Genetic Identification of Methicillin-Resistant Staphylococcus aureus Nasal Carriage and Its Antibiogram among Kidney Dialysis Patients at a Tertiary Care Hospital in AL-Karak, Jordan

Background. Methicillin-resistant Staphylococcus aureus (MRSA) is a major bacterial pathogen. Aim. The present study aimed to determine the incidence of MRSA infections among kidney dialysis patients and the antibiotic susceptibility patterns and investigate the prevalence of mecA gene among MRSA isolates. Materials and Methods. A total of 83 nasal sterile cotton swabs samples were obtained from hemodialysis patients from Al-Karak Governmental Hospital, Al-Karak, Jordan. Collected and cultured on nutrient agar and mannitol salt agar and incubating at 37°C for 24–48 hours, Staphylococcus aureus (S. aureus) strains were identified by gram stain, coagulase test, and catalase tests. The MRSA isolates were tested for the presence of MecA and SCCmec genes using the Xpert SA Nasal Complete assay real-time PCR. Factors such as age and gender were included in the study. The antibiotic profile tested by using the disc diffusion method tested all MRSA isolates. Results. This study showed that 10.8% of the cultures’ growth was S. aureus and 9.6% of all the patients were infected with MRSA, with no relationship between the number and frequency of MRSA according to the patient’s gender or age. All MRSA (100%) isolates have both genes (MecA genes and SCCmec genes), and all samples were resistant to oxacillin, ceftazidime, cefoxitin, aztreonam, and ampicillin. Conclusion. The MRSA prevalence was determined among kidney dialysis patients in the hospital. All positive samples were resistant to oxacillin, ceftazidime, cefoxitin, aztreonam, and ampicillin, which is a very rare finding, and this will give the scientists and doctors a dangerous indication about health-care centers in the Al-Karak city of Jordan.

Methicillin-resistant Staphylococcus aureus nasal carriage among patients on haemodialysis with newly inserted central venous catheters

BACKGROUND

Although methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization is common among end-stage kidney disease patients undergoing haemodialysis, few studies were focused on MRSA nasal carriers among haemodialysis patients with central venous catheters (CVCs). The aim of this study is to evaluate the risk factors, various clinical outcomes and effect of decolonization for MRSA nasal colonization among patients on haemodialysis via CVCs.

METHODS

This was a single-centre non-concurrent cohort study of 676 patients who had new haemodialysis CVCs inserted. They were all screened for MRSA colonization via nasal swabs and were categorized into two groups: MRSA carriers and MRSA noncarriers. Potential risk factors and clinical outcomes were analysed in both groups. All MRSA carriers were given decolonization therapy and the effect of decolonization on subsequent MRSA infection was also performed.

RESULTS

Eighty-two patients (12.1%) were MRSA carriers. Multivariate analysis showed that MRSA carrier (OR 5.44; 95% CI 3.02-9.79), long-term care facility resident (OR 4.08; 95% CI 2.07-8.05), history of Staphylococcus aureus infection (OR 3.20; 95% CI 1.42-7.20) and CVC in situ > 21 days (OR 2.12; 95% CI 1.15-3.93) were independent risk factors for MRSA infection. There was no significant difference in all-cause mortality between MRSA carriers and noncarriers. The MRSA infection rates were similar between MRSA carriers with successful decolonization and those who had failed/incomplete decolonization in our subgroup analysis.

CONCLUSION

MRSA nasal colonization is an important cause of MRSA infection among haemodialysis patients with CVCs. However, decolonization therapy may not be effective in reducing MRSA infection.

