The Effect of a Nationwide Infection Control Program Expansion on Hospital-Onset Gram-Negative Rod Bacteremia in 130 Veterans Health Administration Medical Centers: An Interrupted Time-Series Analysis

Are Contact Precautions "Essential" for the Prevention of Healthcare-associated Methicillin-Resistant Staphylococcus aureus?

The recently updated Society for Healthcare Epidemiology of America, the Infectious Diseases Society of America, and the Association of Professionals in Infection Control practice recommendations for methicillin-resistant Staphylococcus aureus (MRSA) prevention in acute care facilities list contact precautions (CPs) for patients known to be infected or colonized with MRSA as an "essential practice," meaning that it should be adopted in all acute care facilities. We argue that existing evidence on benefits and harms associated with CP do not justify this recommendation. There are no controlled trials that support broad use of CP for MRSA prevention. Data from hospitals that have discontinued CP for MRSA have found no impact on MRSA acquisition or infection. The burden and harms of CP remain concerning, including the environmental impact of increased gown and glove use. We suggest that CP be included among other "additional approaches" to MRSA prevention that can be implemented under specific circumstances (eg outbreaks, evidence of ongoing transmission despite application of essential practices).

14-Year Epidemiologic study of Pseudomonas aeruginosa bloodstream infection incidence and resistance in the Veterans Health Administration system, 2009-2022

Background

Multidrug resistant Pseudomonas aeruginosa (PA) represents a serious threat to hospitalized patients. Characterizing the incidence of PA infection and degree of resistance can inform empiric treatment and preventative measures.

Objectives

We sought to describe trends in incidence and resistance characteristics of PA bloodstream infections (BSI) observed within the Veterans Health Administration (VHA) system and identify factors contributing to higher observed mortality within this population.

Methods

We characterized demographic and clinical features of unique patients among the VHA population presenting with their first episode of PA-BSI between 2009 and 2022 and summarized trends related to mortality and resistance phenotype based on year and geographical location. We additionally used logistic regression analysis to identify predictors of 30-day mortality among this cohort.

Results

We identified 8039 PA-BSIs during the study period, 32.7% of which were hospital onset. Annual PA-BSI cases decreased by 35.8%, and resistance among all antimicrobial classes decreased during the study period, while the proportion of patients receiving early active treatment based on susceptibility testing results increased. Average 30-day mortality rate was 23.3%. Higher Charlson Comorbidity Index, higher mAPACHE score, VHA facility complexity 1b and hospital-onset cases were associated with higher mortality, and early active treatment was associated with lower mortality.

Conclusions

PA-BSI resistance decreased across the VHA system during the study period. Further investigation of antimicrobial stewardship measures possibly contributing to the observed decreased resistance in this cohort and identification of measures to improve on the high mortality associated with PA-BSI in the VHA population is warranted.

Etiology and utility of hospital-onset bacteremia as a safety metric for targeted harm reduction

BACKGROUND

Hospital acquired infections (HAIs) are a major driver of morbidity and cost in health systems. Central line-associated bloodstream infections (CLABSIs) require intensive surveillance and review. All-cause hospital-onset bacteremia (HOB) may be a simpler reporting metric, correlates with CLABSI, and is viewed positively by HAI experts. Despite the ease in the collection, the proportion of HOBs that are actionable and preventable is unknown. Moreover, quality improvement strategies targeting it may be more challenging. In this study, we describe the bedside provider-perceived sources of HOB in order to provide insight into this new metric as a target for HAI prevention.

METHODS

All cases of HOBs in 2019 from an academic tertiary care hospital were retrospectively reviewed. Information was collected to assess provider-perceived etiology and associated clinical factors (microbiology, severity, mortality, and management). HOB was categorized as preventable or not preventable based on the perceived source from the care team and management decisions. Preventable causes included device-associated bacteremias, pneumonias, surgical complications, and contaminated blood cultures.

RESULTS

Of the 392 instances of HOB, 56.0% (n = 220) had episodes that were determined not preventable by providers. Excluding blood culture contaminates, the most common cause of preventable HOB was secondary to CLABSIs (9.9%, n = 39). Of the HOBs that were not preventable, the most common sources were gastrointestinal and abdominal (n = 62), neutropenic translocation (n = 37), and endocarditis (n = 23). Patients with HOB were generally medically complex with an average Charlson comorbidity index of 4.97. This translated into a higher average length of stay (29.23 vs 7.56, P < .001) and higher inpatient mortality (odds ratio 8.3, confidence interval [6.32-10.77]) when compared to admissions without HOB.

CONCLUSIONS

The majority of HOBs were not preventable and the HOB metric may be a marker of a sicker patient population making it a less actionable target for quality improvement. Standardization across the patient mix is important if the metric becomes linked to reimbursement. If the HOB metric were to be used in lieu of CLABSI, large tertiary care health systems that house sicker patients may be unfairly financially penalized for caring for more medically complex patients.

Decreasing Antibiotic Resistance Trends Nationally in Gram-Negative Bacteria Across United States Veterans Affairs Medical Centers, 2011-2020

INTRODUCTION

Gram-negative resistance is a well-acknowledged public health threat. Surveillance data can be used to monitor resistance trends and identify strategies to mitigate their threat. The objective of this study was to assess antibiotic resistance trends in Gram-negative bacteria.

METHODS

The first cultures of Pseudomonas aeruginosa, Citrobacter, Escherichia coli, Enterobacter, Klebsiella, Morganella morganii, Proteus mirabilis, and Serratia marcescens per hospitalized patient per month collected from 125 Veterans Affairs Medical Centers (VAMCs) between 2011 to 2020 were included. Time trends of resistance phenotypes (carbapenem, fluoroquinolone, extended-spectrum cephalosporin, multi-drug, and difficult-to-treat) were analyzed with Joinpoint regression to estimate average annual percent changes (AAPC) with 95% confidence intervals and p values. A 2020 antibiogram of reported antibiotic percent susceptibilities was also created to evaluate resistance rates at the beginning of the COVID-19 pandemic.

RESULTS

Among 40 antimicrobial resistance phenotype trends assessed in 494,593 Gram-negative isolates, there were no noted increases; significant decreases were observed in 87.5% (n = 35), including in all P. aeruginosa, Citrobacter, Klebsiella, M. morganii, and S. marcescens phenotypes (p < 0.05). The largest decreases were seen in carbapenem-resistant phenotypes of P. mirabilis, Klebsiella, and M. morganii (AAPCs: - 22.9%, - 20.7%, and - 20.6%, respectively). In 2020, percent susceptibility was over 80% for all organisms tested against aminoglycosides, cefepime, ertapenem, meropenem, ceftazidime-avibactam, ceftolozane-tazobactam, and meropenem-vaborbactam.

CONCLUSION

We observed significant decreases in antibiotic resistance for P. aeruginosa and Enterobacterales over the past decade. According to the 2020 antibiogram, in vitro antimicrobial activity was observed for most treatment options. These results may be related to the robust infection control and antimicrobial stewardship programs instituted nationally among VAMCs.

Healthcare-associated infections in Veterans Affairs acute-care and long-term healthcare facilities during the coronavirus disease 2019 (COVID-19) pandemic

OBJECTIVE

To assess the impact of the coronavirus disease 2019 (COVID-19) pandemic on healthcare-associated infections (HAIs) reported from 128 acute-care and 132 long-term care Veterans Affairs (VA) facilities.

