted in Lahore, Pakistan, to explore the antibiotics' ease of availability at both categories of drugstores (pharmacies and medical stores) from November 1st, 2019 to January 31st, 2020. Chi-square (χ 2) test was used to compare the differences in practices of different categorical variables. Multivariable logistic regression was applied to analyze the association of various factors with antibiotics dispensing.

RESULTS

Antibiotics were dispensed without prescription in 456 (59%) of 773 simulated visits out of which 425 (93.2%) were dispensed on the advice of the drugstore staff. A qualified pharmacist was available in only 164 (21.2%) cases. Of the 386 visits for acute diarrhea and 387 for acute upper respiratory infection, nonprescription antibiotic dispensing occurred in 259 (67.1%) and 197 (50.9%) visits, respectively. There were considerable differences (p-value <0.05) in the practices and antibiotics dispensing between each disease scenario presented. Moreover, antibiotics were less commonly dispensed at pharmacist-supervised drugstores compared to unsupervised ones.

CONCLUSION

Overall, inappropriate dispensing practices were prevalent to a large extent at the drugstores, and antibiotics were effortlessly obtainable without prescription. The quality of the services provided, especially by the non-pharmacist staff, was also not satisfactory. Therefore, the Drug Regulating Authority of Pakistan must enforce strict implementation of drug laws at the drugstores without delay, especially in major cities to help curb the felonious use of antibiotics.

Review of antimicrobial resistance control strategies: low impact of prospective audit with feedback on bacterial antibiotic resistance within hospital settings

BACKGROUND

Antimicrobial stewardship constitutes an essential element of any concerted effort to tackle bacterial resistance, a rising public health threat both in community as well as hospital settings. The term comprises variable strategies which aim to optimise prescribing practices through either antibiotic restrictions or prospective audits of prescriptions with subsequent feedback to clinicians. Although highly debated, the actual effects of the latter on the antimicrobial susceptibility patterns of hospital flora are uncertain. The present study aims to review and evaluate the literature concerning the impact of persuasive stewardship strategies on antimicrobial resistance within hospitals.

MATERIALS AND METHODS

A literature review covering the period to 1st April 2020 was conducted using the PubMed/Medline, Embase, Global Health and CINAHL Plus databases.

RESULTS

Fifteen studies were retrieved, including twelve simple before-and-after, and three interrupted time-series studies. Audit frequency and compliance rates varied broadly. The rationale of treatment optimisation is not clear in most cases. Overall, surveillance of sentinel microorganisms through antibiograms indicates ambiguous results, with uncertainty as to whether the few successes are due to a causal effect, random incidence fluctuations, or confounding. The most informative approach targeted solely fluoroquinolones, reporting improvements in relevant Pseudomonas susceptibilities and MRSA, but without sufficient data on other effects of the strategy to assess its overall utility in clinical practice.

CONCLUSION

Higher standard research is needed to address the actual effects of persuasive stewardship strategies on antimicrobial susceptibility patterns. At present, they seem inadequate to play a decisive role in bacterial resistance control within hospitals.

Applied phyloepidemiology: Detecting drivers of pathogen transmission from genomic signatures using density measures

Understanding the driving forces of an epidemic is key to inform intervention strategies against it. Correlating measures of the epidemic success of a pathogen with ancillary parameters such as its drug resistance profile provides a flexible tool to identify such driving forces. The recently described time‐scaled haplotypic density (THD) method facilitates the inference of a pathogen's epidemic success from genetic data. Contrary to demogenetic approaches that define success in an aggregated fashion, the THD computes an independent index of success for each isolate in a collection. Modeling this index using multivariate regression, thus, allows us to control for various sources of bias and to identify independent predictors of success. We illustrate the use of THD to address key questions regarding three exemplary epidemics of multidrug‐resistant (MDR) bacterial lineages, namely Mycobacterium tuberculosis Beijing, Salmonella Typhi H58, and Staphylococcus aureus ST8 (including ST8‐USA300 MRSA), based on previously published, international genetic datasets. In each case, THD analysis allowed to identify the impact, or lack thereof, of various factors on the epidemic success, independent of confounding by population structure and geographic distribution. Our results suggest that rifampicin resistance drives the MDR Beijing epidemic and that fluoroquinolone resistance drives the S. aureus ST8/USA300 epidemic, in line with previous evidence of a lack of resistance‐associated fitness cost in these pathogens. Conversely, fluoroquinolone resistance measurably hampered the success of S. Typhi H58 and non‐H58. These findings illustrate how THD can help leverage the massive genomic datasets generated by molecular epidemiology studies to address new questions. THD implementation for the R platform is available at https://github.com/rasigadelab/thd.

Antimicrobial use among adult inpatients at hospital sites within the Canadian Nosocomial Infection Surveillance Program: 2009 to 2016

BACKGROUND

Antimicrobial resistance is a growing threat to the world's ability to prevent and treat infections. Links between quantitative antibiotic use and the emergence of bacterial resistance are well documented. This study presents benchmark antimicrobial use (AMU) rates for inpatient adult populations in acute-care hospitals across Canada.

METHODS

In this retrospective surveillance study, acute-care adult hospitals participating in the Canadian Nosocomial Infection Surveillance Program (CNISP) submitted annual AMU data on all systemic antimicrobials from 2009 to 2016. Information specific to intensive care units (ICUs) and non-ICU wards were available for 2014-2016. Data were analyzed using defined daily doses (DDD) per 1000 patient days (DDD/1000pd).

