Long-term control of carbapenemase-producing Enterobacteriaceae at the scale of a large French multihospital institution: a nine-year experience, France, 2004 to 2012

Evaluation of the Xpert Carba-R assay for quantifying carbapenemase-producing bacterial load in stool samples

BACKGROUND

The spread of Carbapenemase-producing Organisms (CPO) remains a major threat globally. Within clinical settings, the existing method of determining gene load involves traditional culture to determine bacterial load and polymerase-chain-reaction-based Xpert Carba-R Assay to determine carbapenemase gene type. However, there is a need for a fast and accurate method of quantifying CPO colonisation to study the risk of persistent CPO carriage.

OBJECTIVE

This study evaluated the accuracy of Xpert Carba-R Ct value in estimating carbapenamase producing bacterial loads in stool samples.

METHODS

Stool samples were obtained from an ongoing study investigating the household transmission of CPO in Singapore. Stool samples lacking carbapenemase producing organisms were spiked with organism carrying a single carbapenemase gene (blaKPC, blaNDM, blaVIM, blaOXA-48(-like) or blaIMP-1) and serially diluted before being subjected to Xpert Carba-R assay and traditional culture. Standard curves with regression lines showing correlation between Ct values and plate counts were generated. The standard curves were validated with stool samples collected from patients.

RESULTS

The limit of detection of blaNDM, blaKPC, and blaOXA-48 was approximately 103 cfu/mL, while that of blaIMP-1 and blaVIM was approximately 104 cfu/mL. Validation of the blaNDM and blaOXA-48 curves revealed average delta values of 0.56 log(cfu/mL) (95% CI 0.24-0.88) and 0.80 log(cfu/mL) (95% CI 0.53-1.07), respectively.

CONCLUSIONS

Our validation data for stool positive for blaNDM and blaOXA-48-type suggests that bacterial loads can be estimated within a reasonable range of error.

Cost-effectiveness of strategies to control the spread of carbapenemase-producing Enterobacterales in hospitals: a modelling study

Background

Spread of resistant bacteria causes severe morbidity and mortality. Stringent control measures can be expensive and disrupt hospital organization. In the present study, we assessed the effectiveness and cost-effectiveness of control strategies to prevent the spread of Carbapenemase-producing Enterobacterales (CPE) in a general hospital ward (GW).

Methods

A dynamic, stochastic model simulated the transmission of CPE by the hands of healthcare workers (HCWs) and the environment in a hypothetical 25-bed GW. Input parameters were based on published data; we assumed the prevalence at admission of 0.1%. 12 strategies were compared to the baseline (no control) and combined different prevention and control interventions: targeted or universal screening at admission (TS or US), contact precautions (CP), isolation in a single room, dedicated nursing staff (DNS) for carriers and weekly screening of contact patients (WSC). Time horizon was one year. Outcomes were the number of CPE acquisitions, costs, and incremental cost-effectiveness ratios (ICER). A hospital perspective was adopted to estimate costs, which included laboratory costs, single room, contact precautions, staff time, i.e. infection control nurse and/or dedicated nursing staff, and lost bed-days due to prolonged hospital stay of identified carriers. The model was calibrated on actual datasets. Sensitivity analyses were performed.

Results

The baseline scenario resulted in 0.93 CPE acquisitions/1000 admissions and costs 32,050 €/1000 admissions. All control strategies increased costs and improved the outcome. The efficiency frontier was represented by: (1) TS with DNS at a 17,407 €/avoided CPE case, (2) TS + DNS + WSC at a 30,700 €/avoided CPE case and (3) US + DNS + WSC at 181,472 €/avoided CPE case. Other strategies were dominated. Sensitivity analyses showed that TS + CP might be cost-effective if CPE carriers are identified upon admission or if the cases have a short hospital stay. However, CP were effective only when high level of compliance with hand hygiene was obtained.

Conclusions

Targeted screening at admission combined with DNS for identified CPE carriers with or without weekly screening were the most cost-effective options to limit the spread of CPE. These results support current recommendations from several high-income countries.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01149-0.

Rectal and Tracheal Carriage of Carbapenemase Genes and Class 1 and 2 Integrons in Patients in Neurosurgery Intensive Care Unit

The spread of multidrug-resistant Gram-negative bacteria, which is associated with the distribution of beta-lactamase genes and class 1 and 2 integrons, is a global problem. In this study, in the Moscow neurosurgery intensive care unit (neuro-ICU), the high prevalence of the above-stated genes was found to be associated with intestinal and tracheal carriage. Seven-point prevalence surveys, which included 60 patients in the neuro-ICU, were conducted weekly in the period from Oct. to Nov. 2019. A total of 293 clinical samples were analyzed, including 146 rectal and 147 tracheal swabs; 344 Gram-negative bacteria isolates were collected. Beta-lactamase genes (n = 837) were detected in the isolates, including beta-lactamase blaTEM (n = 162), blaSHV (n = 145), cephalosporinase blaCTX-M (n = 228), carbapenemase blaNDM (n = 44), blaKPC (n = 25), blaOXA-48 (n = 126), blaOXA-51-like (n = 54), blaOXA-40-like (n = 43), blaOXA-23-like (n = 8), and blaVIM (n = 2), as well as class 1 (n = 189) and class 2 (n = 12) integrons. One extensively drug-resistant Klebsiella pneumoniae strain (sequence type ST39 and capsular type K23), simultaneously carried beta-lactamase genes, blaSHV-40 and blaTEM-1B, three carbapenemase genes, blaNDM, blaKPC, and blaOXA-48, the cephalosporinase gene blaCTX-M, and two class 1 integrons. Before this study, such heavily armed strains have not been reported, suggesting the ongoing evolution of antibiotic resistance.

