Israeli National Policy for Carbapenem-Resistant Enterobacteriaceae Screening, Carrier Isolation and Discontinuation of Isolation

How effective are monthly departmental tracer surveys? A 5-year retrospective study of 138 surveys in 96 departments

BACKGROUND

Repeat department-wide surveys are commonly employed for infection control. There remains debate concerning their cost-effectivess. The aim of the study was to measure the impact of repeat department-wide surveys in major in-patient departments (IPDs) and ambulatory facilities (AFs) in a tertiary care hospital. This was a retrospective study of 138 surveys condcuted in 96 departments over a 5-year period.

METHODS

Two itemized questionnaires were designed to assess the most frequently inadequately adhered to infection control measures: one for IPD (with 21 items) and the other for AF (with 17 items).

RESULTS

A total of 72 surveys were conducted in 49 IPDs, of which 39 (54%) were repeat surveys, and 66 surveys in 47 AFs, of which 33 (50%) were repeat surveys. The baseline rate of adherence/department was 71% ± 14 for the IPD, with an increase from the first to the last survey to 82% ± 13 (P = .037). In 15/21 measured infection control items, adherence improved. Adherence to infection control items was lower at baseline in the AFs than in the IPDs (63 ± 27), with an increase to 76 ± 20 (non significant). Although adherence improved for 9 items, it deteriorated in another 8, producing an overall statistically unchanged outcome.

CONCLUSION

Repeat whole-department surveys contribute moderately to increased adherence to infection control guidelines. AFs demonstrate lower rates of adherence to infection control guidelines and are less receptive to educational measures.

The Natural History of Carbapenemase-Producing Enterobacterales: Progression From Carriage of Various Carbapenemases to Bloodstream Infection

BACKGROUND

Little is known about the risk of progression from carbapenemase-producing Enterobacterales (CPE) carriage to CPE bloodstream infection (BSI) outside of high-risk settings. We aimed to determine the incidence of CPE BSI among CPE carriers and to assess whether the incidence differs by carbapenemase, species, and setting.

METHODS

We conducted a nationwide population-based retrospective cohort study using national databases. The cohort consisted of all patients in Israel with CPE detected by screening from 1 January 2020 to 10 October 2022. We calculated the cumulative incidence of CPE BSI within 1 year among CPE carriers. We used a competing-risks model with BSI as the outcome and death as the competing risk.

RESULTS

The study included 6828 CPE carriers. The cumulative incidence of CPE BSI was 2.4% (95% confidence interval [CI], 2.1-2.8). Compared with Klebsiella pneumoniae carbapenemase (KPC), the subhazard of BSI was lower for New Delhi metallo-β-lactamase (NDM) (adjusted subhazard ratio [aSHR], 0.72; 95% CI, .49-1.05) and oxacillinase-48-like (OXA-48-like) (aSHR, 0.60; 95% CI, .32-1.12) but these differences did not reach statistical significance. Compared with K. pneumoniae, the subhazard of BSI was lower for carriers of carbapenemase-producing Escherichia coli (aSHR, 0.33; 95% CI, .21-.52). The subhazard of BSI was higher among patients with CPE carriage first detected in intensive care units (aSHR, 2.10; 95% CI, 1.27-3.49) or oncology/hematology wards (aSHR, 3.95; 95% CI, 2.51-6.22) compared with medical wards.

CONCLUSIONS

The risk of CPE BSI among CPE carriers is lower than previously reported in studies that focused on high-risk patients and settings. The risk of BSI differs significantly by bacterial species and setting, but not by carbapenemase.

A predictive score for the result of carbapenem-resistant Enterobacterales and vancomycin-resistant enterococci screening

BACKGROUND

The duration of extensively drug-resistant bacteria (XDR) carriage depends on several factors for which the information can be difficult to recover.

AIM

To determine whether past screening and clinical results of patients can predict the results of subsequent screening.

METHODS

In total, 256 patients were retrospectively included from 10 healthcare centres in France from January 2014 to January 2022. We created a predictive clearance score, ranging from -5 to +7, that included the number of XDR species and the type of resistance detected in the sample, as well as the time from the last positive sample, the number of previous consecutive negative samples, and obtaining at least one negative PCR result in the collection. This score could be used for the upcoming rectal screening of a patient carrying an XDR as soon as the last screening sample was negative.

FINDINGS

The negative predictive value was >99% for score ≤0. The median time to achieve XDR clearance was significantly shorter for a score of 0 (443 days (259-705)) than that based on previously published criteria.

CONCLUSION

This predictive score shows high performance for the assessment of XDR clearance. Relative to previous guidelines, it could help to lift specific infection prevention and control measures earlier. Nevertheless, the decision should be made according to other factors, such as antimicrobial use and adherence to hand hygiene.

Comparison of clinical outcomes of patients with serial negative surveillance cultures according to a subsequent polymerase chain reaction test for carbapenemase-producing Enterobacterales

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) are of serious concern worldwide due to high morbidity and mortality.

AIM

To evaluate the impact of the result of a subsequent polymerase chain reaction (PCR) test for carbapenemase after serial negative surveillance cultures on positive culture conversion in patients with three consecutive negative surveillance cultures for CPE, and to identify risk factors for conversion.

METHODS

A retrospective study of patients with positive CPE cultures on CHROMagar KPC medium was performed in a Korean tertiary hospital from October 2018 to December 2022. PCR for blaKPC, blaNDM, blaIMP, blaVIM, blaGES, and blaOXA-48 was performed after three consecutive negative rectal swab cultures. Clinical characteristics and outcomes of patients were compared according to whether follow-up PCR was positive (CNPP) or negative (CNPN).

