Multispecies Outbreak of Verona Integron-Encoded Metallo-ß-Lactamase-Producing Multidrug Resistant Bacteria Driven by a Promiscuous Incompatibility Group A/C2 Plasmid.

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.

Antimicrobial Susceptibility Profiles To Predict the Presence of Carbapenemase Genes among Carbapenem-Resistant Pseudomonas aeruginosa Isolates.

Detection of carbapenem-resistant Pseudomonas aeruginosa (CRPA) with carbapenemase-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. We defined CRPA as P. aeruginosa with imipenem or meropenem MICs of ≥8 µg/ml; CP-CRPA was CRPA with CP genes (blaKPC/blaIMP/blaNDM/blaOXA-48/blaVIM). We assessed the sensitivity and specificity of AST profiles to detect CP-CRPA among CRPA isolates collected by CDC's Antibiotic Resistance Laboratory Network (AR Lab Network) and the Emerging Infections Program (EIP) during 2017 to 2019. Three percent (195/6,192) of AR Lab Network CRPA isolates were CP-CRPA. Among CRPA isolates, adding not susceptible (NS) to cefepime or ceftazidime to the definition had 91% sensitivity and 50% specificity for identifying CP-CRPA; adding NS to ceftolozane-tazobactam had 100% sensitivity and 86% specificity. Of 965 EIP CRPA isolates evaluated for CP genes, 7 were identified as CP-CRPA; 6 of the 7 were NS to cefepime and ceftazidime, and all 7 were NS to ceftolozane-tazobactam. Among 4,182 EIP isolates, clinical laboratory AST results were available for 96% of them for cefepime, 80% for ceftazidime, and 4% for ceftolozane-tazobactam. The number of CRPA isolates needed to test (NNT) to identify one CP-CRPA isolate decreased from 138 to 64 if the definition of NS to cefepime or ceftazidime was used and to 7 with NS to ceftolozane-tazobactam. 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.

Modeling Regional Transmission and Containment of a Healthcare-associated Multidrug-resistant Organism.

BACKGROUND: The Centers for Disease Control and Prevention (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 US state using a mathematical model. METHODS: We used a deterministic compartmental model, parametrized via a novel analysis of carbapenem-resistant Enterobacteriaceae data reported to the National Healthcare Safety Network and patient transfer data from the Centers for Medicare and 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 2 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% (interquartile range: 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.

Trends in Incidence of Methicillin-resistant Staphylococcus aureus Bloodstream Infections Differ by Strain Type and Healthcare Exposure, United States, 2005-2013.

BACKGROUND: Previous reports suggested that US 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 5 Centers for Disease Control and Prevention Emerging Infections Program sites conducting population-based surveillance and collecting isolates for invasive MRSA (ie, from normally sterile body sites), 2005-2013. MRSA bloodstream infection (BSI) incidence per 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 to 2013, USA100 incidence decreased most notably for hospital-onset (6.1 vs 0.9/100 000 persons, P < .0001) and healthcare-associated, community-onset (10.7 vs 4.9/100 000 persons, P < .0001) BSIs. USA300 incidence for hospital-onset BSIs also decreased (1.5 vs 0.6/100 000 persons, P < .0001). However, USA300 incidence did not significantly change for healthcare-associated, community-onset (3.9 vs 3.3/100 000 persons, P = .05) or community-associated BSIs (2.5 vs 2.4/100 000 persons, P = .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}, .96-.98]), previously hospitalized (aOR, 0.36 [95% CI, .24-.54]), or had central lines (aOR, 0.44 [95% CI, .27-.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.

Carbapenem-Resistant Pseudomonas aeruginosa at US Emerging Infections Program Sites, 2015.

Pseudomonas aeruginosa is intrinsically resistant to many antimicrobial drugs, making carbapenems crucial in clinical management. During July-October 2015 in the United States, we piloted laboratory-based surveillance for carbapenem-resistant P. aeruginosa (CRPA) at sentinel facilities in Georgia, New Mexico, Oregon, and Tennessee, and population-based surveillance in Monroe County, NY. An incident case was the first P. aeruginosa isolate resistant to antipseudomonal carbapenems from a patient in a 30-day period from any source except the nares, rectum or perirectal area, or feces. We found 294 incident cases among 274 patients. Cases were most commonly identified from respiratory sites (120/294; 40.8%) and urine (111/294; 37.8%); most (223/280; 79.6%) occurred in patients with healthcare facility inpatient stays in the prior year. Genes encoding carbapenemases were identified in 3 (2.3%) of 129 isolates tested. The burden of CRPA was high at facilities under surveillance, but carbapenemase-producing CRPA were rare.

Approach to the Investigation and Management of Patients With Candida auris, an Emerging Multidrug-Resistant Yeast.

