Carbapenem-resistant Enterobacterales (CRE) are a growing public health concern due to resistance to multiple antibiotics and potential to cause health care-associated infections with high mortality. Carbapenemase-producing CRE are of particular concern given that carbapenemase-encoding genes often are located on mobile genetic elements that may spread between different organisms and species. In this study, we performed phenotypic and genotypic characterization of CRE collected at eight U.S. sites participating in active population- and laboratory-based surveillance of carbapenem-resistant organisms. Among 421 CRE tested, the majority were isolated from urine (n = 349, 83%). Klebsiella pneumoniae was the most common organism (n = 265, 63%), followed by Enterobacter cloacae complex (n = 77, 18%) and Escherichia coli (n = 50, 12%). Of 419 isolates analyzed by whole genome sequencing, 307 (73%) harbored a carbapenemase gene; variants of bla(KPC) predominated (n = 299, 97%). The occurrence of carbapenemase-producing K. pneumoniae, E. cloacae complex, and E. coli varied by region; the predominant sequence type within each genus was ST258, ST171, and ST131, respectively. None of the carbapenemase-producing CRE isolates displayed resistance to all antimicrobials tested; susceptibility to amikacin and tigecycline was generally retained.

Background: Detection of carbapenem-resistant Pseudomonas aeruginosa (CRPA) with carbapenamase-producing (CP) genes is critical for preventing transmission. Our objective was to assess whether certain antimicrobial susceptibility testing (AST) profiles can efficiently identify CP-CRPA.Methods: We defined CRPA as P. aeruginosa with imipenem or meropenem MICs of ≥8μg/ml; CP-CRPA were CRPA with CP genes (bla (KPC)/bla (IMP)/bla (NDM)/bla (VIM)). We assessed the sensitivity and specificity of AST profiles to detect CP-CRPA among CRPA collected by CDC's Antibiotic Resistance Laboratory Network (AR Lab Network) and the Emerging Infections Program (EIP) during 2017-2019.Results: Three percent (195/6192) of AR Lab Network CRPA were CP-CRPA. Among CRPA, adding not susceptible (NS) to cefepime or ceftazidime to the definition had 91% sensitivity and 50% specificity for identifying CP-CRPA; NS to ceftolozane-tazobactam had 100% sensitivity and 86% specificity. Of 965 EIP CRPA evaluated for CP genes, seven CP-CRPA were identified; 6 of 7 were NS to cefepime and ceftazidime, and all 7 were NS to ceftolozane-tazobactam. Among 4182 EIP isolates, clinical laboratory AST results were available for 96% for cefepime, 80% for ceftazidime, and 4% for ceftolozane-tazobactam. The number of CRPA needed to test (NNT) to identify one CP-CRPA decreased from 138 to 64 if the definition of NS to cefepime or ceftazidime was used and to 7 with NS to ceftolozane-tazobactam.Conclusion: Adding not susceptible to cefepime or ceftazidime to CRPA carbapenemase testing criteria would reduce the NNT by half and can be implemented in most clinical laboratories; adding not susceptible to ceftolozane-tazobactam could be even more predictive once AST for this drug is more widely available.

BACKGROUND: Despite large reductions from 2005-2012, hospital-onset methicillin-resistant Staphylococcus aureus bloodstream infections (HO MRSA BSIs) continue be a major source of morbidity and mortality. AIM: To describe risk factors for and underlying sources of HO MRSA BSIs. METHODS: We investigated HO MRSA BSIs at eight high-burden short-stay acute care hospitals. A case was defined as first isolation of MRSA from a blood specimen collected in 2016 on hospital day >/=4 from a patient without an MRSA-positive blood culture in the 14 days prior. We reviewed case-patient demographics and risk factors by medical record abstraction. The potential clinical source(s) of infection were determined by consensus by a clinician panel. FINDINGS: Of the 195 eligible cases, 186 were investigated. Case-patients were predominantly male (63%); median age was 57 years (range 0-92). In the two weeks prior to the BSI, 88% of case-patients had indwelling devices, 31% underwent a surgical procedure, and 18% underwent dialysis. The most common locations of attribution were intensive care units (ICUs) (46%) and step-down units (19%). The most commonly identified non-mutually exclusive clinical sources were CVCs (46%), non-surgical wounds (17%), surgical site infections (16%), non-ventilator healthcare-associated pneumonia (13%), and ventilator-associated pneumonia (11%). CONCLUSIONS: Device-and procedure-related infections were common sources of HO MRSA BSIs. Prevention strategies focused on improving adherence to existing prevention bundles for device-and procedure-associated infections and on source control for ICU patients, patients with certain indwelling devices, and patients undergoing certain high-risk surgeries are being pursued to decrease HO MRSA BSI burden at these facilities.