MRSA compendium of epidemiology, transmission, pathophysiology, treatment, and prevention within one health framework

Staphylococcus aureus is recognized as commensal as well as opportunistic pathogen of humans and animals. Methicillin resistant strain of S. aureus (MRSA) has emerged as a major pathogen in hospitals, community and veterinary settings that compromises the public health and livestock production. MRSA basically emerged from MSSA after acquiring SCCmec element through gene transfer containing mecA gene responsible for encoding PBP-2α. This protein renders the MRSA resistant to most of the β-lactam antibiotics. Due to the continuous increasing prevalence and transmission of MRSA in hospitals, community and veterinary settings posing a major threat to public health. Furthermore, high pathogenicity of MRSA due to a number of virulence factors produced by S. aureus along with antibiotic resistance help to breach the immunity of host and responsible for causing severe infections in humans and animals. The clinical manifestations of MRSA consist of skin and soft tissues infection to bacteremia, septicemia, toxic shock, and scalded skin syndrome. Moreover, due to the increasing resistance of MRSA to number of antibiotics, there is need to approach alternatives ways to overcome economic as well as human losses. This review is going to discuss various aspects of MRSA starting from emergence, transmission, epidemiology, pathophysiology, disease patterns in hosts, novel treatment, and control strategies.

Epidemiology and management of healthcare-associated bloodstream infections in non-neutropenic immunosuppressed patients: a review of the literature

Advancements in medicine have led to a considerable increase in the proportion of patients living with severe chronic diseases, malignancies, and HIV infections. Most of these conditions are associated with acquired immune-deficient states and treatment-related immunosuppression. Although infections as a result of neutropenia have long been recognized and strategies for management were developed, non-neutropenic immunosuppression has been overlooked. Recently, community-acquired infections in patients with frequent, significant exposure to healthcare settings and procedures have been classified as 'healthcare-associated infections' since they are more similar to hospital-acquired infections. Most of the non-neutropenic immunosuppressed patients have frequent contact with the healthcare system due to their chronic and severe diseases. In this review, we focus on the healthcare-associated bloodstream infections in the most common non-neutropenic immunosuppressive states and provide an update of the recent evidence for the management of these infections.

Body site Staphylococcus aureus colonization among maintenance hemodialysis patients

BACKGROUND

Patients on maintenance hemodialysis therapy are at high risk for health care-associated infections. Staphylococcus aureus is a common cause of health care-associated infections among maintenance hemodialysis patients. It is established that S. aureus colonization is associated with an increased risk for subsequent infection in this population. There is an increasing number of reports that extranasal S. aureus colonization is more common than previously believed and in certain body sites even more common than nasal colonization. There are few data describing extranasal colonization among maintenance hemodialysis patients.

METHODS

We surveyed 100 patients at 3 body sites (anterior nares, oropharynx, and inguinal region) for S. aureus colonization. Participants were also administered a standardized survey to assess risk factors for S. aureus colonization.

RESULTS

We found that 42% (95% CI 32-52) of patients were S. aureus colonized in >1 body site. Extranasal colonization was found among 32% (95% CI 23-41). There were trends suggestive of an association between S. aureus colonization and younger age (OR 0.97, 95% CI 0.94-1.001, p = 0.06) and not having been hospitalized in the previous 12 months (OR 0.44, 95% CI 0.19-1.06, p = 0.14).

CONCLUSION

Extranasal S. aureus colonization is common among maintenance hemodialysis patients with a prevalence of approximately one third. Future S. aureus decolonization efforts may need to consider not just nasal decolonization but also decolonization of the skin and oropharynx.

Blood stream infection in patients undergoing systematic off-pump coronary artery bypass: incidence, risk factors, outcome, and associated pathogens

BACKGROUND

Blood stream infection (BSI) is a major cause of mortality and morbidity for patients undergoing cardiac surgery. However, information is lacking about patients undergoing off-pump coronary artery bypass (OPCAB). The purpose of this study was to assess the incidence, risk factors, outcome and associated pathogens of BSI after OPCAB.

METHODS

One thousand ten consecutive patients undergoing OPCAB between 2001 and 2012 were included in a retrospective case-control study. A propensity-matched control was used for risk factor analysis.

RESULTS

Of the 1,010 patients, 26 patients (2.6%) had 32 episodes of BSI after surgery, which occurred at a median of 14 d after surgery. Gram-negative bacilli and gram-positive cocci were distributed equally. Methicillin-resistant Staphylococcus aureus was the pathogen identified most frequently, and the most common source of infection was a surgical site. The hospital mortality rate was 54%. By univariable analysis, diabetes mellitus, pre-operative renal impairment, pre-operative low hemoglobin, pre-operative endotracheal intubation, dialysis before or after surgery, cardiogenic shock, left ventricular ejection fraction of less than 40%, non-elective surgery, low number of distal anastomoses, atrial fibrillation after surgery, and re-operation for bleeding were significant risk factors. By multivariable analysis, the independent risk factors were left ventricular ejection fraction of less than 40%, low number of distal anastomoses, atrial fibrillation after surgery, and dialysis after surgery.

