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5.  Clinical and microbiological characteristics of bloodstream infections due to AmpC β-lactamase producing Enterobacteriaceae: an active surveillance cohort in a large centralized Canadian region 
BMC Infectious Diseases  2014;14(1):647.
The objective of this study was to describe the clinical and microbiological characteristics of bloodstream infections (BSIs) due to AmpC producing Enterobacteriaceae (AE) in a large centralized Canadian region over a 9-year period.
An active surveillance cohort design in Calgary, Canada.
A cohort of 458 episodes of BSIs caused by AE was assembled for analysis. The majority of infections were of nosocomial origin with unknown sources. Enterobacter spp. was the most common species while BSIs due to Serratia spp. had a significant higher mortality when compared to other AE. Delays in empiric or definitive antibiotic therapy were not associated with a difference in outcome. However, patients that did not receive any empiric antimicrobial therapy had increased mortality (3/5; 60% vs. 57/453; 13%; p = 0.018) as did those that did not receive definitive therapy (6/17; 35% vs. 54/441; 12%; p = 0.015).
Delays in therapy were not associated with adverse outcomes although lack of active therapy was associated with increased mortality. A strategy for BSIs due to AE where β-lactam antibiotics (including oxyimino-cephalosporins) are used initially followed by a switch to non-β-lactam antibiotics once susceptibility results are available is effective.
PMCID: PMC4299784  PMID: 25494640
Beta-lactamases; Bacteremia; Enterobacteriaceae
8.  Population-based surveillance for hypermucoviscosity Klebsiella pneumoniae causing community-acquired bacteremia in Calgary, Alberta 
The characteristics of hypermucoviscosity isolates among Klebsiella pneumoniae causing community-acquired bacteremia were investigated. The hypermucoviscous phenotype was present in 8.2% of K pneumoniae isolates, and was associated with rmpA and the K2 serotype; liver abscesses were the most common clinical presentation. The present analysis represents the first population-based surveillance study of hypermucoviscosity among K pneumoniae causing bacteremia.
PMCID: PMC3852459  PMID: 24421832
Bacteremia; Community acquired; Hypermucoviscous; Klebsiella pneumoniae; Population-based surveillance
10.  Antimicrobial resistance surveillance systems: Are potential biases taken into account? 
The objective of this study was to assess potential biases that may influence the validity of contemporary antimicrobial-resistant (AMR) pathogen surveillance systems. Although surveillance data have been widely published and used by researchers and decision makers, little attention has been devoted to the assessment of their validity. A Medline search was used to identify reports, in 2008, of laboratory-based AMR surveillance systems. Identified surveillance systems were appraised for six different types of bias. Scores were assigned as ‘2’ (good), ‘1’ (fair) and ‘0’ (poor) for each bias. The results of this assessment indicate that there are several potential biases that can influence the validity of AMR surveillance information and, therefore, the potential for bias should be considered in the interpretation and use of AMR surveillance data.
The validity of surveillance systems has rarely been a topic of investigation.
To assess potential biases that may influence the validity of contemporary antimicrobial-resistant (AMR) pathogen surveillance systems.
In 2008, reports of laboratory-based AMR surveillance systems were identified by searching Medline. Surveillance systems were appraised for six different types of bias. Scores were assigned as ‘2’ (good), ‘1’ (fair) and ‘0’ (poor) for each bias.
A total of 22 surveillance systems were included. All studies used appropriate denominator data and case definitions (score of 2). Most (n=18) studies adequately protected against case ascertainment bias (score = 2), with three studies and one study scoring 1 and 0, respectively. Only four studies were deemed to be free of significant sampling bias (score = 2), with 17 studies classified as fair, and one as poor. Eight studies had explicitly removed duplicates (score = 2). Seven studies removed duplicates, but lacked adequate definitions (score = 1). Seven studies did not report duplicate removal (score = 0). Eighteen of the studies were considered to have good laboratory methodology, three had some concerns (score = 1), and one was considered to be poor (score = 0).
