The effect of antibiotic rotation on colonization with antibiotic-resistant bacilli in a neonatal intensive care unit

Systematic review of the effects of antimicrobial cycling on bacterial resistance rates within hospital settings

AIMS

Antimicrobial resistance is an evolving phenomenon with alarming public health consequences. Antibiotic cycling is a widely known antimicrobial stewardship initiative that encompasses periodical shifts in empirical treatment protocols with the aim of limiting selective pressures on bacterial populations. We present a review of the evidence regarding the actual impact of antimicrobial cycling on bacterial resistance control within hospitals.

METHODS

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

RESULTS

A systematic search process retrieved a sole randomised study, and so we broadened inclusion criteria to encompass quasi-experimental designs. Fifteen studies formed our dataset including seven prospective trials and eight before-and-after studies. Nine studies evaluated cycling vs. a control group and produced conflicting results whilst three studies compared cycling with antibiotic mixing, with none of the strategies appearing superior. The rest evaluated resistance dynamics of each of the on-cycle antibiotics with contradictory findings. Research protocols differed in parameters such as the cycle length, the choice of antibiotics, the opportunity to de-escalate to narrow-spectrum agents and the measurement of indicators of collateral damage. This limited our ability to evaluate the replicability of findings and the overall policy effects.

CONCLUSION

Dearth of robust designs and standardised protocols limits our ability to reach safe conclusions. Nonetheless, in view of the available data we find no reason to believe that cycling should be expected to improve antibiotic resistance rates within hospitals.

The Effect of Antibiotic-Cycling Strategy on Antibiotic-Resistant Bacterial Infections or Colonization in Intensive Care Units: A Systematic Review and Meta-Analysis

Background

Antibiotic‐resistant bacteria, especially multidrug‐resistant strains, play a key role in impeding critical patients from survival and recovery. The effectiveness of the empiric use of antibiotics in the circling manner in intensive care units (ICUs) has not been analyzed in detail and remains controversial. Therefore, this systematic review and meta‐analysis were conducted to evaluate antibiotic‐cycling effect on the incidence of antibiotic‐resistant bacteria.

Methods

We searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science for studies focusing on whether a cycling strategy of empiric use of antibiotics could curb the prevalence of antibiotic‐resistant bacteria in ICUs. The major outcomes were risk ratios (RRs) of antibiotic‐resistant infections or colonization per 1,000 patient days before and after the implementation of antibiotic cycling. A random‐effects model was adopted to estimate results in consideration of clinical heterogeneity among studies. The registration number of the meta‐analysis is CRD42018094464.

Results

Twelve studies, involving 2,261 episodes of resistant infections or colonization and 160,129 patient days, were included in the final analysis. Based on the available evidence, the antibiotic‐cycling strategy did not reduce the overall incidence of infections or colonization with resistant bacteria (RR = 0.823, 95% CI 0.655–1.035, p = .095). In subgroup analyses, the cycling strategy cut down the incidence of resistant bacteria more significantly than baseline period (p = .028) but showed no difference in comparison with mixing strategy (p = .758).

Linking Evidence to Action

Although the cycling strategy performed better than relatively free usage of antibiotics in the baseline period on reducing resistant bacteria, the cycling strategy did not show advantage when compared with the mixing strategy in subgroup analyses. In addition, these viewpoints still need more evidence to confirm.

Policy Statement: Antibiotic Stewardship in Pediatrics

Antibiotic overuse contributes to antibiotic resistance, which is a threat to public health. Antibiotic stewardship is a practice dedicated to prescribing antibiotics only when necessary and, when antibiotics are considered necessary, promoting the use of the appropriate agent(s), dose, duration, and route of therapy to optimize clinical outcomes while minimizing the unintended consequences of antibiotic use. Because there are differences in common infectious conditions, drug-specific considerations, and the evidence surrounding treatment recommendations (eg, first-line therapy and duration of therapy) between children and adults, this statement provides specific guidance for the pediatric population. This policy statement discusses the rationale for inpatient and outpatient antibiotic stewardship programs (ASPs); essential personnel, infrastructure, and activities required; approaches to evaluating their effectiveness; and gaps in knowledge that require further investigation. Key guidance for both inpatient and outpatient ASPs are provided.

Antibiotic Stewardship in Pediatrics

Antibiotic overuse contributes to antibiotic resistance, which is a threat to public health. Antibiotic stewardship is a practice dedicated to prescribing antibiotics only when necessary and, when antibiotics are considered necessary, promoting use of the appropriate agent(s), dose, duration, and route of therapy to optimize clinical outcomes while minimizing the unintended consequences of antibiotic use. Because there are differences in common infectious conditions, drug-specific considerations, and the evidence surrounding treatment recommendations (eg, first-line therapy, duration of therapy) between children and adults, this statement provides specific guidance for the pediatric population. This policy statement discusses the rationale for inpatient and outpatient antibiotic stewardship programs; essential personnel, infrastructure, and activities required; approaches to evaluating their effectiveness; and gaps in knowledge that require further investigation. Key guidance for both inpatient and outpatient antibiotic stewardship programs are provided.

Improving the Quality of Hospital Antibiotic Use: Impact on Multidrug-Resistant Bacterial Infections in Children

Antimicrobial resistance (AMR) is considered a rapidly growing global public health emergency. Neonates and children are among patients for whom antibiotics are largely prescribed and for whom the risk of AMR development is high. The phenomenon of increasing AMR has led to the need to develop measures aimed at the rational and effective use of the available drugs also in children and antimicrobial stewardship (AS), which is one of the measures that in adults has showed the highest efficacy in reducing antibiotic abuse and misuse, appears as an attractive approach. The aim of this manuscript is to analyze the basic principles and strategies of pediatric AS. To this end, we searched in PubMed articles published in years 2000 to 2019 containing "antimicrobial resistance," "antibiotic use," "antimicrobial stewardship," and "children" or "pediatric" as keywords. Our review showed that the balance between multi-resistant organisms and new antimicrobials is extremely precarious. The AS tools are the most important weapon at our disposal to stem the phenomenon. Careful monitoring of prescriptions, continuous training of prescribing physicians and collaboration with highly qualified multidisciplinary staff, creation of local and national guidelines, use of rapid diagnostic tests, technological means of support, and research activities by testing new broad-spectrum antibiotics are mandatory. However, all of these measures must be supported by adequate investment by national and international health organizations. Only by making AS daily practice, through the use of financial resources and dedicated staff, we can fight AMR to ensure safe and effective care for our young patients.