Clonal spread of carbapenemase-producing Enterobacteriaceae in a region, China

Background

The increasing number of carbapenemase-producing Enterobacterales (CPE) has become a serious problem globally. This study aimed to elucidate their geographically epidemiological characteristics.

Methods

Resistance genes were identified by polymerase chain reaction (PCR) and sequencing. Bacterial genotyping was studied using multilocus sequence typing (MLST) and wzi typing. The transferability of carbapenemase genes was determined by a broth mating method. The relationships between the rates of antimicrobial consumption and the prevalence of CRE were performed by Pearson's or Spearman's correlation analyses.

Results

A total of 930 phenotypically confirmed carbapenem-resistant Enterobacterales (CRE) isolates collected from 19 hospitals were genotypically characterized. K. pneumoniae (KP) and E. coli isolates were 785 (85.14%) and 96 (10.41%) among 922 CPE isolates. Two major carbapenemase genes blaKPC-2 and blaNDM in CPE isolates accounted for 84.6% (n = 780) and 13.77% (n = 127). ST11 comprised 86.83% (633/729) of KPC-2 KP isolates. Different combinations of extended spectrum-β-lactamase (ESBL) genes of blaSHV, blaCTX, and blaTEM were found in KPC-2 producing KP isolates, and blaCTM-M-14/15, blaSHV-11/12 and blaTEM-1 were common ESBL genotypes. The wzi typing method could further subdivide ST11 KP group into at least five subgroups, among which wzi209 (69.83%, 442/633) was the most frequently isolated, followed by wzi141 (25.28%, 160/633). Conjugation assays showed that high conjugation rates were observed in CPE (15.24%, 32/210) for NDM plasmids, but relatively low (8.1%, 17/210) for KPC-2 plasmids. Different STs, different wzis and temperature could influence plasmid conjugation efficiency. No associations between the rates of antibiotics consumption and CPE prevalence were observed. The number of intra-hospital and inter-hospital transfers of CPE patients increased gradually from 18 (17.82%, 101) and 12 (11.88%, 101) in 2015 to 63 (30.73%, 205) and 51 (24.88%, 205) in 2018 (p = 0.016 and p = 0.008), respectively. Evidence-based measures could effectively reduce the prevalence of ST11-wzi209 clone but failed to control the dissemination of ST11-wzi141 KP clone.

Conclusions

Clonal spread of CPE, especially KPC-2 ST11 KP was the key factor contributing to the CPE increase in the region. Continued vigilance for the importations should be maintained. Coordinated regional interventions are urgently needed to reduce CPE threat.

Prevention and control of highly antibiotic-resistant bacteria in a Pacific territory: Feedback from New Caledonia between 2004 and 2020

OBJECTIVE

Carbapenemase-producing Enterobacteriaceae (CRE) and Enterococcus faecium resistant to vancomycin (VRE) constitute major threats to public health worldwide. The Pacific area is concerned and has implemented strategies to control antimicrobial resistance (AMR). However, accurate epidemiological data are rarely reported. Our study aimed to present the strategies applied to prevent and control the spread of highly resistant bacteria in the Pacific territory of New Caledonia.

PATIENTS AND METHODS

Cohort prospective study of all cases of highly resistant bacteria (HRB) isolated in New Caledonia from September 2004 to December 2020. Evaluation of the impact of the infection control measures implemented in healthcare settings: screening strategy, cohorting unit, IT tools and control of antibiotic prescriptions.

RESULTS

A total of 346 patients with HRB were identified. Most of them (63.0%) were infected or colonized by VRE (n=218) and 128 by CRE. While the number of CREs significantly increased from 2013 to 2020 (P<0.0001), control procedures have limited their dissemination. Most patients were colonized by IMP-4-CRE (n=124/128). The incidence density of VRE significantly decreased from 38.52 for 100,000 hospitalisation-days in 2015 to 4.19 for 100,000 hospitalisation-days in 2019 due to systematic screening of patients before sanitary repatriation from Australia and cohorting implementation. The risk of VRE diffusion is now well under control.

CONCLUSIONS

Our study confirms that it is possible to control the spread of AMR in a circumscribed territory by means of a global control strategy involving screening, cohorting unit, IT tools and antibiotic prescription controls.

Comparison of the Clinical Outcomes of Patients With Positive Xpert Carba-R Tests for Carbapenemase-Producing Enterobacterales According to Culture Positivity

Background

We aimed to compare the clinical outcomes of patients with positive Xpert Carba-R assay results for carbapenemase-producing Enterobacterales (CPE) according to CPE culture positivity.

Methods

We retrospectively collected data for patients with positive CPE (positive Xpert Carba-R or culture) who underwent both tests from August 2018 to March 2021 in a 2700-bed tertiary referral hospital in Seoul, South Korea. We compared the clinical outcomes of patients positive for Xpert Carba-R according to whether they were positive (XPCP) or negative (XPCN) for CPE culture.