METHODS

We compared central-line-associated bloodstream infections (CLABSIs), ventilator-associated events (VAEs), catheter-associated urinary tract infections (CAUTIs), methicillin-resistant Staphylococcus aureus (MRSA), and Clostridioides difficile infections and rates reported from each facility monthly to a centralized database before the pandemic (February 2019 through January 2020) and during the pandemic (July 2020 through June 2021).

RESULTS

Nationwide VA COVID-19 admissions peaked in January 2021. Significant increases in the rates of CLABSIs, VAEs, and MRSA all-site HAIs (but not MRSA CLABSIs) were observed during the pandemic in acute-care facilities. There was no significant change in CAUTI rates, and C. difficile rates significantly decreased. There were no significant increases in HAIs in long-term care facilities.

CONCLUSIONS

The COVID-19 pandemic had a differential impact on HAIs of various types in VA acute care, with many rates increasing. The decrease in CDI HAIs may be due, in part, to evolving diagnostic testing. The minimal impact of COVID-19 in VA long-term facilities may reflect differences in patient numbers and acuity and early recognition of the impact of the pandemic on nursing home residents leading to increased vigilance and optimization of infection prevention and control practices in that setting. These data support the need for building and sustaining conventional infection prevention and control strategies before and during a pandemic.

Effectiveness of Ultraviolet-C Disinfection on Hospital-Onset Gram-Negative Rod Bloodstream Infection: A Nationwide Stepped-Wedge Time-Series Analysis

BACKGROUND

The effectiveness of enhanced terminal room cleaning with ultraviolet C (UV-C) disinfection in reducing gram-negative rod (GNR) infections has not been well evaluated. We assessed the association of implementation of UV-C disinfection systems with incidence rates of hospital-onset (HO) GNR bloodstream infection (BSI).

METHODS

We obtained information regarding UV-C use and the timing of implementation through a survey of all Veterans Health Administration (VHA) hospitals providing inpatient acute care. Episodes of HO-GNR BSI were identified between January 2010 and December 2018. Bed days of care (BDOC) was used as the denominator. Over-dispersed Poisson regression models were fitted with hospital-specific random intercept, UV-C disinfection use for each month, baseline trend, and seasonality as explanatory variables. Hospitals without UV-C use were also included to the analysis as a nonequivalent concurrent control group.

RESULTS

Among 128 VHA hospitals, 120 provided complete survey responses with 40 reporting implementations of UV-C systems. We identified 13 383 episodes of HO-GNR BSI and 24 141 378 BDOC. UV-C use was associated with a lower incidence rate of HO-GNR BSI (incidence rate ratio: 0.813; 95% confidence interval: .656-.969; P = .009). There was wide variability in the effect size of UV-C disinfection use among hospitals.

CONCLUSIONS

In this large quasi-experimental analysis within the VHA System, enhanced terminal room cleaning with UV-C disinfection was associated with an approximately 19% lower incidence of HO-GNR BSI, with wide variability in effectiveness among hospitals. Further studies are needed to identify the optimal implementation strategy to maximize the effectiveness of UV-C disinfection technology.

Effects of screening strategies to detect carbapenem-resistant gram-negative bacteria: A systematic review

OBJECTIVE

This systematic review aims to summarize the evidence on the effects of screening strategies to detect carbapenem-resistant gram-negative bacteria (Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa).

METHODS

Eligible studies were randomized trials, non-randomized controlled trials, controlled before-after studies, and interrupted time series. We conducted searches in CENTRAL, PUBMED, Embase, Epistemonikos, and in multiple databases available in the Virtual Health Library (LILACS, Scielo, WHO IBECS, and PAHO IBECS). All the searches covered the period until 4 June 2021. No date or language restrictions were applied. Two reviewers independently evaluated potentially eligible studies according to predefined selection criteria, and extracted data on study characteristics, methods, outcomes, and risk of bias, using a predesigned standardized form. When possible, we intended to conduct meta-analyses using a random-effect model. We assessed the certainty of the evidence (CoE) and summarized the results using the GRADE approach.

RESULTS

Our search strategy yielded 57,451 references. No randomized trials were identified. Sixteen studies (one controlled before-after study and 15 interrupted time series) met our inclusion criteria and were included in the review. Most studies were conducted in tertiary care general hospitals from the United States, Europe, and Asia. Eleven studies included adult patients hospitalized in general wards and intensive care units, one was carried out in a neonatal intensive care unit, two in hematology or oncology units, and one in a solid organ transplantation department. Eleven studies were conducted in the setting of an outbreak. Regarding the detection strategy used, all studies included screening strategies for high-risk patients at the moment of admission and 7 studies reported a contact surveillance strategy. Most studies were conducted in settings where infection prevention and control measures were concomitantly installed or reinforced. Data were not suitable for meta-analysis, so the results were presented as a narrative synthesis. Most studies showed a decline in the prevalence of both infection and colonization rates after the implementation of a policy of active surveillance, but the CoE is low. Screening strategies may result in little to no difference in the risk of all-cause mortality and the length of hospital stay.

CONCLUSIONS

Existing evidence may favor the use of surveillance culture to carbapenem-resistant gram-negative bacteria, but its quality is poor, so solid conclusions cannot be drawn. Well-conducted randomized trials or high-quality quasi-experimental studies are needed to improve the certainty of the existing evidence. These studies should assess the effect of the addition of screening strategies as a single intervention and measure clinically important outcomes such as infection, length of hospital stay, and mortality.

Trends in Stenotrophomonas maltophilia antibiotic resistance rates in the United States Veterans Affairs Health System

Introduction. Stenotrophomonas maltophilia is an important multidrug-resistant Gram-negative pathogen. While largely a hospital-acquired pathogen, there have been increasing reports of the pathogen in the community.

Gap Statement. Trends in S. maltophilia prevalence and resistance rates that include outpatient isolates are unknown.

Aim. We described recent trends in prevalence and resistance of S. maltophilia in the national Veterans Affairs (VA) Healthcare system.

Methodology. The study identified positive S. maltophilia clinical cultures among VA adult patients from 2010 to 2018 across all VA hospitals, long-term care facilities/units, and outpatient settings. Annual S. maltophilia resistance rates were evaluated. Multidrug resistant (MDR) was defined as resistance to sulfamethoxazole/trimethoprim (SMX/TMP) and minocycline or levofloxacin. Time trends were assessed with regression analyses to estimate annual average percent changes (AAPC) with 95 % confidence intervals using Joinpoint software.

Results. Over the 9 year study period, 18 285  S . maltophilia cultures were identified (57 % hospital, 3 % long-term care, 40 % outpatient). The most common source of S. maltophilia cultures were respiratory cultures (34.6 %) followed by urine cultures (30.4 %). In VA hospitals and long-term care facilities, the number of S. maltophilia cultures decreased significantly (by 5.4% and 8.4 % per year respectively). Overall, 3.1 % of isolates were MDR which remained stable over the study period. Resistance to other antibiotics assessed mostly remained stable, except SMX/TMP resistance decreased significantly by 8.5 % (2010, 15 %; 2018, 6 %) per year in VA hospitals.

Conclusion. While previous work has recognized S. maltophilia as primarily a nosocomial pathogen, the present study found that 40 % of cultures collected were among outpatients. Between 2010 and 2018, the number of positive S. maltophilia cultures decreased significantly in the national VA Healthcare System. Resistance to SMX/TMP decreased over the study period in VA hospitals and now more closely reflects previously reported resistance rates worldwide (0–10 %). MDR S. maltophilia remained stable and low in the national VA Healthcare System.

