Effect of Preventing Staphylococcus Aureus Carriage on Rates of Peritoneal Catheter-Related Staphylococcal Infections. Literature Synthesis

Objective

To determine whether specific preventive measures reduce the rate of peritoneal catheter-related infections and peritoneal catheter loss due to Staphylococcus aureus.

Design

Structured literature synthesis.

Methods

Relevant studies were identified by medline search, from personal files, and from the reference lists of retrieved articles. We analyzed English-language studies on treatment targeted at S. aureus, with at least 10 subjects and at least 3 months of follow-up, and data on staphylococcal peritoneal dialysis catheter infections. We excluded noncontrolled studies. Two investigators abstracted data using a structured form.

Results

W e evaluated six studies with concurrent controls and eight studies with historical controls. In one randomized, placebo-controlled, blinded study, periodic nasal mupirocin ointment reduced the rate of staphylococcal exit-site infection from 0.42 to 0.12 episodes/patient-year ( p = 0.006), but had no effect on the rates of staphylococcal tunnel infection, peritonitis, or catheter loss. In one randomized study without placebo control, periodic oral rifampin reduced the rate of staphylococcal exit-site infection from 0.65 to 0.22 epi/pt-yr ( p = 0.011), but had no effect on the rate of staphylococcal peritonitis. In another nonblinded, randomized, controlled study, the use of either rifampin or mupirocin was associated with low rates of staphylococcal catheter infections and catheter loss. In one study with historical controls, the rate of staphylococcal exit-site infection and peritonitis was lower after oral rifampin prophylaxis. In seven other studies comparing nasal or exit-site mupirocin to historical controls, the rate of staphylococcal exit-site infection decreased from 0.17 to 0.05 epi/pt-yr, the rate of staphylococcal peritonitis decreased from 0.18 to 0.06 epi/pt-yr, and the rate of catheter loss decreased from 0.09 to 0.05 epi/pt-yr during the mupirocin period.

Conclusion

The literature provides strong evidence that staphylococcal carriage prophylaxis using either oral rifampin or mupirocin ointment in the nares or exit site reduces significantly the rate of exit-site infection due to Staphylococcus aureus. Weaker evidence based on studies with historical controls suggests that rifampin or mupirocin prophylaxis also reduces the rate of staphylococcal peritonitis and peritoneal catheter loss. Studies with a stronger level of evidence are needed to verify this last point.

Emergence of Mupirocin-ResistantStaphylococcus Aureusin Chronic Peritoneal Dialysis Patients using Mupirocin Prophylaxis to Prevent Exit-Site Infection

Objective

To determine the prevalence of the carriage of Staphylococcus aureus (SA), methicillin-resistant Staphylococcus aureus (MRSA), and mupirocin-resistant Staphylococcus aureus (MuRSA) in chronic peritoneal dialysis (CPD) patients after 4 years of prophylactic mupirocin application to the exit site, in a peritoneal dialysis unit.

Methods

Three swabs were collected from the nares, axillae/groin, and exit site, respectively, from 149 patients on CPD between May and July 2001. All swabs were cultured on solid selective agar (mannitol salt agar) and in mannitol salt broth. Staphylococcus aureus isolates were tested for methicillin resistance using oxacillin screening plates, and mupirocin resistance using E-test strips. Low-level MuRSA was defined as minimum inhibitory concentration (MIC) of 4 mg/mL or more, and high-level MuRSA as MIC of 256 mg/mL or more.

Results

Staphylococcus aureus was isolated from 26 (17%) patients (25 from nares/axilla/groin, and 1 from the exit site). High-level MuRSA was isolated from 4 patients (3% of the total study population; 15% of total SA isolates). No MRSA was detected. One patient with high-level MuRSA had peritonitis due to SA, resulting in treatment failure and catheter loss, soon after the swabs were collected for the study.

Conclusion

We report the emergence of high-level MuRSA in CPD patients after a 4-year practice of continuous use of mupirocin in a small number of patients in our unit. Our results may have significant implications for the future practice of prophylactic use of mupirocin by CPD patients to prevent exit-site infection.

Effect of Local Mupirocin Application on Exit-Site Infection and Peritonitis in an Indian Peritoneal Dialysis Population

Background

Staphylococcus aureus-associated peritonitis and catheter exit-site infections (ESIs) are important causes of hospitalization and catheter loss in patients undergoing chronic peritoneal dialysis. Intranasal and topical use of mupirocin has been found to be an effective strategy in decreasing S. aureus-related infectious complications in persons who are carriers of S. aureus; however, there is no consensus regarding the prophylactic use of mupirocin irrespective of carrier status. We aimed to determine the potential effectiveness of application of mupirocin cream at the catheter exit site in preventing ESI and peritonitis irrespective of carrier status in a tropical country such as India.

Methods

This prospective historically controlled study was done in a total of 40 patients. From August 2003, all patients, incident and prevalent, were instructed to apply 2% mupirocin cream daily to the exit site instead of the older practice of povidone-iodine and gauze dressing. Patients were not screened to determine whether they were S. aureus carriers. The infection-related data for 1 year, until July 2004, were compared with the historical control, which was infection-related data for the year preceding the year of mupirocin application.

Results

Mean age of the study population was 62 years, with 61.8% being male and 64.3% being diabetic. Local application of mupirocin led to a significant reduction in the incidence density per patient-month of both ESI and peritonitis compared to controls (0.15 vs 0.37 and 0.37 vs 0.67, p = 0.01 for both). This amounted to a relative reduction of 60.5% and 55% respectively. ESI and peritonitis due to S. aureus were also significantly lower in the study group compared to controls (incidence density per patient-month 0.05 vs 0.13 and zero vs 0.17 respectively, p < 0.01 for both). There occurred no catheter removal due to infection-related complications during the study period compared to two during the control period. None of the patients reported a mupirocin-related adverse effect.

