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Biomedical subjects

Elizabeth Bryce

Publications and source records attributed to Elizabeth Bryce.

13 recordsLinked to original sources

Methicillin-resistant Staphylococcus aureus in Canadian aboriginal people.

We describe 279 hospitalized Canadian aboriginals in whom methicillin-resistant Staphylococcus aureus (MRSA) was detected. They were identified in 38 Canadian hospitals from 1995 through 2002. Compared with nonaboriginals, aboriginals were more likely to be younger than 18 years of age (OR, 1.8; P<.0001), to have had an MRSA infection (OR, 3.8; P<.0001), and to have had MRSA isolated from specimens of skin or soft tissue (OR, 4.1; P=.016). The clinical features of MRSA infection in aboriginals are distinct from those in the general patient population with MRSA infection in Canadian hospitals, and the genetic background of MRSA isolates from aboriginals also varies from that of strains from the non-aboriginal population.

Adolescent↗

Coordinated response to SARS, Vancouver, Canada.

Two Canadian urban areas received travelers with severe acute respiratory syndrome (SARS) before the World Health Organization issued its alert. By July 2003, Vancouver had identified 5 cases (4 imported); Toronto reported 247 cases (3 imported) and 43 deaths. Baseline preparedness for pandemic threats may account for the absence of sustained transmission and fewer cases of SARS in Vancouver.

Adult↗

Protecting health care workers from SARS and other respiratory pathogens: organizational and individual factors that affect adherence to infection control guidelines.

BACKGROUND: Traditional infection control policies have focused on engineering controls, specific protocols, and personal protective equipment (PPE). In light of the variable success in protecting health care workers (HCWs) from Severe Acute Respiratory Syndrome (SARS) in 2003, organizational and individual factors related to self-protective behavior in health care settings may also play an important role. METHODS: A critical review of the literature was conducted, directed at understanding what organizational and individual factors are important in protecting HCWs from infectious diseases at work. RESULTS: Organizational factors, such as a positive safety climate, have been associated with increased HCW adherence to universal precautions. There is some evidence that appropriate training of HCWs could be effective in changing HCW behavior if appropriate follow-up is applied. Very little research into these factors has been conducted with regard to preventing exposures to respiratory tract pathogens, but there was evidence from the SARS outbreaks that training programs and the availability of adequate PPE were associated with a decrease risk of infection. CONCLUSION: Variations in organizational and individual factors can explain much of the variations in self-protective behavior in health care settings. It is likely that these factors were also important determinants during the SARS outbreaks, but they have not been extensively studied.

Canada↗

Protecting health care workers from SARS and other respiratory pathogens: a review of the infection control literature.

BACKGROUND: Severe Acute Respiratory Syndrome (SARS) was responsible for outbreaks in Canada, China, Hong Kong, Vietnam, and Singapore. SARS focused attention on the adequacy of and compliance with infection control practices in preventing airborne and droplet-spread transmission of infectious agents. METHODS: This paper presents a review of the current scientific knowledge with respect to the efficacy of personal protective equipment in preventing the transmission of respiratory infections. The effectiveness of infection control policies and procedures used in clinical practice is examined. RESULTS: Literature searches were conducted in several databases for articles published in the last 15 years that related to infection control practices, occupational health and safety issues, environmental factors, and other issues of importance in protecting workers against respiratory infections in health care settings. CONCLUSION: Failure to implement appropriate barrier precautions is responsible for most nosocomial transmissions. However, the possibility of a gradation of infectious particles generated by aerosolizing procedures suggests that traditional droplet transmission prevention measures may be inadequate in some settings. Further research is needed in this area.

Humans↗

Clinical and epidemiologic features of methicillin-resistant Staphylococcus aureus in elderly hospitalized patients.

We describe characteristics of elderly patients with MRSA identified in 37 Canadian hospitals between 1995 and 2002. Of these inpatients, 6,613 (66%) were older than 65 years. They were more likely than younger patients to have been colonized without infection and to have had MRSA isolated from urine or the perineum. The epidemiology and clinical features of these patients is distinct from that of younger patients.

Adult↗

Research gaps in protecting healthcare workers from SARS and other respiratory pathogens: an interdisciplinary, multi-stakeholder, evidence-based approach.

