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Biomedical subjects

A E Simor

Publications and source records attributed to A E Simor.

At least 19 recordsLinked to original sources
PubMed2001

The evolution of methicillin-resistant Staphylococcus aureus in Canadian hospitals: 5 years of national surveillance.

BACKGROUND: To better understand the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Canadian hospitals, surveillance has been conducted in sentinel hospitals across the country since 1995. We report the results of the first 5 years of the program. METHODS: For each newly identified inpatient with MRSA, medical records were reviewed for demographic and clinical data. Isolates were subjected to susceptibility testing and molecular typing by pulsed-field gel electrophoresis. RESULTS: A total of 4507 patients infected or colonized with MRSA were identified between January 1995 and December 1999. The rate of MRSA increased each year from a mean of 0.95 per 100 S. aureus isolates in 1995 to 5.97 per 100 isolates in 1999 (0.46 per 1000 admissions in 1995 to 4.12 per 1000 admissions in 1999) (p < 0.05). Most of the increase in MRSA occurred in Ontario, Quebec and the western provinces. Of the 3009 cases for which the site of MRSA acquisition could be determined, 86% were acquired in a hospital, 8% were acquired in a long-term care facility and 6% were acquired in the community. A total of 1603 patients (36%) were infected with MRSA. The most common sites of infection were skin or soft tissue (25% of MRSA infections), pulmonary tissues (24%) and surgical sites (23%); 13% of the patients were bacteremic. An epidemiologic link with a previously identified MRSA patient was suspected in 53% of the cases. Molecular typing indicated that most (81%) of the isolates could be classified as related to 1 of the 4 Canadian epidemic strains of MRSA. INTERPRETATION: There has been a significant increase in the rate of isolating MRSA in many Canadian hospitals, related to the transmission of a relatively small number of MRSA strains.

Adolescent↗
PubMed2001

Antibiotic use in Ontario facilities that provide chronic care.

OBJECTIVE: To determine the incidence and variability of antibiotic use in facilities which provide chronic care and to determine how often clinical criteria for infection are met when antibiotics are prescribed in these facilities. DESIGN: A prospective, 12-month, observational cohort study. SETTING: Twenty-two facilities which provide chronic care in southwestern Ontario. PARTICIPANTS: Patients who were treated with systemic antibiotics over the study period. MEASUREMENTS: Characteristics of antibiotic prescriptions (name, dose, duration, and indication) and clinical features of randomly selected patients who were treated with antibiotics. RESULTS: A total of 9,373 courses of antibiotics were prescribed for 2,408 patients (66% of all patients in study facilities). The incidence of antibiotic prescriptions in the facilities ranged from 2.9 to 13.9 antibiotic courses per 1,000 patient-days. Thirty-six percent of antibiotics were prescribed for respiratory tract infections, 33% for urinary infections, and 13% for skin and soft tissue infections. Standardized surveillance definitions of infection were met in 49% of the 1,602 randomly selected patients who were prescribed antibiotics. Diagnostic criteria for respiratory, urinary, and skin infection were met in 58%, 28%, and 65% of prescriptions, respectively. One third of antibiotic prescriptions for a urinary indication were for asymptomatic bacteriuria. Adverse reactions were noted in 6% of prescriptions for respiratory and urinary infections and 4% of prescriptions for skin infection. CONCLUSIONS: Antibiotic use is frequent and highly variable amongst patients who receive chronic care. Reducing antibiotic prescriptions for asymptomatic bacteriuria represents an important way to optimize antibiotic use in this population.