Conclusions

Daily application of mupirocin at the exit site is a well-tolerated and effective strategy in reducing the incidence of ESI and peritonitis in a tropical country such as India. It can thus significantly reduce morbidity, catheter loss, and transfer to hemodialysis in peritoneal dialysis patients.

Exit-Site Infection in Children on Peritoneal Dialysis: Comparison of Two Types of Peritoneal Catheters

Objective

To review our experience with two types of peritoneal catheters, the standard Tenckhoff catheter and the swan-neck presternal catheter (SNPC).

Design

A retrospective study was undertaken to compare exit-site infection (ESI) rates using two types of peritoneal catheters in children.

Setting

Medical University of Warsaw, Warsaw, Poland.

Patients

During the past 10 years, 60 peritoneal catheters were implanted in 50 children with end-stage renal failure: 46 straight, double-cuffed Tenckhoff in 37 children (mean age 11.8 ± 4.2 years, range 3.1 – 18.5 years), and 14 presternal in 13 children (mean age 10.6 ± 5 years, range 0.3 – 17.7 years). The SNPCs were used in special clinical situations such as recurrent ESI with previous abdominal peritoneal catheters, obesity, presence of ureterocutaneostomies, use of diapers, and young age. For the statistical analysis, only the first catheter placed in each child was chosen: 34 standard Tenckhoff catheters and 9 SNPCs.

Intervention

In all children, peritoneal catheters were implanted surgically under general anesthesia by one surgeon; uniform operative technique and perioperative management was used.

Results

The mean observation time for 46 standard Tenckhoff catheters was 23.8 ± 21.1 months, and for 14 SNPCs 25.1 ± 27.0 months. The ESI rate was 1/17.4 patient-months (0.69 episodes/year) for Tenckhoff catheters and 1/70.2 patient-months (0.17 episodes/year) for SNPCs. The observed differences in ESI rates between the groups reported did not achieve statistical significance.

Conclusions

The risk of ESI may be lower with presternal catheters. Confirmation of these findings requires further prospective clinical investigation in large numbers of patients.

Increasing Mupirocin Resistance of Staphylococcus Aureus in CAPD — Should it Continue to be Used as Prophylaxis?

This editorial summarizes the mechanisms of mupirocin resistance and the conditions that promote its development. While there is increasing evidence that high-level mupirocin resistance is developing during systematic use of mupirocin as prophylaxis against Staphylococcus aureus, the appearance of resistance does not preclude the beneficial effect of regular prophylaxis. Vigilance has to be exercised to notice larger-scale resistance that may require limiting the use of mupirocin.

Staphylococcus Aureus Prophylaxis and Trends in Gram-Negative Infections in Peritoneal Dialysis Patients

Objective

To examine gram-negative exit-site infection and peritonitis rates before and after the implementation of Staphylococcus aureus prophylaxis in peritoneal dialysis (PD) patients.

Design

Prospective data collection with periodic implementation of protocols to decrease infection rates in two PD programs.

Patients

663 incident patients on PD.

Interventions

Implementation of S. aureus prophylaxis, beginning in 1990.

Main Outcome Measures

Rates of S. aureus, gram-negative, and Pseudomonas aeruginosa exit-site infections and peritonitis.

Results

Staphylococcus aureus exit-site infection and peritonitis rates fluctuated without significant trends during the first decade (without prophylaxis), then began to decline during the 1990s subsequent to implementation of prophylaxis, reaching levels of 0.02/year at risk and zero in the year 2000. Gram-negative infections fell toward the end of the 1980s, due probably to the implementation of better connectology. However, there have been no significant changes for the past 6 years. There was little change in P. aeruginosa infections over the entire time period. Pseudomonas aeruginosa is now the most common cause of catheter infection and catheter-related peritonitis.

Conclusions

Prophylaxis against S. aureus is highly effective in reducing the rate of S. aureus infections but has no effect on gram-negative infections. Pseudomonas aeruginosa is now the most serious cause of catheter-related peritonitis.

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.

Clinical Effectiveness of Mupirocin for Preventing Staphylococcus aureus Infections in Nonsurgical Settings: A Meta-analysis

A systematic literature review and meta-analysis was performed to identify effectiveness of mupirocin decolonization in prevention of Staphylococcus aureus infections, among nonsurgical settings. Of the 15 662 unique studies identified up to August 2015, 13 randomized controlled trials, 22 quasi-experimental studies, and 1 retrospective cohort study met the inclusion criteria. Studies were excluded if mupirocin was not used for decolonization, there was no control group, or the study was conducted in an outbreak setting. The crude risk ratios were pooled (cpRR) using a random-effects model. We observed substantial heterogeneity among included studies (I(2) = 80%). Mupirocin was observed to reduce the risk for S. aureus infections by 59% (cpRR, 0.41; 95% confidence interval [CI], .36-.48) and 40% (cpRR, 0.60; 95% CI, .46-.79) in both dialysis and nondialysis settings, respectively. Mupirocin decolonization was protective against S. aureus infections among both dialysis and adult intensive care patients. Future studies are needed in other settings such as long-term care and pediatrics.