FINDINGS

Of 1075 patients with positive CPE cultures, 150 (14.0%) yielded three consecutive negative rectal swab cultures. Of these, 50 (33.3%) were CNPP, and 100 (66.7%) were CNPN. Risk factors associated with a positive PCR result on multivariate analysis were: age, central venous catheter, and Escherichia coli infection. CNPP patients were more likely to have positive culture conversion for CPE than CNPN patients (39/44 (88.6%) vs 21/50 (42.0%), P<0.001). In multivariate analysis, independent risk factors for culture conversion were: a positive PCR result after surveillance cultures, diabetes mellitus, central venous catheter, and Klebsiella pneumoniae.

CONCLUSION

CNPP patients have higher rates of culture conversion than CNPN patients, and a follow-up PCR test after serial negative surveillance cultures is useful in deciding whether or not to discontinue contact precautions.

Plasmid-encoded VCC-1 β-lactamase in a clinical isolate of Aeromonas caviae

Vibrio cholerae carbapenemase (VCC-1) is a chromosomal encoded class A carbapenemase thus far reported in environmental Vibrio cholerae isolates. Here, we report the first isolation of a blaVCC-1 -carrying Aeromonas caviae from a clinical sample in Israel. The isolate was resistant to all β-lactam agents, including carbapenems. The blaVCC-1 was located on a large plasmid. GC content suggests that the origin of the blaVCC-1 gene is neither Aeromonas nor Vibrio spp. but an unknown progenitor.

Epidemiological characteristics of carbapenemase-producing Enterobacteriaceae outbreaks in the Republic of Korea between 2017 and 2022

BACKGROUND

We aimed to describe the epidemiological characteristics of carbapenemase-producing Enterobacteriaceae (CPE) outbreaks in healthcare settings in the Republic of Korea between 2017 and 2022.

METHODS

Under the national notifiable disease surveillance system, we obtained annual descriptive statistics regarding the isolated species, carbapenemase genotype, healthcare facility type, outbreak location and duration, and number of patients affected and recommended interventions. We used epidemiological investigation reports on CPE outbreaks reported to Korea Disease Control and Prevention Agency from June 2017 to September 2022.

RESULTS

Among the 168 reports analyzed, Klebsiella pneumoniae (85.1%) was the most frequently reported species, while K. pneumoniae carbapenemase (KPC, 82.7%) was the most common carbapenemase genotype. Both categories increased from 2017 to 2022 (p<0.01). General hospitals had the highest proportion (54.8%), while tertiary general hospitals demonstrated a decreasing trend (p<0.01). The largest proportion of outbreaks occurred exclusively in intensive care units (ICUs, 44.0%), and the frequency of concurrent outbreaks in ICUs and general wards increased over time (p<0.01). The median outbreak duration rose from 43.5 days before the coronavirus disease 2019 (COVID-19) pandemic (2017-2019) to 79.5 days during the pandemic (2020-2022) (p=0.01), and the median number of patients associated with each outbreak increased from 5.0 to 6.0 (p=0.03). Frequently recommended interventions included employee education (38.1%), and 3 or more measures were proposed for 45.2% of outbreaks.

CONCLUSION

In the Republic of Korea, CPE outbreaks have been consistently dominated by K. pneumoniae and KPC. The size of these outbreaks increased during the COVID-19 pandemic. Our findings highlight the need for continuing efforts to control CPE outbreaks using a multimodal approach, while considering their epidemiology.

The impact of enhanced screening for carbapenemase-producing Enterobacterales in an acute care hospital in South Korea

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) poses a significant challenge to infection control in healthcare settings. Active screening is recommended to prevent intra-hospital CPE transmission.

METHODS

CPE screening was initiated at a 660-bed hospital in South Korea in September 2018, targeting patients previously colonized/infected or admitted to outside healthcare facilities (HCFs) within 1 month. Universal intensive care unit (ICU) screening was performed at the time of admission. After a hospital-wide CPE outbreak in July-September 2019, the screening program was enhanced by extending the indications (admission to any HCF within 6 months, receipt of hemodialysis) with weekly screening of ICU patients. The initial screening method was changed from screening cultures to the Xpert Carba-R assay. The impact was assessed by comparing the CPE incidence per 1000 admissions before (phase 1, September 2018-August 2019) and after instituting the enhanced screening program (phase 2, September 2019-December 2020).

RESULTS

A total of 13,962 (2,149 and 11,813 in each phase) were screened as indicated, among 49,490 inpatients, and monthly screening compliance increased from 18.3 to 93.5%. Compared to phase 1, the incidence of screening positive patients increased from 1.2 to 2.3 per 1,000 admissions (P = 0.005) during phase 2. The incidence of newly detected CPE patients was similar (3.1 vs. 3.4, P = 0.613) between two phases, but the incidence of hospital-onset CPE patients decreased (1.9 vs. 1.1, P = 0.018). A significant decrease was observed (0.5 to 0.1, P = 0.014) in the incidence of patients who first confirmed CPE positive through clinical cultures without a preceding positive screening. Compared to phase 1, the median exposure duration and number of CPE contacts were also markedly reduced in phase 2: 10.8 days vs. 1 day (P < 0.001) and 11 contacts vs. 1 contact (P < 0.001), respectively. During phase 2, 42 additional patients were identified by extending the admission screening indications (n = 30) and weekly in-ICU screening (n = 12).

CONCLUSIONS

The enhanced screening program enabled us to identify previously unrecognized CPE patients in a rapid manner and curtailed a hospital-wide CPE outbreak. As CPE prevalence increases, risk factors for CPE colonization can broaden, and hospital prevention strategies should be tailored to the changing local CPE epidemiology.