CONCLUSIONS

Blood stream infections remained a common complication after OPCAB, and the mortality was high. Gram-negative bacilli and gram-positive cocci were distributed equally. Methicillin-resistant S. aureus was the pathogen identified most frequently. Preventive tactics should target likely pathogens and high-risk patients undergoing OPCAB.

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.

Implementation of a novel in vitro model of infection of reconstituted human epithelium for expression of virulence genes in methicillin-resistant Staphylococcus aureus strains isolated from catheter-related infections in Mexico

Background

Methicillin-resistant Staphylococcus aureus (MRSA) are clinically relevant pathogens that cause severe catheter-related nosocomial infections driven by several virulence factors.

Methods

We implemented a novel model of infection in vitro of reconstituted human epithelium (RHE) to analyze the expression patterns of virulence genes in 21 MRSA strains isolated from catheter-related infections in Mexican patients undergoing haemodialysis. We also determined the phenotypic and genotypic co-occurrence of antibiotic- and disinfectant-resistance traits in the S. aureus strains, which were also analysed by pulsed-field-gel electrophoresis (PFGE).

Results

In this study, MRSA strains isolated from haemodialysis catheter-related infections expressed virulence markers that mediate adhesion to, and invasion of, RHE. The most frequent pattern of expression (present in 47.6% of the strains) was as follows: fnbA, fnbB, spa, clfA, clfB, cna, bbp, ebps, eap, sdrC, sdrD, sdrE, efb, icaA, and agr. Seventy-one percent of the strains harboured the antibiotic- and disinfectant-resistance genes ermA, ermB, tet(M), tet(K), blaZ, qacA, qacB, and qacC. PFGE of the isolated MRSA revealed three identical strains and two pairs of identical strains. The strains with identical PFGE patterns showed the same phenotypes and genotypes, including the same spa type (t895), suggesting hospital personnel manipulating the haemodialysis equipment could be the source of catheter contamination.

Conclusion

These findings help define the prevalence of MRSA virulence factors in catheter-related infections. Some of the products of the expressed genes that we detected in this work may serve as potential antigens for inclusion in a vaccine for the prevention of MRSA-catheter-related infections.

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.

Persistent nasal methicillin-resistant staphylococcus aureus carriage in hemodialysis outpatients: a predictor of worse outcome

Background

Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) is a well defined risk factor for subsequent bacteremia and death in various groups of patients, but its impact on outcome in patients receiving long-term hemodialysis (HD) is under debate.

Methods

This prospective interventional cohort study (performed 2004 to 2010) enrolled 289 HD outpatients of an urban dialysis-unit. Nasal swab cultures for MRSA were performed in all patients upon first admission, at transfer from another dialysis facility or readmission after hospitalisation. Nasal MRSA carriers were treated in a separate ward and received mupirocin nasal ointment. Concomitant extra-nasal MRSA colonization was treated with 0.2% chlorhexidine mouth rinse (throat) or octenidine dihydrochloride containing antiseptic soaps and 2% chlorhexidine body washes (skin). Clinical data and outcome of carriers and noncarriers were systematically analyzed.

Results

The screening approach identified 34 nasal MRSA carriers (11.7%). Extra-nasal MRSA colonization was observed in 11/34 (32%) nasal MRSA carriers. History of malignancy and an increased Charlson Comorbidity Index were significant predictors for nasal MRSA carriers, whereas traditional risk factors for MRSA colonization or markers of inflammation or malnutrition were not able to discriminate. Kaplan-Meier analysis demonstrated significant survival differences between MRSA carriers and noncarriers. Mupirocin ointment persistently eliminated nasal MRSA colonization in 26/34 (73.5%) patients. Persistent nasal MRSA carriers with failure of this eradication approach had an extremely poor prognosis with an all-cause mortality rate >85%.

