The economic impact of methicillin-resistant Staphylococcus aureus in Canadian hospitals

Effectiveness of methicillin-resistant Staphylococcus aureus surveillance among exposed roommates in community hospitals: Conventional culture versus direct PCR

BACKGROUND

Roommates of unrecognized nosocomial methicillin-resistant Staphylococcus aureus (MRSA) cases are at a higher acquisition risk; however, optimal surveillance strategies are unknown.

METHODS

Using simulation, we analyzed surveillance testing and isolation strategies for MRSA among exposed hospital roommates. We compared isolating exposed roommates until conventional culture testing on day 6 and a nasal polymerase chain reaction test on day 3 (PCR3) with/without day 0 culture testing (Cult0). The model represents MRSA transmission in medium-sized hospitals using data and recommends best practices from the literature and Ontario community hospitals.

RESULTS

Cult0 + PCR3 incurred a slightly lower number of MRSA colonizations and 38.9% lower annual cost in the base case compared to Cult0 + culture testing on day 6 because the reduced isolation cost compensated for the increased testing cost. The reduction in MRSA colonizations was due to a 54.5% drop in MRSA transmissions during isolation as PCR3 reduced the exposure of MRSA-free roommates to new MRSA carriers. Removing the day 0 culture test from Cult0 + PCR3 increased total cost, the number of MRSA colonization, and missed cases by $1,631, 4.3%, and 50.9%, respectively. Improvements were higher under aggressive MRSA transmission scenarios.

DISCUSSION AND CONCLUSIONS

Adopting direct nasal polymerase chain reaction testing for determining post-exposure MRSA status reduces transmission risk and costs. Day 0 culture would still be beneficial.

The Application of Nucleic Acids and Nucleic Acid Materials in Antimicrobial Research

Due to the misuse of antibiotics, multiple drug-resistant pathogenic bacteria have increasingly emerged. This has increased the difficulty of treatment as these bacteria directly affect public health by diminishing the potency of existing antibiotics. Developing alternative therapeutic strategies is the urgent need to reduce the mortality and morbidity related to drug-resistant bacterial infections. In the past 10 to 20 years, nanomedicines have been widely studied and applied as an antibacterial agent. They have become a novel tool for fighting resistant bacteria. The most common innovative substances, metal and metal oxide nanoparticles (NPs), have been widely reported. Until recently, DNA nanostructures were used alone or functionalized with specific DNA sequences by many scholars for antimicrobial purposes which were alternatively selected as therapy for severe bacterial infections. These are a potential candidate for treatments and have a considerable role in killing antibiotic-resistant bacteria. This review involves the dimensions of multidrug resistance and the mechanism of bacteria developing drug resistance. The importance of this article is that we summarized the current study of nano-materials based on nucleic acids in antimicrobial use. Meanwhile, the current progress and the present obstacles for their antibacterial and therapeutic use and special function of stem cells in this field are also discussed.

An agent-based model to simulate the transmission of vancomycin-resistant enterococci according different prevention and control measures

OBJECTIVE

Despite the existence of various levels of infection prevention and control (IPC) measures aimed at limiting the transmission of vancomycin-resistant enterococci (VRE) in hospitals, these measures are sometimes difficult to implement. Using an agent-based model (ABM), we simulated the transmission of VRE within and between 3 care units according to different IPC measures.

METHODS

The ABM was modelled on short-stay medical wards, represented by 2 conventional care units and 1 intensive care unit. The scenarios consisted of the simulation of various compliance rates of caregivers with regard to hand hygiene (HH) in different contexts of IPC measures: (1) standard precautions for all patients, (2) additional contact precautions for VRE-carrier patients, (3) geographical cohorting of carrier patients, and (4) creation of an isolation unit with dedicated staff.

RESULTS

With <50% HH compliance, the dissemination of VRE was not adequately controlled. With 80% compliance for all patients (ie, standard precautions scenario), there were no secondary VRE cases in 50% of the simulations, which represented the best scenario. A more realistic rate, 60% HH compliance for all patients, revealed interesting results. Implementing an isolation unit was effective only if the level of HH compliance was low. Patient cohorting was less effective.

CONCLUSIONS

The present ABM showed that while contact precautions, geographic cohorting, and an isolation unit may represent good complements to standard precautions, they may theoretically not be necessary if HH is followed at a high level of compliance.

Re-sensitizing Ampicillin and Kanamycin-Resistant E. coli and S. aureus Using Synergistic Metal Micronutrients-Antibiotic Combinations

Due to the recent emergence of multi-drug resistant strains, the development of novel antimicrobial agents has become a critical issue. The use of micronutrient transition metals is a promising approach to overcome this problem since these compounds exhibit significant toxicity at low concentrations in prokaryotic cells. In this work, we demonstrate that at concentrations lower than their minimal inhibitory concentrations and in combination with different antibiotics, it is possible to mitigate the barriers to employ metallic micronutrients as therapeutic agents. Here, we show that when administered as a combinatorial treatment, Cu²⁺, Zn²⁺, Co²⁺, Cd²⁺, and Ni²⁺ increase susceptibility of Escherichia coli and Staphylococcus aureus to ampicillin and kanamycin. Furthermore, ampicillin-resistant E. coli is re-sensitized to ampicillin when the ampicillin is administered in combination with Cu²⁺, Cd²⁺, or Ni². Similarly, Cu²⁺, Zn²⁺, or Cd²⁺ re-sensitize kanamycin-resistant E. coli and S. aureus to kanamycin when administered in a combinatorial treatment with those transition metals. Here, we demonstrate that for both susceptible and resistant bacteria, transition-metal micronutrients, and antibiotics interact synergistically in combinatorial treatments and exhibit increased effects when compared to the treatment with the antibiotic alone. Moreover, in vitro and in vivo assays, using a murine topical infection model, showed no toxicological effects of either treatment at the administered concentrations. Lastly, we show that combinatorial treatments can clear a murine topical infection caused by an antibiotic-resistant strain. Altogether, these results suggest that antibiotic-metallic micronutrient combinatorial treatments will play an important role in future developments of antimicrobial agents and treatments against infections caused by both susceptible and resistant strains.

Reduction of Health Care-Associated Infections (HAIs) with Antimicrobial Inorganic Nanoparticles Incorporated in Medical Textiles: An Economic Assessment

Health care-associated infections (HAIs) affect millions of patients annually with up to 80,000 affected in Europe on any given day. This represents a significant societal and economic burden. Staff training, hand hygiene, patient identification and isolation and controlled antibiotic use are some of the standard ways to reduce HAI incidence but this is time consuming and subject and subject to rigorous implementation. In addition, the lack of antimicrobial activity of some disinfectants against healthcare-associated pathogens may also affect the efficacy of disinfection practices. Textiles are an attractive substrate for pathogens because of contact with the human body with the attendant warmth and moisture. Textiles and surfaces coated with engineered nanomaterials (ENMs) have shown considerable promise in reducing the microbial burden on those surfaces. Studies have also shown that this antimicrobial affect can reduce the incidence of HAIs. For all of the promising research, there has been an absence of study on the economic effectiveness of ENM coated materials in a healthcare setting. This article examines the relative economic efficacy of ENM coated materials against an antiseptic approach. The goal is to establish the economic efficacy of the widespread usage of ENM coated materials in a healthcare setting. In the absence of detailed and segregated costs, benefits and control variables over at least cross sectional data or time series, an aggregated approach is warranted. This approach, while relying on some supposition allows for a comparison with similar data regarding standard treatment to reduce HAIs and provides a reasonable economic comparison. We find that while, relative to antiseptics, ENM coated textiles represent a significant clinical advantage, they can also offer considerable cost savings.

