Should we screen patients for extended-spectrum beta-lactamase-producing enterobacteriaceae in intensive care units?

Risk Factors for Colonization With Multidrug-Resistant Bacteria Among Patients Admitted to the Intensive Care Unit After Returning From Abroad

BACKGROUND

Few national recommendations exist on management of patients returning from abroad and all focus on hospitalized patients. Our purpose was to compare, in an intensive care unit (ICU), the admission prevalence and acquisition of multidrug-resistant (MDR) bacteria carriage in patients with ("Abroad") or without ("Local") a recent stay abroad, and then identify the risk factors in "Abroad" patients.

METHODS

In this retrospective study, we reviewed charts of all the patients hospitalized in the ICU unit from January 2011 through July 2013 with hygiene samplings performed. We identified all patients who had stayed abroad ("Abroad") within 6 months prior to ICU admission.

RESULTS

Of 1,842 ICU patients, 129 (7%) "Abroad" patients were reported. In the "Abroad" group, the rate of MDR strain carriage was higher at admission (33% vs 6.7%, p < 0.001) and also more often diagnosed during the ICU stay (acquisition rate: 17% vs 5.2%, p < 0.001) than in "Local" patients. Risk factors associated with MDR bacteria carriage at admission in "Abroad" patients were diabetes mellitus [odds ratio (OR) 5.1 (1.7-14.8), p = 0.003] and "hospitalization abroad with antibiotic treatment" [OR 10.7 (4.2-27.3), p < 0.001]. Hospitalization abroad without antibiotic treatment was not identified as a risk factor.

CONCLUSIONS

The main factor associated with MDR bacteria carriage after a stay abroad seems to be a hospitalization abroad only in case of antibiotic treatment abroad. Screening and isolation of "Abroad" patients should be recommended, even in case of a first negative screening.

Targeted screening for third-generation cephalosporin-resistant Enterobacteriaceae carriage among patients admitted to intensive care units: a quasi-experimental study

Introduction

Identification of third-generation, cephalosporin-resistant Enterobacteriaceae (3GC-RE) carriers by rectal screening at admission seems to be an important step in the prevention of transmission and outbreaks; however, little is known about its effectiveness. The aim of this study was to evaluate the impact of ‘targeted screening’ at patient admission to intensive care units (ICUs) on the incidence of 3GC-RE hospital-acquired infections (HAIs) and compare it to ‘universal screening’.

Methods

We undertook a quasi-experimental study of two ICUs (unit A: intervention group; unit B: control group) at a university-affiliated hospital between 1 January 2008 and 31 December 2011. In unit A, patients were screened universally for 3GC-RE at admission during period 1 (1 January 2008 through 30 September 2010). During period 2 (2011 calendar year), the intervention was implemented in unit A; patients transferred from another unit or hospital were screened selectively. In unit B, all patients were screened throughout periods 1 and 2. 3GC-RE-related HAI incidence rates were expressed per 1,000 patient-days. Incidence rate ratios (IRRs) were examined by multivariate Poisson regression modelling.

Results

In unit A, 3GC-RE-related HAI incidence rates decreased from 5.4 (95% confidence interval (CI), 4.1 to 7.0) during period 1 to 1.3 (95% CI, 0.5 to 2.9) during period 2 (P < 0.001). No changes were observed in unit B between periods 1 and 2 (P = 0.5). In unit A, the adjusted incidence of 3GC-RE-related HAIs decreased in period 2 compared with period 1 (adjusted IRR, 0.3; 95% CI, 0.1 to 0.9; P = 0.03) independently of temporal trend, trauma and age. No changes were seen in unit B (P = 0.4). The total number of rectal swabs taken showed an 85% decrease in unit A between period 1 and 2 (P < 0.001).

Conclusions

Targeted screening of 3GC-RE carriers at ICU admission was not associated with an increase in 3GC-RE-related HAI incidence compared with universal screening. Total number of rectal swabs decreased significantly. These findings suggest that targeted screening may be worth assessing as an alternative to universal screening.

Fecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae in Korean community and hospital settings

PURPOSE

The assessment and early recognition of risk factors for infections due to extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) are important for infection control and proper treatment. The aim of the present study was to investigate the prevalence of fecal carriage of ESBL-E in healthy individuals and hospitalized high-risk patients in Korea and to compare the characteristics of ESBL-E in these two groups.

METHODS

A total of 384 samples from 290 healthy individuals and 94 high-risk patients were collected. The screening of ESBL-E was performed using a commercial chromogenic medium. Bacterial identification and antibiotic susceptibility testing were performed using the Vitek 2 system.

RESULTS

The prevalence of ESBL-E carriage was 20.3 % in healthy individuals and 42.5 % in high-risk patients. Escherichia coli comprised a large majority (96.6 %) of the isolates from healthy individuals, but Klebsiella pneumoniae was more commonly detected (45.0 %) in high-risk patients than in healthy individuals. K. pneumoniae isolates exhibited significantly higher resistance to ceftazidime, ampicillin, and carbapenem, and E. coli exhibited higher resistance to cefotaxime. E. coli from high-risk patients exhibited significantly higher resistance to levofloxacin and cefepime than that from healthy individuals.

