Potential role of active surveillance in the control of a hospital-wide outbreak of carbapenem-resistant Klebsiella pneumoniae infection

Healthcare Antibiotic Resistance Prevalence - DC (HARP-DC): A Regional Prevalence Assessment of Carbapenem-Resistant Enterobacteriaceae (CRE) in Healthcare Facilities in Washington, District of Columbia

OBJECTIVE Carbapenem-resistant Enterobacteriaceae (CRE) are a significant clinical and public health concern. Understanding the distribution of CRE colonization and developing a coordinated approach are key components of control efforts. The prevalence of CRE in the District of Columbia is unknown. We sought to determine the CRE colonization prevalence within healthcare facilities (HCFs) in the District of Columbia using a collaborative, regional approach. DESIGN Point-prevalence study. SETTING This study included 16 HCFs in the District of Columbia: all 8 acute-care hospitals (ACHs), 5 of 19 skilled nursing facilities, 2 (both) long-term acute-care facilities, and 1 (the sole) inpatient rehabilitation facility. PATIENTS Inpatients on all units excluding psychiatry and obstetrics-gynecology. METHODS CRE identification was performed on perianal swab samples using real-time polymerase chain reaction, culture, and antimicrobial susceptibility testing (AST). Prevalence was calculated by facility and unit type as the number of patients with a positive result divided by the total number tested. Prevalence ratios were compared using the Poisson distribution. RESULTS Of 1,022 completed tests, 53 samples tested positive for CRE, yielding a prevalence of 5.2% (95% CI, 3.9%-6.8%). Of 726 tests from ACHs, 36 (5.0%; 95% CI, 3.5%-6.9%) were positive. Of 244 tests from long-term-care facilities, 17 (7.0%; 95% CI, 4.1%-11.2%) were positive. The relative prevalence ratios by facility type were 0.9 (95% CI, 0.5-1.5) and 1.5 (95% CI, 0.9-2.6), respectively. No CRE were identified from the inpatient rehabilitation facility. CONCLUSION A baseline CRE prevalence was established, revealing endemicity across healthcare settings in the District of Columbia. Our study establishes a framework for interfacility collaboration to reduce CRE transmission and infection. Infect Control Hosp Epidemiol 2017;38:921-929.

Carbapenem-resistant Klebsiella pneumoniae in Barbados: Driving change in practice at the national level

Introduction

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is of growing concern globally. The risk for transmission of antimicrobial resistant organisms across several continents to the Caribbean is a real one given its tourism industry. After a cluster of cases of CRKP were detected, several studies detailed in this report were initiated to better characterize the problem.

Methods

A hospital-wide point prevalence study and active surveillance were performed at Queen Elizabeth Hospital (QEH) in Barbados in 2013 to assess the prevalence of CRKP infection/colonization. Following this, a 1-year longitudinal study measured the prevalence of CRKP isolates in the hospital and across all healthcare facilities in the country.

Results

In 2013, eleven viable isolates of CRKP from cluster of cases were sent for molecular epidemiology studies. When sequenced, they were found to be the ST-258 clone. Identification of a cluster of cases of CRKP ST-258/512 clones indicated person-to-person transmission. In September 2013, the hospital-wide point prevalence study revealed 18% of patients (53/299) at the hospital were either colonized or infected with CRKP. The infection to colonization ratio was 1:7. Patients who were infected/colonized vs. non-colonized were older (64.7 vs. 48.7 years, p<0.0001), were hospitalized longer (42.5 days vs. 27 days, p = 0.0042), were more likely to have an invasive device (66% vs. 32%, p<0.0001), especially urinary catheters (55% vs. 24%, p<0.0001), and were more likely to have used antimicrobials within the prior 14 days (91% vs. 46%, p<0.0001). Specific antimicrobials, including fluoroquinolones and piperacillin-tazobactam, were significantly associated with infection/colonization. In 2014, the 12-month period prevalence of CRKP in Barbados was 49.6 per 100,000 population and of blood stream infections was 3.2 per 100,000 population.

Conclusions

This point prevalence study identified patients at-risk of acquisition of CRKP and allowed QEH to implement interventions aimed at decreasing the prevalence of CRKP. Organization of a National and regional Infection Prevention and Control Committee in 2014 aimed to strengthen antimicrobial resistance surveillance programs across the English-speaking Caribbean were established.

Evaluation of a real-time PCR assay for rectal screening of OXA-48-producing Enterobacteriaceae in a general intensive care unit of an endemic hospital

Carbapenemase-producing Enterobacteriaceae are increasing worldwide. Rectal screening for these bacteria can inform the management of infected and colonized patients, especially those admitted to intensive care units (ICUs). A laboratory developed, qualitative duplex real-time polymerase chain reaction assay for rapid detection of OXA-48-like and VIM producing Enterobacteriaceae, performed on rectal swabs, was designed and evaluated in an intensive care unit with endemic presence of OXA-48. During analytical assay validation, no cross-reactivity was observed and 100% sensitivity and specificity were obtained for both bla_OXA-48-like and bla_VIM in all spiked clinical samples. During the clinical part of the study, the global sensitivity and specificity of the real-time PCR assay for OXA-48 detection were 95.7% and 100% (P=0.1250), respectively, in comparison with culture; no VIM-producing Enterobacteriaceae were detected. Clinical features of patients in the ICU who were colonized or infected with OXA-48 producing Enterobacteriaceae, including outcome, were analyzed. Most had severe underlying conditions, and had risk factors for colonization with carbapenemase-producing Enterobacteriaceae before or during ICU admission, such as receiving previous antimicrobial therapy, prior healthcare exposure (including long-term care), chronic disease, immunosuppression and/or the presence of an intravascular catheter and/or mechanical ventilation device. The described real-time PCR assay is fast (~2-3hours, if DNA extraction is included), simple to perform and results are easy to interpret, features which make it applicable in the routine of clinical microbiology laboratories. Implementation in endemic hospitals could contribute to early detection of patients colonized by OXA-48 producing Enterobacteriaceae and prevention of their spread.

