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

Impact of a multipronged education strategy on antibiotic prescribing in Quebec, Canada

BACKGROUND

Antibiotic overuse and resistance have become a major threat in the last 2 decades. Many programs tried to optimize antibiotic consumption in the inpatient setting, but the outpatient environment that represents the bulk of antibiotic use has been challenging. Following a significant rise of Clostridium difficile infections, all the health care stakeholders in the province of Quebec, Canada initiated a global education program targeting physicians and pharmacists.

METHODS

A bundle approach was used; 11 user-friendly guidelines were produced by a group of experts and sent to all physicians and pharmacists in Quebec in January 2005. Downloadable versions of guidelines were posted on a dedicated Web site. They were promoted by professional organizations, universities, and experts during educational events, and there was strong acceptance by the pharmaceutical industry with a willingness to follow the recommendations in their marketing. The Intercontinental Medical Statistics (IMS) database was used to analyze and compare Quebec's total outpatient prescriptions per 1000 inhabitants with those in the other Canadian provinces for 2 time periods: preintervention (January 2003 to December 2004), and postintervention (February 2005 to December 2007).

RESULTS

In 2004, antibiotic consumption per capita was 23.3% higher in Canada generally than in Quebec. After the guidelines dissemination, the gap between Quebec and the other Canadian provinces increased by 4.1 prescriptions/1000 inhabitants (P = .0002), and the trend persisted 36 months later. Antibiotic costs fell $134.5/1000 inhabitants in Quebec compared with the rest of Canada (P = .054).

CONCLUSIONS

The implementation of guidelines significantly reduced antibiotic prescriptions in Quebec compared with the rest of the country, and there was a strong trend toward significant cost reduction.

A retrospective analysis of practice patterns in the treatment of methicillin-resistant Staphylococcus aureus skin and soft tissue infections at three Canadian tertiary care centres

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) infections are increasingly being encountered and pose an increasing burden to the health care system in Canada.

OBJECTIVE

To elucidate and characterize the factors influencing the current MRSA treatment patterns in patients with skin and soft tissue infections (SSTIs) before linezolid became available on the Canadian market.

METHODS

A retrospective study collected demographic, treatment and resource use data on patients hospitalized at one of three geographically distinct tertiary care facilities, where MRSA SSTI treatment was initiated with intravenous (IV) vancomycin. Analysis of opportunities for IV-to-oral switch therapy was based on eligibility criteria.

RESULTS

Of 89 patients identified over a 43-month period, the mean (+/-SD) durations of anti-infective treatment and hospitalization were 22.4+/-21 days and 28.9+/-20.8 days, respectively. An infected surgical wound was most common, representing 62.9% of infections. The mean duration of vancomycin treatment was 19.5 days and the mean number of 1 g doses received was 29.0+/-32.9. The majority of patients (55.1%) initiated vancomycin therapy a mean of 5.4+/-8.9 days after confirmation of MRSA. Of the 70% of patients meeting criteria for IV-to-oral switch therapy, only 10% received oral treatment. The most common reason cited for not switching was lack of an effective oral alternative. Analysis of switch therapy criteria found that IV treatment continued for a mean of 13 days despite the appropriateness of the oral route.

CONCLUSIONS

Considerable variation exists in treatment patterns for MRSA infections. Improvements in the initiation of therapy and the use of IV-to-oral switch therapy may improve care and reduce the duration of hospitalization for MRSA SSTIs.

Decolonization of methicillin-resistant Staphylococcus aureus during routine hospital care: Efficacy and long-term follow-up

BACKGROUND/OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) colonization is associated with a significant risk of subsequent MRSA infection in the hospital setting. The use of decolonization as an infection control strategy remains highly controversial despite publications evaluating more than 40 different decolonization regimens over the past 60 years. The present study describes the benefits and potential drawbacks of such an approach in the patient population.

METHODS

A retrospective cohort study was performed to assess the efficacy and subsequent outcome for patients with newly identified MRSA colonization at the Horizon Health Network in Moncton, New Brunswick.

RESULTS

A total of 241 patients with MRSA colonization or infection during the study period (2000 to 2005 inclusive) were identified. Eighty-nine MRSA-positive patients were decolonized according to a standardized regimen (hospital protocol group), and 98 received an alternative decolonization regimen (other treatment group). No attempt at decolonization was made for 54 patients (no treatment group). The hospital protocol group demonstrated superior overall successful decolonization compared with the other treatment group (67 of 84 [80%] versus 48 of 89 [54%]; OR 3.3; 95% CI 1.6 to 7.1; P=0.0004) and the no treatment group (four of 43 [9%]; OR 36.9; 95% CI 11.2 to 161.7; P<0.000001). The mean observed duration of culture negativity for the subgroup who remained MRSA culture negative over the long term was 419±398 days (range one to 1817 days). Successful decolonization occurred in 115 patients and permitted subsequent release from contact isolation for 4530 patient-days. The rate of clinical infection with MRSA was significantly lower in the hospital protocol group versus the other treatment group (16 of 89 [18%] versus 37 of 98 [38%]; OR 0.38; 95% CI 0.18 to 0.78; P=0.003).

CONCLUSION

The present study supports recent reports indicating that MRSA decolonization can be successful using a multifactorial approach (chlorhexidine soap, enhanced hygiene/housekeeping and combination oral/topical antimicrobial therapy) in hospitalized patients, both over the short and long term. Unlike previous studies, decolonization appeared to be effective in a relatively unselected population, including patients with lines and catheters. Inability to decolonize was most closely associated with failure to use a standardized decolonization protocol.

Clinical practice guidelines for hospital-acquired pneumonia and ventilator-associated pneumonia in adults

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are important causes of morbidity and mortality, with mortality rates approaching 62%. HAP and VAP are the second most common cause of nosocomial infection overall, but are the most common cause documented in the intensive care unit setting. In addition, HAP and VAP produce the highest mortality associated with nosocomial infection. As a result, evidence-based guidelines were prepared detailing the epidemiology, microbial etiology, risk factors and clinical manifestations of HAP and VAP. Furthermore, an approach based on the available data, expert opinion and current practice for the provision of care within the Canadian health care system was used to determine risk stratification schemas to enable appropriate diagnosis, antimicrobial management and nonantimicrobial management of HAP and VAP. Finally, prevention and risk-reduction strategies to reduce the risk of acquiring these infections were collated. Future initiatives to enhance more rapid diagnosis and to effect better treatment for resistant pathogens are necessary to reduce morbidity and improve survival.

The management of infection and colonization due to methicillin-resistant Staphylococcus aureus: A CIDS/CAMM position paper

Methicillin-resistant Staphylococcus aureus (MRSA) is being seen with greater frequency in most hospitals and other health care facilities across Canada. The organism may cause life-threatening infections and has been associated with institutional outbreaks. Several studies have confirmed that MRSA infection is associated with increased morbidity and mortality compared with infections caused by susceptible strains, even when the presence of comorbidities is accounted for. Treatment of MRSA infection is complicated by the fact that these organisms are resistant to multiple antimicrobial agents, so treatment options are limited. The effectiveness of decolonization therapy (attempting to eradicate MRSA carriage) is also uncertain. This paper reviews the medical management of MRSA infections, discusses the potential role of decolonization and provides an overview of evidence to support recommended infection control practices.

