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

Impact of discontinuation of contact precautions on surveillance- and whole genome sequencing-defined methicillin-resistant Staphylococcus aureus healthcare-associated infections

Objective

Prior studies evaluating the impact of discontinuation of contact precautions (DcCP) on methicillin-resistant Staphylococcus aureus (MRSA) outcomes have characterized all healthcare-associated infections (HAIs) rather than those likely preventable by contact precautions. We aimed to analyze the impact of DcCP on the rate of MRSA HAI including transmission events identified through whole genome sequencing (WGS) surveillance.

Design

Quasi experimental interrupted time series.

Setting

Acute care medical center.

Participants

Inpatients.

Methods

The effect of DcCP (use of gowns and gloves) for encounters among patients with MRSA carriage was evaluated using time series analysis of MRSA HAI rates from January 2019 through December 2022, compared to WGS-defined attributable transmission events before and after DcCP in December 2020.

Results

The MRSA HAI rate was 4.22/10,000 patient days before and 2.98/10,000 patient days after DcCP (incidence rate ratio [IRR] 0.71 [95% confidence interval 0.56-0.89]) with a significant immediate decrease (P = .001). There were 7 WGS-defined attributable transmission events before and 11 events after DcCP (incident rate ratio 0.90 [95% confidence interval 0.30-2.55]).

Conclusions

DcCP did not result in an increase in MRSA HAI or, in WGS-defined attributable transmission events. Comprehensive analyses of the effect of transmission prevention measures should include outcomes specifically measuring transmission-associated HAI.

Active Surveillance and Contact Precautions for Preventing Methicillin-Resistant Staphylococcus aureus Healthcare-Associated Infections During the COVID-19 Pandemic

BACKGROUND

Statistically significant decreases in methicillin-resistant Staphylococcus aureus (MRSA) healthcare-associated infections (HAIs) occurred in Veterans Affairs (VA) hospitals from 2007 to 2019 using a national policy of active surveillance (AS) for facility admissions and contact precautions for MRSA colonized (CPC) or infected (CPI) patients, but the impact of suspending these measures to free up laboratory resources for testing and conserve personal protective equipment for coronavirus disease 2019 (COVID-19) on MRSA HAI rates is not known.

METHODS

From July 2020 to June 2022 all 123 acute care VA hospitals nationwide were given the rolling option to suspend (or re-initiate) any combination of AS, CPC, or CPI each month, and MRSA HAIs in intensive care units (ICUs) and non-ICUs were tracked.

RESULTS

There were 917 591 admissions, 5 225 174 patient-days, and 568 MRSA HAIs. The MRSA HAI rate/1000 patient-days in ICUs was 0.20 (95% confidence interval [CI], .15-.26) for facilities practicing "AS + CPC + CPI" compared to 0.65 (95% CI, .41-.98; P < .001) for those not practicing any of these strategies, and in non-ICUs was 0.07 (95% CI, .05-.08) and 0.12 (95% CI, .08-.19; P = .01) for the respective policies. Accounting for monthly COVID-19 facility admissions using a negative binomial regression model did not change the relationships between facility policy and MRSA HAI rates. There was no significant difference in monthly facility urinary catheter-associated infection rates, a non-equivalent dependent variable, in the policy categories in either ICUs or non-ICUs.

CONCLUSIONS

Facility removal of MRSA prevention practices was associated with higher rates of MRSA HAIs in ICUs and non-ICUs.

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.

Success and failures in MRSA infection control during the COVID-19 pandemic

Private sector facilities in the United States have experienced a resurgence of Methicillin-resistant Staphylococcus aureus (MRSA) hospital-onset infections during the COVID-19 pandemic, which eliminated all gains that were achieved over the last decade. The third quarter of 2021, the Standardized Infection Ratio for hospital onset MRSA bloodstream infections was 1.17, well above the baseline value of 1.0. In contrast, the Veterans Health Administration (VHA) has been able to maintain its mitigation efforts and low rates of MRSA hospital-onset infections through the second quarter of fiscal year 2022 (Mar. 31, 2022), the most recent available data. The difference may be explained not only by the VHA’s use of uniform mitigating policies which rely on active surveillance and contact precautions, but also on the VAH’s ability to maintain adequate staffing during the pandemic. Future research into MRSA mitigation is warranted and this data supports the need for healthcare system transformation.