Aged↗
PubMed2001

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

OBJECTIVES: To determine the costs associated with the management of hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA), and to estimate the economic burden associated with MRSA in Canadian hospitals. DESIGN: Patient-specific costs were used to determine the attributable cost of MRSA associated with excess hospitalization and concurrent treatment. Excess hospitalization for infected patients was identified using the Appropriateness Evaluation Protocol, a criterion-based chart review process to determine the need for each day of hospitalization. Concurrent treatment costs were identified through chart review for days in isolation, antimicrobial therapy, and MRSA screening tests. The economic burden to Canadian hospitals was estimated based on 3,167,521 hospital discharges for 1996 and 1997 and an incidence of 4.12 MRSA cases per 1,000 admissions. SETTING: A tertiary-care, university-affiliated teaching hospital in Toronto, Ontario, Canada. PATIENTS: Inpatients with at least one culture yielding MRSA between April 1996 and March 1998. RESULTS: A total of 20 patients with MRSA infections and 79 colonized patients (with 94 admissions) were identified. This represented a rate of 2.9 MRSA cases per 1,000 admissions. The mean number of additional hospital days attributable to MRSA infection was 14, with 11 admissions having at least 1 attributable day. The total attributable cost to treat MRSA infections was $287,200, or $14,360 per patient The cost for isolation and management of colonized patients was $128,095, or $1,363 per admission. Costs for MRSA screening in the hospital were $109,813. Assuming an infection rate of 10% to 20%, we determined the costs associated with MRSA in Canadian hospitals to be $42 million to $59 million annually. CONCLUSIONS: These results indicate that there is a substantial economic burden associated with MRSA in Canadian hospitals. These costs will continue to rise if the incidence of MRSA increases further.

Cost of Illness↗
PubMed2001

Development of minimum criteria for the initiation of antibiotics in residents of long-term-care facilities: results of a consensus conference.

Establishing a clinical diagnosis of infection in residents of long-term-care facilities (LTCFs) is difficult. As a result, deciding when to initiate antibiotics can be particularly challenging. This article describes the establishment of minimum criteria for the initiation of antibiotics in residents of LTCFs. Experts in this area were invited to participate in a consensus conference. Using a modified delphi approach, a questionnaire and selected relevant articles were sent to participants who were asked to rank individual signs and symptoms with respect to their relative importance. Using the results of the weighting by participants, a modification of the nominal group process was used to achieve consensus. Criteria for initiating antibiotics for skin and soft-tissue infections, respiratory infections, urinary infections, and fever where the focus of infection is unknown were developed.

Aged↗
PubMed2001

The role of the laboratory in infection prevention and control programs in long-term-care facilities for the elderly.

Hospital infection prevention and control programs rely extensively on diagnostic microbiology laboratory testing. However, specimens for microbiological evaluation are less likely to be obtained from elderly residents of long-term-care facilities (LTCFs). In this article, issues regarding laboratory utilization and the potential role of the microbiology laboratory in infection prevention and control programs in LTCFs are reviewed. The role of the laboratory in infection surveillance, in the management of antimicrobial resistance, and in outbreak investigation are highlighted.

Aged↗
PubMed2001

Evaluation of a latex agglutination test (MRSA-Screen) for detection of oxacillin resistance in coagulase-negative Staphylococci.

The MRSA-Screen (Denka-Seiken, Tokyo, Japan) latex agglutination test was evaluated for its ability to detect PBP 2a from 200 clinical isolates of coagulase-negative staphylococci (CoNS; 84 mecA-positive strains and 116 mecA-negative strains) consisting of 108 Staphylococcus epidermidis, 37 S. saprophyticus, 15 S. haemolyticus, 11 S. hominis, 10 S. capitis, 10 S. warneri, and 3 S. lugdunensis species as well as 6 other species of CoNS. The assay was compared with susceptibility testing with an agar screen plate with oxacillin at 6 microg/ml (OXA6), by oxacillin disk diffusion (DD), by broth microdilution (BMDIL), by the E test, and with Vitek GPS-SV and Vitek GPS-107 susceptibility cards. PCR for the detection of the mecA gene was used as the "gold standard." The sensitivities and specificities for the methods evaluated were as follows: MRSA-Screen, 100 and 100%, respectively; OXA6, 100 and 99%, respectively; DD, 98 and 62%, respectively; BMDIL, 100 and 60%, respectively; E test, 100 and 51%, respectively; Vitek GPS-SV susceptibility card, 98 and 87%, respectively; and Vitek GPS-107 susceptibility card, 100 and 61%, respectively. The MRSA-Screen test accurately and rapidly detected oxacillin resistance in CoNS.