Systematic review of patient-oriented interventions to reduce unnecessary use of antibiotics for upper respiratory tract infections

BACKGROUND

Antibiotics are prescribed frequently for upper respiratory tract infections (URTIs) even though most URTIs do not require antibiotics. This over-prescription contributes to antibiotic resistance which is a major health problem globally. As physicians' prescribing behaviour is influenced by patients' expectations, there may be some opportunities to reduce antibiotic prescribing using patient-oriented interventions. We aimed to identify these interventions and to understand which ones are more effective in reducing unnecessary use of antibiotics for URTIs.

METHODS

We conducted a systematic review by searching the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OVID), EMBASE (OVID), CINAHL, and the Web of Science. We included English language randomized controlled trials (RCTs), quasi-RCTs, controlled before and after studies, and interrupted time series (ITS) studies. Two authors screened the abstract/titles and full texts, extracted data, and assessed study risk of bias. Where pooling was appropriate, a meta-analysis was performed by using a random-effects model. Where pooling of the data was not possible, a narrative synthesis of results was conducted.

RESULTS

We included 13 studies (one ITS, one cluster RCTs, and eleven RCTs). All interventions could be classified into two major categories: delayed prescriptions (seven studies) and patient/public information and education interventions (six studies). Our meta-analysis of delayed prescription studies observed significant reductions in the use of antibiotics for URTIs (OR = 0.09, CI 0.03 to 0.23; six studies). A subgroup analysis showed that prescriptions that were given at a later time and prescriptions that were given at the index consultation had similar effects. The studies in the patient/public information and education group varied according to their methods of delivery. Since only one or two studies were included for each method, we could not make a definite conclusion on their effectiveness. In general, booklets or pamphlets demonstrated promising effects on antibiotic prescription, if discussed by a practitioner.

CONCLUSIONS

Patient-oriented interventions (especially delayed prescriptions) may be effective in reducing antibiotic prescription for URTIs. Further research is needed to investigate the costs and feasibility of implementing these interventions as part of routine clinical practice.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016048007.

Comparing methods to estimate incremental inpatient costs and length of stay due to methicillin-resistant Staphylococcus aureus in Alberta, Canada

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is an opportunistic bacterial organism resistant to first line antibiotics. Acquisition of MRSA is often classified as either healthcare-associated or community-acquired. It has been shown that both healthcare-associated and community-acquired infections contribute to the spread of MRSA within healthcare facilities. The objective of this study was to estimate the incremental inpatient cost and length of stay for individuals colonized or infected with MRSA. Common analytical methods were compared to ensure the quality of the estimate generated. This study was performed at Alberta Ministry of Health (Edmonton, Alberta), with access to clinical MRSA data collected at two Edmonton hospitals, and ministerial administrative data holdings.

Methods

A retrospective cohort study of patients with MRSA was identified using a provincial infection prevention and control database. A coarsened exact matching algorithm, and two regression models (semilogarithmic ordinary least squares model and log linked generalized linear model) were evaluated. A MRSA-free cohort from the same facilities and care units was identified for the matched method; all records were used for the regression models. Records span from January 1, 2011 to December 31, 2015, for individuals 18 or older at discharge.

Results

Of the models evaluated, the generalized linear model was found to perform the best. Based on this model, the incremental inpatient costs associated with hospital-acquired cases were the most costly at $31,686 (14,169 – 60,158) and $47,016 (23,125 – 86,332) for colonization and infection, respectively. Community-acquired MRSA cases also represent a significant burden, with incremental inpatient costs of $7397 (2924 – 13,180) and $14,847 (8445 – 23,207) for colonization and infection, respectively. All costs are adjusted to 2016 Canadian dollars. Incremental length of stay followed a similar pattern, where hospital-acquired infections had the longest incremental stays of 35.2 (16.3–69.5) days and community-acquired colonization had the shortest incremental stays of 3.0 (0.6–6.3) days.

Conclusions

MRSA, and in particular, hospital-acquired MRSA, places a significant but preventable cost burden on the Alberta healthcare system. Estimates of cost and length of stay varied by the method of analysis and source of infection, highlighting the importance of selecting the most appropriate method.

What can we learn by examining variations in the use of urine culture in the management of acute cystitis? A retrospective cohort study with linked administrative data in British Columbia, Canada, 2005-2011

Introduction

Urinary tract infections (UTI) are common community-based bacterial infections. Empiric antibiotic recommendations are guided by local resistance rates. Previous research suggests that cultures are overused for uncomplicated cystitis, but practice patterns have not been described in detail. Variations in culturing have implications for the interpretation of antibiotic resistance rates.

Methods

We used a retrospective cohort study to analyze variations in urine culturing among physicians, controlling for patient and physician characteristics. We identified all outpatient physician visits among adults and children for cystitis in British Columbia between 2005 and 2011 using administrative data and linked these to laboratory data on urine cultures. Using hierarchical generalized linear mixed models we explored variations in urine culture submissions for cystitis (ICD code 595) and the associations with patient and physician characteristics, stratified by patient sex.

Results

Urine cultures were associated with 16% of visits for cystitis among females and 9% among males, and 59% of visits overall were associated with antibiotic treatment. Older patients, patients with a recent antibiotic prescription, and long term care residents were significantly less likely to have a culture associated with a cystitis visit, whether male or female. Female physicians and physicians with 16–35 years’ experience were more likely to culture, while international medical graduates were less likely–particularly for female visits. Notably, there was substantial unexplained variation among physicians after controlling for physician characteristics: we found a 24-fold variation in the odds of culturing a female UTI between physicians who were otherwise similar.

Conclusion

Individual physicians show substantial variation in their propensity to submit cultures for cystitis visits. Reducing such variation and encouraging appropriate levels of culturing would support effective antibiotic use.

In-hospital costs of community-acquired colonization with multidrug-resistant organisms at a German teaching hospital

Background

Antibiotic resistance is a challenge in the management of infectious diseases and can cause substantial cost. Even without the onset of infection, measures must be taken, as patients colonized with multi-drug resistant (MDR) pathogens may transmit the pathogen. We aim to quantify the cost of community-acquired MDR colonizations using routine data from a German teaching hospital.

Methods

All 2006 cases of documented MDR colonization at hospital admission recorded from 2011 to 2014 are matched to 7917 unexposed controls with the same primary diagnosis. Cases with an onset MDR infection are excluded from the analysis. Routine data on costs per case is analysed for three groups of MDR bacteria: Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus (VRE), and multidrug-resistant gram-negative bacteria (MDR-GN). Multivariate analyses are conducted to adjust for potential confounders.

Results

After controlling for main diagnosis group, age, sex, and Charlson Comorbidity Index, MDR colonization is associated with substantial additional costs from the healthcare perspective (€1480.9, 95%CI €1286.4–€1675.5). Heterogeneity between pathogens remains. Colonization with MDR-GN leads to the largest cost increase (€1966.0, 95%CI €1634.6–€2297.4), followed by MRSA with €1651.3 (95%CI €1279.1–€2023.6), and VRE with €879.2 (95%CI €604.1–€1154.2). At the same time, MDR-GN is associated with additional reimbursements of €887.8 (95%CI €722.1–€1053.6), i.e. costs associated with MDR-colonization exceed reimbursement.

Conclusions

Even without the onset of invasive infection, documented MDR-colonization at hospital admission is associated with increased hospital costs, which are not fully covered within the German DRG-based hospital payment system.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3549-0) contains supplementary material, which is available to authorized users.

Situational analysis of antibiotic use and resistance in Ghana: policy and regulation

Background

Antibiotics have played an essential role in decreasing morbidity and mortality from infectious diseases. However, indiscriminate use and unrestricted access is contributing to the emergence of bacterial resistance. This paper reports on a situational analysis of antimicrobial use and resistance in Ghana, with focus on policy and regulation.

Methods

Relevant policy documents, reports, regulations and enactments were reviewed. PubMed and Google search engines were used to extract relevant published papers. Websites of stakeholders such as Ministry of Health (MOH) and its agencies were also reviewed. An interview guide was used to elicit responses from selected officials from these sectors.