OBJECTIVE: To identify priorities for further research in protecting healthcare workers (HCWs) from severe acute respiratory syndrome (SARS) and other respiratory pathogens by summarizing the basic science of infectious bioaerosols and the efficacy of facial protective equipment; the organizational, environmental, and individual factors that influence the success of infection control and occupational health programs; and factors identified by HCWs as important. METHOD: An extensive literature review was conducted and 15 focus groups held, mostly with frontline HCWs in Toronto. Critical gaps in knowledge were identified and prioritized. RESULTS: Highest priority was given to organizational factors that create a climate of safety. Other priority areas included understanding aerosolization risks and practical measures to control bioaerosols at the source. CONCLUSIONS: Further research is warranted to improve safety climate in health care and, specifically, to provide greater protection against respiratory pathogens.

Canada↗

Molecular characterization of cefoxitin-resistant Escherichia coli from Canadian hospitals.

A study designed to gain baseline information on strains of Escherichia coli displaying resistance to cefoxitin in Canada is described. A total of 29,323 E. coli isolates were screened at 12 participating hospital sites as part of an extended-spectrum beta-lactamase surveillance initiative. A total of 411 clinically significant, nonrepeat isolates displaying reduced susceptibilities to the NCCLS-recommended beta-lactams were submitted to a central laboratory over a 1-year period ending on 30 September 2000. Two hundred thirty-two isolates were identified as resistant to cefoxitin. All cefoxitin-resistant strains were subtyped by pulsed-field gel electrophoresis, and of these, 182 strains revealed a unique fingerprint and 1 strain was untypeable. PCR and sequence analysis of the ampC promoter region revealed 51 different promoter or attenuator variants and 14 wild-type promoters. Three promoter regions were interrupted by insertion elements, two contained IS10 elements, and one contained an IS911 variant. PCR and sequence analysis for the detection of acquired AmpC resistance (by the acquisition of ACT-1/MIR-1, CMY-2, or FOX) revealed that 25 strains contained CMY-2, including 7 of the strains found to have wild-type promoters. The considerable genetic variability in both the strain fingerprint and the promoter region suggests that AmpC-type resistance may emerge spontaneously by mutation of sensitive strains rather than by the spread of strains or plasmids in the hospital setting.

Anti-Bacterial Agents↗

Occupational health and infection control practices related to severe acute respiratory syndrome: health care worker perceptions.

The spread of severe acute respiratory syndrome (SARS) in 2003 was largely driven by hospital-associated transmission where health care workers experienced the largest burden of disease. In attempting to improve occupational health and infection control procedures to prevent occupationally acquired infections in health care workers, it is important to examine the perceptions of those workers who are expected to adhere to specific policies. The authors conducted 15 focus groups of health care workers representing seven different job classifications in two Canadian provinces where SARS outbreaks occurred in 2003 using a theoretical framework which divided factors associated with self-protective behaviour at work into organizational, environmental, and individual factors. Content analysis of these discussions revealed that workers placed more importance on organizational factors than environmental and individual factors. The results are similar to those of a recently completed literature review of this subject, and should be considered when developing new occupational health initiatives to protect health care workers from existing or emerging respiratory tract infections.

Adult↗

Complete nucleotide sequence of a 92-kilobase plasmid harboring the CTX-M-15 extended-spectrum beta-lactamase involved in an outbreak in long-term-care facilities in Toronto, Canada.

A major outbreak involving an Escherichia coli strain that was resistant to expanded-spectrum cephalosporins occurred in Toronto and surrounding regions in 2000 to 2002. We report the complete sequence of a plasmid, pC15-1a, that was found associated with the outbreak strain. Plasmid pC15-1a is a circular molecule of 92,353 bp consisting of two distinct regions. The first is a 64-kb region that is essentially homologous to the non-R-determinant region of plasmid R100 except for several point mutations, a few small insertions and deletions, and the absence of Tn10. The second is a 28.4-kb multidrug resistance region (MDR) that has replaced the R-determinant region of the R100 progenitor and consists mostly of transposons or partial transposons and five copies of the insertion element IS26. All drug resistance genes found in pC15-1a, including the beta-lactamase genes bla(CTX-M-15), bla(OXA-1), and bla(TEM-1), the tetracycline resistance gene tetA, and aminoglycoside resistance genes aac(6')-Ib and aac(3)-II, are located in the MDR. The bla(CTX-M-15) gene was found downstream of ISEcp1as part of a transposition unit, as determined from the surrounding sequence. Examination of the plasmids from CTX-M-15-harboring strains isolated from hospitals across Canada showed that pC15-1a was found in several strains isolated from a site in western Canada. Comparison of pC15-1a and pCTX15, found in an E. coli strain isolated in India in 1999, revealed that the plasmids had several features in common, including an R100 backbone and several of the resistance genes, including bla(CTX-M-15), bla(TEM-1), bla(OXA-1), tetA, and aac(6')-Ib.