Exit-Site Dressing and Infection in Peritoneal Dialysis: A Randomized Controlled Pilot Trial

♦

OBJECTIVE

Peritoneal dialysis (PD)-related infection is a common cause of catheter loss and the main reason for PD drop-out. Exit-site infection (ESI) is a pathway to developing tunnel infection and peritonitis, hence rigorous exit-site care has always been emphasized in PD therapy. The aim of this study was to evaluate the effect of exit-site dressing vs non-dressing on the rate of PD-related infection. ♦

METHODS

A prospective randomized controlled study was conducted in prevalent PD patients at the Hospital Tuanku Jaafar Seremban, Negeri Sembilan, Malaysia, from April 2011 until April 2013. All patients were required to perform daily washing of the exit site with antibacterial soap during a shower. In the dressing group (n = 54), patients were required to clean their exit site using povidone-iodine after drying, followed by topical mupirocin antibiotic application to the exit site. The exit site was then covered with a sterile gauze dressing and the catheter immobilized with tape. In the non-dressing group (n = 54), patients were not required to do any further dressing after drying. They were only required to apply mupirocin cream to the exit site and then left the exit site uncovered. The catheter was immobilized with tape. The primary outcome was ESI. The secondary outcomes were evidence of tunnel infection or peritonitis. ♦

RESULTS

A total of 97 patients completed the study. There were a total of 12 ESI episodes: 4 episodes in 4 patients in the dressing group vs 8 episodes in 4 patients in the non-dressing group. This corresponds to 1 episode per 241.3 patient-months vs 1 episode per 111.1 patient-months in the dressing and non-dressing groups respectively. Median time to first ESI episode was shorter in the non-dressing than in the dressing group, but not significant (p = 0.25). The incidence of gram-positive ESI in both groups was similar. There were no gram-negative ESI in the non-dressing group compared with 2 in the dressing group. The peritonitis rate was 1 per 37.1 patient-month in the dressing group and 1 per 44.4 patient-months in the non-dressing group. Median time to first peritonitis episode was significantly shorter in the dressing group compared to non-dressing (p = 0.03). There was no impact of dressing disruptions in the occurrence of major PD catheter-related infection. ♦

CONCLUSION

Use of a non-dressing technique with only prophylactic topical mupirocin cream application is effective in preventing PD-related infection. The non-dressing technique is more cost-effective and convenient for PD patients, with fewer disposables.

Treatment for peritoneal dialysis-associated peritonitis

BACKGROUND

Peritonitis is a common complication of peritoneal dialysis (PD) that is associated with significant morbidity including death, hospitalisation, and need to change from PD to haemodialysis. Treatment is aimed to reduce morbidity and recurrence. This is an update of a review first published in 2008.

OBJECTIVES

To evaluate the benefits and harms of treatments for PD-associated peritonitis.

SEARCH METHODS

For this review update we searched the Cochrane Renal Group's Specialised Register to March 2014 through contact with the Trials Search Co-ordinator using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE and EMBASE, and handsearching conference proceedings.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs assessing the treatment of peritonitis in PD patients (adults and children). We included any study that evaluated: administration of an antibiotic by different routes (e.g. oral, intraperitoneal (IP), intravenous (IV)); dose of an antibiotic agent; different schedules of administration of antimicrobial agents; comparisons of different regimens of antimicrobial agents; any other intervention including fibrinolytic agents, peritoneal lavage and early catheter removal.

DATA COLLECTION AND ANALYSIS

Multiple authors independently extracted data on study risk of bias and outcomes. Statistical analyses were performed using the random effects model. We expressed summarised treatment estimates as a risk ratio (RR) with 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) with 95% CI for continuous outcomes.

MAIN RESULTS

We identified 42 eligible studies in 2433 participants: antimicrobial agents (36 studies); urokinase (4 studies), peritoneal lavage (1 study), and IP immunoglobulin (1 study). We did not identify any optimal antibiotic agent or combination of agents. IP glycopeptides (vancomycin or teicoplanin) had uncertain effects on primary treatment response, relapse rates, and need for catheter removal compared to first generation cephalosporins, although glycopeptide regimens were more likely to achieve a complete cure (3 studies, 370 episodes: RR 1.66, 95% CI 1.01 to 2.72). For relapsing or persistent peritonitis, simultaneous catheter removal and replacement was better than urokinase at reducing treatment failure rates (RR 2.35, 95% CI 1.13 to 4.91) although evidence was limited to a single small study. Continuous and intermittent IP antibiotic dosing schedules had similar treatment failure and relapse rates. IP antibiotics were superior to IV antibiotics in reducing treatment failure in one small study (RR 3.52, 95% CI 1.26 to 9.81). Longer duration treatment (21 days of IV vancomycin and IP gentamicin) had uncertain effects on risk of treatment relapse compared with 10 days treatment (1 study, 49 patients: RR 1.56, 95% CI 0.60 to 3.95) although may have increased ototoxicity.In general, review conclusions were based on a small number of studies with few events in which risk of bias was generally high; interventions were heterogeneous, and outcome definitions were often inconsistent. There were no RCTs evaluating optimal timing of catheter removal and data for automated PD were absent.

AUTHORS' CONCLUSIONS

Many of the studies evaluating treatment of PD-related peritonitis are small, out-dated, of poor quality, and had inconsistent definitions and dosing regimens. IP administration of antibiotics was superior to IV administration for treating PD-associated peritonitis and glycopeptides appear optimal for complete cure of peritonitis, although evidence for this finding was assessed as low quality. PD catheter removal may be the best treatment for relapsing or persistent peritonitis.Evidence was insufficient to identify the optimal agent, route or duration of antibiotics to treat peritonitis. No specific antibiotic appears to have superior efficacy for preventing treatment failure or relapse of peritonitis, but evidence is limited to few trials. The role of routine peritoneal lavage or urokinase is uncertain.

Prevention of gram-positive infections in peritoneal dialysis patients in Hong Kong: a cost-effectiveness analysis

BACKGROUND

Gram-positive bacteria are the major causative pathogens of peritonitis and exit site infection in patients undergoing peritoneal dialysis (PD). We investigated the cost-effectiveness of regular application of mupirocin at the exit site in PD recipients from the perspective of health care providers in Hong Kong.

METHODS

A decision tree was designed to simulate outcomes of incident PD patients with and without regular application of mupirocin over a 1-year period. Outcome measures included total direct medical costs, quality-adjusted life-years (QALYs) gained, and gram-positive infection-related mortality rate. Model inputs were derived from the literature. Sensitivity analyses evaluated the impact of uncertainty in all model variables.

