Epidemiology Of Vancomycin-resistant Enterococci Research Articles

Vancomycin-Resistant Enterococcus in Hematology-Oncology Patients: a Review on Colonization, Screening, Infections, Resistance, and Antimicrobial Stewardship

Vancomycin-resistant enterococcus (VRE) has emerged as a pathogen causing significant morbidity and mortality in immunocompromised patients in past decades. This article summarizes current literature on the epidemiology of VRE in hematology-oncology patients. It examines the associations between infection control practices, prescribing behavior, colonization, and infections due to VRE in patients with acute leukemia and stem cell transplant recipients. It also explores opportunities for antimicrobial stewardship and future research. VRE colonization is associated with VRE infections, but the progression from colonization to infection is not well defined. Colonization pressure may be associated with infection control practices at the patient unit level. Although previous data showed that environmental control may reduce the risk of VRE colonization in hematology-oncology patients, recent changes in contact precautions policies in some institutions could be associated with increased colonization pressure. Risk factors for VRE infections, particularly bacteremia, include exposure to broad-spectrum antibiotics, such as carbapenems, and neutropenia. Routine empiric use of anti-VRE antibiotics has not been shown to improve clinical outcomes, and itself could be a driver for VRE resistance. The majority of existing data are limited to single-centered, retrospective cohort studies, with before-and-after design being the most common. Without appropriate comparator groups, the results are subject to bias. Prospectively collected data with appropriate control groups will improve our understanding of the contributing factors to VRE infections, and the role antimicrobial stewardship plays.

Novel Strategies for the Management of Vancomycin-Resistant Enterococcal Infections.

Vancomycin-resistant enterococci (VRE) are important nosocomial pathogens that commonly affect critically ill patients. VRE have a remarkable genetic plasticity allowing them to acquire genes associated with antimicrobial resistance. Therefore, the treatment of deep-seated infections due to VRE has become a challenge for the clinician. The purpose of this review is to assess the current and future strategies for the management of recalcitrant deep-seated VRE infections and efforts for infection control in the hospital setting. Preventing colonization and decolonization of multidrug-resistant bacteria are becoming the most promising novel strategies to control and eradicate VRE from the hospital environment. Fecal microbiota transplantation (FMT) has shown remarkable results on treating colonization and infection due to Clostridiodes difficille and VRE, as well as to recover the integrity of the gut microbiota under antibiotic pressure. Initial reports have shown the efficacy of FMT on reestablishing patient microbiota diversity in the gut and reducing the dominance of VRE in the gastrointestinal tract. In addition, the use of bacteriophages may be a promising strategy in eradicating VRE from the gut of patients. Until these strategies become widely available in the hospital setting, the implementation of infection control measures and stewardship programs are paramount for the control of this pathogen and each program should provide recommendations for the proper use of antibiotics and develop strategies that help to detect populations at risk of VRE colonization, prevent and control nosocomial transmission of VRE, and develop educational programs for all healthcare workers addressing the epidemiology of VRE and the potential impact of these pathogens on the cost and outcomes of patients. In terms of antibiotic strategies, daptomycin has become the standard of care for the management of deep-seated infections due to VRE. However, recent evidence indicates that the efficacy of this antibiotic is limited, and higher (10-12mg/kg) doses and/or combination with β-lactams is needed for therapeutic success. Clinical data to support the best use of daptomycin against VRE are urgently needed. This review provides an overview of recent developments regarding the prevention, treatment, control, and eradication of VRE in the hospital setting. We aim to provide an update of the most recent therapeutic strategies to treat deep-seated infections due to VRE.

Emergence of vancomycin-resistant enterococci in Switzerland: a nation-wide survey

This nation-wide survey on the epidemiology of vancomycin-resistant enterococci (VRE) included 142 healthcare institutions and showed an increasing number of VRE colonizations and infections in Switzerland, probably for the most part due to nosocomial dissemination. The introduction and spread of a new clone, gaps in VRE screening policies as well as heterogeneity regarding the management of VRE clusters may be possible explanations.