Bacterial Proteins↗
PubMed2001

Identifying research priorities on infections in older adults: proceedings of an interdisciplinary workshop.

BACKGROUND: Infections pose a substantial burden to the health of older adults. In this report, we describe the proceedings of a workshop to formulate and prioritize research questions about infections in older adults using an interdisciplinary approach. METHODS: Researchers from four sectors (basic science, clinical sciences, health services and epidemiology/determinants of health) and representatives from various Canadian local, provincial, and federal stakeholder groups were invited to a two-day workshop. Five multi-disciplinary groups and stakeholders from each of three healthcare settings (long term, acute care and community) discussed research priorities for each of the settings. Five to ten research questions were identified for each setting. RESULTS: The research questions proposed ranged from risk factors and outcomes for different infections to the effect of nutrition on infection and the role of alternative and complementary medicine in treating infections. Health service issues included barriers to immunization, prolongation of hospital length of stay by infection, use of care paths for managing infections, and decision-making in determining the site of care for individuals with infections. Clinical questions included risk factor assessment for infection, the effectiveness of preventative strategies, and technology evaluation. Epidemiologic issues included the challenge of achieving a better understanding of respiratory infections in the community and determining the prevalence of colonization with multi-resistant bacteria. CONCLUSIONS: The questions are of direct relevance to researchers in a wide variety of fields. Bringing together a multi-disciplinary group of researchers to frame and prioritize research questions about aging is feasible, participants valued the opinions of people working in other areas.

Journal Article↗
PubMed2001

Containing methicillin-resistant S aureus. Surveillance, control, and treatment methods.

In the past two decades, the prevalence of MRSA has increased in healthcare facilities in many countries around the world. The organism, which has caused nosocomial outbreaks, also has become endemic in many hospitals and long-term care facilities. Recently, reports of community-acquired MRSA in persons without known risk factors for the organism have been increasing. Transmission occurs primarily from colonized or infected patients to others through the hands of healthcare personnel. MRSA infection may be life-threatening and cause considerable morbidity, the need for prolonged hospitalization, and increased costs. Treatment options are limited because organisms are typically resistant to multiple antibiotics, but newer agents are being developed. However, there is also reason for concern about the recent emergence of MRSA resistant to glycopeptides, such as vancomycin. Efforts to limit the spread of MRSA should include surveillance and control measures, such as adequate hand hygiene and appropriate contact isolation or barrier precautions.

Anti-Bacterial Agents↗
PubMed2001

Adherence to antibiotic guidelines for pneumonia in chronic-care facilities in Ontario.

OBJECTIVES: To evaluate adherence to antibiotic recommendations for the treatment of pneumonia in patients who receive long-term care and to assess outcomes associated with these recommendations. DESIGN: A prospective cohort study. SETTING: Twenty-two facilities that provide long-term care in southern Ontario. PARTICIPANTS: Older adults treated with antibiotics for a presumptive diagnosis of pneumonia and those with radiologically confirmed pneumonia METHODS: Over a 12-month period, older patients who were treated with antibiotics for presumptive pneumonia were prospectively identified. A random sample of these antibiotic courses (646 courses in 638 patients) was reviewed using a standardized data collection form, and demographic and clinical data were collected. Antibiotic courses were classified according to Canadian and American Thoracic Society antibiotic recommendations for pneumonia. In patients with radiologically confirmed pneumonia, the effect of adherence to these recommendations on mortality and persistence of symptoms was assessed. RESULTS: Only 27.6% (178 of 646) of antibiotic prescriptions evaluated met antibiotic recommendations for nursing-home-acquired pneumonia, and the proportion meeting these varied greatly by facility, ranging from 0% to 53% (median 31%). For patients with radiologically confirmed pneumonia, age (adjusted odds ratio [OR] 1.6, 95% confidence interval [CI] 1.0-2.4, per increase in 10 yr, p = 0.02), sex (adjusted OR 3.0, 95% CI 1.1-8.0, p = 0.03), and adherence to recommended antibiotics (OR 3.0, 95% CI 1.3-7.2, p = 0.01) were associated with death. Adherence to the recommended antibiotics was also associated with adverse reactions, which occurred in 10% of prescriptions meeting the recommendations (OR 2.4, 95% CI 1.3-4.6, p = 0.01). CONCLUSIONS: Adherence to recommended guidelines for antibiotic treatment was low and highly variable among study facilities. Use of recommended antibiotic regimens was associated with increased adverse events and worse outcomes in patients with radiologically confirmed pneumonia.