Clinical and molecular features of NDM-producing Acinetobacter baumannii in a multicenter study in Israel

BACKGROUND

NDM-producing Acinetobacter baumannii (NDMAb) were reported sporadically worldwide but little is known about the transmission, epidemiology and clinical features of NDMAb-infected patients. The goals of this study were to characterize (1) the epidemiology and clinical features of NDMAb-infected patients; (2) the microbiological and molecular features of NDMAb isolates and (3) the transmission networks of NDMAb within healthcare facilities.

METHODS

The study was conducted at the Tel-Aviv Sourasky, Rambam and Sha'are-Zedek Medical centers (TASMC, RMC and SZMC, respectively) in Israel. All cases detected between January 2018 and July 2019 were included. Phylogenetic analysis was based on core genome SNP distances. Clonal transmission was defined according to molecular (≤ 5 SNP) and epidemiological criteria (overlapping hospital stay). NDMAb cases were compared at a ratio of 1:2 with non-NDM carbapenem-resistant A. baumannii (CRAb) cases.

RESULTS

The study included 54 NDMAb-positive out of 857 CRAb patients, including 6/179 (3.3%) in TASMC, 18/441 (4.0%) in SZMC and 30/237 (12.6%) in RMC. Patients infected by NDMAb had similar clinical features and risk factors as patients with non-NDM CRAb. The length-of-stay was higher in NDMAb cases (48.5 days vs. 36 days, respectively, p = 0.097) and the in-hospital mortality was similarly high in both groups. Most isolates (41/54, 76%) were first detected from surveillance culture. The majority of isolates harbored the bla_{NDM-2 gene} allele (n = 33), followed by the bla_NDM-1 (n = 20) allele and the bla_NDM-4 allele (n = 1). The majority of isolates were related within the ST level to other isolates in SZMC and RMC: 17/18 and 27/30 isolates, respectfully. The common ST's were the bla_NDM-1 harboring ST-2 (n = 3) and ST-107 (n = 8) in SZMC and the bla_NDM-2 harboring ST-103 in SZMC (n = 6) and in RMC (n = 27). All bla_NDM alleles were located within a conserved mobile genetic environment flanked by the ISAb125 and IS91 family transposon. Clonal transmission was identified in most hospital-acquired cases in RMC and SZMC.

CONCLUSION

NDMAb constitutes a minor part of CRAb cases and are clinically similar to non-NDM CRAb. Transmission of NDMAb occurs mostly by clonal spread.

Molecular features and transmission of NDM-producing Enterobacterales in Israeli hospitals

OBJECTIVES

NDM-producing Enterobacterales (NDME) account for 34.9% of new carbapenemase-producing Enterobacterales cases in Israeli hospitals. The goals of this study were to characterize the genomic composition of NDME isolates and mobile genetic elements (MGEs) and to identify NDME transmission events (TEs).

METHODS

The study was conducted at the Tel-Aviv Sourasky, Rambam and Sha'are-Zedek Medical Centers (TASMC, RMC and SZMC, respectively). All NDME isolates detected between January 2018 and July 2019 were included.Phylogenetic analysis was based on core-genome SNP distances. Core-genome distance of ≤5 SNPs between isolates from patients with overlapping hospitalization periods was suggestive of a potential TE. MGEs were classified by comparison of the blaNDM gene flanking regions.

RESULTS

The study included 212 NDME isolates from 203 patients, including 104 isolates from TASMC, 30 isolates from RMC and 78 isolates from SZMC. The majority of isolates (n = 157; 74%) harboured the blaNDM-1 gene, followed by the blaNDM-5 (n = 48) and blaNDM-15 genes (n = 7). The most common NDME species were Klebsiella pneumoniae (n = 67), Escherichia coli (n = 65) and Enterobacter cloacae (n = 45), all showing a highly diverse clonal structure. Most blaNDM-1-harbouring isolates (134/157; 85%) were divided into nine different MGE modules, variably distributed across species and hospitals.The numbers of post-admission acquisition cases (n = 118) that could be linked to other cases by both molecular and epidemiological criteria were 13/58 (24.2%), 3/48 (6.3%) and 4/12 (33.3%) in TASMC, SZMC and RMC, respectively.

CONCLUSIONS

The study depicted a complex and diverse population structure, suggesting that NDME had not spread via clonal expansion.

Clinical and molecular characteristics and risk factors for patients acquiring carbapenemase-producing and non-carbapenemase-producing carbapenem-nonsusceptible-Enterobacterales bacteremia

BACKGROUND/PURPOSE

Carbapenem-nonsusceptible Enterobacterales (CNSE) are a growing global threat. Carbapenemases are often produced by plasmids, which allow rapid transmission. This study aimed to investigate (1) the bacterial type (2) resistant genes (3) antimicrobial susceptibility and (4) risk factors for acquisition of carbapenemase-producing carbapenem-nonsusceptible Enterobacterales (CP-CNSE) and non-carbapenemase-producing carbapenem-nonsusceptible Enterobacterales (non-CP-CNSE) bacteremia.

METHODS

There were a total of 113 isolates of Enterobacterales from 2013 to 2018. After excluding nonblood isolates and including only one sample from each patient, 99 isolates were analyzed and the medical charts of these patients were reviewed. Carbapenemase genes, β-lactamase genes and antimicrobial susceptibility of the isolates were determined. Multilocus sequence typing (MLST) was performed on CP-CNSE isolates.

