Advancing age and the risk of nasal carriage of Staphylococcus aureus among patients on long-term hospital-based hemodialysis

Extranasal Staphylococcus aureus colonization predisposes to bloodstream infections in patients on hemodialysis with noncuffed internal jugular vein catheters

INTRODUCTION

Staphylococcal infection of endogenous origin is an important cause of morbidity and mortality in patients who receive hemodialysis (HD). The risk of such infections in nasal carriers of the organism is well defined. Extranasal carriage of the organism at extranasal sites may pose similar risks.

METHODS

A total of 70 patients about to undergo internal jugular vein catheterization for HD were enrolled in this prospective observational study. Swab cultures were obtained from anterior nares, posterior pharynx, axillae, toe web spaces, and vascular access sites at baseline and 1 week later. A patient was defined as a persistent carrier when the same organism was grown in both samples. Staphylococcus aureus bloodstream infections were assessed by blood and catheter tip cultures over a 90-day period.

FINDINGS

The mean age of the patients was 43.71 ± 16.2 years. Persistent S. aureus carriage at anterior nares, throat, axilla, toe web spaces, vascular access site, and all sites was documented in 27.9%, 11.4%, 40%, 32.9%, 4.3%, and 64.2% of patients, respectively. Fifteen patients developed S. aureus infections. Catheter related S. aureus infections (CRI) were more likely in persistent carriers than nonpersistent carriers with odds ratios (95% CI) of 10.2 (2.8-37.1), 8.6 (1.7-42.2), 17.3 (3.4-86.0), 3.0 (0.9-9.8), and 1.9 (0.2-22.4) for anterior nares, throat, axilla, toe web spaces, and vascular access site carriers, respectively. The probability of developing CRI in persistent S. aureus carriers was 55% compared to none in noncarriers at 90 days (P = 0.04).

DISCUSSION

Extranasal S. aureus carriage is as significant a risk factor as nasal carriage for staphylococcal infections in patients on HD through catheters. The study is limited by lack of molecular phenotyping.

Epidemiology of haemodialysis catheter complications: a survey of 865 dialysis patients from 14 haemodialysis centres in Henan province in China

OBJECTIVES

To investigate the incidence rates and risk factors for catheter-related complications in different districts and populations in Henan Province in China.

DESIGN

Cross-sectional.

SETTING

Fourteen hospitals in Henan Province.

PARTICIPANTS

865 patients with renal dysfunction undergoing dialysis using catheters between October 2013 and October 2014.

MAIN OUTCOME MEASURES

The main outcome measures were complications, risk factors and patient characteristics. Catheter-related complications included catheter-related infection (catheter exit-site infection, catheter tunnel infection and catheter-related bloodstream infection), catheter dysfunction (thrombosis, catheter malposition or kinking, and fibrin shell formation) and central vein stenosis.

RESULTS

The overall incidence rate was 7.74/1000 catheter-days, affecting 38.61% of all patients, for catheter infections, 10.58/1000 catheter-days, affecting 56.65% of all patients, for catheter dysfunction, and 0.68/1000 catheter-days, affecting 8.79% of all patients, for central vein stenosis. Multivariate analysis showed that increased age, diabetes, primary educational level or below, rural residence, lack of a nephropathy visit before dialysis and pre-established permanent vascular access, not taking oral drugs to prevent catheter thrombus, lower serum albumin levels and higher ferritin levels were independently associated with catheter infections. Rural residence, not taking oral drugs to prevent thrombus, lack of an imaging examination after catheter insertion, non-tunnel catheter type, lack of medical insurance, lack of nephropathy visit before dialysis and pre-established permanent vascular access, left-sided catheter position, access via the femoral vein and lower haemoglobin level were independently associated with catheter dysfunction. Diabetes, lack of nephropathy visit before dialysis and pre-established permanent vascular access, lack of oral drugs to prevent catheter thrombus, left-sided catheter location and higher number of catheter insertions, were independently associated with central vein stenosis.

CONCLUSIONS

The rate of catheter-related complications was high in patients with end-stage renal disease in Henan Province. Our finding suggest that strategies should be implemented to decrease complication rates.

Staphylococcus aureus nasal carriage in hemodialysis centers of Fez, Morocco

BACKGROUND AND OBJECTIVES

Staphylococcus aureus (S. aureus) nasal carriage may be responsible for some serious infections in hemodialyzed patients. The main target of this study was to estimate the prevalence of S. aureus nasal carriage in hemodialysis outpatients and medical staff in hemodialysis centers specifically in Fez region. The second target is to identify the risks of colonization, resistance pattern of isolates and their virulence toxin genes.