Outbreak of Klebsiella pneumoniae carbapenemase-producing K pneumoniae: A systematic review

BACKGROUND

First detected in the United States in 1996, Klebsiella pneumoniae carbapenemase (KPC) has spread internationally among gram-negative bacteria, especially K pneumoniae. These microorganisms can cause serious infections in hospitalized patients, and there are few therapeutic options, culminating in increased mortality. The objective of this study was to describe the occurrence of outbreaks that were caused by KPC-producing K pneumoniae, emphasizing the interventions that were implemented to contain the outbreaks.

METHODS

PubMed, Web of Knowledge, and Literatura Latino Americana em Ciências da Saúde databases were searched for articles that were published between 2001 and 2012 according to the recommendations of Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

Of the 586 studies identified, 13 were selected for the final sample. Most studies showed that the containment of KPC outbreaks is possible in hospital settings through several actions, particularly use of surveillance cultures and the establishment of contact precautions.

CONCLUSIONS

The results show that limiting the cross-transmission of these and other KPC-producing bacteria is possible in a hospital setting. However, such isolates need to be detected early with the aid of culture surveillance and contained early using appropriate actions immediately to prevent an outbreak.

Evaluation of a Multiplex PCR Assay To Rapidly Detect Enterobacteriaceae with a Broad Range of β-Lactamases Directly from Perianal Swabs

We developed and evaluated multiplexed molecular beacon probes in a real-time PCR assay to identify prominent extended-spectrum-β-lactamase, plasmid-mediated AmpC β-lactamase (pAmpC) and carbapenemase genes directly from perianal swab specimens within 6 h. We evaluated this assay on 158 perianal swabs collected from hematopoietic stem cell transplant recipients and found that this assay was highly sensitive and specific for detection of CTX-M-, pAmpC-, and KPC-producing Enterobacteriaceae compared to culture on chromogenic agar.

Control of carbapenemase-producing Enterobacteriaceae outbreaks in acute settings: an evidence review

BACKGROUND

In recent years, infections with carbapenemase-producing Enterobacteriaceae (CPE) have been increasing globally and present a major public health challenge.

AIM

To review the international literature: (i) to describe CPE outbreaks in acute hospital settings globally; and (ii) to identify the control measures used during these outbreaks and report on their effectiveness.

METHODS

A systematic search of MEDLINE and EMBASE databases, abstract lists for key conferences and reference lists of key reviews was undertaken, and information on unpublished outbreaks was sought for 2000-2015. Where relevant, risk of bias was assessed using the Newcastle-Ottawa scale. A narrative synthesis of the evidence was conducted.

FINDINGS

Ninety-eight outbreaks were eligible. These occurred worldwide, with 53 reports from Europe. The number of cases (CPE infection or colonization) involved in outbreaks varied widely, from two to 803. In the vast majority of outbreaks, multi-component infection control measures were used, commonly including: patient screening; contact precautions (e.g. gowns, gloves); handwashing interventions; staff education or monitoring; enhanced environmental cleaning/decontamination; cohorting of patients and/or staff; and patient isolation. Seven studies were identified as providing the best-available evidence on the effectiveness of control measures. These demonstrated that CPE outbreaks can be controlled successfully using a range of appropriate, commonly used, infection control measures. However, risk of bias was considered relatively high for these studies.

CONCLUSION

The findings indicate that CPE outbreaks can be controlled using combinations of existing measures. However, the quality of the evidence base is weak and further high-quality research is needed, particularly on the effectiveness of individual infection control measures.

The growing threat of multidrug-resistant Gram-negative infections in patients with hematologic malignancies

Prolonged neutropenia and chemotherapy-induced mucositis render patients with hematologic malignancies highly vulnerable to Gram-negative bacteremia. Unfortunately, multidrug-resistant (MDR) Gram-negative bacteria are increasingly encountered globally, and current guidelines for empirical antibiotic coverage in these patients may not adequately treat these bacteria. This expansion of resistance, coupled with traditional culturing techniques requiring 2-4 days for bacterial identification and antimicrobial susceptibility results, have grave implications for these immunocompromised hosts. This review characterizes the epidemiology, risk factors, resistance mechanisms, recommended treatments, and outcomes of the MDR Gram-negative bacteria that commonly cause infections in patients with hematologic malignancies. We also examine the infection prevention strategies in hematology patients, such as infection control practices, antimicrobial stewardship, and targeted decolonization. Finally, we assess the strategies to improve outcomes of the infected patients, including gastrointestinal screening to guide empirical antibiotic therapy, new rapid diagnostic tools for expeditious identification of MDR pathogens, and use of two new antimicrobial agents, ceftolozane/tazobactam and ceftazidime/avibactam.