CONCLUSIONS

We demonstrated the high prevalence of ESBL-E carriage in Korea and clarified the characteristics of ESBL-E carriage in healthy individuals and high-risk patients. The distribution and antibiotic susceptibility of colonizing ESBL-E were different between the group of healthy individuals and the high-risk patients. Active surveillance of ESBL-E carriage is suggested for infection control, and the use of chromogenic agar appears to be an efficient method.

Preventing the spread of multidrug-resistant gram-negative pathogens: recommendations of an expert panel of the German Society For Hygiene and Microbiology

BACKGROUND

Infections with multidrug-resistant gram-negative bacteria are hard to treat and cause high morbidity and mortality. The direct transmission of such pathogens is well documented, and measures to protect other patients would seem indicated. Nonetheless, evidence-based recommendations are not yet available because of insufficient data from clinical trials.

METHODS

An expert panel was convened by two sections of the German Society for Hygiene and Microbiology (the permanent committee on general and hospital hygiene and the special committee on infection prevention and antibiotic resistance in hospitals) to review existing data on the epidemiology and diagnostic evaluation of multidrug-resistant gram-negative pathogens. The panel carried out a selective review of the relevant literature, with special attention to national guidelines.

RESULTS AND CONCLUSION

In this paper, the expert panel presents a definition of multidrug-resistant gram-negative pathogens and recommends measures for presenting the spread of infection from colonized and infected patients in non-outbreak situations. These measures depend on the risk profile of the clinical setting. They are mostly to be considered "expert opinion," rather than "evidence-based."

Increase of patients co-colonised or co-infected with methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium or extended-spectrum β-lactamase-producing Enterobacteriaceae

PURPOSE

To determine the incidence of patients co-colonised or co-infected with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium or extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in four German tertiary care hospitals.

METHODS

This study was conducted at four tertiary care hospitals (all with >1,000 beds) in different geographic regions in Germany (Berlin in the east, Luebeck in the north, Freiburg in the southwest and Nuernberg in the southeast). Routine surveillance data on MRSA, vancomycin-resistant enterococci (VRE) and ESBL-producing bacteria were analysed from 2007 to 2009. Co-colonisation or co-infection was defined as a patient having positive cultures for at least two of the following resistant pathogens: MRSA, VRE faecium or different species of ESBL-producing Enterobacteriaceae within one calendar year.

RESULTS

A total of 896,822 patients were analysed, of which 10,066 patients harboured MRSA, VRE faecium and/or ESBL-producing Enterobacteriaceae, and 542 patients co-harboured at least two of those resistant pathogens. In 2009, 7.6% of the MRSA patients, 13.7% of the VRE faecium patients and even 16.1% of the ESBL-producing Enterobacteriaceae patients were co-colonised or co-infected. The incidence of patients with co-infection or co-colonisation increased steadily from 5 (2007) to 7 per 10,000 patients (2009).

CONCLUSIONS

Patients harbouring ESBL-producing Enterobacteriaceae or VRE faecium had a higher risk of being co-colonised or co-infected compared to what was to be extrapolated from their overall incidence. This might be linked to their gastrointestinal reservoir and impracticality to decolonise the gut of resistant VRE and ESBL-producing Enterobacteriaceae.

Wide dissemination of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella spp. in acute care and rehabilitation hospitals

A prospective surveillance system for extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E) and ESBL-producing Klebsiella spp. (ESBL-K) was implemented in 39 German hospitals with the aim of determining the incidence densities (IDs) of community-onset and hospital-onset cases and of identifying risk factors for high IDs of hospital-onset cases. During 2008, 2081 ESBL-E/K cases were documented. ESBL-E cases (n=1330, 63·9%) were more common than ESBL-K cases (n=751, 36·1%), but a higher proportion of ESBL-K cases (59%) than of ESBL-E cases (39·5%) were hospital-onset cases. The mean IDs were 0·54 (range 0–2·53) per 1000 patient-days for all ESBL-EK cases, 0·29 (range 0–1·81) per 1000 patient-days for community-onset ESBL-EK cases and 0·25 (range 0–1·82) per 1000 patient-days for hospital-onset ESBL-EK cases. Regression analysis showed a linear association between the IDs of community-onset and hospital-onset cases. The wide dissemination of ESBL-E and ESBL-K emphasizes the need for hospital-wide surveillance to guide control measures.

Dramatic increase of third-generation cephalosporin-resistant E. coli in German intensive care units: secular trends in antibiotic drug use and bacterial resistance, 2001 to 2008

Introduction

The objective of the present study was to analyse secular trends in antibiotic consumption and resistance data from a network of 53 intensive care units (ICUs).

Methods

The study involved prospective unit and laboratory-based surveillance in 53 German ICUs from 2001 through 2008. Data were calculated on the basis of proportions of nonduplicate resistant isolates, resistance densities (that is, the number of resistant isolates of a species per 1,000 patient-days) and an antimicrobial usage density (AD) expressed as daily defined doses (DDD) and normalised per 1,000 patient-days.