Results

Of 322 patients with CPE who underwent both Xpert Carba-R and culture, 313 (97%) were positive for Xpert Carba-R for CPE. Of these, 87 (28%) were XPCN, and 226 (72%) were XPCP. XPCN patients were less likely to have a history of previous antibiotic use (75.9% vs 90.3%; P = .001) and to have Klebsiella pneumoniae carbapenemase (21.8% vs 48.9%; P < .001). None of the XPCN patients developed infection from colonization within 6 months, whereas 13.4% (29/216) of the XPCP patients did (P < .001). XPCN patients had lower transmission rates than XPCP patients (3.0% [9/305] vs 6.3% [37/592]; P = .03). There was no significant difference in CPE clearance from positive culture results between XPCN and XPCP patients (40.0% [8/20] vs 26.7% [55/206]; P = .21).

Conclusions

Our study suggests that XPCN patients had lower rates of both infection and transmission than XPCP patients. The Xpert Carba-R assay is clinically useful not only for rapid identification of CPE but also for predicting risks of infection and transmission when performed along with culture.

Neonates with Maternal Colonization of Carbapenemase-Producing, Carbapenem-Resistant Enterobacteriaceae: A Mini-Review and a Suggested Guide for Preventing Neonatal Infection

Carbapenemase-producing, carbapenem-resistant Enterobacteriaceae (CP-CRE) are highly drug-resistant Gram-negative bacteria. They include New Delhi metallo-ß-lactamase (NDM)-producing carbapenemase (50.4% of all species in Ontario). Antibiotic challenges for resistant bacteria in neonates pose challenges of unknown dosing and side effects. We report two antenatally diagnosed CP-CRE colonization scenarios with the NDM 1 gene. The case involves extreme preterm twins who had worsening respiratory distress at birth requiring ventilator support, with the first twin also having cardiovascular instability. They were screened for CP-CRE, and a polymyxin antibiotic commenced. In the delivery room, neonatal intensive care unit (NICU) and the follow-up clinic, in collaboration with the interdisciplinary group, contact precautions and isolation procedures were instituted. None of the infants exhibited infection with CP-CRE. Consolidating knowledge with regard to CP-CRE and modifying human behavior associated with its spread can mitigate potential negative consequences. This relates to now and later, when travel and prolific human to human contact resumes, from endemic countries, after the current COVID-19 pandemic. Standardized efforts to curb the acquisition of this infection would be judicious given the challenges of treatment and continued emerging antibiotic resistance. Simple infection control measures involving contact precautions, staff education and parental cohorting can be useful and cost-effective in preventing transmission. Attention to NICU specific measures, including screening of at-risk mothers (invitro fertilization conception) and their probands, careful handling of breastmilk, judicious antibiotic choice and duration of treatment, is warranted. What does this study add? CP-CRE is a nosocomial infection with increasing incidence globally, and a serious threat to public health, making it likely that these cases will present with greater frequency to the NICU team. Only a few similar cases have been reported in the neonatal literature. Current published guidelines provide a framework for general hospital management. Still, they are not specific to the NICU experience and the need to manage the parents' exposure and the infants. This article provides a holistic framework for managing confirmed or suspected cases of CP-CRE from the antenatal care through the NICU and into the follow-up clinic targeted at preventing or containing the spread of CP-CRE.

Epidemiology and risk factors of rectal colonization of carbapenemase-producing Enterobacteriaceae among high-risk patients from ICU and HSCT wards in a university hospital

Background

Nosocomial carbapenemase-producing Enterobacterieceae (CPE) infections constitute a major global health concern and are associated with increased morbidity and mortality. Rectal colonization with CPE is a risk factor for bacterial translocation leading to subsequent endogenous CPE infections. This prospective observational study was aimed to investigate the prevalence and epidemiology of rectal colonization of CPE, the carbapenemase genotypes, and to identify the independent risk factors for the acquisition of CPE colonization in high-risk patients from ICU and HSCT wards in a university hospital in China.

Methods

In a prospective cohort study, 150 fecal samples from rectal swabs were consecutively obtained for inpatients from the intensive care unit (ICU) and hematopoietic stem cell transplantation (HSCT) wards from November 2018 to May 2019, and screening test for CPE was conducted by using prepared in-house trypsin soybean broth (TSB) selective media and MacConkey agar. Antimicrobial susceptibility was determined by the broth microdilution method and carbapenemase genes were characterized by both the GeneXpert Carba-R and PCR for bla_KPC, bla_NDM, bla_IMP, bla_VIM and bla_OXA. Multi-locus sequence typing (MLST) was employed to characterize the genetic relationships among the carbapenemase-producing K. Pneumonia (CPKP) isolates. In order to further investigate the risk factors and clinical outcomes of CPE colonization, a prospective case-control study was also performed.

Results

Twenty-six suspected CPE strains, including 17 Klebsiella pneumoniae, 6 Escherichia coli, 1 Citrobacter freundii, 1 Enterobacter Kobe, and 1 Raoultella ornithinolytica, were identified in 25 non-duplicated rectal swab samples from 25 patients, with a carriage rate of 16.67% (25/150). Through GeneXpert Carba-R and subsequent PCR and sequencing, all the suspected CPE isolates were identified to be positive for the carbapenemase genes, of which 17 were bla_KPC-carriers, and another 9 were bla_NDM-producers. MLST designated all the CPKP isolates to be ST11 clone. Multivariate analysis indicated that urinary system diseases, operation of bronchoscopy, and combined use of antibiotics were independent risk factors for acquiring CPE colonization in high-risk patients from the ICU and HSCT wards.

Conclusions

This study revealed a high prevalence of rectal CPE colonization in high-risk patients from ICU and HSCT wards, and a predominant colonization of the KPC-producing K. pneumoniae clone ST11. Stricter infection control measures are urgently needed to limit the dissemination of CPE strains, especially in patients who were afflicted by urinary system diseases, have underwent bronchoscopy, and were previously exposed to combined antibiotic use.

