Outpatient vancomycin use and vancomycin-resistant enterococcal colonization in maintenance dialysis patients

The Role of the Environment and Colonization in Healthcare-Associated Infections

Healthcare-associated infections (HAIs) can be caused by endogenous host microbial flora or by exogenous microbes, including those found in the hospital environment. Efforts to decrease endogenous pathogens via decolonization and skin antisepsis may decrease the risk of infection in some settings. Controlling the spread of potential pathogens from the environment requires meticulous attention to cleaning and disinfection practices. In addition to selection of the appropriate cleaning agent, use of tools that assess the adequacy of cleaning and addition of no-touch cleaning technology may decrease environmental contamination. Hand hygiene is also a critical component of preventing transmission of pathogens from the environment to patients via healthcare worker hands.

Prevalence of vancomycin resistance among isolates of enterococci in Iran: a systematic review and meta-analysis

Introduction

Enterococcus is responsible for 10% of hospital-acquired infections. The purpose of this review was to evaluate the prevalence of vancomycin-resistant Enterococcus (VRE) isolates in Iran using a meta-analysis method.

Materials and methods

Iranian databases, including Magiran and IranDoc, and international databases, including PubMed and MedLib, were examined carefully, and a total of 20 articles published between 2000 and 2011 were extracted. The data were subjected to meta-analysis and random-effects models. In addition, heterogeneous studies were assessed using the I ² index. Finally, the data were analyzed using R and STATA software.

Results

The results showed that the strain of Enterococcus faecalis had been more common than Enterococcus faecium in clinical infection (69% vs 28%). However, resistance to vancomycin was higher among strains of E. faecium compared with strains of E. faecalis (33% vs 3%). The complete resistance, intermediate resistance, and sensitivity to vancomycin among Enterococcus isolates were 14% (95% CI: 11, 18), 14% (95% CI: 5, 23), and 74% (95% CI: 65, 83), respectively. The resistance patterns, depending on the sample type, did not show a significant difference. In addition, the resistance of isolated strains to vancomycin in outpatients was significantly higher than that in inpatients (16% vs 1%). Moreover, 80%-86% of resistant strains were genotype van A and 14%-20% of resistant strains were genotype van B.

Conclusion

The findings of the present review show that there is a high frequency of resistant Enterococcus in Iran. Therefore, consideration of the prevalence and frequency of subjected resistant strains can be helpful for decision makers to implement proper health policies in this direction.

Risk Factors and Outcomes of Vancomycin-Resistant Enterococcus Colonization in Patients on Peritoneal Dialysis: A Single-Center Study in Hong Kong

BACKGROUND

Vancomycin-resistant Enterococcus (VRE) colonization is common among patients with chronic kidney disease. However, data concerning VRE colonization among patients receiving peritoneal dialysis (PD) is lacking. The aim of this study is to evaluate the risk factors and various clinical outcomes for VRE colonization among PD patients.

METHODS

This is a retrospective cohort study of 166 PD patients who were hospitalized between 1 August 2013 and 31 July 2014. They were screened for VRE colonization status during a major VRE outbreak in Hong Kong in 2013 and were then categorized into 2 groups: VRE-positive and VRE-negative. The primary outcome was all-cause mortality while the secondary outcomes included VRE infection, PD-related peritonitis, and length of hospitalization.

RESULTS

Twenty-eight patients (16.9%) belonged to the VRE-positive group. Multivariate analysis showed that previous contact with VRE-positive patients (odds ratio [OR]: 417.86; 95% confidence interval [CI]: 17.21 - 10,147.26, p < 0.01), vancomycin use in previous 3 months (OR: 130.32; 95% CI: 5.35 - 3,176.30, p < 0.01), and old age (OR: 1.13; 95% CI: 1.02 - 1.24, p = 0.02) were the independent risk factors for VRE colonization. Patients in the VRE-positive group had significantly longer length of hospitalization, but there was no significant difference in all-cause mortality and peritonitis-free survival.

CONCLUSION

Vancomycin-resistant Enterococcus colonization is important among hospitalized PD patients. Cautious use of antibiotics and infection control measures are necessary to prevent VRE spreading, especially in high-risk patients.