PATIENTS AND METHODS

Nasal swab specimens were obtained from 143 hemodialyzed outpatients and 32 medical staff from January to June 2012. Each participant completed a short questionnaire. Nasal carriage of S. aureus was demographically related (age, gender, hemodialysis duration), comorbidity (diabetes, malignancy) and exposure to health care (dialysis staff, hospitalization). PCR (Polymerase Chain Reaction) were used on all the isolates in the research of twelve staphylococcal enterotoxins genes. Also the PCR was used to investigate on the three factors epidermal cell differentiation inhibitors; three exfoliatin toxins; two leukotoxins; the toxic shock syndrome toxin-1 and the hemolysin beta genes.

RESULTS

Nasal screening revealed 38.16%, 50% and 18.75% S. aureus carries in chronic, acute hemodialysis patients and medical staff, respectively. Only young participants were likely to be S. aureus carries (p = 0.002). But there were no gender differences between the isolate carriers and non-carriers or some comorbidity factors such as viral hepatitis B and C, HIV (Human Immunodeficiency Virus) infections, diabetes, chronic smoking, recent hospitalization or antibiotic therapy. Out of all isolates, only one (1.61%) was methicillin-resistant and Twenty-one (33.87%) had at least two virulence toxin genes.

CONCLUSIONS

Knowledge and monitoring of antibiotic resistance profile and virulence of S. aureus carriage are essential in the treatment of infections generated by this pathogen, as well as in the control of clonal dissemination and prevent the spread of S. aureus resistance.

Staphylococcus aureus nasal carriage and patterns of antibiotic resistance in bacterial isolates from patients and staff in a dialysis center of southeast Iran

BACKGROUND AND OBJECTIVES

Staphylococcus aureus is an important infection in hemodialysis patients. We studied the prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and its antibiotic resistance pattern in patients receiving hemodialysis as well as in dialysis unit staff.

MATERIALS AND METHODS

From June to September 2012, we evaluated 74 cases including 61 patients on hemodialysis and 13 dialysis unit staff. Nasal swabs were taken from all cases and were cultured on a blood medium agar. We identified S. aureus based on conventional laboratory methods. For antimicrobial resistance patterns, we used disk diffusion method. Oxacillin MIC, oxacillin and cefoxcitin disk diffusion methods were used for detection of MRSA. Disk approximation test (D-test) was applied for the frequency of erythromycin induced clindamycin resistance.

RESULTS

S. aureus carrier state was determined in 12 of the 61 patients on hemodialysis (19.67%) and 5 of the 13 dialysis unit staffs (38.46%). In hemodialyzed patients, MRSA and MSSA carrier of S. aureus were 6.56% and 13.11%, respectively. All nasal carriage states in studied staffs were MSSA. All isolated S. aureus were found to be sensitive to vancomycin, teicoplanin, and rifampin. However, reduced sensitivity of MRSA isolates to other antibiotics was noted. Resistance frequencies to tested antibiotic was as follows: cefteriaxone and penicillin (100%), tetracycline and doxycilin (75%), gentamicin, cloxacillin, and cefazolin (50%), ciprofloxacin, trimethoprim-sulfamethoxazol, erythromycin, and clindamycin (25%). The resistance rate of isolated MSSA against tested antibiotics was lower than isolated MRSA. Inducible clindamycin resistance was shown in 25% of identified MRSA strains.

CONCLUSION

S. aureus nasal carrier state was lower than former reports from other parts of Iran. The antibiotic resistance patterns also differed, perhaps due to different pattern of administering antibiotics at our hospital. Screening of these patients should be noted as a health priority and microbial sensitivity tests should be considered in order to optimize treatment options.

Meta-analysis of methicillin-resistant Staphylococcus aureus colonization and risk of infection in dialysis patients

Patients undergoing dialysis are particularly vulnerable to methicillin-resistant Staphylococcus aureus (MRSA) infections. We performed a meta-analysis of published studies to estimate the prevalence of MRSA colonization in dialysis patients, time trends, and long-term risk of subsequent MRSA infections. Our search of the PubMed and Embase databases returned 5743 nonduplicate citations, from which we identified 38 relevant studies that included data on 5596 dialysis patients. The estimated prevalence of MRSA colonization was 6.2% (95% confidence interval [95% CI], 4.2% to 8.5%). The prevalence increased over time but remained stable after 2000. Stratification of patients according to dialysis modality and setting revealed that 7.2% (95% CI, 4.9% to 9.9%) of patients on hemodialysis were colonized with MRSA compared with 1.3% (95% CI, 0.5% to 2.4%) of patients on peritoneal dialysis (P=0.01), and that a statistically significant difference existed in the percentage of colonized inpatients and outpatients (14.2% [95% CI, 8.0% to 21.8%] versus 5.4% [95% CI, 3.5% to 7.7%], respectively; P=0.04). Notably, the risk of developing MRSA infections increased among colonized hemodialysis patients compared with noncolonized patients (relative risk, 11.5 [95% CI, 4.7 to 28.0]). The long-term (6-20 months) probability of developing a MRSA infection was 19% among colonized hemodialysis patients compared with only 2% among noncolonized patients. In summary, 6.2% of dialysis patients are MRSA colonized, and the average prevalence of colonization has remained stable since 2000. Colonization in hemodialysis patients is associated with increased risk of MRSA infection.