RESULTS

CP-CNSE carried more bla_SHV (P = 0.004) and were more resistant to imipenem than non-CP-CNSE (P < 0.001). In the univariate analyses, we found that CP-CNSE bloodstream infection was associated with patient <65 years of age (odds ratio, 3.90; 95% confidence interval [CI], 1.16 to 13.10; P = 0.027), mechanical ventilation at the time of bloodstream infection (BSI) (odds ratio, 3.85; 95% CI, 1.16-12.78; P = 0.028) and exposure to piperacillin/tazobactam (odds ratio, 3.96; 95% CI, 1.09-14.38; P = 0.037). However, on multivariate analyses, no independent predictor for CP-CNSE was identified in this study.

CONCLUSION

CP-CNSE carried more bla_SHV and were more resistant to imipenem when compared to non-CP-CNSE. No independent predictor for CP-CNSE was identified after multivariate analysis. This is the first study conducted in Taiwan comparing risk factors between CP-CNSE and non-CP-CNSE from both clinical and molecular aspects.

Unraveling the Diversity of Co-Colonization by CPE

Antibiotic-resistant bacteria, and more specifically, carbapenem-producing Enterobacterales (CPE) strains, are increasing worldwide. Despite their growing prevalence, in most high-income countries, the detection of CPE is still considered a low-frequency event. Sporadically, patients co-colonized with distinct CPE strains and/or different carbapenemase enzymes are detected. In this paper, we present three cases that illustrate the underlying mechanisms of co-colonization, focusing on horizontal gene transfer (HGT) and patient-to-patient transmission. We also demonstrate the diversity of CPE species and discuss the potential consequences of co-colonization.

A Nomogram With Six Variables Is Useful to Predict the Risk of Acquiring Carbapenem-Resistant Microorganism Infection in ICU Patients

Background

Carbapenem-resistant microorganism (CRO) transmission in the medical setting confers a global threat to public health. However, there is no established risk prediction model for infection due to CRO in ICU patients. This study aimed to develop a nomogram to predict the risk of acquiring CRO infection in patients with the first ICU admission and to determine the length of ICU stay (ICU-LOS) and 28-day survival.

Methods

Patient data were retrieved from the Medical Information Mart for Intensive Care (MIMIC-IV) database based on predetermined inclusion and exclusion criteria. A CRO was defined as a bacterium isolated from any humoral microbial culture that showed insensitivity or resistance to carbapenems. The characteristics of CRO and non-CRO patients in the first ICU admission were compared. Propensity score matching was applied to balance the differences between the CRO and non-CRO cohorts. Kaplan–Meier curves were constructed to determine the 28-day survival rate and ICU-LOS. Furthermore, after randomization of the CRO cohort into the training and validation sets, a predictive nomogram was constructed based on LASSO regression and Logistic regression analysis, and its performance was verified by internal validation.

Results

Overall, 4531 patients who had first ICU admission as recorded in MIMIC-IV were enrolled, 183 (4.04%) of whom were diagnosed with CRO infection. Moreover, CRO infection was independently associated with 28-day survival and ICU-LOS in ICU patients. Parameters eligible for inclusion in this nomogram were male sex, hemoglobin-min, temperature-max, use of a peripherally inserted central catheter line, dialysis treatment, and use of carbapenems. This nomogram showed a better performance as indicated by the area under the receiver operating characteristic curve values of 0.776 (95% confidence interval [CI] 0.667-0.750) and 0.723 (95% CI 0.556-0.855) in the training and validation sets, respectively, in terms of predicting the risk of acquiring CRO infection.

Conclusions

CRO infection was independently associated with ICU-LOS and 28-day survival in patients with first ICU admission. The nomogram showed the best prediction of the risk of acquiring CRO infection in ICU patients. Based on the nomogram-based scoring, we can management the risk factors and guide individualized prevention and control of CRO.

Search and Contain: Impact of an Integrated Genomic and Epidemiological Surveillance and Response Program for Control of Carbapenemase-producing Enterobacterales

BACKGROUND

Multiresistant organisms (MROs) pose a critical threat to public health. Population-based programs for control of MROs such as carbapenemase-producing Enterobacterales (CPE) have emerged and evaluation is needed. We assessed the feasibility and impact of a statewide CPE surveillance and response program deployed across Victoria, Australia (population 6.5 million).

METHODS

A prospective multimodal intervention including active screening, carrier isolation, centralized case investigation, and comparative pathogen genomics was implemented. We analyzed trends in CPE incidence and clinical presentation, risk factors, and local transmission over the program's first 3 years (2016-2018).

RESULTS

CPE case ascertainment increased over the study period to 1.42 cases/100 000 population, linked to increased screening without a concomitant rise in active clinical infections (0.45-0.60 infections/100 000 population, P = .640). KPC-2 infection decreased from 0.29 infections/100 000 population prior to intervention to 0.03 infections/100 000 population in 2018 (P = .003). Comprehensive case investigation identified instances of overseas community acquisition. Median time between isolate referral and genomic and epidemiological assessment for local transmission was 11 days (IQR, 9-14). Prospective surveillance identified numerous small transmission networks (median, 2; range, 1-19 cases), predominantly IMP and KPC, with median pairwise distance of 8 (IQR, 4-13) single nucleotide polymorphisms; low diversity between clusters of the same sequence type suggested genomic cluster definitions alone are insufficient for targeted response.

CONCLUSIONS

We demonstrate the value of centralized CPE control programs to increase case ascertainment, resolve risk factors, and identify local transmission through prospective genomic and epidemiological surveillance; methodologies are transferable to low-prevalence settings and MROs globally.

A hospital-wide outbreak of IMI-17-producing Enterobacter ludwigii in an Israeli hospital

Background

To describe the course and intervention of an hospital-wide IMI-Producing Enterobacter ludwigii outbreak.