Vancomycin-resistant enterococci colonization among dialysis patients: a meta-analysis of prevalence, risk factors, and significance

BACKGROUND

Vancomycin-resistant enterococci (VRE) have become important nosocomial pathogens causing outbreaks worldwide. Patients undergoing dialysis represent a vulnerable population due to their comorbid conditions, frequent use of antibacterial agents, and frequent contact with health care settings.

STUDY DESIGN

Systematic review and meta-analysis of cross-sectional studies of screening for VRE colonization.

SETTING & POPULATION

Patients receiving long-term dialysis treatment.

SELECTION CRITERIA FOR STUDIES

We performed a systematic literature search of PubMed and EMBASE databases to identify studies performing screening for VRE colonization among dialysis patients.

PREDICTOR

Region, recent use of vancomycin or other antibiotics, previous hospitalization.

OUTCOMES

(1) VRE colonization and (2) rate of VRE infection among colonized and noncolonized individuals. Relative effects were expressed as ORs and 95% CIs.

RESULTS

We identified 23 studies that fulfilled the inclusion criteria and provided data for 4,842 dialysis patients from 100 dialysis centers. The pooled prevalence of VRE colonization was 6.2% (95% CI, 2.8%-10.8%), with significant variability between centers. The corresponding number for North American centers was 5.2% (95% CI, 2.8%-8.2%). Recent use of any antibiotic (OR, 3.62; 95% CI, 1.22-10.75), particularly vancomycin (OR, 5.15; 95% CI, 1.56-17.02), but also use of antibiotics other than vancomycin (OR, 2.92; 95% CI, 0.99-8.55) and recent hospitalization (OR, 4.55; 95% CI, 1.93-10.74) significantly increased the possibility of a VRE-positive surveillance culture. Colonized patients had a significantly higher risk of VRE infection (OR, 21.62; 95% CI, 5.33-87.69) than their noncolonized counterparts.

LIMITATIONS

In 19 of 23 studies, a low percentage of dialysis patients (<80%) consented to participate in the screening procedure. 4 of 8 studies in which patients were followed up for more than 1 month reported VRE infections and only 5 of 23 studies provided extractable data for antibiotic consumption prior to screening.

CONCLUSIONS

VRE colonization is prevalent in dialysis centers. Previous antibiotic use, in particular vancomycin, and recent hospitalization are important predicting factors of colonization, whereas the risk of VRE infection is significantly higher for colonized patients.

Multidrug-resistant organisms in dialysis patients

Multidrug-resistant organisms (MDROs) have emerged as important causes of healthcare-associated infections (HAIs), and these infections are associated with significant morbidity and mortality. Dialysis patients have been particularly affected by these pathogens, with colonization and infection rates often exceeding those seen in persons with other types of healthcare exposure. The infection control practices that are currently recommended for use in dialysis facilities and other healthcare settings have the potential to eliminate, or at least substantially reduce transmission of and infection with MDROs. Unfortunately, recent data suggest that these recommended practices are not consistently implemented. Additional efforts and research are needed to increase healthcare workers' awareness of and adherence to infection prevention measures, to develop new and more effective prevention strategies, and to determine cost-effective approaches to MDRO prevention to optimize the safety and quality of care provided to dialysis patients.

Successful prevention of tunneled central catheter infection by antibiotic lock therapy using cefazolin and gentamicin