Staphylococcus colonization, mortality and morbidity in hemodialysis patients: 10 years of observation

Colonization with Staphylococci is widely distributed among patients with end-stage renal disease who are receiving hemodialysis (HD). In addition to more intensive care and use of artificial devices, the incidence of methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection has increased. Such colonization has recently been associated with a more than doubled mortality rate in HD patients. However, it is not clear whether the (presumably increasing) incidence of methicillin-sensitive Staphylococcus aureus (MSSA) colonization is associated with MRSA and/or morbidity and mortality. We therefore established a screening program in our HD population (n=156) and followed these patients over 10 years. We discovered eighty-eight MSSA-colonized patients and one MRSA-colonized patient by cross-sectional and admission-related screenings between 2000 and 2010. The morbidity and mortality of the HD patients was not related to MSSA colonization. The MSSA colonization rate decreased slightly during the 10-year observation period. We conclude that the incidence of MRSA colonization in our unit was lower compared to that reported in the literature. The reasons for this finding are complex and require further investigation. The incidence of MSSA colonization was frequent but did not impact morbidity or mortality.

Staphylococcus aureus nasal carriage in a Moroccan dialysis center and isolates characterization

Staphylococcus aureus, which has its ecological niche in the anterior nares, has been shown to cause a variety of infectious diseases mainly for patients in hemodialysis units. We performed this study to evaluate the prevalence of nasal S. aureus carriage among hemodialysis outpatients, to determine the antimicrobial susceptibility of isolates, to characterize the virulence genes, and to identify associated risk factors. Nares swab specimens were obtained from 70 outpatients on hemodialysis between March and June 2010. Samples were plated immediately onto S. aureus specific media and pattern of antibacterial sensitivity was determined using disk diffusion method. Polymerase chain reaction was used to detect nuc, mecA, and genes encoding staphylococcal toxins. Medical record of patients was explored to determine S.aureus carriage risk factors. Nasal screening identified 42.9% S. aureus carriers with only one (3.3%) methicillin-resistant S. aureus isolate. Among the methicillin-susceptible S. aureus isolates, high rate of penicillin resistance (81.8%) has been detected. The identified risk factors were male gender and age ≤ 30 years. Research of virulence factors showed a high genetic diversity among the 30 S. aureus isolates. Twenty-one (70%) of them had at least one virulence gene, of which 3.3% were Panton-Valentine leukocidin (lukS/F-PV) genes. S. aureus carriage must be screened for at regular intervals in hemodialysis patients. Setting up a bacterial surveillance system is one of the strategies to understand the epidemiology of methicillin-resistant S. aureus, to guide local antibiotic policy and prevent spread of antibiotic-resistant S. aureus.

Epidemiology of end-stage renal disease in the countries of the Gulf Cooperation Council: a systematic review

Objectives

To describe the epidemiology of end stage renal disease (ESRD).

Design

Mixed-methods systematic review.

Setting

The countries of the Gulf Cooperation Council (GCC) which consist of Saudi Arabia, the United Arab Emirates, Kuwait, Qatar, Bahrain, and Oman.

Participants

Defined to have ESRD or patients on regular dialysis for a minimum dialysis period of at least three months. Since many outcomes were reviewed, studies that estimated the incidence and prevalence of ESRD as outcomes should not have defined the study population as ESRD population or patients on regular dialysis. Studies where the study population mainly comprised children or pregnant woman were excluded.

Main outcome measures

The trends of the incidence, prevalence, and mortality rate of ESRD; also, causes of mortality, primary causes and co-morbid conditions associated with ESRD.

Results

44 studies included in this review show that the incidence of ESRD has increased while the prevalence and mortality rate of ESRD in the GCC has not been reported sufficiently. The leading primary causes of ESRD recorded in the countries of the GCC is diabetes with the most prevalent co-morbid conditions being Hypertension and Hepatitis C Virus infection; the most common cause of death was cardiovascular disease and sepsis.