The Division of Healthcare Quality Promotion (DHQP), within the Centers for Disease Control and Prevention (CDC), provides assistance to health departments and health care facilities investigating potential outbreaks and infection control breaches.1–3 These consultations typically involve assessments regarding potential risk of pathogen transmission and need for patient notification (ie, informing affected individuals about the outbreak or breach).4–6 These assessments can be challenging. The available information might not be sufficient to clearly characterize patient harms and infection risks. Accepted standards regarding patient notification in these situations are lacking. Stakeholder consensus on the best path forward can be difficult to obtain as the expectations of patients, health care providers, health care facilities, and public health do not always align.

BACKGROUND: Antibiotic resistance is often spread through bacterial populations via conjugative plasmids. However, plasmid transfer is not well recognized in clinical settings because of technical limitations, and health care-associated infections are usually caused by clonal transmission of a single pathogen. In 2015, multiple species of carbapenem-resistant Enterobacteriaceae (CRE), all producing a rare carbapenemase, were identified among patients in an intensive care unit. This observation suggested a large, previously unrecognized plasmid transmission chain and prompted our investigation. METHODS: Electronic medical record reviews, infection control observations, and environmental sampling completed the epidemiologic outbreak investigation. A laboratory analysis, conducted on patient and environmental isolates, included long-read whole-genome sequencing to fully elucidate plasmid DNA structures. Bioinformatics analyses were applied to infer plasmid transmission chains and results were subsequently confirmed using plasmid conjugation experiments. RESULTS: We identified 14 Verona integron-encoded metallo-ss-lactamase (VIM)-producing CRE in 12 patients, and 1 additional isolate was obtained from a patient room sink drain. Whole-genome sequencing identified the horizontal transfer of blaVIM-1, a rare carbapenem resistance mechanism in the United States, via a promiscuous incompatibility group A/C2 plasmid that spread among 5 bacterial species isolated from patients and the environment. CONCLUSIONS: This investigation represents the largest known outbreak of VIM-producing CRE in the United States to date, which comprises numerous bacterial species and strains. We present evidence of in-hospital plasmid transmission, as well as environmental contamination. Our findings demonstrate the potential for 2 types of hospital-acquired infection outbreaks: those due to clonal expansion and those due to the spread of conjugative plasmids encoding antibiotic resistance across species.

OBJECTIVE: To describe common pathogens and antimicrobial resistance patterns for healthcare-associated infections (HAIs) among pediatric patients that occurred in 2015-2017 and were reported to the Centers for Disease Control and Prevention's National Healthcare Safety Network (NHSN). METHODS: Antimicrobial resistance data were analyzed for pathogens implicated in central line-associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), ventilator-associated pneumonias (VAPs), and surgical site infections (SSIs). This analysis was restricted to device-associated HAIs reported from pediatric patient care locations and SSIs among patients <18 years old. Percentages of pathogens with nonsusceptibility (%NS) to selected antimicrobials were calculated by HAI type, location type, and surgical category. RESULTS: Overall, 2,545 facilities performed surveillance of pediatric HAIs in the NHSN during this period. Staphylococcus aureus (15%), Escherichia coli (12%), and coagulase-negative staphylococci (12%) were the 3 most commonly reported pathogens associated with pediatric HAIs. Pathogens and the %NS varied by HAI type, location type, and/or surgical category. Among CLABSIs, the %NS was generally lowest in neonatal intensive care units and highest in pediatric oncology units. Staphylococcus spp were particularly common among orthopedic, neurosurgical, and cardiac SSIs; however, E. coli was more common in abdominal SSIs. Overall, antimicrobial nonsusceptibility was less prevalent in pediatric HAIs than in adult HAIs. CONCLUSION: This report provides an updated national summary of pathogen distributions and antimicrobial resistance patterns among pediatric HAIs. These data highlight the need for continued antimicrobial resistance tracking among pediatric patients and should encourage the pediatric healthcare community to use such data when establishing policies for infection prevention and antimicrobial stewardship.