Catheter-related bacteremia (CRB) is one of the various complications related to hemodialysis (HD). As a result of this high rate of infection, the antibiotic lock technique (ALT) has been recommended to prevent CRB. However, adverse effects of ALT such as increased emergence of strains resistant to antibiotics and increased mechanical dysfunction catheter were poorly evaluated. We prospectively evaluated the efficacy of catheter-restricted filling using an antibiotic lock solution in preventing CRB. A total of 233 HD patients requiring 325 new tunneled catheters while waiting for placement and maturation of an arteriovenous fistula or graft were enrolled in this study. Patients with a tunneled catheter were assigned to receive either an antibiotic-heparin lock solution (antibiotic group: cefazolin 10 mg/ml, gentamicin 5 mg/ml, heparin 1,000 U/ml) or a heparin lock solution (no-antibiotic group: heparin 1,000 U/ml) as a catheter lock solution during the interdialytic period. The present study aimed to assess the efficacy of ALT using cefazolin and gentamicin in reducing CRB in patients undergoing HD with tunneled central catheter and to identify its adverse effects. CRB developed in 32.4 % of patients in the no-antibiotic group and in 13.1 % of patients in the antibiotic group. CRB rates per 1,000 catheter-days were 0.57 in the antibiotic group versus 1.74 in the no-antibiotic group (p < 0.0001). Kaplan-Meier analysis also showed that mean CRB-free catheter survival was significantly higher in the antibiotic group than in the no-antibiotic group (log-rank statistic 17.62, p < 0.0001). There was statistically significant difference between the two groups in causative organisms of CRB, with predominance of negative culture in both groups, but this prevalence was higher in ALT group (57.9 vs 90.1 %, p < 0.0001), and the two groups also were different in prevalence of gram-positive bacteria as causing organisms (ALT group 21.05 vs = 0 % in control group, p < 0.0001). There was no statistically significant difference between the two groups in drug-resistant germs. There were statistically significant differences between the two groups in the catheter removal causes, with higher rate of infectious cause in control group (12.32 vs 2.22 %, p < 0.0001) and mechanical cause in ALT group (28.26 vs 37.78 %, p < 0.0001). The results suggest that ALT may be a beneficial means of reducing the CRB rate in HD patients with tunneled catheter, without association between ALT and emergence of strains resistant. However, mechanical complications were more prevalent in antibiotic group. Further studies are required to determine the optimal drug regimen, concentrations for ALT, and its adverse effects.

Novel antimicrobial-resistant bacteria among patients requiring chronic hemodialysis

PURPOSE OF REVIEW

Antimicrobial-resistant bacteria (ARB) including resistant strains of Staphylococcus aureus, enterococci, and Gram-negative bacteria have the potential to cause serious infections among patients requiring chronic hemodialysis (CHD). The purpose of this article is to review novel ARB, which have emerged in this patient population, their mechanisms of transmission, and preventive efforts aimed at limiting their dissemination.

RECENT FINDINGS

New strains of ARB, including community-acquired methicillin-resistant S. aureus, S. aureus strains with reduced susceptibility to vancomycin, vancomycin-resistant S. aureus and multidrug-resistant Gram-negative bacteria (MDRGN), are emerging among the CHD population. Extended-spectrum β-lactamase Gram-negative bacteria (ESBLGN) are among the most common MDRGN strains. These ESBLGN are resistant to the great majority of antimicrobials. The carbapenems remain the only optimal antimicrobial choice to treat ESBLGN infections. Intrafacility spread of ARB in dialysis units occurs between patients through contaminated hands and clothes of healthcare workers (HCWs), as well as contaminated inanimate surfaces. Spread of ARB to family members of both patients and HCWs has also been documented.

SUMMARY

Colonization and infection with ARB continues to present a significant threat to patients receiving CHD. Interventions to reduce the spread of ARB should include infection control measures and judicious use of antimicrobials.

Rectal culture screening for vancomycin-resistant enterococcus in chronic haemodialysis patients: false-negative rates and duration of colonisation

Infection or colonisation with vancomycin-resistant enterococci (VRE) is common in chronic haemodialysis (HD) patients. However, there is limited information on the duration of VRE colonisation or on the reliability of consecutive negative rectal cultures to determine the clearance of VRE in chronic HD patients. Chronic HD patients from whom VRE was isolated were examined retrospectively. Rectal cultures were collected more than three times, at least one week apart, between 1 June 2003 and 1 March 2010. The results of the sequential VRE cultures and patients' data were analysed. Among 812 patients from whom VRE was isolated, 89 were chronic HD patients and 92 had three consecutive negative cultures. It took 60.7 ± 183.9 and 111.4 ± 155.4 days to collect three consecutive negative cultures in the 83 non-chronic haemodialysis patients and nine chronic HD patients, respectively (P = 0.011). The independent risk factors for more than three negative sequential rectal cultures were glycopeptide usage [odds ratio (OR): 2.155; P = 0.003] and length of hospital stay (OR: 1.009; P = 0.001). After three consecutive negative rectal cultures, two of six chronic HD patients and 10 of 36 non-HD patients were culture positive again. In conclusion, a significant proportion of patients colonised with VRE cannot be detected by three-weekly rectal cultures, and the duration of VRE colonisation in chronic haemodialysis patients tends to be prolonged. These results may be contributing to the continued increase in the prevalence of VRE.