Quantification and analysis of airborne bacterial characteristics in a nursing care institution

Indoor air quality has become a critical issue because people spend most of their time in the indoor environment. The factors that influence indoor air quality are very important to environmental sanitation and air quality improvement. This study focuses on monitoring air quality, colony counts, and bacteria species of the indoor air of a nursing care institution. The regular colony counts in two different wards range from 55 to 600 cfu m(-3) Regression analysis results indicate that the bacterial colony counts have close correlation with relative humidity or carbon dioxide (CO2) but not with carbon monoxide (CO) or ozone (O3). Real-time PCR was used to quantify the bacterial pathogens of nosocomial infection, including Acinetobacter baumannii, Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, and methicillin-sensitive Staphylococcus aureus. The most abundant bacteria species in the air of the nursing care institution is E. coli.

Healthcare costs of methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa infections in veterans: role of vitamin D deficiency

Methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) infections are frequently associated with hospitalization and increased healthcare costs. Vitamin D deficiency may contribute to increased costs for patients with these infections and there is evidence that vitamin D may have an antimicrobial role. To evaluate the role of vitamin D deficiency in the costs incurred with these infections, we studied the relationship of serum 25(OH)D levels to healthcare costs in veterans in the southeastern United States. Patients with both infections were vitamin D deficient to a similar extent and so were combined for further analysis. Vitamin D deficient patients had higher costs and service utilization than those who were not vitamin D deficient. Those with vitamin D deficiency had higher inpatient costs compared to the non-deficient group, and this difference was across most categories except for the number of inpatient hospitalizations or total number of days as an inpatient. Vitamin D deficiency was not significantly related to outpatient cost or service utilization parameters. We conclude that vitamin D deficiency is intimately linked to adverse healthcare costs in veterans with MRSA and P. aeruginosa infections. Vitamin D status should be assayed in patients with these infections.

Characterization of Staphylococcus aureus isolates with a partial or complete absence of staphylococcal cassette chromosome elements

Detection of methicillin-resistant Staphylococcus aureus (MRSA) by single-locus PCR assays that target the extremity of the staphylococcal cassette chromosome-mec (SCCmec) and part of the adjacent S. aureus-specific open reading frame gene (orfX) is a significant diagnostic advancement, since it provides real-time detection directly from screening specimens. However, isolates harboring mecA deletions within SCCmec may result in false-positive identification of MRSA in these assays. We characterized 24 methicillin-susceptible S. aureus (MSSA) isolates that tested positive in one such assay to investigate this phenomenon. Seven isolates resembled USA100 and carried SCCmec II elements with mecA deletions that spanned 20 to 46 kbp. The mecA excisions in USA100-resembling isolates appeared to be linked with IS431 transposable elements present in SCCmec II. For 17 isolates that resembled USA400 and/or MSSA476, the identity and possible excision of SCC elements could not be confirmed. The downstream common sequence (dcs) shared by SCCmec I, II, and IV elements was detected in these isolates. Sequence analysis of the chromosomal regions flanking the missing SCC element revealed an intact SCC integration site, a duplicate dcs, and the enterotoxin gene cluster downstream of orfX. An annealing sequence for one of the SCCmec-specific primers (mecii574) in the single-locus PCR assay was identified in the duplicate dcs. In the absence of SCC, a 176-bp amplicon can be generated from this mecii574 annealing sequence to yield a false-positive result. In conclusion, partial SCCmec II excisions via IS431 elements in strains that resembled USA100 and the presence of a duplicate mecii574 annealing sequence in strains that resembled USA400/MSSA476 were identified as causes for false-positive results in a single-locus PCR assay that targets the SCCmec/orfX junction.

Excess costs and utilization associated with methicillin resistance for patients with Staphylococcus aureus infection

OBJECTIVE

To determine differences in healthcare costs between cases of methicillin-susceptible Staphylococcus aureus (MSSA) infection and methicillin-resistant S. aureus (MRSA) infection in adults.

DESIGN

Retrospective study of all cases of S. aureus infection.

SETTING

Department of Veterans Affairs hospital and associated clinics.

PATIENTS

There were 390 patients with MSSA infections and 335 patients with MRSA infections.

METHODS

We used medical records, accounting systems, and interviews to identify services rendered and costs for Minneapolis Veterans Affairs Medical Center patients with S. aureus infection with onset during the period from January 1, 2004, through June 30, 2006. We used regression analysis to adjust for patient characteristics.

RESULTS

Median 6-month unadjusted costs for patients infected with MRSA were $34,657, compared with $15,923 for patients infected with MSSA. Patients with MRSA infection had more comorbidities than patients with MSSA infection (mean Charlson index 4.3 vs 3.2; P < .001). For patients with Charlson indices of 3 or less, mean adjusted 6-month costs derived from multivariate analysis were $51,252 (95% CI, $46,041-$56,464) for MRSA infection and $30,158 (95% CI, $27,092-$33,225) for MSSA infection. For patients with Charlson indices of 4 or more, mean adjusted costs were $84,436 (95% CI, $79,843-$89,029) for MRSA infection and $59,245 (95% CI, $56,016-$62,473) for MSSA infection. Patients with MRSA infection were also more likely to die than were patients with MSSA infection (23.6% vs 11.5%; P < .001). MRSA infection was more likely to involve the lungs, bloodstream, and urinary tract, while MSSA infection was more likely to involve bones or joints; eyes, ears, nose, or throat; surgical sites; and skin or soft tissue (P < .001).

CONCLUSIONS

Resistance to methicillin in S. aureus was independently associated with increased costs. Effective antimicrobial stewardship and infection prevention programs are needed to prevent these costly infections.

Systematic patients' hand disinfection: impact on meticillin-resistant Staphylococcus aureus infection rates in a community hospital

The role of patients and their relatives as unidentified transient meticillin-resistant Staphylococcus aureus (MRSA) carriers and sources of dissemination in healthcare institutions has not been systematically addressed. Patients' and their relatives' hands may represent a substantial and 'unaccounted for' mode of transmission. This study aimed to verify this hypothesis in our 250-bed community hospital. The trial consisted of a systematic waterless washing and gel rinse disinfection of all patients' and visiting relatives' hands for a period of one year, along with retrospective comparison of the nosocomial infection rates. Under the supervision of infection control personnel, a team of four full-time and four part-time attendants was trained to meet all patients and visiting relatives and encourage them to clean their hands with an alcohol gel rinse twice a day on every weekday. Rates of MRSA infections per thousand admissions, cost-benefit analysis and staff hand hygiene compliance were audited throughout. From the comparative year, the rate of MRSA nosocomial infections per thousand admissions decreased by 51%. Assuming that the incidence of MRSA was maintained from comparative to study year, the intervention may have prevented 51 cases of MRSA infection and resulted in substantial savings. While focusing extensively on staff behaviour to prevent MRSA transmission, we may have overlooked hand hygiene practices by patients and their relatives as a potential mode of transmission. Systematic hand hygiene of patients and relatives appears to be an inexpensive and highly effective preventive measure against MRSA nosocomial transmission.

Methicillin-resistant Staphylococcus aureus in Canada: a historical perspective and lessons learned

The history of methicillin-resistant Staphylococcus aureus (MRSA) in Canada has many similarities to MRSA evolution worldwide, but especially to that in the United States and United Kingdom. Reports of MRSA occurred as early as 1964, and community isolates were cited in the 1970s. Nosocomial outbreaks were becoming common by 1978 and flourished gradually thereafter. Endemic institutional MRSA became predominant in the 1990s, threatening large teaching hospitals in particular. In the last decade, both hospital-acquired and community-acquired MRSA have created major medical problems in Canada. More recently, an epidemic of Canadian community-acquired MRSA-10, has led to heightened public health concerns. Canadian contributions to MRSA science are numerous, with organized surveillance continuing to mature across the nation. A typing system for epidemic clones is now available and is being judiciously applied. Estimated costs for MRSA surveillance, treatment, and control are extraordinary, paralleling the dramatic rise in the number of MRSA isolations. Whereas surveillance continues to form an essential aspect of MRSA management, control, eradication, and overall diminution, MRSA reservoirs deserve much greater attention. Such efforts, however, must be as widely publicized in the community and in patient homes as they are in medical institutions responsible for both acute and long-term care.