Conclusions

Nasal MRSA carriage with failure of mupirocin decolonization was associated with increased mortality despite a lack of overt clinical signs of infection. Further studies are needed to demonstrate whether nasal MRSA colonization represents a novel predictor of worse outcome or just another surrogate marker of the burden of comorbid diseases leading to fatal outcome in HD patients.

Catheter-related infections in chronic hemodialysis: a clinical and economic perspective

PURPOSE

Central venous catheters emerged as a major risk factor for infectious complications in hemodialysis (HD) patients. We aimed to assess the incidence of bacteremia in catheter-dependent HD patients and to characterize its clinical and economic impact.

METHODS

We retrospectively collected clinical data and healthcare costs from 15 months for 75 admitted catheter-dependent HD patients, to document the type of bacteremia (complicated or not), pathogen and inflammation.

RESULTS

Bacteremia (97 % with Staphylococcus aureus, 33 % methicillin-resistant) was present in 51 % patients, with an overall infections incidence of 5.79 per 1,000 catheter-days. Metastatic complications occurred in 21 % of bacteremic patients and were associated with higher mortality (38 vs. 4 %; p = 0.001). Although, in patients starting dialysis on catheter (41 %) as compared to those using catheter as bridge angioaccess, inflammation (higher C-reactive protein; p = 0.006) and anemia (lower Hb; p = 0.008) were more pronounced, bacteremia occurred in a lower proportion (32 vs. 64 %, p = 0.007). The total medical costs were 47 % higher in patients with complicated bacteremia than in those without bacteremia (p = 0.008) and 45 % higher in patients starting HD on catheter than in those using catheter as bridge angioaccess (p = 0.002).

CONCLUSIONS

Despite the limitations resulting from retrospective cross-sectional single-center design, our study suggests that patients already on HD who required catheters as bridge angioaccess were more prone to bacteremia. This highlights the importance of close angioaccess monitoring to avoid unnecessary catheter usage. A similar increase in costs when initiating dialysis on catheter as in case of complicated bacteremia strongly supports the initial placement of a native arteriovenous fistula.

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.

Comparison between patients under hemodialysis with community-onset bacteremia caused by community-associated and healthcare-associated methicillin-resistant Staphylococcus aureus strains

BACKGROUND/PURPOSE(S)

Patients receiving hemodialysis infected with methicillin-resistant Staphylococcus aureus (MRSA) have been considered to have healthcare-associated (HA) infections, but strains with community-associated (CA) characteristics have also been identified in this population. The authors compared infections of the two strains among patients with end-stage renal disease.

METHODS

From January 2004 to December 2008 the authors analyzed the demographic and microbiologic data of 57 patients with community-onset (defined as a positive culture obtained ≤ 48 hours after admission) MRSA bacteremia and end-stage renal disease at a 2900-bed tertiary medical center. MRSA isolate with staphylococcal cassette chromosome mec (SCCmec) type II/III was classified as HA strains, and SCCmec type IV/V as CA strains.

RESULTS

Forty-seven patients (82%) had HA-MRSA strains and 10 patients (18%) had CA-MRSA strains. The major clones of HA-MRSA were sequence type (ST) 5 with SCCmec type II and staphylococcal protein A (spa) t002 as well as ST239 carrying SCCmec type III and spa t037. The CA-MRSA strains were predominantly ST59, more susceptible to non-β-lactam antimicrobial agents, and had a higher percentage of carrying the Panton-Valentine leukocidin gene in comparision with the HA-MRSA strains. Patients infected with HA-MRSA isolates had a higher overall mortality (57.4%, p = 0.012). In multivariate analysis, male patients were more likely to be infected with HA-MRSA isolates than CA-MRSA strains (p = 0.037), and a history of receiving urinary catheterization within 1 year prior to bacteremia onset (p = 0.047) is an independent risk factor to acquiring HA-MRSA strains.

CONCLUSION

Patients undergoing dialysis and infected with HA-MRSA strains had higher mortality rates and were more commonly associated with urinary catheterization within 1 year before bacteremia.