OBJECTIVE: Describe common pathogens and antimicrobial resistance patterns for healthcare-associated infections (HAIs) that occurred during 2015-2017 and were reported to the Centers for Disease Control and Prevention's (CDC's) National Healthcare Safety Network (NHSN). METHODS: Data from central line-associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), ventilator-associated events (VAEs), and surgical site infections (SSIs) were reported from acute-care hospitals, long-term acute-care hospitals, and inpatient rehabilitation facilities. This analysis included device-associated HAIs reported from adult location types, and SSIs among patients >/=18 years old. Percentages of pathogens with nonsusceptibility (%NS) to selected antimicrobials were calculated for each HAI type, location type, surgical category, and surgical wound closure technique. RESULTS: Overall, 5,626 facilities performed adult HAI surveillance during this period, most of which were general acute-care hospitals with <200 beds. Escherichia coli (18%), Staphylococcus aureus (12%), and Klebsiella spp (9%) were the 3 most frequently reported pathogens. Pathogens varied by HAI and location type, with oncology units having a distinct pathogen distribution compared to other settings. The %NS for most pathogens was significantly higher among device-associated HAIs than SSIs. In addition, pathogens from long-term acute-care hospitals had a significantly higher %NS than those from general hospital wards. CONCLUSIONS: This report provides an updated national summary of pathogen distributions and antimicrobial resistance among select HAIs and pathogens, stratified by several factors. These data underscore the importance of tracking antimicrobial resistance, particularly in vulnerable populations such as long-term acute-care hospitals and intensive care units.

BACKGROUND: CDC recently published Interim Guidance for a Public Health Response to Contain Novel or Targeted Multidrug-resistant Organisms (MDROs). We assessed the impact of implementing the strategy in a U.S. state using a mathematical model. METHODS: We used a deterministic compartmental model, parametrized via a novel analysis of Carbapenem-resistant Enterobacteriaceae (CRE) data reported to the National Healthcare Safety Network and patient transfer data from the Center for Medicare & Medicaid Services. The simulations assumed that after the importation of the MDRO and its initial detection by clinical culture at an index hospital, fortnightly prevalence surveys for colonization and additional infection control interventions were implemented at the index facility; similar surveys were then also implemented at those facilities known to be connected most strongly to it as measured by patient transfer data; and, prevalence surveys were discontinued after two consecutive negative surveys. RESULTS: If additional infection control interventions are assumed to lead to a 20% reduction in transmissibility in intervention facilities, prevalent case count in the state 3 years after importation would be reduced by 76% (IQR: 73%-77%). During the third year, these additional infection control measures would be applied in facilities accounting for 42% (37%-46%) of inpatient days. CONCLUSIONS: CDC guidance for containing MDROs, when used in combination with information on transfer of patients among hospitals, is predicted to be effective, enabling targeted and efficient use of prevention resources during an outbreak response. Even modestly effective infection control measures may lead to a substantial reduction in transmission events.

BACKGROUND: Previous reports suggested that U.S. methicillin-resistant Staphylococcus aureus (MRSA) strain epidemiology has changed since the rise of USA300 MRSA. We describe invasive MRSA trends by strain type. METHODS: Data came from five CDC Emerging Infections Program sites conducting population-based surveillance and collecting isolates for invasive MRSA (i.e., from normally sterile body sites), 2005-2013. MRSA bloodstream infection (BSI) incidence/100,000 population was stratified by strain type and epidemiologic classification of healthcare exposures. Invasive USA100 vs USA300 case characteristics from 2013 were compared through logistic regression. RESULTS: From 2005-2013, USA100 incidence decreased most notably for hospital-onset (6.1 vs 0.9 / 100,000 persons, P<0.0001) and healthcare-associated, community-onset (10.7 vs 4.9 / 100,000 persons, P<0.0001) BSIs. USA300 incidence for hospital-onset BSIs also decreased (1.5 vs 0.6 / 100,000 persons, P<0.0001). However, USA300 incidence did not significantly change for healthcare-associated, community-onset (3.9 vs 3.3 / 100,000 persons, P=0.05) or community-associated BSIs (2.5 vs 2.4 / 100,000 persons, P=0.19). Invasive MRSA was less likely to be USA300 in patients who were older (adjusted odds ratio [aOR] 0.97 per year, 95% confidence interval [CI] 0.96-0.98), previously hospitalized (aOR 0.36, 95% CI 0.24-0.54), or had central lines (aOR 0.44, 95% CI 0.27-0.74) and associated with USA300 in people who inject drugs (aOR 4.58, 95% CI 1.16-17.95). CONCLUSIONS: Most of the decline in MRSA BSIs was from decreases in USA100 BSI incidence. Prevention of USA300 MRSA BSIs in the community will be needed to further reduce burden from MRSA BSIs.