Aged↗
PubMed2000

Novel cases of blastomycosis acquired in Toronto, Ontario.

Blastomycosis a potentially fatal fungal disease, is well known from defined areas of endemicity in Ontario, primarily in the northern part of the province. We present 2 unusual cases that appear to extend the area of endemicity into urban southern Ontario, specifically Toronto. Both patients presented to a dermatology clinic with skin lesions. Chest radiography, history and general physical evaluation indicated no disease at other body sites. Both cases appeared to represent "inoculation blastomycosis" connected with minor gardening injuries and a cat scratch respectively. Atypical dissemination could not be completely excluded in either case. Neither patient had travelled recently to a known area of high endemicity for blastomycosis, nor had the cat that was involved in one of the cases. Physicians must become aware that blastomycosis may mimic other diseases, including dermal infections, and may occur in patients whose travel histories would not normally suggest this infection.

Adult↗
PubMed2000

The role of DNA amplification technology in the diagnosis of infectious diseases.

Nucleic acid amplification and detection methods developed in the past decade are useful for the diagnosis and management of a variety of infectious diseases. The most widely used of these methods is the polymerase chain reaction (PCR). PCR assays can detect rapidly and accurately the presence of fastidious and slow-growing microorganisms, such as Chlamydia, mycoplasmas, mycobacteria, herpesviruses and enteroviruses, directly from clinical specimens. Commercial PCR assays for the diagnosis of tuberculosis and genital C. trachomatis infection are now routinely used in many diagnostic laboratories. Assays have also been developed that can detect antimicrobial resistance and are used to identify the cause of infection by organisms that cannot be cultivated. The value of viral load measurement by nucleic acid amplification in the management of patients with HIV infection or hepatitis C has also been well established. However, evaluations of this technology for rapid microbial diagnosis have generally been limited by small samples, and the cost of these assays may be as high as Can$125 per test. As nucleic acid amplification methods continue to evolve, their role in the diagnosis and management of patients with infectious diseases and their impact on clinical outcomes will become better defined.

Communicable Diseases↗
PubMed2000

Why are antibiotics prescribed for asymptomatic bacteriuria in institutionalized elderly people? A qualitative study of physicians' and nurses' perceptions.

BACKGROUND: Antibiotic therapy for asymptomatic bacteriuria in institutionalized elderly people has not been shown to be of benefit and may in fact be harmful; however, antibiotics are still frequently used to treat asymptomatic bacteriuria in this population. The aim of this study was to explore the perceptions, attitudes and opinions of physicians and nurses involved in the process of prescribing antibiotics for asymptomatic bacteriuria in institutionalized elderly people. METHODS: Focus groups were conducted among physicians and nurses who provide care to residents of long-term care facilities in Hamilton, Ont. A total of 22 physicians and 16 nurses participated. The focus group discussions were tape-recorded, and the transcripts of each session were analysed for issues and themes emerging from the text. Content analysis using an open analytic approach was used to explore and understand the experience of the focus group participants. The data from the text were then coded according to the relevant and emergent themes and issues. RESULTS: We observed that the ordering of urine cultures and the prescribing of antibiotics for residents with asymptomatic bacteriuria were influenced by a wide range of nonspecific symptoms or signs in residents. The physicians felt that the presence of these signs justified a decision to order antibiotics. Nurses played a central role in both the ordering of urine cultures and the decision to prescribe antibiotics through their awareness of changes in residents' status and communication of this to physicians. Education about asymptomatic bacteriuria was viewed as an important priority for both physicians and nurses. INTERPRETATION: The presence of non-urinary symptoms and signs is an important factor in the prescription of antibiotics for asymptomatic bacteriuria in institutionalized elderly people. However, no evidence exists to support this reason for antibiotic treatment. Health care providers at long-term care facilities need more education about antibiotic use and asymptomatic bacteriuria.