Health economic issues in the treatment of drug-resistant serious Gram-positive infections

Escalating health care costs have stimulated a paradigm change in the way health care is delivered, reimbursed, and evaluated. Reducing the length of hospital stay and controlling the cost of new technologies and therapies are major factors driving health care decisions. Economic evaluations have had variable success in the decision-making process, partly due to the overall quality, interpretation, and reporting of published analyses. Compared with other Gram-positive pathogens, the economic impact of methicillin-resistant Staphylococcus aureus (MRSA) infections remains the most studied. MRSA infections clearly represent a significant clinical and fiscal burden and future studies analyzing cost-effective strategies that encompass their prevention and optimal management would be beneficial. These studies would need to be carefully designed with clear objectives and explicit perspectives at the onset. Use of an appropriate reference group is key in the design process to measure the true impact of MRSA infections. Health-economic outcome data of the impact of linezolid compared with glycopeptides remain the most robust data available in this therapeutic area.

Update: Methicillin-resistant Staphylococcus aureus screening and decolonization in cardiac surgery

Methicillin-resistant Staphylococcus aureus (MRSA) has become a concerning multidrug-resistant organism, expanding further outside the hospital setting. Cardiothoracic surgery patients are at an increased risk for mediastinitis and other surgical site infections, which may be further complicated by MRSA. To reduce MRSA surgical site infections, multidisciplinary active surveillance should be implemented in at least high-risk patients, incorporating basic infection control practices, appropriate antibiotic prophylaxis, and decolonization. This article will review the various guidelines, addressing the role of MRSA active surveillance in cardiothoracic surgery, and provide guidance for cardiothoracic surgeons.

Cost-effectiveness of rapid MRSA screening in surgical patients

This study investigates the effectiveness of a same-day polymerase chain reaction (PCR) test for the rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) in a general screening of patients admitted to the trauma surgery and heart surgery department in a German university hospital. A total of 442 patients were screened over a 4-month period by using a PCR assay, compared to culture methods, for specimens from the nose and throat. The MRSA carriage rate on admission was 3.85% during the study period. The PCR results of 1,680 swabs showed a sensitivity of 85% and a specificity of 99.39% for swabs from the nares and for the throat 42.11% and 98.78%, respectively. A combination of specimens from the nose and throat from the same patient led to a sensitivity of 100% with a specificity of 98.29%. Cost calculation under the circumstances of a diagnosis-related groups (DRG) payment system found that the eight MRSA-positive patients created costs of 38,472 euros, i.e. 4,809 euros per patient, facing screening costs of 36.62 euros per sample. Screening patients by using the rapid PCR assay for a combination of specimens from the nose and throat would offer a safe and cost-effective way of MRSA screening on admission.

Are there differences in hospital cost between patients with nosocomial methicillin-resistant Staphylococcus aureus bloodstream infection and those with methicillin-susceptible S. aureus bloodstream infection?

OBJECTIVE

To examine the impact of methicillin resistance on in-hospital mortality, length of stay, and hospital cost after the onset of nosocomial Staphylococcus aureus bloodstream infection (BSI).

DESIGN

A retrospective cohort study.

SETTING

A tertiary care hospital in Rhode Island.

PATIENTS

A cohort of 182 consecutive patients who developed nosocomial BSI due to methicillin-susceptible and methicillin-resistant S. aureus (MSSA and MRSA, respectively)

RESULTS

Patients with MRSA BSI had a significantly longer total length of hospital and intensive care unit (ICU) stay before the onset of BSI and a higher average daily cost. Compared with ICU patients with MSSA BSI, those with MRSA BSI had a higher median total hospital cost ($42,137 vs $113,852), higher hospital cost after infection ($17,603 vs $51,492), and greater length of stay after infection (10.5 vs 20.5 days). After multivariable adjustment, ICU patients with MRSA BSI had significantly increased total hospital cost, hospital cost after infection, and length of stay after infection. However, using a propensity score approach, we found that, among ICU patients, the difference in cost after infection and the difference in length of stay after infection for MRSA, compared with MSSA BSI, were not significant. The differences among non-ICU patients who developed MRSA or MSSA BSI were not significant after multivariable adjustment or by propensity score.

CONCLUSIONS

On the basis of propensity score, we found that methicillin resistance did not independently increase hospital cost or length of stay after onset of S. aureus BSI. We believe that use of a propensity score on a comparable subset of patients may be a better method than multivariable adjustment for assessing the impact of methicillin resistance in cohort studies.

CE-based detection of methicillin-resistant Staphylococcus aureus

Rapid and sensitive detection of methicillin-resistant Staphylococcus aureus is crucial for effective treatment and control of clinical infections caused by this bacterium. The goal of this study is to develop a CE-based detection method for multiplexed identification of a femA sequence specific for S. aureus and a unique mecA sequence encoding methicillin resistance. Blood samples spiked with known concentrations of bacteria were used for testing. Crude cell lysates were prepared by treating the spiked blood samples with DNazol Direct reagent and used as the template for isothermal amplification of mecA and femA genes. The amplified gene products then underwent a cycling probe reaction (CPR)-based assay to generate a short fluorophore-labeled oligonucleotide for detection in a CZE-LIF system. The assay enables a gene-specific fluorophore-labeled DNA-RNA-DNA chimeric probe to hybridize with complementary target in the presence of RNase H enzyme. The RNase H enzyme specifically cleaves probe RNA residues of the duplex, releasing a fluorophore fragment for detection and the target for recycling and hybridization with another chimeric probe. Intact and cleaved probe fragments were separated and detected using a CZE-LIF system. The limit of detection for isothermal amplification and CPR-CZE-LIF was approximately 10(4) colony-forming units of bacteria/mL of blood. This method accurately detects methicillin-resistant S. aureus within 3 h.

Comparison of the DiversiLab system, Pulsed-Field Gel Electrophoresis and Multi-Locus Sequence Typing for the characterization of epidemic reference MRSA strains

We have analyzed a representative selection of the HARMONY meticillin-resistant Staphylococcus aureus strain collection originating from 11 European countries (Cookson, B.D. et al., 2007, J. Clin. Microbiol. 45: 1830-1837) with the DiversiLab System, Pulsed-Field Gel Electrophoresis (PFGE) and Multi-Locus Sequence Typing (MLST). Simpson's diversity indices were 0.905, 0.877 and 0.860 for PFGE, MLST and DiversiLab, respectively. All methods displayed concordant classification of the MRSA strains, although with divergent resolution and reproducibility.

A randomized controlled trial of tea tree oil (5%) body wash versus standard body wash to prevent colonization with methicillin-resistant Staphylococcus aureus (MRSA) in critically ill adults: research protocol

Background

Over the past ten years MRSA has become endemic in hospitals and is associated with increased healthcare costs. Critically ill patients are most at risk, in part because of the number of invasive therapies that they require in the intensive care unit (ICU). Washing with 5% tea tree oil (TTO) has been shown to be effective in removing MRSA on the skin. However, to date, no trials have evaluated the potential of TTO body wash to prevent MRSA colonization or infection. In addition, detecting MRSA by usual culture methods is slow. A faster method using a PCR assay has been developed in the laboratory, but requires evaluation in a large number of patients.