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.

Establishment of an antimicrobial stewardship strategy on the surgical NICU at Cairo University specialized pediatric hospital

PURPOSE

Antimicrobial resistance is a major concern that we are facing nowadays. This is due to antibiotic misuse and bacteria developing resistance to the commonly used antibiotics. This may lead to increased mortality and consumption of country resources. Implementation of an antimicrobial stewardship program [ASP] can limit the use of unnecessary antibiotics and subsequently decrease the infection rates with better patient outcome. We aimed to control antibiotic misuse, reduce infection rate, decrease drug costs, and reduce length of hospital stay in the ICU.

METHODS

We conducted a prospective study on the surgical neonatal ICU [SNICU] over a period of 6 months divided into pre-implementation phase, followed by an ASP phase, in which we applied the antibiotic guidelines approved by the ASP committee. Data were collected in the two phases and analyzed for demographics, compliance with guidelines, prescribed antibiotics, lab investigations, surgical site infection [SSI], length of stay and patient outcome.

RESULTS

Compliance to the guidelines was encountered in 86% and SSI rate decreased to 20%. Days of Therapy (DOT) per 1000 patient days showed a significant decrease in Ampicillin Sulbactam by 296 (p = 0.024), Imipenem by 220.34 (p = 0.024) and Vancomycin by 287.34 (p = 0.048). Drug cost showed a 1185.97 EGP decrease in the ASP period compared to the pre-implementation period (p = 0.714). Average LOS decreased in the ASP period by a mean difference of 2.5 (p = 0.027).

CONCLUSION

ASP implementation can control antibiotic misuse, decrease the medical care expenses and improve patient outcome.

TYPE OF STUDY

Clinical research paper.

LEVEL OF EVIDENCE

Level one.

Characterization of MRSA in Canada from 2007 to 2016

OBJECTIVES

This study assessed the demographic and molecular characteristics of community-associated (CA) and healthcare-associated (HA) MRSA genotypes in Canadian hospitals between 2007 and 2016.

METHODS

A total of 1963 MRSA were identified among 9103 Staphylococcus aureus isolates collected from inpatients and outpatients presenting to tertiary-care medical centres across Canada. Antimicrobial susceptibility testing was performed by broth microdilution in accordance with CLSI standards (M7 11th edition, 2018). PCR was performed to detect the Panton-Valentine leucocidin (PVL) genes and molecular analysis was performed by spa typing.

RESULTS

Between 2007 and 2016, the annual proportion of S. aureus that were MRSA decreased from 26.1% to 16.9% (P < 0.0001). The proportion of CA-MRSA genotypes increased significantly from 20.8% in 2007 to 56.3% in 2016 (P < 0.0001) while HA-MRSA genotypes decreased from 79.2% to 43.8% throughout the study period (P < 0.0001). Predominant genotypes included HA genotype CMRSA2 (USA100/800) (53.6%) and CA genotype CMRSA10 (USA300) (24.9%). PVL was present in 30.1% of all MRSA isolates, including 78.4% of CA-MRSA and 1.7% of HA-MRSA genotypes. Resistance to clarithromycin, clindamycin, trimethoprim/sulfamethoxazole and fluoroquinolones decreased significantly over time (P < 0.0001).

CONCLUSIONS

The proportion of MRSA in Canada declined between 2007 and 2016. In contrast, the proportion of CA-MRSA strain types, particularly CMRSA10 (USA300), continues to increase. In 2016, CA-MRSA genotypes surpassed HA-MRSA as the most common cause of MRSA infections in Canadian hospitals.