The epidemiology, treatment, and prevention of transmission of methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as an important cause of health care-associated infections for several decades and has more recently emerged as a common cause of infection in persons without typical health care-associated risk factors. It is important for health care providers to have an understanding of the factors associated with MRSA acquisition and infection as well as the interventions that may reduce the risk of MRSA in health care and community settings.

Risk factors for nasal carriage of methicillin-resistant Staphylococcus aureus among patients with end-stage renal disease in Taiwan

BACKGROUND/PURPOSE

Patients with end-stage renal disease (ESRD) are at particular risk for methicillin-resistant Staphylococcus aureus (MRSA) infections, especially via nasal colonization of MRSA. Surveillance cultures are recommended to identify patients colonized by MRSA.

METHODS

Clinical data and screening cultures of S. aureus from the anterior nares of 541 patients on long-term dialysis in the hospitals were performed in March 2007. The follow-up survey was conducted 1 year later.

RESULTS

A total of 32 (5.9%) of the 541 patients were positive nasal cultures for MRSA, while 89 (16.5%) were positive for methicillin-susceptible S. aureus (MSSA). In a multivariate analysis, risk factors for ESRD patients with MRSA colonization included congestive heart failure, nursing home admission, and nasogastric tube feeding in the last 3 months. Follow-up of the 32 MRSA colonized patients showed that one (3.1%) died due to MSSA and three (9.3%) died due from MRSA infection.

CONCLUSIONS

We found that patients with ESRD and MRSA nasal colonization were associated with a history of congestive heart failure, nursing home admission, and nasogastric tube feeding in the last 3 months.

Clinical and molecular epidemiology of methicillin-resistant Staphylococcus aureus among patients in an ambulatory hemodialysis center

OBJECTIVE

To describe the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) carriage and transmission in an ambulatory hemodialysis population.

DESIGN

Prospective cohort study.

SETTING

Outpatient hemodialysis facility affiliated with a large academic medical center.

PARTICIPANTS

Of the 170 facility patients, 103 (61%) participated in the study.

METHODS

Swab specimens of the nares, axillae, and vascular access site were collected from participants weekly for 3 weeks and then monthly for 5 months. Demographic and clinical data were collected monthly for 12 months. Molecular analysis of MRSA isolates was performed.

RESULTS

The baseline MRSA carriage prevalence was 12%. Factors associated with MRSA carriage included a history of MRSA; failed renal transplantation; hospital admission within 6 months; and receipt of a first-generation cephalosporin, cefepime, or vancomycin. Six subjects acquired MRSA after enrollment (incidence, 1.2 per 100 patient-months at-risk; overall prevalence, 18%). Molecular analysis suggested that transmission occurred within the facility. The incidence of MRSA infection among carriers was 1.76 per 100 patient-months. Community-associated strains (ie, USA300) were isolated from 28% of carriers and at least 25% of infections.

CONCLUSIONS

The prevalence of MRSA carriage and the incidence of infection among carriers were high among ambulatory hemodialysis patients, and community-associated MRSA was responsible for a large portion of the MRSA burden. A relatively high rate of MRSA acquisition was observed, with indirect evidence of intrafacility transmission. Additional studies are needed to confirm these findings and to identify effective and feasible methods to prevent MRSA transmission and infection among hemodialysis patients.

The challenge of methicillin-resistant Staphylococcus aureus prevention in hemodialysis therapy

Methicillin-resistant Staphylococcus aureus (MRSA) infections have challenged care process and resource utilization in the acute hospital care setting for nearly 30 years. These infections have become important causes of morbidity, mortality, and a source of concern in the primary and emergency care context over the past decade. As individuals receiving recurrent therapy with features of both ambulatory care and acute care, hemodialysis patients are exposed to numerous opportunities for MRSA acquisition. Surprisingly, high prevalence rates for MRSA colonization have been demonstrated for both hemodialysis patients and their care providers. The necessity of vascular access and the persistent high prevalence of endovascular catheter use among patients repeatedly exposed to healthcare settings provide the perfect milieu for the troubling rates of MRSA infection, particularly bloodstream infections, in outpatient dialysis care. Dialysis industry shifts, including increased requirements for compliance and reporting in other areas of dialysis care, tax resources for infection prevention processes. Multifaceted strategies that include reassessment of vascular access care, attention to the interruption of MRSA transmission dynamics, and emphasis on organizational learning processes are needed to accomplish a meaningful reduction in the morbidity, mortality, and cost associated with MRSA infections in dialysis care.