Epidemiology of Vancomycin-Resistant Enterococci in Various Medical Wards

Background. Vancomycin-resistant enterococci (VRE) have become one of the leading cause of health care-associated infections. Data on occurrence and spread of these pathogens in different types of hospital units are needed to develop effective surveillance and control measures to prevent dissemination of VRE. Aim. The aim of this study was to define hospital units with high risk of VRE dissemination in health care facilities of St. Petersburg. Materials and Methods. Point-prevalence study of colonisation and infection in patients and contamination of the environment was conducted during 2013 - 2014 in 8 hospital units of different types: neonatal intensive care, newborn pathology, general paediatric surgery, bone marrow transplantation (BMT for adolescents), cancer surgery of the gastrointestinal (GI) tract and breast cancer, haemodialysis (three units). In each unit microbiological testing of clinical (N=857) and environmental (N=508) samples was conducted three times a months during the study period. Verification of vancomycin resistance in enterococci was conducted by amplification of vanA and vanB cassettes according to the technique developed by S. Dutka-Malen et al. Molecular genetic typing of enterococci by random amplification of polymorphic DNA (RAPD-PCR) was performed with universal primer R5 (5’-AACGCGCAAC-3’) in the concentration of 50 pmol/^L, according to the protocol proposed by B. Martin et al. VNTR analysis was performed according to the technique published by J. Top et al. Results. Colonization of patients and contamination of environment by VRE were detected only in haemato-oncologyunits (21,6 per 100 patients, 2,6 per 100 environmental swabs), neonatal intensive care (16,7 per 100 patients, 8,5 per 100 environmental swabs), and newborn pathology (34,6 per 100 patients, 3,3 per 100 environmental swabs). VRE were detected on the related to patient care environmental objects in common use for all patients (scales, changing tables, procedure tables, sink faucets) in the neonatal intensive care units and non-medical objects shared by all patients (tables in patient rooms, microwave oven and refrigerators shelves) in the haemato-oncology unit. The molecular genetic typing showed that strains of VRE isolated from patients and the environment were identical. Vancomycin resistance due to presence of vanA was dominating. Conclusion. Neonatal and haemato-oncology departments were identified as high risk hospital units. The most common mode of transmission of VRE is contact transmission via hands of health care workers in neonatal units and via environmental objects in haemato-oncology. To contain dissemination of VRE in the high risk units, development of microbiological monitoring of VRE and measures to control their transmission is needed.

Molecular epidemiology of vancomycin resistant enterococci in a tertiary care hospital in Saudi Arabia

AimVancomycin-resistant enterococci (VRE) are a major cause of nosocomial infections with high mortality and morbidity. There is limited data on the molecular characterization of VRE in Saudi Arabia. This study was carried out to investigate the premise that a shift in VRE epidemiology is occurring in our setting. MethodsEnterococcus species identification and susceptibility testing plus VRE phenotypic confirmation by vancomycin and teicoplanin E-test were carried out. Vancomycin resistance genes were detected by PCR. Strain typing was conducted using PFGE. ResultsAmong the strains of Enterococcus spp. investigated in this study, 17 (4.5%) were VRE. With the exception of one isolate from rectal swab, all others were clinical specimens with blood being the commonest source (n = 11; 64.7%), followed by urine (n = 3; 17.6%). The 17 VRE isolates were Enterococcus faecium (n/N = 13/17) and Enterococcus gallinarum (n/N = 4/17). Among E. faecium isolates, vanA+/vanB+ (n/N = 8/13; 62%) exhibiting VanB phenotype were predominant. One of the five vanA+E. faecium isolates exhibited a VanB phenotype indicative of vanA genotype-VanB phenotype incongruence. E. gallinarum isolates exhibited a Van C phenotype although two were vanA+/vanC1+. PFGE revealed a polyclonal distribution with eight pulsotypes. ConclusionThese findings indicate an evolving VRE epidemiology with vanA+/vanB+ isolates and vanA genotype-VanB phenotype incongruence isolates, which were previously described as colonizers, are now causing clinical infection.