Carbapenem-Resistant Enterobacteriaceae Transmission in Health Care Facilities - Wisconsin, February-May 2015

Carbapenem-resistant Enterobacteriaceae (CRE) are multidrug-resistant gram-negative bacilli that can cause infections associated with high case fatality rates, and are emerging as epidemiologically important health care-associated pathogens in the United States (1). Prevention of CRE transmission in health care settings is dependent on recognition of cases, isolation of colonized and infected patients, effective use of infection control measures, and the correct use of antibiotics. The use of molecular technologies, including polymerase chain reaction (PCR) testing, pulsed-field gel electrophoresis (PFGE), and whole genome sequencing (WGS), can lead to detection of transmission events and interruption of transmission. In Wisconsin, acute care and critical access hospitals report laboratory-identified CRE to the Wisconsin Division of Public Health (WDPH), and clinical laboratories submit CRE isolates to the Wisconsin State Laboratory of Hygiene (WSLH) for molecular testing. During February-May 2015, a total of 49 CRE isolates from 46 patients were submitted to WSLH. On June 8, WSLH informed WDPH of five carbapenemase-producing CRE isolates with closely related PFGE patterns identified among four inpatients at two hospitals in southeastern Wisconsin. An investigation revealed a high degree of genetic relatedness among the patients' isolates, but did not identify the mechanism of transmission between the two facilities. No breaches in recommended practices were identified; after reviewing respiratory care procedures, no further cases were identified. Routine hospital- and laboratory-based surveillance can detect and prevent health care transmission of CRE.

Risk Factors for Carbapenemase-Producing Carbapenem-Resistant Enterobacteriaceae (CP-CRE) Acquisition Among Contacts of Newly Diagnosed CP-CRE Patients

OBJECTIVE Carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) are extremely drug-resistant pathogens. Screening of contacts of newly identified CP-CRE patients is an important step to limit further transmission. We aimed to determine the risk factors for CP-CRE acquisition among patients exposed to a CP-CRE index patient. METHODS A matched case-control study was performed in a tertiary care hospital in Israel. The study population was comprised of patients who underwent rectal screening for CP-CRE following close contact with a newly identified CP-CRE index patient. Cases were defined as positive tests for CP-CRE. For each case patient, 2 matched controls were randomly selected from the pool of contacts who tested negative for CP-CRE following exposure to the same index case. Bivariate and multivariate analyses were conducted using conditional logistic regression. RESULTS In total, 53 positive contacts were identified in 40 unique investigations (896 tests performed on 735 contacts) between October 6, 2008, and June 7, 2012. bla KPC was the only carbapenemase identified. In multivariate analysis, risk factors for CP-CRE acquisition among contacts were (1) contact with an index patient for ≥3 days (odds ratio [OR], 9.8; 95% confidence interval [CI], 2.0-48.9), (2) mechanical ventilation (OR, 4.1; 95% CI, 1.4-11.9), and (3) carriage or infection with another multidrug-resistant organism (MDRO; OR, 2.6; 95% CI, 1.0-7.1). Among patients who received antibiotics, cephalosporins were associated with a lower risk of acquisition. CONCLUSIONS Patient characteristics (ventilation and carriage of another MDRO) as well as duration of contact are risk factors for CP-CRE acquisition among contacts. The role of cephalosporins requires further study. Infect Control Hosp Epidemiol 2016;1-7.

Leveraging antimicrobial stewardship into improving rates of carbapenem-resistant Enterobacteriaceae

Carbapenem-resistant Enterobacteriaceae (CRE) are among the most critical threats facing our healthcare system and account for significant patient mortality. There is considerable interest in the development of new treatment strategies. However, less attention has been paid to reducing CRE infection rates. Antibiotic stewardship programs can be uniquely empowered to reduce widespread pathogen resistance and by extension, optimize patient care and lower healthcare costs.

Clinical and laboratory considerations for the rapid detection of carbapenem-resistant Enterobacteriaceae

Carbapenem resistance among the Enterobacteriaceae has become a significant clinical and public health dilemma. Rapid administration of effective antimicrobials and implementation of supplemental infection control practices is required to both improve patient outcomes and limit the spread of these highly resistant organisms. However, carbapenem-resistant Enterobacteriaceae (CRE)-infected patients are predominantly identified by routine culture methods, which take days to perform. Rapid genomic and phenotypic methods are currently available to accelerate the identification of carbapenemase-producing CRE. Effective use of these technologies is reliant on close collaboration between clinical microbiology, infection prevention, antimicrobial stewardship and infectious diseases specialists. This review discusses the performance characteristics of these technologies to date, and describes strategies for their optimal implementation.

Reactive Infection Control Strategy for Control of New Delhi Metallo-β-Lactamase (NDM)-Producing Enterobacteriaceae Analyzed Using Whole-Genome Sequencing: Hits and Misses

Genetically distinct isolates of New Delhi metallo-β-lactamase (NDM)-producing Enterobacteriaceae were identified from the clinical cultures of 6 patients. Screening of shared-ward contacts identified 2 additional NDM-positive patients. Phylogenetic analysis proved that 1 contact was a direct transmission while the other was unrelated to the index, suggesting hidden routes of transmission. Infect Control Hosp Epidemiol 2016;37:987-990.