One Health in hospitals: how understanding the dynamics of people, animals, and the hospital built-environment can be used to better inform interventions for antimicrobial-resistant gram-positive infections

Despite improvements in hospital infection prevention and control, healthcare associated infections (HAIs) remain a challenge with significant patient morbidity, mortality, and cost for the healthcare system. In this review, we use a One Health framework (human, animal, and environmental health) to explain the epidemiology, demonstrate key knowledge gaps in infection prevention policy, and explore improvements to control Gram-positive pathogens in the healthcare environment. We discuss patient and healthcare worker interactions with the hospital environment that can lead to transmission of the most common Gram-positive hospital pathogens – methicillin-resistant Staphylococcus aureus, Clostridioides (Clostridium) difficile, and vancomycin-resistant Enterococcus – and detail interventions that target these two One Health domains. We discuss the role of animals in the healthcare settings, knowledge gaps regarding their role in pathogen transmission, and the absence of infection risk mitigation strategies targeting animals. We advocate for novel infection prevention and control programs, founded on the pillars of One Health, to reduce Gram-positive hospital-associated pathogen transmission.

Methicillin-resistant Staphylococcus aureus Colonization and Pre- and Post-hospital Discharge Infection Risk

Background

The Department of Veterans Affairs implemented an active surveillance program for methicillin-resistant Staphylococcus aureus (MRSA) in 2007 in which acute care inpatients are tested for MRSA carriage on admission, unit-to-unit transfer, and discharge. Using these data, we followed patients longitudinally to estimate the difference in infection rates for those who were not colonized, those who were colonized on admission (importers), and those who acquired MRSA during their stay. We examined MRSA infections that occurred prior to discharge and at 30, 90, 180, and 365 days after discharge.

Methods

We constructed a dataset of 985626 first admissions from January 2008 through December 2015 who had surveillance tests performed for MRSA carriage. We performed multivariable Cox proportional hazards and logistic regression models to examine the relationship between MRSA colonization status and infection.

Results

The MRSA infection rate across the predischarge and 180-day postdischarge time period was 5.5% in importers and 7.0% in acquirers without a direct admission to the intensive care unit (ICU) and 11.4% in importers and 11.7% in acquirers who were admitted directly to the ICU. The predischarge hazard ratio for MRSA infection was 29.6 (95% confidence interval [CI], 26.5-32.9) for importers and 28.8 (95% CI, 23.5-35.3) for acquirers compared to those not colonized. Fully 63.9% of all MRSA pre- and postdischarge infections among importers and 61.2% among acquirers occurred within 180 days after discharge.

Conclusions

MRSA colonization significantly increases the risk of subsequent MRSA infection. In addition, a substantial proportion of MRSA infections occur after discharge from the hospital.

A targeted assessment for prevention strategy to decrease Clostridioides difficile infections in Veterans Affairs acute-care medical centers

OBJECTIVE

A guideline for the prevention of Clostridioides difficile infection (CDI) in 127 Veterans Health Administration acute-care facilities was implemented in July 2012. Beginning in 2015, a targeted assessment for prevention strategy was used to evaluate facilities for hospital-onset healthcare-facility-associated CDIs to focus prevention efforts where they might have the most impact in reaching a reduction goal of 30% nationwide.

METHODS

We calculated standardized infection ratios (SIRs) and cumulative attributable differences (CADs) using a national data baseline. Facilities were ranked by CAD, and those with the 10 highest CAD values were targeted for periodic conference calls or a site visit from January 2016-September 2019.

RESULTS

The hospital-onset healthcare-facility-associated CDI rate in the 10 facilities with the highest CADs declined 56% during the process improvement period, compared to a 44% decline in the 117 nonintervention facilities (P = .03).

CONCLUSION

Process improvement interventions targeting facilities ranked by CAD values may be an efficient strategy for decreasing CDI rates in a large healthcare system.