RESULTS

In a base case analysis, the mupirocin group had a higher expected QALY value (0.6496 vs 0.6456), a lower infection-related mortality rate (0.18% vs 1.64%), and a lower total cost per patient (US $258 vs $1661) compared with the control group. The rate of gram-positive peritonitis without mupirocin and the risk of gram-positive peritonitis with mupirocin were influential factors. In 10,000 Monte Carlo simulations, the mupirocin group had significantly lower associated costs, higher QALYs, and a lower mortality rate 99.9% of the time.

CONCLUSIONS

Topical mupirocin appears to be a cost-effective preventive measure against gram-positive infection in incident patients undergoing PD. The cost-effectiveness of mupirocin is affected by the level of infection risk reduction and subject to resistance against mupirocin.

Prevention of peritoneal dialysis catheter infections in Saudi peritoneal dialysis patients: the emergence of high-level mupirocin resistance

PURPOSE

Exit-site infection (ESI) and peritonitis remain the major causes of morbidity and mortality in peritoneal dialysis (PD) patients. This study compared the effectiveness of local mupirocin ointment and gentamicin cream in preventing both gram-positive and gram-negative bacterial infections in PD patients.

METHODS

Patients from two centers (n = 203) were assigned to daily mupirocin ointment or gentamicin cream application. Infections were tracked prospectively by organisms and expressed as episodes per patient-year for both ESI and peritonitis.

RESULTS

The rate of gram-positive ESI was 0.31/episode/patient-year and 0.22 episodes/patient-year (p<0.05), whereas the rate of gram-negative ESI was 0.28 episode/patient-year and 0.11 episode/patient-year (p<0.01) in the mupirocin group and gentamicin group, respectively. Gram-positive ESI occurred in 17.1% vs 10.2% of patients (p<0.05), whereas 20% of and 5.1% of patients (p<0.001) had gram-negative ESI in the 2 groups respectively. S.aureus was cultured at exit-site in the mupirocin group in 27.8% patients, 60% (16.7% of the total Gram-positive isolates) of them being with high-level mupirocin-resistance. Pseudomonas aeruginosa was cultured in 21.8% of ESI in the mupirocin group, and in only 6.7% in the gentamicin group (p<0.01). Peritonitis rates were lower using gentamicin cream, 0.17 episode/patient-year compared with mupirocin, 0.39 episode/patient-year (p<0.01). With multivariate analysis, only gentamicin exit-site use was a significant predictor for lower catheter infection rate.

CONCLUSION

Prolonged use of mupirocin for ESI-prophylaxis is associated with the emergence of mupirocin-resistant S. aureus. Gentamicin cream is superior to mupirocin ointment in the prevention of PD catheter infections.

The association between exit site infection and subsequent peritonitis among peritoneal dialysis patients

BACKGROUND AND OBJECTIVES

Peritonitis is the most common infectious complication seen in peritoneal dialysis (PD). Traditionally, exit site infection (ESI) has been thought to predispose PD patients to peritonitis, although the risks have not been quantified. This study aimed to quantify the risk of PD peritonitis after ESI.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from 203 clinically stable PD patients >18 years of age who were followed as part of a randomized controlled trial over 18 months were used to estimate the risk of developing peritonitis within 30 days of an ESI compared with individuals who did not have a recent ESI. Sensitivity analyses were performed at 15, 45, and 60 days.

RESULTS

Patients were mostly male (64.5%) and Caucasian, with a mean age of 60.5 ± 14.4 years. There were 44 ESIs and 87 peritonitis episodes during the 18-month study. Seven patients had an ESI followed by peritonitis within 30 days. Using a frailty model, patients who had an ESI had a significantly higher risk of developing peritonitis within 30 days, even if the ESI was appropriately treated. This risk was maximal early on and diminished with time, with hazard ratios (95% confidence interval) of 11.1 at 15 days (HR=11.1, 95% CI=4.9-25.1), 5.3 at 45 days (2.5-11.3), and 4.9 at 60 days (2.4-9.9). In 2.3% of patients, subsequent peritonitis was caused by the same organism as the previous ESI.

CONCLUSIONS

A strong association between a treated ESI and subsequent PD peritonitis was present up to 60 days after initial diagnosis.

Prevention of peritoneal dialysis-related infections

Despite substantial advances in peritoneal dialysis (PD) as a renal replacement modality, PD-related infection remains an important cause of morbidity, technique failure, and mortality. This review describes the microbiology and outcomes of PD peritonitis and catheter infection, followed by a discussion of several strategies that may reduce the risk of PD-related infections. Strategies that are reviewed include use of antibiotics at the time of PD catheter insertion, selection of PD catheter design and insertion technique, patient training, PD connectology, exit site prophylaxis, periprocedural prophylaxis, fungal prophylaxis, and choice of PD solutions.

The impact of treatment modality on infection-related hospitalization rates in peritoneal dialysis and hemodialysis patients

BACKGROUND AND OBJECTIVES

Infection is a major cause of morbidity and mortality in the dialysis population. This study compares the rates of infection-related hospitalization (IRH) in incident chronic dialysis patients initiating outpatient peritoneal dialysis (PD) and hemodialysis (HD).

METHODS AND PATIENTS

This was a retrospective cohort study at the dialysis program of a tertiary-care center in Toronto, Canada. Incident chronic dialysis patients that were eligible for both PD and HD and started outpatient dialysis between 1 January 2004 and 31 August 2008 were included. Dialysis modality was assigned at the start of outpatient dialysis treatment. All hospital admissions were reviewed and incidence of IRH was compared between PD and HD using Poisson regression.