Methods

This was an outbreak interventional study, done at a tertiary care center in Tel-Aviv, Israel. Data was collected on the course of the outbreak and the demographic and clinical characteristics of all patients involved in the outbreak. The intervention measures included patients’ cohorting, contact isolation precautions, environmental cleaning and screening of contacts. The molecular features and phylogeny of outbreak-related isolates were studied by whole-genome based analysis.

Results

The outbreak included 34 patients that were colonized by IMI-Producing E. ludwigii and were identified in 24 wards throughout the hospital. Colonization was identified in the first 72 h of admission in 13/34 patients (38.2%). Most patients (91.2%) were admitted from home and had relatively low level of comorbidities. The majority of them (88%) had no recent use of invasive catheters and none had previous carriage of other multi-drug resistant bacteria. All available isolates harbored the bla_IMI-17 allele and belonged to Sequence-Type 385. With the exception of two isolates, all isolates were closely related with less than a 20-SNP difference between them.

Conclusions

This outbreak had most likely originated in the community and subsequently disseminated inside our institution. More studies are required in order to elucidate the epidemiology of IMI-Producing E. ludwigii and the possible role of environmental sources in its dissemination.

Multidrug-Resistant Gram-Negative Bacteria: Infection Prevention and Control Update

Multidrug-resistant gram-negative bacteria (MDR-GNB) pose one of the greatest challenges to health care today because of their propensity for human-to-human transmission and lack of therapeutic options. Containing the spread of MDR-GNB is challenging, and the application of multifaceted infection control bundles during an evolving outbreak makes it difficult to measure the relative impact of each measure. This article will review the utility of various infection control measures in containing the spread of various MDR-GNB and will provide the supporting evidence for these interventions.

Bacterial characteristics of carbapenem-resistant Enterobacteriaceae (CRE) colonized strains and their correlation with subsequent infection

BACKGROUND

Searching the risk factors for carbapenem-resistant Enterobacteriaceae (CRE) infection is important in clinical practice. In the present study, we aim to investigate bacterial characteristics of colonizing strains and their correlation with subsequent CRE infection.

METHODS

Between May 2018 and January 2019, patients hospitalized in the department of haematology and intensive care unit (ICU) were screened for CRE by rectal swabs and monitored for the outcome of infection. We identified the species and carbapenemase-encoding genes of colonizing strains and performed antimicrobial susceptibility tests and multilocus sequence typing (MLST). Risk factors for subsequent CRE infections were ascertained by univariate and multivariable analysis.

RESULTS

We collected a total of 219 colonizing strains from 153 patients. Klebsiella pneumoniae was the most abundant species, and MLST analysis showed rich diversity. K. pneumoniae carbapenemase (KPC) was predominant in the infection group (72.4%). In the non-infection group, 35.4% of strains were non-carbapenemase-producing CRE (NCP-CRE), and New Delhi metallo-β-lactamase (NDM) was predominant (42.2%). The rate of high-level carbapenem resistance (minimum inhibitory concentration [MIC] ≥ 64 mg/L for meropenem and ertapenem, ≥ 32 mg/L for imipenem) was remarkably higher in the infection group than in the non-infection group (P <  0.001). Univariate analysis showed that K. pneumoniae, high-level carbapenem resistance, CP-CRE and KPC-CRE were infection risk factors after CRE colonization. On multivariable analysis with different carbapenemase dichotomizations, KPC-CRE (adjusted odds ratio [aOR], 4.507; 95% confidence interval [CI], 1.339-15.171; P = 0.015) or imipenem MIC ≥ 32 mg/L (aOR, 9.515; 95% CI, 1.617-55.977; P = 0.013) were respectively identified as independent risk factors for subsequent infection.

CONCLUSIONS

Patients colonized with KPC-CRE or strains with an imipenem MIC ≥ 32 mg/L were at particularly high risk of subsequent CRE infections during their hospital stay.

Combined selective culture and molecular methods for the detection of carbapenem-resistant organisms from fecal specimens

Detection of patients with intestinal colonization of carbapenem-resistant organisms (CRO), or more specifically carbapenemase-producing (CP) CRO, can prevent their transmission in healthcare facilities and aid with outbreak investigations. The objective of this work was to further develop and compare methods that combine selective culture and/or PCR to rapidly detect and recover CRO from fecal specimens. Molecularly characterized Gram-negative bacilli (n = 62) were used to spike fecal samples to establish limit of detection (LOD; n = 12), sensitivity (n = 28), and specificity (n= 21) for 3 methods to detect CP-CRO: direct MacConkey (MAC) plate and Xpert Carba-R (Cepheid) on growth, MAC broth and Carba-R testing of the broth, and direct testing by Carba-R. This was followed by a clinical study comparing methods in parallel for 286 fecal specimens. The LOD ranged from 10^2-10⁵ CFU/mL depending on the carbapenemase gene and method. Combined culture/PCR methods had a sensitivity of 100%, whereas direct Carba-R testing had a sensitivity of 96% for the detection of CP-CRO. All methods had specificities of 100%. The prevalence of CP-CRO (0.7%) and non-CP-CRO (5.2 %) were low in the clinical study, where all methods demonstrated 100% agreement. The three methods performed comparably in detecting CP-CRO. Direct Carba-R testing had a higher LOD than the combined selective culture methods, but this may be offset by its rapid turnaround time for detection of CP-CRO. The selective culture methods provide the benefit of simultaneously isolating CP-CRO in culture for follow-up testing and detecting non-CP-CRO.

Clinical and epidemiological features of patients colonised by different types of carbapenemase-producing Enterobacterales

OBJECTIVES

The aim of this study was to compare the epidemiological and clinical characteristics of hospitalised patients colonised or infected by different types of carbapenemase-producing Enterobacterales (CPE) and to analyse the differences in their outcome.