Candida auris is an emerging, multidrug-resistant yeast that can spread in healthcare settings. It can cause invasive infections with high mortality and is difficult to identify using traditional yeast identification methods. Candida auris has been reported in more than a dozen countries, and as of August 2017, 112 clinical cases have been reported in the United States. Candida auris can colonize skin and persist in the healthcare environment, allowing for transmission between patients. Prompt investigation and aggressive interventions, including notification to public health agencies, implementation of contact precautions, thorough environmental cleaning and disinfection, infection control assessments, contact tracing and screening of contacts to assess for colonization, and retrospective review of microbiology records and prospective surveillance for cases at laboratories are all needed to limit the spread of C. auris. This review summarizes the current recommended approach to manage cases and control transmission of C. auris in healthcare facilities.

Regional Epidemiology of Methicillin-Resistant Staphylococcus aureus Among Adult Intensive Care Unit Patients Following State-Mandated Active Surveillance.

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, 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%-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, .89-1.05; P = .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.

Carbapenem-Nonsusceptible Acinetobacter baumannii, 8 US Metropolitan Areas, 2012-2015.

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.

Vital Signs: Containment of Novel Multidrug-Resistant Organisms and Resistance Mechanisms - United States, 2006-2017.

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 ß-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.

The Potential for Interventions in a Long-term Acute Care Hospital to Reduce Transmission of Carbapenem-Resistant Enterobacteriaceae in Affiliated Healthcare Facilities.

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 of 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 first 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.

Risk Factors for Invasive Methicillin-Resistant Staphylococcus aureus Infection After Recent Discharge From an Acute-Care Hospitalization, 2011-2013.

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. To inform prevention strategies, we assessed risk factors for invasive MRSA infection after acute-care hospitalizations. 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 case patients were identified from 15 hospitals across 6 US states. For each case patient, 2 controls were matched for 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 postdischarge invasive MRSA. RESULTS: From 1 February 2011 through 31 March 2013, 194 case patients 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 postdischarge MRSA infection included MRSA colonization (matched odds ratio [mOR], 7.71; 95% confidence interval [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 postdischarge period (mOR, 4.41; 95% CI, 2.14-9.09), and discharge with a central venous catheter (mOR, 2.16; 95% CI, 1.13-4.99) or a different invasive device (mOR, 3.03; 95% CI, 1.24-7.39) in place. CONCLUSIONS: 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.

Transmission of Middle East Respiratory Syndrome Coronavirus Infections in Healthcare Settings, Abu Dhabi.

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.

The Potential Trajectory of Carbapenem-Resistant Enterobacteriaceae, an Emerging Threat to Health-Care Facilities, and the Impact of the Centers for Disease Control and Prevention Toolkit.

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.

Investigation of First Identified mcr-1 Gene in an Isolate from a U.S. Patient - Pennsylvania, 2016.

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.

Carbapenem-Resistant Enterobacteriaceae Transmission in Health Care Facilities - Wisconsin, February-May 2015.

Carbapenem-resistant Enterobacteriaceae (CRE) are multidrug-resistant gram-negative bacilli that can cause infections associated with high case fatality rates, and are emerging as epidemiologically important health care-associated pathogens in the United States (1). Prevention of CRE transmission in health care settings is dependent on recognition of cases, isolation of colonized and infected patients, effective use of infection control measures, and the correct use of antibiotics. The use of molecular technologies, including polymerase chain reaction (PCR) testing, pulsed-field gel electrophoresis (PFGE), and whole genome sequencing (WGS), can lead to detection of transmission events and interruption of transmission. In Wisconsin, acute care and critical access hospitals report laboratory-identified CRE to the Wisconsin Division of Public Health (WDPH), and clinical laboratories submit CRE isolates to the Wisconsin State Laboratory of Hygiene (WSLH) for molecular testing. During February-May 2015, a total of 49 CRE isolates from 46 patients were submitted to WSLH. On June 8, WSLH informed WDPH of five carbapenemase-producing CRE isolates with closely related PFGE patterns identified among four inpatients at two hospitals in southeastern Wisconsin. An investigation revealed a high degree of genetic relatedness among the patients' isolates, but did not identify the mechanism of transmission between the two facilities. No breaches in recommended practices were identified; after reviewing respiratory care procedures, no further cases were identified. Routine hospital- and laboratory-based surveillance can detect and prevent health care transmission of CRE.

Active Tracing and Monitoring of Contacts Associated With the First Cluster of Ebola in the United States.