Longitudinal comparative trial of antibiotic cycling and mixing on emergence of gram negative bacterial resistance in a pediatric medical intensive care unit

PURPOSE

To compare antibiotic mixing vs. cycling with respect to acquisition of resistance and PICU mortality.

MATERIALS AND METHODS

Children between >1 month to 12 years admitted to a medical PICU were enrolled over three phases (baseline, mixing and cycling) with washout interval of 3 months following each antibiotic strategy. Following a baseline phase, empiric gram negative antibiotic protocol for suspected HCAI, was sequentially subjected to mixing and cycling using Latin Square methodology. Surveillance cultures were taken at admission, 48 h, weekly thereafter and within 2 days of PICU discharge. Acquisition of resistance and PICU mortality were primary and secondary outcomes respectively.

RESULTS

778 children were enrolled; 99 baseline, 146 mixing, 362 cycling, and 171 during two washout phases. Proportion of children with acquired resistance at baseline (56.6%) was significantly higher than mixing (22.6%) and cycling (18.51%) (p < .0001). Adjusted hazards of acquired resistance (HR:0.82; 95% CI: 0.53-1.25, p = .352), and PICU mortality (RR1.07; 95% CI: 0.71-1.60, p = .72) were similar in cycling and mixing strategies.

CONCLUSIONS

Acquisition of resistance was significantly lower in both mixing and cycling as compared to baseline phase. Both were similar with respect to risk of antibiotic resistance as well as incidence of HCAI and PICU mortality.

Effects of Antibiotic Cycling Policy on Incidence of Healthcare-Associated MRSA and Clostridioides difficile Infection in Secondary Healthcare Settings

This quasi-experimental study investigated the effect of an antibiotic cycling policy based on time-series analysis of epidemiologic data, which identified antimicrobial drugs and time periods for restriction. Cyclical restrictions of amoxicillin/clavulanic acid, piperacillin/tazobactam, and clarithromycin were undertaken over a 2-year period in the intervention hospital. We used segmented regression analysis to compare the effect on the incidence of healthcare-associated Clostridioides difficile infection (HA-CDI), healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA), and new extended-spectrum β-lactamase (ESBL) isolates and on changes in resistance patterns of the HA-MRSA and ESBL organisms between the intervention and control hospitals. HA-CDI incidence did not change. HA-MRSA incidence increased significantly in the intervention hospital. The resistance of new ESBL isolates to amoxicillin/clavulanic acid and piperacillin/tazobactam decreased significantly in the intervention hospital; however, resistance to piperacillin/tazobactam increased after a return to the standard policy. The results question the value of antibiotic cycling to antibiotic stewardship.

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

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

Evolutionary epidemiology models to predict the dynamics of antibiotic resistance

The evolution of resistance to antibiotics is a major public health problem and an example of rapid adaptation under natural selection by antibiotics. The dynamics of antibiotic resistance within and between hosts can be understood in the light of mathematical models that describe the epidemiology and evolution of the bacterial population. "Between-host" models describe the spread of resistance in the host community, and in more specific settings such as hospitalized hosts (treated by antibiotics at a high rate), or farm animals. These models make predictions on the best strategies to limit the spread of resistance, such as reducing transmission or adapting the prescription of several antibiotics. Models can be fitted to epidemiological data in the context of intensive care units or hospitals to predict the impact of interventions on resistance. It has proven harder to explain the dynamics of resistance in the community at large, in particular because models often do not reproduce the observed coexistence of drug-sensitive and drug-resistant strains. "Within-host" models describe the evolution of resistance within the treated host. They show that the risk of resistance emergence is maximal at an intermediate antibiotic dose, and some models successfully explain experimental data. New models that include the complex host population structure, the interaction between resistance-determining loci and other loci, or integrating the within- and between-host levels will allow better interpretation of epidemiological and genomic data from common pathogens and better prediction of the evolution of resistance.

Antibiotic Cycling and Antibiotic Mixing: Which One Best Mitigates Antibiotic Resistance?

Can we exploit our burgeoning understanding of molecular evolution to slow the progress of drug resistance? One role of an infection clinician is exactly that: to foresee trajectories to resistance during antibiotic treatment and to hinder that evolutionary course. But can this be done at a hospital-wide scale? Clinicians and theoreticians tried to when they proposed two conflicting behavioral strategies that are expected to curb resistance evolution in the clinic, these are known as “antibiotic cycling” and “antibiotic mixing.” However, the accumulated data from clinical trials, now approaching 4 million patient days of treatment, is too variable for cycling or mixing to be deemed successful. The former implements the restriction and prioritization of different antibiotics at different times in hospitals in a manner said to “cycle” between them. In antibiotic mixing, appropriate antibiotics are allocated to patients but randomly. Mixing results in no correlation, in time or across patients, in the drugs used for treatment which is why theorists saw this as an optimal behavioral strategy. So while cycling and mixing were proposed as ways of controlling evolution, we show there is good reason why clinical datasets cannot choose between them: by re-examining the theoretical literature we show prior support for the theoretical optimality of mixing was misplaced. Our analysis is consistent with a pattern emerging in data: neither cycling or mixing is a priori better than the other at mitigating selection for antibiotic resistance in the clinic.

Key words: antibiotic cycling, antibiotic mixing, optimal control, stochastic models.

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.

Randomized Control Trial of Human Recombinant Lactoferrin: A Substudy Reveals Effects on the Fecal Microbiome of Very Low Birth Weight Infants

The purpose of this study is to evaluate the effects of enteral lactoferrin on the fecal microbiome and contrast those influences with the neonatal intensive care unit (NICU) environment. We theorized that lactoferrin and the NICU habitat shape the fecal microbial composition of very preterm infants. Although functions attributed to lactoferrin include intestinal immune system development and emergence of a healthy gut microbiota, evidence is limited. Twenty-one very low birth weight (VLBW <1500 g) infants received twice-daily talactoferrin (TLf, a drug designation for recombinant human lactoferrin) or its excipient by gastric gavage from day 1-28 of life. Twenty-four-hour fecal samples were collected on day 21 of life and compared with fecal operational taxonomy units (OTUs) in treated and control infants in 2 NICUs. Workflow included fecal DNA isolation, generation of amplicons for the V1-V3 region of bacterial 16S ribosomal RNA, and sequencing of a gel-purified multiplex amplicon library using a Roche 454 GS FLX Titanium (Roche, Branford, Connecticut) platform and protocols. Fecal OTUs per infant were higher in NICU 1 vs NICU 2 (P < .001), consistent with fewer antibiotic days (P < .02) and a shorter duration of parenteral nutrition (P < .007) in NICU 1. Proteobacteria and Firmicutes were the major phyla in infants treated with TLf and placebo. Among Enterobacteriaceae, TLf prophylaxis reduced Enterobacter and Klebsiella, but increased Citrobacter in feces of VLBW infants. Citrobacter caused no neonatal infections in the study population. OTUs for Clostridiaceae increased in NICU 1 among infants treated with TLf. Importantly, OTUs of staphylococci were barely detectable in both NICUs among infants fed TLf. Fewer hospital-acquired infections occurred in infants treated with TLf vs controls, although the reduction was seen mostly in coagulase-negative staphylococci-related bloodstream and central line infections (P = .06). TLf modified the fecal microbiome in VLBW infants, but care practices in the NICU habitat also contributed. Future research must establish whether elimination vs enrichment of gut-related microbiota reduces clinically significant hospital-acquired infections and promotes a healthy commensal microflora in the intestines of VLBW infants.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00854633.