Attitudes toward patients with multidrug-resistant bacteria: scale development and psychometric evaluation

There is a need for validated assessment tools for measuring attitudes towards patients with multid-rug-resistant bacteria. Such an assessment tool was developed and psychometrically evaluated in the present study. A literature review and discussions with experts and key informants were used to develop the questionnaire. To ensure item adequacy and interpretability, face validity and pre-tests were performed. Item validity, content validity and internal consistency reliability were evaluated in a non-random sample of 329 hemodialysis nurses. The psychometric properties were satisfactory, indicating good item validity. The content validity revealed three appropriate factors with good internal consistency reliability. The haemodialysis nurses′ knowledge about multidrug-resistant bacteria was not sufficient, and their intentional behaviour was unsatisfactory with respect to infection control precautions. The multidrug-resistant bacteria Attitude Questionnaire would be a valuable tool, in nursing practice and nursing education, in promoting quality improvements in patient safety with regard to healthcare associated infections.

The economic value of screening haemodialysis patients for methicillin-resistant Staphylococcus aureus in the USA

Methicillin-resistant Staphylococcus aureus (MRSA) can cause severe infections in patients undergoing haemodialysis. Routine periodic testing of haemodialysis patients and attempting to decolonize those who test positive may be a strategy to prevent MRSA infections. The economic value of such a strategy has not yet been estimated. We constructed a Markov computer simulation model to evaluate the economic value of employing routine testing (agar-based or PCR) at different MRSA prevalence, spontaneous clearance, costs of decolonization and decolonization success rates, performed every 3, 6 or 12 months. The model showed periodic MRSA surveillance with either test to be cost-effective (incremental cost-effectiveness ratio ≤$50 000/quality-adjusted life-year) for all conditions tested. Agar surveillance was dominant (i.e. less costly and more effective) at an MRSA prevalence ≥10% and a decolonization success rate ≥25% for all decolonization treatment costs tested with no spontaneous clearance. PCR surveillance was dominant when the MRSA prevalence was ≥20% and decolonization success rate was ≥75% with no spontaneous clearance. Routine periodic testing and decolonization of haemodialysis patients for MRSA may be a cost-effective strategy over a wide range of MRSA prevalences, decolonization success rates, and testing intervals.

Prevalence, persistence, and microbiology of Staphylococcus aureus nasal carriage among hemodialysis outpatients at a major New York Hospital

The study aimed to determine the natural history of Staphylococcus aureus nasal colonization in hemodialysis outpatients. Surveillance cultures were taken from patients presenting for hemodialysis or routine care to identify S. aureus nasal carriers. A prospective cohort study was performed to identify risks for persistent colonization. Detailed microbiologic and molecular studies of colonizing isolates were performed. Only 23/145 (15.9%) dialysis patients were persistently colonized, and only HIV-positive status was associated with persistence (P = 0.05). Prior hospitalization was the only risk factor for methicillin-resistant S. aureus carriage (OR 2.5, P = 0.03). In isolates from patients with ≤ 42 days of vancomycin exposure, vancomycin minimum bactericidal concentrations (MBCs) increased with duration of exposure. Among dialysis patients, S. aureus colonization was limited and transient; only HIV status was associated with persistence. Nevertheless, duration of vancomycin exposure was associated with increasing vancomycin MBCs. Vancomycin exposure in S. aureus carriers may be involved in increasing resistance.