A Monte Carlo analysis of peritoneal antimicrobial pharmacokinetics

Peritoneal dialysis-associated peritonitis (PDAP) can be treated using very different regimens of antimicrobial administration, regimens that result in different pharmacokinetic outcomes and systemic exposure levels. Currently, there is no population-level pharmacokinetic framework germane to the treatment of PDAP. We coupled a differential-equation-based model of antimicrobial kinetics to a Monte Carlo simulation framework, and conducted "in silico" clinical trials to explore the anticipated effects of different antimicrobial dosing regimens on relevant pharmacokinetic parameters (AUC/MIC and time greater than 5 ×MIC) and the level of systemic exposure.

Vascular access-related infections: definitions, incidence rates, and risk factors

Hemodialysis is associated with a high risk of morbidity and mortality, often caused by infections. Infections account for approximately 15% of all deaths in this patient population (the second leading cause after cardiovascular events) and for about one-fifth of admissions. Approximately one-fourth of infection-related admissions are caused by dialysis-associated peritonitis or vascular access infection that may lead to such significant complications as endocarditis or death. Published studies that assessed the determinants of hemodialysis-related vascular infections reported inconsistent findings. Variations in the definitions of infection among these studies despite the existence of standard guidelines proposed by at least 3 major work groups may explain, at least in part, these inconsistencies. A comprehensive in-depth review of those studies is needed to examine the inconsistencies in the published results. We first revised the existing vascular access-related infection definitions, then conducted a narrative review of the published literature that examined predictors of vascular access-related infections, highlighting the heterogeneity in methods and findings. Better understanding of the risk factors for vascular access-related infections may inform efficacious prevention strategies and lead to early detection of infections and improved patient care.

Assessment of vancomycin use in chronic haemodialysis patients: room for improvement

BACKGROUND

Vancomycin is frequently prescribed for the management of infections in haemodialysis patients. We evaluated the appropriateness of vancomycin use in our chronic haemodialysis population.

METHODS

Charts of all chronic haemodialysis patients who received vancomycin between 1 March 2003 and 1 March 2004 were retrospectively reviewed. Indication was assessed according to the modified Hospital Infection Control Practices Advisory Committee guidelines for vancomycin prescription. The prescribed dosing regimens were evaluated.

RESULTS

A total of 163 courses of vancomycin in 105 patients were assessed. Of all courses, 88% were considered to be initially appropriate, but this decreased to 63% once culture and sensitivity results were available. Use of vancomycin for the management of beta-lactam-sensitive organisms accounted for the majority of inappropriate use. The most common vancomycin-dosing regimen prescribed was 500 mg intravenously at each haemodialysis session (51%); however, considerable variability was observed.

CONCLUSIONS

Although the initial indication for vancomycin use was generally appropriate, inappropriate continuation of this antibiotic, failure to obtain proper cultures to guide therapy and potentially subtherapeutic dosing regimens were some of the challenges identified. Centres providing chronic haemodialysis should take steps to optimize vancomycin prescription to improve clinical outcomes and reduce the risk of antimicrobial resistance.

Prevalence of vancomycin-resistant enterococci colonization and its risk factors in chronic hemodialysis patients in Shiraz, Iran

Background

Vancomycin-resistant entrococci (VRE) are increasing in prevalence at many institutions, and are often reported in dialysis patients. The aim of this cross-sectional prevalence study was to determine the prevalence and risk factors of VRE colonization in chronic hemodialysis patients in two hemodialysis centers in Shiraz, Iran.