METHODS

This was a retrospective comparative study of all patients colonised or infected by KPC-, NDM- or OXA-48-producing CPE who were hospitalised between 1 January 2018 and 30 June 2019. Microbiological, demographic and clinical data were collected from the patients' computerised files.

RESULTS

One type of CPE was isolated in 285 patients, including 138 with KPC-CPE, 94 with NDM-CPE and 53 with OXA-48-CPE. The most common CPE types were KPC-Klebsiella pneumoniae (n = 47), OXA-48-Escherichia coli (n = 38), NDM-Enterobacter cloacae complex (n = 35) and KPC-Citrobacter freundii (n = 37). All three groups of patients were similar with respect to their risk factors, with the exception of previous exposure to antimicrobials that was more common in patients with KPC-CPE compared with OXA-48-CPE. Also, these patients were more likely to be co-infected by other multidrug-resistant bacteria. Clinical infections were more common in KPC-CPE than in OXA-48-CPE carriers (9.9% vs. 1.9%; P = 0.033). No other demographic or clinical variables were found to be correlated with clinical infections.

CONCLUSION

Our study suggests that colonisation by OXA-48-CPE might be less risky compared with KPC-CPE.

The Israeli national policy for discontinuation of isolation of carbapenem-resistant Enterobacterales carriers by carbapenemase type: a retrospective cohort study

OBJECTIVES

The Israeli national policy for containing carbapenemase-producing Enterobacterales (CPE) includes a protocol allowing for discontinuation of carrier status following spontaneous decolonization. We examined the strategy's effectiveness based on carbapenemase type.

METHODS

We performed a retrospective cohort study comparing individuals colonized with KPC- or NDM-producing Enterobacterales who underwent the process of isolation discontinuation. The primary outcome was reversion of carrier status, i.e. re-identification of the same CPE species following isolation discontinuation. We used survival analysis to estimate overall hazard ratio and performed competing-risks analysis using a Fine-Gray subdistribution hazard model and cause-specific hazard ratios.

RESULTS

Between 1 January 2006 and 1 January 2019 we identified 1694 individuals who met inclusion criteria, including 1337 (78.9%) carriers of KPC-producing Enterobacterales, 305 (18.0%) carriers of NDM-producing Enterobacterales and 52 (3.1%) carriers of dual KPC-/NDM-producing Enterobacterales. A total of 134 individuals (7.9%) had reversion of carrier status: 9.1% (121/1337) and 4.3% (13/305) of individuals with KPC- and NDM-producing Enterobacterales, respectively. The subdistribution hazard ratio of status reversion was not increased among carriers of NDM producers compared with KPC producers (0.567, 95% CI 0.320-1.000], p 0.052). Cause-specific hazard ratios yielded similar results (0.522, 95% CI 0.291-0.937, p 0.029.

CONCLUSIONS

Carriage of NDM-producing Enterobacterales was not associated with higher rates of reversion to carrier status following spontaneous decolonization than was carriage of KPC-producing Enterobacterales.

National Policy for Carbapenem-Resistant Enterobacteriaceae (CRE) Clearance and Discontinuation of Contact Precautions for CRE Carriers in Post-Acute Care Hospitals in Israel: Impact on Isolation-Days and New Acquisitions

BACKGROUND

In 2009, the Israeli Ministry of Health implemented in post-acute care hospitals (PACHs) a process of discontinuing carbapenem-resistant Enterobacteriaceae (CRE) carrier status. We evaluated the policy's impact on isolation-days, CRE prevalence among known carriers who had completed clearance testing, and CRE acquisition among noncarriers.

METHODS

This retrospective study summarized findings from all 15 PACHs in 2009-2017. CRE carriers were considered cleared and removed from contact isolation after 2 rectal cultures negative for CRE and polymerase chain reaction negative for carbapenemases. Data sources included routine surveillance and 4 point prevalence surveys conducted from 2011 to 2017.

RESULTS

During the study period, 887 of 6101 CRE carriers (14.5%) completed clearance testing. From 2013 to 2016, the percentage of patient-days in CRE isolation decreased from 9.4% to 3.9% (P = .008). In all surveys combined, there were 819 known CRE carriers; 411 (50%) had completed clearance testing. Of these, 11.4% (47/411) were CRE positive in the survey. At the ward level, the median percentage of patients with no CRE history who were positive on survey decreased from 11.3% in 2011 to 0% in 2017 (P < .001). We found no ward-level correlation between the proportion of carriers who completed clearance and new acquisitions (ρ = 0.02, P = .86).

CONCLUSIONS

A process for discontinuing CRE carrier status in PACHs led to a significant reduction in the percentage of patient-days in contact isolation without increasing CRE acquisitions among noncarriers.

Guía de práctica clínica para la tamización de pacientes con riesgo de colonización por Enterobacterales productores de carbapenemasas y el manejo de infecciones causadas por estas bacterias

Las infecciones por Enterobacterales productores de carbapenemasas (EPC) han aumentado en los últimos años. Colombia se ha convertido en un país endémico para este grupo de microorganismos y las infecciones que causan tienen un impacto importante en términos de morbilidad y mortalidad. La identificación temprana de los portadores de EPC que ingresan como pacientes a las instituciones de salud es necesaria para implementar medidas de aislamiento y control de infecciones adecuadas que limiten la diseminación de este tipo de microorganismos en los hospitales. Además, el tratamiento de estas infecciones es difícil debido a las limitadas alternativas terapéuticas disponibles y la escasez de estudios que demuestren su efectividad en este escenario. Por lo anterior, el objetivo del presente trabajo es desarrollar una guía de práctica clínica (GPC) para la tamización de pacientes con riesgo de colonización por EPC y para el manejo de pacientes con   infecciones, ya sea sospechadas o confirmadas, causadas por este tipo de bacterias, mediante un proceso de adaptación de GPC basado en la metodología ADAPTE. Con este propósito en mente, se hacen recomendaciones informadas en evidencia para realizar la tamización y oportuna identificación de portadores de EPC admitidos en instituciones hospitalarias, así como para el adecuado manejo farmacológico de las infecciones por EPC en este escenario.