On November 1, 2016, a point prevalence survey conducted at a Chicago skilled nursing facility with ventilated residents (vSNF A) to understand the prevalence of carbapenemase-producing organisms in health care facilities in the Chicago region identified 20 patients with Verona integron-encoded metallo-beta-lactamase–producing carbapenem-resistant Pseudomonas aeruginosa (VIM-CRPA) colonization. To determine the extent of VIM-CRPA colonization at vSNF A and provide infection control recommendations, the Chicago Department of Public Health conducted an investigation. | | The first VIM-CRPA outbreak reported in the United States occurred in a Chicago acute care hospital in 2003 (1). Other outbreaks have been described; however, none was associated with a single skilled nursing facility (2–5). Carbapenemase-producing CRPA are uncommon in the United States; a surveillance pilot for CRPA at five U.S. sites identified only two carbapenemase-producing CRPA among 129 isolates tested (CDC, unpublished data, 2017).

In this pilot study, traditional culture and PCR methods were compared to the Cepheid GeneXpert IV molecular diagnostic system with the Xpert Carba-R assay (Carba-R assay) for detection of carbapenem resistance genes in primary environmental samples collected during a health care-related outbreak. Overall, traditional culture-dependent PCR and the Carba-R assay demonstrated 75% agreement. The Carba-R assay detected carbapenemase genes in five additional samples and in two samples that had additional genes when compared to culture-dependent PCR. The Carba-R assay could be useful for prioritizing further testing of environmental samples during health care-related outbreaks.IMPORTANCE Use of the Carba-R assay for detection of carbapenem-resistant Gram-negative organisms (CROs) can provide data for implementation of a rapid infection control response to minimize the spread of CROs in the health care setting.

We analyzed clinical microbiology laboratory practices for detection of multidrug-resistant Enterobacteriaceae in US short-stay acute-care hospitals using data from the National Healthcare Safety Network (NHSN) Annual Facility Survey. Half of hospitals reported testing for carbapenemases, and 1% performed routine polymyxin susceptibility testing using reference broth microdilution.

Human factors is a discipline that utilizes the “understanding of interactions among humans and other elements of a system” and methods and design principles to “optimize the human well-being and overall system performance.” 1 The field traces its origins to the study and design of human operator use of military systems and equipment. 2 Human factors approaches to certain subtopics such as accidents, human error, and warning systems have been used to improve safety in industries including aviation, aerospace, transportation, and mining. The same principles and methods can also be applied to improving safety in healthcare systems, particularly as new technologies are incorporated into healthcare delivery, in the form of medical and surgical devices, health informatics, electronic medical record clinical decision supports, and health monitoring devices.

Infections with carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) are associated with high mortality rates (1). Carbapenemases encoded on plasmids can move between bacterial strains and have the potential to rapidly increase the proportion of Enterobacteriaceae resistant to carbapenems; as such, CP-CRE have been a particular focus of public health response. Although the Enterobacteriaceae family includes approximately 50 recognized genera, surveillance for CP-CRE has focused on the organisms most associated with clinical infections: Klebsiella spp., Enterobacter spp., and Escherichia coli (2,3). CRE from other, less commonly encountered genera (hereafter referred to as less common genera) have generally not been targeted for carbapenemase testing, in part, because some of these organisms possess intrinsic resistance to the carbapenem imipenem and others express species-specific chromosomal carbapenemases. However, these organisms can also harbor plasmid-mediated carbapenemases. This report describes CP-CRE from less common genera identified through reference testing at CDC and surveillance at the Minnesota Department of Health (MDH) Public Health Laboratory.

BACKGROUND: Approaches to controlling emerging antibiotic resistance in health care settings have evolved over time. When resistance to broad-spectrum antimicrobials mediated by extended-spectrum beta-lactamases (ESBLs) arose in the 1980s, targeted interventions to slow spread were not widely promoted. However, when Enterobacteriaceae with carbapenemases that confer resistance to carbapenem antibiotics emerged, directed control efforts were recommended. These distinct approaches could have resulted in differences in spread of these two pathogens. CDC evaluated these possible changes along with initial findings of an enhanced antibiotic resistance detection and control strategy that builds on interventions developed to control carbapenem resistance. METHODS: Infection data from the National Healthcare Safety Network from 2006-2015 were analyzed to calculate changes in the annual proportion of selected pathogens that were nonsusceptible to extended-spectrum cephalosporins (ESBL phenotype) or resistant to carbapenems (carbapenem-resistant Enterobacteriaceae [CRE]). Testing results for CRE and carbapenem-resistant Pseudomonas aeruginosa (CRPA) are also reported. RESULTS: The percentage of ESBL phenotype Enterobacteriaceae decreased by 2% per year (risk ratio [RR] = 0.98, p<0.001); by comparison, the CRE percentage decreased by 15% per year (RR = 0.85, p<0.01). From January to September 2017, carbapenemase testing was performed for 4,442 CRE and 1,334 CRPA isolates; 32% and 1.9%, respectively, were carbapenemase producers. In response, 1,489 screening tests were performed to identify asymptomatic carriers; 171 (11%) were positive. CONCLUSIONS: The proportion of Enterobacteriaceae infections that were CRE remained lower and decreased more over time than the proportion that were ESBL phenotype. This difference might be explained by the more directed control efforts implemented to slow transmission of CRE than those applied for ESBL-producing strains. Increased detection and aggressive early response to emerging antibiotic resistance threats have the potential to slow further spread.