Aged↗
PubMed2000

Surveillance for outbreaks of respiratory tract infections in nursing homes.

BACKGROUND: Outbreaks of respiratory tract infections are common in long-term care facilities for older people. The objective of our study was to determine both the frequency of such outbreaks and their clinical and epidemiological features. METHODS: Prospective surveillance for outbreaks of respiratory tract infections and a retrospective audit of surveillance records were conducted in 5 nursing homes in metropolitan Toronto over 3 years. The clinical manifestations of infected residents were identified and microbiological investigations for causal agents were conducted. RESULTS: Sixteen outbreaks, involving 480 of 1313 residents, were identified prospectively during 1 144 208 resident-days of surveillance, for an overall rate of 0.42 infections per 1000 resident-days. Another 30 outbreaks, involving 388 residents, were identified retrospectively. Outbreaks occurred year-round, with no seasonal pattern. Pathogens included influenza virus, parainfluenza virus, respiratory syncytial virus, Legionella sainthelensi and Chlamydia pneumoniae. Multiple pathogens were detected in 38% (6/16) of the prospectively identified outbreaks. Of the 480 residents in the prospectively identified outbreaks 398 (83%) had a cough, 194 (40%) had fever and 215 (45%) had coryza. Clinical findings were nonspecific and could not be used to distinguish between causal agents. Pneumonia developed in 72 (15%) of the 480 residents, and 58 (12%) required transfer to hospital. The case-fatality rate was 8% (37/480). INTERPRETATION: Our findings emphasize the importance of adequate surveillance for outbreaks of respiratory tract infections in nursing homes and of early diagnosis so that appropriate interventions can be promptly instituted.

Aged↗
PubMed2000

Cost-effectiveness analysis of six strategies for cardiovascular surgery prophylaxis in patients labeled penicillin allergic.

The cost-effectiveness of different approaches to antimicrobial prophylaxis for cardiovascular surgery patients labeled penicillin allergic was studied. A decision-analytic model was used to examine the cost-effectiveness of six strategies for antimicrobial prophylaxis in cardiovascular surgery patients at a tertiary care hospital. The strategies consisted of (1) giving vancomycin to all patients labeled penicillin allergic, (2) giving cefazolin to all patients labeled penicillin allergic, (3) giving vancomycin to all patients with a history suggesting an immunoglobulin E (IgE)-mediated reaction to penicillin and cefazolin to patients without such a history, (4) administering a penicillin skin test to patients with a history suggesting an IgE-mediated reaction to penicillin and giving vancomycin to patients with positive results and cefazolin to all others, (5) skin testing all patients labeled penicillin allergic and giving vancomycin to those with positive results and cefazolin to those with negative results, regardless of history, and (6) skin testing all patients and giving vancomycin to those with positive results or a history suggesting an IgE-mediated reaction to penicillin and cefazolin to all others. Giving cefazolin to all patients labeled penicillin allergic was the least expensive strategy but was associated with the highest rate of both anaphylactic and non-life-threatening serious reactions. Selective use of vancomycin in patients with a history suggesting an IgE-mediated reaction to penicillin was associated with an added cost and a slightly lower rate of anaphylaxis. Although skin-testing strategies may decrease both non-life-threatening and anaphylactic reactions, the incremental cost was high. When vancomycin was given to all patients labeled penicillin allergic, the incremental cost was very high. A decision-analytic model indicated that selective use of vancomycin is more cost-effective than indiscriminate use of vancomycin for surgical prophylaxis in cardiovascular surgery patients labeled penicillin allergic.