Methods/Design

This study protocol describes the design of a multicentre, phase II/III prospective open-label randomized controlled clinical trial to evaluate whether a concentration of 5% TTO is effective in preventing MRSA colonization in comparison with a standard body wash (Johnsons Baby Softwash) in the ICU. In addition we will evaluate the cost-effectiveness of TTO body wash and assess the effectiveness of the PCR assay in detecting MRSA in critically ill patients. On admission to intensive care, swabs from the nose and groin will be taken to screen for MRSA as per current practice. Patients will be randomly assigned to be washed with the standard body wash or TTO body wash. On discharge from the unit, swabs will be taken again to identify whether there is a difference in MRSA colonization between the two groups.

Discussion

If TTO body wash is found to be effective, widespread implementation of such a simple colonization prevention tool has the potential to impact on patient outcomes, healthcare resource use and patient confidence both nationally and internationally.

Trial Registration

[ISRCTN65190967]

Detection of early liver fibrosis in patients with intestinal schistosomiasis: sonographic and histologic findings in Schistosoma mansoni infection

BACKGROUND

Ultrasound (US) is a quite economical and noninvasive technique for morbidity assessment in intestinal schistosomiasis and it is widely used in order to detect organ-specific schistosomiasis-associated changes even if it may be invalidated by low reproducibility of measurements and high interobserver variance. Reports on histological assessment in patients with intestinal schistosomiasis mansoni are unusual because liver biopsy is not commonly feasible in endemic areas and it is not warranted for ethical reasons. This short report is a retrospective analysis of sonographic and histologic findings in patients with early liver pathology, in view of the pathogenesis and morbidity assessment of intestinal schistosomiasis, in a European hospital setting.

PATIENTS AND METHODS

Seven immigrants from Madagascar with chronic diarrhea or Schistosoma mansoni egg detection in feces were admitted to our department. All of them were subjected to clinical, biochemical and ultrasound examination following current World Health Organization (WHO) guidelines. Each patient underwent percutaneous liver biopsy.

RESULTS

Abdominal ultrasonography showed schistosomiasis image patterns or US signs of liver involvement only in one out of seven patients while histological findings showed dense discrete fibrous tissue formation in five out of seven patients. In three out of seven patients liver biopsy also showed inflammatory infiltration of eosinophils and macrophages with periportal granulomas with S. mansoni eggs. Considering the mean egg intensity of three stool specimens as the gold standard, US showed a sensitivity of 16% with a negative predictive value (NPV) of 16% and a specificity of 100% with a positive predictive value (PPV) of 100%. Liver biopsy showed a sensitivity of 83% with a NPV of 50% and a specificity of 100% with a PPV of 100%.

CONCLUSION

In our small study, US seemed to underestimate hidden liver fibrosis in intestinal schistosomiasis. In some European clinical settings, histological evaluation by liver biopsy may be a useful tool to detect early liver pathology in schistosomiasis mansoni. These findings could provide additional information for studies from endemic areas where US is commonly used for morbidity assessment.

[Impact on morbidity and costs of methicillin-resistant Staphylococcus aureus nosocomial pneumonia in intensive care patients]

OBJECTIVES

Prevention of methicillin-resistant Staphylococcus aureus (MRSA) nosocomial infections in the intensive care units (ICU) has been recommended for several years. However, the workload and the costs of these programs are to be weighed against the benefit obtained in terms of reduction of morbidity and costs induced by the infection. The purpose of this study was to evaluate the cost and the current morbidity of the infection with MRSA in the ICU.

METHODS

In a retrospective case-control study carried out in 2004, all patients of the 6 intensive care units of a teaching hospital having developed a MRSA nosocomial infection were included. They were paired with controls on the following criteria: department, Simplified Acute Physiology Score II (SAPSII), age (+/- 5 years), type of surgery (for the surgical intensive care units). The duration of hospitalization of the paired control had to be at least equal to the time from admission to infection of the infected patient. The costs were evaluated using the following parameters: scores omega 1, 2 and 3, duration of artificial ventilation, hemodialysis, length of ICU stay, radiological procedures, surgical procedures, total antibiotic cost and other expensive drugs.

RESULTS

Twenty-one patients with MRSA infection were included. All had nosocomial pneumonia. The 21 paired patients were similar with regard to both initial criteria and sex. Hospital mortality was not different between the 2 groups (cases=8; controls=6; p=0.41), as well as median duration of hospital stay (cases=41 days; controls=43 days; p=0.9). The duration of mechanical ventilation, number of hemodialysis or hemofiltration sessions, number of radiological procedures were similar in both groups. The total omega score was not significantly different between cases (median 435; IQR: 218-579) and controls (median 281, IQR: 231-419; p=0.55). The median duration of isolation was 12 days for cases and 0 day for controls (p=0.0007). The pharmaceutical expenditure was significantly higher in cases (median: 1414euro; IQR: 795-4349), by comparison with the controls (median: 877euro, IQR: 687-2496) (p=0.049).

CONCLUSION

In the ICU having set up a policy intended to reduce the risk of MRSA nosocomial infections, MRSA pneumonia does not seem to involve major additional morbidity, as compared to a control population matched for similar severity of illness. It increases modestly the use of the medical resources.

Overcrowding and understaffing in modern health-care systems: key determinants in meticillin-resistant Staphylococcus aureus transmission

Recent decades have seen the global emergence of meticillin-resistant Staphylococcus aureus (MRSA), causing substantial health and economic burdens on patients and health-care systems. This epidemic has occurred at the same time that policies promoting higher patient throughput in hospitals have led to many services operating at, or near, full capacity. A result has been limited ability to scale services according to fluctuations in patient admissions and available staff, and hospital overcrowding and understaffing. Overcrowding and understaffing lead to failure of MRSA control programmes via decreased health-care worker hand-hygiene compliance, increased movement of patients and staff between hospital wards, decreased levels of cohorting, and overburdening of screening and isolation facilities. In turn, a high MRSA incidence leads to increased inpatient length of stay and bed blocking, exacerbating overcrowding and leading to a vicious cycle characterised by further infection control failure. Future decision making should use epidemiological and economic evidence to evaluate the effect of systems changes on the incidence of MRSA infection and other adverse events.

5 Million Lives Campaign. Reducing methicillin-resistant Staphylococcus aureus (MRSA) infections

BACKGROUND

Hospital-acquired infections from methicillin-resistant Staphylococcus aureus (MRSA) now account for more than 60% of S. aureus infections in intensive care patients reported to the Centers for Disease Control and Prevention (CDC). Media stories have raised the profile of this problem, and several states have moved toward legislative action regarding screening of hospital patients or mandatory reporting of infections. Guidelines from clinical expert organizations, including the CDC, the Association for Professionals in Infection Control and Epidemiology (APIC), and the Society for Healthcare Epidemiology of America (SHEA), recommend the use of basic prevention practices to avoid transmission in the hospital setting, yet concerns persist that compliance with these practices is neither consistent nor reliable.

INTERVENTION

The campaign's MRSA intervention recommends five key components of care. These are not intended to be an all-inclusive list but rather have been recommended by experts as the minimum necessary components: (1) hand hygiene, (2) decontamination of the environment and equipment, (3) active surveillance, (4) contact precautions for infected and colonized patients, and (5) device bundles (central line bundle and ventilator bundle).

CONCLUSION

The IHI's 5 Million Lives Campaign considers all hospital-acquired infections as harm to patients, and reduction of MRSA is one of the areas of focus.