Contemporary AMR surveillance systems commonly have methodological limitations with respect to sampling and multiple counting and, to a lesser degree, case ascertainment and laboratory practices. The potential for bias should be considered in the interpretation of surveillance data.
PMCID: PMC3222764  PMID: 23205029
Antimicrobial resistance; Bias; Epidemiology; Incidence; Risk
14.  Surveillance and Molecular Epidemiology of Klebsiella pneumoniae Isolates That Produce Carbapenemases: First Report of OXA-48-Like Enzymes in North America 
A study was designed to characterize nonrepeat isolates of carbapenemase-producing K. pneumoniae obtained from the SMART worldwide surveillance program during 2008 and 2009. Characterization was done by PCR and sequencing for blaVIM, blaIMP, blaNDM, blaOXA, blaKPC, and plasmid-mediated quinolone resistance and virulence factors (VFs). Genetic relatedness was determined with pulsed-field gel electrophoresis (PFGE) using XbaI and multilocus sequence typing. A total of 110 isolates were included; 47 possess genes that encode K. pneumoniae carbapenemases (KPCs), 26 NDMs, 19 VIMs, 13 OXA-48-like, and 5 imipenems (IMPs). We identified 3 different major sequence types (STs) among 65% of the isolates (i.e., ST11 [n = 11], ST147 [n = 23], and ST258 [n = 38]). ST11 and ST147, producing OXA-48-like and NDMs, were found in Argentina, Turkey, Greece, Italy, and India; ST258, producing KPCs, was present in the United States, Israel, Greece, and Puerto Rico. The major STs consisted of up to 4 different pulsotypes, and each pulsotype had a specific geographical distribution. A new ST, named ST903, with blaIMP-26, was identified in the Philippines, while two blaOXA-48-positive isolates were detected in the United States. There were no significant differences in the distribution of the VFs between the isolates; all were positive for fimH, mrkD, wabG, and ureA. This is the first report of OXA-48-like enzymes in North America. Our study highlights the importance of surveillance programs using molecular techniques as powerful tools to identify the importance of international sequence types.
PMCID: PMC3535978  PMID: 23070171
19.  Routine immunization of adults in Canada: Review of the epidemiology of vaccine-preventable diseases and current recommendations for primary prevention 
Vaccination is one of the greatest achievements in public health of the 20th century. However, the success of vaccine uptake and adherence to immunization guidelines seen in pediatric populations has not been observed among adult Canadians. As a result of the disparity in susceptibility to vaccine-preventable disease, there has been an increasing shift of vaccine-preventable childhood diseases into adult populations. Accordingly, morbidity and mortality due to vaccine-preventable illnesses now occur disproportionately in adults. All Canadians, irrespective of age, should have immunity to measles, mumps, rubella, tetanus, diphtheria, pertussis and varicella. All adult Canadians with significant medical comorbidities or those older than 65 years of age should receive the pneumococcal polysaccharide vaccine and yearly trivalent inactivate influenza vaccines. The present review summarizes the burden of illness of these vaccine-preventable diseases in the Canadian adult population and reviews the current immunization recommendations. Vaccination of all Canadians to these common agents remains a vital tool to decrease individual morbidity and mortality and reduce the overall burden of preventable disease in Canada.
PMCID: PMC2770305  PMID: 20808459
Influenza; Measles; Pertussis; Pneumococcus; Tetanus; Varicella
21.  Diagnosis and management of temperature abnormality in ICUs: a EUROBACT investigators' survey 
Critical Care  2013;17(6):R289.
Although fever and hypothermia are common abnormal physical signs observed in patients admitted to intensive care units (ICU), little data exist on their optimal management. The objective of this study was to describe contemporary practices and determinants of management of temperature abnormalities among patients admitted to ICUs.