RESULTS

Between 2009 and 2016, 16-18 CNISP adult hospitals participated each year and provided their AMU data (22 hospitals participated in ≥1 year of surveillance; 11 in all years). From 2009 to 2016, there was a significant reduction in use (12%) (from 654 to 573 DDD/1000pd, p = 0.03). Fluoroquinolones accounted for the majority of this decrease (47% reduction in combined oral and intravenous use, from 129 to 68 DDD/1000pd, p < 0.002). The top five antimicrobials used in 2016 were cefazolin (78 DDD/1000pd), piperacillin-tazobactam (53 DDD/1000pd), ceftriaxone (49 DDD/1000pd), vancomycin (combined oral and intravenous use was 44 DDD/1000pd; 7% of vancomycin use was oral), and ciprofloxacin (combined oral and intravenous use: 42 DDD/1000pd). Among the top 10 antimicrobials used in 2016, ciprofloxacin and metronidazole use decreased significantly between 2009 and 2016 by 46% (p = 0.002) and 26% (p = 0.002) respectively. Ceftriaxone (85% increase, p = 0.0008) and oral amoxicillin-clavulanate (140% increase, p < 0.0001) use increased significantly but contributed only a small component (8.6 and 5.0%, respectively) of overall use.

CONCLUSIONS

This study represents the largest collection of dispensed antimicrobial use data among inpatients in Canada to date. Between 2009 and 2016, there was a significant 12% decrease in AMU, driven primarily by a 47% decrease in fluoroquinolone use. Modest absolute increases in parenteral ceftriaxone and oral amoxicillin-clavulanate use were noted but contributed a small amount of total AMU. Ongoing national surveillance is crucial for establishing benchmarks and antimicrobial stewardship guidelines.

Role of antimicrobial restrictions in bacterial resistance control: a systematic literature review

BACKGROUND

Antimicrobial stewardship is considered as one of the most fundamental aspects of bacterial resistance control. Among the multitude of initiatives, restrictive strategies have been widely practiced in hospital settings. However, data concerning their potential effectiveness have not been methodically collected and evaluated to date.

AIM

To identify, collect and evaluate the available evidence regarding the impact of restrictive policies on bacterial resistance in hospital settings.

METHODS

A systematic literature review was conducted using the PubMed/Medline, Embase, Global Health and CINAHL Plus databases.

FINDINGS

In total, 5555 papers were retrieved in the search process, and 29 studies were included in the final analysis. There were no randomized studies, and the inherent limitations of the observational designs employed impede the deduction of safe conclusions. Seemingly beneficial interventions encompass the restriction of broad-spectrum cephalosporins in favour of beta-lactam/lactamase inhibitor combinations as well as the restriction of fluoroquinolones. Antimicrobial restrictions might also play a role in the control of vancomycin-resistant enterococci, while carbapenem stewardship in the form of the preferred use of ertapenem did not produce the anticipated results. Complex restrictions are not offered for informative comparative analyses. Hospital-wide policies could perhaps be superior to those confined to high-risk departments. Carbapenem-resistant Acinetobacter baumannii might be difficult to control through solely formulary interventions.

CONCLUSION

The presumably effective restrictive strategies rely mainly on inadequately tested hypotheses and low-quality evidence. Therefore, systematic, high-quality research is needed to confirm and expand comprehension of the subject so that the most successful policies are employed in the field.

Antimicrobial overuse and misuse in the community in Greece and link to antimicrobial resistance using methicillin-resistant S. aureus as an example

Both antimicrobial consumption and antimicrobial resistance are very high in Greece, ranking among the highest of Europe. The link between antimicrobial consumption and resistance is well-known. Here, we discuss the reasons of antimicrobial overuse in Greece in the community (such as self-medication, dispersion of antibiotics by pharmacies without prescription, over-prescription by physicians, patient expectations and liability pressure) and we explore the misuse of antibiotics for common community infections. Furthermore, we discuss how such overuse/misuse can drive antimicrobial resistance, using methicillin-resistance in Staphylococcus aureus as an example. S. aureus is one of the pathogens with high rates of resistance in Greece. Comparing the rate of antimicrobial susceptibility to non-beta lactams between methicillin-resistant and methicillin-sensitive S. aureus we highlight the antibiotics that have the potential to drive methicillin-resistance through co-selection. Based on the above we identify targets for intervention in order to reduce antimicrobial overuse/misuse in the community in Greece.

Fluoroquinolone Restriction as an Effective Antimicrobial Stewardship Intervention

PURPOSE OF REVIEW

Fluoroquinolones are a commonly prescribed antibiotic class that has come under scrutiny in recent years due to mounting evidence of association between adverse drug events, C. difficile infection and isolation of antibiotic-resistant bacteria.

RECENT FINDINGS

Inpatient antimicrobial stewardship (AMS) programs have a toolbox of potential interventions to curb inappropriate antibiotic use, prevent antibiotic-associated adverse drug events, and avoid unnecessary costs of care. Fluoroquinolone restriction policies in the acute care setting have demonstrated beneficial effects, including decreased rates of C. difficile infection and ESBL-producing Enterobacteriaceae. However, a simple blanket restriction policy may "squeeze the antibiotic balloon" and will likely be insufficient if not implemented in conjunction with other AMS interventions. There is a growing body of evidence to support formulary restriction of fluoroquinolones in the acute care setting to decrease rates of C. difficile infection and development of ESBL-producing organisms. Data on how to best implement these restrictions or how to implement outside of acute care settings is limited.

Life After USA300: The Rise and Fall of a Superbug

The community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) epidemic in the United States is largely attributable to the meteoric rise of a single clone, referred to as USA300. This strain not only spread across the United States in just a few years to become the predominant cause of staphylococcal disease, but it also appears to have increased the overall number of skin and soft-tissue infections (SSTIs), increasing the overall disease burden. While USA300 still constitutes a major public health burden, its prevalence may be decreasing in some parts of the United States. Other than an epidemic in South America due to a closely related strain, USA300 also seems to have been largely unable to establish itself as an endemic infection in other geographic locations. While there have been several hypotheses put forward to explain the enormous success of USA300, the reasons for its failures and its potential fall remain obscure. Far from being unique to USA300, the rise and fall of specific clones of S. aureus in human populations seems to be a common process that has occurred multiple times and in multiple locations. This review charts the rise of USA300 and the evidence that suggests that it may be in decline, and it considers how best to understand the future spread, containment, and possible extinction of CA-MRSA.