Should healthcare workers be screened routinely for meticillin-resistant Staphylococcus aureus? A review of the evidence

Meticillin-resistant Staphylococcus aureus (MRSA) is considered endemic in the UK National Health Service (NHS), and routine MRSA screening of hospital inpatients has recently been introduced in both Scotland and England. The UK National Screening Committee states that public pressure for widening the eligibility criteria of a proposed screening programme should be anticipated and any related decisions scientifically justifiable. A literature review was conducted to examine whether MRSA screening in Scotland should be expanded to include the routine screening of healthcare workers (HCWs). There are no published prevalence studies reporting the overall MRSA carriage rate in HCWs in NHS hospitals. Estimates of HCW carriage from the worldwide literature vary widely depending on the country, hospital specialty and setting (endemic, non-endemic or outbreak). Recent studies conducted in endemic hospital settings report non-outbreak carriage rates of 0-15%. The role of HCW carriage in the transmission of MRSA is not well understood. Persistent carriage could act as a reservoir for infection and HCWs have been implicated as the source in a number of published outbreak reports. There are no published controlled trials examining the impact of routine HCW screening as an intervention in the prevention and control of MRSA infections in the endemic hospital setting. Most of the evidence for HCW screening comes from outbreak reports where the outbreak was brought to an end following the introduction of staff screening as part of a suite of infection control measures. Further research is required before a recommendation could be made to introduce routine MRSA screening of HCWs in the NHS in Scotland.

Quantitative analysis and molecular fingerprinting of methicillin-resistant Staphylococcus aureus nasal colonization in different patient populations: a prospective, multicenter study

OBJECTIVES

To better understand the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection in different patient populations, to perform quantitative analysis of MRSA in nasal cultures, and to characterize strains using molecular fingerprinting.

DESIGN

Prospective, multicenter study.

SETTING

Eleven different inpatient and outpatient healthcare facilities.

PARTICIPANTS

MRSA-positive inpatients identified in an active surveillance program; inpatients and outpatients receiving hemodialysis; inpatients and outpatients with human immunodeficiency virus (HIV) infection; patients requiring cardiac surgery; and elderly patients requiring long-term care. METHODS. Nasal swab samples were obtained from January 23, 2006, through July 27, 2007; MRSA strains were quantified and characterized by molecular fingerprinting.

RESULTS

A total of 444 nares swab specimens yielded MRSA (geometric mean quantity, 794 CFU per swab; range, 3-15,000,000 CFU per swab). MRSA prevalence was 20% for elderly residents of long-term care facilities (25 of 125 residents), 16% for HIV-infected outpatients (78 of 494 outpatients), 15% for outpatients receiving hemodialysis (31 of 208 outpatients), 14% for inpatients receiving hemodialysis (86 of 623 inpatients), 3% for HIV-infected inpatients (5 of 161 inpatients), and 3% for inpatients requiring cardiac surgery (6 of 199 inpatients). The highest geometric mean quantity of MRSA was for inpatients requiring cardiac surgery (11,500 CFU per swab). An association was found between HIV infection and colonization with the USA300 or USA500 strain of MRSA (P < or = .001). The Brazilian clone was found for the first time in the United States. Pulsed-field gel electrophoresis patterns for 11 isolates were not compatible with known USA types or clones.

CONCLUSION

Nasal swab specimens positive for MRSA had a geometric mean quantity of 794 CFU per swab, with great diversity in the quantity of MRSA at this anatomic site. Outpatient populations at high risk for MRSA carriage were elderly residents of long-term care facilities, HIV-infected outpatients, and outpatients receiving hemodialysis.

Prevention and control of health care-associated infections through improved hand hygiene

Determined actions are required to address the burden due to health care-associated infections worldwide and improve patient safety. Improving hand hygiene among health care workers is an essential intervention to achieve these goals. The World Health Organization (WHO) First Global Patient Safety Challenge, Clean Care is Safer Care, pledged to tackle the problem of health care-associated infection at its launch in 2005 and has elaborated a comprehensive set of guidelines for use in both developed and developing countries worldwide. The final version of the WHO Guidelines on Hand Hygiene in Health Care was issued in March 2009 and includes recommendations on indications, techniques, and products for hand hygiene. In this review, we discuss the role of hands in the transmission of health care-associated infection, the benefits of improved compliance with hand hygiene, and the recommendations, implementation strategies and tools recommended by WHO. We also stress the need for action to increase the pace with which these recommendations are implemented in facilities across India.

Prevalence of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus carriage in three populations

BACKGROUND

A higher prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization is reported in healthcare workers compared with nonhealthcare workers.

HYPOTHESIS

The prevalence of MRSA colonization differed in people and pets in households with healthcare workers as compared with households without healthcare workers.