Burden of methicillin-resistant Staphylococcus aureus: focus on clinical and economic outcomes

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a major public concern. Hospital-acquired MRSA rates have steadily increased over the past 25 years, and the bacterial strain is making inroads to the community. The morbidity and mortality burden of MRSA infection is compounded by delayed or inappropriate antibiotic treatment, taking a toll on health care resources that are already stretched thin. Vancomycin has historically been the drug of choice for this pathogen because its broad spectrum can address the multidrug resistance of most MRSA infections. Despite its sustained in vitro microbiologic inhibitory activity, researchers are beginning to question the continued utility of vancomycin for MRSA infections. Evidence against vancomycin is most notable with regard to nosocomial pneumonia and skin and soft tissue infections. In addition, because vancomycin must be administered intravenously, patients typically require prolonged hospitalization, which further increases the cost of MRSA treatment and exposes patients to additional nosocomial infections. Recent studies have shown that antibiotics with good bioavailability, such as linezolid, can be given orally to facilitate early hospital discharge, thus alleviating the economic burden of MRSA infections. Several agents have been developed over the past decade that have excellent in vitro activity against MRSA. Further studies are needed to determine if these drugs can better eradicate MRSA than vancomycin and remedy the adverse outcomes frequently observed with this organism.

Selective use of intranasal mupirocin and chlorhexidine bathing and the incidence of methicillin-resistant Staphylococcus aureus colonization and infection among intensive care unit patients

OBJECTIVE

To determine whether the use of chlorhexidine bathing and intranasal mupirocin therapy among patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) would decrease the incidence of MRSA colonization and infection among intensive care unit (ICU) patients.

METHODS

After a 9-month baseline period (January 13, 2003, through October 12, 2003) during which all incident cases of MRSA colonization or infection were identified through the use of active-surveillance cultures in a combined medical-coronary ICU, all patients colonized with MRSA were treated with intranasal mupirocin and underwent daily chlorhexidine bathing.

RESULTS

After the intervention, incident cases of MRSA colonization or infection decreased 52% (incidence density, 8.45 vs 4.05 cases per 1,000 patient-days; P=.048). All MRSA isolates remained susceptible to chlorhexidine; the overall rate of mupirocin resistance was low (4.4%) among isolates identified by surveillance cultures and did not increase during the intervention period.

CONCLUSIONS

We conclude that the selective use of intranasal mupirocin and daily chlorhexidine bathing for patients colonized with MRSA reduced the incidence of MRSA colonization and infection and contributed to reductions identified by active-surveillance cultures. This finding suggests that additional strategies to reduce the incidence of MRSA infection and colonization--beyond expanded surveillance--may be needed.

Methicillin-resistant Staphylococcus aureus (MRSA) detection: comparison of two molecular methods (IDI-MRSA PCR assay and GenoType MRSA Direct PCR assay) with three selective MRSA agars (MRSA ID, MRSASelect, and CHROMagar MRSA) for use with infection-control swabs

Methicillin-resistant Staphylococcus aureus (MRSA) is an increasing problem. Rapid detection of MRSA-colonized patients has the potential to limit spread of the organism. We evaluated the sensitivities and specificities of MRSA detection by two molecular methods (IDI-MRSA PCR assay and GenoType MRSA Direct PCR assay) and three selective MRSA agars (MRSA ID, MRSASelect, and CHROMagar MRSA), using 205 (101 nasal, 52 groin, and 52 axillary samples) samples from consecutive known MRSA-infected and/or -colonized patients. All detection methods had higher MRSA detection rates for nasal swabs than for axillary and groin swabs. Detection of MRSA by IDI-MRSA was the most sensitive method, independent of the site (94% for nasal samples, 80% for nonnasal samples, and 90% overall). The sensitivities of the GenoType MRSA Direct assay and the MRSA ID, MRSASelect, and CHROMagar MRSA agars with nasal swabs were 70%, 72%, 68%, and 75%, respectively. All detection methods had high specificities (95 to 99%), independent of the swab site. Extended incubation for a further 24 h with selective MRSA agars increased the detection of MRSA, with a corresponding decline in specificity secondary to a significant increase in false-positive results. There was a noticeable difference in test performance of the GenoType MRSA Direct assay in detection of MRSA (28/38 samples [74%]) compared with detection of nonmultiresistant MRSA (17/31 samples [55%]) (susceptible to two or more non-beta-lactam antibiotics). This was not observed with selective MRSA agar plates or IDI-MRSA. Although it is more expensive, in addition to rapid turnaround times of 2 to 4 h, IDI-MRSA offers greater detection of MRSA colonization, independent of the swab site, than do conventional selective agars and GenoType MRSA Direct.

National guidelines for the control and prevention of methicillin-resistant Staphylococcus aureus--what do they tell us?

Guidelines to control and prevent methicillin-resistant Staphylococcus aureus (MRSA) infection are available in many countries. Infection control and prevention teams determine local strategies using such national guidelines, but not all guidelines involve a rigorous assessment of the literature to determine the strength of the recommendations. Available guidelines drafted by national agencies or prominent professional organisations in Germany, New Zealand, North America, The Netherlands, Ireland and the UK were reviewed. Significant literature reviews were a component of guidelines from the UK and North America. Recommendations were not graded on the strength of the evidence in guidelines from New Zealand and The Netherlands. The Netherlands, a country with a very low prevalence of MRSA, had the simplest set of guidelines. Few of the recommendations in any of the guidelines achieved the highest grading, i.e., based on well-designed, experimental, clinical or epidemiological studies, even though the logic of the proposed measures is clear. The onset of community-acquired MRSA is reflected in the recent publication of guidelines from North America. New developments, such as rapid testing and mathematical modelling, are of importance in helping to control MRSA in settings of both low and high endemicity. National guidelines are increasingly evidence-based, although good scientific studies concerning some aspects of MRSA control are lacking. However, general principles, e.g., early detection and isolation, are recommended by all guidelines. There is still a role for consensus and the opinion of experts in devising national guidelines.

Costs of an outbreak of meticillin-resistant Staphylococcus aureus

An outbreak of meticillin-resistant Staphylococcus aureus (MRSA) occurred in surgical and internal medicine units of a 1752-bed Finnish tertiary care hospital during 2003-2004. In order to analyse the costs of this 14-month outbreak, patients were categorized as follows: patients with MRSA infections; patients with MRSA colonization; patients exposed to MRSA but whose MRSA status remained inconclusive; and exposed patients who were negative for MRSA. We reviewed a sample of patients' charts to determine the types of clinical infections and interviewed staff about the practical implementation of control measures. The number of patients and patient-days involved in the outbreak were identified from the hospital's databases, with the administrative database supplying unit costs of work and materials. Loss of income due to closed beds was analysed. A total of 266 MRSA-positive patients (114 with infections and 152 colonized) and 797 patients exposed to MRSA were identified (11,744 contact isolation days). There were 1240 patients negative after screening (9880 contact isolation days). Total additional costs of MRSA were 386,062 euro (70% for screening and 25% for contact isolation). Costs due to meticillin resistance in treatment of MRSA infections were 16,000 euro. The income loss for this hospital due to closed beds was 1,183,808 euro. The high cost of MRSA screening underlines the importance of appropriate screening methods. Our model of analysing costs might be useful for other hospitals after adapting variables such as local control measures.