Methods

Rectal swabs were obtained from all consenting patients and were streaked on the surface of Cephalexin-aztreonam-arabinose agar (CAA) and incubated at 37°C in air for 24 h. The vancomycin susceptibility of each isolate was confirmed by disk susceptibility testing. The MICs of vancomycin and teicoplanin were confirmed by the E test. To identify risk factors, a questionnaire was completed for all the studied patients and the data of VRE positive and negative groups were compared using Man-Withney U test for continues data and the Fisher exact test for categorical data.

Results

Of 146 patients investigated, 9 (6.2%) were positive for VRE. All VRE strains were genotypically distinguishable. Risk factors for a VRE-positive culture were "antimicrobial receipt within 2 months before culture" (P = 0.003) and "hospitalization during previous year" (P = 0.016).

Conclusion

VRE colonization is an under-recognized problem among chronic dialysis patients in Iran. VRE colonization is associated with antibiotic consumption and hospitalization.

The prevalence of resistant bacterial colonization in chronic hemodialysis patients

BACKGROUND

Hospitalized dialysis patients are at increased risk for colonization and infection with resistant bacterial strains.

METHODS

We performed a cross-sectional analysis of the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) colonization in 198 hemodialysis outpatients, 75 of whom had longitudinal screening data from prior hospitalization. Nasal specimens for MRSA, perirectal specimens for VRE, and permanent catheter exit site specimens were collected.

RESULTS

MRSA colonization was present in 5.6% and VRE colonization in 3.14%. Univariate analyses revealed that prior exposure (defined as infection/colonization) with MRSA, hospitalization, and low serum albumin were associated with MRSA colonization. VRE colonization was associated with hospitalization, prior VRE or MRSA exposure, low serum albumin, and low ferritin. Multivariate analyses revealed MRSA colonization was predicted by prior MRSA exposure and VRE colonization was predicted by prior VRE exposure and number of hospitalizations. Among the 75 participants with longitudinal screening data, MRSA colonization was associated with prior MRSA history, and VRE colonization was associated with prior MRSA or VRE.

CONCLUSIONS

Generally low rates of MRSA and VRE colonization were observed in hemodialysis outpatients. Prior hospital screening was predictive of future outpatient colonization and may be useful in risk assessment.

UNRESOLVED ISSUES IN DIALYSIS: Long-Term Management of the Tunneled Venous Catheter

Despite their propensity for significant complications, tunneled central venous catheters have become a common means of vascular access in the United States for patients requiring maintenance hemodialysis for end-stage renal disease (ESRD). Reasons for their use include advanced patient age, peripheral vascular disease (arterial and venous), late referral for creation of vascular access, and more importantly, the lack of an interdisciplinary service line on vascular access among vascular surgeons, radiologists, and nephrologists. This review article summarizes complications commonly encountered in dialysis patients who use tunneled central venous catheters for vascular access-mainly thrombosis, stenosis, and infection. Special attention is given to novel approaches for the prevention of catheter-associated infections. Effective prevention and timely treatment of common catheter-associated complications can reduce the substantial morbidity associated with the use of these devices. However, these measures should not detract from the goal of avoiding or limiting the long-term use of catheters, thereby optimizing vascular access management by ensuring the timely availability of functioning arteriovenous fistulas.

Burden of Infection in Patients with End-Stage Renal Disease Requiring Long-Term Dialysis

BACKGROUND

This study examines the spectrum of infections in a selected population of patients requiring long-term dialysis, enlarging the focus beyond infections associated with the dialysis process.

METHODS

Infection data were reviewed from complete archived inpatient and outpatient dialysis records of 433 patients who were treated at a single hospital-based dialysis program and its dialysis satellites over a 9-year period, from 1 January 1992 to 31 December 2000.