SUBJECTS

A person and 1 dog or cat from 586 households defined as either a nonhealthcare (n = 213), veterinary healthcare (n = 211), or human healthcare (n = 162) worker household.

METHODS

Prospective cross-sectional study. Samples from humans and pets were cultured in vitro. Staphylococcus aureus was identified as methicillin sensitive (MSSA) or MRSA with mecA polymerase chain reaction. Pulsed-field gel electrophoresis and spa-typing were used to characterize relatedness of S. aureus and MRSA and assign USA types.

RESULTS

The prevalence of MSSA and MRSA in humans was 21.5% (126/586) and 5.63% (33/586), respectively, and 7.85% (46/586) and 3.41% (20/586), respectively, in pets. There were no differences in prevalences of either MSSA or MRSA between household types. The proportion of MRSA among all S. aureus isolates in humans and pets was 20.8% (33/159) and 30.3% (20/66), respectively. In < 1.0% (4/586) of households, the same strain of MRSA was found in both a person and a pet.

CONCLUSIONS AND CLINICAL IMPORTANCE

There were no differences in the prevalences of MSSA or MRSA between healthcare worker and nonhealthcare worker households. Pets and people colonized with S. aureus were as likely to be colonized with MRSA. Colonization of a person and their pet with the same strain of MRSA was rare.

Community-associated methicillin-resistant Staphylococcus aureus: epidemiology and clinical consequences of an emerging epidemic

Staphylococcus aureus is an important cause of skin and soft-tissue infections (SSTIs), endovascular infections, pneumonia, septic arthritis, endocarditis, osteomyelitis, foreign-body infections, and sepsis. Methicillin-resistant S. aureus (MRSA) isolates were once confined largely to hospitals, other health care environments, and patients frequenting these facilities. Since the mid-1990s, however, there has been an explosion in the number of MRSA infections reported in populations lacking risk factors for exposure to the health care system. This increase in the incidence of MRSA infection has been associated with the recognition of new MRSA clones known as community-associated MRSA (CA-MRSA). CA-MRSA strains differ from the older, health care-associated MRSA strains; they infect a different group of patients, they cause different clinical syndromes, they differ in antimicrobial susceptibility patterns, they spread rapidly among healthy people in the community, and they frequently cause infections in health care environments as well. This review details what is known about the epidemiology of CA-MRSA strains and the clinical spectrum of infectious syndromes associated with them that ranges from a commensal state to severe, overwhelming infection. It also addresses the therapy of these infections and strategies for their prevention.

A veterinary perspective on methicillin-resistant staphylococci

OBJECTIVE

To familiarize the reader with the epidemiology, diagnosis, and infectious and zoonotic potential of methicillin-resistant staphylococci.

DATA SOURCES

Original research publications, scientific reviews and abstracts, case reports, and conference proceedings.

HUMAN DATA SYNTHESIS

Staphylococcus aureus is a common human commensal organism; acquisition of genes encoding an altered penicillin-binding protein confers resistance to beta-lactam antimicrobial drugs. Methicillin-resistant S. aureus (MRSA) are often resistant to non-beta-lactam antimicrobial drugs as well. Originally described as an important cause of nosocomial infection, MRSA colonization and infection are now often identified in humans outside healthcare settings. Like other S. aureus, MRSA may be present without clinical illness. However, when they do cause infection the consequences can be extremely serious.

VETERINARY DATA SYNTHESIS

The major domestic animal species, including pets and livestock, may become contaminated, colonized, or infected with methicillin-resistant staphylococci, including MRSA. Dogs and cats are more likely to be colonized/infected with Staphylococcus pseudintermedius than S. aureus, but this pathogen can acquire genes encoding methicillin resistance (ie, MRSP). Diagnosis of MRSA or MRSP has implications not only for treatment of infected animals, but for potential zoonotic transmission.

CONCLUSIONS

MRSA infection is an important cause of morbidity and mortality in humans. Animals may be contaminated, colonized, or infected with MRSA, with implications for the animal's health and as a potential reservoir for human infection. Staphylococci other than S. aureus may also acquire genes for methicillin resistance, and these species can also result in animal and occasionally human morbidity or mortality.