Clinical outcome and costs of nosocomial and community-acquired Staphylococcus aureus bloodstream infection in haemodialysis patients

The main aim of this study was to evaluate the clinical outcome and costs of nosocomial and community-acquired methicillin-susceptible Staphylococcus aureus (MSSA) or methicillin-resistant S. aureus (MRSA) bloodstream infection (BSI) in patients undergoing haemodialysis. A multicentre retrospective study was conducted that included 109 patients with end-stage renal disease and S. aureus BSI who were hospitalised in three German centres between 1999 and 2005. Nosocomial and community-acquired infections were analysed separately with regard to costs and outcome. Forty-nine (45%) patients had nosocomial infection. Compared to patients with community-acquired infection, these patients were more likely to have had BSI caused by MRSA (40.8% vs. 13.3%, p <0.05). BSI was the initial reason for admission for 33 (55%) patients who had community-acquired infection. The mean length of hospitalisation was 24 days for patients with community-acquired infection and 51 days for patients with nosocomial infection (p <0.05). Costs per treatment episode were 20,024 Euros for nosocomial infection vs. 9554 Euros for community-acquired infection (p <0.05). The average treatment costs for patients with MSSA BSI were <50% of those for patients with MRSA BSI (10,573 vs. 24,931 Euros, p <0.05). S. aureus BSI is an underlying cause of substantial health risk and high morbidity among the haemodialysis-dependent population, who are already at high-risk for other reasons. This study also highlighted differences according to the source of BSI, including costs arising from hospitalisation and treatment.

Impact and cost of infection control measures to reduce nosocomial transmission of extended-spectrum beta-lactamase-producing organisms in a non-outbreak setting

We evaluated the impact of infection control interventions to reduce nosocomial extended-spectrum beta-lactamase (ESBL) transmission in a non-outbreak setting. This study was conducted at a tertiary 1200-bed hospital in Canada. The incidence of ESBLs was based on recovery of clinical isolates and assessed prospectively from 1999 to 2005. The incidence increased significantly from 0.28 to 0.67 per 1000 admissions during this period (P<0.001), reflecting an increase in the regional ESBL incidence from 1.32 to 9.28 per 100 000 population (P<0.001). Despite this increase, nosocomial ESBL rates increased only marginally, suggesting that infection control measures had an impact on nosocomial transmission. Infection control measures consisted of isolating all ESBL patients, as well as implementing the use of contact precautions for those with a high risk for transmission. The cost of these measures was CN$138 046.00 per year and CN$3191.83 per case admitted. A combination of control measures including active surveillance cultures, contact precautions for all colonized or infected patients and antimicrobial stewardship is required to significantly reduce the incidence of ESBLs.

Impact of a methicillin-resistant Staphylococcus aureus active surveillance program on contact precaution utilization in a surgical intensive care unit

OBJECTIVE

To determine the impact of an active surveillance for methicillin-resistant Staphylococcus aureus (MRSA) on contact precaution utilization, as measured by additional number of contact precaution days attributable to the active surveillance program.

DESIGN

Prospective cohort study.

SETTING

Twenty-four-bed surgical intensive care unit (ICU).

PATIENTS

All patients admitted to the surgical ICU.

INTERVENTIONS

Nasal cultures for MRSA were performed at admission to a surgical ICU for 19 months. Patients admitted>48 hrs also received weekly and discharge nasal cultures.

MEASUREMENTS AND MAIN RESULTS

Clinical data, including start date and initial indication for contact precautions, were prospectively collected. Of 1,893 admissions, 253 (13%) were found to be MRSA-positive during their ICU stay. One hundred forty-six (58%) were identified by nasal culture alone. Compared with the first 10 months of study, the prevalence of MRSA on admission to the ICU during the last 9 months of the study period significantly increased (7.2% vs. 11.4%, p<.001). Acquisition of MRSA by noncolonized patients remained constant between the first 10 months and last 9 months of study (7.0 vs. 5.5 cases per 1000 patient days, p=.29). Two hundred fourteen (6%) of 3461 total contact precaution days in the ICU were attributable to MRSA active surveillance. In sensitivity analyses, the implementation of rapid, same-day results for MRSA active surveillance would increase contact precaution days by 15% compared with no surveillance. If the total number of vancomycin-resistant enterococci patients in the ICU were reduced by 50%, the contact precaution days attributable to active surveillance would increase to 9%.

CONCLUSIONS

MRSA active surveillance increased total contact precaution days in this ICU by 6% yet detected 58% of MRSA cases that would have been otherwise missed. Despite an increasing prevalence of MRSA on admission to the ICU, the acquisition rate has remained constant.

Randomized Controlled Trial of Chlorhexidine Gluconate for Washing, Intranasal Mupirocin, and Rifampin and Doxycycline Versus No Treatment for the Eradication of Methicillin-Resistant Staphylococcus aureus Colonization

BACKGROUND

Eradication of methicillin-resistant Staphylococcus aureus (MRSA) carriage may reduce the risk of MRSA infection and prevent transmission of the organism to other patients.

METHODS

To determine the efficacy of decolonization therapy, patients colonized with MRSA were randomized (3:1 allocation) to receive treatment (2% chlorhexidine gluconate washes and 2% mupirocin ointment intranasally, with oral rifampin and doxycycline for 7 days), or no treatment. Follow-up samples for MRSA culture were obtained from the nares, perineum, skin lesions, and catheter exit sites monthly for up to 8 months. The primary outcome measure was detection of MRSA at 3 months of follow-up. Univariate and multivariable analyses were performed to identify variables associated with treatment failure.

RESULTS

Of 146 patients enrolled in the study, 112 patients (87 treated; 25 not treated) were followed up for at least 3 months. At 3 months of follow-up, 64 (74%) of those treated had culture results negative for MRSA, compared with 8 (32%) of those not treated (P=.0001). This difference remained significant at 8 months of follow-up, at which time, 54% of those treated had culture results negative for MRSA (chi2=64.4; P<.0001, by log-rank test). The results of the multivariable analysis indicated that having a mupirocin-resistant isolate at baseline was associated with treatment failure (relative risk, 9.4; 95% confidence interval, 2.8-31.9; P=.0003), whereas decolonization therapy was protective (relative risk, 0.1; 95% confidence interval, 0.04-0.4; P=.0002). Mupirocin resistance emerged in only 5% of follow-up isolates.

CONCLUSIONS

Treatment with topical mupirocin, chlorhexidine gluconate washes, oral rifampin, and doxycycline for 7 days was safe and effective in eradicating MRSA colonization in hospitalized patients for at least 3 months.

Epidemiology and economic impact of meticillin-resistant Staphylococcus aureus: review and analysis of the literature

In the past 2 decades, meticillin-resistant Staphylococcus aureus (MRSA) has become an increasingly prevalent problem in healthcare, both in acute care institutions and in the community. MRSA is associated with worse outcomes and higher costs for care than meticillin sensitive S. aureus (MSSA). MRSA is a particular problem in several conditions, including hospital-acquired pneumonia (including ventilator-associated pneumonia), skin and soft tissue infections, and diabetic foot infections. Hospitalisation costs associated with MRSA infection are substantially greater than those associated with MSSA infection, and MRSA has wider economic effects that involve indirect costs to the patient and to society. In several countries, infection control programmes have shown potential economic benefits, as savings accruing from strict and effective control have been shown to outweigh the cost of policy implementation. Standard therapy is based on glycopeptide treatment, usually with vancomycin, although resistance to this agent has emerged. Alternative available treatments for MRSA include teicoplanin, tigecycline, daptomycin, quinupristin-dalfopristin and the oxazolidinone, linezolid, which has a higher acquisition cost than vancomycin but is available as intravenous and oral formulations. Despite some limitations of analyses to date, linezolid has been shown to be cost effective in the treatment of MRSA and appears to be related, in part, to the drug's potential for facilitating earlier discharge from hospital. Current opinion favours rational prescribing to maximise therapeutic benefit and minimise the risk of further antibacterial resistance.