Assessing the role of inter-facility patient transfer in the spread of carbapenemase-producing Enterobacteriaceae: the case of France between 2012 and 2015

The spread of carbapenemase-producing Enterobacteriaceae (CPE) in healthcare settings is a major public health threat that has been associated with cross-border and local patient transfers between healthcare facilities. Since the impact of transfers on spread may vary, our study aimed to assess the contribution of a patient transfer network on CPE incidence and spread at a countrywide level, with a case study of France from 2012 to 2015. Our results suggest a transition in 2013 from a CPE epidemic sustained by internationally imported episodes to an epidemic sustained by local transmission events through patient transfers. Incident episodes tend to occur within close spatial distance of their potential infector. We also observe an increasing frequency of multiple spreading events, originating from a limited number of regional hubs. Consequently, coordinated prevention and infection control strategies should focus on transfers of carriers of CPE to reduce regional and inter-regional transmission.

Epidemiological and Microbiome Associations Between Klebsiella pneumoniae and Vancomycin-Resistant Enterococcus Colonization in Intensive Care Unit Patients

Background

Prior colonization by Klebsiella pneumoniae and vancomycin-resistant Enterococci (VRE) is associated with subsequent infection, particularly in intensive care unit (ICU) populations. Screening for VRE colonization, but not K. pneumoniae, is routinely performed in some health care systems. Identification of patient factors associated with K. pneumoniae colonization could enable infection prevention.

Methods

ICU patients were screened for VRE and K. pneumoniae by rectal swab culture over 2 time periods: July–October 2014 (n = 1209) and January–May 2016 (n = 1243). Patient demographics, baseline laboratory data, comorbidities, and outcomes were analyzed. 16S rRNA gene-based analysis was performed on a subset of patients (n = 248) to identify microbiota characteristics associated with VRE and K. pneumoniae colonization.

Results

K. pneumoniae colonization (17.3% of patients in the 2014 cohort, 7.3% in 2016) was significantly associated with VRE colonization in multivariable analysis (P = .03 in 2016; P = .08 in 2014). VRE colonization was associated with poor underlying health, whereas K. pneumoniae colonization was associated with advanced age. The most prevalent operational taxonomic units were Escherichia coli/Shigella spp., Klebsiella, and Enterococcus, consistent with high rates of detectable K. pneumoniae and VRE by culture. Microbial community structure in noncolonized patients was significantly different from those with VRE, K. pneumoniae, or both, attributable to differences in the relative abundance of Klebsiella and Enterococcus.

Conclusions

K. pneumoniae co-colonizes with VRE and is a predominant taxon in ICU patients, but colonization was not associated with significant comorbidities. Screening for K. pneumoniae and VRE simultaneously could be an efficient approach for novel infection prevention strategies.

Efficiency of different control measures for preventing carbapenemase-producing enterobacteria and glycopeptide-resistant Enterococcus faecium outbreaks: a 6-year prospective study in a French multihospital institution, January 2010 to December 2015

An infection control programme was implemented in a 21,000-bed multihospital institution for controlling the spread of carbapenemase-producing Enterobacteriaceae (CPE) and glycopeptide-resistant Enterococcus faecium (GRE), classified as ‘emergent extensively drug-resistant bacteria’ (eXDR) in France. We evaluated factors associated with outbreaks occurrence (n = 103), which followed 901 eXDR introductions (index case followed or not by secondary cases) from 2010 to 2015. In univariate analysis, knowing that patients had been hospitalised abroad, bacterial species (GRE vs CPE, as well as the CPE Klebsiella pneumoniae compared with the other Enterobacteriaceae species) and type of measures implemented within the first 2 days of hospitalisation were associated with outbreaks occurrence, but not the type of wards where carriers were hospitalised, nor the eXDR colonisation or infection status. In multivariate analysis, occurrence of outbreaks was significantly lower when contact precautions (odds ratio (OR): 0.34; 95% confidence interval (CI): 0.22–0.54) and even more when dedicated nursing staff (OR: 0.09; 95% CI: 0.02–0.39) were implemented around eXDR index cases within the first 2 days of hospitalisation (p < 10 ^− 3). GRE introductions were more frequently associated with occurrence of outbreaks than CPE (OR: 3.58; 95% CI: 2.32–5.51, p < 10 ^− 3). A sustained and coordinated strategy is efficient to limit the spread of eXDR at the scale of a large health institution.

Epidemiology of carbapenemase-producing Enterobacteriaceae in a pediatric hospital in a country with high endemicity

BACKGROUND

Little is known about epidemiology of carbapenemase-producing Enterobacteriaceae (CPE) in children. Aim of this study was to describe CPE epidemiology in a tertiary care pediatric hospital in Italy that admits patients coming from geographic areas with high diffusion of CPE.

METHODS

Prospective evaluation of the proportion and rates per 100,000 hospital discharges (D) or hospitalization-days (HD) of invasive infections due to CPE from 2013 to 2017 and of CPE infections and colonizations from 2014 to 2017. Disease-preventing strategies comprised patients' screening at admission, pre-emptive contact isolation precautions pending cultures results, and bundles for prevention of healthcare associated infections.