Base Sequence↗

Ambler class A extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella spp. in Canadian hospitals.

This report describes a study carried out to gain baseline information on the molecular characteristics of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella spp. in Canada. A total of 29,323 E. coli and 5,156 Klebsiella sp. isolates were screened at 12 participating sites. Of these, 505 clinically significant, nonrepeat isolates displaying reduced susceptibility to the NCCLS-recommended beta-lactams were submitted to a central laboratory over a 1-year period ending on 30 September 2000. A total of 116 isolates were confirmed to be ESBL producers. PCR and sequence analysis revealed the presence of TEM-11 (n = 1), TEM-12 (n = 1), TEM-29 (n = 1), TEM-52 (n = 4), CTX-M-13 (n = 1), CTX-M-14 (n = 15), CTX-M-15 (n = 11), SHV-2 (n = 2), SHV-2a (n = 12), SHV-5 (n = 6), SHV-12 (n = 45), and SHV-30 (n = 2). Five novel beta-lactamases were identified and designated TEM-115 (n = 2), TEM-120 (n = 1), SHV-40 (n = 2), SHV-41 (n = 4), and SHV-42 (n = 1). In addition, no molecular mechanism was identified for five isolates displaying an ESBL phenotype. Macrorestriction analysis of all ESBL isolates was conducted, as was restriction fragment length polymorphism analysis of plasmids harboring ESBLs. Although a "clonal" distribution of isolates was observed at some individual sites, there was very little evidence suggesting intrahospital spread. In addition, examples of identical or closely related plasmids that were identified at geographically distinct sites across Canada are given. However, there was considerable diversity with respect to plasmid types observed.

Anti-Bacterial Agents↗

The state of infection surveillance and control in Canadian acute care hospitals.

BACKGROUND: Nosocomial infections and antibiotic-resistant pathogens cause significant morbidity, mortality, and economic costs. The infection surveillance and control resources and activities in Canadian acute care hospitals had not been assessed in 20 years. METHODS: In 2000, surveys were mailed to infection control programs in all Canadian hospitals with more than 80 acute care beds. The survey was modeled after the US Study on the Efficacy of Nosocomial Infection Control instrument, with new items dealing with resistant pathogens and computerization. Surveillance and control indices were calculated. RESULTS: One hundred seventy-two of 238 (72.3%) hospitals responded. In 42.1% of hospitals, there was fewer than 1 infection control practitioner per 250 beds. Just 60% of infection control programs had physicians or doctoral professionals with infection control training who provided services. The median surveillance index was 65.6/100, and the median control index was 60.5/100. Surgical site infection rates were reported to individual surgeons in only 36.8% of hospitals. CONCLUSIONS: There were deficits in the identified components of effective infection control programs. Greater investment in resources is needed to meet recommended standards and thereby reduce morbidity, mortality, and expense associated with nosocomial infections and antibiotic-resistant pathogens.

Acute Disease↗

Laboratory characterization of methicillin-resistant Staphylococcus aureus in Canadian hospitals: results of 5 years of National Surveillance, 1995-1999.

Two thousand seven hundred eighty single-patient, methicillin-resistant Staphylococcus aureus (MRSA) isolates collected between January 1995 and December 1999 at 17 tertiary care hospital sites across Canada were characterized by phenotypic and genotypic techniques. Six clonal types, as defined by pulsed-field gel electrophoresis, comprised 87% of all isolates and were labeled Canadian (C) MRSA-1 through -6. CMRSA-1 was the most prevalent clonal type, representing 45% of all MRSA. CMRSA-2 was indistinguishable from the New York clone and was more likely to be associated with community acquisition. CMRSA-3 was more likely to cause an infection, compared with the other CMRSA types. CMRSA-4 was indistinguishable from epidemic (E) MRSA-16 from the United Kingdom. Both CMRSA-5 and -6 occurred primarily in single-site, multiyear outbreaks. This study confirms that the epidemiology of MRSA in Canada is evolving, but most isolates at this time appear to belong to one of a small number of epidemic clones.

Bacterial Proteins↗