Epidemiology of vancomycin-resistant enterococci in postacute care facility and predictors of clearance: A 5-year retrospective cohort study

BackgroundThere have been no local studies on the duration and risk factors for vancomycin-resistant enterococcus (VRE) colonization in a postacute convalescence hospital. Our aim was to investigate the duration of VRE colonization and risk factors for prolonged carriage among patients admitted to a convalescence hospital. MethodsThe case records of patients admitted to a 400-bed convalescence care hospital with rectal swab or stool culture samples positive for VRE from January 2010 to December 2014 were retrieved. The clinical characteristics associated with clearance of colonization within the hospitalization period were analyzed, and logistic regression was set up to detect for factors associated with inpatient and 1-year mortality. ResultsA total of 121 patients (mean age, 81.45 years) were colonized with VRE. The inpatient clearance rate was only 35.5%. The median time to VRE clearance during the hospital stay was 43 days. The independent predictors for VRE colonization during hospitalization were old-age-home residents [odds ratio (OR)=2.72; 95% confidence interval (CI), 1.14–6.48] and antibiotics use (OR=4.27; 95% CI, 1.89–9.62). Inpatient mortality was higher among those with persistent VRE colonization upon discharge (39.7% vs. 18.6%, p=0.017). Presence of wound or bed sores (OR=4.58; 95% CI, 1.16–13.2), chair/bed bound status (OR=3.64; 95% CI, 1.27–10.46), and persistent VRE colonization (OR=12.4; 95% CI, 3.16–42.52) were predictors for 1-year mortality. ConclusionThe strongest risk factor for prolonged VRE carriage was old-age-home residents. Survival is adversely affected by VRE carriage and functional mobility. Patients with these factors should be managed more carefully, and active surveillance should be focused on this high-risk group to prevent spread of transmission.

Molecular characterization of resistance, virulence and clonality in vancomycin-resistant Enterococcus faecium and Enterococcus faecalis: A hospital-based study in Beijing, China

The incidence of vancomycin-resistant enterococcus (VRE) in China is increasing, the molecular epidemiology of VRE in China is only partly known. This study was conducted to assess the molecular characterization of resistance, virulence and clonality of 69 vancomycin-resistant Enterococcus faecium (VREfm) and seven vancomycin-resistant Enterococcus faecalis (VREfs) isolates obtained from a Chinese hospital between July 2011 and July 2013. The glycopeptide resistance genes (VanA and VanB) were screened by multiplex PCR. The presence of five putative virulence genes (esp, gelE, asa1, hyl and cylA) were evaluated by another multiplex PCR. Multilocus sequence typing (MLST) scheme was used to assess the clonality. All 76 VRE isolates exhibited VanA phenotype and harbored VanA gene. Esp was the only gene detected both in VREfm and VREfs strains, accounting for 89.9% and 42.9%, respectively. The hyl gene was merely positive in 27.5% of VREfm strains. MLST analysis demonstrated three STs (ST6, ST4 and ST470) in VREfs and twelve STs (ST78, ST571, ST17, ST564, ST389, ST18, ST547, ST341, ST414, ST343, ST262 and ST203) in VREfm, which were all designated as CC17 by eBURST algorithm. An outbreak of VREfm belonging to ST571 was found to happen within the neurology ward in this hospital. To our knowledge, this is the first report of ST6 (CC2) VREfs strains in China and the first outbreak report of VREfm strains belonging to ST571 around the world. Our data could offer important information for understanding the molecular features of VRE in China.

Epidemiology of vancomycin-resistant enterococci in Canadian hospitals (CANWARD study, 2007 to 2013).