RESULTS

From 2013 to 2017 CPE represented 3.5% of all invasive infections due to Enterobacteriaceae, with rates ranging 7.30-14.33 for D and 1.03-2.06 for HD, without major changes over time. On the contrary, overall rates of isolates increased from 83.03 to 191.34 for D and from 12.21 to 28.35 for HD. The intra-hospital diffusion consisted of 2 small outbreaks without invasive diseases in 2014-2015, and sporadic, not epidemiologically-related cases in 2016-2017. Globally, Escherichia coli and Klebsiella pneumoniae represented 64% of identified CPE, while 70% of carbapenemases identified were metallo-beta-lactamases (VIM or NDM), with changes over time.

CONCLUSIONS

In our center metallo-beta lactamases were the most frequently identified carbapenemases in Enterobacteriaceae and E. coli and K. pneumoniae the most frequently isolated pathogens carrying these enzymes. A proactive management strategy was effective in containing in-hospital spreading.

Is cohorting the only solution to control carbapenemase-producing Enterobacteriaceae outbreaks? A single-centre experience

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) are a major health issue. Cohorting may help to control spread of CPEs in hospitals, but is expensive and hard to implement.

AIM

To identify ward variables associated with CPE in-hospital transmission in a hospital where cohorting has never been implemented.

METHODS

Cohort prospective study, comparing 14-consecutive-day periods regarding in-hospital transmission. Each period met the two following conditions: (i) CPE carriers/infected admitted for ≥48 h; (ii) 80% of relative contact patients were screened at least twice. Periods (a) with no acquired CPE case among relative contact patients were compared to periods (b) during which one or more CPE case acquisition was identified. Variables potentially associated with CPE transmission were assessed: colonization pressure, caregiver:patient ratio, hand hygiene compliance, hydro-alcoholic product consumption, antibiotic consumption, and infection control team (ICT) involvement on the ward.

FINDINGS

Sixty-eight periods of two consecutive weeks were included, 18 (26.5%) included at least one CPE case acquisition. By multivariate analysis, colonization pressure (odds ratio: 1.12; 95% confidence interval: 1.0-1.25; P = 0.042) and antibiotic consumption (2.41; 1.02-5.66; P = 0.044) were associated with CPE in-hospital transmission. Caregiver:patient ratio potentiated both these variables, suggesting a role for understaffing in CPE transmission.

CONCLUSION

Understanding ward variables associated with CPE spread can help design suitable solutions. Colonization pressure and antibiotic consumption seems to be driving in-hospital transmission, along with caregiver:patient ratio. In presence of high colonization pressure, dedicated healthcare workers for managing CPE patients should be implemented. Co-ordination between ICT and antimicrobial stewardship team is also crucial to prevent CPE spread.

A Systematic Review and Meta-analyses of the Clinical Epidemiology of Carbapenem-Resistant Enterobacteriaceae

Carbapenem-resistant Enterobacteriaceae (CRE) are major health care-associated pathogens and responsible for hospital outbreaks worldwide. To prevent a further increase in CRE infections and to improve infection prevention strategies, it is important to summarize the current knowledge about CRE infection prevention in hospital settings. This systematic review aimed to identify risk factors for CRE acquisition among hospitalized patients. In addition, we summarized the environmental sources/reservoirs and the most successful infection prevention strategies related to CRE. A total of 3,983 potentially relevant articles were identified and screened. Finally, we included 162 studies in the systematic review, of which 69 studies regarding risk factors for CRE acquisition were included in the random-effects meta-analysis studies. The meta-analyses regarding risk factors for CRE acquisition showed that the use of medical devices generated the highest pooled estimate (odds ratio [OR] = 5.09; 95% confidence interval [CI] = 3.38 to 7.67), followed by carbapenem use (OR = 4.71; 95% CI = 3.54 to 6.26). To control hospital outbreaks, bundled interventions, including the use of barrier/contact precautions for patients colonized or infected with CRE, are needed. In addition, it is necessary to optimize the therapeutic approach, which is an important message to infectious disease specialists, who need to be actively involved in a timely manner in the treatment of patients with known CRE infections or suspected carriers of CRE.

Trends in carbapenemase-producing Enterobacteriaceae, France, 2012 to 2014

In 2014, a total of 2,976 Enterobacteriaceae isolates with decreased susceptibility to carbapenems were received at the French Associated National Reference Center for Antibiotic Resistance (NRC) and were characterised for their molecular resistance mechanism to carbapenems and compared with results obtained during 2012 and 2013.The overall number of enterobacterial isolates with decreased susceptibility to carbapenems received at the NRC rapidly increased (more than twofold in two years) with a growing proportion of carbapenemase producers (23.1% in 2012 vs 28.6% in 2013 vs 36.2% in 2014). Between 2012 and 2014, the main carbapenemase type was OXA-48, with an increase in OXA-48 variants (mostly OXA-181) and NDM producers, whereas the number KPC producers decreased. We identified a potential spread of OXA-181 producers in the tropical region of Africa. Finally, OXA-48 and OXA-48-related enzymes remained the predominant carbapenemases in France. The number of carbapenemase-producing Escherischia coli isolates was multiplied by fivefold between 2012 and 2014, suggesting a possible dissemination in the community.

Carbapenem-Resistant Enterobacteriaceae: A Strategic Roadmap for Infection Control

The incidence of carbapenem-resistant Enterobacteriaceae (CRE) has increased worldwide with great regional variability. Infections caused by these organisms are associated with crude mortality rates of up to 70%. The spread of CRE in healthcare settings is both an important medical problem and a major global public health threat. All countries are at risk of falling victim to the emergence of CRE; therefore, a preparedness plan is required to avoid the catastrophic natural course of this epidemic. Proactive and adequate preventive measures locally, regionally, and nationally are required to contain the spread of these bacteria. The keys to success in preventing the establishment of CRE endemicity in a region are early detection through targeted laboratory protocols and containment of spread through comprehensive infection control measures. This guideline provides a strategic roadmap for infection control measures based on the best available evidence and expert opinion, to enable preparation of a multifaceted preparedness plan to abort epidemics of CRE. Infect Control Hosp Epidemiol 2017;38:580-594.