Methicillin-resistant Staphylococcus aureus: A public health issue with economic consequences

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) has become endemic worldwide in hospitals, and community-associated MRSA is spreading into the community at large.

OBJECTIVES

To estimate the current cost of MRSA in Canada and to assess the magnitude of this public health issue.

METHODS

An extensive review of the literature was conducted to gather epidemiology, health care resource utilization and cost data for MRSA in Canadian settings. The current MRSA burden was estimated using available cost data and the most recent epidemiology data.

RESULTS

The rate of MRSA in Canadian hospitals increased from 0.46 to 5.90 per 1000 admissions between 1995 and 2004, while community-associated MRSA continued to spread into the community. Patients harbouring MRSA required prolonged hospitalization (average 26 days of isolation per patient), special control measures, expensive treatments and extensive surveillance. Total cost per infected MRSA patient averaged $12,216, with hospitalization being the major cost driver (81%), followed by barrier precautions (13%), antimicrobial therapy (4%) and laboratory investigations (2%). The most recent epidemiological data, combined with available cost data, suggest that direct health care cost attributable to MRSA in Canada, including cost for management of MRSA-infected and-colonized patients and MRSA infrastructure, averaged $82 million in 2004 and could reach $129 million in 2010.

CONCLUSION

MRSA is a costly public health issue that needs to be tackled if the growing burden of this disease in Canadian hospitals and in the community is to be limited.

Evaluation of the IDI-MRSA assay for detection of methicillin-resistant staphylococcus aureus from nasal and rectal specimens pooled in a selective broth

Rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) by PCR can be performed directly from nasal specimens with the IDI-MRSA assay. To improve the efficiency of screening, we evaluated the performance of the IDI-MRSA assay for the detection of MRSA from pooled and unpooled specimens cultured in a selective broth. Of the 287 specimens evaluated, 71 were culture and PCR positive, 203 were culture and PCR negative, 3 were culture positive and PCR negative, 8 were culture negative and PCR positive, and 2 remained inhibited. A methicillin-susceptible Staphylococcus aureus isolate was recovered from five of the eight specimens with false-positive PCR results. Compared to the results of culture, the sensitivity, specificity, and positive and negative [corrected] predictive values of the IDI-MRSA assay for detection of MRSA from broth were 96%, 96%, 90%, and 98%, respectively. Following implementation of the IDI-MRSA assay, PCR-positive broths were subcultured for evaluation of assay performance. Of the 298 IDI-MRSA assay-positive broths, the results for 103 could not be confirmed by culture. A methicillin-susceptible S. aureus (MSSA) isolate was recovered from 77 of these 103 broths. Repeat testing by the IDI-MRSA assay directly with the MSSA isolates confirmed the original positive PCR result. The positive predictive value of the IDI-MRSA assay fell from 90% during the evaluation phase to 65% postimplementation. The IDI-MRSA assay performed well for the detection of MRSA from a selective broth compared to the performance of the detection of MRSA from culture. However, because of the burden associated with implementation of infection control precautions, cultures remain essential in confirming positive IDI-MRSA results.

[Control of methicillin-resistant S. aureus by active surveillance. Results of a workshop held by the Deutsche Gesellschaft für Hygiene und Mikrobiologie]

In Germany, methicillin-resistant S. aureus (MRSA) is increasing continuously. To control the spread of MRSA, active surveillance and admission screening are recommended. In most cases, screening cultures of patients at risk for MRSA will be sufficient. Screening of all patients admitted to an ICU is cost-effective when the incidence of MRSA and nosocomial MRSA infections is high (>2 cases/100 patients and 0.3 MRSA infections/100 patients, respectively): Under these circumstances, a decrease in the incidence of nosocomial MRSA infections of 50% leads to cost-effectiveness at costs of 16 Euro/sample (including subsequent costs). If the incidence of nosocomial MRSA infections decreases by 75%, costs of 24 Euro/sample (including subsequent costs) are cost-effective. If the incidence of MRSA is high, screening by PCR may be cost-effective for patients at high risk for MRSA, especially if they are isolated prophylactically. Recently, PCR methods have been developed which allow the specific identification of MRSA even from nasal swabs.

Evaluation of a new chromogenic medium, MRSA select, for detection of methicillin-resistant Staphylococcus aureus

We compared MRSA Select to mannitol-salt agar with 8 microg/ml cefoxitin for the detection of methicillin-resistant Staphylococcus aureus (MRSA) from 6,199 clinical samples submitted for MRSA screening. The sensitivities and specificities of MRSA Select and mannitol-salt agar with cefoxitin were 98% and 92% versus 90% and 78%, respectively (P<0.0001). Most (96%) MRSA were detected after overnight incubation using MRSA Select.

Comparative cost of selective screening to prevent transmission of methicillin-resistant Staphylococcus aureus (MRSA), compared with the attributable costs of MRSA infection

The annual cost of a screening program to detect methicillin-resistant Staphylococcus aureus (MRSA) in a teaching hospital in Spain was 10,261 Euro. The average cost per MRSA infection was 2,730 Euro; therefore, the cost of the program would be covered if it only prevented 4 infections per year (11% of the total number of MRSA infections at our hospital).

Comorbidity risk-adjustment measures were developed and validated for studies of antibiotic-resistant infections

OBJECTIVES

Comorbidities are often included in risk-factor models for nosocomial antibiotic-resistant bacterial infections, and aggregate comorbidity measures are valuable because they allow one variable to represent many. This study aimed to develop new aggregate comorbidity measures based upon the Chronic Disease Score (CDS) for assessing the comorbidity-attributable risk of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) nosocomial infections.

STUDY DESIGN AND SETTING

For each outcome, two retrospective cohort studies of hospitalized patients were conducted. Outcomes were a first MRSA or VRE positive clinical culture obtained 48 hours or more postadmission. Each cohort was divided into development (July 1998-2001) and validation (August 2001-2003) samples. New comorbidity measures were created for MRSA (CDS-MRSA), VRE (CDS-VRE), or any nosocomial infection outcome (CDS-ID) using logistic regression and subsequently validated. Model discrimination was measured using the c-statistic.

RESULTS

Discrimination of the CDS-MRSA (c=0.60), CDS-VRE (c=0.65), and CDS-ID (MRSA: c=0.57; VRE: c=0.64) was greater than that of the original CDS (MRSA: c=0.52; VRE: c=0.57).

CONCLUSION

The CDS-MRSA, CDS-VRE, and CDS-ID are new infectious disease specific comorbidity risk-adjustment measures that will be useful for the quality of future epidemiologic studies of MRSA, VRE, and other infectious diseases.

Enhanced surveillance of meticillin-resistant Staphylococcus aureus bacteraemia in a London teaching hospital

In 2001, the UK Department of Health introduced mandatory surveillance of meticillin-resistant Staphylococcus aureus (MRSA) bacteraemias (blood-culture-positive episodes) in English hospitals. We performed enhanced surveillance in their hospital between April 2001 and March 2003 to determine the epidemiology of MRSA bacteraemia across different specialities. There were 267 MRSA-blood-culture-positive episodes, giving a rate of 0.37 per 1000 occupied bed-days (OBD). Thirty-three (12.4%) episodes were false positives due to contaminants and 15 (5.6%) originated in the community or at another institution. Thirty-one (11.6%) episodes were in outpatients or occurred after recent discharge and were designated 'hospital associated'. The remaining 188 cases were clinically significant hospital-acquired episodes in inpatients, with a rate of 0.26 per 1000 OBDs. The highest rates were in the intensive therapy unit (ITU; 2.74 per 1000 OBDs) and the high-dependency unit (HDU; 1.68 per 1000 OBDs). Fifty-five non-ITU, non-HDU episodes occurred in patients who had been discharged from ITU or HDU prior to the development of bacteraemia but during the same admission. The number of MRSA bacteraemias related to ITU/HDU suggests that these wards may be hubs of MRSA infection. Haematology, oncology and renal (HOR) patients had the greatest number of hospital-associated episodes. The most common source of MRSA bacteraemia was a vascular access device (VAD) (108 episodes, 57%, 64% of which were central lines). The high bacteraemia rates in ITU, HDU and HOR patients were associated with high usage of VADs. The majority of episodes occurred in patients who were newly colonized with MRSA after admission. Thus, in this hospital, VADs and stays in ITU or HDU are important risk factors for bacteraemia, and VAD care and prevention of cross-infection are priorities for intervention. We recommend that the mandatory national surveillance scheme should collect additional data on MRSA bacteraemia to provide information for a national strategy for MRSA control and to allow appropriate comparison between institutions.

