Risk factors and outcome on patients with vancomycin-resistant Enterococcus bllodstream infection at a university-affiliated hospital in São Paulo

0 enterococo resistente à vancomicina( VRE) é hoje patógeno de imensa importância no ambiente hospitalar, com aumento progressivo em sua incidência como causador de infecções nosocomiais. A bacteremia é uma das principais infecções causadas por este 1 patógeno e devido a sua importância e limitados dados nacionais foi definida como objeto deste estudo. Foram realizados dois estudos procurando avaliar a epidemiologia desta infecção em um hospital universitário . 0 primeiro estudo teve como objetivo avaliar os fatores de risco para bacteremia por VRE. No período de janeiro de 2001 a dezembro de 2003 foram estudados 34 pacientes com bacteremia por VRE, que foram comparados com 102 pacientes-controle pareados por ~ unidade de internação, sexo e idade. Tivemos durante o estudo uma incidência média de infecção de corrente sangüínea por VRE de 0,18 por 1000 pacientes-dia e de 0,11 por 100 saídas. A análise dos resultados demonstrou os seguintes fatores de risco estatisticamente significantes na análise univariada : uso de carbapenem( p= 0,003), uso de cefalosporinas p=0,017), uso de macrolídeos ( p= 0,025) , uso de polimixina B( p= 0,004), uso de vancomicina( p< 0,001), uso de cateter venoso central ( p= 0,023) , uso de ventilação mecânica( p= 0,021) , uso de sonda nasogástrica/nasoenteral( p= 0,001), tempo de internação( p< 0,001) e número de antibióticos(p= 0,001). Na análise multivariada, o único fator de risco independentemente associado à bacteremia por VRE foi : o uso prévio de vancomicina( OR= 10,19; IC9so¿= 3,63- 28,57)¿(au)Vancomycin-resistant Enterococcus( VRE) is currently a very important pathogen at hospital environment, with progressive increase on its incidence as a cause of nosocomial infections. Bacteremia is a leading infection caused by this pathogen and due its importance and restricted national data was defined as objective of this study. Two studies were performed in order to evaluate the epidemiology of this type of infection at an university-affiliated hospital. The first study evaluated the risk factors for bacteremia by VRE. During the period from january 2001 to december 2003 we studied 34 patients with bacteremia by VRE who were compared to 102 control-patients matched by admission unit, sex and age. We had a average incidence of bloodstream infection by VRE of 0.18 per 1000 patient-days and 0.11 per 100 discharges. The analysis of the results, showed that the following risk factors were statistically significant in univariate analysis: carbapenem use( p= 0,003), cephalosporin use( p= 0,017), macrolides use( p=0,025), polimyxyn use(p= 0,004), vancomycin use( p < 0,001), central venous catheter use( p= 0,023), mechanic ventilation use( p=0,021), nasogastric/nasoenteral tube use( p=0,001), lenght of hospital stay( p< 0,001) and number of antibiotics( p= 0,001). The only factor independently associated to bacteremia on multivariate analysis was : previous vancomycin use( OR= 10,19 ; IC95%= 3,63- 28,57). 113 The second study was performed with the aim to study comparatively the patients with bacteremia by VRE and VSE in order to define differences between the groups concerning clinical outcome. We studied 34 patients with VRE bacteremia and 55 patients with VSE bacteremia admitted in several hospital units. The analysis of results showed that the following factors were statistically significant on univariate analysis: previous carbapenem use( p= 0,001), previous vancomycin use( p< 0,001), mechanical ventilation( p=0,016), nasogastric/nasoenteral tube use( p= 0,004), vasoactive drug use( p= 0,013), lenght of hospital stay( p< 0,001), number of antibiotics( p= 0,001). The only factors statistically significants on multivariate analysis between the two groups were: vasoactive drug use ( OR= 3,61; CI95%= 1,02- 12,72) and number of antibiotics( OR= 1,57; CI95%= 1,15-2,15) in first model and vasoactive drug use( OR= 5,68; CI95%= 1,25- 25,89) and previous vancomycin use( OR= 17,58; CI95%= 5,24-58,96) in second model. The most common Enterococcus species that caused bloodstream infection in our study was E.faecalis( 100% in VRE group and 95,6% in VSE group). There was 100% of sensivity to ampicillin, streptomycin and linezolide in VRE group. Due the importance of VRE bacteremia in hospitals, it is crucial to define the main risk factors associated to it and to observe whether there is differences on outcome in enterococcal bacteremia concerning vancomycin resistance.BV UNIFESP: Teses e dissertaçõe