Site leaders of the multi-national EUROBACT study were surveyed regarding diagnosis and management of temperature abnormalities among patients admitted to their ICUs.
Of the 162 ICUs originally included in EUROBACT, responses were received from 139 (86%) centers in 23 countries in Europe (117), South America (8), Asia (5), North America (4), Australia (3) and Africa (2). A total of 117 (84%) respondents reported use of a specific temperature threshold in their ICU to define fever. A total of 14 different discrete levels were reported with a median of 38.2°C (inter-quartile range, IQR, 38.0°C to 38.5°C). The use of thermometers was protocolized in 91 (65%) ICUs and a wide range of methods were reportedly used, with axillary, tympanic and urinary bladder sites as the most common as primary modalities. Only 31 (22%) of respondents indicated that there was a formal written protocol for temperature control among febrile patients in their ICUs. In most or all cases practice was to control temperature, to use acetaminophen, and to perform a full septic workup in febrile patients and that this was usually directed by physician order. While reported practice was to treat nearly all patients with neurological impairment and most patients with acute coronary syndromes and infections, severe sepsis and septic shock, this was not the case for most patients with liver failure and fever.
A wide range of definitions and management practices were reported regarding temperature abnormalities in the critically ill. Documenting temperature abnormality management practices, including variability in clinical care, is important to inform planning of future studies designed to optimize infection and temperature management strategies in the critically ill.
PMCID: PMC4057370  PMID: 24326145
Fever; hypothermia; intensive care unit; sepsis; septic shock; bacteremia
22.  Community-onset bloodstream infection during the ‘after hours’ is not associated with an increased risk for death 
Patients admitted to hospital during the ‘after hours’ (weekends and evenings) may be at increased risk for adverse outcome. The objective of the present study was to assess whether community-onset bloodstream infections presenting in the after hours are associated with death.
All patients in the Victoria area of British Columbia, who had first admissions with community-onset bloodstream infections between 1998 and 2005 were included. The day of admission to hospital, the day and time of culture draw, and all-cause, in-hospital mortality were ascertained.
A total of 2108 patients were studied. Twenty-six per cent of patients were admitted on a weekend. Blood cultures were drawn on a weekend in 27% of cases and, in 43%, 33%, and 25% of cases, cultures were drawn during the day (08:00 to 17:59), the evening (18:00 to 22:59) and night (23:00 to 07:59), respectively. More than two-thirds (69%) of index cultures were drawn during the after hours (any time Saturday or Sunday and weekdays 18:00 to 07:59). The overall in-hospital case fatality rate was 13%. No difference in mortality was observed in relation to the day of the week of admission or time period of sampling. After-hours sampling was not associated with mortality in a multivariable logistic regression model examining factors associated with death.
Presentation with community-onset, bloodstream infection during the after hours does not increase the risk of death.
PMCID: PMC3597392  PMID: 24294269
Bacteremia; Bloodstream infection; Mortality; Weekend
23.  Factors Influencing Early and Late Mortality in Adults with Invasive Pneumococcal Disease in Calgary, Canada: A Prospective Surveillance Study 
PLoS ONE  2013;8(10):e71924.
Invasive pneumococcal disease continues to be an important cause of mortality. In Calgary, 60% of deaths occur within 5 days of presenting to hospital. This proportion has not changed since before the era of penicillin. The purpose of this study was to investigate what factors may influence death within 5 days of presentation with pneumococcal disease.