Epidemiology and outcomes associated with carbapenem-resistant Acinetobacter baumannii and carbapenem-resistant Pseudomonas aeruginosa: a retrospective cohort study

Background

Carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) are a growing threat. The objective of this study was to describe CRAB and CRPA epidemiology and identify factors associated with mortality and length of stay (LOS) post-culture.

Methods

This was a national retrospective cohort study of Veterans with CRAB or CRPA positive cultures from 2013 to 2018, conducted at Hines Veterans Affairs Hospital. Carbapenem resistance was defined as non-susceptibility to imipenem, meropenem and/or doripenem. Multivariable cluster adjusted regression models were fit to assess the association of post-culture LOS among inpatient and long-term care (LTC) and to identify factors associated with 90-day and 365-day mortality after positive CRAB and CRPA cultures.

Results

CRAB and CRPA were identified in 1,048 and 8,204 unique patients respectively, with 90-day mortality rates of 30.3% and 24.5% and inpatient post-LOS of 26 and 27 days. Positive blood cultures were associated with an increased odds of 90-day mortality compared to urine cultures in patients with CRAB (OR 6.98, 95% CI 3.55–13.73) and CRPA (OR 2.82, 95% CI 2.04–3.90). In patients with CRAB and CRPA blood cultures, higher Charlson score was associated with increased odds of 90-day mortality. In CRAB and CRPA, among patients from inpatient care settings, blood cultures were associated with a decreased LOS compared to urine cultures.

Conclusions

Positive blood cultures and more comorbidities were associated with higher odds for mortality in patients with CRAB and CRPA. Recognizing these factors would encourage clinicians to treat these patients in a timely manner to improve outcomes of patients infected with these organisms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07436-w.

National trends in hospital, long-term care and outpatient Acinetobacter baumannii resistance rates

Introduction. Acinetobacter baumannii is a top-priority pathogen of the World Health Organization (WHO) and the Centers for Disease Control (CDC) due to antibiotic resistance.Gap Statement. Trends in A. baumannii resistance rates that include community isolates are unknown.Aim. Identify trends in A. baumannii resistance rates across the Veterans Affairs (VA) Healthcare System, including isolates from patients treated in hospitals, long-term care facilities and outpatient clinics nationally.Methodology. We included A. baumannii clinical cultures collected from VA patients from 2010 to 2018. Cultures were categorized by location: VA medical centers (VAMCs), long-term care (LTC) units [community living centers (CLCs)], or outpatient. We assessed carbapenem resistance, multidrug resistance (MDR) and extensive drug resistance (XDR). Time trends were assessed with Joinpoint regression.Results. We identified 19 376 A. baumannii cultures (53% VAMCs, 4% CLCs, 43% outpatient). Respiratory cultures were the most common source of carbapenem-resistant (43 %), multidrug-resistant (49 %) and extensively drug-resistant (21 %) isolates. Over the study period, the number of A. baumannii cultures decreased significantly in VAMCs (11.9% per year). In 2018, carbapenem resistance was seen in 28% of VAMC isolates and 36% of CLC isolates, but only 6% of outpatient isolates, while MDR was found in 31% of VAMC isolates and 36% of CLC isolates, but only 8 % of outpatient isolates. Carbapenem-resistant, multidrug-resistant and extensively drug-resistant A. baumannii isolates decreased significantly in VAMCs and outpatient clinics over time (VAMCs: by 4.9, 7.2 and 6.9%; outpatient: by 11.3, 10.5 and 10.2% per year). Resistant phenotypes remained stable in CLCs.Conclusion. In the VA nationally, the prevalence of A. baumannii is decreasing, as is resistance. Carbapenem-resistant and multidrug-resistant A. baumannii remain common in VAMCs and CLCs. The focus of infection control and antimicrobial stewardship efforts to prevent transmission of resistant A. baumannii should be in hospital and LTC settings.

A Multicenter Clinical Study To Demonstrate the Diagnostic Accuracy of the GenMark Dx ePlex Blood Culture Identification Gram-Negative Panel

Bacteremia can progress to septic shock and death without appropriate medical intervention. Increasing evidence supports the role of molecular diagnostic panels in reducing the clinical impact of these infections through rapid identification of the infecting organism and associated antimicrobial resistance genes. We report the results of a multicenter clinical study assessing the performance of the GenMark Dx ePlex investigational-use-only blood culture identification Gram-negative panel (BCID-GN), a rapid diagnostic assay for detection of bloodstream pathogens in positive blood culture (PBC) bottles. Prospective, retrospective, and contrived samples were tested. Results from the BCID-GN were compared to standard-of-care bacterial identification methods. Antimicrobial resistance genes (ARGs) were identified using PCR and sequence analysis. The final BCID-GN analysis included 2,444 PBC samples, of which 926 were clinical samples with negative Gram stain results. Of these, 109 samples had false-negative and/or -positive results, resulting in an overall sample accuracy of 88.2% (817/926). After discordant resolution, overall sample accuracy increased to 92.9% (860/926). Pre- and postdiscordant resolution sample accuracy excludes 37 Gram-negative organisms representing 20 uncommon genera, 10 Gram-positive organisms, and 1 Candida species present in 5% of samples that are not targeted by the BCID-GN. The overall weighted positive percent agreement (PPA), which averages the individual PPAs from the 27 targets (Gram-negative and ARG), was 94.9%. The limit of detection ranged from 10⁴ to 10⁷ CFU/ml, except for one strain of Fusobacterium necrophorum at 10⁸ CFU/ml.

Expanding an Economic Evaluation of the Veterans Affairs (VA) Methicillin-resistant Staphylococcus aureus (MRSA) Prevention Initiative to Include Prevention of Infections From Other Pathogens

BACKGROUND

In October 2007, Veterans Affairs (VA) launched a nationwide effort to reduce methicillin-resistant Staphylococcus aureus (MRSA) transmission called the National MRSA Prevention Initiative. Although the initiative focused on MRSA, recent evidence suggests that it also led to a significant decrease in hospital-onset (HO) gram-negative rod (GNR) bacteremia, vancomycin-resistant Enterococci (VRE), and Clostridioides difficile infections. The objective of this analysis was to evaluate the cost-effectiveness and the budget impact of the initiative taking into account MRSA, GNR, VRE, and C. difficile infections.

METHODS

We developed an economic model using published data on the rate of MRSA hospital-acquired infections (HAIs) and HO-GNR bacteremia in the VA from October 2007 to September 2015, estimates of the attributable cost and mortality of these infections, and the costs associated with the intervention obtained through a microcosting approach. We explored several different assumptions for the rate of infections that would have occurred if the initiative had not been implemented. Effectiveness was measured in life-years (LYs) gained.

RESULTS

We found that during fiscal years 2008-2015, the initiative resulted in an estimated 4761-9236 fewer MRSA HAIs, 1447-2159 fewer HO-GNR bacteremia, 3083-3602 fewer C. difficile infections, and 2075-5393 fewer VRE infections. The initiative itself was estimated to cost $561 million over this 8-year period, whereas the cost savings from prevented MRSA HAIs ranged from $165 to $315 million and from prevented HO-GNR bacteremia, CRE and C. difficile infections ranged from $174 to $200 million. The incremental cost-effectiveness of the initiative ranged from $12 146 to $38 673/LY when just including MRSA HAIs and from $1354 to $4369/LY when including the additional pathogens. The overall impact on the VA's budget ranged from $67 to$195 million.