RESULTS

The study period included 424,700 days of dialysis experience. A total of 2412 episodes of bacterial or fungal infections were treated in 433 patients. The infection rate was 5.7 episodes per 1000 days of dialysis. Patients received 5111 courses of antibiotics over 42,627 days of treatment, which cumulatively accounted for 10% of the total days of the study. Infections associated with hemodialysis vascular access devices comprised 20.5% of the total episodes. Infections below the knee (19.3% of infection episodes), pneumonia (13%), and other skin and soft-tissue infections (9%) were also important types and sources of infection, accounting for >42% of the total episodes. Eighty-two percent of the infections (1971 episodes) were acquired in the community. Of these, 868 (44%) required hospitalization. An additional 441 episodes were nosocomial. The profile of bacteria isolated from patients with community-acquired infections mirrored that of bacteria recovered from patients with nosocomial infections.

CONCLUSION

Patients with end-stage renal disease have an enormous burden of infection. The majority of the infections are unrelated to dialysis. Frequent and long-term antibiotic use and cohorting of patients in the dialysis unit have altered the microbiological flora of such individuals, with clinical and epidemiological implications.

Dynamic Analysis of Peritoneal Dialysis Associated Peritonitis

Peritoneal dialysis associated peritonitis (PDAP) has a historical incidence of approximately 0.3 to 0.5 episodes per patient per year; it represents the leading cause for hospitalization in patients on peritoneal dialysis (PD) and imposes a significant burden of morbidity. PDAP is unique in that each dialysis exchange removes a relatively large fraction of the bacteria laden free intraperitoneal fluid. The attendant removal of bacteria existing in the fluid phase (planktonic bacteria) may interact with bacterial growth to modulate the rate at which the peritoneal burden of microorganisms is reduced. We investigated the potential interactions between bacterial growth dynamics, multiphase bacterial kinetics, and mechanical clearance of microorganisms using simple mathematical analyses based upon in vitro data regarding bacterial growth kinetics in peritoneal dialysate. There are strong dynamic interactions predicted between fluid phase bacterial kinetics, dialysis prescription, and the mechanical clearance of planktonic peritoneal bacteria. There are also strong interactions between fluid phase bacterial kinetics and the kinetics of biofilm/sanctuary site formation and clearance. More frequent exchanges might significantly hasten the clearance of intraperitoneal planktonic bacteria in the absence of catheter-associated bacterial biofilm. The formation of bacteria laden biofilm raises the possibility of a "commensal state," in which ongoing mechanical clearance limits the total peritoneal bacterial burden.

Dissemination of vancomycin-resistant enterococci among haemodialysis patients in Athens, Greece

OBJECTIVES

Vancomycin-resistant enterococci (VRE) may colonize haemodialysis patients, but their epidemiology in this population is not well defined. Within the few last years, VRE strains have emerged and are increasingly isolated in the nosocomial environment in Greece, but colonization of dialysis patients has never been evaluated before. This study sought to determine the epidemiology of VRE colonization within this high-risk population and define the risk factors.

MATERIALS AND METHODS

During a 4 month period, rectal swabs or faecal specimens were collected from 334 consecutive outpatients, who were treated at four independent dialysis units located in the same area of Athens and referring patients to the same local hospital. The relatedness of isolates was defined by molecular typing, and demographic and clinical patient data were recorded.

RESULTS

Thirteen multiresistant Enterococcus faecium vanA strains were isolated corresponding to a colonization frequency of 3.9%. They were separated into seven clusters: type A (two strains), type B (six strains) and types C to G (one strain each). Type B strains originated from three units, while a single unit demonstrated four type B and two type A strains. Univariate statistical analysis revealed that prior hospitalization (P=0.001), prior administration of antimicrobials (P=0.026) and male gender (P=0.019) were associated with VRE colonization.

CONCLUSIONS

In Greece, haemodialysis patients are colonized with VRE at a low frequency. The predominance of one clone and its isolation from several units strongly indicate interfacility transmission of strains, most probably within a health care environment shared by all patients.

Implications of colonization of vancomycin-resistant enterococci (VRE) in renal dialysis patients. Learning to live with it?