Of 1,927 Enterococcus species isolates collected across Canada from 2007 to 2013, 80 (4.2%) were identified as vancomycin-resistant enterococci (VRE). VRE infections during this time tripled in Canadian hospitals, from 1.8% to 6.0% (P = 0.03). All VRE were Enterococcus faecium, with 90% possessing vanA. The prevalence of vanB decreased from 37.5% in 2007 to 0% in 2013 (P < 0.05). The VRE were multidrug resistant, but 70.6%, 86.3%, and 100% were susceptible to doxycycline, linezolid, and daptomycin, respectively.

Dramatic increase in vancomycin-resistant enterococci in Germany

Among European countries, Germany has one of the highest proportions of vancomycin-resistant Enterococcus faecium bloodstream infections. The aim of this study was to investigate the development of vancomycin-resistant enterococci (VRE) in German hospitals and to consider the regional distribution of VRE in Germany. Data from three components of the German national nosocomial surveillance system (KISS) from the period 2007-12 were used for analysis: ICU-KISS data on nosocomial primary bloodstream infections and urinary tract infections from intensive care units (ICUs); OP-KISS data on surgical site infections from surgical departments; and Pathogen-KISS data concentrating on VRE cases (infections and colonizations) in ICUs. Trends over time were calculated and a map according to German federal states was prepared. Data from up to 645 ICUs and 681 surgical departments for 2 year periods from 2007 to 2012 were analysed. The proportion of VRE increased significantly for surgical site infections (526%; P < 0.01) and bloodstream infections (265%; P < 0.01) and non-significantly for urinary tract infections (278%; P = 0.07). A large subgroup of ICUs also reported VRE cases in the same period, with a significant increase of 282%. The mapping of federal states showed large variation in VRE proportions and incidence rates in a belt of states with significantly higher VRE proportions from west (North Rhine-Westphalia) to east (Saxony). The high overall VRE proportion in Germany is mainly due to the situation in four states. There is an urgent need to analyse the epidemiology of VRE in detail to develop appropriate infection control strategies.

Prevalence of vancomycin resistant Enterococci and associated risk factors among clients with and without HIV in Northwest Ethiopia: a cross-sectional study.

BackgroundEnterococci are the most important multidrug resistant organisms associated with immunocompromised patients. Data are lacking about the epidemiology of vancomycin resistant Enterococci (VRE) in Ethiopia. This study aimed to assess the prevalence of VRE, their susceptibility patterns to different antibiotics and associated risk factors in fecal samples of Human Immunodeficiency Virus (HIV) positive and HIV negative clients.MethodsA cross sectional study was carried out in a total of 226 (113 HIV positive and 113 HIV negative) clients, from July 1/2013 to September 30/2013 at the University of Gondar Teaching Hospital. Data on socio-demographic characteristics and risk factors were collected with a short interview guided by pre-tested structured questionnaire. The enterococci were isolated and identified from stool sample using standard bacteriological procedures. Kary Bauer disk diffusion method was used to determine the susceptibility patterns of Enterococci isolates. Data were entered and analyzed using SPSS version 20 statistical package.ResultsThe overall colonization of Enterococci was 88.9% (201/226) of which 11 (5.5%) were VRE. The prevalence of VRE among clients with and without HIV infections were 8(7.8%) and 3(3.1%), respectively. Ninety percent of the Enterococci isolates (181/201) were resistant to two or more antibiotics tested. Isolates of Enterococci recovered from stool samples of HIV infected patients were more resistant to amoxicillin and amoxicillin-calvulinic acid than HIV negative clients (P < 0.05). Antibiotic treatment for the last 2 weeks was found to be the risk factor that showed statistically significant association with the presence of high VRE colonization. However, the socio-demographic variables and factors such as malnutrition, leucopenia, thromobocytopenia, anaemia, duration of Highly Active Antiretroviral Therapy, CD4 cell count, stage of WHO and drinking alcohol were not associated with VRE (P > 0.05).ConclusionThe high prevalence of VRE in this study signals the emergence of VRE in the study area. Prior antibiotic treatment was associated with VRE colonization. Therefore, rational use of antibiotics and more detailed study using phenotypic and genotypic methods are needed.