Development of an algorithm for phenotypic screening of carbapenemase-producing Enterobacteriaceae in the routine laboratory

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) are difficult to identify among carbapenem non-susceptible Enterobacteriaceae (NSE). We designed phenotypic strategies giving priority to high sensitivity for screening putative CPE before further testing.

METHODS

Presence of carbapenemase-encoding genes in ertapenem NSE (MIC > 0.5 mg/l) consecutively isolated in 80 French laboratories between November 2011 and April 2012 was determined by the Check-MDR-CT103 array method. Using the Mueller-Hinton (MH) disk diffusion method, clinical diameter breakpoints of carbapenems other than ertapenem, piperazicillin+tazobactam, ticarcillin+clavulanate and cefepime as well as diameter cut-offs for these antibiotics and temocillin were evaluated alone or combined to determine their performances (sensitivity, specificity, positive and negative likelihood ratios) for identifying putative CPE among these ertapenem-NSE isolates. To increase the screening specificity, these antibiotics were also tested on cloxacillin-containing MH when carbapenem NSE isolates belonged to species producing chromosomal cephalosporinase (AmpC) but Escherichia coli.

RESULTS

Out of the 349 ertapenem NSE, 52 (14.9%) were CPE, including 39 producing OXA-48 group carbapenemase, eight KPC and five MBL. A screening strategy based on the following diameter cut offs, ticarcillin+clavulanate <15 mm, temocillin <15 mm, meropenem or imipenem <22 mm, and cefepime <26 mm, showed 100% sensitivity and 68.1% specificity with the better likelihood ratios combination. The specificity increased when a diameter cut-off <32 mm for imipenem (76.1%) or meropenem (78.8%) further tested on cloxacillin-containing MH was added to the previous strategy for AmpC-producing isolates.

CONCLUSION

The proposed strategies that allowed for increasing the likelihood of CPE among ertapenem-NSE isolates should be considered as a surrogate for carbapenemase production before further CPE confirmatory testing.

Multidrug-resistant bacteria in hematology patients: emerging threats

Multidrug-resistant (MDR) bacteria, particularly Gram negatives, such as Enterobacteriaceae resistant to third-generation cephalosporins or carbapenems and MDR Pseudomonas aeruginosa, are increasingly frequent in hematology patients. The prevalence of different resistant species varies significantly between centers. Thus, the knowledge of local epidemiology is mandatory for deciding the most appr-opriate management protocols. In the era of increasing antibiotic resistance, empirical therapy of febrile neutropenia should be individualized. A de-escalation approach is recommended in case of severe clinical presentation in patients who are at high risk for infection with a resistant strain. Targeted therapy of an MDR Gram negative usually calls for a combination treatment, although no large randomized trials exist in this setting. Infection control measures are the cornerstone of limiting the spread of MDR pathogens in hematology units.

Antimicrobial resistance: one world, one fight!

The lack of new antibiotic classes calls for a cautious use of existing agents. Yet, every 10 min, almost two tons of antibiotics are used around the world, all too often without any prescription or control. The use, overuse and misuse of antibiotics select for resistance in numerous species of bacteria which then renders antimicrobial treatment ineffective. Almost all countries face increased antimicrobial resistance (AMR), not only in humans but also in livestock and along the food chain. The spread of AMR is fueled by growing human and animal populations, uncontrolled contamination of fresh water supplies, and increases in international travel, migration and trade. In this context of global concern, 68 international experts attending the fifth edition of the World HAI Resistance Forum in June 2015 shared their successes and failures in the global fight against AMR. They underlined the need for a “One Health” approach requiring research, surveillance, and interventions across human, veterinary, agricultural and environmental sectors. This strategy involves concerted actions on several fronts. Improved education and increased public awareness are a well-understood priority. Surveillance systems monitoring infections need to be expanded to include antimicrobial use, as well as the emergence and spread of AMR within clinical and environmental samples. Adherence to practices to prevent and control the spread of infections is mandatory to reduce the requirement of antimicrobials in general care and agriculture. Antibiotics need to be banned as growth promoters for farm animals in countries where it has not yet been done. Antimicrobial stewardship programmes in animal husbandry have proved to be efficient for minimising AMR, without compromising productivity. Regarding the use of antibiotics in humans, new tools to provide highly specific diagnoses of pathogens can decrease diagnostic uncertainty and improve clinical management. Finally, infection prevention and control measures – some of them as simple as hand hygiene – are essential and should be extended beyond healthcare settings. Aside from regulatory actions, all people can assist in AMR reduction by limiting antibiotic use for minor illnesses. Together, we can all work to reduce the burden of AMR.

Prolonged delay for controlling KPC-2-producing Klebsiella pneumoniae outbreak: the role of clinical management

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) are becoming of immediate concern for infection control policies. Prompt detection of CPE on health care setting admission is crucial to halt the spread of an outbreak. We report a cluster of 13 Klebsiella pneumoniae carbapenemase (KPC)-2-producing K pneumoniae cases in a tertiary care hospital.The objective of this study was to identify contributing factors originating the outbreak.