RESULTS

Of 264 incident chronic dialysis patients, 168 (64%) were eligible for both treatment modalities: 71 (42%) started outpatient PD and 97 (58%) started outpatient HD. The unadjusted and adjusted incidence rate ratios (IRR) of IRH did not differ significantly between PD and HD: 1.23 [95% confidence interval (CI) 0.65-2.32, p=0.37] and 1.14 (95% CI 0.58-2.23, p=0.71) respectively. There was no difference between PD and HD in the risk of access loss (28% vs 35%, p=0.73), modality change (22% vs 0%, p=0.10), or death (17% vs 6%, p=0.60) following hospitalization for infection. Patients starting outpatient treatment on PD versus HD were more likely to be hospitalized for peritonitis (IRR 3.20, 95% CI 1.16-9.09; p=0.029) and there was a trend for fewer hospitalizations for bacteremia (IRR 0.19, 95% CI 0.028-1.30; p=0.091). The risk of IRH did not differ between PD and HD in the subgroup of patients that received adequate predialysis care (IRR 1.16, 95% CI 0.59-2.27; p=0.67) or when patients starting outpatient HD with a central venous catheter were excluded (IRR 1.52, 95% CI 0.53-4.37; p=0.44).

CONCLUSIONS

Patients that initiate outpatient peritoneal dialysis do not have a significantly increased risk of infection-related hospitalization compared to those that initiate outpatient hemodialysis.

Mupirocin application at the exit site in peritoneal dialysis patients: five years of experience

INTRODUCTION

In this study, we aimed to analyze the effects of once- or thrice-weekly mupirocin application on peritonitis, exit-site infection (ESI), and antibiotic resistance with mupirocin.

PATIENTS AND METHODS

By 2000 mupirocin began to be applied once a week to 33 patients who previously did not use mupirocin at the exit site. By the beginning of 2002, the patients were assigned to two groups. In group I patients continued to apply mupirocin once a week. In group II patients began to apply mupirocin to the exit site three times weekly and we began to obtain cultures from the nares, inguinal area, axillae, and the exit site.

RESULTS

A total of 28 episodes of ESI and 41 episodes of peritonitis were seen in 33 patients prior to mupirocin treatment, while a total of 14 episodes of ESI and 34 episodes of peritonitis were observed in all groups of patients who used mupirocin. In a subgroup analysis, 13 episodes of peritonitis and 7 episodes of ESI were determined in group I, while 6 episodes of peritonitis and 1 episode of ESI were determined in group II. Staphylococcus aureus reproduction rate and mupirocin resistance were 2.11 and 0.2%, respectively. Coagulase-negative staphylococcus reproduction rate was 70.56% (MuR: 59.87% and MeR: 33.7%) and 72.6% (MuR: 64.7% and MeR: 33.3%) in groups I and II, respectively.

CONCLUSION

Mupirocin application at the exit sites reduces peritonitis and ESI to a considerable amount, and thrice-weekly application of mupirocin seems to be more efficient compared to once-weekly application.

The future of peritoneal dialysis in the United States: optimizing its use

Peritoneal dialysis (PD) has been used to treat patients with stage V chronic kidney disease since 1976. However, despite this long history, as of 2008 <8% of prevalent ESRD patients in the United States are treated with PD, a modality mix that is significantly different from what is seen in other developed countries. Data are reviewed that suggest that the reasons for this seem to be caused by non-medical-related issues such as subtle differences in practice patterns and unintended financial considerations. Medical outcome date would seem to favor more utilization of PD. For instance, data from the USRDS suggested that the relative risk of death for PD versus center hemodialysis has been improving, tending to favor those on PD for longer and longer periods of time. Infectious complications have also been markedly reduced. It is anticipated that changes in government reimbursement, such as the bundling of dialysis-related services, will stimulate a renewed interest in home therapies. Currently most home dialysis units are small, and some have minimal clinical experience with PD. If trends in reimbursement do favor a renewed interest in PD, for patient outcomes on PD to continue to improve, there will likely need to be further educational activities focused on PD, and perhaps, consolidation of PD programs may needed.

Topical mupirocin/sodium hypochlorite reduces peritonitis and exit-site infection rates in children

BACKGROUND AND OBJECTIVES

Peritoneal dialysis (PD) is a common maintenance renal replacement modality for children with ESRD frequently compromised by infectious peritonitis and catheter exit site and tunnel infections (ESI/TI). The effect of topical mupirocin (Mup) and sodium hypochlorite (NaOCl) solution was evaluated as part of routine daily exit site care on peritonitis and ESI/TI rates, causative microorganisms, and catheter survival rates.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Retrospective chart review of children on home continuous cycling PD between April 1, 2001 and June 30, 2007 was performed. Infection rates were examined based on exit site protocol used in two different periods: Mup alone, April 1, 2001 to November 17, 2004; and Mup and NaOCl (Mup+NaOCl), November 18, 2004 to June 30, 2007.

RESULTS

Eighty-three patients (mean PD initiation age: 12.1 +/- 5.8 yr) received home PD over 2009 patient months. Annualized rates (ARs) for peritonitis decreased from 1.2 in the Mup period to 0.26 in the Mup+NaOCl period (P < 0.0001). ARs for ESI/TI decreased from 1.36 in the Mup period to 0.33 in the Mup+NaOCl period (P < 0.0001). No infections with Mup-resistant organisms were observed when either Mup or Mup+NaOCl was used for prophylaxis. Gram-negative-organism associated peritonitis decreased from an AR of 0.31 in the Mup period to 0.07 in the Mup+NaOCl period (P < 0.001). Infection-related catheter removal rates decreased from 1 in 38.9 catheter-months in the Mup period to 1 in 94.2 in the Mup+NaOCl period (P = 0.01). Catheter survival rates were longer in the Mup+NaOCl period (Kaplan-Meier, P < 0.009).

CONCLUSIONS

The combination Mup+NaOCl in daily exit site care was very effective to reduce PD catheter-associated infections and prolong catheter survival in pediatric patients.

Mupirocin for preventing exit-site infection and peritonitis in patients undergoing peritoneal dialysis

OBJECTIVES

Recently, there have been increasing concerns about the emergence of mupirocin resistance and increased infections due to lowered inhibition of Staphylococcus aureus. We conducted this systemic analysis to find out whether the application of mupirocin was effective for the prevention of exit-site infection (ESI) and peritonitis in patients undergoing peritoneal dialysis (PD).