A multi-institutional outbreak of New Delhi metallo-β-lactamase-producing Escherichia coli with subsequent acquisition of the Klebsiella pneumoniae carbapenemase gene

We characterized 57 isolates from a 2-phase clonal outbreak of New Delhi metallo-β-lactamase-producing Eschericha coli, involving 9 Israeli hospitals; all but 1 isolate belonged to sequence-type (ST) 410. Most isolates in the second phase harbored blaKPC-2 in addition to blaNDM-5. Genetic sequencing revealed most dual-carbapenemase-producing isolates to be monophyletically derived from a common ancestor.

Risk factors for the development of infections associated with carbapenemase-producing Enterobacteriaceae among previously colonized patients: A retrospective cohort study

Not all patients who acquire carbapenemase-producing Enterobacteriaceae (CPE) develop infections by these organisms; many remain only colonized. Of 54 CPE-colonized patients, 16 (30%) developed CPE infections. We identified indwelling urinary catheter exposure, exposure to intravenous colistin, and overseas transfer as variables associated with CPE infection development among colonized patients.

Tracing local and regional clusters of carbapenemase-producing Klebsiella pneumoniae ST512 with whole genome sequencing, Finland, 2013 to 2018

BackgroundTwo epidemiologically-unrelated clusters of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae were detected among several healthcare facilities (HCF) in Finland by routine surveillance using whole genome sequencing (WGS).AimThe objective was to investigate transmission chains to stop further spread of the responsible strain.MethodsIn this observational retrospective study, cases were defined as patients with K. pneumoniae KPC-3 sequence type (ST)512 strain detected in Finland from August 2013 to May 2018. Environmental specimens were obtained from surfaces, sinks and toilets in affected wards. WGS was performed on K. pneumoniae cultures using Illumina MiSeq platform and data were analysed using Ridom SeqShere software K. pneumoniae core genome multilocus sequence typing (cgMLST) scheme. Epidemiological information of the cases was provided by HCFs.ResultsWe identified 20 cases in six HCFs: cluster 1 included 18 cases in five HCFs and cluster 2 two cases in one HCF. In cluster 1, a link with a foreign country was unclear, 6/18 cases without overlapping stay had occupied the same room in one of the five HCFs within > 3 years. In cluster 2, the index case was transferred from abroad, both cases occupied the same room 8 months apart. A strain identical to that of the two cases in cgMLST was isolated from the toilet of the room, suggesting a clonal origin.ConclusionsThe clusters were mostly related to case transfer between facilities and likely involved environmental transmission. We show that CPE surveillance using WGS and collaboration between hospitals are crucial to identify clusters and trace transmission chains.

Perceptions of patients' and healthcare workers' experiences in cohort isolation units: a qualitative study

BACKGROUND

Given the scarce therapeutic options for carbapenemase-producing Enterobacterales (CPE), aggressive interventions are implemented to limit its spread among hospitalized patients. One such option is contact isolation by cohorting patients in designated units.

AIM

To describe the experiences in a cohort isolation unit (CIU) due to CPE from the perspectives of patients admitted to this unit and their families, and those of healthcare workers (HCWs) who served in the same unit.

METHODS

Qualitative study. Face-to-face, semi-structured interviews were conducted in a large tertiary hospital. Twenty-four participants were interviewed, including 15 HCWs, three patients and six family members. Data were coded using thematic analysis.

FINDINGS

The CIU provoked negative feelings such as fear, risk, loneliness, distrust and unfairness. They also created a sense of conflict with the curative assumptions of hospital care. The poor CIU infrastructure was echoed in perceptions of crowdedness in the site. Moreover, family members described HCWs' inconsistent protective behaviours that led them to a state of vigilance. The hospital infection control unit imparted and refreshed HCWs' knowledge and expected behaviours regarding the CIU. However, patients and families expressed dissatisfaction with the information, guidance and education regarding the 'why and how' of the CIU. They were not guided consistently about recommended behaviours after discharge. In retrospect, HCWs found that the CIU took a psychological, physical and professional toll.

CONCLUSION

The CIU was planned as a temporary containment mechanism. It needs to develop into a permanent system, capable of addressing the various needs of all involved.

Control of a hospital-wide outbreak of carbapenem-resistant Acinetobacter baumannii (CRAB) using the Israeli national carbapenem-resistant Enterobacteriaceae (CRE) guidelines as a model

OBJECTIVE

To study the effect of implementing the Israeli national carbapenem-resistant enterobacteriaceae (CRE) guidelines on controlling a hospital-wide outbreak of Acinetobacter baumannii (CRAB).

DESIGN

A before-and-after study from 2014 to 2018.

SETTING

A 740-bed, secondary-care hospital in central Israel.

INTERVENTION

Acquisition of CRAB was defined as a positive culture taken at least 48 hours after admission or a positive sample identified upon admission in a patient who had been readmitted within 30 days after discharge from our institution. The intervention included maintaining a case registry of all CRAB patients, cohorting patients under strict contact isolation, using dedicated nursing staff and equipment, rigorous cleaning, education and close monitoring of hospital staff, and involvement of hospital management.