Anti-Bacterial Agents↗
PubMed2000

Evaluation of the BacT/Alert microbial detection system with FAN aerobic and FAN anaerobic bottles for culturing normally sterile body fluids other than blood.

We evaluated the BacT/Alert Microbial Detection System (Organon Teknika Corporation, Durham, NC, USA) by using FAN bottles compared to conventional culture methods for the recovery of microorganisms from normally sterile body fluids other than blood and dialysates. Clinically significant pathogens were isolated from 116 (11%) of 1, 099 consecutive specimens (80 from both conventional media and FAN bottles; 23 from FAN bottles only; 13 from conventional media only). Gram-positive cocci were more likely to be recovered from FAN bottles than from conventional media (p = 0.04). Contaminants were also more likely to have grown in FAN bottles (3%) than on conventional media (1%) (p = 0.04). The mean time to detection of significant pathogens was 20.9 h using FAN bottles as compared to 30. 9 h using conventional media (p = 0.0001). These results indicate that the BacT/Alert Microbial Detection System using FAN blood culture bottles improves the yield of clinically significant Gram-positive isolates from normally sterile body fluids with a reduced time to detection.

Anaerobiosis↗
PubMed2000

PCR detection of Escherichia coli O157:H7 directly from stools: evaluation of commercial extraction methods for purifying fecal DNA.

Rapid identification of Escherichia coli O157:H7 is important for patient management and for prompt epidemiological investigations. We evaluated one in-house method and three commercially available kits for their ability to extract E. coli O157:H7 DNA directly from stool specimens for PCR. Of the 153 stool specimens tested, 107 were culture positive and 46 were culture negative. The sensitivities and specificities of the in-house enrichment method, IsoQuick kit, NucliSens kit, and QIAamp kit were comparable, as follows: 83 and 98%, 85 and 100%, 74 and 98%, and 86 and 100%, respectively. False-negative PCR results may be due to the presence of either inherent inhibitors or small numbers of organisms. The presence of large amounts of bacteria relative to the amount of the E. coli O157:H7 target may result in the lower sensitivities of the assays. All commercial kits were rapid and easy to use, although DNA extracted with the QIAamp kit did not require further dilution of the DNA template prior to PCR.

Culture Media↗
PubMed2000

Evaluation of three rapid methods for detection of methicillin resistance in Staphylococcus aureus.

The probe-based Velogene Rapid MRSA Identification Assay (ID Biomedical Corp., Vancouver, British Columbia, Canada) and the latex agglutination MRSA-Screen (Denka Seiken Co., Tokyo, Japan) were evaluated for their ability to identify methicillin-resistant Staphylococcus aureus (MRSA) and to distinguish strains of MRSA from borderline oxacillin-resistant S. aureus (BORSA; mecA-negative, oxacillin MICs of 2 to 8 microgram/ml). The Velogene is a 90-min assay using a chimeric probe to detect the mecA gene. MRSA-Screen is a 15-min latex agglutination test with penicillin-binding protein 2a antibody-sensitized latex particles. We compared these assays with the BBL Crystal MRSA ID System (Becton Dickinson, Cockeysville, Md.) and with PCR for mecA gene detection. A total of 397 clinical isolates of S. aureus were tested, consisting of 164 methicillin-susceptible strains, 197 MRSA strains, and 37 BORSA strains. All assays performed well for the identification of MRSA with sensitivities and specificities for Velogene, MRSA-Screen, and BBL Crystal MRSA ID of 98.5 and 100%, 98.5 and 100%, and 98.5 and 98%, respectively. Three MRSA strains were not correctly identified by each of the Velogene and MRSA-Screen assays, but repeat testing with a larger inoculum resolved the discrepancies. The BBL Crystal MRSA ID test misclassified four BORSA strains as MRSA. Both the Velogene and the MRSA-Screen assays are easy to perform, can accurately differentiate BORSA isolates from MRSA isolates, and provide a rapid alternative for the detection of methicillin resistance in S. aureus in clinical laboratories, especially when mecA PCR gene detection is unavailable.

Bacterial Proteins↗