Vancomycin-resistant enterococci (VRE) commonly colonize, but less frequently infect, debilitated patients, such as those on chronic renal dialysis. The emergence of VRE amongst our cohort of renal replacement therapy patients posed considerable challenges in our attempts to prevent spread. Although 60 of 451 (13%) patients became colonized, only two patients required systemic antibiotics for confirmed or suspected invasive infection. Mortality and inpatient stay was greater in VRE-positive compared with VRE-negative patients (50% versus 10%) and patients who were screened on three or more occasions were likely to remain positive (e.g. 56% of patients screened on six occasions were positive). The application of recommended guidelines for the control of VRE, however, severely disrupted our renal dialysis programme and therefore had to be abandoned. As patients on renal dialysis are more likely to acquire VRE, remain colonized, require antibiotics and require regular inpatient or outpatient care more frequently than other patients, control measures should be adapted to minimize spread but not disrupt important and essential medical services.

Bacteremia and Infective Endocarditis in Patients on Hemodialysis

The number of patients with end-stage renal disease (ESRD) has risen dramatically over the last decade. There are 300,000 patients in the United States with ESRD who are receiving hemodialysis (HD), and the incidence is increasing at a rate of 6% to 8% per year. Bacteremia, a prerequisite for infective endocarditis (IE), occurs at a rate of 0.7 to 1.4 episodes per 100 patient-care months. Few other medical conditions, except for chemotherapy-induced neutropenia, immunosuppression, and intravenous drug abuse, are associated with higher rates of bacteremia. IE occurs in approximately 2% to 6% of patients receiving HD. The aim of this article is to review the pathogenesis, diagnosis, current therapeutic options, and determinants of prognosis of IE in patients receiving HD.

Vancomycin-resistant enterococci: a road map on how to prevent the emergence and transmission of antimicrobial resistance

Nosocomial acquisition of microorganisms resistant to multiple antibiotics represents a threat to patient safety. Here we review the mechanisms that have allowed highly resistant strains belonging to the Enterococcus genus to proliferate within our health-care institutions. These mechanisms indicate that decreasing the prevalence of resistant organisms requires active surveillance, adherence to vigorous isolation, hand hygiene and environmental decontamination measures, and effective antibiotic stewardship. We suggest how to tailor such a complex, multidisciplinary program to the needs of a particular health-care setting so as to maximize cost-effectiveness.

Infection with antimicrobial-resistant microorganisms in dialysis patients

The prevalence of antimicrobial-resistant microorganisms in various health care settings, including outpatient dialysis facilities, has increased dramatically in the last decade. Antimicrobial use and patient-to-patient transmission of resistant strains are the two main factors that have contributed to this rapid increase. Methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci are commonly isolated as a cause of hemodialysis (HD) catheter-related bacteremia and peritoneal dialysis (PD)-related catheter infection and peritonitis. The widespread use of vancomycin in dialysis patients is of concern because of an increase in the prevalence of vancomycin-resistant enterococci (VRE) in dialysis patients. Staphylococci with reduced sensitivity to vancomycin have also appeared in dialysis patients. A more recent problem is the appearance of S. aureus isolates with a high degree of resistance to the topical antimicrobial agent mupirocin. This has been seen in PD patients who have received prophylactic application of mupirocin at the peritoneal catheter exit site. Appropriate antimicrobial use will help protect the efficacy of currently used antibiotics, such as vancomycin. Published guidelines for use of vancomycin should be followed. New antimicrobials such as linezolid and quinupristin/dalfopristin have activity against VRE and MRSA, but resistance to these agents has already occurred. Preventing transmission of antimicrobial-resistant microorganisms in health care settings, including outpatient dialysis facilities, is important in limiting the spread of these resistant organisms.