Trends in antimicrobial resistance of bacterial pathogens in Harare, Zimbabwe, 2012-2017: a secondary dataset analysis

BACKGROUND

Antimicrobial resistance is one of the most serious public health threats of the twenty-first century. The implementation of AMR surveillance in Zimbabwe is limited. However, data from a private laboratory in Harare revealed increasing resistance rates to common antibiotics like ampicillin (i.e., from 73.9% in 2011 to 74.6% in 2015). The increasing resistance rates indicate that Zimbabwe is affected by AMR. This study was done to determine the magnitude of AMR in Harare and determine the trends of AMR to first-line and to last-resort antibiotics and make recommendations to mitigate the problem.

METHODS

A retrospective record review of data collected from the microbiology department at a private laboratory between January 2012 and December 2017 was done. The outcome of interest was the antibiotic susceptibility of bacterial isolates. Microsoft Excel 2016 was used to plot trends from 2012 to 2017 and Epi Info™7 was used for statistical analysis.

RESULTS

A total of 23,432 isolates, of 12 medically important bacteria were analysed. Forty-three percent of the isolates were from urines, 36.7% were from pus swabs and 7% were from blood. The most common pathogen was Escherichia coli (43.2%), followed by Staphylococcus aureus (15.8%) and the least common was Neisseria gonorrhoea (0.2%). Resistance was highest to ampicillin followed by penicillin, both ranging between 70 and 100% over the six years. Statistically significant increases in resistance to commonly used antibiotics were observed in amoxicillin-resistant E. coli and Streptococcus pneumonia and third generation cephalosporin-resistant E. coli. There was an increase in resistance to last-line antibiotics i.e., fluoroquinolone-resistant Salmonella spp. and carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter baumannii. However, methicillin-resistant S. aureus showed a decreasing trend.

CONCLUSIONS

There is a high burden of drug resistance to common antibiotics in Harare and an emergence of resistance to last-line antibiotics.

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.

A Longitudinal Study of S. aureus Infection in a National Cohort of Surgical Patients

BACKGROUND

Postoperative infections are a common and often preventable complication of surgery. S. aureus is a prevalent organism cultured in these infections and is associated with morbidity, mortality, and increased healthcare utilization. However, the long-term burden of S. aureus infection in surgical patients is not well studied. The purpose of this retrospective observational study is to assess the incidence, time trend, and burden of S. aureus infection up to 1 year after surgery.

METHODS

We obtained manually-reviewed data from the VA Surgical Quality Improvement Program (VASQIP) to identify surgeries in all major specialties. These were combined with laboratory microbiology and pharmacy data to identify pneumonia and infections of the urinary tract, surgical site, and blood.

RESULTS

In the study population of 559,550 patients, S. aureus incidence decreased each year, from 2.1% in 2008 to 1.1% in 2015. Among these, incidence of methicillin-resistant S. aureus (MRSA) infection decreased from 0.7% to 0.4%, and methicillin-susceptible S. aureus (MSSA) decreased from 1.4% to 0.7%. S. aureus infection was associated with increased length of stay, ED utilization, inpatient admissions, as well as a 4-fold increase in mortality.

CONCLUSIONS

This is one of the largest studies describing the long-term incidence of S. aureus in the surgical population of a national integrated healthcare system. We conclude that the burden of S. aureus infection extends well beyond the conventional 30-day postoperative window, and late infection should be included in assessing the effects of interventions.

Shifting trends and age distribution of ESKAPEEc resistance in bloodstream infection, Southwest China, 2012-2017

Background

ESKAPEEc contribute to a majority of bloodstream infections (BSIs) and their antibiogram have changed overtime, while data concerning about these alterations are lacking in China. Added that a paucity of studies referred to ESKAPEEc in pediatric BSIs, our study aimed to demonstrate the longitudinal alterations of ESKAPEEc distribution and antibiogram in adult and pediatric BSIs in Southwest China.

