To explore an approach to identify the risk of local prevalence of extended-spectrum β-lactamase–producing Enterobacterales (ESBL-E) on ESBL-E colonization or infection and to reassess known risk factors.

Case–control study.

Johns Hopkins Health System emergency departments (EDs) in the Baltimore–Washington, DC, region.

Patients aged ≥18 years with a culture growing Enterobacterales between April 2019 and December 2021. Cases had a culture growing an ESBL-E.

Addresses were linked to Census Block Groups and placed into communities using a clustering algorithm. Prevalence in each community was estimated using the proportion of ESBL-E among Enterobacterales isolates. Logistic regression was used to determine risk factors for ESBL-E colonization or infection.

ESBL-E were detected in 1,167 of 11,224 patients (10.4%). Risk factors included a history of ESBL-E in the prior 6 months (aOR, 20.67; 95% CI, 13.71–31.18), exposure to a skilled nursing or long-term care facility (aOR, 1.64; 95% CI, 1.37–1.96), exposure to a third-generation cephalosporin (aOR, 1.79; 95% CI, 1.46–2.19), exposure to a carbapenem (aOR, 2.31; 95% CI, 1.68–3.18), or exposure to a trimethoprim-sulfamethoxazole (aOR, 1.54; 95% CI, 1.06–2.25) within the prior 6 months. Patients were at lower risk if their community had a prevalence <25th percentile in the prior 3 months (aOR, 0.83; 95% CI, 0.71–0.98), 6 months (aOR, 0.83; 95% CI, 0.71–0.98), or 12 months (aOR, 0.81; 95% CI, 0.68–0.95). There was no association between being in a community in the >75th percentile and the outcome.

This method of defining the local prevalence of ESBL-E may partially capture differences in the likelihood of a patient having an ESBL-E.

Central-line–associated bloodstream infection (CLABSI) surveillance in home infusion therapy is necessary to track efforts to reduce infections, but a standardized, validated, and feasible definition is lacking. We tested the validity of a home-infusion CLABSI surveillance definition and the feasibility and acceptability of its implementation.

Mixed-methods study including validation of CLABSI cases and semistructured interviews with staff applying these approaches.

This study was conducted in 5 large home-infusion agencies in a CLABSI prevention collaborative across 14 states and the District of Columbia.

Staff performing home-infusion CLABSI surveillance.

From May 2021 to May 2022, agencies implemented a home-infusion CLABSI surveillance definition, using 3 approaches to secondary bloodstream infections (BSIs): National Healthcare Safety Program (NHSN) criteria, modified NHSN criteria (only applying the 4 most common NHSN-defined secondary BSIs), and all home-infusion–onset bacteremia (HiOB). Data on all positive blood cultures were sent to an infection preventionist for validation. Surveillance staff underwent semistructured interviews focused on their perceptions of the definition 1 and 3–4 months after implementation.

Interrater reliability scores overall ranged from κ = 0.65 for the modified NHSN criteria to κ = 0.68 for the NHSN criteria to κ = 0.72 for the HiOB criteria. For the NHSN criteria, the agency-determined rate was 0.21 per 1,000 central-line (CL) days, and the validator-determined rate was 0.20 per 1,000 CL days. Overall, implementing a standardized definition was thought to be a positive change that would be generalizable and feasible though time-consuming and labor intensive.

The home-infusion CLABSI surveillance definition was valid and feasible to implement.

To reduce inappropriate antibiotic prescribing for acute respiratory infections (ARIs) by employing peer comparison with behavioral feedback in the emergency department (ED).

A controlled before-and-after study.

The study was conducted in 5 adult EDs at teaching and community hospitals in a health system.

Adults presenting to the ED with a respiratory condition diagnosis code. Hospitalized patients and those with a diagnosis code for a non-respiratory condition for which antibiotics are or may be warranted were excluded.

After a baseline period from January 2016 to March 2018, 3 EDs implemented a feedback intervention with peer comparison between April 2018 and December 2019 for attending physicians. Also, 2 EDs in the health system served as controls. Using interrupted time series analysis, the inappropriate ARI prescribing rate was calculated as the proportion of antibiotic-inappropriate ARI encounters with a prescription. Prescribing rates were also evaluated for all ARIs. Attending physicians at intervention sites received biannual e-mails with their inappropriate prescribing rate and had access to a dashboard that was updated daily showing their performance relative to their peers.

Among 28,544 ARI encounters, the inappropriate prescribing rate remained stable at the control EDs between the 2 periods (23.0% and 23.8%). At the intervention sites, the inappropriate prescribing rate decreased significantly from 22.0% to 15.2%. Between periods, the overall ARI prescribing rate was 38.1% and 40.6% in the control group and 35.9% and 30.6% in the intervention group.

Behavioral feedback with peer comparison can be implemented effectively in the ED to reduce inappropriate prescribing for ARIs.