A change in the molecular epidemiology of vancomycin resistant enterococci in Western Australia

A change in the molecular epidemiology of vancomycin resistant enterococci in Western Australia

P219 Diversity of vancomycin resistant Enterococcus in a low endemic area

The incidence of vancomycin-resistant enterococcus (VRE) in China is increasing, the molecular epidemiology of VRE in China is only partly known. This study was conducted to assess the molecular characterization of resistance, virulence and clonality of 69 vancomycin-resistant Enterococcus faecium (VREfm) and seven vancomycin-resistant Enterococcus faecalis (VREfs) isolates obtained from a Chinese hospital between July 2011 and July 2013. The glycopeptide resistance genes (VanA and VanB) were screened by multiplex PCR. The presence of five putative virulence genes (esp, gelE, asa1, hyl and cylA) were evaluated by another multiplex PCR. Multilocus sequence typing (MLST) scheme was used to assess the clonality. All 76 VRE isolates exhibited VanA phenotype and harbored VanA gene. Esp was the only gene detected both in VREfm and VREfs strains, accounting for 89.9% and 42.9%, respectively. The hyl gene was merely positive in 27.5% of VREfm strains. MLST analysis demonstrated three STs (ST6, ST4 and ST470) in VREfs and twelve STs (ST78, ST571, ST17, ST564, ST389, ST18, ST547, ST341, ST414, ST343, ST262 and ST203) in VREfm, which were all designated as CC17 by eBURST algorithm. An outbreak of VREfm belonging to ST571 was found to happen within the neurology ward in this hospital. To our knowledge, this is the first report of ST6 (CC2) VREfs strains in China and the first outbreak report of VREfm strains belonging to ST571 around the world. Our data could offer important information for understanding the molecular features of VRE in China.

Identification of vancomycin-resistant enterococci clones and inter-hospital spread during an outbreak in Taiwan.

BackgroundIn 2003, nosocomial infections caused by vancomycin-resistant enterococci (VRE) occurred rarely in Taiwan. Between 2003 and 2010, however, the average prevalence of vancomycin resistance among enterococci spp. increased from 2% to 16% in community hospitals and from 3% to 21% in medical centers of Taiwan. We used molecular methods to investigate the epidemiology of VRE in a tertiary teaching hospital in Taiwan.MethodsBetween February 2009 and February 2011, rectal samples and infection site specimens were collected from all inpatients in the nephrology ward after patient consent was obtained. VRE strain types were determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).ResultsA total of 59 vanA gene-containing VRE isolates (1 per patient) were obtained; 24 originated from rectal sample surveillance of patients who exhibited no symptoms (22 Enterococcus faecium and 2 Enterococcus faecalis), and 35 had developed infections over 3 days after admission (32 E. faecium, 2 E. faecalis, and 1 Enterococcus durans). The 59 VRE isolates demonstrated vancomycin minimum inhibitory concentrations (MICs) of ≥256 μg/m. The MIC range for linezolid, tigecycline, and daptomycin was 0.25–1.5 μg/mL, 0.032–0.25 and 1–4 μg/mL, respectively. For 56 isolates, the MIC for teicoplanin was >8 μg/mL. The predominant types in the nephrology ward were MLST types 414, 78, and18 as well as PFGE types A, C, and D.ConclusionVREs are endemic in nephrology wards. MLST 414 is the most predominant strain. The increase VRE prevalence is due to cross-transmission of VRE clones ST 414,78,18 by undetected VRE carriers. Because similar VRE STs had been reported in a different hospital of Taiwan, this finding may indicate inter-hospital VRE spread in Taiwan. Active surveillance and effective infection control policies are important controlling the spread of VRE in high risk hospital zones. All endemic VRE strains are resistant to teicoplanin but are sensitive to daptomycin, linezolid, and tigecycline.

