In the era of widespread resistance, there are 2 time points at which most empiric prescription errors occur among hospitalized adults: (1) upon admission (UA) when treating patients at risk of multidrug-resistant organisms (MDROs) and (2) during hospitalization, when treating patients at risk of extensively drug-resistant organisms (XDROs). These errors adversely influence patient outcomes and the hospital’s ecology.

Retrospective cohort study, Shamir Medical Center, Israel, 2016.

Adult patients (aged >18 years) hospitalized with sepsis.

Logistic regressions were used to develop predictive models for (1) MDRO UA and (2) nosocomial XDRO. Their performances on the derivation data sets, and on 7 other validation data sets, were assessed using the area under the receiver operating characteristic curve (ROC AUC).

In total, 4,114 patients were included: 2,472 patients with sepsis UA and 1,642 with nosocomial sepsis. The MDRO UA score included 10 parameters, and with a cutoff of ≥22 points, it had an ROC AUC of 0.85. The nosocomial XDRO score included 7 parameters, and with a cutoff of ≥36 points, it had an ROC AUC of 0.87. The range of ROC AUCs for the validation data sets was 0.7–0.88 for the MDRO UA score and was 0.66–0.75 for nosocomial XDRO score. We created a free web calculator (https://assafharofe.azurewebsites.net).

A simple electronic calculator could aid with empiric prescription during an encounter with a septic patient. Future implementation studies are needed to evaluate its utility in improving patient outcomes and in reducing overall resistances.

Administration of antimicrobials to patients with asymptomatic bacteriuria (ASB) is a common error that can lead to worse outcomes. However, controlled analyses quantifying the commonality and impact of this practice are lacking. We analyzed the independent predictors for antimicrobials misuse in ASB and quantified the impact of this practice on clinical outcomes.

Retrospective case-control and cohort analyses for calendar year 2017.

Tertiary-care, university-affiliated medical center.

The study included adult (>18 years) patients with positive urine culture. Pregnant women, renal transplant recipients, and patients who underwent urologic procedures were excluded.

ASB was determined according to US Centers for Disease Control and Prevention (CDC) criteria. Multivariable logistic regression models were constructed to analyze predictors and outcomes associated with antimicrobial use for patients with ASB.

The study included 1,530 patient-unique positive urine cultures. Among these patients, 610 patients (40%) were determined to have ASB. Of the 696 isolates, 219 (36%) were multidrug-resistant organisms (MDROs). Also, 178 (29%) patients received antimicrobials specifically due to the ASB. Independent predictors for improper administration of antimicrobials were dependent functional status (adjusted odds ratio [aOR], 2.3; 95% CI, 1.4–3.6) and male sex (aOR, 2; 95% CI, 1.25–2.6). Use of antimicrobials was independently associated with re-hospitalizations (aOR, 1.7; 95% CI, 1.1–2.6) and later, acute Clostridioides difficile infections (CDI) in the following 90 days (aOR, 4.5; 95% CI, 2–10.6).

ASB is a common condition, frequently resulting from an MDRO. Male sex and poor functional status were independent predictors for mistreatment, and this practice was independently associated with rehospitalizations and CDI in the following 90 days.

The pandemic of carbapenem-resistant Enterobacteriaceae (CRE) was primarily due to clonal spread of blaKPC producing Klebsiella pneumoniae. Thus, thoroughly studied CRE cohorts have consisted mostly of K. pneumoniae.

To conduct an extensive epidemiologic analysis of carbapenem-resistant Enterobacter spp. (CREn) from 2 endemic and geographically distinct centers.

CREn were investigated at an Israeli center (Assaf Harofeh Medical Center, January 2007 to July 2012) and at a US center (Detroit Medical Center, September 2008 to September 2009). blaKPC genes were queried by polymerase chain reaction. Repetitive extragenic palindromic polymerase chain reaction and pulsed-field gel electrophoresis were used to determine genetic relatedness.