Results

Laws and guidelines to control the use of antimicrobials in humans were available but not for animals. There was no National Antimicrobial Policy (NAP). A health practice regulatory law mandates Physicians, Physician Assistants, Midwives and trained Nurses to prescribe antimicrobials. However, antibiotics are widely prescribed and dispensed by unauthorised persons, suggesting weak enforcement of the laws. Antibiotics were also supplied to and from unapproved medicine outlets. The Standard Treatment Guidelines (STG), Essential Medicines List (EML) and the National Health Insurance Scheme Medicines List (NHISML) provide restrictions regarding levels of prescribing of antimicrobials. However, existing guidelines on antibiotic use are mostly not adhered to. The use of Automatic Stop Orders to avoid wastage in the hospitals is also not practiced. Data on use of antibiotics for individuals are not readily available in most facilities. Again, there are no standards or guidelines on veterinary use of antibiotics. Surveillance systems for consumption of antibiotics and resistance monitoring were not in place in most health facilities. However, there is an ongoing national action to create awareness on bacteria resistance, strengthening knowledge through research and surveillance and development of NAP in line with global action plan on antimicrobial resistance.

Conclusion

Absence of national antimicrobial policy, weak regulatory environment and non-adherence to practice standards may have contributed to increased and unregulated access to antimicrobials in Ghana, a catalyst for development and spread of antimicrobial resistance.

Electronic supplementary material

The online version of this article (10.1186/s12889-017-4910-7) contains supplementary material, which is available to authorized users.

Health professionals' knowledge about relative prevalence of hospital-acquired infections in Delta State of Nigeria

INTRODUCTION

Hospital-acquired infections (HAIs) constitute a serious global public health challenge, causing great suffering to many people across the globe at any given time. This study ascertains the knowledge of health professionals on the challenge and their compliance with infection control measures.

METHODS

Validated questionnaires were administered to 660 health professionals and supported with face-to-face interview. Data were analyzed using Statistical Package for Social Sciences (SPSS) version 16.0 (SPSS Inc, USA). Chi-square was used to test association between the independent and the outcome variables. Cut-off point for statistical significance was 5% (p value<0.05).

RESULTS

UTIs (61.4%) followed by Hospital-acquired Pneumonia (55.6%) were known to be the most prevalent HAIs in government hospitals while Staphylococcus aureus (54.4%) was reported the most microbial agent. In private health facilities, Hospital-acquired Pneumonia was known to be the most common (66.1%) while Pseudomonas aeruginosa was the most reported culprit. HAIs were reported to have occurred more in government hospitals and catheterization was the commonest modes of transmission in both health facilities.

CONCLUSION

The prevalence of HAIs in this state was reported to be high. Although health-care professionals have good knowledge of HAIs, active effort is not always made to identify and resolve them. Standardized surveillance of HAIs is urgently needed.

Health Care Workers’ Hand Decontamination Practices

The primary purpose of this quasi-experimental research is to observe health care workers’ compliance with hand-hygiene guidelines during patient care in an intensive care unit in Ireland before (pretest) and after (posttest) implementation of a multifaceted hand-hygiene program. Health care workers’ attitudes, beliefs, and knowledge in relation to compliance with handwashing guidelines were also investigated. A convenience sample of nurses, doctors, physiotherapists, and care assistants ( n = 73 observational participants, n = 62 questionnaire respondents) was used. Data ( N = 314 observations, 62 questionnaires) were analyzed descriptively and cross-tabulated using chi-square (Pearson’s) and Mann-Whitney statistical tests. Results revealed that a significant shift (32%) occurred in health care workers’ compliance with handwashing guidelines (pretest 51%, posttest 83%, p < .001) following the interventional hand-hygiene program. Significant changes were also found in relation to health care workers’ attitudes, beliefs, and knowledge ( p < .05).

Modeling Transmission of Methicillin-ResistantStaphylococcus AureusAmong Patients Admitted to a Hospital

Objective:

To determine the impact of the screening test, nursing workload, handwashing rates, and dependence of handwashing on risk level of patient visit on methicillin-resistantStaphylococcus aureus(MRSA) transmission among hospitalized patients.

Setting:

General medical ward.

Methods:

Monte Carlo simulation was used to model MRSA transmission (median rate per 1,000 patient-days). Visits by healthcare workers (HCWs) to patients were simulated, and MRSA was assumed to be transmitted among patients via HCWs.

Results:

The transmission rate was reduced from 0.89 to 0.56 by the combination of increasing the sensitivity of the screening test from 80% to 99% and being able to report results in 1 day instead of 4 days. Reducing the patient-to-nurse ratio from 4.3 in the day and 6.8 at night to 3.8 and 5.7, respectively, reduced the number of nosocomial infections from 0.89 to 0.85; reducing the ratio to 1 and 1, respectively, further reduced the number of nosocomial infections to 0.32. Increases in handwashing rates by 0%, 10%, and 20% for high-risk visits yielded reductions in nosocomial infections similar to those yielded by increases in handwashing rates for all visits (0.89, 0.36, and 0.24, respectively). Screening all patients for MRSA at admission reduced the transmission rate to 0.81 per 1,000 patient-days from 1.37 if no patients were screened.

Conclusion:

Within the ranges of parameters studied, the most effective strategies for reducing the rate of MRSA transmission were increasing the handwashing rates for visits involving contact with skin or bodily fluid and screening patients for MRSA at admission. (Infect Control Hosp Epidemiol 2005;26:607- 615)

Methicillin-ResistantStaphylococcus AureusCarriage Among Patients After Hospital Discharge

Background and Objective:

At the University Medical Center Utrecht (UMCU), follow-up implies an inventory of risk factors and screening for MRSA colonization among all MRSA-positive patients for at least 6 months. If risk factors or positive cultures persist or re-emerge, longer follow-up is indicated and isolation at readmission. This study investigated how long MRSA-positive patients remained colonized after hospital discharge and which risk factors were important. Furthermore, the results of eradication therapy were evaluated.

Design:

All patients who were positive for MRSA at the UMCU between January 1991 and January 2001 were analyzed regarding carriage state, presence of risk factors for prolonged carriage ofStaphylococcus aureus, and eradication treatment.

Results:

A total of 135 patients were included in the study. The median follow-up time was 1.2 years. Eighteen percent of the patients were dismissed from follow-up 1 year after discharge. Only 5 patients were dismissed after 6 months. Among patients with no risk factors, eradication treatment was effective for 95% within 1 year. Among patients with persistent risk factors, treatment was effective for 89% within 2 years.

Conclusions:

Based on these findings, eradication therapy should be prescribed for all MRSA carriers, independent of the presence of risk factors. MRSA-positive patients should be evaluated for 6 months for the presence of risk factors and MRSA carriage. Screening for risk factors is important because intermittent MRSA carriage was found in a significant number of our patients. Patients with negative MRSA cultures and without risk factors for 12 months can be safely dismissed from follow-up. (Infect Control Hosp Epidemiol 2005;26:629-633)

Duration of Colonization with Methicillin-ResistantStaphylococcus aureusAmong Patients in the Intensive Care Unit: Implications for Intervention

Objectives.

To determine the duration of methicillin-resistantStaphylococcus aureus(MRSA) colonization or infection before entry and during hospitalization in the intensive care unit (ICU) and the characteristics of patients who tested positive for MRSA.

Design.

Prospective observational cohort survey.

Setting.

A combined medical and coronary care ICU with 16 single-bed rooms in a 427-bed tertiary care Veteran Affairs Medical Center

Patients.

A total of 720 ICU patients associated with 845 ICU admissions were followed up for the detection of MRSA from January 13, 2003, to October 12, 2003. MRSA colonization was detected in patients by using active surveillance cultures (ASCs) of nasal swab specimens obtained within 48 hours of ICU entry and 3 times weekly thereafter. The duration of colonization during ICU stay and before ICU entry was calculated after a review of surveillance culture results, clinical culture results, and medical history.