What tuberculosis can teach us about combating multidrug-resistant Gram negative bacilli

There are striking similarities between the dual pandemics of multidrug-resistant tuberculosis (MDR TB) and multidrug-resistant Gram negative bacilli (MDR GNB) despite fundamental differences in the pathogenesis and epidemiology of these pathogens. In this perspective, we highlight several strategies that have been used by the global TB community to address the MDR TB problem, including approaches to: encourage appropriate use of anti-TB medications, enhance appropriate utilization of molecular diagnostic testing, facilitate development of new antimicrobial agents, and strengthen surveillance systems and infection control practices. Understanding the successes and challenges of these strategies for MDR TB control will be instructive for efforts to curb emergence and spread of MDR GNB.

Bloodstream infections in the Intensive Care Unit

Bloodstream infections (BSIs) represent a common complication among critically ill patients and a leading cause of morbidity and mortality. The prompt initiation of an effective antibiotic therapy is necessary in order to reduce mortality and to improve clinical outcomes. However, the choice of the empiric antibiotic regimen is often challenging, due to the worldwide spread of multi-drug resistant (MDR) organisms with reduced susceptibility to the available broad-spectrum antimicrobials. New therapeutic strategies are 5 to improve the effectiveness of antibiotic treatment while minimizing the risk of resistance selection.

Carbapenem-resistant enterobacteriaceae: occult threat in the intensive care unit

Carbapenem-resistant Enterobacteriaceae are a group of virulent, drug-resistant gram-negative bacteria that are increasingly the cause of infection. Such infections are associated with a high morbidity and mortality and increased health care costs. Management of these infections requires recognition of patients at risk for multidrug-resistant microbial colonization and infections, identification of the causative organism, and rapid, appropriate treatment. Lack of awareness of proper isolation of patients harboring these organisms and delay in prescribing antibiotics such as tigecycline and polymyxins contribute to the spread of infection in intensive care units. Surveillance and infection control measures are paramount in preventing outbreaks of infection caused by carbapenem-resistant Enterobacteriaceae. Critical care nurses are in a vital position to monitor patients at risk for such infections and to promote infection prevention measures.

The Widespread Presence of a Multidrug-Resistant Escherichia coli ST131 Clade among Community-Associated and Hospitalized Patients

BACKGROUND & AIMS

The extent of entry of multidrug-resistant Escherichia coli from the community into the hospital and subsequent clonal spread amongst patients is unclear. To investigate the extent and direction of clonal spread of these bacteria within a large teaching hospital, we prospectively genotyped multidrug-resistant E. coli obtained from community- and hospital associated patient groups and compared the distribution of diverse genetic markers.

METHODS

A total of 222 E. coli, classified as multi-drug resistant according to national guidelines, were retrieved from both screening (n = 184) and non-screening clinical cultures (n = 38) from outpatients and patients hospitalized for various periods. All isolates were routinely genotyped using an amplified fragment length polymorphism (AFLP) assay and real-time PCR for CTX-M genes. Multi-locus sequence typing was additionally performed to confirm clusters. Based on demographics, patients were categorized into two groups: patients that were not hospitalized or less than 72 hours at time of strain isolation (group I) and patients that were hospitalized for at least 72 hours (group II).

RESULTS

Genotyping showed that most multi-drug resistant E. coli either had unique AFLP profiles or grouped in small clusters of maximally 8 isolates. We identified one large ST131 clade comprising 31% of all isolates, containing several AFLP clusters with similar profiles. Although different AFLP clusters were found in the two patient groups, overall genetic heterogeneity was similar (35% vs 28% of isolates containing unique AFLP profiles, respectively). In addition, similar distributions of CTX-M groups, including CTX-M 15 (40% and 44% of isolates in group I and II, respectively) and ST131 (32% and 30% of isolates, respectively) were found.

CONCLUSION

We conclude that multi-drug resistant E. coli from the CTX-M 15 associated lineage ST131 are widespread amongst both community- and hospital associated patient groups, with similar genetic diversity and similar distributions of genetic markers.

Screening of nursing home residents for colonization with carbapenem-resistant Enterobacteriaceae admitted to acute care hospitals: Incidence and risk factors

BACKGROUND

There are increasing reports of multidrug-resistant gram-negative bacilli in nursing homes and acute care hospitals.

METHODS

We performed a point prevalence survey to detect fecal carriage of gram-negative bacteria carrying carbapenem resistance genes or which were otherwise resistant to carbapenem antibiotics among 500 consecutive admissions from local nursing homes to 2 hospitals in Providence, Rhode Island. We performed a case-control study to identify risk factors associated with carriage of carbapenem-resistant Enterobacteriaceae (CRE).

RESULTS

There were 404 patients with 500 hospital admissions during which they had rectal swab samples cultured. Fecal carriage of any carbapenem-resistant or carbapenemase- producing gram-negative bacteria was found in 23 (4.6%) of the 500 hospital admissions, including 7 CRE (1.4%), 2 (0.4%) of which were Klebsiella pneumoniae carbapenemase (ie, blaKPC) producing (CPE) Citrobacter freundii, 1 of which was carbapenem susceptible by standard testing methods. Use of a gastrostomy tube was associated with CRE carriage (P = .04). We demonstrated fecal carriage of carbapenem-resistant or carbapenemase-producing gram-negative bacteria in 4.6% of nursing home patients admitted to 2 acute care hospitals, but only 0.4% of such admissions were patients with fecal carriage of CPE. Use of gastrostomy tubes was associated with fecal carriage of gram-negative bacteria with detectable carbapenem resistance.