In this analysis, 68 unique patients with CREn were enrolled. Sixteen isolates (24%) were from wounds, and 33 (48%) represented colonization only. All isolates exhibited a positive Modified Hodge Test, but only 93% (27 of 29) contained blaKPC. Forty-three isolates (63%) were from elderly adults, and 5 (7.4%) were from neonates. Twenty-seven patients died in hospital (40.3% of infected patients). Enterobacter strains consisted of 4 separate clones from Assaf Harofeh Medical Center and of 4 distinct clones from Detroit Medical Center.

In this study conducted at 2 distinct CRE endemic regions, there were unique epidemiologic features to CREn: (i) polyclonality, (ii) neonates accounting for more than 7% of cohort, and (iii) high rate of colonization (almost one-half of all cases represented colonization). Since false-positive Modified Hodge Tests in Enterobacter spp. are common, close monitoring of carbapenem resistance mechanisms (particularly carbapenemase production) among Enterobacter spp. is important.

Infect. Control Hosp. Epidemiol. 2015;36(11):1283–1291

Carbapenem-resistant Enterobacteriaceae (CRE) are clinically challenging, threaten patient safety, and represent an emerging public health issue. CRE reporting is not mandated in Michigan.

The Michigan Department of Community Health–led CRE Surveillance and Prevention Initiative enrolled 21 facilities (17 acute care and 4 long-term acute care facilities) across the state. Baseline data collection began September 1, 2012, and ended February 28, 2013 (duration, 6 months). Enrolled facilities voluntarily reported cases of Klebsiella pneumoniae and Escherichia coli according to the surveillance algorithm. Patient demographic characteristics, laboratory testing, microbiology, clinical, and antimicrobial information were captured via standardized data collection forms. Facilities reported admissions and patient-days each month.

One-hundred two cases over 957,220 patient-days were reported, resulting in a crude incidence rate of 1.07 cases per 10,000 patient-days. Eighty-nine case patients had test results positive for K. pneumoniae, whereas 13 had results positive for E. coli. CRE case patients had a mean age of 63 years, and 51% were male. Urine cultures (61%) were the most frequently reported specimen source. Thirty-five percent of cases were hospital onset; sixty-five percent were community onset (CO), although 75% of CO case patients reported healthcare exposure within the previous 90 days. Cardiovascular disease, renal failure, and diabetes mellitus were the most frequently reported comorbid conditions. Common ris k factors included surgery within the previous 90 days, recent infection or colonization with a multidrug-resistant organism, and recent exposures to antimicrobials, especially third- or fourth-generation cephalosporins.

CRE are found throughout Michigan healthcare facilities. Implementing a regional, coordinated surveillance and prevention initiative may prevent CRE from becoming hyperendemic in Michigan.

This study aimed to identify risk factors associated with carbapenem-resistant Enterobacteriaceae (CRE) colonization among patients screened with rectal cultures upon admission to a hospital or long-term acute care (LTAC) center and to compare risk factors among patients who were screen positive for CRE at the time of hospital admission with those screen positive prior to LTAC admission.

A retrospective nested matched case-control study was conducted from June 2009 to December 2011. Patients with recent LTAC exposure were screened for CRE carriage at the time of hospital admission, and patients admitted to a regional LTAC facility were screened prior to LTAC admission. Cases were patients with a positive CRE screening culture, and controls (matched in a 3:1 ratio to cases) were patients with negative screening cultures.

Nine hundred five cultures were performed on 679 patients. Forty-eight (7.1%) cases were matched to 144 controls. One hundred fifty-eight patients were screened upon hospital admission and 521 prior to LTAC admission. Independent predictors for CRE colonization included Charlson's score greater than 3 (odds ratio [OR], 4.85 [95% confidence interval (CI), 1.64–14.41]), immunosuppression (OR, 3.92 [95% CI, 1.08–1.28]), presence of indwelling devices (OR, 5.21 [95% CI, 1.09–2.96]), and prior antimicrobial exposures (OR, 3.89 [95% CI, 0.71–21.47]). Risk factors among patients screened upon hospital admission were similar to the entire cohort. Among patients screened prior to LTAC admission, the characteristics of the CRE-colonized and noncolonized patients were similar.

These results can be used to identify patients at increased risk for CRE colonization and to help target active surveillance programs in healthcare settings.