Methods

A multicenter retrospective surveillance study was launched from 2012 to 2017. Data of China Antimicrobial Resistance Surveillance System (CARSS) was analyzed by Whonet 5.6 and Graphpad Prism 6 Software. Chi-square test or Fisher’s exact test was used to examine and compare temporal changes.

Results

A total of 32,259 strains was isolated, with 17.4% from pediatric BSIs. ESKAPEEc contributed to 58.67% (18,924/32,259) of BSIs, with 65.3% of adult BSIs and 27.2% of pediatric BSIs. Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) were the two predominant species. Carbapenem resistance was prevalent in 0.76, 4.60, 9.47,13.66, 59.47% of E. coli, K. pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa (P. aeruginosa) and Acinetobacter baumannii (A. baumannii), respectively. The proportions of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VREFM) were 28.91% and 2.20%, respectively. Between 2012-2014 and 2015–2017, E. coli and K. pneumonia showed significantly increased resistance rates to imipenem but decreased to ceftriaxone and ceftazidime, while A. baumannii exhibited reduced resistances to almost all the beta-lactams tested. The prevalence of antimicrobial resistance to most of agents against Gram-positive ESKAPEEc did not significantly varied during the same timeframe. In comparison with those from adult BSIs, K. pneumoniae from pediatric BSIs exhibited high resistance rates to all the beta-lactams tested, especially to carbapenems (12.79% vs 3.87%), while A. baumannii showed low resistance rates to all the agents.

Conclusions

Ongoing burden of ESKAPEEc in BSIs and increasing trend of imipenem resistance in E. coli and K. pneumoniae call for continued surveillance. Carbapenems are still active against Gram-negative ESKAPEEc, except for A. baumannii and vancomycin or linezolid is still effective against Gram-positive ESKAPEEc. Carbapenem-resistant K. pneumoniae in children and carbapenem-resistant A. baumannii in adults necessitate effective antimicrobial strategies in consideration of age stratification.

Rapid Detection of Methicillin-Resistant Staphylococcus aureus in BAL: A Pilot Randomized Controlled Trial

BACKGROUND

Guidelines recommend empirical vancomycin or linezolid for patients with suspected pneumonia at risk for methicillin-resistant Staphylococcus aureus (MRSA). Unneeded vancomycin or linezolid use may unnecessarily alter host flora and expose patients to toxicity. We therefore sought to determine if rapid testing for MRSA in BAL can safely decrease use of vancomycin or linezolid for suspected MRSA pneumonia.

METHODS

Operating characteristics of the assay were initially validated against culture on residual BAL. A prospective, unblinded, randomized clinical trial to assess the effect of antibiotic management made on the basis of rapid diagnostic testing (RDT) compared with usual care was subsequently conducted, with primary outcome of duration of vancomycin or linezolid administration. Secondary end points focused on safety.

RESULTS

Sensitivity of RPCR was 95.7%, with a negative likelihood ratio of 0.04 for MRSA. The clinical trial randomized 45 patients: 22 to antibiotic management made on the basis of RDT and 23 to usual care. Duration of vancomycin or linezolid administration was significantly reduced in the intervention group (32 h [interquartile range, 22-48] vs 72 h [interquartile range, 50-113], P < .001). Proportions with complications and length of stay trended lower in the intervention group. Hospital mortality was 13.6% in the intervention group and 39.1% for usual care (95% CI of difference, -3.3 to 50.3, P = .06). Standardized mortality ratio was 0.48 for the intervention group and 1.18 for usual care.

CONCLUSIONS

A highly sensitive BAL RDT for MRSA significantly reduced use of vancomycin and linezolid in ventilated patients with suspected pneumonia. Management made on the basis of RDT had no adverse effects, with a trend to lower hospital mortality.

TRIAL REGISTRY

ClinicalTrials.gov; No. NCT02660554; URL: www.clinicaltrials.gov.