The Impact of Antibiotic Stewardship Programs in Combating Quinolone Resistance: A Systematic Review and Recommendations for More Efficient Interventions

Quinolones are among the most commonly prescribed antibiotics worldwide. A clear relationship has been demonstrated between excessive quinolone use and the steady increase in the incidence of quinolone-resistant bacterial pathogens, both in hospital and community sites. In addition, exposure to quinolones has been associated with colonization and infection with healthcare-associated pathogens such as methicillin-resistant Staphylococcus aureus and Clostridium difficile in hospitalized patients. Therefore, the management of quinolone prescribing in hospitals through antibiotic stewardship programs is considered crucial. Although suggestions have been made by previous studies on the positive impact of stewardship programs concerning the emergence and spread of multidrug-resistant bacteria at hospital level, the association of quinolone-targeted interventions with reduction of quinolone resistance is vague. The purpose of this article was to evaluate the impact of stewardship interventions on quinolone resistance rates and healthcare-associated infections, through a literature review using systematic methods to identify and select the appropriate studies. Recommendations for improvements in quinolone-targeted stewardship programs are also proposed. Efforts in battling quinolone resistance should combine various interventions such as restriction formulary policies, prospective audits with feedback to prescribers, infection prevention and control measures, prompt detection of low-level resistance, educational programs, and guidelines for optimal quinolone usage. However, the effectiveness of such strategies should be assessed by properly designed and conducted clinical trials. Finally, novel approaches in diagnostic stewardship for rapidly detecting bacterial resistance, including PCR-based techniques, mass spectrometry, microarrays, and whole-genome sequencing as well as the prompt investigation on the clonality of quinolone-resistant strains, will strengthen our ability to personalize quinolone prescribing to individual patients.

Strategies to enhance rational use of antibiotics in hospital: a guideline by the German Society for Infectious Diseases

Introduction

In the time of increasing resistance and paucity of new drug development there is a growing need for strategies to enhance rational use of antibiotics in German and Austrian hospitals. An evidence-based guideline on recommendations for implementation of antibiotic stewardship (ABS) programmes was developed by the German Society for Infectious Diseases in association with the following societies, associations and institutions: German Society of Hospital Pharmacists, German Society for Hygiene and Microbiology, Paul Ehrlich Society for Chemotherapy, The Austrian Association of Hospital Pharmacists, Austrian Society for Infectious Diseases and Tropical Medicine, Austrian Society for Antimicrobial Chemotherapy, Robert Koch Institute.

Materials and methods

A structured literature research was performed in the databases EMBASE, BIOSIS, MEDLINE and The Cochrane Library from January 2006 to November 2010 with an update to April 2012 (MEDLINE and The Cochrane Library). The grading of recommendations in relation to their evidence is according to the AWMF Guidance Manual and Rules for Guideline Development.

Conclusion

The guideline provides the grounds for rational use of antibiotics in hospital to counteract antimicrobial resistance and to improve the quality of care of patients with infections by maximising clinical outcomes while minimising toxicity. Requirements for a successful implementation of ABS programmes as well as core and supplemental ABS strategies are outlined. The German version of the guideline was published by the German Association of the Scientific Medical Societies (AWMF) in December 2013.

Interventions to improve antibiotic prescribing practices for hospital inpatients

BACKGROUND

Antibiotic resistance is a major public health problem. Infections caused by multidrug-resistant bacteria are associated with prolonged hospital stay and death compared with infections caused by susceptible bacteria. Appropriate antibiotic use in hospitals should ensure effective treatment of patients with infection and reduce unnecessary prescriptions. We updated this systematic review to evaluate the impact of interventions to improve antibiotic prescribing to hospital inpatients.

OBJECTIVES

To estimate the effectiveness and safety of interventions to improve antibiotic prescribing to hospital inpatients and to investigate the effect of two intervention functions: restriction and enablement.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library), MEDLINE, and Embase. We searched for additional studies using the bibliographies of included articles and personal files. The last search from which records were evaluated and any studies identified incorporated into the review was January 2015.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and non-randomised studies (NRS). We included three non-randomised study designs to measure behavioural and clinical outcomes and analyse variation in the effects: non- randomised trials (NRT), controlled before-after (CBA) studies and interrupted time series (ITS) studies. For this update we also included three additional NRS designs (case control, cohort, and qualitative studies) to identify unintended consequences. Interventions included any professional or structural interventions as defined by the Cochrane Effective Practice and Organisation of Care Group. We defined restriction as 'using rules to reduce the opportunity to engage in the target behaviour (or increase the target behaviour by reducing the opportunity to engage in competing behaviours)'. We defined enablement as 'increasing means/reducing barriers to increase capability or opportunity'. The main comparison was between intervention and no intervention.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and assessed study risk of bias. We performed meta-analysis and meta-regression of RCTs and meta-regression of ITS studies. We classified behaviour change functions for all interventions in the review, including those studies in the previously published versions. We analysed dichotomous data with a risk difference (RD). We assessed certainty of evidence with GRADE criteria.