METHODS

An outbreak investigation was conducted using descriptive epidemiology, observation of health care practices, and interviews of management staff. A root cause analysis was performed to identify patent and latent failures of infection control measures using the association of litigation and risk management method.

RESULTS

The main patent failure was the delay in identifying KPC-2-producing K pneumoniae carriers. Contributing factors were work and environmental factors: understaffing, lack of predefined protocols, staff members' characteristics, and underlying patients' characteristics. Latent failures were as follows: no promotion of the national guidelines for prevention of CPE transmission, no clear procedure for the management of patients hospitalized abroad, no clear initiative for promoting a culture of quality in the hospital, biologic activity recently outsourced to a private laboratory, and poor communication among hospital members.

CONCLUSION

Clinical management should be better promoted to control hospital outbreaks and should include team work and safety culture.

Carbapenemase-producing Enterobacteriaceae: use of a dynamic registry of cases and contacts for outbreak management

BACKGROUND

The emergence and spread of carbapenemase-producing Enterobacteriaceae (CPE) have become a major public health problem. Control and prevention of CPE infections hinge on isolation precautions for carriers and active screening and follow-up of contacts.

AIM

To implement an open registry of cases and contacts for acute outbreak management, long-term data collection and epidemiological investigation.

METHODS

All cases, defined as patients (infected or colonized) with a CPE-positive culture during their hospitalization, and contacts (e.g. patients cared for by the same healthcare team as a case) were registered in an ongoing database. Hospital stays were cross-referenced for every new entry and epidemiological links (e.g. shared contacts) investigated. All cases and contacts not cleared by complete screening were registered on an active list.

FINDINGS

Between October 2012 and November 2014, we registered 30 cases and 1268 contacts, among which 24 were linked to two or three separate cases. Only 6.5% of contacts fulfilled complete screening with three rectal swabs, and 1145 contacts are still registered on the active surveillance list. Two outbreaks (12 and nine cases) occurred nine months apart. Cross-referencing of hospital stays using the registry revealed epidemiological links between seemingly unrelated cases of CPE-positive patients and suggested an environmental source of transmission, which was demonstrated thereafter.

CONCLUSION

We implemented a simple and multi-purpose tool to manage CPE episodes and investigate epidemiological links. Efforts are necessary to improve screening of contact patients who may be occult sources of transmission. A regional registry could be helpful.

Evaluation of Two Phenotypic Screening Tests for Carbapenemase-Producing Enterobacteriaceae

We evaluated the performance of two rapid tests for detection of carbapenemase-producing Enterobacteriaceae (CPE) strains. The sensitivities and the specificities were 97.6% and 94.4% for the Rapid CARB Screen and 98.8% and 93.1% for the KPC/MBL & OXA-48 Confirm tests, providing the usefulness of these tools for screening CPE in microbiology wards.

Reconsidering Contact Precautions for Endemic Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus

BACKGROUND

Whether contact precautions (CP) are required to control the endemic transmission of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) in acute care hospitals is controversial in light of improvements in hand hygiene, MRSA decolonization, environmental cleaning and disinfection, fomite elimination, and chlorhexidine bathing.

OBJECTIVE

To provide a framework for decision making around use of CP for endemic MRSA and VRE based on a summary of evidence related to use of CP, including impact on patients and patient care processes, and current practices in use of CP for MRSA and VRE in US hospitals.

DESIGN

A literature review, a survey of Society for Healthcare Epidemiology of America Research Network members on use of CP, and a detailed examination of the experience of a convenience sample of hospitals not using CP for MRSA or VRE.

PARTICIPANTS

Hospital epidemiologists and infection prevention experts.

RESULTS

No high quality data support or reject use of CP for endemic MRSA or VRE. Our survey found more than 90% of responding hospitals currently use CP for MRSA and VRE, but approximately 60% are interested in using CP in a different manner. More than 30 US hospitals do not use CP for control of endemic MRSA or VRE.

CONCLUSIONS

Higher quality research on the benefits and harms of CP in the control of endemic MRSA and VRE is needed. Until more definitive data are available, the use of CP for endemic MRSA or VRE in acute care hospitals should be guided by local needs and resources.

Infect Control Hosp Epidemiol 2015;36(10):1163–1172

Carbapenemase-producing Enterobacteriaceae in Sweden 2007-2013: Experiences from seven years of systematic surveillance and mandatory reporting

Carbapenemase-producing Enterobacteriaceae (CPE) are increasing worldwide, and are a major threat to healthcare systems. Recent European data support that many countries have interregional spread of CPE or an endemic situation. In Sweden mandatory laboratory reporting of CPE of both colonisation and infection has been practiced since 2007 and since 2012 also by treating physicians. Between 2007 and 2013, 94 cases of CPE were detected in Sweden, out of which 24 were considered to cause clinical infections (bloodstream infection (n=4), urinary tract infection (n=12), wound infection (n=4), respiratory tract infection (n=2) and catheter related (n=2). The majority were detected in the hospital setting through faecal screening or as probable colonisers in clinical cultures. Travel abroad was observed in the majority of the patients (81%), and among them 84% had been hospitalised. During the study period only two chains of transmissions in Swedish hospitals were reported, involving four patients. Klebsiella pneumoniae was the primarily isolated species (n=57) followed by Escherichia coli (n=29). blaNDM was the predominant carbapenemase gene (n=36), followed by blaOXA-48-group, blaKPC and blaVIM. In 26/94 cases (28%) isolates were categorised as possible XDR (extensively drug-resistant). CPE are increasing in Sweden, but are still at a comparably low level.