Reassessing the need for active surveillance of extended-spectrum beta-lactamase-producing Enterobacteriaceae in the neonatal intensive care population

OBJECTIVE

To determine the continued need for active surveillance to prevent extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) transmission in a neonatal intensive care unit (NICU).

DESIGN

This retrospective observational study included patients with ESBL-E colonization or infection identified during their NICU stay at our institution between 1999 and March 2018. Active surveillance was conducted between 1999 and March 2017 by testing rectal swab specimens collected upon admission and weekly thereafter. The overall incidence rates, of ESBL-E colonization or infection (including hospital acquired) before and after active surveillance were calculated. The cost associated with active surveillance was then estimated.

RESULTS

Overall, 171 NICU patients were found to have ESBL-E colonization or infection, and 150 of those patients (87.7%) were detected by active surveillance. The overall incidence rate was 1.4 per 100 patient admissions. The hospital-acquired incidence rate was 0.41 per 1,000 patient days, and this rate had decreased since 2002, with an average of 6 cases detected annually. A significant decrease was observed in 2009 when the unit moved to a new single-bed unit featuring private rooms. Active surveillance was discontinued with no increase in the number of infections. Of the 150 ESBL-E colonized patients, 14 (9.3%) subsequently developed an infection. Active surveillance resulted in a total of 50,950 specimen collections and a cost of $127,187 for processing, an average of $848 to detect 1 ESBL-E colonized patient.

CONCLUSION

ESBL-E transmission and infection in our NICU remains uncommon. Active surveillance may have contributed to the decline of ESBL-E transmission when used in conjunction with contact precautions and private rooms, but its relatively high cost could be prohibitive.

Genetic shifts in methicillin-resistant Staphylococcus aureus epidemic clones and toxin gene profiles in Japan: comparative analysis among pre-epidemic, epidemic and post-epidemic phases

PURPOSE

The decline in methicillin-resistant Staphylococcus aureus (MRSA) isolation rates has become a general observation worldwide, including Japan. We hypothesized that some genetic shift in MRSA might cause this phenomenon, and therefore we investigated the genetic profiles among MRSA clinical isolates obtained from three different epidemic phases in Japan.

METHODOLOGY

A total of 353 MRSA isolates were selected from 202 medical facilities in 1990 (pre-epidemic phase), 2004 (epidemic phase) and 2016 (post-epidemic phase). Molecular typing was performed by PCR detection of 22 genes using the polymerase chain reaction (PCR)-based ORF typing (POT) system, including an additional eight genes including small genomic islets and seven toxin genes.

RESULTS

Isolates with a POT1 of score 93, identified as presumed clonal complex (pCC)5-staphylococcal cassette chromosome mec (SCCmec) type II including ST5-SCCmec type II New York/Japan clone, represented the major epidemic MRSA lineage in 1990 and 2004. In 2016, however, a marked decrease in isolates with a POT1 score of 93, along with changes in the epidemiology of toxin genes carried, was noted, where the carriers of tst genes including the tst-sec combination were markedly reduced, and those possessing the seb gene alone were markedly increased. Rather, isolates with a POT1 score of 106, including pCC1 or pCC8 among the isolates with SCCmec type IV, which often links to community-associated MRSA, were predominant. Interestingly, the pCC1 and pCC8 lineages were related to sea and tst-sec carriage, respectively.

CONCLUSIONS

Over time, a transition in MRSA genetic profiles from a POT1 score of 93 in 1990 and 2004 to 106 in 2014 was found in Japan.