MAIN RESULTS

This review includes 221 studies (58 RCTs, and 163 NRS). Most studies were from North America (96) or Europe (87). The remaining studies were from Asia (19), South America (8), Australia (8), and the East Asia (3). Although 62% of RCTs were at a high risk of bias, the results for the main review outcomes were similar when we restricted the analysis to studies at low risk of bias.More hospital inpatients were treated according to antibiotic prescribing policy with the intervention compared with no intervention based on 29 RCTs of predominantly enablement interventions (RD 15%, 95% confidence interval (CI) 14% to 16%; 23,394 participants; high-certainty evidence). This represents an increase from 43% to 58% .There were high levels of heterogeneity of effect size but the direction consistently favoured intervention.The duration of antibiotic treatment decreased by 1.95 days (95% CI 2.22 to 1.67; 14 RCTs; 3318 participants; high-certainty evidence) from 11.0 days. Information from non-randomised studies showed interventions to be associated with improvement in prescribing according to antibiotic policy in routine clinical practice, with 70% of interventions being hospital-wide compared with 31% for RCTs. The risk of death was similar between intervention and control groups (11% in both arms), indicating that antibiotic use can likely be reduced without adversely affecting mortality (RD 0%, 95% CI -1% to 0%; 28 RCTs; 15,827 participants; moderate-certainty evidence). Antibiotic stewardship interventions probably reduce length of stay by 1.12 days (95% CI 0.7 to 1.54 days; 15 RCTs; 3834 participants; moderate-certainty evidence). One RCT and six NRS raised concerns that restrictive interventions may lead to delay in treatment and negative professional culture because of breakdown in communication and trust between infection specialists and clinical teams (low-certainty evidence).Both enablement and restriction were independently associated with increased compliance with antibiotic policies, and enablement enhanced the effect of restrictive interventions (high-certainty evidence). Enabling interventions that included feedback were probably more effective than those that did not (moderate-certainty evidence).There was very low-certainty evidence about the effect of the interventions on reducing Clostridium difficile infections (median -48.6%, interquartile range -80.7% to -19.2%; 7 studies). This was also the case for resistant gram-negative bacteria (median -12.9%, interquartile range -35.3% to 25.2%; 11 studies) and resistant gram-positive bacteria (median -19.3%, interquartile range -50.1% to +23.1%; 9 studies). There was too much variance in microbial outcomes to reliably assess the effect of change in antibiotic use. Heterogeneity of intervention effect on prescribing outcomesWe analysed effect modifiers in 29 RCTs and 91 ITS studies. Enablement and restriction were independently associated with a larger effect size (high-certainty evidence). Feedback was included in 4 (17%) of 23 RCTs and 20 (47%) of 43 ITS studies of enabling interventions and was associated with greater intervention effect. Enablement was included in 13 (45%) of 29 ITS studies with restrictive interventions and enhanced intervention effect.

AUTHORS' CONCLUSIONS

We found high-certainty evidence that interventions are effective in increasing compliance with antibiotic policy and reducing duration of antibiotic treatment. Lower use of antibiotics probably does not increase mortality and likely reduces length of stay. Additional trials comparing antibiotic stewardship with no intervention are unlikely to change our conclusions. Enablement consistently increased the effect of interventions, including those with a restrictive component. Although feedback further increased intervention effect, it was used in only a minority of enabling interventions. Interventions were successful in safely reducing unnecessary antibiotic use in hospitals, despite the fact that the majority did not use the most effective behaviour change techniques. Consequently, effective dissemination of our findings could have considerable health service and policy impact. Future research should instead focus on targeting treatment and assessing other measures of patient safety, assess different stewardship interventions, and explore the barriers and facilitators to implementation. More research is required on unintended consequences of restrictive interventions.

Architecture of a Species: Phylogenomics of Staphylococcus aureus

A deluge of whole-genome sequencing has begun to give insights into the patterns and processes of microbial evolution, but genome sequences have accrued in a haphazard manner, with biased sampling of natural variation that is driven largely by medical and epidemiological priorities. For instance, there is a strong bias for sequencing epidemic lineages of methicillin-resistant Staphylococcus aureus (MRSA) over sensitive isolates (methicillin-sensitive S. aureus: MSSA). As more diverse genomes are sequenced the emerging picture is of a highly subdivided species with a handful of relatively clonal groups (complexes) that, at any given moment, dominate in particular geographical regions. The establishment of hegemony of particular clones appears to be a dynamic process of successive waves of replacement of the previously dominant clone. Here we review the phylogenomic structure of a diverse range of S. aureus, including both MRSA and MSSA. We consider the utility of the concept of the 'core' genome and the impact of recombination and horizontal transfer. We argue that whole-genome surveillance of S. aureus populations could lead to better forecasting of antibiotic resistance and virulence of emerging clones, and a better understanding of the elusive biological factors that determine repeated strain replacement.

Dissimilar Fitness Associated with Resistance to Fluoroquinolones Influences Clonal Dynamics of Various Multiresistant Bacteria

Fitness cost associated with resistance to fluoroquinolones was recently shown to vary across clones of methicillin-resistant Staphylococcus aureus and extended-spectrum β-lactamase-producing Klebsiella pneumoniae. The resulting dissimilar fitness should have influenced the clonal dynamics and thereby the rates of resistance for these pathogens. Moreover, a similar mechanism was recently proposed for the emergence of the H30 and H30R lineages of ESBL-producing E. coli and the major international clone (ribotype 027) of Clostridium difficile. Furthermore, several additional international clones of various multiresistant bacteria are suspect to have been selected by an analogous process. An ability to develop favorable mutations in the gyrase and topoisomerase IV genes seems to be a prerequisite for pathogens to retain fitness while showing high-level resistance to fluoroquinolones. Since, the consumption of other "non-fluoroquinolone" groups of antibiotics have also contributed to the rise in resistance rates a more judicious use of antibiotics in general and of fluoroquinolones in particular could ameliorate the international resistance situation.

Impact of fluoroquinolones on human microbiota. Focus on the emergence of antibiotic resistance

The aggregate of microorganisms residing on the surface of the skin, in the oropharynx and in the GI tract, known as the human microbiota, play a major role as natural reservoirs for bacterial resistance to antibiotics. Fluoroquinolones (FQ) are among the most prescribed antibiotics and a major increase in FQ resistance is occurring worldwide. High concentrations of FQ are found in microbial ecosystems explaining their profound effect on the clinically relevant bacteria that compose them. Yet, because of different local pharmacokinetics, distinct selective pressures occur in the different microbiota. Here we review the qualitative and quantitative impact of FQ on the three main human microbiota and their consequences, particularly in terms of emergence of antibiotic resistance. Finally, we review potential actions that could decrease the impact of FQs on microbiota.