METHODS

Recruited studies met the following criteria: they were randomized controlled trials or historical cohort studies; subjects consisted of adults (age, >or= 18 years) undergoing PD; mupirocin treatment was administered to the therapy group and placebo or no treatment was administered to the control group. The primary extracted data were the difference in the episodes of ESI and peritonitis S. aureus or other organisms among treatment and control groups. Results. Fourteen studies described in 13 articles and a total of 1,233 patients versus 1,217 controls were included in the analysis. Of the 13 articles, 6 were newly published articles that had not been analysed previously and 3 were randomized controlled trials. The application of mupirocin decreased the risk by 72% [95% confidence interval (CI): 0.60-0.81] in ESI and by 70% (95% CI 0.52-0.81) in peritonitis due to S. aureus among all patients undergoing PD. Treatment of mupirocin reduced the risks of ESI and peritonitis due to all organisms by 57% (95% CI: 0.46-0.66) and 41% (95% CI: 0.24-0.54), respectively. Based on the six newly published articles, the reduced risk rate for mupirocin therapy was found to be 80% (95% CI: 0.39-0.93, P = 0.004) in ESI and 91% (95% CI: 0.72-0.97, P < 0.0001) in peritonitis due to S. aureus; 70% (95% CI: 0.47-0.82, P < 0.0001) in ESI and 42% (95% CI: 0.25-0.55, P < 0.0001) in peritonitis due to all organisms among mupirocin-treated and -untreated subjects. Based on the three randomized controlled trials, ESI and peritonitis due to S. aureus were found to be reduced by 73% (95% CI: 0.63-0.80, P < 0.0001) and 40% (95% CI: 0.17-0.56, P = 0.002), respectively. Interestingly, although mupirocin treatment can reduce the risk rate of ESI by 46% (95% CI: 0.35-0.55, P < 0.00001), it cannot decrease the risk rate of peritonitis due to all organisms (P = 0.56).

CONCLUSIONS

Mupirocin prophylaxis was effective on preventing ESI and peritonitis due to S. aureus and other organisms in PD patients.

The role of nasal carriage in Staphylococcus aureus burn wound colonization

Thermal injury destroys the physical skin barrier that normally prevents invasion of microorganisms. This and concomitant depression of local and systemic host cellular and humoral immune responses are important factors that contribute to colonization and infection of the burn wound. One of the most common burn wound pathogens is Staphylococcus aureus. Staphylococcus aureus is both a human commensal and a frequent cause of infections leading to mild to life-threatening diseases. Despite a variety of infection control measures, for example patient cohorting and contact precaution at burn centres, S. aureus is still frequently encountered in burn wounds. Colonization with S. aureus has been associated with delayed wound healing, increased need for surgical interventions, and prolonged length of stay at burn centres. In this minireview, we focus on S. aureus nasal carriage in relation to S. aureus burn wound colonization and subsequent infection, and its impact on strategies for infection control.

Prevention of infectious complications in peritoneal dialysis: best demonstrated practices

Peritoneal dialysis (PD) related infections continue to be a serious complication for PD patients. Peritonitis can be associated with pain, hospitalization and catheter loss as well as a risk of death. Peritonitis risk is not evenly spread across the PD population or programs. Very low rates of peritonitis in a program are possible if close attention is paid to the causes of peritonitis and protocols implemented to reduce the risk of infection. Protocols to decrease infection risk in PD patients include proper catheter placement, exit-site care that includes Staphylococcus aureus prophylaxis, careful training of patients with periodic retraining, treatment of contamination, and prevention of procedure-related and fungal peritonitis. Extensive data have been published on the use of antibiotic prophylaxis to prevent exit site infections. There are fewer data on training methods of patients to prevent infection risk. Quality improvement programs with continuous monitoring of infections, both of the catheter exit site and peritonitis, are important to decrease the PD related infections in PD programs. Continuous review of every episode of infection to determine the root cause of the event should be routine in PD programs. Further research is needed examining approaches to decrease infection risk.

Efficacy of a non-vancomycin-based peritoneal dialysis peritonitis protocol

BACKGROUND

Peritonitis has a significant impact upon morbidity and mortality of peritoneal dialysis (PD) patients. Gram-positive organisms account for the majority of infections and vancomycin is a cost effective broad-spectrum antimicrobial treatment for PD peritonitis, but this may lead to the emergence of multiple antibiotic-resistant organisms. The purpose of the present paper was to evaluate the efficacy of a non-vancomycin-based protocol comprising cephazolin and gentamicin, which was introduced in the present PD population as empirical treatment for peritonitis.

METHODS

The study involved 82 peritonitis episodes over a 4-year period in 58 patients, excluding those with previous methicillin-resistant staphylococcal peritonitis.

RESULTS

With cephazolin and gentamicin there was no apparent difference in response or relapse rates in comparison to reported studies using vancomycin-based first-line therapy protocols.

CONCLUSION

We advocate initial treatment of PD peritonitis with non-vancomycin-based therapy given similar efficacy and the potential for reduction of resistant organisms.

The impact of topical mupirocin on peritoneal dialysis infection in Singapore General Hospital

BACKGROUND

Peritonitis and exit-site infections (ESI) are major causes of morbidity in peritoneal dialysis (PD) patients. The application of topical mupirocin to exit sites reduces such complications, and prolongs life in PD. Since the year 2000, this topical treatment has been used in our hospital on new PD patients. We analysed the results of this protocol, and studied the effects of comorbidities on the incidence of peritonitis.

METHODS

We studied 740 incident PD patients, who were divided into two groups based on year of entry into PD (Group 1 from January 1998 to December 1999 inclusive, topical mupirocin not used, and Group 2 from January 2000 to March 2004 inclusive, topical mupirocin used). The variables we studied included gender, age, diabetic status, ischaemic heart disease, peripheral vascular disease, cerebrovascular disease and serum albumin.