Evaluation of a Mixing versus a Cycling Strategy of Antibiotic Use in Critically-Ill Medical Patients: Impact on Acquisition of Resistant Microorganisms and Clinical Outcomes

Objective

To compare the effect of two strategies of antibiotic use (mixing vs. cycling) on the acquisition of resistant microorganisms, infections and other clinical outcomes.

Methods

Prospective cohort study in an 8-bed intensive care unit during 35- months in which a mixing-cycling policy of antipseudomonal beta-lactams (meropenem, ceftazidime/piperacillin-tazobactam) and fluoroquinolones was operative. Nasopharyngeal and rectal swabs and respiratory secretions were obtained within 48h of admission and thrice weekly thereafter. Target microorganisms included methicillin-resistant S. aureus, vancomycin-resistant enterococci, third-generation cephalosporin-resistant Enterobacteriaceae and non-fermenters.

Results

A total of 409 (42%) patients were included in mixing and 560 (58%) in cycling. Exposure to ceftazidime/piperacillin-tazobactam and fluoroquinolones was significantly higher in mixing while exposure to meropenem was higher in cycling, although overall use of antipseudomonals was not significantly different (37.5/100 patient-days vs. 38.1/100 patient-days). There was a barely higher acquisition rate of microorganisms during mixing, but this difference lost its significance when the cases due to an exogenous Burkholderia cepacia outbreak were excluded (19.3% vs. 15.4%, OR 0.8, CI 0.5–1.1). Acquisition of Pseudomonas aeruginosa resistant to the intervention antibiotics or with multiple-drug resistance was similar. There were no significant differences between mixing and cycling in the proportion of patients acquiring any infection (16.6% vs. 14.5%, OR 0.9, CI 0.6–1.2), any infection due to target microorganisms (5.9% vs. 5.2%, OR 0.9, CI 0.5–1.5), length of stay (median 5 d for both groups) or mortality (13.9 vs. 14.3%, OR 1.03, CI 0.7–1.3).

Conclusions

A cycling strategy of antibiotic use with a 6-week cycle duration is similar to mixing in terms of acquisition of resistant microorganisms, infections, length of stay and mortality.

Inpatient Antimicrobial Stewardship in Pediatrics: A Systematic Review

BACKGROUND

The clinical and economic outcomes associated with pediatric antimicrobial stewardship programs (ASPs) and other supplemental antimicrobial stewardship (AS) interventions have not been well described or reviewed.

METHODS

We performed a systematic review using PubMed to identify studies with any of the following terms in the title or abstract: "antimicrobial stewardship," "antimicrobial control," "antibiotic control," or "antibiotic stewardship." Studies were further limited to inpatient studies in the United States that contained the terms: "child," "children," "pediatric*" ("*" includes all terms with the same stem), "paediatric,*" "newborn," "infant," or "neonat,*" in the title or abstract. Clinical and economic outcomes from each relevant study were summarized.

RESULTS

Nine original studies reported outcomes related to formal pediatric ASPs. An additional 8 studies focused on specific AS interventions; 3 on management of community-acquired pneumonia, 2 on vancomycin-specific initiatives, and 1 each on clinical support, antibiotic restriction, and antibiotic rotation. Reported outcomes include decreases in antimicrobial utilization (11 studies), prescribing errors (3 studies), and drug costs (3 studies). Five studies assessed the potential adverse effects of AS interventions on patient safety and found none. Data to support an association between pediatric AS interventions and antimicrobial resistance are limited.

CONCLUSIONS

A small number of pediatric studies evaluating ASPs or other AS strategies have been published. These studies demonstrate reductions in antimicrobial utilization, cost, and prescribing errors with no apparent negative impact on patient safety. Although the studies are promising, the current evidence base is limited. Additional studies focusing on the appropriateness and outcomes of antimicrobial prescribing practices as well as more formalized economic evaluations are needed.

Optimizing research methods used for the evaluation of antimicrobial stewardship programs

Antimicrobial stewardship programs (ASPs) are an increasingly common intervention for optimizing antimicrobial therapy in healthcare settings. These programs aim to improve patient care and limit the emergence and spread of multidrug-resistant organisms by supporting prudent antimicrobial use. However, pressure from the current reimbursement climate necessitates that ASPs operate as cost-cutting programs rather than focus on patient outcomes. This has forced the research that is evaluating ASP interventions to concentrate heavily on economic outcomes. As the science of antimicrobial stewardship advances, it is essential that well-conducted evaluations, focused on patient and microbial outcomes, serve as the evidence base that directs optimal ASP intervention design and implementation. In this review, we provide guidance and recommendations for the design of studies to evaluate the impact of ASP interventions on patient and microbial outcomes.

Antibiotic rotation strategies to reduce antimicrobial resistance in Gram-negative bacteria in European intensive care units: study protocol for a cluster-randomized crossover controlled trial

Background

Intensive care units (ICU) are epicenters for the emergence of antibiotic-resistant Gram-negative bacteria (ARGNB) because of high rates of antibiotic usage, rapid patient turnover, immunological susceptibility of acutely ill patients, and frequent contact between healthcare workers and patients, facilitating cross-transmission.

Antibiotic stewardship programs are considered important to reduce antibiotic resistance, but the effectiveness of strategies such as, for instance, antibiotic rotation, have not been determined rigorously. Interpretation of available studies on antibiotic rotation is hampered by heterogeneity in implemented strategies and suboptimal study designs. In this cluster-randomized, crossover trial the effects of two antibiotic rotation strategies, antibiotic mixing and cycling, on the prevalence of ARGNB in ICUs are determined. Antibiotic mixing aims to create maximum antibiotic heterogeneity, and cycling aims to create maximum antibiotic homogeneity during consecutive periods.