Targeted screening for carbapenem-resistant organisms (CROs), including carbapenem-resistant Enterobacteriaceae (CRE) and carbapenemase-producing organisms (CPOs), remains limited; recent data suggest that existing policies miss many carriers.

Our objective was to measure the prevalence of CRO and CPO perirectal colonization at hospital unit admission and to use machine learning methods to predict probability of CRO and/or CPO carriage.

We performed an observational cohort study of all patients admitted to the medical intensive care unit (MICU) or solid organ transplant (SOT) unit at The Johns Hopkins Hospital between July 1, 2016 and July 1, 2017. Admission perirectal swabs were screened for CROs and CPOs. More than 125 variables capturing preadmission clinical and demographic characteristics were collected from the electronic medical record (EMR) system. We developed models to predict colonization probabilities using decision tree learning.

Evaluating 2,878 admission swabs from 2,165 patients, we found that 7.5% and 1.3% of swabs were CRO and CPO positive, respectively. Organism and carbapenemase diversity among CPO isolates was high. Despite including many characteristics commonly associated with CRO/CPO carriage or infection, overall, decision tree models poorly predicted CRO and CPO colonization (C statistics, 0.57 and 0.58, respectively). In subgroup analyses, however, models did accurately identify patients with recent CRO-positive cultures who use proton-pump inhibitors as having a high likelihood of CRO colonization.

In this inpatient population, CRO carriage was infrequent but was higher than previously published estimates. Despite including many variables associated with CRO/CPO carriage, models poorly predicted colonization status, likely due to significant host and organism heterogeneity.

To explore current practices and decision making regarding antimicrobial prescribing among emergency department (ED) clinical providers.

We conducted a survey of ED providers recruited from 8 sites in 3 cities. Using purposeful sampling, we then recruited 21 providers for in-depth interviews. Additionally, we observed 10 patient-provider interactions at one of the ED sites. SAS 9.3 was used for descriptive and predictive statistics. Interviews were audio recorded, transcribed, and analyzed using a thematic, constructivist approach with consensus coding using NVivo 10.0. Field and interview notes collected during the observational study were aligned with themes identified through individual interviews.

Of 150 survey respondents, 76% agreed or strongly agreed that antibiotics are overused in the ED, while half believed they personally did not overprescribe. Eighty-nine percent used a smartphone or tablet in the ED for antibiotic prescribing decisions. Several significant differences were found between attending and resident physicians. Interview analysis identified 42 codes aggregated into the following themes: (1) resource and environmental factors that affect care; (2) access to and quality of care received outside of the ED consult; (3) patient-provider relationships; (4) clinical inertia; and (5) local knowledge generation. The observational study revealed limited patient understanding of antibiotic use. Providers relied heavily upon diagnostics and provided limited education to patients. Most patients denied a priori expectations of being prescribed antibiotics.

Patient, provider, and healthcare system factors should be considered when designing interventions to improve antimicrobial stewardship in the ED setting.

Infect Control Hosp Epidemiol 2014;35(9):1114-1125

Multidrug-resistant Enterobacteriaceae pose a serious infection control challenge and have emerged as a public health threat. We examined national trends in the proportion of Klebsiella pneumoniae isolates resistant to carbapenems (CRKP) and third-generation cephalosporins (G3CRKP).

Retrospective analysis of approximately 500,000 K. pneumoniae isolates cultured between January 1999 and July 2010 at 287 clinical laboratories throughout the United States.

Isolates were defined as CRKP if they were nonsusceptible to 1 or more carbapenems and were defined as G3CRKP if they were nonsusceptible to ceftazidime, ceftriaxone, or related antibiotics. A multivariable analysis examined trends in the proportion of resistant isolates, adjusting for age, sex, isolate source, patient location, and geographic region.

The crude proportion of CRKP increased from less than 0.1% to 4.5% between 2002 and 2010; the frequency of G3CRKP increased from 5.3% to 11.5% between 1999 and 2010. G3CRKP and CRKP were more common among elderly patients (those greater than 65 years of age); the adjusted odds ratio (aOR) relative to pediatric patients (those less than 18 years of age) was 1.2 for G3CRKP (95% confidence interval [CI], 1.2–1.3) and 3.3 for CRKP (95% CI, 2.6–4.2). G3CRKP and CRKP were also more common among patients from the northeastern United States (aOR, 2.9 [95% CI, 2.8–3.0] and 9.0 [95% CI, 7.9–10.4]) than among those from the western United States. The prevalence of outpatient CRKP isolates increased after 2006, reaching 1.9% of isolates in our sample in 2010 (95% CI, 1.6%–2.1%).

The frequency of G3CRKP and CRKP is increasing in all regions of the United States, and resistance is emerging among isolates recovered in the outpatient setting. This underscores the need for enhanced laboratory capacity and coordinated surveillance strategies to contain the further spread of these emerging pathogens.