To determine whether increases in contact isolation precautions are associated with decreased adherence to isolation practices among healthcare workers (HCWs).

Prospective cohort study from February 2009 to October 2009.

Eleven teaching hospitals.

HCWs.

One thousand thirteen observations conducted on HCWs. Additional data included the number of persons in isolation, types of HCWs, and hospital-specific contact precaution practices. Main outcome measures included compliance with individual components of contact isolation precautions (hand hygiene before and after patient encounter, donning of gown and glove upon entering a patient room, and doffing upon exiting) and overall compliance (all 5 measures together) during varying burdens of isolation.

Compliance with hand hygiene was as follows: prior to donning gowns/gloves, 37.2%; gowning, 74.3%; gloving, 80.1%; doffing of gowns/gloves, 80.1%; after gown/glove removal, 61%. Compliance with all components was 28.9%. As the burden of isolation increased (20% or less to greater than 60%), a decrease in compliance with hand hygiene (43.6%—4.9%) and with all 5 components (31.5%—6.5%) was observed. In multivariable analysis, there was an increase in noncompliance with all 5 components of the contact isolation precautions bundle (odds ratio [OR], 6.6 [95% confidence interval (CI), 1.15-37.44]; P = .03) and in noncompliance with hand hygiene prior to donning gowns and gloves (OR, 10.1 [95% CI, 1.84—55.54]; P = .008) associated with increasing burden of isolation.

As the proportion of patients in contact isolation increases, compliance with contact isolation precautions decreases. Placing 40% of patients under contact precautions represents a tipping point for noncompliance with contact isolation precautions measures.

To assess the impact of active alerting of positive blood culture data coupled with stewardship intervention on time to appropriate therapy, length of stay, and mortality in patients with gram-negative bacteremia.

Quasi-experimental retrospective cohort study in patients with gram-negative bacteremia at the Detroit Medical Center from 2009 to 2011.

Three hospitals (1 community, 2 academic) with active antimicrobial stewardship programs within the Detroit Medical Center.

All patients with monomicrobial gram-negative bacteremia during the study period.

Active alerting of positive blood culture data coupled with stewardship intervention (2010-2011) compared with patients who received no formalized stewardship intervention (2009).

Active alerting and intervention led to a decreased time to appropriate therapy (8 [interquartile range (IQR), 2-24] vs 14 [IQR, 2-35] hours; P = .014) in patients with gram-negative bacteremia. After controlling for differences between groups, being in the intervention arm was associated with an independent reduction in length of stay (odds ratio [OR], 0.73 [95% confidence interval (CI), 0.62-0.86]), correlating to a median attributable decrease in length of stay of 2.2 days. Additionally, multivariate modeling of patients who were not on appropriate antimicrobial therapy at the time of initial culture positivity showed that patients in the intervention group had a significant reduction in both length of stay (OR, 0.76 [95% CI, 0.66-0.86]) and infection-related mortality (OR, 0.24 [95% CI, 0.08-0.76]).

Active alerting coupled with stewardship intervention in patients with gram-negative bacteremia positively impacted time to appropriate therapy, length of stay, and mortality and should be a target of antimicrobial stewardship programs.

Carbapenem-resistant Enterobacteriaceae (CRE) are rapidly emerging worldwide. Control group selection is critically important when analyzing predictors of antimicrobial resistance. Focusing on modifiable risk factors can optimize prevention and resource expenditures. To identify specific predictors of CRE, patients with CRE were compared with 3 control groups: (1) patients with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, (2) patients with non-ESBL-containing Enterobacteriaceae, and (3) uninfected controls.

Matched multivariable analyses.

Patients possessing CRE that were isolated at Detroit Medical Center from September 1, 2008, to August 31, 2009.

Patients were matched (1:1 ratio) to the 3 sets of controls. Matching parameters included (1) bacteria type, (2) hospital/ facility, (3) unit/clinic, (4) calendar year, and (5) time at risk (ie, from admission to culture). Matched multivariable analyses were conducted between uninfected controls and patients with CRE, ESBL, and non-ESBL Enterobacteriaceae. Models were also designed comparing patients with CRE to patients with ESBL, patients with non-ESBL Enterobacteriaceae, and all 3 non-CRE groups combined.