Long-term effects of an antimicrobial stewardship programme at a tertiary-care teaching hospital

Antimicrobial stewardship has been shown to reduce unnecessary antibiotic use, but there are few data on the long-term benefits of such a programme. Antimicrobial use over a 13-year period since implementing an antimicrobial stewardship programme (ASP) at our institution was examined. Nosocomial rates of Clostridium difficile infection (CDI) and antimicrobial susceptibility patterns of common nosocomial micro-organisms over the same period were also reviewed. Total antimicrobial use decreased by 62.8% (P<0.0001). There were decreases in use of aminoglycosides (-91.3%; P<0.0001), cephalosporins (-68.3%; P<0.0001), extended-spectrum penicillins (-77.7%; P<0.0001), macrolides (-27.2%; P=0.002), clindamycin (-95.9%; P<0.0001) and quinolones (-78.7%; P<0.0001). Antifungal use decreased by 71.0% (P<0.0001). There were increases in the use of carbapenems (+736%, P<0.0001) and anti-MRSA drugs (+73.3%; P<0.0001). There was a 56.7% (P=0.007) reduction in nosocomial MRSA infections. Nosocomial CDI rates decreased by 42.6% (P=0.005) between 2003 and 2010 and then increased to near baseline levels following implementation of more sensitive testing for detection of CDI in 2011. There were decreases in the rate (-71.9%; P=0.001) and percentage (-51.4%; P<0.0001) of quinolone-resistant Pseudomonas aeruginosa. There were decreases in the rate (P<0.0001) and percentage (P=0.02) of carbapenem-resistant P. aeruginosa following implementation of a policy restricting ciprofloxacin use. We have demonstrated sustained reductions in both antimicrobial use and drug-resistant organisms following implementation of an ASP.

Has the use of fluoroquinolones facilitated the widespread dissemination of methicillin-resistant Staphylococcus aureus and extended-spectrum β-lactamase-producing Klebsiella pneumoniae in the healthcare setting?

Our group recently demonstrated that diverse fitness cost associated with resistance to fluoroquinolones allowed the extensive dissemination of the major international clones of both methicillin-resistant Staphylococcus aureus (MRSA) and multiresistant Klebsiella pneumoniae in the healthcare setting. The mechanism described by us was subsequently confirmed by British authors investigating the dynamics of MRSA clones in England. Our results imply that the use of fluoroquinolones should impact the incidence for both MRSA and multiresistant K. pneumoniae. A review of the related clinical studies mostly support this notion and shows that changes in the consumption of fluoroquinolone type antibiotics and the rates for both MRSA and multiresistant ESBL-producing K. pneumoniae remain usually in accordance. Though the association seems strong and the mechanism behind it unequivocal the use of fluoroquinolones should not be abandoned; a more judicious application can be recommended.

Public health measures to control the spread of antimicrobial resistance in Neisseria gonorrhoeae in men who have sex with men

Gonorrhoea is one of the most common sexually transmitted infections. The control of gonorrhoea is extremely challenging because of the repeated development of resistance to the antibiotics used for its treatment. We explored different strategies to control the spread of antimicrobial resistance and prevent increases in gonorrhoea prevalence. We used a mathematical model that describes gonorrhoea transmission among men who have sex with men and distinguishes gonorrhoea strains sensitive or resistant to three antibiotics. We investigated the impact of combination therapy, switching first-line antibiotics according to resistance thresholds, and other control efforts (reduced sexual risk behaviour, increased treatment rate). Combination therapy can delay the spread of resistance better than using the 5% resistance threshold. Increased treatment rates, expected to enhance gonorrhoea control, may reduce gonorrhoea prevalence only in the short term, but could lead to more resistance and higher prevalence in the long term. Re-treatment of resistant cases with alternative antibiotics can substantially delay the spread of resistance. In conclusion, combination therapy and re-treatment of resistant cases with alternative antibiotics could be the most effective strategies to prevent increases in gonorrhoea prevalence due to antimicrobial resistance.

Epidemiological interpretation of studies examining the effect of antibiotic usage on resistance

Bacterial resistance to antibiotics is a growing clinical problem and public health threat. Antibiotic use is a known risk factor for the emergence of antibiotic resistance, but demonstrating the causal link between antibiotic use and resistance is challenging. This review describes different study designs for assessing the association between antibiotic use and resistance and discusses strengths and limitations of each. Approaches to measuring antibiotic use and antibiotic resistance are presented. Important methodological issues such as confounding, establishing temporality, and control group selection are examined.

Methicillin-resistant Staphylococcus aureus (MRSA) is increasing in Norway: a time series analysis of reported MRSA and methicillin-sensitive S. aureus cases, 1997-2010

BACKGROUND

Accurate estimates of the incidence and prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infections are needed to inform public health policies. In Norway, where both MRSA infection and carriage are notifiable conditions, the reported incidence of MRSA is slowly increasing. However, the proportion of MRSA in relation to all S. aureus isolates is unknown, making it difficult to determine if the rising incidence is real or an artifact of an increasing number of tests performed.

AIM

To characterize recent trends in MRSA infections and obtain a more complete understanding of the MRSA level in Norway.

METHODS

All reported cases of MRSA and methicillin-sensitive S. aureus (MSSA) from Oslo County (1997-2010) and Health Region East (2008-2008), representing approximately 11% and 36% of the Norwegian population, respectively, were analyzed using a stochastic time series analysis to characterize trends.

RESULTS

In Oslo County, the proportion of methicillin-resistant cases increased from 0.73% to 3.78% during the study period and was well modeled by an exponential growth with a doubling constant of 5.7 years (95% CI 4.5-7.4 years). In Health Region East, the proportion of MRSA cases increased from 0.4% to 2.1% from 2002 to 2008, with a best-fitting linear increase of 0.26% (95% CI 0.21-0.30%) per year. In both cases, the choice of a linear or exponential model for the time trend produced only marginally different model fits. We found no significant changes due to revised national MRSA guidelines published in June 2009. Significant variations in the increasing time trend were observed in the five hospitals within the region. The yearly reported incidence of MSSA was relatively stable in both study areas although we found seasonal patterns with peaks in August.

CONCLUSION

The level of MRSA is increasing in Norway, and the proportion of methicillin resistance in all S. aureus isolates are higher than the reported proportion of MRSA in invasive infections.