In healthcare settings, Acinetobacter spp. bacteria commonly demonstrate antimicrobial resistance, making them a major treatment challenge. Nearly half of Acinetobacter organisms from clinical cultures in the United States are nonsusceptible to carbapenem antimicrobial drugs. During 2012-2015, we conducted laboratory- and population-based surveillance in selected metropolitan areas in Colorado, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee to determine the incidence of carbapenem-nonsusceptible A. baumannii cultured from urine or normally sterile sites and to describe the demographic and clinical characteristics of patients and cases. We identified 621 cases in 537 patients; crude annual incidence was 1.2 cases/100,000 persons. Among 598 cases for which complete data were available, 528 (88.3%) occurred among patients with exposure to a healthcare facility during the preceding year; 506 (84.6%) patients had an indwelling device. Although incidence was lower than for other healthcare-associated pathogens, cases were associated with substantial illness and death.

Background: In 2007, Illinois became the first state in the United States to mandate active surveillance of methicillin-resistant Staphylococcus aureus (MRSA). The Illinois law applies to intensive care unit (ICU) patients; contact precautions are required for patients found to be MRSA-colonized. However, the effectiveness of a legislated "search and isolate" approach to reduce MRSA burden among critically ill patients is uncertain. We evaluated whether the prevalence of MRSA colonization declined in the 5 years after the start of mandatory active surveillance. Methods: All hospitals with an ICU having >/=10 beds in Chicago, Illinois, USA were eligible to participate in single-day serial point prevalence surveys. We assessed MRSA colonization among adult ICU patients present at time of survey using nasal and inguinal swab cultures. The primary outcome was region-wide MRSA colonization prevalence over time. Results: All 25 eligible hospitals (51 ICUs) participated in serial point prevalence surveys over 8 survey periods (2008 - 2013). A total of 3909 adult ICU patients participated in the point prevalence surveys, with 432 (11.1%) found to be colonized with MRSA (95% confidence interval [CI] 10.1% to 12.0%). The MRSA colonization prevalence among patients was unchanged during the study period; year-over-year relative risk for MRSA colonization was 0.97, 95% CI 0.89 to 1.05, P=0.48). Conclusions: MRSA colonization prevalence among critically ill adult patients did not decline during the time period following legislatively mandated MRSA active surveillance. Our findings highlight the limits of legislated MRSA active surveillance as a strategy to reduce MRSA colonization burden among ICU patients.

Background.: Carbapenem-resistant Enterobacteriaceae (CRE) are high-priority bacterial pathogens targeted for efforts to decrease transmissions and infections in healthcare facilities. Some regions have experienced CRE outbreaks that were likely amplified by frequent transmission in long-term acute care hospitals (LTACHs). Planning and funding intervention efforts focused on LTACHs is one proposed strategy to contain outbreaks; however, the potential regional benefits of such efforts are unclear. Methods.: We designed an agent-based simulation model of patients in a regional network of 10 healthcare facilities including 1 LTACH, 3 short-stay acute care hospitals (ACHs) and 6 nursing homes (NHs). The model was calibrated to achieve realistic patient flow and CRE transmission and detection rates. We then simulated the initiation of an entirely LTACH-focused intervention in a previously CRE-free region, including active surveillance for CRE carriers and enhanced isolation of identified carriers. Results.: When initiating the intervention at the 1st clinical CRE detection in the LTACH, cumulative CRE transmissions over 5 years across all 10 facilities were reduced by 79-93% compared to no-intervention simulations. This result was robust to changing assumptions for transmission within non-LTACH facilities and flow of patients from the LTACH. Delaying the intervention until the 20th CRE detection resulted in substantial delays in achieving optimal regional prevalence, while still reducing transmissions by 60-79% over 5 years. Conclusions.: Focusing intervention efforts on LTACHs is potentially a highly efficient strategy for reducing CRE transmissions across an entire region, particularly when implemented as early as possible in an emerging outbreak.