Molecular epidemiology of vancomycin-resistant enterococcal bacteraemia: results from the Canadian Nosocomial Infection Surveillance Program, 1999-2009

Vancomycin-resistant enterococci (VRE) can be associated with serious bacteraemia. The focus of this study was to characterize the molecular epidemiology of VRE from bacteraemia cases that were isolated from 1999 to 2009 as part of Canadian Nosocomial Infection Surveillance Program (CNISP) surveillance activities. From 1999 to 2009, enterococci were collected from across Canada in accordance with the CNISP VRE surveillance protocol. MICs were determined using broth microdilution. PCR was used to identify vanA, B, C, D, E, G and L genes. Genetic relatedness was examined using multilocus sequence typing (MLST). A total of 128 cases of bacteraemia were reported to CNISP from 1999 to 2009. In 2007, a significant increase in bacteraemia rates was observed in western and central Canada. Eighty-one of the 128 bacteraemia isolates were received for further characterization and were identified as Enterococcus faecium. The majority of isolates were from western Canada (60.5%), followed by central (37.0%) and eastern (2.5%) Canada. Susceptibilities were as follows: daptomycin, linezolid, tigecycline and chloramphenicol, 100%; quinupristin/dalfopristin, 96.3%; high-level gentamicin, 71.6%; tetracycline, 50.6%; high-level streptomycin, 44.4%; rifampicin, 21.0%; nitrofurantoin, 11.1%; clindamycin, 8.6%; ciprofloxacin, levofloxacin and moxifloxacin, 1.2%; and ampicillin, 0.0%. vanA contributed to vancomycin resistance in 90.1% of isolates and vanB in 9.9%. A total of 17 sequence types (STs) were observed. Beginning in 2006 there was a shift in ST from ST16, ST17, ST154 and ST80 to ST18, ST412, ST203 and ST584. The increase in bacteraemia observed since 2007 in western and central Canada appears to coincide with the shift of MLST STs. All VRE isolates remained susceptible to daptomycin, linezolid, chloramphenicol and tigecycline.

Risk Factors Associated with Vancomycin-ResistantEnterococcusin Intensive Care Unit Settings in Saudi Arabia

Background. Vancomycin-resistant enterococci (VRE) are significant nosocomial pathogens worldwide. There is one report about the epidemiology of VRE in Saudi Arabia. Objective. To determine the risk factors associated with VRE infection or colonization in intensive care unit (ICU) settings. Design. This is a descriptive, epidemiologic hospital-based case-control study of patients with VRE from February 2006 to March 2010 in ICU in a tertiary hospital in Saudi Arabia. Methods. Data were collected from hospital records of patients with VRE. The main outcome measure was the adjusted odds ratio estimates of potential risk factors for VRE. Results. Factors associated with VRE included ICU admission for multiorgan failure, chronic renal failure, prior use of antimicrobial agents in the past three months and before ICU admission, gastrointestinal oral contrast procedure, and hemodialysis. Being located in a high risk room (roommate of patients colonized or infected with VRE) was found to be protective. Conclusions. Factors associated with VRE acquisition are often complex and may be confounded by local variables.

Epidemiology of Vancomycin-Resistant Enterococci with Reduced Susceptibility to Daptomycin

A retrospective case-case control study was conducted, including 60 cases with daptomycin-nonsusceptible vancomycin-resistant enterococci (DNS-VRE) matched to cases with daptomycin-susceptible VRE and to uninfected controls (1∶1∶3 ratio). Immunosuppression, presence of comorbid conditions, and prior exposure to antimicrobials were independent predictors of DNS-VRE, although prior daptomycin exposure occurred rarely. In summary, a case-case control study identified independent risk factors for the isolation of DNS-VRE: immunosuppression, multiple comorbid conditions, and prior exposures to cephalosporines and metronidazole.