Antibiotic reduction campaigns do not necessarily decrease bacterial resistance: the example of methicillin-resistant Staphylococcus aureus

Interventions designed to reduce antibiotic consumption are under way worldwide. While overall reductions are often achieved, their impact on the selection of antibiotic-resistant selection cannot be assessed accurately from currently available data. We developed a mathematical model of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA) transmission inside and outside the hospital. A systematic simulation study was then conducted with two objectives: to assess the impact of antibiotic class-specific changes during an antibiotic reduction period and to investigate the interactions between antibiotic prescription changes in the hospital and the community. The model reproduced the overall reduction in MRSA frequency in French intensive-care units (ICUs) with antibiotic consumption in France from 2002 to 2003 as an input. However, the change in MRSA frequency depended on which antibiotic classes changed the most, with the same overall 10% reduction in antibiotic use over 1 year leading to anywhere between a 69% decrease and a 52% increase in MRSA frequency in ICUs and anywhere between a 37% decrease and a 46% increase in the community. Furthermore, some combinations of antibiotic prescription changes in the hospital and the community could act in a synergistic or antagonistic way with regard to overall MRSA selection. This study shows that class-specific changes in antibiotic use, rather than overall reductions, need to be considered in order to properly anticipate the impact of an antibiotic reduction campaign. It also highlights the fact that optimal gains will be obtained by coordinating interventions in hospitals and in the community, since the effect of an intervention in a given setting may be strongly affected by exogenous factors.

Impact of an enhanced antibiotic stewardship on reducing methicillin-resistant Staphylococcus aureus in primary and secondary healthcare settings

The objective of this study was to evaluate the impact of restricting high-risk antibiotics on methicillin-resistant Staphylococcus aureus (MRSA) incidence rates in a hospital setting. A secondary objective was to assess the impact of reducing fluoroquinolone use in the primary-care setting on MRSA incidence in the community. This was an interventional, retrospective, ecological investigation in both hospital and community (January 2006 to June 2010). Segmented regression analysis of interrupted time-series was employed to evaluate the intervention. The restriction of high-risk antibiotics was associated with a significant change in hospital MRSA incidence trend (coefficient=-0·00561, P=0·0057). Analysis showed that the intervention relating to reducing fluoroquinolone use in the community was associated with a significant trend change in MRSA incidence in community (coefficient=-0·00004, P=0·0299). The reduction in high-risk antibiotic use and fluoroquinolone use contributed to both a reduction in incidence rates of MRSA in hospital and community (primary-care) settings.

Interventions to improve antibiotic prescribing practices for hospital inpatients

BACKGROUND

The first publication of this review in Issue 3, 2005 included studies up to November 2003. This update adds studies to December 2006 and focuses on application of a new method for meta-analysis of interrupted time series studies and application of new Cochrane Effective Practice and Organisation of Care (EPOC) Risk of Bias criteria to all studies in the review, including those studies in the previously published version. The aim of the review is to evaluate the impact of interventions from the perspective of antibiotic stewardship. The two objectives of antibiotic stewardship are first to ensure effective treatment for patients with bacterial infection and second support professionals and patients to reduce unnecessary use and minimize collateral damage.

OBJECTIVES

To estimate the effectiveness of professional interventions that, alone or in combination, are effective in antibiotic stewardship for hospital inpatients, to evaluate the impact of these interventions on reducing the incidence of antimicrobial-resistant pathogens or Clostridium difficile infection and their impact on clinical outcome.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE from 1980 to December 2006 and the EPOC specialized register in July 2007 and February 2009 and bibliographies of retrieved articles. The main comparison is between interventions that had a restrictive element and those that were purely persuasive. Restrictive interventions were implemented through restriction of the freedom of prescribers to select some antibiotics. Persuasive interventions used one or more of the following methods for changing professional behaviour: dissemination of educational resources, reminders, audit and feedback, or educational outreach. Restrictive interventions could contain persuasive elements.

SELECTION CRITERIA

We included randomized clinical trials (RCTs), controlled clinical trials (CCT), controlled before-after (CBA) and interrupted time series studies (ITS). Interventions included any professional or structural interventions as defined by EPOC. The intervention had to include a component that aimed to improve antibiotic prescribing to hospital inpatients, either by increasing effective treatment or by reducing unnecessary treatment. The results had to include interpretable data about the effect of the intervention on antibiotic prescribing or microbial outcomes or relevant clinical outcomes.

DATA COLLECTION AND ANALYSIS

Two authors extracted data and assessed quality. We performed meta-regression of ITS studies to compare the results of persuasive and restrictive interventions. Persuasive interventions advised physicians about how to prescribe or gave them feedback about how they prescribed. Restrictive interventions put a limit on how they prescribed; for example, physicians had to have approval from an infection specialist in order to prescribe an antibiotic. We standardized the results of some ITS studies so that they are on the same scale (percent change in outcome), thereby facilitating comparisons of different interventions. To do this, we used the change in level and change in slope to estimate the effect size with increasing time after the intervention (one month, six months, one year, etc) as the percent change in level at each time point. We did not extrapolate beyond the end of data collection after the intervention. The meta-regression was performed using standard weighted linear regression with the standard errors of the coefficients adjusted where necessary.