In 2015, scientists reported the emergence of the plasmid-encoded mcr-1 gene conferring bacterial resistance to the antibiotic colistin (1), signaling potential emergence of a pandrug-resistant bacterium. In May 2016, mcr-1-positive Escherichia coli was first isolated from a specimen from a U.S. patient (2) when a Pennsylvania woman was evaluated for a urinary tract infection. The urine culture and subsequent testing identified the gene in an extended-spectrum beta-lactamase (ESBL)-producing E. coli with reduced susceptibility to colistin. The patient had no international travel for approximately 1 year, no livestock exposure, and a limited role in meal preparation with store-bought groceries; however, she had multiple and repeated admissions to four medical facilities during 2016.

OBJECTIVE To describe antimicrobial resistance patterns for healthcare-associated infections (HAIs) that occurred in 2011-2014 and were reported to the Centers for Disease Control and Prevention's National Healthcare Safety Network. METHODS Data from central line-associated bloodstream infections, catheter-associated urinary tract infections, ventilator-associated pneumonias, and surgical site infections were analyzed. These HAIs were reported from acute care hospitals, long-term acute care hospitals, and inpatient rehabilitation facilities. Pooled mean proportions of pathogens that tested resistant (or nonsusceptible) to selected antimicrobials were calculated by year and HAI type. RESULTS Overall, 4,515 hospitals reported that at least 1 HAI occurred in 2011-2014. There were 408,151 pathogens from 365,490 HAIs reported to the National Healthcare Safety Network, most of which were reported from acute care hospitals with greater than 200 beds. Fifteen pathogen groups accounted for 87% of reported pathogens; the most common included Escherichia coli (15%), Staphylococcus aureus (12%), Klebsiella species (8%), and coagulase-negative staphylococci (8%). In general, the proportion of isolates with common resistance phenotypes was higher among device-associated HAIs compared with surgical site infections. Although the percent resistance for most phenotypes was similar to earlier reports, an increase in the magnitude of the resistance percentages among E. coli pathogens was noted, especially related to fluoroquinolone resistance. CONCLUSION This report represents a national summary of antimicrobial resistance among select HAIs and phenotypes. The distribution of frequent pathogens and some resistance patterns appear to have changed from 2009-2010, highlighting the need for continual, careful monitoring of these data across the spectrum of HAI types. Infect Control Hosp Epidemiol 2016;1-14.

We examined reported policies for the control of common multidrug-resistant organisms (MDROs) in US healthcare facilities using data from the National Healthcare Safety Network Annual Facility Survey. Policies for the use of Contact Precautions were commonly reported. Chlorhexidine bathing for preventing MDRO transmission was also common among acute care hospitals.

BACKGROUND: Antimicrobial use is common among patients receiving chronic hemodialysis (CHD) and may represent an important antimicrobial stewardship opportunity. The objective of this study is to characterize CHD patients at increased risk of receiving antimicrobials, including not indicated antimicrobials. METHODS: We conducted a prospective cohort study over a 12-month period among patients receiving CHD in 2 outpatient dialysis units. Each parenteral antimicrobial dose administered was characterized as indicated or not indicated based on national guidelines. Patient factors associated with receipt of antimicrobials and receipt of ≥1 inappropriate antimicrobial dose were analyzed. RESULTS: A total of 89 of 278 CHD patients (32%) received ≥1 antimicrobial doses and 52 (58%) received ≥1 inappropriately indicated dose. Patients with tunneled catheter access, a history of colonization or infection with a multidrug-resistant organism, and receiving CHD sessions during daytime shifts were more likely to receive antimicrobials (odds ratio [OR], 5.16; 95% confidence interval [CI], 2.72-9.80; OR, 5.43; 95% CI, 1.84-16.06; OR, 4.59; 95% CI, 1.20-17.52, respectively). Patients with tunneled catheter access, receiving CHD at dialysis unit B, and with a longer duration of CHD prior to enrollment were at higher risk of receiving an inappropriately indicated antimicrobial dose (incidence rate ratio, 2.23; 95% CI, 1.16-4.29; incidence rate ratio, 2.67; 95% CI, 1.34-5.35; incidence rate ratio, 1.11; 95% CI, 1.01-1.23, respectively). CONCLUSIONS: This study of all types of antimicrobials administered in 2 outpatient dialysis units identified several important factors to consider when developing antimicrobial stewardship programs in this health care setting.

Middle East respiratory syndrome coronavirus (MERS-CoV) infections sharply increased in the Arabian Peninsula during spring 2014. In Abu Dhabi, United Arab Emirates, these infections occurred primarily among healthcare workers and patients. To identify and describe epidemiologic and clinical characteristics of persons with healthcare-associated infection, we reviewed laboratory-confirmed MERS-CoV cases reported to the Health Authority of Abu Dhabi during January 1, 2013-May 9, 2014. Of 65 case-patients identified with MERS-CoV infection, 27 (42%) had healthcare-associated cases. Epidemiologic and genetic sequencing findings suggest that 3 healthcare clusters of MERS-CoV infection occurred, including 1 that resulted in 20 infected persons in 1 hospital. MERS-CoV in healthcare settings spread predominantly before MERS-CoV infection was diagnosed, underscoring the importance of increasing awareness and infection control measures at first points of entry to healthcare facilities.