Results.

Ninety-three (11.0%) of 845 ICU admissions involved patients who were colonized with MRSA at the time of ICU entry, and 21 admissions (2.5%) involved patients who acquired MRSA during ICU stay. ASCs were positive for MRSA in 84 (73.6%) of the 114 admissions associated with MRSA positivity and were the sole means of identifying MRSA in 50 cases (43.8%). More than half of the MRSA-associated admissions involved patients who were transferred from hospital wards. The total bed-days of care for 38 admissions involving patients who tested positive for MRSA before ICU entry (1131 days) was nearly 20% higher than the total bed-days of care for all admissions associated with MRSA positivity (970 days). Admissions involving MRSA-positive patients were associated with a longer length of hospitalization before ICU entry (P<.001), longer length of ICU stay (P<.001), longer overall length of hospitalization (P<.001), and greater inpatient mortality than admissions involving MRSA-negative patients (P<.001). A total of 22.8% of all bed-care days were dedicated to MRSA-positive patients in the ICU, and 55 (48.2%) of 114 admissions associated with MRSA positivity involved patients who were colonized for the duration of their ICU stay.

Conclusions.

In our unit, ASCs were an effective means to identify MRSA colonization among patients admitted to the ICU. Unfortunately, the majority of identified patients had long durations of stay in our own hospital before ICU entry, with prolonged MRSA colonization. Enhanced efforts to control MRSA will have to account for the prevalence of MRSA within hospital wards and to direct control efforts at these patients in the future.

Costs and Outcomes Among Hemodialysis-Dependent Patients With Methicillin-Resistant or Methicillin-SusceptibleStaphylococcus aureusBacteremia

Objective:

Comorbid conditions have complicated previous analyses of the consequences of methicillin resistance for costs and outcomes ofStaphylococcus aureusbacteremia. We compared costs and outcomes of methicillin resistance in patients withS. aureusbacteremia and a single chronic condition.

Design, Setting, and Patients:

We conducted a prospective cohort study of hemodialysis-dependent patients with end-stage renal disease andS. aureusbacteremia hospitalized between July 1996 and August 2001. We used propensity scores to reduce bias when comparing patients with methicillin-resistant (MRSA) and methicillin-susceptible (MSSA)S. aureusbacteremia. Outcome measures were resource use, direct medical costs, and clinical outcomes at 12 weeks after initial hospitalization.

Results:

Fifty-four patients (37.8%) had MRSA and 89 patients (62.2%) had MSSA. Compared with patients with MSSA bacteremia, patients with MRSA bacteremia were more likely to have acquired the infection while hospitalized for another condition (27.8% vs 12.4%;P= .02). To attribute all inpatient costs toS. aureusbacteremia, we limited the analysis to 105 patients admitted for suspectedS. aureusbacteremia from a community setting. Adjusted costs were higher for MRSA bacteremia for the initial hospitalization ($21,251 vs $13,978;P= .012) and after 12 weeks ($25,518 vs $17,354;P= .015). At 12 weeks, patients with MRSA bacteremia were more likely to die (adjusted odds ratio, 5.4; 95% confidence interval, 1.5 to 18.7) than were patients with MSSA bacteremia.

Conclusions:

Community-dwelling, hemodialysis-dependent patients hospitalized with MRSA bacteremia face a higher mortality risk, longer hospital stays, and higher inpatient costs than do patients with MSSA bacteremia.

Costs and possible benefits of a two-tier infection control management strategy consisting of active screening for multidrug-resistant organisms and tailored control measures

BACKGROUND

Multidrug-resistant organisms (MDROs) are an economic burden, and infection control (IC) measures are cost- and labour-intensive. A two-tier IC management strategy was developed, including active screening, in order to achieve effective use of limited resources. Briefly, high-risk patients were differentiated from other patients, distinguished according to type of MDRO, and IC measures were implemented accordingly.

AIM

To evaluate costs and benefits of this IC management strategy.

METHODS

The study period comprised 2.5 years. All high-risk patients underwent microbiological screening. Gram-negative bacteria (GNB) were classified as multidrug-resistant (MDR) and extensively drug-resistant (XDR). Expenses consisted of costs for staff, materials, laboratory, increased workload and occupational costs.

FINDINGS

In total, 39,551 patients were screened, accounting for 24.5% of all admissions. Of all screened patients, 7.8% (N=3,104) were MDRO positive; these patients were mainly colonized with vancomycin-resistant enterococci (37.3%), followed by meticillin-resistant Staphylococcus aureus (30.3%) and MDR-GNB (28.3%). The median length of stay (LOS) for all patients was 10 days (interquartile range 3-20); LOS was twice as long in colonized patients (P<0.001). Screening costs totalled 255,093.82€, IC measures cost 97,701.36€, and opportunity costs were 599,225.52€. The savings of this IC management strategy totalled 500,941.84€. Possible transmissions by undetected carriers would have caused additional costs of 613,648.90-4,974,939.26€ (i.e. approximately 600,000-5 million €).

CONCLUSION

Although the costs of a two-tier IC management strategy including active microbiological screening are not trivial, these data indicate that the approach is cost-effective when prevented transmissions are included in the cost estimate.

Genome Analysis of Phage SMSAP5 as Candidate of Biocontrol for Staphylococcus aureus

In this study, we reported the morphogenetic analysis and genome sequence by genomic analysis of the newly isolated staphylococcal phage SMSAP5 from soil of slaughterhouses for cattle. Based on transmission electron microscopy evident morphology, phage SMSAP5 belonged to the Siphoviridae family. Phage SMSAP5 had a double-stranded DNA genome with a length of 45,552 bp and 33 % G+C content. Bioinformatics analysis of the phage genome revealed 43 open reading frames. A blastn search revealed that its nucleotide sequence shared a high degree of similarity with that of the Staphylococcus phage tp310-2. In conclusion, this study is the first report to show the morphological features and the complete genome sequence of the phage SMSAP5 from soil of slaughterhouses for cattle.

Cost-effectiveness of strategies to prevent methicillin-resistant Staphylococcus aureus transmission and infection in an intensive care unit

OBJECTIVE To create a national policy model to evaluate the projected cost-effectiveness of multiple hospital-based strategies to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission and infection. DESIGN Cost-effectiveness analysis using a Markov microsimulation model that simulates the natural history of MRSA acquisition and infection. PATIENTS AND SETTING Hypothetical cohort of 10,000 adult patients admitted to a US intensive care unit. METHODS We compared 7 strategies to standard precautions using a hospital perspective: (1) active surveillance cultures; (2) active surveillance cultures plus selective decolonization; (3) universal contact precautions (UCP); (4) universal chlorhexidine gluconate baths; (5) universal decolonization; (6) UCP + chlorhexidine gluconate baths; and (7) UCP+decolonization. For each strategy, both efficacy and compliance were considered. Outcomes of interest were: (1) MRSA colonization averted; (2) MRSA infection averted; (3) incremental cost per colonization averted; (4) incremental cost per infection averted. RESULTS A total of 1989 cases of colonization and 544 MRSA invasive infections occurred under standard precautions per 10,000 patients. Universal decolonization was the least expensive strategy and was more effective compared with all strategies except UCP+decolonization and UCP+chlorhexidine gluconate. UCP+decolonization was more effective than universal decolonization but would cost $2469 per colonization averted and $9007 per infection averted. If MRSA colonization prevalence decreases from 12% to 5%, active surveillance cultures plus selective decolonization becomes the least expensive strategy. CONCLUSIONS Universal decolonization is cost-saving, preventing 44% of cases of MRSA colonization and 45% of cases of MRSA infection. Our model provides useful guidance for decision makers choosing between multiple available hospital-based strategies to prevent MRSA transmission.