MAIN RESULTS

For this update we included 89 studies that reported 95 interventions. Of the 89 studies, 56 were ITSs (of which 4 were controlled ITSs), 25 were RCT (of which 5 were cluster-RCTs), 5 were CBAs and 3 were CCTs (of which 1 was a cluster-CCT).Most (80/95, 84%) of the interventions targeted the antibiotic prescribed (choice of antibiotic, timing of first dose and route of administration). The remaining 15 interventions aimed to change exposure of patients to antibiotics by targeting the decision to treat or the duration of treatment. Reliable data about impact on antibiotic prescribing data were available for 76 interventions (44 persuasive, 24 restrictive and 8 structural). For the persuasive interventions, the median change in antibiotic prescribing was 42.3% for the ITSs, 31.6% for the controlled ITSs, 17.7% for the CBAs, 3.5% for the cluster-RCTs and 24.7% for the RCTs. The restrictive interventions had a median effect size of 34.7% for the ITSs, 17.1% for the CBAs and 40.5% for the RCTs. The structural interventions had a median effect of 13.3% for the RCTs and 23.6% for the cluster-RCTs. Data about impact on microbial outcomes were available for 21 interventions but only 6 of these also had reliable data about impact on antibiotic prescribing.Meta-analysis of 52 ITS studies was used to compare restrictive versus purely persuasive interventions. Restrictive interventions had significantly greater impact on prescribing outcomes at one month (32%, 95% confidence interval (CI) 2% to 61%, P = 0.03) and on microbial outcomes at 6 months (53%, 95% CI 31% to 75%, P = 0.001) but there were no significant differences at 12 or 24 months. Interventions intended to decrease excessive prescribing were associated with reduction in Clostridium difficile infections and colonization or infection with aminoglycoside- or cephalosporin-resistant gram-negative bacteria, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis. Meta-analysis of clinical outcomes showed that four interventions intended to increase effective prescribing for pneumonia were associated with significant reduction in mortality (risk ratio 0.89, 95% CI 0.82 to 0.97), whereas nine interventions intended to decrease excessive prescribing were not associated with significant increase in mortality (risk ratio 0.92, 95% CI 0.81 to 1.06).

AUTHORS' CONCLUSIONS

The results show that interventions to reduce excessive antibiotic prescribing to hospital inpatients can reduce antimicrobial resistance or hospital-acquired infections, and interventions to increase effective prescribing can improve clinical outcome. This update provides more evidence about unintended clinical consequences of interventions and about the effect of interventions to reduce exposure of patients to antibiotics. The meta-analysis supports the use of restrictive interventions when the need is urgent, but suggests that persuasive and restrictive interventions are equally effective after six months.

Impact of universal screening on MRSA bacteremias in a single acute NHS organisation (2006-12): interrupted time-series analysis

BACKGROUND

In November 2004, a national target was set for the English hospital trusts to reduce the Meticillin-Resistant Staphylococcus aureus (MRSA) bacteremia rate by 60% by April 2008 against the number during 2003/04 (baseline year). In our organisation the number of MRSA bacteremias had risen since 2002 and peaked at 75 in 2005/06. A target was set to reduce the number and series of specific and non- specific interventions was introduced including universal MRSA screening. This study analyzes the impact of universal MRSA screening using a quasi-experimental design using routinely gathered data.

METHODS

This study used data gathered routinely for clinical governance, quality control, financial management and outbreak monitoring purposes. Interrupted Time Series (ITS) analysis of 15 pre- and 19 post- universal MRSA screening (and decolonisation) quarterly numbers of bacteremias was carried out where Meticillin-Sensitive Staphylococcus aureus (MSSA) numbers served as non-equivalent dependent variable (control).

RESULTS

An immediate sharp fall in MRSA bacteremias was observed following the universal MRSA screening (and decolonisation) commenced in Q2, 2007. The number dropped sharply from 23 (Q2, 2007) to 10 (Q3, 2007) for all MRSA bacteremias, and, from 15 (Q2, 2007) to 6 (Q3, 2007) for bacteremias ≥48 hours of hospitalization. The declining trend continued reaching zero in Q2, 2009 and Q4, 2010 for those with ≥48 hours of hospitalization and all bacteremias, respectively. ITS analysis revealed significant impact of universal MRSA screening on all MRSA bacteremias (β2 -0.554, p 0.000) and those with ≥48 of hospitalization (β2 -0.577, p 0.001). Impact estimation predicted 17 and 13 bacteremias for all and those with ≥48 hours hospitalization, respectively in the 19th quarter post-intervention, if the intervention did not occur. The number of MRSA isolates from non-blood culture systemic sources as percentage of admissions also dropped significantly from 3.32% in Q2, 2007 to 1.51% in Q3, 2007 (β2 -0.506, p 0.000) which is still running low at 0.33% at the end of Q1, 2012. On the other hand, there was no statistically significant impact of universal screening on MSSA bacteremias.

CONCLUSIONS

We conclude that of all interventions, the universal MRSA screening (and decolonisation) is the most effective intervention associated with significant and sharp drop in MRSA burden.

A genomic portrait of the emergence, evolution, and global spread of a methicillin-resistant Staphylococcus aureus pandemic

The widespread use of antibiotics in association with high-density clinical care has driven the emergence of drug-resistant bacteria that are adapted to thrive in hospitalized patients. Of particular concern are globally disseminated methicillin-resistant Staphylococcus aureus (MRSA) clones that cause outbreaks and epidemics associated with health care. The most rapidly spreading and tenacious health-care-associated clone in Europe currently is EMRSA-15, which was first detected in the UK in the early 1990s and subsequently spread throughout Europe and beyond. Using phylogenomic methods to analyze the genome sequences for 193 S. aureus isolates, we were able to show that the current pandemic population of EMRSA-15 descends from a health-care-associated MRSA epidemic that spread throughout England in the 1980s, which had itself previously emerged from a primarily community-associated methicillin-sensitive population. The emergence of fluoroquinolone resistance in this EMRSA-15 subclone in the English Midlands during the mid-1980s appears to have played a key role in triggering pandemic spread, and occurred shortly after the first clinical trials of this drug. Genome-based coalescence analysis estimated that the population of this subclone over the last 20 yr has grown four times faster than its progenitor. Using comparative genomic analysis we identified the molecular genetic basis of 99.8% of the antimicrobial resistance phenotypes of the isolates, highlighting the potential of pathogen genome sequencing as a diagnostic tool. We document the genetic changes associated with adaptation to the hospital environment and with increasing drug resistance over time, and how MRSA evolution likely has been influenced by country-specific drug use regimens.

Review of indicators for cross-sectoral optimization of nosocomial infection prophylaxis - a perspective from structurally- and process-oriented hygiene

In the care of patients, the prevention of nosocomial infections is crucial. For it to be successful, cross-sectoral, interface-oriented hygiene quality management is necessary. The goal is to apply the HACCP (Hazard Assessment and Critical Control Points) concept to hospital hygiene, in order to create a multi-dimensional hygiene control system based on hygiene indicators that will overcome the limitations of a procedurally non-integrated and non-cross-sectoral view of hygiene.