A total of 24,092 adverse events in hemodialysis outpatients during January 2007 through April 2011 were reported to the National Healthcare Safety Network. Of 2,656 bloodstream infections, 67.3% were in patients with central venous catheters. For all events, rates associated with central venous catheters were higher than for other vascular access types.

Carbapenem-resistant Enterobacteriaceae (CRE), a group of pathogens resistant to most antibiotics and associated with high mortality, are a rising emerging public health threat. Current approaches to infection control and prevention have not been adequate to prevent spread. An important but unproven approach is to have hospitals in a region coordinate surveillance and infection control measures. Using our Regional Healthcare Ecosystem Analyst (RHEA) simulation model and detailed Orange County, California, patient-level data on adult inpatient hospital and nursing home admissions (2011-2012), we simulated the spread of CRE throughout Orange County health-care facilities under 3 scenarios: no specific control measures, facility-level infection control efforts (uncoordinated control measures), and a coordinated regional effort. Aggressive uncoordinated and coordinated approaches were highly similar, averting 2,976 and 2,789 CRE transmission events, respectively (72.2% and 77.0% of transmission events), by year 5. With moderate control measures, coordinated regional control resulted in 21.3% more averted cases (n = 408) than did uncoordinated control at year 5. Our model suggests that without increased infection control approaches, CRE would become endemic in nearly all Orange County health-care facilities within 10 years. While implementing the interventions in the Centers for Disease Control and Prevention's CRE toolkit would not completely stop the spread of CRE, it would cut its spread substantially, by half.

Among dialysis facilities participating in a bloodstream infection (BSI) prevention collaborative, access-related BSI incidence rate improvements observed immediately following implementation of a bundle of BSI prevention interventions were sustained for up to 4 years. Overall, BSI incidence remained unchanged from baseline in the current analysis.

By mid-November 2015, the Ebola virus disease (EVD) epidemic in West Africa had resulted in 28,598 suspected, probable, or confirmed cases with 11,299 deaths since the earliest cases were identified in late 2013.1 Although most patients have been treated in West Africa, a small number have received care in hospitals in the United States.2 Although little has been known regarding clinical sequelae during recovery from EVD, current reports suggest that EVD survivors may have arthralgia, hearing loss, ocular disease, and extreme fatigue.3-5 However, the duration, severity, and pathogenesis of sequelae among EVD survivors are unknown. Understanding the experiences of EVD survivors in the United States may help inform the health needs of other survivors. | From August 2, 2014, to December 31, 2014, a total of 10 adult patients with EVD were treated in U.S. hospitals; of these patients, 8 survived. During March 2015, we administered a semistructured questionnaire by telephone or in person to all survivors about symptoms, diagnostic testing, and treatment occurring any time during the recovery period. (A copy of the questionnaire is provided in the Supplementary Appendix, available with the full text of this letter at NEJM.org.) Medical records were not reviewed. At the Centers for Disease Control and Prevention (CDC), it was determined that this inquiry did not meet the definition of research under federal guidelines, so review by institutional review boards was not required.