RESULTS

In total, 210 patients were identified with hospital-acquired CRAB: 141 before the intervention and 69 after the intervention. CRAB acquisition rates decreased by 77%, from 1.3 per 1,000 admissions before the intervention (2014-2015) to 0.3 per 1,000 admissions after the intervention (2016-2018) (P < .001). The decrease in acquisitions was observed hospital-wide, year by year (P for trend, <.001). In 2018, only 7 new acquisitions were detected in internal medicine wards (P = .058) and none in the ICUs (P = .006).

CONCLUSIONS

A structured intervention based on the Israeli CRE management guidelines was successful in controlling a hospital-wide CRAB outbreak.

Institutional Burden of Carbapenemase-Producing Enterobacterales: The Effect of Changes in Surveillance Culture Methodology

An essential part of the Israeli intervention program aimed to contain the spread of carbapenemase-producing Enterobacterales (CPE) has been the establishment of national surveillance system, where the institutional rates are determined by both clinical and surveillance cultures. The objectives of the study were to analyze the effect of changes in surveillance culture media on the rates and microbiological characteristics of CPE in a multicenter study. The rates were compared during 2 years in and between four centers. Two centers (Tel-Aviv and Beilinson) had changed their surveillance media to CHROMagar™ mSuperCARBA™ after 1 year, and two centers (Rambam and Hillel-Yaffe) had continued to use CHROMagar KPC. There was an increase in the rates of surveillance CPE in Tel-Aviv and Beilinson following the change in media, whereas the rates remained the same or declined in Rambam and Hillel-Yaffe, respectively. The rates of clinical CPE remained unchanged in Rambam and Hillel-Yaffe, declined in Tel-Aviv, and increased in Beilinson but to a lesser extent compared with the increase in surveillance CPE. The relative composition of the CPE mechanisms and species changed in Tel-Aviv, with an increase in non-Klebsiella pneumoniae species and in carbapenemase other than KPC. Our study shows that changes in surveillance media may contribute to significant changes in the rate of surveillance CPE that may be irrespective of actual epidemiological changes. Therefore, determination of institutional burden of CPE and the assessment of intervention results should be based primarily on the rate of clinical CPE rather than surveillance culture reports.

Success of a National Intervention in Controlling Carbapenem-resistant Enterobacteriaceae in Israel's Long-term Care Facilities

BACKGROUND

Long-term care facilities (LTCFs) are a major reservoir of carbapenem-resistant Enterobacteriaceae (CRE) in healthcare facilities, contributing to rapid regional dissemination of CRE.

METHODS

In 2008, The Israeli National Center for Infection Control (NCIC) initiated a coordinated, comprehensive intervention in Israel's LTCFs, encompassing approximately 25000 beds in over 300 institutions. The intervention included implementation of population-tailored contact precautions and early detection of carriers. The NCIC established a real-time repository of all CRE carriers and events of acquisition, supervised information exchange between healthcare facilities and directed intervention at the institutional level during local outbreaks. CRE incidence was determined based on detection of CRE, either during LTFC stay or on admission to another facility. Prevalence was determined by a series of 5 cross-sectional surveys commenced between 2008 and 2015.

RESULTS

From January 2009 through December 2015, 5265 patients acquired CRE in LTCFs. During the study period, incidence of acquisition declined in all facility types, to approximately 50% of the baseline (P < .001). The number of skilled nursing facilities and nursing homes experiencing ≥ 5 CRE acquisitions annually decreased from 35 to 11 during this period. The point prevalence of newly detected CRE carriage in post-acute care hospitals decreased from 12.3% in the survey commenced in 2008 to 0.8% in that begun in 2015 (P < .001).

CONCLUSIONS

A national, coordinated intervention resulted in a sustained decrease in CRE incidence and prevalence in LTCFs. These results support the assumption that centrally coordinated intervention is an essential public health tool in reducing CRE in healthcare facilities.

Non-inferiority versus superiority trial design for new antibiotics in an era of high antimicrobial resistance: the case for post-marketing, adaptive randomised controlled trials

Antimicrobial resistance is one of the most important threats to global health security. A range of Gram-negative bacteria associated with high morbidity and mortality are now resistant to almost all available antibiotics. In this context of urgency to develop novel drugs, new antibiotics for multidrug-resistant Gram-negative bacteria (namely, ceftazidime-avibactam, plazomicin, and meropenem-vaborbactam) have been approved by regulatory authorities based on non-inferiority trials that provided no direct evidence of their efficacy against multidrug-resistant bacteria such as Enterobacteriaceae spp, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Burkholderia cepacia, and Acinetobacter baumannii. The use of non-inferiority and superiority trials, and selection of appropriate and optimal study designs, remains a major challenge in the development, registration, and post-marketing implementation of new antibiotics. Using an example of the development process of ceftazidime-avibactam, we propose a strategy for a new research framework based on adaptive randomised clinical trials. The operational research strategy has the aim of assessing the efficacy of new antibiotics in special groups of patients, such as those infected with multidrug-resistant bacteria, who were not included in earlier phase studies, and for whom it is important to establish an appropriate standard of care.

The Infinity War: How to Cope with Carbapenem-resistant Enterobacteriaceae

Carbapenem-resistant Enterobacteriaceae (CRE) are now spread worldwide. In Korea, the number of CRE isolation is rapidly increasing, and impending endemicity is a concern. To cope well with CRE, thorough infection control, such as active surveillance, early detection, strict contact precaution, cleaning the environment, and antibiotic stewardship is very important. Therapeutic options include polymyxin, tigecycline, fosfomycin or the combination of them with carbapenem, which is currently the mainstay of treatment. In addition, various combination regimens with new carbapenemase inhibitors such as avibactam, vaborbactam, or relebactam, and other classes of antimicrobials such as plazomicin and siderophore cephalosporin are in the process of evaluation.