CONCLUSION

CRE fecal carriage is uncommon in our hospital admissions from nursing homes.

Predictors of Persistent Carbapenem-Resistant Enterobacteriaceae Carriage upon Readmission and Score Development

BACKGROUND

Carriers of carbapenem-resistant Enterobacteriaceae (CRE) are often readmitted, exposing patients to CRE cross-transmission.

OBJECTIVE

To identify predictors of persistent CRE carriage upon readmission, directing a risk prediction score.

DESIGN

Retrospective cohort study.

SETTING

University-affiliated general hospital.

PATIENTS

A cohort of 168 CRE carriers with 474 readmissions.

METHODS

The primary and secondary outcomes were CRE carriage status at readmission and length of CRE carriage. Predictors of persistent CRE carriage upon readmission were analyzed using a generalized estimating equations (GEE) multivariable model. Readmissions were randomly divided into derivation and validation sets. A CRE readmission score was derived to predict persistent CRE carriage in 3 risk groups: high, intermediate, and low. The discriminatory ability of the model and the score were expressed as C statistics.

RESULTS

CRE carrier status persisted for 1 year in 33% of CRE carriers. Positive CRE status was detected in 202 of 474 readmissions (42.6%). The following 4 variables were associated with persistent CRE carriage at readmission: readmission within 1 month (odds ratio [OR], 6.95; 95% confidence interval [CI], 2.79–17.30), positive CRE status on preceding admission (OR, 5.46; 95% CI, 3.06–9.75), low Norton score (OR, 3.07; 95% CI, 1.26–7.47), and diabetes mellitus (OR, 1.84; 95% CI, 0.98–3.44). The C statistics were 0.791 and 0.789 for the derivation set (n=322) model and score, respectively, and the C statistic was 0.861 for the validation set of the score (n=152). The rates of CRE carriage at readmissions (validation set) for the groups with low, intermediate, and high scores were 8.6%, 38.9%, and 77.6%, respectively.

CONCLUSIONS

CRE carrier state commonly persists upon readmission, and this risk can be estimated to guide screening policy and infection control measures.

Infect. Control Hosp. Epidemiol. 2016;37(2):188–196

Hospital Readmissions in Patients With Carbapenem-Resistant Klebsiella pneumoniae

BACKGROUND

Various transmission routes contribute to spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) in hospitalized patients. Patients with readmissions during which CRKP is again isolated ("CRKP readmission") potentially contribute to transmission of CRKP.

OBJECTIVE

To evaluate CRKP readmissions in the Consortium on Resistance against Carbapenems in K. pneumoniae (CRaCKLe).

DESIGN

Cohort study from December 24, 2011, through July 1, 2013.

SETTING

Multicenter consortium of acute care hospitals in the Great Lakes region.

PATIENTS

All patients who were discharged alive during the study period were included. Each patient was included only once at the time of the first CRKP-positive culture.

METHODS

All readmissions within 90 days of discharge from the index hospitalization during which CRKP was again found were analyzed. Risk factors for CRKP readmission were evaluated in multivariable models.

RESULTS

Fifty-six (20%) of 287 patients who were discharged alive had a CRKP readmission. History of malignancy was associated with CRKP readmission (adjusted odds ratio [adjusted OR], 3.00 [95% CI, 1.32-6.65], P<.01). During the index hospitalization, 160 patients (56%) received antibiotic treatment against CRKP; the choice of regimen was associated with CRKP readmission (P=.02). Receipt of tigecycline-based therapy (adjusted OR, 5.13 [95% CI, 1.72-17.44], using aminoglycoside-based therapy as a reference in those treated with anti-CRKP antibiotics) was associated with CRKP readmission.

CONCLUSION

Hospitalized patients with CRKP-specifically those with a history of malignancy-are at high risk of readmission with recurrent CRKP infection or colonization. Treatment during the index hospitalization with a tigecycline-based regimen increases this risk.

Outbreak of colonization by carbapenemase-producing Klebsiella pneumoniae in a neonatal intensive care unit: Investigation, control measures and assessment

We describe an outbreak of carbapenemase-producing Klebsiella pneumoniae in a neonatal intensive care unit and assess the effect of infection control measures. Our assessment indicates that active surveillance culture is very useful in identifying multidrug-resistant organisms and its prevention from transmission. Besides contact precaution, environment disinfection, good compliance of hand hygiene, and single-room isolation is very important for preventing transmission of carbapenemase-producing K pneumoniae isolates.

Diffusion and transmission of carbapenem-resistant Klebsiella pneumoniae in the medical and surgical wards of a university hospital in Milan, Italy

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is emerging as a public health problem worldwide. In Italy, a remarkable increase in CRKP cases has been reported since 2010. In this study, CRKP diffusion, distribution and in-hospital transmission trends were evaluated in a university hospital in Milan, Italy, from January 2012 to December 2013. Isolates from 63 newly detected CRKP-positive patients were genotyped, and possible transmission was determined by combining the molecular results with data concerning the patients' admission and in-hospital transfers. Most of the cases (90.4%) were from general medical and surgery wards, and the remaining 9.6% were from the intensive care unit. Fifteen of the 46 hospital-associated cases (32.6%) were attributable to in-hospital transmission. After the introduction of targeted and hospital-wide control measures, the transmission index significantly decreased from 0.65 to 0.13 (p=0.01). There was also a decrease in the overall nosocomial case incidence, from 0.37 to 0.17 per 1000 person-days (p=0.07). Our findings indicate that the spread of CRKP in Northern Italy hospitals may go far beyond high-risk settings (i.e., intensive care units) and that strict surveillance should be extended to general areas of care.