CONCLUSIONS

An MRSA surveillance and prevention strategy in VA may have prevented a substantial number of infections from MRSA and other organisms. The net increase in cost from implementing this strategy was quite small when considering infections from all types of organisms. Including spillover effects of organism-specific prevention efforts onto other organisms can provide a more comprehensive evaluation of the costs and benefits of these interventions.

Temporal Trends of Candidemia Incidence Rates and Potential Contributions of Infection Control Initiatives over 18 Years within the US Veteran Health Administration System: A Joinpoint Time-Series Analysis

BACKGROUND

Candidemia is one of the most common causes of nosocomial bloodstream infections, but the impacts of factors affecting its incidence have not been evaluated.

METHODS

We analyzed a retrospective cohort of all candidemia patients at 130 acute care hospitals in the Veterans Health Administration (VHA) system from January 2000 through December 2017. Cases were classified as hospital-onset (HO) and non-hospital-onset (NHO). We used Joinpoint regression analysis to assess temporal associations between significant changes in candidemia incidence rates and guidelines or horizontal infection control (IC) interventions.

RESULTS

Over 18 years, 17,661 candidemia episodes were identified. Incidence rates of HO cases were increasing until the mid-2000s, followed by a sustained decline, while NHO cases showed a steady decline. The first change in HO candidemia incidence rates (8/2004 [95% CI: 2/2003-4/2005]) was preceded by the publication of catheter-related bloodstream infection (CRBSI) prevention guidelines and the CRBSI surveillance initiation. The second (9/2007 [95% CI: 9/2006-6/2009]) had close temporal proximity to the expansion of IC resources within the VHA system. Collectively, these trend changes resulted in a 77.1% reduction in HO candidemia incidence rates since its peak in 2004.

CONCLUSIONS

A substantial and sustained systemwide reduction in candidemia incidence rates was observed after the publication of guidelines, VHA initiatives about CRBSI reporting and education on CRBSI prevention, and the systemwide expansion of IC resources.

Reductions in Methicillin-resistant Staphylococcus aureus, Clostridium difficile Infection and Intensive Care Unit-Acquired Bloodstream Infection Across the United Kingdom Following Implementation of a National Infection Control Campaign

Background

Methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile infections declined across the UK National Health Service in the decade that followed implementation of an infection control campaign. The national impact on intensive care unit (ICU)-acquired infections has not been documented.

Methods

Data on MRSA, C. difficile, vancomycin-resistant Enterococcus (VRE), and ICU–acquired bloodstream infections (UABSIs) for 1 189 142 patients from 2007 to 2016 were analyzed. Initial coverage was 139 ICUs increasing to 276 ICUs, representing 100% of general adult UK ICUs.

Results

ICU MRSA and C. difficile acquisitions per 1000 patients decreased between 2007 and 2016 (MRSA acquisitions, 25.4 to 4.1; and C. difficile acquisitions, 11.1 to 3.5), whereas VRE acquisitions increased from 1.5 to 5.9. There were 13 114 UABSIs in 1.8% of patients who stayed longer than 48 hours on ICU. UABSIs fell from 7.3 (95% confidence interval [CI], 6.9–7.6) to 1.6 (95% CI, 1.5–1.7)/1000 bed days. Adjusting for patient factors, the incidence rate ratio was 0.21 (95% CI, 0.19–0.23, P < .001) from 2007 to 2016. The greatest reduction, comparing rates in 2007/08 and 2015/16, was for MRSA (97%), followed by P. aeruginosa (81%), S. aureus (79%) and Candida spp (72%), with lower reductions for the coliforms (E. coli 57% and Klebsiella 49%).

Conclusions

Large decreases in ICU-acquired infections occurred across the UK ICU network linked with the first few years of a national infection control campaign, but rates have since been static. Further reductions will likely require a new intervention framework.

Epidemiology and clinical outcomes associated with extensively drug-resistant (XDR) Acinetobacter in US Veterans' Affairs (VA) medical centers

OBJECTIVE

Although infections caused by Acinetobacter baumannii are often healthcare-acquired, difficult to treat, and associated with high mortality, epidemiologic data for this organism are limited. We describe the epidemiology, clinical characteristics, and outcomes for patients with extensively drug-resistant Acinetobacter baumannii (XDRAB).

DESIGN

Retrospective cohort study.

SETTING

Department of Veterans' Affairs Medical Centers (VAMCs).

PARTICIPANTS

Patients with XDRAB cultures (defined as nonsusceptible to at least 1 agent in all but 2 or fewer classes) at VAMCs between 2012 and 2018.

METHODS

Microbiology and clinical data was extracted from national VA datasets. We used descriptive statistics to summarize patient characteristics and outcomes and bivariate analyses to compare outcomes by culture source.

RESULTS

Among 11,546 patients with 15,364 A. baumannii cultures, 408 (3.5%) patients had 667 (4.3%) XDRAB cultures. Patients with XDRAB were older (mean age, 68 years; SD, 12.2) with median Charlson index 3 (interquartile range, 1-5). Respiratory specimens (n = 244, 36.6%) and urine samples (n = 187, 28%) were the most frequent sources; the greatest proportion of patients were from the South (n = 162, 39.7%). Most patients had had antibiotic exposures (n = 362, 88.7%) and hospital or long-term care admissions (n = 331, 81%) in the prior 90 days. Polymyxins, tigecycline, and minocycline demonstrated the highest susceptibility. Also, 30-day mortality (n = 96, 23.5%) and 1-year mortality (n = 199, 48.8%) were high, with significantly higher mortality in patients with blood cultures.

CONCLUSIONS

The proportion of Acinetobacter baumannii in the VA that was XDR was low, but treatment options are extremely limited and clinical outcomes were poor. Prevention of healthcare-associated XDRAB infection should remain a priority, and novel antibiotics for XDRAB treatment are urgently needed.

Healthcare facility-onset, healthcare facility-associated Clostridioides difficile infection in Veterans with spinal cord injury and disorder

Objective: To describe the burden and risk of healthcare facility-onset, healthcare facility-associated (HO-HCFA) Clostridioides difficile infection (CDI) in Veterans with spinal cord injury and disorder (SCI/D). Design: Retrospective, longitudinal cohort study from October 1, 2001-September 30, 2010. Setting: Ninety-four acute care Veterans Affairs facilities. Participants: Patients with SCI/D. Outcomes: Incidence rate of HO-HCFA CDI. Methods: Rates of CDI were determined, and crude unadjusted incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were calculated. Multivariable Poisson random-effects regression analyses were used to assess factors independently associated with the rate of CDI. Results: 1,409 cases of HO-HCFA CDI were identified. CDI rates in 2002 were 13.9/10,000 person-days and decreased to 5.5/10,000 person-days by 2010. Multivariable regression analyses found that antibiotic (IRR = 18.79, 95% CI 14.09-25.07) and proton-pump inhibitor (PPI) or H2 blocker use (IRR = 7.71, 95% CI 5.47-10.86) were both independently associated with HO-HCFA CDI. Exposure to both medications demonstrated a synergistic risk (IRR = 37.55, 95% CI 28.39-49.67). Older age, Northeast region, and invasive respiratory procedure in the prior 30 days were also independent risk factors, while longer SCI duration and care at a SCI center were protective. Conclusion: Although decreasing, CDI rates in patients with SCI/D remain high. Targeted antimicrobial stewardship and pharmacy interventions that reduce antibiotic and PPI/H2 blocker use could have profound benefits in decreasing HO-HCFA CDI in this high-risk population.