Predictors of 14-day mortality in patients with bloodstream infections caused by Enterobacteriaceae strains: a mathematical PK/PD analysis

Universidade Federal de São Paulo (UNIFESP) Hospital São Paulo Division of Infectious DiseasesUNIFESP, Hospital São Paulo Division of Infectious DiseasesSciEL

Impact of the introduction of an automated microbiologic system on the clinical outcomes of bloodstream infections caused by Enterobacteriaceae strains

INTRODUCTION: Enterobacteriaceae strains are a leading cause of bloodstream infections (BSI). The aim of this study is to assess differences in clinical outcomes of patients with BSI caused by Enterobacteriaceae strains before and after introduction of an automated microbiologic system by the microbiology laboratory. METHODS: We conducted a retrospective cohort study aimed to evaluate the impact of the introduction of an automated microbiologic system (Phoenix(tm) automated microbiology system, Becton, Dickinson and Company (BD) - Diagnostic Systems, Sparks, MD, USA) on the outcomes of BSIs caused by Enterobacteriaceae strains. The study was undertaken at Hospital São Paulo, a 750-bed teaching hospital in São Paulo, Brazil. Patients with BSI caused by Enterobacteriaceae strains before the introduction of the automated system were compared with patients with BSI caused by the same pathogens after the introduction of the automated system with regard to treatment adequacy, clinical cure/improvement and 14- and 28-day mortality rates. RESULTS: We evaluated 90 and 106 patients in the non-automated and automated testing periods, respectively. The most prevalent species in both periods were Klebsiella spp. and Proteus spp. Clinical cure/improvement occurred in 70% and 67.9% in non-automated and automated period, respectively (p=0.75). 14-day mortality rates were 22.2% and 30% (p=0.94) and 28-day mortality rates were 24.5% and 40.5% (p= 0.12). There were no significant differences between the two testing periods with regard to treatment adequacy, clinical cure/improvement and 14- and 28-day mortality rates. CONCLUSIONS: Introduction of the BD Phoenix(tm) automated microbiology system did not impact the clinical outcomes of BSIs caused by Enterobacteriaceae strains in our setting.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Hospital São PauloUNIFESP, EPM, Hospital São PauloSciEL

Prevalência e evolução clínica de episódios de pneumonia associada à ventilação mecânica causada por Pseudomonas aeruginosa resistente a imipenem produtoras e não-produtoras de SPM-1