RESULTS

The application of topical mupirocin at the exit site led to a significant reduction in the rate of peritonitis (0.443 vs 0.339 episodes per patient-year; P<0.0005) and in ESI (0.168 vs 0.156 episodes per patient-year; P<0.005), results attributed primarily by the significant (P<0.005) reduction in Staphylococcus aureus infection. There was also an unexpected lowering of Pseudomonas aeruginosa peritonitis in the mupirocin group (P<0.005). Stepwise multiple logistic regression analysis revealed that only the application of mupirocin and serum albumin levels were significant predictors of peritonitis.

CONCLUSIONS

Our study, although retrospective, has demonstrated that the topical use of mupirocin was associated with a significant reduction in ESI and peritonitis and, unexpectedly, with findings of fewer incidences of Pseudomonas peritonitis. Serum albumin level before the initiation of PD was a strong predictor of subsequent peritonitis. Mupirocin, with its low toxicity, ease of application and demonstrable beneficial effect in reducing ESI and peritonitis is now used on all of our incident PD patients.

The impact of topical mupirocin on peritoneal dialysis infection rates in Singapore General Hospital

BACKGROUND

Peritonitis and exit-site infections (ESI) are major causes of technique failure and morbidity in peritoneal dialysis (PD) patients. Topical mupirocin on the exit-site has been shown to reduce such complications and prolong life in PD. Since the year 2000, such an approach has been adopted for our new incident PD population. We now report the results of this new protocol. We also studied the effect of co-morbidity on peritonitis occurrence.

METHODS

A total of 740 incident PD patients were studied. Patients were divided into two groups based on year of entry into PD (Group 1 from January 1998-December 1999 without topical mupirocin and Group 2 from January 2000-March 2004 with topical mupirocin). Variables studied included gender, age, diabetic status, ischaemic heart disease, peripheral vascular disease, cerebrovascular disease and serum albumin.

RESULTS

Topical mupirocin at the exit-site has led to a significant reduction in peritonitis rate (0.443 vs 0.339 episodes/patient-year; P<0.0005) and ESI (0.168 vs 0.156 episodes/patient-year; P<0.005) attributed primarily to the significant reduction in Staphylococcus aureus infections. There was an unexpected finding of lower Pseudomonas aeruginosa peritonitis in the mupirocin group (P<0.005). Stepwise multiple logistic regression analysis revealed that only mupirocin application and serum albumin were significant predictors of peritonitis.

CONCLUSIONS

Our study, although limited by its retrospective nature, demonstrated that topical mupirocin was associated with a significant reduction in ESI and peritonitis with unexpected findings of lower Pseudomonas peritonitis. Serum albumin prior to the initiation of PD was a strong predictor of subsequent peritonitis. Mupirocin, with its low toxicity, ease of application and demonstrable beneficial effect in reducing ESI and peritonitis is now used on all incident PD patients.

Randomized, double-blind trial of antibiotic exit site cream for prevention of exit site infection in peritoneal dialysis patients

Infection is the Achilles heel of peritoneal dialysis. Exit site mupirocin prevents Staphylococcus aureus peritoneal dialysis (PD) infections but does not reduce Pseudomonas aeruginosa or other Gram-negative infections, which are associated with considerable morbidity and sometimes death. Patients from three centers (53% incident to PD and 47% prevalent) were randomized in a double-blinded manner to daily mupirocin or gentamicin cream to the catheter exit site. Infections were tracked prospectively by organism and expressed as episodes per dialysis-year at risk. A total of 133 patients were randomized, 67 to gentamicin and 66 to mupirocin cream. Catheter infection rates were 0.23/yr with gentamicin cream versus 0.54/yr with mupirocin (P = 0.005). Time to first catheter infection was longer using gentamicin (P = 0.03). There were no P. aeruginosa catheter infections using gentamicin compared with 0.11/yr using mupirocin (P < 0.003). S. aureus exit site infections were infrequent in both groups (0.06 and 0.08/yr; P = 0.44). Peritonitis rates were 0.34/yr versus 0.52/yr (P = 0.03), with a striking decrease in Gram-negative peritonitis (0.02/yr versus 0.15/yr; P = 0.003) using gentamicin compared with mupirocin cream, respectively. Gentamicin use was a significant predictor of lower peritonitis rates (relative risk, 0.52; 95% confidence interval, 0.29 to 0.93; P < 0.03), controlling for center and incident versus prevalent patients. Gentamicin cream applied daily to the peritoneal catheter exit site reduced P. aeruginosa and other Gram-negative catheter infections and reduced peritonitis by 35%, particularly Gram-negative organisms. Gentamicin cream was as effective as mupirocin in preventing S. aureus infections. Daily gentamicin cream at the exit site should be the prophylaxis of choice for PD patients.

Routine use of mupirocin at the peritoneal catheter exit site and mupirocin resistance: still low after 7 years

OBJECTIVE

The purpose of this study (the third in a series of similar studies) is to evaluate the prevalence of Staphylococcus aureus (SA), methicillin-resistant SA (MRSA) and mupirocin-resistant SA (MuRSA) carriers in a peritoneal dialysis centre where patients have been instructed to use prophylactic mupirocin ointment at the catheter exit site over the last 7 years.

METHODS

Swabs were taken from catheter exit site, nares, axillae and groin in 147 chronic peritoneal dialysis out-patients between November 2003 and January 2004. Axillae/groin and nasal samples were pooled and cultured in the same medium, whereas exit site swabs were cultured separately. All SA isolated were tested for methicillin and mupirocin resistance using oxacillin screening plates and E-test strips.