Excess Length of Acute Inpatient Stay Attributable to Acquisition of Hospital-Onset Gram-Negative Bloodstream Infection with and without Antibiotic Resistance: A Multistate Model Analysis

Excess length of stay (LOS) is an important outcome when assessing the burden of nosocomial infection, but it can be subject to survival bias. We aimed to estimate the change in LOS attributable to hospital-onset (HO) Escherichia coli/Klebsiella spp. bacteremia using multistate models to circumvent survival bias. We analyzed a cohort of all patients with HO E.coli/Klebsiella spp. bacteremia and matched uninfected control patients within the U.S. Veterans Health Administration System in 2003–2013. A multistate model was used to estimate the change in LOS as an effect of the intermediate state (HO-bacteremia). We stratified analyses by susceptibilities to fluoroquinolones (fluoroquinolone susceptible (FQ-S)/fluoroquinolone resistant (FQ-R)) and extended-spectrum cephalosporins (ESC susceptible (ESC-S)/ESC resistant (ESC-R)). Among the 5964 patients with HO bacteremia analyzed, 957 (16.9%) and 1638 (28.9%) patients had organisms resistant to FQ and ESC, respectively. Any HO E.coli/Klebsiella bacteremia was associated with excess LOS, and both FQ-R and ESC-R were associated with a longer LOS than susceptible strains, but the additional burdens attributable to resistance were small compared to HO bacteremia itself (FQ-S: 12.13 days vs. FQ-R: 12.94 days, difference: 0.81 days (95% CI: 0.56–1.05), p < 0.001 and ESC-S: 11.57 days vs. ESC-R: 16.56 days, difference: 4.99 days (95% CI: 4.75–5.24), p < 0.001). Accurate measurements of excess attributable LOS associated with resistance can help support the business case for infection control interventions.

Trends in Health Care-Associated Infection Prevention Practices in US Veterans Affairs Hospitals From 2005 to 2017

IMPORTANCE

Health care-associated infection (HAI) is associated with substantial harm. To reduce HAI, the largest integrated health care system in the United States-the Veterans Health Administration-was an early adopter of infection prevention policies and initiatives. Whether these efforts translated into increased use of practices to prevent HAI in Veterans Affairs (VA) hospitals is unknown.

OBJECTIVE

To evaluate changes over time in infection prevention practices and the perception of the importance of infection prevention to hospital leadership.

DESIGN, SETTINGS, AND PARTICIPANTS

For this survey study, every 4 years between 2005 and 2017, infection preventionists were surveyed at all VA hospitals on use of practices associated with common HAIs, including central line-associated bloodstream infection (CLABSI), catheter-associated urinary tract infection (CAUTI), ventilator-associated pneumonia (VAP), and (beginning in 2013) Clostridioides difficile infection. Data analysis was performed from February 1, 2019, to July 1, 2019.

MAIN OUTCOMES AND MEASURES

Reported regular use of key infection prevention practices and perceived importance of infection prevention to hospital leadership.

RESULTS

Between 2005 and 2017, 320 total surveys were completed with response rates ranging from 59% (73 of 124) in 2017 to 80% (95 of 119) in 2005. Use of 12 different infection prevention practices increased. Since 2013, 92% (69 of 75) to 100% of VA hospitals reported regular use of key infection prevention practices for C difficile infection and CLABSI. In contrast, adoption of many practices to prevent CAUTI, although increasing, have lagged. Despite reported increases in the use of some practices for VAP such as semirecumbent positioning (89% [79 of 89] in 2005 vs 97% [61 of 63] in 2017, P = .007 for trend) and subglottic secretion drainage (23% [19 of 84] in 2005 vs 65% [40 of 62] in 2017, P < .001), use of other key practices such as daily interruptions of sedation (85% [55 of 65] in 2009 vs 87% [54 of 62] in 2017, P = .66) and early mobilization (81% [52 of 64] in 2013 vs 82% [51 of 62] in 2017, P = .88) has not increased. Antibiotic stewardship programs are now reported in nearly every VA hospital (97% [71 of 73]); however, some hospitals report practices for microbiologic testing for HAIs (eg, 22% [16 of 72] report routine urine culture testing in 2017) that could also contribute to antibiotic overuse.

CONCLUSIONS AND RELEVANCE

From 2005 to 2017, reported use of 12 different infection prevention practices increased in VA hospitals. Areas for continued improvement of infection prevention practices appear to include CAUTI, certain VAP practices, and diagnostic stewardship for HAI. The reported adoption of many infection prevention practices in VA hospitals was higher than in non-VA hospitals. As hospitals continue to merge and health systems become increasingly integrated, these successes could help inform patient safety broadly.

Contamination of health-care workers' hands with Escherichia coli and Klebsiella species after routine patient care: a prospective observational study

OBJECTIVE

To compare the frequency of health-care worker (HCW) hand contamination by Escherichia coli versus Klebsiella species after patient care and to determine activities associated with contamination.

METHODS

We conducted a prospective observational study at two tertiary-care centres. We observed HCWs caring for patients colonized/infected with E. coli or Klebsiella. HCW hands were cultured before room entry and after patient care. Contamination was defined as detecting E. coli or Klebsiella on HCW hands. Risk factors for contamination were analysed using logistic regression. Patient-to-HCW transmission was confirmed by pulsed-field gel electrophoresis (PFGE).

RESULTS

We performed 466 HCW observations: 290 from patients with E. coli, 149 with Klebsiella, and 27 with both species. Eighty-seven per cent of observations (404/464) occurred in patients who had received chlorhexidine bathing within 2 days. HCW hand contamination rates were similar between E. coli (6.2%; 18/290) and Klebsiella (7.4%; 11/149) (p 0.6). High-risk activities independently associated with contamination were toilet assistance (OR 9.34; 95% CI 3.10-28.16), contact with moist secretions (OR 6.93; 95% CI 2.82-17.00), and hygiene/bed-bathing (OR 3.80; 95% CI 1.48-9.80). PFGE identified identical/closely related isolates in the patient and HCW hands in 100% (18/18) of E. coli and 54.5% (6/11) of Klebsiella observations.

CONCLUSIONS

We did not find a difference in HCW hand contamination rates between E. coli and Klebsiella after patient care. Hand hygiene should be reinforced after high-risk activities. Discrepancies in matching patient and HCW hand isolates occurred more frequently for Klebsiella than for E. coli; differences in species-level transmission dynamics might exist.