Risk factors for acquisition of carbapenem resistant Enterobacteriaceae in an acute tertiary care hospital in Singapore

Background

Carbapenem resistant Enterobacteriaceae (CRE) is increasingly reported worldwide. A similar increase is seen in Singapore since identification of its first case in 2008. The aim of this study was to identify local risk factors for carriage of CRE in patients from an acute tertiary care hospital in Singapore.

Method

A matched case-control study was conducted on inpatients treated from January 1, 2011 till December 31, 2013. Two hundred and three cases of CRE infection or colonization were matched with 203 controls. CRE types were identified by PCR. Statistical analysis of data including a multivariate logistic regression analysis was done using SPSS 21.0.

Results

CREs were commonly seen in Klebsiella pneumoniae (42.2 %), Escherichia coli (24.3 %) and Enterobacter cloacae complex (17.2 %) in the 268 isolates. NDM-1 was the commonest CRE type seen (44.4 %), followed by KPC (39.9 %) whilst OXA-48 only constituted (7.8 %). Univariate analysis identified key risk factors associated with CRE as history of previous overseas hospitalization (OR: 33.667; 95 % CI: 4.539-259.700), admission to ICU (OR: 11.899; 95 % CI: 4.986-28.399) and HD/ICA (OR: 6.557; 95 % CI: 4.057-10.596); whilst a multivariate analysis revealed exposure to antibiotics penicillin (OR: 4.640; 95 % CI: 1.529-14.079] and glycopeptide (OR: 5.162; 95 % CI: 1.377-19.346) and presence of central line device (OR: 3.117; 95 % CI: 1.167-8.330) as significant independent predictors.

Conclusions

The identification of risk factors amongst our local population helped to refine the criteria used for target active surveillance screening for CRE amongst inpatients at time of hospital admission.

Residence in Skilled Nursing Facilities Is Associated with Tigecycline Nonsusceptibility in Carbapenem-Resistant Klebsiella pneumoniae

OBJECTIVE

To determine the rates of and risk factors for tigecycline nonsusceptibility among carbapenem-resistant Klebsiella pneumoniae (CRKPs) isolated from hospitalized patients.

DESIGN

Multicenter prospective observational study.

SETTING

Acute care hospitals participating in the Consortium on Resistance against Carbapenems in Klebsiella pneumoniae (CRaCKle).

PATIENTS

A cohort of 287 patients who had CRKPs isolated from clinical cultures during hospitalization.

METHODS

For the period from December 24, 2011 to October 1, 2013, the first hospitalization of each patient with a CRKP during which tigecycline susceptibility for the CRKP isolate was determined was included. Clinical data were entered into a centralized database, including data regarding pre-hospital origin. Breakpoints established by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) were used to interpret tigecycline susceptibility testing.

RESULTS

Of 287 patients included in the final cohort, 155 (54%) had tigecycline-susceptible CRKPs. Of all index isolates, 81 (28%) were tigecycline-intermediate and 51 (18%) were tigecycline resistant. In multivariate modeling, independent risk factors for tigecycline nonsusceptibility were (1) admission from a skilled nursing facility (OR, 2.51; 95% CI, 1.51-4.21; P=.0004), (2) positive culture within 2 days of admission (OR, 1.82; 95% CI, 1.06-3.15; P=.03), and (3) receipt of tigecycline within 14 days (OR, 4.38, 95% CI, 1.37-17.01, P=.02).

CONCLUSIONS

In hospitalized patients with CRKPs, tigecycline nonsusceptibility was more frequently observed in those admitted from skilled nursing facilities and occurred earlier during hospitalization. Skilled nursing facilities are an important target for interventions to decrease antibacterial resistance to antibiotics of last resort for treatment of CRKPs.

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.

Risk Factors for Recurrence of Carbapenem-Resistant Enterobacteriaceae Carriage: Case-Control Study

BACKGROUND

The natural history of carbapenem-resistant Enterobacteriaceae (CRE) carriage and the timing and procedures required to safely presume a CRE-free status are unclear.

OBJECTIVE

To determine risk factors for recurrence of CRE among presumed CRE-free patients.

METHODS

Case-control study including CRE carriers in whom CRE carriage presumably ended, following at least 2 negative screening samples on separate days. Recurrence of CRE carriage was identified through clinical samples and repeated rectal screening in subsequent admissions to any healthcare facility in Israel. Patients with CRE recurrence (cases) were compared with recurrence-free patients (controls). The duration of follow-up was 1 year for all surviving patients.

RESULTS

Included were 276 prior CRE carriers who were declared CRE-free. Thirty-six persons (13%) experienced recurrence of CRE carriage within a year after presumed eradication. Factors significantly associated with CRE recurrence on multivariable analysis were the time in months between the last positive CRE sample and presumed eradication (odds ratio, 0.94 [95% CI, 0.89–0.99] per month), presence of foreign bodies at the time of presumed eradication (4.6 [1.64–12.85]), and recurrent admissions to healthcare facilities during follow-up (3.15 [1.05–9.47]). The rate of CRE recurrence was 25% (11/44) when the carrier status was presumed to be eradicated 6 months after the last known CRE-positive sample, compared with 7.5% (10/134) if presumed to be eradicated after 1 year.