The additional costs of catheter-related bloodstream infections in intensive care units

PURPOSE

The additional costs of health care-associated infections vary depending on the reimbursement systems of different countries. We estimated the additional costs of central venous catheter-related bloodstream infections (CVC-CRBSI) in Japan, which has a universal health insurance system covering all citizens.

METHODS

We conducted a retrospective matched case-control study. Twenty-two patients with CVC-CRBSI were identified among 2,148 patients treated between October 2011 and May 2014 in the intensive care unit of Tokyo Medical University Hospital (1,015 beds). Twenty-two matched controls were selected on the basis of 5 criteria. The drug and medical material costs and technical fees incurred from the date of catheter insertion until hospital discharge were examined using a fee-for-service system. The additional costs of CVC-CRBSI were calculated as the difference between the costs of cases and controls. The contribution of antimicrobial drugs and the causative microorganism to the additional drug costs were also assessed.

RESULTS

The additional costs of CVC-CRBSI were estimated at $57,090 per case. Antimicrobial agents comprised only about 10% of the additional drug costs. The additional costs of Candida infection were almost twice those of CVC-CRBSI caused by other microorganisms.

CONCLUSIONS

The additional costs of CVC-CRBSI in Japan were estimated at $57,090 per case.

Major publications in the critical care pharmacotherapy literature: January-December 2013

PURPOSE

Ten recently published articles with important implications for critical care pharmacotherapy are summarized.

SUMMARY

The Critical Care Pharmacotherapy Literature Update (CCPLU) group is a national assembly of experienced intensive care unit (ICU) pharmacists across the United States. Group members monitor 25 peer-reviewed journals on an ongoing basis to identify literature relevant to pharmacy practice in the critical care setting. After evaluation by CCPLU group members, selected articles are chosen for summarization and distribution to group members nationwide based on (1) applicability to critical care practice, (2) relevance to pharmacy practitioners, and (3) quality of evidence or research methodology. Hundreds of relevant articles were evaluated by the group during the period January-December 2013, of which 98 were summarized and disseminated nationally to CCPLU group members. Among those 98 publications, 10 deemed to be of particularly high utility to critical care practitioners were included in this review. The 10 articles address topics such as rapid lowering of blood pressure in patients with intracranial hemorrhage, adjunctive therapy to prevent renal injury due to acute heart failure, triple-drug therapy to improve neurologic outcomes after cardiac arrest, and continuous versus intermittent infusion of β-lactam antibiotics in severe sepsis.

CONCLUSION

There were many important additions to the critical care pharmacotherapy literature in 2013, including an updated guideline on the management of myocardial infarction and reports on advances in research focused on improving outcomes in patients with stroke or cardiac arrest and preventing the spread of drug-resistant pathogens in the ICU.

Economic features of antibiotic resistance: the case of methicillin-resistant Staphylococcus aureus

This paper analyses and updates the economic information regarding methicillin-resistant Staphylococcus aureus (MRSA), including information that has been previously reviewed by other authors, and new information, for the purpose of facilitating health management and clinical decisions. The analysed articles reveal great disparity in the economic burden on MRSA patients; this is mainly due to the diversity of the designs of the studies, as well as the variability of the patients and the differences in health care systems. Regarding prophylactic strategies, the studies do not provide conclusive results that could unambiguously orientate health management. The studies addressing treatments noted that linezolid seems to be a cost-effective treatment for MRSA, mostly because it is associated with a shorter length of stay (LOS) in hospital. However, important variables such as antimicrobial susceptibility, infection type and resistance emergence should be included in these analyses before a conclusion is reached regarding which treatment is the best (most efficient). The reviewed studies found that rapid MRSA detection, using molecular techniques, is an efficient technique to control MRSA. As a general conclusion, the management of MRSA infections implicates important economic costs for hospitals, as they result in higher direct costs and longer LOS than those related to methicillin-susceptible S. aureus (MSSA) patients or MRSA-free patients; there is wide variability in those increased costs, depending on different variables. Moreover, the research reveals a lack of studies on other related topics, such as the economic implications of changes in MRSA epidemiology (community patients and lineages associated with farm animals).

The combined use of NPWT and instillation using an octenidine based wound rinsing solution: a case study

Effective wound bed preparation is an essential element in the healing of chronic wounds, including pressure ulcers (PUs). Negative pressure wound therapy (NPWT) reduces oedema, stimulates the formation of granulation tissue and helps remove wound exudate. This helps prepare the wound bed for secondary healing, skin grafting or coverage with flaps. Combining NPWT with an instillation phase using an antiseptic (octenidine based) irrigation solution is a novel approach to PU management. Three patients with Category 4 gluteal PUs were treated with NPWT and instillation fluid, following surgical debridement of necrotic tissue. The aim was to achieve optimal wound bed preparation prior to wound closure by local fasciocutaneous flap. The antiseptic efficacy of octenilin wound irrigation solution in microorganism eradication was quantified by in vitro tests simulating real conditions using leg ulcer vacuum exudates. All wounds completely healed after four weeks, and no adverse incidents occurred due to instillation of octenidine. No recurrence of the PU occurred during a one year follow-up.

Real-Time Polymerase Chain Reaction Detection of Methicillin-ResistantStaphylococcus aureus:Impact on Nosocomial Transmission and Costs

Objectives.

To assess the impact of real-time polymerase chain reaction (PCR) detection of methicillin-resistantStaphylococcus aureus(MRSA) on nosocomial transmission and costs.

Design.

Monthly MRSA detection rates were measured from April 1, 2000, through December 31, 2005. Time series analysis was used to identify changes in MRSA detection rates, and decision analysis was used to compare the costs of detection by PCR and by culture.

Setting.

A 1,200-bed, tertiary care hospital in Canada.

Patients.

Admitted patients at high risk for MRSA colonization. MRSA detection using culture-based screening was compared with a commercial PCR assay.

Results.

The mean monthly incidence of nosocomial MRSA colonization or infection was 0.37 cases per 1,000 patient-days. The time-series model indicated an insignificant decrease of 0.14 cases per 1,000 patient-days per month (95% confidence interval, —0.18 to 0.46) after the introduction of PCR detection (P= .39). The mean interval from a reported positive result until contact precautions were initiated decreased from 3.8 to 1.6 days (P<.001). However, the cost of MRSA control increased from Can$605,034 to Can$771,609. Of 290 PCR-positive patients, 120 (41.4%) were placed under contact precautions unnecessarily because of low specificity of the PCR assay used in the study; these patients contributed 37% of the increased cost. The modeling study predicted that the cost per patient would be higher with detection by PCR (Can$96) than by culture (Can$67).

Conclusion.

Detection of MRSA by the PCR assay evaluated in this study was more costly than detection by culture for reducing MRSA transmission in our hospital. The cost benefit of screening by PCR varies according to incidences of MRSA colonization and infection, the predictive values of the assay used, and rates of compliance with infection control measures.

Patterns of Handwashing Behavior and Visits to Patients on a General Medical Ward of Healthcare Workers

Objective:

To obtain accurate data regarding the handwashing behavior and patterns of visits to patients by healthcare workers (HCWs).

Methods:

All visits by HCWs to selected patient rooms were recorded for 3 days and 2 nights. Additionally, 5 nurses were observed for 1 day each and 2 nurses were observed for 1 night each. Nurses were observed for their entire shifts and all of their activities were recorded.

Setting:

A general medical ward in a tertiary-care hospital.

Participants:

Convenience samples of HCWs and patients.

Results:

Patients were visited every 25 minutes on average. Monitoring rooms and observing nurses resulted in similar rates of patient visits. The highest level of risk was contact with body fluids in 11% of visits and skin in 40% of visits. The overall rate of handwashing was 46%; however, the rate was higher for visits involving contact with body fluids (81%) and skin (61%). Nurses returned immediately to the same patient 45% of the time. The rate of handwashing was higher for the last of a series of visits to a patient's room (53% vs 30%, P < .0001).