Methods and Findings
Demographic and clinical data from the CASPER (Calgary Area Streptococcus pneumoniae Epidemiology Research) study on 1065 episodes of invasive pneumococcal disease in adults (≥18 years) from 2000 to 2010 were analyzed. Adjusted multinomial regression was performed to analyze 3 outcomes: early mortality (<5 days post-presentation), late mortality (5-30 days post-presentation), and survival, generating relative risk ratios (RRR). Patients with severe disease had increased risk of early and late death. In multinomial regression with survivors as baseline, the risk of early death increased in those with a Charlson index ≥2 (RRR: 6.3, 95% CI: 1.8-21.9); the risk of late death increased in those with less severe disease and a Charlson ≥2 (RRR: 6.1, 95% CI: 1.4-27.7). Patients who never received appropriate antibiotics had 5.6X (95% CI: 2.4-13.1) the risk of early death. Risk of both early and late death increased by a RRR of 1.3 (95% CI: 1.2-1.4) per 5-year increase in age. In multinomial regression, there were no significant differences in the effects of the factors tested between early and late mortality.
Presenting with severe invasive pneumococcal disease, multiple comorbidities, and older age increases the risk of both early and late death. Patients who died early often presented too late for effective antibiotic therapy, highlighting the need for an effective vaccine.
PMCID: PMC3793008  PMID: 24115997
24.  Incidence, prevalence, and occurrence rate of infection among adults hospitalized after traumatic brain injury: study protocol for a systematic review and meta-analysis 
Systematic Reviews  2013;2:68.
Infection occurs commonly among patients hospitalized after traumatic brain injury (TBI) and has been associated with increased intensive care unit and hospital lengths of stay and an elevated risk of poor neurological outcome and mortality. However, as many relevant published studies to date have varied in the type and severity of TBI among included patients as well as in their design (randomized versus non-randomized), risk of bias, and setting (hospital ward versus intensive care unit), their reported estimates of infection occurrence vary considerably. Thus, the purpose of this systematic review and meta-analysis is to estimate the incidence, prevalence, and occurrence rate of infection among patients hospitalized after TBI.
We will search electronic bibliographic databases (MEDLINE, EMBASE, PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, Web of Science, the Cochrane Central Register of Controlled Trials (CENTRAL), and the Cochrane Database of Systematic Reviews) from their first available date as well as personal files, reference lists of included articles, and conference proceedings. Two investigators will independently screen titles and abstracts and select cohort studies, cross-sectional studies, and randomized controlled trials involving adults hospitalized after TBI that reported estimates of cumulative incidence, incidence rate, prevalence, or occurrence rate of infection for inclusion in the systematic review. These investigators will also independently extract data and assess risk of bias. We will exclude studies with fewer than ten patients; experimental groups allocated to treatment with antibiotics, glucocorticoids, immunosuppressants, barbiturates, or hypothermia; and studies focused on military/combat-related TBI. Pooled estimates of cumulative incidence, incidence rate, prevalence, and occurrence rate will be calculated using random effects models. We will also calculate I2 and Cochran Q statistics to assess for inter-study heterogeneity and conduct stratified analyses and univariate meta-regression to determine the influence of pre-defined study-level covariates on our pooled estimates.
This study will compile the world literature regarding the epidemiology of infection among adults hospitalized after TBI. A better understanding of the role of infection will be helpful in the development of guidelines for patient management. This protocol has been registered in the PROSPERO International Prospective Register of Systematic Reviews (ID: CRD42013005146).
PMCID: PMC3765722  PMID: 23971513
Craniocerebral trauma; Infection; Incidence; Prevalence; Systematic review; Meta-analysis
25.  Population-Based Laboratory Surveillance of Imported Malaria in Metropolitan Calgary, 2000–2011 
PLoS ONE  2013;8(4):e60751.
Increased travel leads to a heightened risk of imported infectious diseases. Patterns of immigration to countries like Canada have changed such that countries of malaria endemicity are frequented in larger numbers. In keeping with the changes in travel patterns and immigration, the major metropolitan city of Calgary has seen a dramatic rise in malaria incidence over the last decade. Fuelling this rise in Calgary has been the apparent complacence with prophylaxis in individuals visiting friends and relatives and potentially inadequate public health intervention in areas of the city with increased immigration and lower socioeconomic status.
PMCID: PMC3626683  PMID: 23613742

Results 1-25 (63)