BACKGROUND: Following hospitalization of the first patient with Ebola virus disease diagnosed in the United States on 28 September 2014, contact tracing methods for Ebola were implemented. OBJECTIVE: To identify, risk-stratify, and monitor contacts of patients with Ebola. DESIGN: Descriptive investigation. SETTING: Dallas County, Texas, September to November 2014. PARTICIPANTS: Contacts of symptomatic patients with Ebola. MEASUREMENTS: Contact identification, exposure risk classification, symptom development, and Ebola. RESULTS: The investigation identified 179 contacts, 139 of whom were contacts of the index patient. Of 112 health care personnel (HCP) contacts of the index case, 22 (20%) had known unprotected exposures and 37 (30%) did not have known unprotected exposures but interacted with a patient or contaminated environment on multiple days. Transmission was confirmed in 2 HCP who had substantial interaction with the patient while wearing personal protective equipment. These HCP had 40 additional contacts. Of 20 community contacts of the index patient or the 2 HCP, 4 had high-risk exposures. Movement restrictions were extended to all 179 contacts; 7 contacts were quarantined. Seven percent (14 of 179) of contacts (1 community contact and 13 health care contacts) were evaluated for Ebola during the monitoring period. LIMITATION: Data cannot be used to infer whether in-person direct active monitoring is superior to active monitoring alone for early detection of symptomatic contacts. CONCLUSION: Contact tracing and monitoring approaches for Ebola were adapted to account for the evolving understanding of risks for unrecognized HCP transmission. HCP contacts in the United States without known unprotected exposures should be considered as having a low (but not zero) risk for Ebola and should be actively monitored for symptoms. Core challenges of contact tracing for high-consequence communicable diseases included rapid comprehensive contact identification, large-scale direct active monitoring of contacts, large-scale application of movement restrictions, and necessity of humanitarian support services to meet nonclinical needs of contacts. PRIMARY FUNDING SOURCE: None.

Improved Phenotype-Based Definition for Identifying Carbapenemase Producers among Carbapenem-Resistant Enterobacteriaceae.

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.

Notes from the Field: Carbapenem-resistant Enterobacteriaceae Producing OXA-48-like Carbapenemases--United States, 2010-2015.

Carbapenem-resistant Enterobacteriaceae (CRE) are bacteria that are often resistant to most classes of antibiotics and cause health care-associated infections with high mortality rates. Among CRE, strains that carry plasmid-encoded carbapenemase enzymes that inactivate carbapenem antibiotics are of greatest public health concern because of their potential for rapid global dissemination, as evidenced by the increasing distribution of CRE that produce the Klebsiella pneumoniae carbapenemase and the New Delhi metallo-ß-lactamase. Newly described resistance in Enterobacteriaceae, such as plasmid-mediated resistance to the last-line antimicrobial colistin, recently detected in China, and resistance to the newly approved antimicrobial, ceftazidime-avibactam, identified from a U.S. K. pneumoniae carbapenemase-producing isolate, highlight the continued urgency to delay spread of CRE. Monitoring the emergence of carbapenemases is crucial to limiting their spread; identification of patients carrying carbapenemase-producing CRE should result in the institution of transmission-based precautions and enhanced environmental cleaning to prevent transmission.* The OXA-48 carbapenemase was first identified in Enterobacteriaceae in Turkey in 2001, and OXA-48-like variants have subsequently been reported around the world. The first U.S. reports of OXA-48-like carbapenemases were published in 2013 and included retrospectively identified isolates from 2009 and two isolates collected in 2012 from patients in Virginia who had recently been hospitalized outside the United States. Although there are limited additional published reports from the United States, CDC continues to receive reprots of these organisms. This report describes patients identified as carrying CRE producing OXA-48-like carbapenemases in the United States during June 2010-August 2015.

Vancomycin-Resistant Staphylococcus aureus - Delaware, 2015.

Vancomycin-resistant Staphylococcus aureus (VRSA) is a rare, multidrug-resistant bacterium of public health concern that emerged in the United States in 2002. VRSA (S. aureus with vancomycin minimum inhibitory concentration [MIC] ≥16 µg/mL) arises when vancomycin resistance genes (e.g., the vanA operon, which codes for enzymes that result in modification or elimination of the vancomycin binding site) from vancomycin-resistant enterococci (VRE) are transferred to S. aureus (1). To date, all VRSA strains have arisen from methicillin-resistant S. aureus (MRSA). The fourteenth VRSA isolate (VRSA 14) identified in the United States was reported to CDC in February 2015.

Notes from the field: Adverse events associated with administration of simulation intravenous fluids to patients--United States, 2014.

On December 23, 2014, the New York State Department of Health (NYSDOH) was notified of adverse health events in two patients who had been inadvertently administered nonsterile, simulation 0.9% sodium chloride intravenous (IV) fluids at an urgent care facility. Simulation saline is a nonsterile product not meant for human or animal use; it is intended for use by medical trainees practicing IV administration of saline on mannequins or other training devices. Both patients experienced a febrile illness during product administration and were hospitalized; one patient developed sepsis and disseminated intravascular coagulation. Neither patient died. Staff members at the clinic reported having ordered the product through their normal medical supply distributor and not recognizing during administration that it was not intended for human use.