Methods/Design

This is an open cluster-randomized crossover study of mixing and cycling of antibiotics in eight ICUs in five European countries. During cycling (9 months) third- or fourth-generation cephalosporins, piperacillin-tazobactam and carbapenems will be rotated during consecutive 6-week periods as the primary empiric treatment in patients suspected of infection caused by Gram-negative bacteria. During mixing (9 months), the same antibiotics will be rotated for each consecutive antibiotic course. Both intervention periods will be preceded by a baseline period of 4 months. ICUs will be randomized to consecutively implement either the mixing and then cycling strategy, or vice versa. The primary outcome is the ICU prevalence of ARGNB, determined through monthly point-prevalence screening of oropharynx and perineum. Secondary outcomes are rates of acquisition of ARGNB, bacteremia and appropriateness of therapy, length of stay in the ICU and ICU mortality. Results will be adjusted for intracluster correlation, and patient- and ICU-level variables of case-mix and infection-prevention measures using advanced regression modeling.

Discussion

This trial will determine the effects of antibiotic mixing and cycling on the unit-wide prevalence of ARGNB in ICUs.

Trial registration

ClinicalTrials.gov NCT01293071 December 2010.

Cycling empirical antibiotic therapy in hospitals: meta-analysis and models

The rise of resistance together with the shortage of new broad-spectrum antibiotics underlines the urgency of optimizing the use of available drugs to minimize disease burden. Theoretical studies suggest that coordinating empirical usage of antibiotics in a hospital ward can contain the spread of resistance. However, theoretical and clinical studies came to different conclusions regarding the usefulness of rotating first-line therapy (cycling). Here, we performed a quantitative pathogen-specific meta-analysis of clinical studies comparing cycling to standard practice. We searched PubMed and Google Scholar and identified 46 clinical studies addressing the effect of cycling on nosocomial infections, of which 11 met our selection criteria. We employed a method for multivariate meta-analysis using incidence rates as endpoints and find that cycling reduced the incidence rate/1000 patient days of both total infections by 4.95 [9.43–0.48] and resistant infections by 7.2 [14.00–0.44]. This positive effect was observed in most pathogens despite a large variance between individual species. Our findings remain robust in uni- and multivariate metaregressions. We used theoretical models that reflect various infections and hospital settings to compare cycling to random assignment to different drugs (mixing). We make the realistic assumption that therapy is changed when first line treatment is ineffective, which we call “adjustable cycling/mixing”. In concordance with earlier theoretical studies, we find that in strict regimens, cycling is detrimental. However, in adjustable regimens single resistance is suppressed and cycling is successful in most settings. Both a meta-regression and our theoretical model indicate that “adjustable cycling” is especially useful to suppress emergence of multiple resistance. While our model predicts that cycling periods of one month perform well, we expect that too long cycling periods are detrimental. Our results suggest that “adjustable cycling” suppresses multiple resistance and warrants further investigations that allow comparing various diseases and hospital settings.

The rise of antibiotic resistance is a major concern for public health. In hospitals, frequent usage of antibiotics leads to high resistance levels; at the same time the patients are especially vulnerable. We therefore urgently need treatment strategies that limit resistance without compromising patient care. Here, we investigate two strategies that coordinate the usage of different antibiotics in a hospital ward: “cycling”, i.e. scheduled changes in antibiotic treatment for all patients, and “mixing”, i.e. random assignment of patients to antibiotics. Previously, theoretical and clinical studies came to different conclusions regarding the usefulness of these strategies. We combine meta-analyses of clinical studies and epidemiological modeling to address this question. Our meta-analyses suggest that cycling is beneficial in reducing the total incidence rate of hospital-acquired infections as well as the incidence rate of resistant infections, and that this is most pronounced at low baseline levels of resistance. We corroborate our findings with theoretical epidemiological models. When incorporating treatment adjustment upon deterioration of a patient's condition (“adjustable cycling”), we find that our theoretical model is in excellent accordance with the clinical data. With this combined approach we present substantial evidence that adjustable cycling can be beneficial for suppressing the emergence of multiple resistance.

Surgical site infections in infants admitted to the neonatal intensive care unit

BACKGROUND

Surgical interventions are common in infants admitted to the neonatal intensive care unit (NICU). Despite our awareness of the broad impact of surgical site infection (SSI), there are little data in neonates. Our objective was to determine the rate and clinical impact of SSI in infants admitted to the NICU.

METHODS

Provincial population-based study of infants admitted to a tertiary care NICU. SSI, explicitly defined, was included if it occurred within 30 days of a skin/mucosal-breaking surgical intervention.

RESULTS

Among 724 infants who underwent 1039 surgical interventions very low birth weight (VLBW) infants were over-represented. The overall SSI rate was 4.3 per 100 interventions [CI 95% 3.2 to 5.7], up to 19 per 100 dirty interventions (wound class 4) [CI 95% 4.0 to 46]. Rates were higher in infants following gastroschisis closure (13 per 100 infants [CI 95% 5.8 to 24]), whereas they were generally low following a ligation of a ductus arteriosus. Infants with SSI required longer hospitalization after adjusting for co-morbidities (p<0.001).

CONCLUSIONS

Data from this relatively large contemporary study suggest that SSI rates in the NICU setting are more comparable to the pediatric age group. However, VLBW infants and those undergoing gastroschisis closure represent high risk groups.

Risk factors and outcomes for multidrug-resistant Gram-negative bacteremia in the NICU

OBJECTIVES

To assess the risk factors antibiotic therapy and outcomes of multidrug-resistant (MDR) Gram-negative bacilli (GNB) bacteremia in NICU patients.

METHODS

Episodes of MDR GNB bacteremia were compared with a non-MDR GNB bacteremia group in an 8-year cohort study.

RESULTS

Of 1106 bacteremias, 393 (35.5%) were caused by GNB. Seventy (18.6%) were caused by an MDR strain. The most frequent mechanism of resistance was extended-spectrum β-lactamase production (67.1%), mainly by Klebsiella pneumoniae (59.6%). Previous antibiotic exposure to third-generation cephalosporin (odds ratio [OR]: 5.97; 95% confidence interval [CI]: 2.37-15.08; P < .001) and carbapenem (OR: 3.60; 95% CI: 1.26-10.29; P = .017) and underlying renal disease (OR: 7.08; 95% CI: 1.74-28.83; P = .006) were identified as independent risk factors for MDR GNB acquisition. Patients with MDR GNB bacteremia more likely received inadequate initial antibiotic therapy (72.9% vs 7.8%; P < .001) had higher rates of infectious complication (21.4% vs 10.5%; P = .011) and overall case fatality +rate (28.6% vs 10.5%; P < .001). Independent risk factors for overall mortality were presence of infectious complications after bacteremia (OR: 3.16; 95% CI: 1.41-7.08; P = .005) and underlying secondary pulmonary hypertension with or without cor pulmonale (OR: 6.19; 95% CI: 1.88-20.31; P = .003).