RESULTS

Sixteen of 147 patients (10.9%) were found to be SA carriers: of these 13 (8.8%) had a positive nasal/axillae/groin culture; two (1.4%) had both nasal/axillae/groin- and exit site-positive culture; and one (0.7%) had only exit site-positive culture. In these 16 SA carriers, we found mupirocin-resistant strains (MuRSA) in four patients (25%) and MRSA in two patients (12.5%). Among the four MuRSA carriers, one had both nasal/axillae/groin- and exit site-positive culture and three had only nasal/axillae/groin-positive culture. Three high-level resistance and one low-level resistance MuRSA carriers were isolated. One MuRSA strain was also methicillin resistant. All MRSA strains were sensitive to vancomycin and rifampicin.

CONCLUSION

After 7 years' routine use of prophylactic mupirocin ointment at the catheter exit site in non-selected chronic peritoneal dialysis patients, MuRSA was found in 25% of SA strains isolated or in 2.7% of the patients. Compared with our previous study, 3 years earlier, there is no significant increase in the MuRSA prevalence in peritoneal dialysis patients who routinely apply mupirocin ointment at the catheter exit site.

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.

Mupirocin prophylaxis to prevent Staphylococcus aureus infection in patients undergoing dialysis: a meta-analysis

A systematic review of the English-language literature was performed to determine the overall benefit of mupirocin therapy in reducing the rate of Staphylococcus aureus infection among patients undergoing hemodialysis (HD) or peritoneal dialysis (PD). Included studies met the following criteria: they were randomized clinical trials or cohort studies; cohorts consisted of adults (age, > or =18 years) requiring HD or PD; mupirocin therapy was administered to the treatment group, and placebo or no therapy was administered to the control group; and the primary outcome of interest was the difference in the number of S. aureus infections among mupirocin-treated and -untreated patients. Ten studies described in 9 articles were analyzed. A total of 2445 patients were included in the analysis. Use of mupirocin reduced the rate of S. aureus infections by 68% (95% confidence interval [CI], 57%-76%) among all patients undergoing dialysis; risk reductions were 80% (95% CI, 65%-89%) among patients undergoing HD and 63% (95% CI, 50%-73%) among patients undergoing PD. When data were stratified by type of infection, S. aureus bacteremia was found to be reduced by 78% among patients undergoing HD, and peritonitis and exit-site infections were found to be reduced by 66% and 62%, respectively, among patients undergoing PD. Mupirocin prophylaxis substantially reduces the rate of S. aureus infection in the dialysis population. Optimal regimens that minimize the emergence of mupirocin resistance need to be explored.

Clinical effectiveness of different approaches to peritoneal dialysis catheter exit-site care

OBJECTIVE

The objective of this review was to appraise and synthesise the best available evidence on the clinical effectiveness of peritoneal dialysis catheter exit-site care.

INCLUSION CRITERIA

This review considered all randomised controlled trials that evaluated the effectiveness of peritoneal exit-site care. In the absence of randomised controlled trials, other controlled research designs such as non-randomised controlled trials were considered for inclusion in a narrative summary to enable the identification of current approaches and possible future strategies. Participants of interest were adults with chronic renal failure on maintenance peritoneal dialysis. Interventions of interest were those used to manage peritoneal catheter exit sites, and included types of dressings, frequency of dressings, types of skin care, and use of topical antiseptic or antimicrobial agents.

SEARCH STRATEGY

The search sought to find both published and unpublished studies. An initial limited search of MEDLINE and CINAHL databases was undertaken to identify key words contained in the title or abstract, and index terms used to describe relevant articles. A second extensive search was undertaken using all identified key words and index terms. The third step was a search of the reference lists and bibliographies of all relevant articles.

METHODOLOGICAL QUALITY

All identified studies that met the inclusion criteria were assessed for methodological validity by two reviewers prior to inclusion in the review. Critical appraisal of studies focused on identifying bias in selection, performance, attrition and detection.

RESULTS

This review found few studies of sufficient quality to meet the inclusion criteria. The included studies often utilised historical control groups, potentially confounding measurement of their outcomes. The outcome measures varied considerably, thus meta-analysis was not possible.

CONCLUSIONS

This review suggests topical mupirocin may reduce the risk of exit-site infection; however, the clinical effectiveness of any one antibiotic, antiseptic or dressing procedure was not established for the prevention or reduction of exit-site infection rates or peritonitis. This review has underlined large gaps in the existing knowledge on the care of exit sites in patients on peritoneal dialysis.

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.

Mupirocin resistance after long-term use for Staphylococcus aureus colonization in patients undergoing chronic peritoneal dialysis

Mupirocin (Mup) has been used extensively to prevent Staphylococcus aureus (SAu) infections in patients undergoing peritoneal dialysis (PD). Resistance to Mup has been reported, but its relevance after long-term use of this drug in PD is unknown. Colonization by SAu was treated with topic Mup in our unit between September 1990 and December 2000. Sensitivity to Mup was tested in 437 strains of SAu isolated from 155 PD patients and 62 dialysis partners. Resistance to Mup was classified as low (minimal inhibitory concentration [MIC] > or = 8 microg/mL) or high (MIC > or = 512 microg/mL) degree. MIC90 was 0.125 microg/mL in 1990 to 1996 (5% low, 0% high-degree resistance), 64 microg/mL in 1997 to 1998 (6.6% low, 8.3% high-degree resistance), and 1,024 microg/mL in 1999 to 2000 (2.3% low, 12.4% high-degree resistance). Mup-resistant SAu were isolated from 25 patients and 13 partners a median of 15 months after starting PD. Resistance was associated frequently with repeated treatments of SAu recolonization, but was detected in 3 cases at the start of PD therapy. The accumulated incidence of SAu exit-site infection in the period 1997 to 2000 was 32.3% in patients colonized by Mup-resistant SAu as compared with 14.5% in those colonized by Mup-sensitive SAu (P = 0.03). Mup-resistant SAu have emerged in a significant proportion of our PD patients and dialysis partners. This emergence has resulted in a moderate, but significant, increase in the risk of SAu exit-site infection and raises concerns about the future of Mup as the therapy of choice for SAu colonization in patients undergoing chronic PD.