Conclusions:

Nurses adjusted their handwashing rates in accordance with the risk level of each visit. Monitoring patient rooms and observing nurses yielded similar estimates of patient visits and proportions of visits involving contact with skin or body fluids. Education programs about hand hygiene may be more effective if patterns of care and levels of risk are incorporated into recommendations.

Reduction in Hospitalwide Incidence of Infection or Colonization with Methicillin-ResistantStaphylococcus aureusWith Use of Antimicrobial Hand-Hygiene Gel and Statistical Process Control Charts

Objective.

To evaluate the impact of serial interventions on the incidence of methicillin-resistantStaphylococcus aureus(MRSA).

Design.

Longitudinal observational study before and after interventions.

Setting.

The Alfred Hospital is a 350-bed tertiary referral hospital with a 35-bed intensive care unit (ICU).

Interventions.

A series of interventions including the introduction of an antimicrobial hand-hygiene gel to the intensive care unit and a hospitalwide MRSA surveillance feedback program that used statistical process control charts but not active surveillance cultures.

Methods.

Serial interventions were introduced between January 2003 and May 2006. The incidence and rates of new patients colonized or infected with MRSA and episodes of MRSA bacteremia in the intensive care unit and hospitalwide were compared between the preintervention and intervention periods. Segmented regression analysis was used to calculate the percentage reduction in new patients with MRSA and in episodes of MRSA bacteremia hospitalwide in the intervention period.

Results.

The rate of new patients with MRSA in the ICU was 6.7 cases per 100 patient admissions in the intervention period, compared with 9.3 cases per 100 patient admissions in the preintervention period (P= .047). The hospitalwide rate of new patients with MRSA was 1.7 cases per 100 patient admissions in the intervention period, compared with 3.0 cases per 100 patient admissions in the preintervention period (P< .001). By use of segmented regression analysis, the maximum and conservative estimates for percentage reduction in the rate of new patients with MRSA were 79.5% and 42.0%, respectively, and the maximum and conservative estimates for percentage reduction in the rate of episodes of MRSA bacteremia were 87.4% and 39.0%, respectively.

Conclusion.

A sustained reduction in the number of new patients with MRSA colonization or infection has been demonstrated using minimal resources and a limited number of interventions.

The burden of nosocomial staphylococcus aureus bloodstream infection in South Korea: a prospective hospital-based nationwide study

Background

We estimated the nationwide burden of nosocomial S. aureus bloodstream infection (SA-BSI), a major cause of nosocomial infection, in South Korea.

Methods

To evaluate the nationwide incidence of nosocomial SA-BSI, cases of SA-BSI were prospectively collected from 22 hospitals with over 500 beds over 4?months. Data on patient-days were obtained from a national health insurance database containing the claims data for all healthcare facilities in South Korea. The additional cost of SA-BSI was estimated through a matched case?control study. The economic burden was calculated from the sum of the medical costs, the costs of caregiving and loss of productivity.

Results

Three hundred and thirty nine cases of nosocomial SA-BSI were included in the study: 254 cases of methicillin-resistant SA-BSI (MRSA-BSI) and 85 cases of methicillin-susceptible SA-BSI (MSSA-BSI). Death related to BSI occurred in 81 cases (31.9%) of MRSA-BSI and 12 cases (14.1%) of MSSA-BSI. The estimated incidence of nosocomial MRSA-BSI was 0.12/1,000 patient-days and that of nosocomial MSSA-BSI, 0.04/1,000 patient-days. The estimated annual cases of nosocomial BSI were 2,946 for MRSA and 986 for MSSA in South Korea. The additional economic burden per case of nosocomial SA-BSI was US $20,494 for MRSA-BSI and $6,914 for MSSA-BSI. Total additional annual cost of nosocomial SA-BSI was $67,192,559.

Conclusion

In view of the burden of nosocomial SA-BSI, a national strategy for reducing nosocomial SA-BSI is urgently needed in South Korea.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0590-4) contains supplementary material, which is available to authorized users.

Nasal screening for MRSA: different swabs--different results!

OBJECTIVES

Swab-based nasal screening is commonly used to identify asymptomatic carriage of Staphylococcus aureus in patients. Bacterial detection depends on the uptake and release capacities of the swabs and on the swabbing technique itself. This study investigates the performance of different swab-types in nasal MRSA-screening by utilizing a unique artificial nose model to provide realistic and standardized screening conditions.

METHODS

An anatomically correct artificial nose model was inoculated with a numerically defined mixture of MRSA and Staphylococcus epidermidis bacteria at quantities of 4×10(2) and 8×10(2) colony forming units (CFU), respectively. Five swab-types were tested following a strict protocol. Bacterial recovery was measured for direct plating and after elution into Amies medium by standard viable count techniques.

RESULTS

Mean recovered bacteria quantities varied between 209 and 0 CFU for MRSA, and 365 and 0 CFU for S. epidermidis, resulting swab-type-dependent MRSA-screening-sensitivities ranged between 0 and 100%. Swabs with nylon flocked tips or cellular foam tips performed significantly better compared to conventional rayon swabs referring to the recovered bacterial yield (p<0.001). Best results were obtained by using a flocked swab in combination with Amies preservation medium. Within the range of the utilized bacterial concentrations, recovery ratios for the particular swab-types were independent of the bacterial species.

CONCLUSIONS

This study combines a realistic model of a human nose with standardized laboratory conditions to analyze swab-performance in MRSA-screening situations. Therefore, influences by inter-individual anatomical differences as well as diverse colonization densities in patients could be excluded. Recovery rates vary significantly between different swab-types. The choice of the swab has a great impact on the laboratory result. In fact, the swab-type contributes significantly to true positive or false negative detection of nasal MRSA carriage. These findings should be considered when screening a patient.

Nasal Carriage and Resistance Pattern of Multidrug Resistant Staphylococcus aureus Among Healthy Children in Kashan, Iran

Background:

Nasal carriage of Staphylococcus aureus is a substantial source of human infections. Detection and treatment of nasal carriage in children with methicillin-resistant and multidrug resistant S. aureus (MRSA and MDRSA, respectively) may be an important modality in prevention of infections.

Objectives:

This study determined the prevalence, antibiotic resistance patterns and risk factors for nasal carriage of MDRSA among healthy children.

Patients and Methods:

This cross-sectional study was carried out on 350 one-month to 14-year-old healthy children in Kashan city, Iran. From all health-care centers, four were chosen by simple random sampling. Nasal samples were cultured in blood agar medium for S. aureus and antibiotic susceptibility profile was determined by disc diffusion and E-test. Risk factors for nasal carriage of MDRSA were also determined.

Results:

A total of 92 (26.3%) S. aureus isolates were obtained, of which 33 (35.9%) were MRSA and 27 (29.3%) were MDRSA. Of MRSA strains, 19 (70.4%) were MDRSA. S. aureus isolates showed 52.2% resistance to cephalothin, 33.7% to co-trimoxazole, 26.1% to clindamycin, 26.1% to ciprofloxacin, 4.3% to vancomycin, and 35.9% to oxacillin. The risk factors for nasal carriage of MDRSA were antibiotic usage during the last three months (P = 0.006), family size of more than four members (P = 0.044), and parental smoking (P = 0.045).

Conclusions:

MDRSA was not uncommon among healthy children in Kashan and prevention of its spread in the population is judicious.

The use of the temporal scan statistic to detect methicillin-resistant Staphylococcus aureus clusters in a community hospital

Background

In healthcare facilities, conventional surveillance techniques using rule-based guidelines may result in under- or over-reporting of methicillin-resistant Staphylococcus aureus (MRSA) outbreaks, as these guidelines are generally unvalidated. The objectives of this study were to investigate the utility of the temporal scan statistic for detecting MRSA clusters, validate clusters using molecular techniques and hospital records, and determine significant differences in the rate of MRSA cases using regression models.