Conclusions

This review highlights that the lack of national renal registries data is a critical issue in the countries of the GCC. The available data also do not provide an accurate and updated estimate for relevant outcomes. Additionally, considering the increasing burden of chronic kidney disease (CKD), these results stressed the needs and the importance of preventative strategies for leading causes of ESRD. Furthermore, more studies are needed to describe the epidemiology of ESRD and for assessing the overall quality of renal care.

Vascular access today

The number of patients with chronic kidney disease requiring renal replacement therapy has increased worldwide. The most common replacement therapy is hemodialysis (HD). Vascular access (VA) has a key role for successful treatment. Despite the advances that have taken place in the field of the HD procedure, few things have changed with regards to VA in recent years. Arteriovenous fistula (AVF), polytetrafluoroethylene graft and the cuffed double lumen silicone catheter are the most common used for VA. In the long term, a number of complications may present and more than one VA is needed during the HD life. The most common complications for all of VA types are thrombosis, bleeding and infection, the most common cause of morbidity in these patients. It has been estimated that VA dysfunction is responsible for 20% of all hospitalizations. The annual cost of placing and looking after dialysis VA in the United States exceeds 1 billion dollars per year. A good functional access is also vital in order to deliver adequate HD therapy. It seems that the native AVF that Brescia and Cimino described in 1966 still remains the first choice for VA. The native forearm AVFs have the longest survival and require the fewest interventions. For this reason, the forearm AVF is the first choice, followed by the upper-arm AVF, the arteriovenous graft and the cuffed central venous catheter is the final choice. In conclusion, VA remains the most important issue for patients on HD and despite the technical improvements, a number of problems and complications have to be resolved.

The frequency of nasal carriage in chronic urticaria patients

OBJECTIVE

Chronic urticaria is characterized by oedema of the skin and mucous membranes. Although many agents have been implicated, aetiology is unknown in 70 to 75% of patients. Infections and foci of chronic infections are most commonly held responsible for chronic urticaria. In this study, the frequency of nasal carriage as the occult focus of infection and sensitivity to antimicrobials are explored in patients with chronic urticaria.

MATERIAL AND METHOD

Ninety-four patients with chronic urticaria and 30 controls participated in the study, which was carried out at the Ege university medical faculty, department of dermatology between January 2004 and January 2005. Nasal swab specimens were taken from the patients and controls and incubated at 37 degrees C degrees for 48 h, and inoculated on standard bacterial medium (blood agar). Antimicrobial susceptibility of a growth from isolates of the nasal swab specimens was conducted. Data were analysed statistically using chi-square and Mann-Whitney U-tests.

RESULTS

Ninety-four patients with chronic urticaria (72.3% female and 27.7% male) and 30 controls (63.3% female and 36.7% male) comprised the study group. Mean age of the patients and controls were 42.6 and 33.8 years, respectively. Staphylococcus aureus was detected in swab specimens from the nasal cavity in 50 of the 94 patients (53.2%) with chronic urticaria and four of the 30 controls (13.3%). Testing revealed that the most susceptible antibiotics were cefaclor, ceftriaxone, amoxycillin-clavulanic acid, amikacin, netilmicin, and fucidic acid.

CONCLUSION

Growth on cultures prepared from nasal swab specimens of chronic urticaria patients was statistically higher than the control group. We detected resistance to growth against mupirocin, an antibiotic frequently used in nasal carriage. High nasal carriage of Staphylococcus aureus in patients with chronic urticaria compared to controls suggests that nasal carriage as a focus of infection should be kept in mind as aetiology.

Prevention of catheter-related bloodstream infections: An appraisal of developments in designing an infection-resistant 'dream dialysis-catheter' (Review Article)

With the increasing number of elderly, diabetics and debilitated patients being accepted for haemodialysis (HD), the use of central venous catheters (CVCs) as vascular access has become more widespread, with an inevitable inherent risk of catheter-related bloodstream infections (CRBSI) and ensuing mortality. No reliable plans for the effective management of CRBSI without actually sacrificing vascular access sites are presently available. Therefore, the onus really falls on renal physicians to make effective use of the established supportive guiding principles, practices, policies and programs to prevent CRBSI among HD patients. A huge body of research in polymer industry has aimed at alterations of physical, chemical, biological and immunological properties of CVCs to prevent the bacterial colonization of catheters. Developing an infection-resistant dialysis catheter has been an elusive dream. This article analyses the current state-of-the-art strategies aimed at preventing CRBSI and also reviews the progress made to date, in the direction of development of a 'bioactive' thrombosis and infection-resistant dialysis catheter.