Three critical risk dimensions can be identified for the implementation of three-dimensional quality control of hygiene in clinical routine: the constitution of the person concerned, the surrounding physical structures and technical equipment, and the medical procedures. In these dimensions, the establishment of indicators and threshold values enables a comprehensive assessment of hygiene quality. Thus, the cross-sectoral evaluation of the quality of structure, processes and results is decisive for the success of integrated infection prophylaxis.

This study lays the foundation for hygiene indicator requirements and develops initial concepts for evaluating quality management in hygiene.

Resistance surveillance studies: a multifaceted problem--the fluoroquinolone example

INTRODUCTION

This review summarizes data on the fluoroquinolone resistance epidemiology published in the previous 5 years.

MATERIALS AND METHODS

The data reviewed are stratified according to the different prescription patterns by either primary- or tertiary-care givers and by indication. Global surveillance studies demonstrate that fluoroquinolone- resistance rates increased in the past several years in almost all bacterial species except Staphylococcus pneumoniae and Haemophilus influenzae causing community-acquired respiratory tract infections (CARTIs), as well as Enterobacteriaceae causing community-acquired urinary tract infections. Geographically and quantitatively varying fluoroquinolone resistance rates were recorded among Gram-positive and Gram-negative pathogens causing healthcare-associated respiratory tract infections. One- to two-thirds of Enterobacteriaceae producing extended-spectrum β-lactamases (ESBLs) were fluoroquinolone resistant too, thus, limiting the fluoroquinolone use in the treatment of community- as well as healthcare-acquired urinary tract and intra-abdominal infections. The remaining ESBL-producing or plasmid-mediated quinolone resistance mechanisms harboring Enterobacteriaceae were low-level quinolone resistant. Furthermore, 10-30 % of H. influenzae and S. pneumoniae causing CARTIs harbored first-step quinolone resistance determining region (QRDR) mutations. These mutants pass susceptibility testing unnoticed and are primed to acquire high-level fluoroquinolone resistance rapidly, thus, putting the patient at risk. The continued increase in fluoroquinolone resistance affects patient management and necessitates changes in some current guidelines for the treatment of intra-abdominal infections or even precludes the use of fluoroquinolones in certain indications like gonorrhea and pelvic inflammatory diseases in those geographic areas in which fluoroquinolone resistance rates and/or ESBL production is high. Fluoroquinolone resistance has been selected among the commensal flora colonizing the gut, nose, oropharynx, and skin, so that horizontal gene transfer between the commensal flora and the offending pathogen as well as inter- and intraspecies recombinations contribute to the emergence and spread of fluoroquinolone resistance among pathogenic streptococci. Although interspecies recombinations are not yet the major cause for the emergence of fluoroquinolone resistance, its existence indicates that a large reservoir of fluoroquinolone resistance exists. Thus, a scenario resembling that of a worldwide spread of β-lactam resistance in pneumococci is conceivable. However, many resistance surveillance studies suffer from inaccuracies like the sampling of a selected patient population, restricted geographical sampling, and undefined requirements of the user, so that the results are biased. The number of national centers is most often limited with one to two participating laboratories, so that such studies are point prevalence but not surveillance studies. Selected samples are analyzed predominantly as either hospitalized patients or patients at risk or those in whom therapy failed are sampled; however, fluoroquinolones are most frequently prescribed by the general practitioner. Selected sampling results in a significant over-estimation of fluoroquinolone resistance in outpatients. Furthermore, the requirements of the users are often not met; the prescribing physician, the microbiologist, the infection control specialist, public health and regulatory authorities, and the pharmaceutical industry have diverse interests, which, however, are not addressed by different designs of a surveillance study. Tools should be developed to provide customer-specific datasets.

CONCLUSION

Consequently, most surveillance studies suffer from well recognized but uncorrected biases or inaccuracies. Nevertheless, they provide important information that allows the identification of trends in pathogen incidence and antimicrobial resistance.

Reduction of fluoroquinolone use is associated with a decrease in methicillin-resistant Staphylococcus aureus and fluoroquinolone-resistant Pseudomonas aeruginosa isolation rates: a 10 year study

OBJECTIVES

High rates of methicillin-resistant Staphylococcus aureus (MRSA) and fluoroquinolone-resistant Pseudomonas aeruginosa may be related, in part, to the overuse of fluoroquinolones. The objective was to analyse and correlate long-term surveillance data on MRSA and fluoroquinolone-resistant P. aeruginosa rates and antibiotic consumption after implementation of an institution-wide programme to reduce fluoroquinolone use.

METHODS

An interrupted time series/quasi-experimental study of monthly fluoroquinolone use and MRSA and fluoroquinolone-resistant P. aeruginosa isolation rates was carried out in a tertiary hospital during three periods: pre-intervention (January 2000-August 2005), intervention (September 2005-March 2006), and post-intervention (March 2006-March 2010). The effect of the intervention on the consumption of fluoroquinolones and bacterial resistance was assessed using segmented regression analyses.

RESULTS

Mean monthly fluoroquinolone consumption dropped by 29.1 defined daily doses per 1000 patient-days (DDD/1000 PD) (95% CI 13.1-45.9; P = 0.0005) from a mean of 148.2 to 119.1 DDD/1000 PD during the intervention period. A sustained and significant decrease in fluoroquinolone consumption of -0.95 DDD/1000 PD/month was also observed during the post-intervention period (P = 0.0002). During the post-intervention period the rate of fluoroquinolone-resistant P. aeruginosa continuously decreased, from a mean of 42% to 26%, with a constant relative change rate of -13%/year (95% CI -19 to -5, P = 0.001). A decrease in the MRSA rate was observed during the intervention period, from a mean resistance rate of 27% to 21% (P < 0.0001).

CONCLUSIONS

We showed the sustained impact of a fluoroquinolone control programme on the reduction of fluoroquinolone use with a significant decrease in fluoroquinolone-resistant P. aeruginosa and MRSA rates over 4 years.