Preventing bacterial infections and antimicrobial resistance in dialysis patients

Antimicrobial use, in concert with patient-to-patient transmission of resistant strains, has caused a rapid increase in the prevalence of antimicrobial resistance in recent years. This increase is a particular threat to dialysis patients, who often have been in the forefront of the epidemic of resistance. In this report, which was written in collaboration between the American Society of Nephrology and the Centers for Disease Control and Prevention and has been endorsed by the Executive Council of the Infectious Diseases Society of America, we review and summarize existing clinical practice guidelines and recommendations concerning the prevention, diagnosis, and treatment of certain bacterial infections in dialysis patients and present four strategies to limit the spread of antimicrobial resistance in dialysis patients. First, preventing infection eliminates the need for antimicrobials, thereby reducing selection pressure for resistant strains. Efforts to prevent infection include avoidance of hemodialysis catheters, when possible, and meticulous care of hemodialysis and peritoneal catheters and other hemodialysis vascular access sites. Second, diagnosing and treating infections appropriately can facilitate the use of narrower spectrum agents, rapidly decrease the number of infecting organisms, and reduce the probability of resistance emerging. This entails the collection of indicated specimens for culture and avoidance of contamination of cultures with common skin microorganisms. Third, optimizing antimicrobial use helps protect the efficacy of such critical agents as vancomycin. Published guidelines for the use of vancomycin should be followed, and alternate agents should be used when infections with beta-lactam-resistant bacteria are unlikely or not documented. Fourth, preventing transmission in health care settings is important to limit the spread of resistant organisms. In this regard, such basic measures as glove use and hand hygiene are most important.

Central venous dialysis catheters: catheter-associated infection

Tunneled dialysis catheters (TDC) are extensively used for long-term venous hemodialysis access and their use is frequently associated with infectious complications. Catheter-related bacteremia (CRB) is the most common and important infection associated with TDC use and may be caused by a wide variety of Gram-positive or Gram-negative organisms. Prevention of CRB can be difficult despite use of rigorous infection-control techniques for catheter insertion and access. A number of antibacterial catheter-packing solutions hold promise for reduction of CRB. Treatment of CRB with antibiotics alone yields poor results and may increase the risk for other infectious complications, especially endocarditis. In selected cases where initial infection control can be achieved with antibiotics, guidewire exchange of the TDC results in cure rates equivalent to those of TDC removal and subsequent replacement. Dialysis programs should monitor TDC infections with attention to incidence, bacteriology, and outcomes.

Vancomycin-resistant enterococci colonization in patients at seven hemodialysis centers

BACKGROUND

Vancomycin-resistant enterococci (VRE) are increasing in prevalence at many institutions, and are often reported in dialysis patients. We studied the prevalence of and risk factors for VRE at seven outpatient hemodialysis centers (three in Baltimore, MD, USA, and four in Richmond, VA, USA).

METHODS

Rectal or stool cultures were performed on consenting hemodialysis patients during December 1997 to April 1998. Consenting patients were recultured during May to July 1998 (median 120 days later). Clinical and laboratory data and functional status (1 to 10 scale: 1, normal function; 9, home attendant, not totally disabled; 10, disabled, living at home) were recorded.

RESULTS

Of 478 cultures performed, 20 (4.2%) were positive for VRE. Among the seven centers, the prevalence of VRE-positive cultures varied from 1.0 to 7.9%. Independently significant risk factors for a VRE-positive culture were a functional score of 9 to 10 (odds ratio 6.9, P < 0.001), antimicrobial receipt within 90 days before culture (odds ratio 6.1, P < 0.001), and a history of injection drug use (odds ratio 5.4, P = 0.004).

CONCLUSIONS

VRE-colonized patients were present at all seven participating centers, suggesting that careful infection-control precautions should be used at all centers to limit transmission. In agreement with previous studies, VRE colonization was more frequent in patients who had received antimicrobial agents recently, underscoring the importance of judicious antimicrobial use in limiting selection for this potential pathogen.

Infections in patients with end-stage renal disease. An overview

One of the best kept secrets in medicine is the problem of infections in patients with end-stage renal disease. The prescription of chronic hemodialysis has not reduced the problem of infection; it has only changed the paradigm. Dialysis superimposes myriad new problems onto patients with relentless deterioration from underlying multisystem disease and poor wound healing. All end-stage renal disease and transplant programs require the input from an individual with the specialized knowledge of laboratory diagnosis, pharmacokinetics of antibiotics, antibiotic choice, antimicrobial resistance, infection control, and infection prevention. This article gives an overview of some of the complexities of infectious problems experienced by this unique biological model.