Vancomycin-resistant Enterococci in Singaporean Hospitals: 5-year results of a Multi-centre Surveillance Programme

Vancomycin-resistant enterococci (VRE) have emerged as one of the major nosocomial antimicrobial-resistant pathogens globally. In this article, we describe the epidemiology of VRE in Singaporean public hospitals in the 5 years following the major local VRE outbreak in 2005. A passive laboratory surveillance programme identified non-duplicate VRE isolates from 7 hospitals from 2006 to 2010. Descriptive statistics and time-series analysis was performed on all clinical VRE isolates for each individual hospital as well as for the combined dataset. There were a total of 418 VRE isolates over 5 years, of which 102 isolates (24.4%) were from clinical cultures. Between 0.4% and 0.7% of all clinical enterococcal isolates were resistant to vancomycin. The overall incidence-density of VRE did not change over time in Singapore despite 2 separate outbreaks in tertiary hospitals in 2009 and 2010. Incidence-density of clinical VRE cases fell in 2 secondary hospitals, while another 2 hospitals experienced no significant VRE infections after 2008. The prevalence of VRE clinical isolates remains low in Singaporean public sector hospitals. However, the presence of at least 2 outbreaks in separate hospitals over the past 5 years indicates the need for continued vigilance in order to prevent any further increase in VRE prevalence locally.

Epidemiology of vancomycin-resistant enterococci in children with acute lymphoblastic leukemia at two referral centers in Tehran, Iran: a descriptive study

Risk factors for colonization with vancomycin-resistant enterococci (VRE) vary by population and locale. The objective of this study was to determine the prevalence of and risk factors for VRE colonization in children with acute lymphoblastic leukemia (ALL) in Tehran. Stools were collected from children with ALL at the Ali Asghar Children's Hospital and the Mahak Pediatric Oncology Center between March 2007 and October 2008. Demographic features and potential risk factors for VRE colonization, including duration of ALL, presence of severe neutropenia in the preceding month, receipt of antibiotics in the preceding 3 months, concurrent medical problems, days of hospitalization, and the need for intensive care since the time of diagnosis of ALL, were recorded. VRE was identified from stools in 33 of 130 children with ALL (25%). No clear risk factors were identified for VRE colonization in the current study, but there was a trend towards an increased prevalence in children admitted to the intensive care unit since their ALL diagnosis (p=0.07). The VanA genotype was found in 28 of the 33 stools (85%), with all other enterococci being VanB. The prevalence of VRE colonization in children with ALL in Tehran is high. Modifiable risk factors have not been identified. The implementation of routine surveillance for colonization and an increased emphasis on adherence to standard infection control precautions may prevent spread.

Epidemiology of Vancomycin Resistant Enterococcus (VRE) in a Singapore Tertiary Hospital

Epidemiology of Vancomycin Resistant Enterococcus (VRE) in a Singapore Tertiary Hospital

Epidemiology of Vancomycin-Resistant Enterococci Among Patients on an Adult Stem Cell Transplant Unit: Observations From an Active Surveillance Program

To use the findings of an active surveillance program to delineate the unique epidemiology of vancomycin-resistant enterococci (VRE) in a mixed population of transplant and nontransplant patients hospitalized on a single patient care unit. Surveillance survey and case-control analysis. A 19-bed adult bone marrow and stem cell transplant unit at a referral and primary-care center. The study included patients undergoing transplantation, patients who had previously received bone marrow or stem cell transplants, and patients with other malignancies and hematological disorders who were admitted to the study unit. Patients not previously identified as colonized with VRE had perirectal swab specimens collected at admission and once weekly while hospitalized on the unit. The prevalence of VRE colonization at admission and the incidence throughout the hospital stay, genotypes of VRE specimens as determined by pulsed field gel electrophoresis, and risk factors related to colonization were analyzed. There was no significant difference in the prevalence or incidence of new colonization between nontransplant patients and prior or current transplant recipients, although overall prevalence at admission was significantly higher in the prior transplant group. Preliminary genotypic analysis of VRE isolates from transplant patients suggests that a proportion of cases of newly detected VRE carriage may represent prior colonization not detected at admission, with different risk factors suggestive of a potential epidemiological distinction. Examination of epidemiological and microbiological data collected by an active surveillance program provides useful information about the epidemiology of VRE that can be applied to inform rational infection control strategies.