CONCLUSIONS

We suggest that the CRE-carrier status be maintained for at least 1 year following the last positive sample. Screening of all prior CRE carriers regardless of current carriage status is advised.

Infect. Control Hosp. Epidemiol. 2015;36(8):936–941

A national intervention to prevent the spread of carbapenem-resistant Enterobacteriaceae in Israeli post-acute care hospitals

OBJECTIVE

Patients hospitalized in post-acute care hospitals (PACHs) constitute an important reservoir of antimicrobial-resistant bacteria. High carriage prevalence of carbapenem-resistant Enterobacteriaceae (CRE) has been observed among patients hospitalized in PACHs. The objective of the study is to describe the impact of a national infection control intervention on the prevalence of CRE in PACHs.

DESIGN

A prospective cohort interventional study.

SETTING

Thirteen PACHs in Israel.

INTERVENTION

A multifaceted intervention was initiated between 2008 and 2011 as part of a national program involving all Israeli healthcare facilities. The intervention has included (1) periodic on-site assessments of infection control policies and resources, using a score comprised of 16 elements; (2) assessment of risk factors for CRE colonization; (3) development of national guidelines for CRE control in PACHs involving active surveillance and contact isolation of carriers; and (4) 3 cross-sectional surveys of rectal carriage of CRE that were conducted in representative wards.

RESULTS

The infection control score increased from 6.8 to 14.0 (P < .001) over the course of the study period. A total of 3,516 patients were screened in the 3 surveys. Prevalence of carriage among those not known to be carriers decreased from 12.1% to 7.9% (P = .008). Overall carrier prevalence decreased from 16.8% to 12.5% (P = .013). Availability of alcohol-based hand rub, appropriate use of gloves, and a policy of CRE surveillance at admission to the hospital were independently associated with lower new carrier prevalence.

CONCLUSION

A nationwide infection control intervention was associated with enhanced infection control measures and a reduction in the prevalence of CRE in PACHs.

Strategic measures for the control of surging antimicrobial resistance in Hong Kong and mainland of China

Antimicrobial-resistant bacteria are either highly prevalent or increasing rapidly in Hong Kong and China. Treatment options for these bacteria are generally limited, less effective and more expensive. The emergence and dynamics of antimicrobial resistance genes in bacteria circulating between animals, the environment and humans are not entirely known. Nonetheless, selective pressure by antibiotics on the microbiomes of animal and human, and their associated environments (especially farms and healthcare institutions), sewage systems and soil are likely to confer survival advantages upon bacteria with antimicrobial-resistance genes, which may be further disseminated through plasmids or transposons with integrons. Therefore, antibiotic use must be tightly regulated to eliminate such selective pressure, including the illegalization of antibiotics as growth promoters in animal feed and regulation of antibiotic use in veterinary practice and human medicine. Heightened awareness of infection control measures to reduce the risk of acquiring resistant bacteria is essential, especially during antimicrobial use or institutionalization in healthcare facilities. The transmission cycle must be interrupted by proper hand hygiene, environmental cleaning, avoidance of undercooked or raw food and compliance with infection control measures by healthcare workers, visitors and patients, especially during treatment with antibiotics. In addition to these routine measures, proactive microbiological screening of hospitalized patients with risk factors for carrying resistant bacteria, including history of travel to endemic countries, transfer from other hospitals, and prolonged hospitalization; directly observed hand hygiene before oral intake of drugs, food and drinks; and targeted disinfection of high-touch or mutual-touch items, such as bed rails and bed curtains, are important. Transparency of surveillance data from each institute for public scrutiny provides an incentive for controlling antimicrobial resistance in healthcare settings at an administrative level.

Predictors of Rectal Carriage of Carbapenem-Resistant Enterobacteriaceae (CRE) among Patients with Known CRE Carriage at Their Next Hospital Encounter

Background.

Carbapenem-resistant Enterobacteriaceae (CRE) are important extremely drug-resistant pathogens that have emerged during the past decade. Early identification and isolation of carriers are key components of an effective infection control strategy in healthcare facilities. Very little is known about the natural history of CRE carriage. We aimed to determine the predictors of a positive CRE rectal screen test among patients with known CRE carriage screened at their next hospital encounter.

Methods.

A case-control study was conducted. Sixty-six patients who tested positive for CRE carriage were surveyed for CRE rectal carriage at the next hospital encounter; screen-positive patients were compared with screen-negative control patients. Data were extracted from the patients' medical records and from the hospital computerized database.

Results.

Twenty-three case patients and 43 control patients were identified. Predictors for a positive CRE rectal carriage test were (1) prior fluoroquinolone use (odds ratio [OR], 4.27; 95% confidence interval [CI], 1.10–16.6), (2) admission from an institution or another hospital (OR, 4.04; 95% CI, 1.33–12.37), and (3) time interval less than or equal to 3 months since the first positive CRE test (OR, 3.59; 95% CI, 1.24–10.37). Among patients with no predictor variables, the likelihood of having a positive screen test at the next hospital encounter was 1/7. If they had at least 1 predictor, the likelihood increased to 1/2.

Conclusions.

Prior fluoroquinolone use, transfer from another healthcare facility, and admission less than or equal to 3 months since the first CRE isolation are predictors of persistent CRE rectal carriage. These predictors can be used in designing CRE prevention strategies.