Physical Plant Design and Engineering Controls to Reduce Hospital-acquired Infections

The importance of the environment as a reservoir for microorganisms implicated in disease transmission in the hospital setting has been increasingly recognized, especially with respect to dialysis units, ventilation in specialized areas, and the proper use of disinfectants (1). Inherent within the environmental setting is the importance of physical plant design. Several studies have underscored the importance of optimizing design standards to maximize patient and health care worker (HCW) safety, including the prevention of hospital-acquired infections in patients (2-6). Ulrich et al (7) recently completed an evidence-based review, entitled'The role of the physical environment in the hospital of the 21st century: A once-in-a-lifetime opportunity', for the Center for Health Design in California (USA), which was funded by the Robert Wood Johnson Foundation. Ulrich and colleagues identified over 600 studies that examined the hospital environment and its effects on staff effectiveness, patient safety, patient and family stress, quality and costs. They suggested that one of the important elements in improving patient safety is the reduction of the risk of hospital-acquired infections through improved facility design.

Guidelines for the control and prevention of meticillin-resistant Staphylococcus aureus (MRSA) in healthcare facilities

Meticillin-resistant Staphylococcus aureus (MRSA) remains endemic in many UK hospitals. Specific guidelines for control and prevention are justified because MRSA causes serious illness and results in significant additional healthcare costs. Guidelines were drafted by a multi-disciplinary group and these have been finalised following extensive consultation. The recommendations have been graded according to the strength of evidence. Surveillance of MRSA should be undertaken in a systematic way and should be fed back routinely to healthcare staff. The inappropriate or unnecessary use of antibiotics should be avoided, and this will also reduce the likelihood of the emergence and spread of strains with reduced susceptibility to glycopeptides, i.e. vancomycin-intermediate S. aureus/glycopeptide-intermediate S. aureus (VISA/GISA) and vancomycin-resistant S. aureus (VRSA). Screening for MRSA carriage in selected patients and clinical areas should be performed according to locally agreed criteria based upon assessment of the risks and consequences of transmission and infection. Nasal and skin decolonization should be considered in certain categories of patients. The general principles of infection control should be adopted for patients with MRSA, including patient isolation and the appropriate cleaning and decontamination of clinical areas. Inadequate staffing, especially amongst nurses, contributes to the increased prevalence of MRSA. Laboratories should notify the relevant national authorities if VISA/GISA or VRSA isolates are identified.

Is antibiotic resistance a problem? A practical guide for hospital clinicians

Antibiotic resistance is an important concern for patients, physicians, healthcare managers, and policymakers. Inappropriate antimicrobial prescribing fuels the evolution of resistance, while poor basic hygiene facilitates the spread of resistant microbes between patients and healthcare staff. The development of infection with a resistant pathogen may lead to poorer health and economic outcomes. The problem for the frontline clinician, however, is how to balance the responsibility of prudent prescribing with the risk of sub-optimally treating a patient who may be infected with a resistant pathogen. This article discusses how hospital physicians can use severity and risk factor assessment, and knowledge of local microbial epidemiology, to guide empiric antibiotic prescribing. Most patients hospitalised with a community acquired bacterial infection in the UK can still be managed with a traditional first line antibiotic(s). In contrast, regimens that account for resistance are often required in patients with hospital acquired infections, particularly if the patient is critically ill.

Understanding the rise of the superbug: investigation of the evolution and genomic variation of Staphylococcus aureus

The bacterium Staphylococcus aureus is a common cause of human infection, and it is becoming increasingly virulent and resistant to antibiotics. Our understanding of the evolution of this species has been greatly enhanced by the recent sequencing of the genomes of seven strains of S. aureus. Comparative genomic analysis allows us to identify variation in the chromosomes and understand the mechanisms by which this versatile bacterium has accumulated diversity within its genome structure.

Economic burden associated with multi-resistant Gram-negative organisms compared with that for methicillin-resistant Staphylococcus aureus in a university teaching hospital

The aim of this study was to investigate the hospital costs of patients with multi-drug-resistant Gram-negative bacilli (MR-GNB) compared with those for patients with methicillin-resistant Staphylococcus aureus (MRSA), using the Austrian performance-related hospital financing system (LKF). The study was performed retrospectively at Vienna General Hospital, a 2,160-bed university teaching hospital, from January to June 2002. There were 99 patients in the MR-GNB group (median age 58 years) and 74 patients in the MRSA group (median age 60 years). More patients in the MR-GNB group (59 patients, 60%) were treated in the intensive care unit compared with patients in the MRSA group (25 patients, 34%) (P<0.01). The median hospital stay (42 and 37 days, respectively) and mortality (18 and nine deaths, respectively) of the two groups were similar. The total hospital cost for patients in the MR-GNB group was higher [4 915 712 LKF credit points (median: 34,180) equivalent to 2,605,327 pounds (median: 18,115 pounds )] than that for patients in the MRSA group [2,088,904 LKF credit points (median: 12,650) equivalent to 1, 093, 906 pounds (median: 6,624 pounds)] (P<0.01). This study is limited by being retrospective and having charge-based costings. However, it suggests that the hospital costs of patients with MR-GNB are substantial and may be greater than those of patients with MRSA.

Cost analysis of a hospital-wide selective screening programme for methicillin-resistant Staphylococcus aureus (MRSA) carriers in the context of diagnosis related groups (DRG) payment

The costs of a hospital-wide selective screening programme were analysed for a period of 19 months. During this time, 539 inpatients were screened, of whom 111 were MRSA-positive. Based on microbiological costs (staff and materials) and the costs of preventive contact isolation for 2 days until microbiological results were available (including material costs for medical consumable goods and the costs of additional nursing time), a total of 26,241.51 Euro was spent for the 539 patients screened. Based on cost units, the costs were 39.96 Euro for a patient found to be MRSA-negative and 82.33 Euro for a patient found to be MRSA-positive. Under the prospective diagnosis related groups (DRG) payment system in Germany, the costs of a prolonged hospital stay resulting from a hospital-acquired MRSA infection (HA-MRSA-I) are not reimbursed adequately by revenues, with a calculated average cost-revenue loss/patient with HA-MRSA-I of 5705.75 Euro. The screening programme was able to prevent 48% of predicted HA-MRSA-Is (35.2 patients with infection), thereby saving a predicted 200,782.73 Euro. After subtracting the screening costs, there was a net saving of 110,236.56 Euro annually. A sensitivity analysis of the break-even points for different screening frequencies and different MRSA incidence rates indicated that the screening programme became cost-effective at a low MRSA incidence rate, meaning that it can be recommended for most hospitals with an MRSA problem.