Methods

Patients admitted to a community hospital between August 2006 and February 2011, and identified with MRSA > 48 hours following hospital admission, were included in this study. Between March 2010 and February 2011, MRSA specimens were obtained for spa typing. MRSA clusters were investigated using a retrospective temporal scan statistic. Tests were conducted on a monthly scale and significant clusters were compared to MRSA outbreaks identified by hospital personnel. Associations between the rate of MRSA cases and the variables year, month, and season were investigated using a negative binomial regression model.

Results

During the study period, 735 MRSA cases were identified and 167 MRSA isolates were spa typed. Nine different spa types were identified with spa type 2/t002 (88.6%) the most prevalent. The temporal scan statistic identified significant MRSA clusters at the hospital (n = 2), service (n = 16), and ward (n = 10) levels (P ≤ 0.05). Seven clusters were concordant with nine MRSA outbreaks identified by hospital staff. For the remaining clusters, seven events may have been equivalent to true outbreaks and six clusters demonstrated possible transmission events. The regression analysis indicated years 2009–2011, compared to 2006, and months March and April, compared to January, were associated with an increase in the rate of MRSA cases (P ≤ 0.05).

Conclusions

The application of the temporal scan statistic identified several MRSA clusters that were not detected by hospital personnel. The identification of specific years and months with increased MRSA rates may be attributable to several hospital level factors including the presence of other pathogens. Within hospitals, the incorporation of the temporal scan statistic to standard surveillance techniques is a valuable tool for healthcare workers to evaluate surveillance strategies and aid in the identification of MRSA clusters.

Natural history of colonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE): a systematic review

Background

No published systematic reviews have assessed the natural history of colonization with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE). Time to clearance of colonization has important implications for patient care and infection control policy.

Methods

We performed parallel searches in OVID Medline for studies that reported the time to documented clearance of MRSA and VRE colonization in the absence of treatment, published between January 1990 and July 2012.

Results

For MRSA, we screened 982 articles, identified 16 eligible studies (13 observational studies and 3 randomized controlled trials), for a total of 1,804 non-duplicated subjects. For VRE, we screened 284 articles, identified 13 eligible studies (12 observational studies and 1 randomized controlled trial), for a total of 1,936 non-duplicated subjects. Studies reported varying definitions of clearance of colonization; no study reported time of initial colonization. Studies varied in the frequency of sampling, assays used for sampling, and follow-up period. The median duration of total follow-up was 38 weeks for MRSA and 25 weeks for VRE. Based on pooled analyses, the model-estimated median time to clearance was 88 weeks after documented colonization for MRSA-colonized patients and 26 weeks for VRE-colonized patients. In a secondary analysis, clearance rates for MRSA and VRE were compared by restricting the duration of follow-up for the MRSA studies to the maximum observed time point for VRE studies (43 weeks). With this restriction, the model-fitted median time to documented clearance for MRSA would occur at 41 weeks after documented colonization, demonstrating the sensitivity of the pooled estimate to length of study follow-up.

Conclusions

Few available studies report the natural history of MRSA and VRE colonization. Lack of a consistent definition of clearance, uncertainty regarding the time of initial colonization, variation in frequency of sampling for persistent colonization, assays employed and variation in duration of follow-up are limitations of the existing published literature. The heterogeneity of study characteristics limits interpretation of pooled estimates of time to clearance, however, studies included in this review suggest an increase in documented clearance over time, a result which is sensitive to duration of follow-up.

Nasal carriage of multi-drug resistant Panton-Valentine leucocidin-positive methicillin-resistant Staphylococcus aureus in children in Tripoli-Libya

Methicillin-resistant Staphylococcus aureus (MRSA) colonized children are at an increased risk of developing infections than methicillin-sensitive S. aureus colonized children. Nasal specimens from inpatient children, mothers of inpatient children, healthcare workers, and outpatient children at Tripoli Children Hospital (TCH) were examined for MRSA by chromogenic MRSA ID medium. Susceptibility of MRSA isolates to antibiotics was determined by the disc diffusion method. The nasal carriage rate of MRSA among inpatient children (8.3%, 24 of 289), their mothers (11%, 22 of 200), and healthcare workers (12.4%, 22 of 178) was significantly higher than among outpatient children (2.2%, 2 of 91) (P < 0.05, P < 0.02, and P < 0.006, respectively). Of the examined MRSA isolates (N = 35) 10 (28.6%) were positive for Panton-Valentine leucocidin genes by polymerase chain reaction. Multidrug resistance was found in 24.3% (17 of 70) of MRSA isolates. Nasal carriage of multidrug-resistant Panton-Valentine leucocidin-positive MRSA is not uncommon among inpatient children and their mothers in Tripoli.

Cost comparison of linezolid versus vancomycin for treatment of complicated skin and skin-structure infection caused by methicillin-resistant Staphylococcus aureus in Quebec

BACKGROUND

In Canada, complicated skin and skin-structure infection (cSSSI) caused by methicillin-resistant Staphylococcus aureus (MRSA) is usually treated with antibiotics in hospital, with a follow-up course at home for stable patients. The cost implications of using intravenous and oral linezolid instead of intravenous vancomycin in Canadian clinical practice have not been examined.

OBJECTIVES

To evaluate the potential treatment cost impact for the Quebec health care system of linezolid versus vancomycin for MRSA-related cSSSI therapy, using a net impact analysis approach.

METHODS

Health care resource use associated with linezolid and vancomycin therapy was estimated for patients in Quebec, based on expert opinion. Costs were assigned to health care resources (antibiotics, medical supplies, laboratory testing and health care professional time) based on unit prices. The base-case analysis assumed 14 days of antibiotic treatment for both agents; five days in hospital followed by nine days at home. Therapy duration, length of inpatient treatment and discharge rates were varied in sensitivity analyses.

RESULTS

Antibiotic costs were higher for linezolid than for vancomycin, for both inpatient ($874 versus $144, respectively) and outpatient therapy ($1,356 versus $1,242, respectively). Compared with vancomycin, lower costs for antibiotic preparation, administration and monitoring of linezolid offset drug acquisition costs. Total treatment costs were $3,850 for linezolid versus $5,189 for vancomycin. Results were sensitive to the number of treatment days spent at home and the discharge rate.

CONCLUSION

Using linezolid instead of vancomycin to treat MRSA-related cSSSI, for hospital and home courses combined, may reduce health care resource utilization and costs in Quebec.

Cost-effectiveness and efficacy of spa, SCCmec, and PVL genotyping of methicillin-resistant Staphylococcus aureus as compared to pulsed-field gel Electrophoresis

Pulsed-field gel electrophoresis (PFGE) is a valuable molecular typing assay used for methicillin-resistant Staphylococcus aureus (MRSA) surveillance and genotyping. However, there are several limitations associated with PFGE. In Alberta, Canada, the significant increase in the number of MRSA isolates submitted to the Provincial Laboratory for Public Health (ProvLab) for PFGE typing led to the need for an alternative genotyping method. In this study, we describe the transition from PFGE to Staphylococcus protein A (spa), Staphylococcal cassette chromosome (SCCmec), and Panton-Valentine leukocidin (PVL) typing. A total of 1915 clinical MRSA isolates collected from 2005 to 2009 were used to develop and validate an algorithm for assigning PFGE epidemic types using spa, SCCmec, and PVL typing and the resulting data was used to populate a new Alberta MRSA typing database. An additional 12620 clinical MRSA isolates collected from 2010 to 2012 as part of ongoing routine molecular testing at ProvLab were characterized using the new typing algorithm and the Alberta MRSA typing database. Switching to spa, SCCmec, and PVL from PFGE typing substantially reduced hands-on and turn-around times while maintaining historical PFGE epidemic type designations. This led to an approximate $77,000 reduction in costs from 2010 to 2012. PFGE typing is still required for a small subset of MRSA isolates that have spa types that are rare, novel, or associated with more than one PFGE epidemic type.