INTRODUCTION: Pseudomonas aeruginosa is a leading cause of ventilator-associated pneumonia (VAP) and exhibits high rates of resistance to several antimicrobial drugs. The carbapenens are usually the drugs of choice against this microorganism. However, the carbapenem resistance has increased among these strains worldwide. The presence of metallo-β-lactamases (MBL) has been pointed out as a major mechanism of resistance among these strains. No previous study addressed outcomes of respiratory infections caused by these strains. METHODS: Our group sought to analyze the epidemiology and clinical outcomes of patients with VAP caused by imipenem-resistant P. aeruginosa. A total of 29 clinical isolates of carbapenem-resistant Pseudomonas aeruginosa were screened for metallo-β-lactamase (MBL) genes. RESULTS: Demographic and clinical variables were similar between the SPM-1-producing and non-SPM-1-producing group. Five (17.2%) isolates were positive for blaSPM-1. No other MBL gene was found. All patients were treated with polymyxin B. The infection-related mortality was 40% and 54.2% for SPM-1-producing and -non-producing isolates, respectively. CONCLUSIONS: There were no differences in epidemiological and clinical outcomes between the two groups.INTRODUÇÃO: Pseudomonas aeruginosa é uma importante causa de pneumonia associada à ventilação mecânica (PAV) e exibe altas taxas de resistência a vários antimicrobianos. Os carbapenens são usualmente as drogas de escolha para esse microorganismo. Contudo, a resistência a carbapenens tem crescido entre essas amostras em todo o mundo. A presença de metalo- β-lactamase (MBL) tem sido apontado como um importante mecanismo de resistência nessas cepas. Nenhum estudo prévio avaliou desfechos clínicos de infecções respiratórias causadas por essas amostras MÉTODOS: Nosso grupo analisou a epidemiologia e evolução clínica de episódios de PAV causada por P. aeruginosa resistente a imipenem. Um total de vinte e nove isolados clínicos de Pseudomonas aeruginosa resistente a carbapenem foram avaliados quanto à presença de genes para metalo-β-lactamase (MBL). RESULTADOS: Variáveis clínicas e demográficas foram similares entre o grupo produtor de SPM-1 e o não-produtor. Cinco (17,2%) isolados foram positivos para blaSPM-1. Nenhum outro gene para MBL foi encontrado. Todos os pacientes foram tratados com polimixina B. A mortalidade relacionada à infecção foi de 40% e 50% respectivamente para os isolados produtores de SPM-1 e não-produtores de SPM-1. CONCLUSÕES: Nao houve diferença entre os dados epidemiológicos e a evolução clínica entre os dois grupos.Universidade Federal de São Paulo (UNIFESP) Divisão de Doenças Infecciosas Comissão de Epidemiologia HospitalarUniversidade Federal de São Paulo (UNIFESP) Divisão de Doenças Infecciosas Laboratório de AlertaUNIFESP, Divisão de Doenças Infecciosas Comissão de Epidemiologia HospitalarUNIFESP, Divisão de Doenças Infecciosas Laboratório de AlertaSciEL

Prevalence and factors associated with rectal vancomycin-resistant enterococci colonization in two intensive care units in São Paulo, Brazil

Vancomycin-resistant enterococci (VRE) are important pathogens causing nosocomial infections, and there is reason for concern about their resistance and great ability to spread in hospital environments, especially intensive-care units (ICU). To determine the prevalence of rectal colonization by VRE, and the risk factors associated with their presence, rectal surveillance swabs were taken from patients under treatment in two intensive-care units (one medical and another both medical and surgical) at São Paulo Hospital, over a two-year period. Thirty-three percent of the 147 patients evaluated had VRE. The only significant variable in the logistic regression was the length of stay in the ICU.Federal University of São Paulo Hospital Epidemiology Committee Division of Infectious DiseasesUNIFESP, Hospital Epidemiology Committee Division of Infectious DiseasesSciEL

Rapid detection of Vancomycin-Resistant Enterococci (VRE) in rectal samples from patients admitted to intensive care units

ABSTRACT: The reduction in time required to identify vancomycin-resistant enterococci (VRE) has gained increased importance during hospital outbreaks. In the present study, we implemented a laboratory protocol to speed up the VRE screening from rectal samples. The protocol combines a medium for selective VRE isolation (VREBAC®, Probac, São Paulo) and a multiplex PCR for detection and identification of vanA and vanB resistance genes. The screening performance was analyzed in 114 specimens collected from four intensive care units. The swabs were collected at two periods: (1) during a VRE outbreak (February 2006, n=83 patients) and (2) at the post-outbreak period, after adoption of infection control measures (June 2006, n=31 patients). Forty-one/83 VRE (49.4%) and 3/31(9.7%) VRE were found at the first and second period, respectively. All isolates harbored the vanA gene. In both periods, detection of the gene vanA parallels to the minimum inhibitory concentration values of >256 µg/mL and >48 µg/mL for vancomycin and teicoplanin, respectively. Multiplex PCR and conventional methods agreed in 90.2% for enterococci identification. Besides this accuracy, we also found a remarkable reduction in time to obtain results. Detection of enterococcal species and identification of vancomycin resistance genes were ready in 29.5 hours, in comparison to 72 hours needed by the conventional methods. In conclusion, our protocol identified properly and rapidly enterococci species and vancomycin-resistance genes. The results strongly encourage its adoption by microbiology laboratories for VRE screenning in rectal samples

Incidence of vancomycin-resistant Enterococcus at a university hospital in Brazil