IMPORTANCE: Carbapenem-resistant Enterobacteriaceae (CRE) are increasingly reported worldwide as a cause of infections with high-mortality rates. Assessment of the US epidemiology of CRE is needed to inform national prevention efforts. OBJECTIVE: To determine the population-based CRE incidence and describe the characteristics and resistance mechanism associated with isolates from 7 US geographical areas. DESIGN, SETTING, AND PARTICIPANTS: Population- and laboratory-based active surveillance of CRE conducted among individuals living in 1 of 7 US metropolitan areas in Colorado, Georgia, Maryland, Minnesota, New Mexico, New York, and Oregon. Cases of CRE were defined as carbapenem-nonsusceptible (excluding ertapenem) and extended-spectrum cephalosporin-resistant Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae complex, Klebsiella pneumoniae, or Klebsiella oxytoca that were recovered from sterile-site or urine cultures during 2012-2013. Case records were reviewed and molecular typing for common carbapenemases was performed. EXPOSURES: Demographics, comorbidities, health care exposures, and culture source and location. MAIN OUTCOMES AND MEASURES: Population-based CRE incidence, site-specific standardized incidence ratios (adjusted for age and race), and clinical and microbiological characteristics. Results: Among 599 CRE cases in 481 individuals, 520 (86.8%; 95% CI, 84.1%-89.5%) were isolated from urine and 68 (11.4%; 95% CI, 8.8%-13.9%) from blood. The median age was 66 years (95% CI, 62.1-65.4 years) and 284 (59.0%; 95% CI, 54.6%-63.5%) were female. The overall annual CRE incidence rate per 100000 population was 2.93 (95% CI, 2.65-3.23). The CRE standardized incidence ratio was significantly higher than predicted for the sites in Georgia (1.65 [95% CI, 1.20-2.25]; P < .001), Maryland (1.44 [95% CI, 1.06-1.96]; P = .001), and New York (1.42 [95% CI, 1.05-1.92]; P = .048), and significantly lower than predicted for the sites in Colorado (0.53 [95% CI, 0.39-0.71]; P < .001), New Mexico (0.41 [95% CI, 0.30-0.55]; P = .01), and Oregon (0.28 [95% CI, 0.21-0.38]; P < .001). Most cases occurred in individuals with prior hospitalizations (399/531 [75.1%; 95% CI, 71.4%-78.8%]) or indwelling devices (382/525 [72.8%; 95% CI, 68.9%-76.6%]); 180 of 322 (55.9%; 95% CI, 50.0%-60.8%) admitted cases resulted in a discharge to a long-term care setting. Death occurred in 51 (9.0%; 95% CI, 6.6%-11.4%) cases, including in 25 of 91 cases (27.5%; 95% CI, 18.1%-36.8%) with CRE isolated from normally sterile sites. Of 188 isolates tested, 90 (47.9%; 95% CI, 40.6%-55.1%) produced a carbapenemase. CONCLUSIONS AND RELEVANCE: In this population- and laboratory-based active surveillance system in 7 states, the incidence of CRE was 2.93 per 100000 population. Most CRE cases were isolated from a urine source, and were associated with high prevalence of prior hospitalizations or indwelling devices, and discharge to long-term care settings.

BACKGROUND: Significant progress has been made in reducing methicillin-resistant Staphylococcus aureus (MRSA) infections among hospitalized patients. However, the decreases in invasive MRSA infections among recently discharged patients have been less substantial. We assessed risk factors for developing invasive MRSA infections following acute care hospitalizations to inform prevention strategies. METHODS: We conducted a prospective, matched case-control study. A case was defined as MRSA cultured from a normally sterile body site in a patient discharged from a hospital within the prior 12 weeks. Eligible cases were identified from 15 hospitals across 6 U.S. states. For each case, two controls were matched on hospital, month of discharge, and age group. Medical record reviews and telephone interviews were performed. Conditional logistic regression was used to identify independent risk factors for post-discharge invasive MRSA. RESULTS: From February 1, 2011 through March 31, 2013, 194 cases and 388 matched controls were enrolled. The median time between hospital discharge and positive culture was 23 days (range: 1-83 days). Factors independently associated with post-discharge MRSA infection included MRSA colonization (mOR 7.71, 95%CI 3.60-16.51), discharge to a nursing home (mOR 2.65, 95%CI 1.41-4.99), presence of a chronic wound during the post-discharge period (mOR 4.41, 95%CI 2.14-9.09), and discharge with a central venous catheter (CVC) (mOR 2.16, 95%CI 1.13-4.99) or a non-CVC invasive device (mOR 3.03, 95%CI 1.24-7.39) in place. CONCLUSION: Prevention efforts should target patients with MRSA colonization or those with invasive devices or chronic wounds at hospital discharge. In addition, MRSA prevention efforts in nursing homes are warranted.

Preventing transmission of carbapenemase-producing, carbapenem-resistant Enterobacteriaceae (CP-CRE) is a public health priority. A phenotype-based definition that reliably identifies CP-CRE while minimizing misclassification of non-CP-CRE could help prevention efforts. To assess possible definitions, we evaluated enterobacterial isolates that had been tested and deemed nonsusceptible to >1 carbapenem at US Emerging Infections Program sites. We determined the number of non-CP isolates that met (false positives) and CP isolates that did not meet (false negatives) the Centers for Disease Control and Prevention CRE definition in use during our study: 30% (94/312) of CRE had carbapenemase genes, and 21% (14/67) of Klebsiella pneumoniae carbapenemase-producing Klebsiella isolates had been misclassified as non-CP. A new definition requiring resistance to 1 carbapenem rarely missed CP strains, but 55% of results were false positive; adding the modified Hodge test to the definition decreased false positives to 12%. This definition should be considered for use in carbapenemase-producing CRE surveillance and prevention.