Pathogenicity of Clinical OXA-48 Isolates and Impact of the OXA-48 IncL Plasmid on Virulence and Bacterial Fitness

OXA-48 is the most common carbapenemase in Enterobacterales in Germany and one of the most frequent carbapenemases worldwide. Several reports have associated bla_OXA–48 with a virulent host phenotype. To challenge this hypothesis, 35 OXA-48-producing clinical isolates of Escherichia coli (n = 15) and Klebsiella pneumoniae (n = 20) were studied in vitro, in vivo employing the Galleria mellonella infection model and by whole-genome sequencing. Clinical isolates belonged to 7 different sequence types (STs) in E. coli and 12 different STs in K. pneumoniae. In 26/35 isolates bla_OXA–48 was located on a 63 kb IncL plasmid. Horizontal gene transfer (HGT) to E. coli J53 was high in isolates with the 63 kb IncL plasmid (transconjugation frequency: ∼10³/donor) but low in isolates with non-IncL plasmids (<10^–6/donor). Several clinical isolates were both highly cytotoxic against human cells and virulent in vivo. However, 63 kb IncL transconjugants generated from these highly virulent isolates were not more cytotoxic or virulent when compared to the recipient strain. Additionally, no genes associated with virulence were detected by in silico analysis of OXA-48 plasmids. The 63 kb plasmid was highly stable and did not impair growth or fitness in E. coli J53. In conclusion, OXA-48 clinical isolates in Germany are diverse but typically harbor the same 63 kb IncL plasmid which has been reported worldwide. We demonstrate that this 63 kb IncL plasmid has a low fitness burden, high plasmid stability and can be transferred by highly efficient HGT which is likely the cause of the rapid dissemination of OXA-48 rather than the expansion of a single clone or gain of virulence.

Classification of bloodstream infections in patients recently discharged from acute-care facilities: Hospital acquired or healthcare-associated community onset?

Laboratory-identified bloodstream infections (LAB-ID BSIs) in recently discharged patients are likely to be classified as healthcare-associated community-onset (HCA-CO) infections, even though they may represent hospital-onset (HO) infections. A review of LAB-ID BSIs among patients discharged within 14 days revealed that 109 of 756 cases (14.4%) were HO infections. The BSI risk being misclassified as HCA CO may underestimate the hospital infection risk.

Trends in Collection of Microbiological Cultures Across Veterans Affairs Community Living Centers in the United States Over 8 Years

OBJECTIVES

To describe and evaluate changes in the collection of microbiological cultures across Veterans Affairs (VA) Community Living Centers (CLCs) nationally.

DESIGN

Descriptive study.

SETTING

146 VA CLCs.

PARTICIPANTS

We identified both positive and negative microbiological cultures collected during VA CLC admissions from January 2010 through December 2017.

MEASURES

We measured the average annual percentage change (AAPC) in the rate of cultures collected per 1000 bed days and per admission, overall and stratified by culture type (ie, urine, blood, skin and soft tissue, and respiratory tract). AAPCs were also calculated for the proportion and rate of positive cultures collected, overall and stratified by culture type and organism (ie, Escherichia coli, Proteus mirabilis, Staphylococcus aureus, Enterococcus spp, Pseudomonas aeruginosa, Klebsiella spp, Enterobacter spp, Morganella morganii, Citrobacter spp, Serratia marcescens, and Streptococcus pneumoniae). Joinpoint regression software was used to assess trends and estimate AAPCs and 95% confidence intervals (CIs).

RESULTS

Over 8 years, 355,329 cultures were collected. The rate of cultures collected per 1000 bed days of care decreased significantly by 6.0% per year (95% CI -8.7%, -3.2%). The proportion of positive cultures decreased by 0.9% (95% CI -1.4%, -0.4%). The most common culture types were urine (48.4%), followed by blood (27.7%). The rate of cultures collected per 1000 bed days of care decreased per year by 6.3% for urine, 5.0% for blood, 4.4% for skin and soft tissue, and 4.9% for respiratory tract. In 2010, S aureus was the most common organism identified, and in all subsequent years E coli was the most common.

CONCLUSION AND IMPLICATIONS

We identified a significant reduction in the number of cultures collected over time among VA CLCs. Our findings may be explained by decreases in the collection of unnecessary cultures in VA CLCs nationally due to increased antibiotic stewardship efforts targeting unnecessary culturing and antibiotic treatment.

Close proximity interactions support transmission of ESBL-K. pneumoniae but not ESBL-E. coli in healthcare settings

Antibiotic-resistance of hospital-acquired infections is a major public health issue. The worldwide emergence and diffusion of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, including Escherichia coli (ESBL-EC) and Klebsiella pneumoniae (ESBL-KP), is of particular concern. Preventing their nosocomial spread requires understanding their transmission. Using Close Proximity Interactions (CPIs), measured by wearable sensors, and weekly ESBL-EC-and ESBL-KP-carriage data, we traced their possible transmission paths among 329 patients in a 200-bed long-term care facility over 4 months. Based on phenotypically defined resistance profiles to 12 antibiotics only, new bacterial acquisitions were tracked. Extending a previously proposed statistical method, the CPI network's ability to support observed incident-colonization episodes of ESBL-EC and ESBL-KP was tested. Finally, mathematical modeling based on our findings assessed the effect of several infection-control measures. A potential infector was identified in the CPI network for 80% (16/20) of ESBL-KP acquisition episodes. The lengths of CPI paths between ESBL-KP incident cases and their potential infectors were shorter than predicted by chance (P = 0.02), indicating that CPI-network relationships were consistent with dissemination. Potential ESBL-EC infectors were identified for 54% (19/35) of the acquisitions, with longer-than-expected lengths of CPI paths. These contrasting results yielded differing impacts of infection control scenarios, with contact reduction interventions proving less effective for ESBL-EC than for ESBL-KP. These results highlight the widely variable transmission patterns among ESBL-producing Enterobacteriaceae species. CPI networks supported ESBL-KP, but not ESBL-EC spread. These outcomes could help design more specific surveillance and control strategies to prevent in-hospital Enterobacteriaceae dissemination.

Vital Signs: Trends in Staphylococcus aureus Infections in Veterans Affairs Medical Centers - United States, 2005-2017

Introduction

By 2007, all Department of Veterans Affairs medical centers (VAMCs) had initiated a multifaceted methicillin-resistant Staphylococcus aureus (MRSA) prevention program. MRSA and methicillin-susceptible S. aureus (MSSA) infection rates among VAMC inpatients from 2005 to 2017 were assessed.

Methods

Clinical microbiology data from any patient admitted to an acute-care VAMC in the United States from 2005 through 2017 and trends in hospital-acquired MRSA colonization were examined.

Results

S. aureus infections decreased by 43% overall during the study period (p<0.001), driven primarily by decreases in MRSA, which decreased by 55% (p<0.001), whereas MSSA decreased by 12% (p = 0.003). Hospital-onset MRSA and MSSA infections decreased by 66% (p<0.001) and 19% (p = 0.02), respectively. Community-onset MRSA infections decreased by 41% (p<0.001), whereas MSSA infections showed no significant decline. Acquisition of MRSA colonization decreased 78% during 2008–2017 (17% annually, p<0.001). MRSA infection rates declined more sharply among patients who had negative admission surveillance MRSA screening tests (annual 9.7% decline) compared with those among patients with positive admission MRSA screening tests (4.2%) (p<0.05).

Conclusions and Implications for Public Health Practice

Significant reductions in S. aureus infection following the VAMC intervention were led primarily by decreases in MRSA. Moreover, MRSA infection declines were much larger among patients not carrying MRSA at the time of admission than among those who were. Taken together, these results suggest that decreased MRSA transmission played a substantial role in reducing overall S. aureus infections at VAMCs. Recent calls to withdraw infection control interventions designed to prevent MRSA transmission might be premature and inadvisable, at least until more is known about effective control of bacterial pathogen transmission in health care settings. Effective S. aureus prevention strategies require a multifaceted approach that includes adherence to current CDC recommendations for preventing not only device- and procedure-associated infections, but also transmission of health care–prevalent strains.