Risk factors for methicillin-resistant Staphylococcus aureus bacteraemia differ depending on the control group chosen

Methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia cause significant morbidity and mortality in hospitalized patients. Using a nested case-control design, 204 MRSA bacteraemia cases were compared to 301 unmatched methicillin-susceptible Staphylococcus aureus (MSSA) bacteraemia controls and were matched 1:2 with non-infected controls. The independent risk factors for MRSA bacteraemia compared to MSSA bacteraemia were older age (P = 0·048), major organ transplant during current hospital stay (P = 0·016) and quinolone use (P = 0·016). Cases were more likely than non-infected controls to have renal failure (P = 0·003), cirrhosis (P = 0·013), and a central venous catheter (P = 0·003) after controlling for other risk factors. This large case-control study made it possible to assess risk factors for MRSA bacteraemia using two sets of controls and showed that risk factors differed greatly depending on the control group chosen. These results confirm the need for careful selection of appropriate control groups and the need to carefully adjust for underlying severity of illness.

Evaluation of three methods for detection of methicillin-resistant Staphylococcus aureus

AIM: To evaluate GenoType methicillin-resistant Staphylococcus aureus (MRSA) Direct assay and cultivation for the identification of MRSA by using mecA polymerase chain reaction (PCR) as the “gold standard” assay.

METHODS: In total of 61 nasal specimens from patients at the intensive care unit were studied by GenoType MRSA Direct test, conventional culture method and automated bacterial identification system. The results of GenoType MRSA Direct assay were compared to conventional culture method the identification of MRSA and mecA gene PCR as the “gold standard” method. The sensitivity, specificity, positive predictive value and negative predictive value were calculated.

RESULTS: In total, 61 specimens were studied. Fifty-four specimens (88.5%) were negative by all three methods. Six swabs (9.8%) were found positive by GenoType MRSA Direct test, conventional culture method and automated bacterial identification system. The presence of mecA in these strains was confirmed by PCR. One swab sample was negative for culture methods but MRSA and mecA gene were detected by GenoType MRSA Direct test and mecA PCR respectively. GenoType MRSA Direct test had a sensitivity of 100% (6/6) and a specificity of 100% (55/55), with a positive predictive value of 100% and a negative predictive value of 98%. Culture method of MRSA had a sensitivity of 83.3% (5/6) and a specificity of 98.2% (55/56).

CONCLUSION: It was found that the GenoType MRSA Direct assay, which is a rapid and accurate test, is of the same sensitivity and specificity with mecA PCR. The GenoType MRSA Direct assay can be a better tool for rapid and accurate detection of MRSA in diagnostic laboratories.

Prevalence and predictors of MRSA, ESBL, and VRE colonization in the ambulatory IBD population

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) patients may be at increased risk of acquiring antibiotic-resistant organisms (ARO). We sought to determine the prevalence of colonization of methicillin-resistant Staphylococcus aureus (MRSA), Enterobacteriaceae containing extended spectrum beta-lactamases (ESBL), and vancomycin-resistant enterococi (VRE) among ambulatory IBD patients.

METHODS

We recruited consecutive IBD patients from clinics (n=306) and 3 groups of non-IBD controls from our colon cancer screening program (n=67), the family medicine clinic (n=190); and the emergency department (n=428) from the same medical center in Toronto. We obtained nasal and rectal swabs for MRSA, ESBL, and VRE and ascertained risk factors for colonization.

RESULTS

Compared to non-IBD controls, IBD patients had similar prevalence of colonization with MRSA (1.5% vs. 1.6%), VRE (0% vs. 0%), and ESBL (9.0 vs. 11.1%). Antibiotic use in the prior 3 months was a risk factor for MRSA (OR, 3.07; 95% CI: 1.10-8.54), particularly metronidazole. Moreover, gastric acid suppression was associated with increased risk of MRSA colonization (adjusted OR, 7.12; 95% CI: 1.07-47.4). Predictive risk factors for ESBL included hospitalization in the past 12 months (OR, 2.04, 95% CI: 1.05-3.95); treatment with antibiotics it the past 3 months (OR, 2.66; 95% CI: 1.37-5.18), particularly prior treatment with vancomycin or cephalosporins.

CONCLUSIONS

Ambulatory IBD patients have similar prevalence of MRSA, ESBL and VRE compared to non-IBD controls. This finding suggests that the increased MRSA and VRE prevalence observed in hospitalized IBD patients is acquired in-hospital rather than in the outpatient setting.

Three methods for estimating days of hospitalization because of hospital-acquired infection: a comparison

OBJECTIVES

The objective of this study is to compare the three methods internationally used for estimating days of hospitalization attributable to hospital infections by applying them to the same population. The methods are: (1) unmatched comparison group; (2) matched control method-based; and (3) Appropriateness Evaluation Protocol method. A study of the prevalence of infections was performed among patients during hospitalization for an ordinary single sampling department. The survey was completed within eight working days between 15 and 24 October 2007. All patients admitted at least 24 hours to the survey day in each department were included in the study, as well as patients discharged/transferred to another hospital or department. During the prevalence study 621 patients were observed, 70 of which with infection (equal to 11.27%).

METHOD

The 70 uninfected patients needed for comparison using method 1 were selected through a procedure based on propensity score on demographic variables and clinical trials of patients. The Shapiro-Wilk test was used to verify the normality of quantitative variables. In comparing the three methods Kruskall-Wallis test was used (alpha = 0.05), while comparisons between pairs of methods were performed with the Mann-Whitney test (alpha = 0.017).

RESULTS

Estimation results of recovery days with infection using the three comparison tests showed that there is a statistically significant difference between the three methods (P = 0.016) and there is a significant difference between 1 versus 3 (P = 0.013) and between 2 and 3 (P = 0.017), whereas between 1 and 2 no difference was found (P = 0.82).

CONCLUSION

In conclusion, the three methods are not showing the same estimations and thus may not be exchangeable.

HIC@RE … and its relevance for a company like RIEMSER

The increased incidence of infections caused by methicillin-resistant strains of Staphylococcus aureus (MRSA) burdens the healthcare systems with significant additional costs. Simple measures such as active MRSA screening can lead to a reduction of infectious events and massive savings. To establish an effective and comprehensive strategy for prevention and eradication of MRSA, the cooperation and networking of all stakeholders in the health care system is necessary. Pharmaceutical companies are part of the health care system; they therefore have a vital and ethical interest that care within the health system will be further optimized and thus continue to remain affordable. The targets of the HIC@RE project demonstrate the interests of the pharmaceutical and health-care research company RIEMSER Arzneimittel AG, so that a sufficient rationale is given for cooperation in this project.

Effect of patterns of transferring patients among healthcare institutions on rates of nosocomial methicillin-resistant Staphylococcus aureus transmission: a Monte Carlo simulation

OBJECTIVE

To determine the effect of the rate and pattern of patient transfers among institutions within a single metropolitan area on the rates of methicillin-resistant Staphylococcus aureus (MRSA) transmission among patients in hospitals and nursing homes.

METHODS

A stochastic, discrete-time, Monte Carlo simulation was used to model the rate and spread of MRSA transmission among patients in medical institutions within a single metropolitan area. Admission, discharges, transfers, and nosocomial transmission were simulated with respect to different interinstitutional transfer strategies and various situational scenarios, such as outlier institutions with high transmission rates.

RESULTS

The simulation results indicated that transfer patterns and transfer rate changes do not affect nosocomial MRSA transmission. Outlier institutions with high transmission rates affect the system wide rate of nosocomial infections differently, depending on institution type.

CONCLUSION

It is worth effort to understanding disease-transmission dynamics and interinstitutional transfer patterns for the management of recently introduced diseases or strains. Once endemic in a system, other strategies for transmission control need to be implemented.