CONCLUSIONS

MDR GNB accounted for 18.6% of all neonatal GNB bacteremia in the NICU, especially in those with previous broad-spectrum antibiotic therapy and underlying renal disease. The most frequent mechanism of resistance was extended-spectrum β-lactamase (ESBL) production. Neonates with MDR GNB were more likely to develop infectious complications, which were independently associated with a higher overall case-fatality rate.

Antibiotic resistance in the intensive care unit setting

Antibiotic resistance is an important factor influencing clinical outcome for patients in intensive care units. It is also associated with increased healthcare costs resulting from prolonged patient stays. The problem of antibiotic resistance is particularly acute in intensive care units because they house seriously ill patients who are predisposed to infection, as a result of which, antibiotic use is extremely common. Strategies for controlling resistance in intensive care units have focused on attempting to reduce unnecessary antibiotic use, while at the same time ensuring adequate antibiotic cover is provided. The formulation of policies for the effective use of antibiotics in individual intensive care units requires a multidisciplinary approach, entailing regular epidemiological surveillance, together with input from critical care specialists, infectious disease specialists and pharmacists.

Neonatal and pediatric antimicrobial stewardship programs in Europe-defining the research agenda

The relationship between suboptimal use of antimicrobials and antimicrobial resistance has become increasingly clear. Despite significant international effort aimed at reducing inappropriate antimicrobial prescribing in hospitals, antimicrobial resistance remains a major public health threat. Antimicrobial Stewardship Programs (ASPs) comprise a series of measures aimed at optimizing the use of antimicrobials, while improving the quality of patient care and promoting cost-effectiveness. This discussion article aims to summarize some of the approaches that have been used in neonatal and pediatric ASPs, with a particular focus on the European healthcare setting. Current evidence demonstrates neonatal and pediatric ASPs to be safe, practical to implement, generally cost-effective and possibly associated with a reduction in antimicrobial resistance rates. This review identified that, despite the recognized need for additional evidence and information on implementation, published data on pediatric ASPs derives mainly from the United States, with very few published reports on formal ASPs in European children's hospitals. Consequently, the optimal method of implementation remains unknown within a European setting. Future research needs to include novel study designs on how best to introduce ASPs, monitoring of clinically relevant outcomes and cost-effectiveness with improved measurement of the impact on antimicrobial resistance.

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.

Continuous surveillance to reduce extended-spectrum β-lactamase Klebsiella pneumoniae colonization in the neonatal intensive care unit

BACKGROUND

Clinical illness caused by resistant bacteria usually represents a wider problem of asymptomatic colonization. Active surveillance with appropriate institution of isolation precautions represents a potential mechanism to control colonization and reduce infection. The neonatal intensive care unit (NICU) is an environment particularly appropriate for such interventions. Neonates are rarely colonized by resistant bacteria on admission and staff enthusiasm for infection control is high.

OBJECTIVE

To reduce extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) acquisition amongst neonates through a continuous active surveillance intervention.

METHODS

Fecal ESBL-KP cultures were performed weekly on all neonates over 4 years. Neonates with positive cultures were managed with contact precautions by dedicated nurses separately from other neonates. ESBL-KP acquisition amongst neonates staying >7 days was compared for the consecutive years. A subset of ESBL-KP isolates was typed with pulsed-field gel electrophoresis (PFGE).

RESULTS

Surveillance cultures were obtained from 1,482/1,763 (84%) neonates over 4 years. ESBL-KP acquisition decreased continuously from 94/397 (24%) neonates in 2006 to 33/304 (11%) in 2009 (p < 0.001, hazard ratio 0.75, 95% confidence interval 0.66-0.85, p < 0.001 for comparison of years). Hospital-wide ESBL-KP acquisition did not decrease outside the NICU. PFGE identified identical ESBL-KP strains from multiple neonates on six occasions and different strains from single neonates on seven occasions.

CONCLUSIONS

ESBL-KP is probably both imported into and spread within the NICU. Continuous long-term surveillance with cohorting was associated with a decrease in ESBL-KP acquisition within the NICU. This low-risk intervention should be considered as a means to decrease neonatal acquisition of resistant bacteria.

Antibiotic resistance in neonatal intensive care unit pathogens: mechanisms, clinical impact, and prevention including antibiotic stewardship

Antimicrobial-resistant pathogens are of increasing concern in the neonatal intensive care unit population. A myriad of resistance mechanisms exist in microorganisms, and management can be complex because broad-spectrum antibiotics are increasingly needed. Control and prevention of antibiotic-resistant organisms (AROs) require an interdisciplinary team with continual surveillance. Judicious use of antibiotics; minimizing exposure to risk factors, when feasible; and effective hand hygiene are crucial interventions to reduce infection and transmission of AROs.

Implementation of antibiotic rotation protocol improves antibiotic susceptibility profile in a surgical intensive care unit

BACKGROUND

Antibiotic rotation has been proposed as a way to potentially reduce the development of antimicrobial resistant bacteria in intensive care units. We assessed the effect of an antibiotic rotation protocol on the antibiotic susceptibility profiles of three clinically relevant gram-negative microorganisms within our surgical intensive care unit (SICU).

METHODS

Our SICU implemented an antibiotic rotation protocol in 2003. Four antibiotics (piperacillin/tazobactam, imipenem/cilastin, ceftazidime, and ciprofloxacin) were rotated as the primary antibiotic used to treat suspected gram-negative infections every month, with the four-drug cycle being repeated every 4 months. Antibiotic susceptibility data for three microorganisms (Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae) were collected for the year before (2002) and the year after (2004) the implementation of the rotation protocol. Changes in antimicrobial susceptibility rates were analyzed for the three microorganisms. As a comparison, a similar analysis was conducted for microorganisms isolated from our medical intensive care unit, where no antibiotic rotation protocol was implemented.

RESULTS

Implementation of an antibiotic rotation protocol in our SICU resulted in a significant increase in the percentage of P. aeruginosa isolates sensitive to ceftazidime (67% in 2002 vs. 92% in 2004, p = 0.002) and piperacillin/tazobactam (78% in 2002 vs. 92% in 2004, p = 0.043). Isolates from the medical intensive care unit did not demonstrate an increase in antimicrobial susceptibility. In fact, the susceptibility of E. coli to piperacillin/tazobactam decreased during this time period (p = 0.047).

