Nasal Carriage of Staphylococcus aureus in Dialysis Patients

Prevention of Catheter Related Infections in Patients on CAPD

Catheter-related infections remain a serious problem for patients on peritoneal dialysis. Such infections can be reduced by careful patient selection and training, by the use of the best connection technology and screening and treating nasal carriage. To date, treatment is less than optimal and therefore, the primary goal should be prevention of catheter-related infections. Prevention is based on improving catheter design and implantation technique, while providing careful exit-site care. Regardless of how it is implemented, we must aggressively pursue the prevention of catheter-related infections by eradicating S.aureus exit-site carriage in PD patients. Based on its effectiveness in adult PD patients, its low rate of adverse effects, and its reasonable cost-effectiveness, application of mupirocin ointment at the exit-site is the current method of choice for preventing PD catheter infections caused byS. aureus. In addition to reducing S. aureus exit-site infections, mupirocin seems to reduce the rates of staphylococcal peritonitis and PD catheter loss. Whether the ointment should be applied in the nares, to the exit-site or both, and whether it should be used only in staphylococcal nasal carriers or all PD patients requires further study.

Peritoneal catheter exit-site infections: predisposing factors, prevention and treatment

Catheter-related infections, exit-site-tunnel infections and peritonitis remain the Achilles heel of peritoneal dialysis. Although the overall incidence of peritoneal-dialysis-related infectious complications has been reduced since the introduction of the Y-set and double bag system, approximately one-fifth of peritonitis episodes are associated with catheter exit-site and tunnel infections. Since its development in 1968, the Tenckhoff catheter has become one of the most widely used peritoneal catheters, and many have proposed that a number of modifications have made it a better choice. Controversies concerning the effect on exit-site infections of catheter(s) with one or two cuffs, with straight, coiled, Swan-Neck, or other modifications led to the randomized controlled studies that are reviewed in this paper. Several studies have confirmed that mupirocin, applied at the exit-site as part of regular exit-site care, reduces the risk of S. aureus exit-site and tunnel infections. Recently, the emergence on a world-wide basis of mupirocin-resistant S. aureus (MuRSA) in peritoneal dialysis patients has brought this prophylactic strategy into question. However the low frequency of resistant organisms after four years of mupirocin prophylaxis suggests that we can continue its use with annual surveillance. Once established, exit-site infections may respond to appropriate treatment, but if not the only option may be catheter removal and replacement. Although peritonitis risk has decreased over the past decade, mainly due to improvements in connection technology, exit-site and tunnel infections have not. An exit-site infection that does not respond to treatment may lead to tunnel infection and to persistent peritonitis, which may require catheter removal and occasionally discontinuation of the peritoneal dialysis. Therefore it is important to be familiar with these factors that predispose to exit-site infection and to know how to prevent and to treat such infections. This review will discuss factors that predispose to catheter-related exit-site infections, techniques of exit-site care, and ways to prevent exit-site infection, with emphasis on S. aureus infections and their treatment.

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.

Preoperative vancomycin prophylaxis decreases incidence of postoperative hemodialysis vascular access infections

The role of vancomycin in the treatment of infected arteriovenous chronic dialysis access is well established. However, the role of preoperative vancomycin administration in preventing infection in newly placed, revised, or surgically thrombectomized grafts has not been determined. We performed a prospective randomized study to examine whether vancomycin prophylaxis can decrease the incidence of postoperative graft infections. Over a 5-year period, 206 patients undergoing 408 permanent vascular access procedures were randomized into two groups. Group 1 (206 procedures) received a single intravenous dose of 750 mg of vancomycin approximately 6 to 12 hours before vascular access placement procedures, while group 2 (202 procedures) did not. Patients were evaluated for access infection within the following 30 days and before use of the access for chronic dialysis. Access infection developed in two patients (1%) in group 1 and in 12 patients (6%) in group 2 (P = 0.006). All 14 infections occurred in upper extremity polytetrafluoroethylene grafts. We conclude that the use of preoperative single-dose intravenous vancomycin prophylaxis for hemodialysis vascular graft procedures reduces the risk of postoperative access infection.

Epidemiological perspective on infections in chronic dialysis patients

Infectious complications are a source of substantial morbidity and a common cause of death among dialysis patients. This article considers the magnitude and impact of the problem of infection among patients treated with hemodialysis (HD) and peritoneal dialysis (PD) using data from national registries and large cohort studies of patients with end-stage renal disease (ESRD). United States Renal Data System (USRDS) data indicate that in the United States for years 1991 to 1992, infection accounted for 12% of all deaths among HD patients and 15% of all deaths among PD patients. Septicemia was the underlying cause in 76% of these infectious deaths among HD patients, of which the vascular access, peritonitis, peripheral vascular disease, and other causes accounted for 12%, 5%, 24%, and 59% respectively. Among PD patients, septicemia accounted for 79% of infectious deaths. Of these deaths attributable to septicemia, peritonitis, peripheral vascular disease, and other causes were reported as the cause in 35%, 23%, and 41% respectively. Infection is also a major cause of morbidity in the dialysis population. Among HD patients, an average of 7.6 bacteremic episodes per 100 patient years (0.076 per year) has been described, of which 48% were associated with access infections. Among PD patients, studies have reported peritonitis rates ranging from 1 in 7.6 to 21.5 months (0.56 to 1.58 per patient year) and exit and/or tunnel infections occurring at a rate of 0.6 episodes per year. The known predictors of infectious complications among these populations are reviewed.