Attributable Cost and Length of Stay Associated with Nosocomial Gram-Negative Bacterial Cultures

Few studies have estimated the excess inpatient costs due to nosocomial cultures of Gram-negative bacteria (GNB), and those that do are often subject to time-dependent bias. Our objective was to generate estimates of the attributable costs of the underlying infections associated with nosocomial cultures by using a unique inpatient cost data set from the U.S. Department of Veterans Affairs that allowed us to reduce time-dependent bias. Our study included data from inpatient admissions between 1 October 2007 and 30 November 2010. Nosocomial GNB-positive cultures were defined as clinical cultures positive for Acinetobacter, Pseudomonas, or Enterobacteriaceae between 48 h after admission and discharge. Positive cultures were further classified by site and level of resistance. We conducted analyses using both a conventional approach and an approach aimed at reducing the impact of time-dependent bias. In both instances, we used multivariable generalized linear models to compare the inpatient costs and length of stay for patients with and without a nosocomial GNB culture. Of the 404,652 patients included in the conventional analysis, 12,356 had a nosocomial GNB-positive culture. The excess costs of nosocomial GNB-positive cultures were significant, regardless of specific pathogen, site, or resistance level. Estimates generated using the conventional analysis approach were 32.0% to 131.2% greater than those generated using the approach to reduce time-dependent bias. These results are important because they underscore the large financial burden attributable to these infections and provide a baseline that can be used to assess the impact of improvements in infection control.

Trends over time in Escherichia coli bloodstream infections, urinary tract infections, and antibiotic susceptibilities in Oxfordshire, UK, 1998-2016: a study of electronic health records

BACKGROUND

Escherichia coli bloodstream infections are increasing in the UK and internationally. The evidence base to guide interventions against this major public health concern is small. We aimed to investigate possible drivers of changes in the incidence of E coli bloodstream infection and antibiotic susceptibilities in Oxfordshire, UK, over the past two decades, while stratifying for time since hospital exposure.

METHODS

In this observational study, we used all available data on E coli bloodstream infections and E coli urinary tract infections (UTIs) from one UK region (Oxfordshire) using anonymised linked microbiological data and hospital electronic health records from the Infections in Oxfordshire Research Database (IORD). We estimated the incidence of infections across a two decade period and the annual incidence rate ratio (aIRR) in 2016. We modelled the data using negative binomial regression on the basis of microbiological, clinical, and health-care-exposure risk factors. We investigated infection severity, 30-day all-cause mortality, and community and hospital amoxicillin plus clavulanic acid (co-amoxiclav) use to estimate changes in bacterial virulence and the effect of antimicrobial resistance on incidence.

FINDINGS

From Jan 1, 1998, to Dec 31, 2016, 5706 E coli bloodstream infections occurred in 5215 patients, and 228 376 E coli UTIs occurred in 137 075 patients. 1365 (24%) E coli bloodstream infections were nosocomial (onset >48 h after hospital admission), 1132 (20%) were quasi-nosocomial (≤30 days after discharge), 1346 (24%) were quasi-community (31-365 days after discharge), and 1863 (33%) were community (>365 days after hospital discharge). The overall incidence increased year on year (aIRR 1·06, 95% CI 1·05-1·06). In 2016, 212 (41%) of 515 E coli bloodstream infections and 3921 (28%) of 13 792 E coli UTIs were co-amoxiclav resistant. Increases in E coli bloodstream infections were driven by increases in community (aIRR 1·10, 95% CI 1·07-1·13; p<0·0001) and quasi-community (aIRR 1·08, 1·07-1·10; p<0·0001) cases. 30-day mortality associated with E coli bloodstream infection decreased over time in the nosocomial (adjusted rate ratio [RR] 0·98, 95% CI 0·96-1·00; p=0·03) group, and remained stable in the quasi-nosocomial (adjusted RR 0·98, 0·95-1·00; p=0·06), quasi-community (adjusted RR 0·99, 0·96-1·01; p=0·32), and community (adjusted RR 0·99, 0·96-1·01; p=0·21) groups. Mortality was, however, substantial at 14-25% across all hospital-exposure groups. Co-amoxiclav-resistant E coli bloodstream infections increased in all groups across the study period (by 11-18% per year, significantly faster than co-amoxiclav-susceptible E coli bloodstream infections; p_{heterogeneity}<0·0001), as did co-amoxiclav-resistant E coli UTIs (by 14-29% per year; p_{heterogeneity}<0·0001). Previous year co-amoxiclav use in primary-care facilities was associated with increased subsequent year community co-amoxiclav-resistant E coli UTIs (p=0·003).

INTERPRETATION

Increases in E coli bloodstream infections in Oxfordshire are primarily community associated, with substantial co-amoxiclav resistance; nevertheless, we found little or no change in mortality. Focusing interventions on primary care facilities, particularly those with high co-amoxiclav use, could be effective in reducing the incidence of co-amoxiclav-resistant E coli bloodstream infections, in this region and more generally.

FUNDING

National Institute for Health Research.

Impact of Implementing National Guidelines on Antibiotic Prescriptions for Acute Respiratory Tract Infections in Pediatric Emergency Departments: An Interrupted Time Series Analysis

Background

Many antibiotics are prescribed inappropriately in pediatric emergency departments (PEDs), but little data are available in these settings about effective interventions based on guidelines that follow the antimicrobial stewardship principle. Our aim was to assess the impact of implementing the 2011 national guidelines on antibiotic prescriptions for acute respiratory tract infection (ARTI) in PEDs.

Method

We conducted a multicentric, quasiexperimental, interrupted time series analysis of prospectively collected electronic data from 7 French PEDs. We included all pediatric patients who visited a participating PED during the study period from November 2009 to October 2014 and were diagnosed with an ARTI. The intervention consisted of local protocol implementation, education sessions, and feedback. The main outcome was the antibiotic prescription rate of discharge prescriptions for ARTI per 1000 PED visits before and after implementation, analyzed using the segmented regression model.

Results

We included 242534 patients with an ARTI. The intervention was associated with a significant change in slope for the antibiotic prescription rate per 1000 PED visits (-0.4% per 15-day period, P = .04), and the cumulative effect at the end of the study was estimated to be -30.9%, (95% CI [-45.2 to -20.1]), representing 13136 avoided antibiotic prescriptions. The broad-spectrum antibiotic prescription relative percentage decreased dramatically (-62.7%, 95% CI [-92.8; -32.7]) and was replaced by amoxicillin.

Conclusion

Implementation of the 2011 national French guidelines led to a significant decrease in the antibiotic prescription rate for ARTI and a dramatic drop in broad-spectrum antibiotic prescriptions, in favor of amoxicillin.

Antimicrobial Nonsusceptibility of Gram-Negative Bloodstream Isolates, Veterans Health Administration System, United States, 2003-20131

Bacteremia caused by gram-negative bacteria is associated with serious illness and death, and emergence of antimicrobial drug resistance in these bacteria is a major concern. Using national microbiology and patient data for 2003–2013 from the US Veterans Health Administration, we characterized nonsusceptibility trends of community-acquired, community-onset; healthcare-associated, community-onset; and hospital-onset bacteremia for selected gram-negative bacteria (Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, and Acinetobacter spp.). For 47,746 episodes of bacteremia, the incidence rate was 6.37 episodes/10,000 person-years for community-onset bacteremia and 4.53 episodes/10,000 patient-days for hospital-onset bacteremia. For Klebsiella spp., P. aeruginosa, and Acinetobacter spp., we observed a decreasing proportion of nonsusceptibility across nearly all antimicrobial drug classes for patients with healthcare exposure; trends for community-acquired, community-onset isolates were stable or increasing. The role of infection control and antimicrobial stewardship efforts in inpatient settings in the decrease in drug resistance rates for hospital-onset isolates needs to be determined.