Results

Total mean antibiotic use remained stable over time and amounted to 1,172 DDD/1,000 patient-days (range 531 to 2,471). Carbapenem use almost doubled to an AD of 151 in 2008. Significant increases were also calculated for quinolone (AD of 163 in 2008) and third-generation and fourth-generation cephalosporin use (AD of 117 in 2008). Aminoglycoside consumption decreased substantially (AD of 86 in 2001 and 24 in 2008). Resistance proportions were as follows in 2001 and 2008, respectively: methicillin-resistant Staphylococcus aureus (MRSA) 26% and 20% (P = 0.006; trend test showed a significant decrease), vancomycin-resistant enterococcus (VRE) faecium 2.3% and 8.2% (P = 0.008), third-generation cephalosporin (3GC)-resistant Escherichia. coli 1.2% and 19.7% (P < 0.001), 3GC-resistant Klebsiella pneumoniae 3.8% and 25.5% (P < 0.001), imipenem-resistant Acinetobacter baumannii 1.1% and 4.5% (P = 0.002), and imipenem-resistant K. pneumoniae 0.4% and 1.1%. The resistance densities did not change for MRSA but increased significantly for VRE faecium and 3GC-resistant E. coli and K. pneumoniae. In 2008, the resistance density for MRSA was 3.73, 0.48 for VRE, 1.39 for 3GC-resistant E. coli and 0.82 for K. pneumoniae.

Conclusions

Although total antibiotic use did not change over time in German ICUs, carbapenem use doubled. This is probably due to the rise in 3GC-resistant E. coli and K. pneumoniae. Increased carbapenem consumption was associated with carbapenem-resistant K. pneumoniae carbapenemase-producing bacteria and imipenem-resistant A. baumannii.

Evaluation of Brilliance ESBL agar, a novel chromogenic medium for detection of extended-spectrum-beta- lactamase-producing Enterobacteriaceae

The aim of this study was to evaluate the performance of Brilliance ESBL agar (OX; Oxoid, Basingstoke, United Kingdom), a novel chromogenic agar for the selective isolation and the presumptive identification of extended-spectrum-beta-lactamase (ESBL)-producing Enterobacteriaceae. A panel of 200 clinical Gram-negative Enterobacteriaceae and nonfermenting isolates with defined resistance mechanisms was inoculated onto OX and onto ChromID ESBL agar (BM; bioMérieux, Marcy l'Etoile, France) chromogenic medium in the first part of the study to evaluate the growth selectivity and chromogenic features of these two media. Of the 156 Enterobacteriaceae challenge isolates, 8 fully susceptible isolates were inhibited, all 98 ESBL producers were detected, and 50 isolates harboring other resistance mechanisms were recovered on both chromogenic agars. In the second phase, 528 clinical samples (including 344 fecal specimens) were plated onto OX, BM, and MacConkey agar with a ceftazidime disk (MCC) for the screening of ESBL-producing Enterobacteriaceae. Growth on at least one medium was observed with 144 (27%) of the clinical samples screened. A total of 182 isolates, including 109 (60%) of Enterobacteriaceae, were recovered and 70 of these (from 59 specimens) were confirmed as ESBL-producing isolates. The sensitivities of MCC, BM, and OX were 74.6%, 94.9%, and 94.9%, respectively. The specificities of MCC, BM, and OX by specimens reached 94.9%, 95.5%, and 95.7%, respectively, when only colored colonies were considered on the two selective chromogenic media. The high negative predictive value (99.3%) found for OX suggests that this medium may constitute an excellent screening tool for the rapid exclusion of patients not carrying ESBL producers.

Extended-spectrum beta-lactamase-producing Enterobacter cloacae in mobile dialysis units in the medical and surgical departments of a university hospital: a case-control study

The objective of this case-control study was to investigate the source of contamination and risk factors for colonisation and infection during an outbreak of extended-spectrum beta-lactamase (ESBL)-producing Enterobacter cloacae in the University Medical Center Freiburg. A risk factor analysis was performed on 23 patients with ESBL-producing E. cloacae in the medical and surgical departments by comparing them with 46 non-colonised controls, who were matched for ward and length of hospital stay. For these, a risk factor analysis was conducted. Suspected sources for transmission of ESBL were examined and staff received training in infection control measures. The higher risk in colonised patients was attributed to dialysis with mobile units [odds ratio (OR): 4.00; 95% confidence interval (CI): 1.05-15.234; P=0.04]. Dialysis units were examined, but no contamination was found. Improvement in dialysis procedures, additional staff training and renewed training in standard precautions led to a substantial fall in case numbers. Risk factor analysis showed that colonised patients carried more invasive devices than controls (central venous catheter: OR: 2.50; 95% CI: 0.74-8.45; P=0.14; Foley catheter: 5.08; 0.61-42.23; P=0.13) and were given a greater number of different antibiotics (penicillins: 2.52; 0.71-8.89; P=0.15; fluoroquinolones: 2.37; 0.77-7.28; P=0.13). The differences in mobile dialysis frequency and antibiotic use between cases and controls were relevant, although the latter was not statistically significant. It was possible to contain the high frequency of ESBL colonisation or infection by reinforcing infection control measures and training the staff involved.