Ninety-one unique patients with CRE were identified, and 6 matched models were constructed. Recent (less than 3 months) exposure to antibiotics was the only parameter that was consistently associated with CRE, regardless of the group to which CRE was compared, and was not independently associated with isolation of ESBL or non-ESBL Enterobacteriaceae.

Exposure to antibiotics within 3 months was an independent predictor that characterized patients with CRE isolation. As a result, antimicrobial stewardship efforts need to become a major focus of preventive Interventions. Regulatory focus regarding appropriate antimicrobial use might decrease the detrimental effects of antibiotic misuse and spread of CRE.

Carbapenem-resistant Enterobacteriaceae (CRE) are rapidly emerging in hospitals in the United States and are posing a significant threat. To better understand the transmission dynamics and the acquisition of resistant strains, a thorough analysis of epidemiologic and molecular characteristics was performed.

CRE isolated at Detroit Medical Center were analyzed from September 2008 to September 2009. blaKPC genes were investigated by polymerase chain reaction (PCR), and repetitive extragenic palindromic PCR (rep-PCR) was used to determine genetic similarity among strains. Epidemiologic and outcomes analyses were performed.

Ninety-two unique patient CRE isolates were recovered. Sixty-eight strains (74%) were Klebsiella pneumoniae, 7 were Klebsiella oxytoca, 15 were Enterobacter species, and 2 were Escherichia coli. Fifteen isolates (16%) were resistant to Colistin, 14 (16%) were resistant to tigecycline, and 2 were resistant to all antimicrobials tested. The mean ± standard deviation age of patients was 63 ± 2 years. Sixty patients (68%) were admitted to the hospital from long-term care facilities. Only 70% of patients received effective antimicrobial therapy when infection was suspected, with a mean time to appropriate therapy of 120 ± 23 hours following sample culturing. The mean length of hospitalization after sample culturing was 18.6 ± 2.5 days. Of 57 inpatients, 18 (32%) died in the hospital. Independent predictors for mortality were intensive care unit stay (odds ratio [OR], 15.8; P = .003) and co-colonization with CRE and either Acinetobacter baumannii or Pseudomonas aeruginosa (OR, 17.2; P = .006). Among K. pneumoniae CRE, rep-PCR revealed 2 genetically related strains that comprised 70% and 20% of isolates, respectively.

In this large U.S. cohort of patients with CRE infection, which reflects the modern continuum of medical care, co-colonization with CRE and A. baumannii or P. aeruginosa was associated with increased mortality. Two predominant clones of K. pneumoniae accounted for the majority of cases of CRE infection.

To perform a molecular and epidemiologic investigation of multidrug-resistant (MDR) Acinetobacter baumannii in an institution were polyclonal outbreaks have been observed and determine whether these polyclonal outbreaks had an endogenous origin or were caused by in-hospital patient-to-patient transmission.

Retrospective analysis of prospectively collected data.

An epidemiologic and genotypic investigation of incident cases of MDR A. baumannii infection in an Israeli university tertiary care center.

Hospitalized patients with MDR A. baumannii isolated from clinical samples during a 13-week period, from April 15, 2003, through July 15, 2003.

All patients with new MDR A. baumannii infections were recruited, and isolates were typed using pulsed-field gel electrophoresis. Data on in-hospital movements and consultations were extracted from computerized databases. Quantification of transmission opportunities (TOPs), defined as encounters between an established carrier and a future carrier of MDR A. baumannii, and analysis of ward clusters were performed.

We studied 96 MDR A. baumannii isolates, which belonged to 18 different pulsed-field gel electrophoresis clones. In 65% of cases, TOPs involving patients with the same clone were demonstrated, which is significantly greater than the number of TOPs involving patients with different clones (P = .01).

Although outbreaks of MDR A. baumannii infection may be polyclonal, we believe that patient-to-patient transmission explains most cases of transmission. Polyclonal local outbreaks reflect several clonal outbreaks occurring simultaneously. The cause of polyclonal outbreaks of A. baumannii infections clustered by ward and time remains to be explained.