Universal or targeted approach to prevent the transmission of extended-spectrum beta-lactamase-producing Enterobacteriaceae in intensive care units: a cost-effectiveness analysis

OBJECTIVE

Several control strategies have been used to limit the transmission of multidrug-resistant organisms in hospitals. However, their implementation is expensive and effectiveness of interventions for the control of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) spread is controversial. Here, we aim to assess the cost-effectiveness of hospital-based strategies to prevent ESBL-PE transmission and infections.

DESIGN

Cost-effectiveness analysis based on dynamic, stochastic transmission model over a 1-year time horizon.

PATIENTS AND SETTING

Patients hospitalised in a hypothetical 10-bed intensive care unit (ICU) in a high-income country.

INTERVENTIONS

Base case scenario compared with (1) universal strategies (eg, improvement of hand hygiene (HH) among healthcare workers, antibiotic stewardship), (2) targeted strategies (eg, screening of patient for ESBL-PE at ICU admission and contact precautions or cohorting of carriers) and (3) mixed strategies (eg, targeted approaches combined with antibiotic stewardship).

MAIN OUTCOMES AND MEASURES

Cases of ESBL-PE transmission, infections, cost of intervention, cost of infections, incremental cost per infection avoided.

RESULTS

In the base case scenario, 15 transmissions and five infections due to ESBL-PE occurred per 100 ICU admissions, representing a mean cost of €94 792. All control strategies improved health outcomes and reduced costs associated with ESBL-PE infections. The overall costs (cost of intervention and infections) were the lowest for HH compliance improvement from 55%/60% before/after contact with a patient to 80%/80%.

CONCLUSIONS

Improved compliance with HH was the most cost-saving strategy to prevent the transmission of ESBL-PE. Antibiotic stewardship was not cost-effective. However, adding antibiotic restriction strategy to HH or screening and cohorting strategies slightly improved their effectiveness and may be worthy of consideration by decision-makers.

A 17-Year Nationwide Study of Burkholderia cepacia Complex Bloodstream Infections Among Patients in the United States Veterans Health Administration

Background

Burkholderia cepacia complex (Bcc) are a group of multidrug-resistant gram-negative bacteria rarely reported in patients without cystic fibrosis (CF) or immunocompromising conditions. We investigated Bcc bloodstream infections (BSIs) in a cohort of non-CF patients from the US Veterans Health Administration (VHA).

Methods

Using VHA databases, we identified patients with Bcc BSI at facilities nationwide from 1999 through 2015. We ascertained clinical characteristics, treatments, and outcomes and identified factors associated with 30-day mortality in logistic regression analysis.

Results

We identified 248 patients with Bcc BSI, who were of advanced age (mean, 68 years), chronically ill, and had severe disease. The most common sources were central venous catheters (41%) and pneumonia (20%). Most cases were hospital-acquired (155 [62%]) or healthcare-associated (70 [28%]). Mortality at 14, 30, and 90 days was 16%, 25%, and 36%, respectively. Trimethoprim-sulfamethoxazole (TMP-SMX) and fluoroquinolones were active against 94% and 88% of isolates, respectively. Susceptibility to ceftazidime and meropenem occurred in approximately 70% of the isolates. The most prescribed antibiotics were fluoroquinolones (35%), followed by carbapenems (20%), TMP-SMX (18.5%), and ceftazidime (11%). In regression analysis, age (OR, 1.06 [95% confidence interval {CI}, 1.02-1.10], per added year) and the Pitt bacteremia score (OR, 1.65 [95% CI, 1.44-1.94], per unit increase) were associated with higher 30-day mortality.

Conclusions

In this large cohort of BSIs caused by Bcc, cases were mostly hospital-acquired and we observed high mortality, significant resistance to ceftazidime, and limited use of TMP-SMX. These observations add to our understanding of Bcc infection in non-CF patients and highlight the need for interventions to improve their outcome.

Infection control interventions affected by resource shortages: impact on the incidence of bacteremias caused by carbapenem-resistant pathogens

We evaluated an infection control (IC) program influenced by personnel and material resource shortages on the incidence of bloodstream infections (BSI) due to carbapenem-resistant Klebsiella pneumoniae (CRKP), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CRPA) in an endemic region. Between January 2010 and December 2015, all BSI episodes caused by CRKP, CRAB, and CRPA were recorded. An IC bundle was implemented in January 2012. We evaluated the effect of the interventions on BSI rates between the pre-intervention (2010-2011) and intervention (2012-2013) periods, using an interrupted time-series model. From 2014, when interventions were still applied, BSI incidence was gradually increased. For this reason, we evaluated with a linear mixed effects model several factors possibly contributing to this increase for the years 2012-2015, which was considered as the intervention/follow-up period. During the study period, 351 patients with BSI were recorded, with a total of 538 episodes; the majority (83.6%) occurred in the intensive care unit (ICU). The BSI incidence rate per year during 2010-2015 for ICU patients was 21.03/19.63/17.32/14.45/22.85/25.02 per 1000 patient-days, respectively, with the reduction in BSI levels after the start of intervention marginal (p = 0.054). During the follow-up period (2014-2015), the most influential factors for the increased BSI incidence were the reduced participation in educational courses and compliance with hand hygiene. The implementation of IC interventions reduced the BSI incidence rates, particularly for ICU patients. However, factors possibly related to the restrictions of human and material resources apparently contributed to the observed expansion of BSI in our endemic setting.

Eight years of decreased methicillin-resistant Staphylococcus aureus health care-associated infections associated with a Veterans Affairs prevention initiative

BACKGROUND

Declines in methicillin-resistant Staphylococcus aureus (MRSA) health care associated infections (HAIs) were previously reported in Veterans Affairs acute care (2012), spinal cord injury (SCIU) (2011), and long-term-care facilities (LTCFs) (2012). Here we report continuing declines in infection rates in these settings through September 2015.

METHODS

Monthly data entered into a national database from 127 acute care facilities, 22 SCIUs, and 133 LTCFs were evaluated for trends using negative binomial regression.

RESULTS

There were 23,153,240 intensive care unit (ICU) and non-ICU, and 1,794,234 SCIU patient-days from October 2007-September 2015, and 22,262,605 LTCF resident-days from July 2009-September 2015. Admission nasal swabbing remained >92% in all 3 venues. Admission prevalence changed from 13.2%-13.5% in acute care, from 35.1%-32.0% in SCIUs, and from 23.1%-25.0% in LTCFs during the analysis periods. Monthly HAI rates fell 87.0% in ICUs, 80.1% in non-ICUs, 80.9% in SCIUs, and 49.4% in LTCFs (all P values < .0001 for trend). During September 2015, there were 2 MRSA HAIs reported in ICUs, 20 (with 3 in SCIUs) in non-ICUs, and 31 in LTCFs nationwide.

CONCLUSIONS

MRSA HAI rates declined significantly in acute care, SCIUs, and LTCFs over 8 years of the Veterans Affairs MRSA Prevention Initiative.