CONCLUSIONS

Implementation of an antibiotic rotation protocol in our SICU resulted in overall improvement in the antibiotic susceptibility profile of gram-negative microorganisms relative to our medical intensive care unit, where such a protocol was not used.

A review of antimicrobial control strategies in hospitalized and ambulatory pediatric populations

Antimicrobial resistance is a growing crisis in healthcare. Various antimicrobial stewardship strategies have been used to control antibiotic use in efforts to reduce antibiotic resistance. We conducted a systematic review of antimicrobial stewardship programs in pediatric settings. Twenty-eight published studies met inclusion criteria. The majority (21 of 28) of studies had positive outcomes, but only 6 measured the impact of interventions on antimicrobial resistance. Prescriber education for a specific diagnosis (eg, otitis media) was the most effective intervention in the outpatient setting. Ancillary laboratory tests (eg, rapid diagnostic assays for viral pathogens) were most effective in the inpatient setting. Most studies had moderate to high risk of bias, mainly because of selection bias, inadequate preintervention data for time series analysis, and contamination between treatment groups. To date, there are a limited number of studies assessing antimicrobial stewardship in pediatric settings and these have heterogeneous study designs. Thus, it is difficult to determine the most effective interventions. Future studies should be designed to overcome the biases encountered in current publications.

Surveillance of multidrug-resistant gram-negative bacilli in a neonatal intensive care unit: prominent role of cross transmission

BACKGROUND

Multidrug-resistant gram-negative bacilli (MDRGN) are an important cause of nosocomial infections in neonatal intensive care units (NICUs). We conducted a 1-year prospective surveillance study in an NICU to assess the epidemiology of MDRGN among newborns and the relative importance of acquisition routes.

METHODS

Neonates admitted at the NICU of the Dipartimento Materno-Infantile, University Hospital, Palermo, Italy, from January 7, 2003, to January 6, 2004, were included in the study. Colonization of patients with MDRGN was assessed by cultures of rectal swabs sampled twice a week. Pulsed-field gel electrophoresis was used to determine relatedness among MDRGN isolates. Extended-spectrum beta-lactamases (ESBL) and metallo-beta-lactamases (MBL) production was investigated. The association between risk factors at admission and during the NICU stay was analyzed by multivariate logistic regression analysis.

RESULTS

During the 12-month period January 7, 2003, through January 6, 2004, 1021 rectal swabs were cultured from 210 infants. One hundred sixteen infants (55.2%) were colonized by MDRGN. The monthly incidence of acquisition of MDRGN ranged between 12 and 53 cases per 1000 patient-days. Eighty-four (72.4%) of the 116 patients were cross colonized. Exclusive feeding by formula was significantly associated with cross transmission (RR=1.8, P=.02). Fifty-seven (49.1%) of the 116 infants were colonized by ESBL-producing Enterobacteriaceae. Feeding by formula was significantly associated with colonization by ESBL-producing Enterobacteriaceae (RR=1.6, P=.007), whereas breastfeeding proved to be protective (RR=0.5, P=.001). Ninety-two (43.8%) of the 210 infants received antibiotics during the NICU stay, but exposure to those most frequently administered, ampicillin-sulbactam and gentamicin, was not significantly associated with MDRGN colonization.

CONCLUSION

The emerging picture of this study is that spread of MDRGN in an NICU may be the result of diffuse cross transmission and, consequently, of poor infection control procedures.

Comparative effects of single-dose ceftriaxone versus three oral antibiotic regimens on stool colonization by resistant bacilli in children

OBJECTIVE

The use of short-term intramuscular ceftriaxone for pediatric ambulatory conditions raises concerns regarding the promotion of resistance among colonizing enteric bacteria. This study was designed to assess the prevalence of stool colonization with resistant Gram-negative bacilli after single-dose ceftriaxone treatment compared with other regimens for acute otitis media.

METHODS

Children age 3 months to 7 years and diagnosed with acute otitis media were randomized to receive treatment with single-dose ceftriaxone or with oral cefprozil, amoxicillin or azithromycin. Stool samples were obtained at enrollment and then 3-5 days, 10-14 days, and 28-30 days after therapy was initiated and screened for the presence of facultative Gram-negative bacilli resistant to ceftriaxone, cefprozil, amoxicillin, piperacillin, piperacillin-tazobactam and tobramycin. Mean prevalence of colonization by resistant organisms for each treatment group was compared at each time point.

RESULTS

One thousand nine subjects were enrolled. The prevalence of colonization by a Gram-negative bacillus resistant to at least 1 of the screening antibiotics decreased after receipt of ceftriaxone but returned close to values measured at study entry by 30 days. A qualitatively similar pattern was noted for the 3 other regimens, but a quantitatively greater decrease in the prevalence of colonization by a resistant bacterium was noted at the 3- to 5-day and 10- to 14-day visits among azithromycin recipients (P < 0.001). Colonization by a Gram-negative bacillus resistant specifically to ceftriaxone was unusual at each study visit, regardless of treatment assignment.

CONCLUSIONS

A single intramuscular dose of ceftriaxone had a similar effect on the prevalence of antibiotic-resistant Gram-negative facultative bacilli in the stool of healthy children when compared with commonly used oral agents.

Healthcare Epidemiology: Potential Confounding in Evaluating Infection‐Control Interventions in Hospital Settings: Changing Antibiotic Prescription

The colonization dynamics of antibiotic-resistant pathogens in hospital settings are complex, with multiple and continuously interacting variables (e.g., introduction of resistance, infection-control practices, antibiotic use). Quantification of these variables is indispensable in the evaluation of intervention studies, because these variables represent potential confounders. In this article, the complexity of colonization dynamics is described. Through a systematic review, we identified studies that evaluated the modification of antibiotic prescription to reduce antibiotic resistance in intensive care units (n=19), and the extent of confounding-control was determined. Most studies evaluated antimicrobial restriction/substitution (n=12) or antibiotic rotation (n=4). Sixteen studies had a prospective cohort design (before-after), of which 12 were without a control group. Introduction of antibiotic resistance was determined in 10 studies. The relative importance of colonization routes and adherence to infection-control measures were not determined in any study. Therefore, it remains uncertain whether observed changes in the prevalence of antibiotic resistance after intervention were causally related to the intervention. Appropriate choices of study design, primary end point (colonization rates rather than infection rates) and statistical tests, determination of colonization routes, and control of potential confounders are needed to increase validity of intervention studies.

Systematic review of antimicrobial drug prescribing in hospitals

Standardizing methods and reporting could improve interventions that reduce Clostridium difficile–associated diarrhea and antimicrobial drug resistance.