OBJECTIVE: Vancomycin-resistant Enterococcus (VRE) is today one of the principal microorganisms implicated in nosocomial infections. Thus, a study was carried out with the objective of evaluating its epidemiology at a tertiary-level teaching hospital. METHODS: This was a three-year retrospective epidemiological study conducted from 2000 to 2002. Samples of VRE-positive clinical cultures at a 660-bed university hospital were analyzed. The incidence of VRE and the main anatomical sites and hospital units from which it was isolated were defined. Differences between the variables over the three years of the study were verified, and these were considered significant when p<0.05. RESULTS: There was a progressive increase in the vancomycin resistance in the clinical cultures that were positive for Enterococcus spp., over the three years of the study. In 2000, 9.5% of the samples were vancomycin-resistant, and this increased to 14.7% in 2001 and 15.8% in 2002. The hospital units with the largest numbers of isolates were, respectively, the emergency ward (19.5%) and the general intensive care unit (15%). The anatomical sites with the highest amounts of isolates included: urine (36%) and blood (20%). CONCLUSIONS: With the progressive increase in the incidence of vancomycin resistance and the VRE rate, it is concluded that more effective control measures are needed for deterring the dissemination of VRE.OBJETIVO: O enterococo resistente à vancomicina é atualmente um dos principais microorganismos implicados em infecções nosocomiais. Assim, realizou-se estudo com o objetivo de avaliar sua epidemiologia em um hospital terciário de ensino. MÉTODOS: Trata-se de um estudo epidemiológico retrospectivo, realizado de 2000 a 2002, que analisou amostras de culturas clínicas positivas para enterococo resistente à vancomicina (VRE) em um hospital universitário com 660 leitos. Procurou-se definir sua incidência e os principais sítios e unidades de isolamento. Foi verificada a significância entre as variáveis nos três anos de estudo, sendo considerado como significante p<0,05. RESULTADOS: Houve aumento progressivo na resistência à vancomicina nas culturas clínicas positivas para Enterococcus spp. nos três anos de estudo. Em 2000, 9,5% das amostras eram resistentes à vancomicina, com aumento para 14,7% em 2001 e 15,8% em 2002. As unidades com maior número de isolados foram respectivamente: pronto-socorro (19,5%) e UTI geral (15%); os sítios mais isolados foram: urina (36%) e sangue (20%). CONCLUSÕES: Com o aumento progressivo na incidência de resistência à vancomicina e da taxa de VRE, concluiu-se ser necessárias medidas de controle mais efetivas para deter a disseminação do VRE.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Disciplina de Doenças Infecciosas e ParasitáriasUNIFESP, EPM, Disciplina de Doenças Infecciosas e ParasitáriasSciEL

Application of control measures for infections caused by multi-resistant gram-negative bacteria in intensive care unit patients

Multi-resistant gram-negative rods are important pathogens in intensive care units (ICU), cause high rates of mortality, and need infection control measures to avoid spread to another patients. This study was undertaken prospectively with all of the patients hospitalized at ICU, Anesthesiology of the Hospital São Paulo, using the ICU component of the National Nosocomial Infection Surveillance System (NNIS) methodology, between March 1, 1997 and June 30, 1998. Hospital infections occurring during the first three months after the establishment of prevention and control measures (3/1/97 to 5/31/97) were compared to those of the last three months (3/1/98 to 5/31/98). In this period, 933 NNIS patients were studied, with 139 during the first period and 211 in the second period. The overall rates of infection by multi-resistant microorganisms in the first and second periods were, respectively, urinary tract infection: 3.28/1000 patients/day; 2.5/1000 patients/day; pneumonia: 2.10/1000 patients/day; 5.0/1000 patients/day; bloodstream infection: 1.09/1000 patients/day; 2.5/1000 patients/day. A comparison between overall infection rates of both periods (Wilcoxon test) showed no statistical significance (p = 0.067). The use of intervention measures effectively decreased the hospital bloodstream infection rate (p < 0.001), which shows that control measures in ICU can contribute to preventing hospital infections.Universidade Federal de São Paulo (UNIFESP) Departamento de Medicina Comissão de Epidemiologia HospitalarUNIFESP, Depto. de Medicina Comissão de Epidemiologia HospitalarSciEL