Control of emerging extensively drug-resistant organisms (eXDRO) in France: a survey among infection preventionists from 286 healthcare facilities

We performed a multicenter survey in May-June 2012 to assess strategies in preventing the spread of emerging extensively drug-resistant organisms (eXDRO), including glycopeptide-resistant enterococci and carbapenemase-producing Enterobacteriaceae, in a convenient sample of French healthcare facilities (HCFs). The collected data included organization and measures to: (1) identify patients at risk for carrying eXDRO, (2) investigate and control sporadic cases or outbreaks, and (3) describe prior 2010-2012 episodes with one or more colonized patients. Of the 286 participating HCFs, 163 (57 %) and 134 (47 %) reported having a specific procedure to detect repatriates or patients hospitalized in foreign countries within the last year, respectively. Among the 97 HCFs with prior at-risk patient management experience, contact precautions, hospitalization in a single room, and screening for eXDRO carriage were quasi-systematically performed (n = 92/97, 95 %). The alleged time between admission and alert ranged from 24 to 48 h after the patient's admission; 203 (71 %) HCFs recommended obtaining three successive negative screening samples to declare a patient free of eXDRO colonization. During the last two years, 64 HCFs (23 %) had to manage at least one eXDRO case, with a total of 20 outbreaks with more than one secondary case. This first national survey shows that French HCFs were not totally ready to control eXDRO spread in 2012. Their previous experiences and capacities in controlling eXDRO outbreaks are quite heterogeneous from one hospital to another. Further researches are needed in order to understand the constraints in applying national guidance.

French recommendations for the prevention of 'emerging extensively drug-resistant bacteria' (eXDR) cross-transmission

Controlling the spread of multi- or extensively drug-resistant bacteria (MDR or XDR) includes a dual strategy for reducing antibiotic prescriptions and preventing their spread from patient carriers. Standard precautions are applicable to all health professionals caring for any patients; additional barrier precautions (isolation) are recommended for patients carrying transmissible infectious diseases or MDR bacteria in sporadic or epidemic situations. Moreover, additional precautions may be required for populations at particular risk of infection or colonization by emerging XDR (eXDR), defined in our country as carbapenemase-producing Enterobacteriaceae and vancomycin-resistant enterococci. Our ability to detect and identify eXDR carriers early and ensure their follow-up, through effective communication between all those involved, is a significant challenge for controlling their spread. Thus, the French High Committee for Public Health has updated and standardized all French existing recommendations concerning the prevention of the cross-transmission of these bacteria, and these recommendations are summarized in this review. The recommendations are based on scientific and operational knowledge up to 2013. Different preventive strategies are recommended for patients found to be carrying eXDR and those who are considered to be at risk of having eXDR because of a history of contact. The local context, the experience of the infection control team, the different times at which detection of eXDR takes place (during admission, hospitalization, etc.) and the epidemiological situation (sporadic cases, clusters, outbreaks, widespread epidemic) must be included in risk assessments that in turn inform the control measures that should be applied in each clinical circumstance.

Challenges of controlling a large outbreak of OXA-48 carbapenemase-producing Klebsiella pneumoniae in a French university hospital

A large outbreak of OXA-48 carbapenemase-producing Klebsiella pneumoniae at Nantes University Hospital was investigated. The index case had no history of travel or hospitalization abroad and had been hospitalized in the internal medicine department for more than one month when the epidemic strain was isolated from a urine sample in June 2013. Seventy-two secondary cases were detected by weekly screening for gastrointestinal colonization during the two phases of the outbreak from June to October 2013 (33 cases) and from November 2013 to August 2014 (39 cases). Spread of the epidemic strain was attributed to the proximity of, and staff movement between, the infectious diseases (32 cases) and the internal medicine (26 cases) departments; 14 secondary cases were also observed in the renal transplant department following the transfer of an exposed patient from the infectious diseases department. Most of the patients (90%) were colonized and no death was linked to the epidemic strain. More than 3000 contact patients were reviewed and 6000 rectal swabs were performed. Initial control measures failed to control the outbreak owing to the late detection of the index case. The late implementation of three successive cohort units, the large number of transfers between wards, and the frequent readmission of cases contributed to the incomplete success of control measures.

Management of multidrug resistant bacterial endemic

The fight against multi-drug resistant Gram-negative bacilli (MDRGNB), especially extended-spectrum β-lactamase producing Enterobacteriaceae, is about to be lost in our country. The emergence of new resistance mechanisms to carbapenems in these Enterobacteriaceae exposes patients to a risk of treatment failure without any other therapeutic options. This dramatic situation is paradoxical because we are well aware of the 2 major factors responsible for this situation: 1) MDRO cross-transmission, associated with a low compliance to standard precautions, especially hand hygiene, and 2) overexposure of patients to antibiotics. The implementation of a "search and isolate" policy, which was justified to control the spread of some MDRO that remained rare in the country, was not associated with a better adherence to standard precautions. The antibiotic policy and the measures implemented to control antibiotic consumptions have rarely been enforced and have shown inconsistent results. Notably, no significant decrease of antibiotic consumption has been observed. There is no excuse for these poor results, because some authors evaluating the effectiveness of programs for the control of MDRO have reported their positive effects on antimicrobial resistance without any detrimental effects. It is now urgent to deal with the 2 major factors by establishing an educational and persuasive program with quantified and opposable objectives. Firstly, we have to improve the observance of hand hygiene above 70%. Secondly, we have to define and reach a target for the reduction of antibiotic consumption both in community and in hospital settings.