Prudent prescribing of antimicrobial drugs to hospital inpatients may reduce incidences of antimicrobial drug resistance and healthcare-associated infection. We reviewed the literature from January 1980 to November 2003 to identify rigorous evaluations of interventions to improve hospital prescribing of antimicrobial drugs. We identified 66 studies with interpretable data, of which 16 reported 20 microbiologic outcomes: gram-negative resistant bacteria, 10 studies; Clostridium difficile–associated diarrhea, 5 studies; vancomycin-resistant enterococci, 3 studies; and methicillin-resistant Staphylococcus aureus, 2 studies. Four studies provided strong evidence that the intervention changed microbial outcomes with low risk for alternative explanations, 8 studies provided less convincing evidence, and 4 studies provided no evidence. The strongest and most consistent evidence was for C. difficile–associated diahrrea, but we were able to analyze only the immediate impact of interventions because of nonstandardized durations of follow-up. The ability to compare results of studies could be substantially improved by standardizing methods and reporting.

Systematic Review of Antimicrobial Drug Prescribing in Hospitals

Prudent prescribing of antimicrobial drugs to hospital inpatients may reduce incidences of antimicrobial drug resistance and healthcare-associated infection. We reviewed the literature from January 1980 to November 2003 to identify rigorous evaluations of interventions to improve hospital prescribing of antimicrobial drugs. We identified 66 studies with interpretable data, of which 16 reported 20 microbiologic outcomes: gram-negative resistant bacteria, 10 studies; Clostridium difficile-associated diarrhea, 5 studies; vancomycin-resistant enterococci, 3 studies; and methicillin-resistant Staphylococcus aureus, 2 studies. Four studies provided strong evidence that the intervention changed microbial outcomes with low risk for alternative explanations, 8 studies provided less convincing evidence, and 4 studies provided no evidence. The strongest and most consistent evidence was for C. difficile-associated diarrhea, but we were able to analyze only the immediate impact of interventions because of nonstandardized durations of follow-up. The ability to compare results of studies could be substantially improved by standardizing methods and reporting.

Comparison of antimicrobial cycling and mixing strategies in two medical intensive care units*

OBJECTIVE

To compare a mixing vs. a cycling strategy of use of anti-Pseudomonas antibiotics on the acquisition of resistant Gram-negative bacilli in the critical care setting.

DESIGN

Prospective, open, comparative study of two strategies of antibiotic use.

SETTING

Two medical intensive care units of a university hospital.

PATIENTS

A total of 346 patients admitted for >or=48 hrs to two separate medical intensive care units during an 8-month period.

INTERVENTIONS

Patients, who according to the attending physician's judgment required an anti-Pseudomonas regimen, were assigned to receive cefepime/ceftazidime, ciprofloxacin, a carbapemen, or piperacillin-tazobactam in this order. "Cycling" was accomplished by prescribing one of these antibiotics during 1 month each. "Mixing" was accomplished by using the same order of antibiotic administration on consecutive patients. Interventions were carried out during two successive 4-month periods, starting with mixing in one unit and cycling in the other.

MEASUREMENTS AND MAIN RESULTS

Swabbing of nares, pharynx, and rectum and culture of respiratory secretions were obtained thrice weekly. The main outcome variable was the proportion of patients acquiring enteric or nonfermentative Gram-negative bacilli resistant to the antibiotics under intervention. The scheduled cycling of antibiotics was only partially successful. Although the expected antibiotic was the most prevalent anti-Pseudomonas agent used within the corresponding period, it never accounted for >45% of all anti-Pseudomonas antimicrobials administered. During mixing, a significantly higher proportion of patients acquired a strain of Pseudomonas aeruginosa resistant to cefepime (9% vs. 3%, p = .01), and there was a trend toward a more frequent acquisition of resistance to ceftazidime (p = .06), imipenem (p = .06), and meropenem (p = .07). No differences in the rate of acquisition of potentially resistant Gram-negative bacilli or incidence of intensive care unit-acquired infections and infections due to particular organisms were observed.

CONCLUSIONS

In critically ill medical patients, a strategy of monthly rotation of anti-Pseudomonas beta-lactams and ciprofloxacin may perform better than a strategy of mixing in the acquisition of P. aeruginosa resistant to selected beta-lactams.

Infection control, hospital epidemiology, and patient safety

Health care-acquired are a major risk for hospitalized children. Similar to adult patients, children are vulnerable to infections related to medical devices. Children also are at significant risk of nosocomial transmission of common pediatric viral illness, such as respiratory syncytial virus and varicella. In addition, pediatric patients have unique or incompletely developed immune system.

Unnatural selection: reducing antibiotic resistance in neonatal units

Antibiotic use selects for antibiotic resistant bacteria. This is an example of rapid Darwinian natural selection in action. It occurs in neonatal intensive care units with the use of parenteral antibiotics, and in the community with oral antibiotic use. A 10 point plan is put forward to reduce antibiotic resistance in neonatal units.

Interventions to improve antibiotic prescribing practices for hospital inpatients

BACKGROUND

Up to 50% of antibiotic usage in hospitals is inappropriate. In hospitals infections caused by antibiotic-resistant bacteria are associated with higher mortality, morbidity and prolonged hospital stay compared with infections caused by antibiotic-susceptible bacteria. Clostridium difficile associated diarrhoea (CDAD) is a hospital acquired infection that is caused by antibiotic prescribing.

OBJECTIVES

To estimate the effectiveness of professional interventions that alone, or in combination, are effective in promoting prudent antibiotic prescribing to hospital inpatients, to evaluate the impact of these interventions on reducing the incidence of antimicrobial resistant pathogens or CDAD and their impact on clinical outcome.

SEARCH STRATEGY

We searched the Cochrane Effective Practice and Organisation of Care (EPOC) specialized register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE from 1980 to November 2003. Additional studies were obtained from the bibliographies of retrieved articles

SELECTION CRITERIA

We included all randomised and controlled clinical trials (RCT/CCT), controlled before and after studies (CBA) and interrupted time series (ITS) studies of antibiotic prescribing to hospital inpatients. Interventions included any professional or structural interventions as defined by EPOC.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data and assessed quality.

MAIN RESULTS

Sixty six studies were included and 51 (77%) showed a significant improvement in at least one outcome. Six interventions only aimed to increase treatment, 57 interventions aimed to decrease treatment and three interventions aimed to both increase and decrease treatment. The intervention target was the decision to prescribe antibiotics (one study), timing of first dose (six studies), the regimen (drug, dosing interval etc, 61 studies) or the duration of treatment (10 studies); 12 studies had more than one target. Of the six interventions that aimed to increase treatment, five reported a significant improvement in drug outcomes and one a significant improvement in clinical outcome. Of the 60 interventions that aimed to decrease treatment 47 reported drug outcomes of which 38 (81%) significantly improved, 16 reported microbiological outcomes of which 12 (75%) significantly improved and nine reported clinical outcomes of which two (22%) significantly deteriorated and 3 (33%) significantly improved. Five studies aimed to reduce CDAD. Three showed a significant reduction in CDAD. Due to differences in study design and duration of follow up it was only possible to perform meta-regression on a few studies.