Trends in Community Versus Health Care-Acquired Methicillin-Resistant Staphylococcus aureus Infections

Since the first clinical isolate of methicillin-resistant Staphylococcus aureus was described in 1961, this pathogen has established itself as a leading cause of health care-associated infections. More recently, MRSA has become a relatively common cause of infection among persons without typical health care-associated risk factors and is now the most common cause of community-onset purulent skin and soft-tissue infections in many regions of the USA. The appearance of "community-associated" MRSA is not due to the expansion of health care-associated MRSA into the community but rather the result of the independent emergence of a novel clone of MRSA. There are some encouraging data to suggest that the incidence of MRSA infection, particularly invasive infections, is decreasing in the USA, but this pathogen remains a common cause of infection associated with substantial morbidity and mortality. Thus, there is ongoing need for effective and safe prevention, diagnosis, and treatment strategies.

Active identification of patients who are methicillin-resistant Staphylococcus aureus colonized is not associated with longer duration of vancomycin therapy

BACKGROUND

Excessive prescribing of vancomycin among patients admitted to inpatient wards is a challenge for antimicrobial stewardship programs, especially in the setting of expanded screening programs for methicillin-resistant Staphylococcus aureus (MRSA). Studies examining factors associated with longer duration of vancomycin use are limited.

METHODS

We conducted a retrospective cohort study to assess the impact of universal MRSA admission screening on duration of vancomycin use at the VA Boston Healthcare System during the period from January 2013-November 2015.

RESULTS

A total of 2,910 patients were administered intravenous vancomycin during the study period. A clinical culture positive for MRSA was strongly associated with vancomycin administration lasting >72 hours (odds ratio [OR], 2.72; 95% confidence interval [CI], 1.86-3.97; P < .001). After controlling for clinical culture results, admission MRSA colonization was not associated with vancomycin use past 72 hours (OR, 0.94; 95% CI, 0.8-1.1). A negative MRSA nasal swab on admission had a high negative predictive value for all MRSA infections evaluated (99.6% for pneumonia, 99.6% for bloodstream infection, and 98.1% for skin and soft tissue infection).

CONCLUSIONS

Admission surveillance for MRSA nasal colonization is not a major driver of prolonged vancomycin use. A negative admission MRSA nasal screen may be a useful tool for antimicrobial stewardship programs to limit vancomycin use, particularly in noncritically ill patients.

Preventing Transmission of Multidrug-Resistant Pathogens in the Intensive Care Unit

Infection control in the intensive care unit (ICU) has seen many advances, including rapid molecular screening tests for resistant organisms and chlorhexidine use in daily baths. Although these developments advance the cause of infection prevention, compliance with some of the basic measures remains elusive. Hand hygiene, antimicrobial stewardship, and reduction in device use remain the low-technology interventions that could have a major impact on nosocomial transmission of antimicrobial-resistant organisms. Although continued research is needed on new and old ways of preventing nosocomial infections, ICU staff must persevere in improving adherence with the measures that are known to be effective.

The incidence of MRSA infections in the United States: is a more comprehensive tracking system needed?

A review of epidemiological studies on the incidence of MRSA infections overtime was performed along with an analysis of data available for download from Hospital Compare (https://data.medicare.gov/data/hospital-compare). We found the estimations of the incidence of MRSA infections varied widely depending upon the type of population studied, the types of infections captured and in the definitions and terminology used to describe the results. We could not find definitive evidence that the incidence of MRSA infections in U.S. community or facilities is decreasing significantly. Of concern are recent data reported to the National Healthcare Safety Network (NHSN) on MRSA bloodstream infections which indicate that by the end of 2015 there had been little change in the average facility Standardized Infection Ratio (0.988), compared to a 2010-2011 baseline and is significantly increased compared to the previous year. This is in contradistinction to the recent Veterans Administration study which reported over an 80% reduction in MRSA infections. However, this discrepancy may be due to the inability to reconcile the baselines of the two data sets; and the observed increase may be artifactual due to aberrations in the NHSN tracking system. Our review supports the need for implementation of a comprehensive tracking and monitoring system involving all types of healthcare facilities for multi-drug resistant organisms, along with concomitant funding for both staff and infrastructure. Without such a system, determining the effectiveness of interventions such as antibiotic stewardship and chlorhexidine bathing will be hindered.