Risk factors for colonization due to carbapenem-resistant Enterobacteriaceae among patients exposed to long-term acute care and acute care facilities

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical microbiology costs for methods of active surveillance for Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae

OBJECTIVE

To compare direct laboratory costs of different methods for perirectal screening for carbapenemase-producing Enterobacteriaceae (CPE) colonization.

DESIGN

Cost-benefit analysis.

SETTING

A university hospital and affiliated long-term acute care hospital (LTACH).

PARTICIPANTS

Inpatients from the hospital or LTACH.

METHODS

Perirectal samples were collected from inpatients at risk for exposure to CPE. In 2009, we compared the accuracy of the Centers for Disease Control and Prevention (CDC)-recommended CPE screening method with similar methods incorporating a chromogenic agar (CA). We then performed a cost projection analysis using 2012 screening results for the CA method, the CDC method, and a molecular assay with wholesale pricing based on the 2009 analysis. Comparisons of turnaround and personnel time were also performed.

RESULTS

A total of 185 (2.7%) of 6,860 samples were confirmed as CPE positive during 2012. We previously found that the CDC protocol had a lower sensitivity than the CA method and predicted that the CDC protocol would have missed 92 of the CPE-positive screening results, whereas the modified protocol using CA would have missed 26, assuming similar prevalence and performance. Turnaround time was 3 days using the CDC and CA-modified protocols compared with 1 day for molecular testing. The estimated annual total program cost and total technologist's hours would be the following: CA-modified protocol, $37,441 and 376 hours; CDC protocol, $22,818 and 482 hours; and molecular testing, $224,596 and 343 hours.

CONCLUSIONS

The CDC screening protocol appeared to be the least expensive perirectal screening method. However, expense must be weighed against a lower sensitivity and extra labor needed for additional work-up of non-CPE isolates. The molecular test has the shortest turnaround time but the greatest expense.

Control of carbapenemase-producing Klebsiella pneumoniae: a region-wide intervention

Starting in 2010, there was a sharp increase in infections caused by Klebsiella pneumoniae resistant to carbapenems in the Emilia-Romagna region in Italy. A region-wide intervention to control the spread of carbapenemase-producing K. pneumoniae (CPKP) in Emilia-Romagna was carried out, based on a regional guideline issued in July 2011. The infection control measures recommended to the Health Trusts (HTs) were: phenotypic confirmation of carbapenemase production, active surveillance of asymptomatic carriers and contact isolation precautions for carriers. A specific surveillance system was activated and the implementation of control measures in HTs was followed up. A significant linear increase of incident CPKP cases over time (p<0.001) was observed at regional level in Emilia-Romagna in the pre-intervention period, while the number of cases remained stable after the launch of the intervention (p=0.48). Considering the patients hospitalised in five HTs that provided detailed data on incident cases, a downward trend was observed in incidence after the release of the regional guidelines (from 32 to 15 cases per 100,000 hospital patient days). The spread of CPKP in Emilia-Romagna was contained by a centrally-coordinated intervention. A further reduction in CPKP rates might be achieved by increased compliance with guidelines and specific activities of antibiotic stewardship.

Carbapenem-resistant Enterobacteriaceae: biology, epidemiology, and management

Introduced in the 1980s, carbapenem antibiotics have served as the last line of defense against multidrug-resistant Gram-negative organisms. Over the last decade, carbapenem-resistant Enterobacteriaceae (CRE) have emerged as a significant public health threat. This review summarizes the molecular genetics, natural history, and epidemiology of CRE and discusses approaches to prevention and treatment.

Outcomes of carbapenem-resistant Enterobacteriaceae isolation: matched analysis

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) isolation is associated with poor outcomes. The matched cohort study design enables investigation of specific role of resistance in contributing to patients' outcomes. Patients with CRE were matched to 3 groups: (1) patients with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL), (2) patients with carbapenem-susceptible non-ESBL Enterobacteriaceae, and (3) uninfected controls.

METHODS

Patients with CRE isolated at Detroit Medical Center (September 1, 2008, to August 31, 2009) were matched (1:1 ratio) to the 3 groups based on (1) bacteria type, (2) hospital/facility, (3) unit/clinic, (4) calendar year, and (5) time at risk (ie, from admission to culture). Multivariable logistic regression models for outcomes were constructed.

RESULTS

Ninety-one patients with CRE were enrolled. CRE isolation was not an independent predictor for in-hospital mortality in any of the models (ie, vs uncolonized controls, vs ESBL, vs non-ESBL Enterobacteriaceae, and vs all 3 non-CRE groups combined), despite high significance of association in bivariate analyses. CRE isolation was independently associated with deterioration in functional status [odds ratio, 9; P = .002] and being discharged to a long-term care facility after being admitted to the hospital from home [odds ratio, 13.7; P < .001].

CONCLUSION

Underlying condition and comorbidities are the principal factors responsible for in-hospital mortality in CRE infections; however, in-hospital mortality is not independently correlated to the offending pathogen. In addition, we found that the pathogen contributes significantly to patients' degree of morbidity.

Limiting and controlling carbapenem-resistant Klebsiella pneumoniae

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is resistant to almost all antimicrobial agents, is associated with substantial morbidity and mortality, and poses a serious threat to public health. The ongoing worldwide spread of this pathogen emphasizes the need for immediate intervention. This article reviews the global spread and risk factors for CRKP colonization/infection, and provides an overview of the strategy to combat CRKP dissemination.