AUTHORS' CONCLUSIONS

The results show that interventions to improve antibiotic prescribing to hospital inpatients are successful, and can reduce antimicrobial resistance or hospital acquired infections.

Antibiotic cycling: more than it might seem?

In the present battle against the rising tide of resistance, several interventions have been proposed to help control the situation. One of these is a process of planned antibiotic restriction, introduced through cycling drug selection based on local surveillance. Although such antibiotic cycling has been the subject of much discussion for 20 years, there are relatively few data available to assess its worth. A recent systematic review found only four studies worthy of inclusion and concluded that antibiotic cycling could not, at present, be promoted as a methodology to control resistance. This paper considers the complete literature and through demonstrating consistent benefits across the breadth and depth of the findings, suggests that whereas further work is required, nevertheless antibiotic cycling-as part of a suite of control measures-is a valid option.

Antibiotic cycling or rotation: a systematic review of the evidence of efficacy

Of the interventions designed to reduce antibiotic resistance rates in hospitals, one that is currently attracting considerable interest, particularly in the intensive care unit setting, is antibiotic cycling or rotation. Cycling is the scheduled rotation of one class of antibiotics with one or more different classes exhibiting comparable spectra of activity; in order to fulfil the definition, the cycle must be repeated. Following a search of the literature we identified 11 articles in which the authors claimed to have evaluated the efficacy of this intervention. Only four were suitable for review, but, owing to multiple methodological flaws and a lack of standardization, the results of these studies do not permit reliable conclusions regarding the efficacy of cycling. Further studies are therefore required in order to resolve this question. However, before such studies can be undertaken, there are a great many issues relating to cycling which must be addressed. For the time being, we advise against the routine implementation of this measure as a means of reducing antibiotic resistance rates.

Ecological theory suggests that antimicrobial cycling will not reduce antimicrobial resistance in hospitals

Hospital-acquired infections caused by antibiotic-resistant bacteria pose a grave and growing threat to public health. Antimicrobial cycling, in which two or more antibiotic classes are alternated on a time scale of months to years, seems to be a leading candidate in the search for treatment strategies that can slow the evolution and spread of antibiotic resistance in hospitals. We develop a mathematical model of antimicrobial cycling in a hospital setting and use this model to explore the efficacy of cycling programs. We find that cycling is unlikely to reduce either the evolution or the spread of antibiotic resistance. Alternative drug-use strategies such as mixing, in which each treated patient receives one of several drug classes used simultaneously in the hospital, are predicted to be more effective. A simple ecological explanation underlies these results. Heterogeneous antibiotic use slows the spread of resistance. However, at the scale relevant to bacterial populations, mixing imposes greater heterogeneity than does cycling. As a consequence, cycling is unlikely to be effective and may even hinder resistance control. These results may explain the limited success reported thus far from clinical trials of antimicrobial cycling.

Epidemiology and control of antibiotic resistance in the intensive care unit

PURPOSE OF REVIEW

Resistance to antibiotics is very high in the intensive care units of many countries, although there are several exceptions. Some infections are becoming extremely difficult to treat. The risk of cross-transmission of those strains is very high. This review focuses on recent data (2003 to the present) that may help understanding and dealing with this serious public health problem.

RECENT FINDINGS

Intensive care units can be considered as 'factories' for creating, disseminating and amplifying resistance to antibiotics, for many reasons: importation of resistant microorganisms at admission, selection of resistant strains with an extensive use of broad-spectrum antibiotics, cross-transmission of resistant strains via the hands or the environment. Some national programs can be considered as failures, as in the UK and the USA. Other countries have been able to maintain a low level of resistance (Scandinavian countries, Netherlands, Switzerland, Germany, Canada). There is clearly an 'inoculum effect' above which preventive measures become poorly efficient. Several preventive measures have been proposed including preventive isolation, systematic screening at admission, local, national or international antibiotic guidelines, antibiotic prescriptions advice by infectious-disease teams, antibiotic prevention with selective digestive decontamination, antibiotic strategies such as 'cycling', or rather, for some authors, the use of an 'à la carte' antibiotic strategy which could be considered as a 'patient-to-patient antibiotic rotation'.

SUMMARY

There is obviously an international concern regarding the level of resistance to antibiotics in the intensive-care-unit setting. A strong program including prevention of cross-transmission and better usage of antibiotics seems to be needed in order to be successful. We do not know if this kind of program will enable countries with a very high endemic level of resistance to decrease the level in future years.

Antibiotic-resistant gram-negative bacteria in hospitalized children

Antibiotic-resistant Gram-negative bacilli are a prominent and growing problem among hospitalized children. Epidemics caused by these organisms have been implicated in many outbreaks in children's hospitals, primarily in neonatal intensive care units. These epidemics are characterized by efficient patient-to-patient transmission of the outbreak clone via the hands of caregivers and through exposure of contaminated inanimate sources. The epidemiology of these resistant organisms in pediatric hospitals during endemic periods is more complex. The isolates cultured from hospitalized individuals in the absence of an outbreak usually are unique to each individual and are derived from the patient's endogenous flora or other disparate sources. As in adults, chronic care facilities for children represent significant reservoirs of antibiotic-resistant bacilli that are circulated back into the acute care hospital environment when the child becomes ill.

Strategic use of antibiotics in the neonatal intensive care unit

Infection is one of the most common causes of infant morbidity and mortality in the neonatal intensive care unit, despite the availability of various therapeutic medical interventions, such as mechanical ventilation, that allow premature infants a better chance of survival. In fact, many of these therapeutic interventions violate the natural protective barriers for infection. Fortunately, maternal and neonatal risk factors have been identified for early- and late-onset sepsis and the prevalence of highly suspected pathogens for each type of infection influences the empiric selection of antibiotics. In many institutions, the common pathogens have developed resistance to antibiotics. In others, the predominance of pathogens has shifted. Both challenges may warrant modification of traditional antibiotic regimens. Continual monitoring of pathogen shifts within an individual neonatal intensive care unit and application of various antibiotic characteristics are key elements of strategic, safe, and effective use of antibiotics in this patient population. Development of a protocol incorporating infection control measures and guidelines for judicious use of antibiotics can minimize the threat of antibiotic resistance.