Browsing by Author "Gregson, Daniel B."
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- ItemOpen AccessA Case of Acute Cholecystitis Caused by Methicillin-Resistant Staphylococcus aureus in an Immunocompromised Patient(2011-01-01) Kim, Joseph; Gregson, Daniel B.; Church, Deirdre L.Although infections with Staphylococcus aureus can implicate multiple organ systems, involvement of the biliary tract is rare. A case of acute cholecystitis and bacteremia with methicillin-resistant S aureus (MRSA) in a patient with HIV infection is presented. The MRSA isolate was found to be a community-associated strain. The present case highlights the invasive nature of staphylococcal infections and the emerging importance of community-associated MRSA strains.
- ItemOpen AccessClinical outcome of empiric antimicrobial therapy of bacteremia due to extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella pneumoniae(BioMed Central, 2010-04-27) Chaubey, Vikas P.; Pitout, Johann D. D.; Dalton, Bruce; Ross, Terry; Church, Deirdre L.; Gregson, Daniel B.; Laupland, Kevin B.
- ItemOpen AccessThe distinct category of healthcare associated bloodstream infections(BioMed Central, 2012-04-09) Lenz, Ryan; Leal, Jenine R.; Church, Deirdre L.; Gregson, Daniel B.; Ross, Terry; Laupland, Kevin B.
- ItemOpen AccessEpidemiology and risk factors for pyogenic liver abscess in the Calgary Health Zone revisited: a population-based study(2021-09-10) Losie, Jennifer A.; Lam, John C.; Gregson, Daniel B.; Parkins, Michael D.Abstract Background Pyogenic liver abscess (PLA), although uncommon in North America, is associated with significant morbidity and mortality. We sought to re-examine the epidemiology, risk factors, and outcomes of PLA in a large, diverse Canadian health zone. Methods All Calgary Health Zone (CHZ) residents aged ≥20 with PLA between 2015 and 2017 were identified. Incidence and mortality rates were calculated using census data. Risk factors for PLA were identified using a multivariate analysis. Data was compared to 1999–2003 data, also collected in the CHZ. Results There were 136 patients diagnosed with PLA between 2015 and 2017. Incidence rate during this period increased significantly relative to 1999–2003 (3.7 vs 2.3 cases/100,000 population, p < 0.01), however, mortality rates remained similar. The microbiological composition of PLA did not change over this 15-year time period but the number of antimicrobial resistant isolates did increase (8% vs 1%, p = 0.04). The greatest risk factors for PLA relative to general populations included current malignancy, liver-transplant, end-stage renal disease, and cirrhosis. Thirty-day mortality was 7.4% and independent risk factors included polymicrobial bacteremia, absence of abscess drainage, congestive-heart failure, a history of liver disease, and admission bilirubin. Conclusions Pyogenic liver abscess is a health concern with rising incidence rate. The increasing prevalence of comorbidities in our population and factors that are associated with risk of PLA suggests this will continue to be an emerging diagnosis of concern. Increasing prevalence of antibiotic resistant organisms compounding unclear optimal treatment regimens is an issue that requires urgent study.
- ItemOpen AccessIncidence, risk factors, and outcomes of Fusobacterium species bacteremia(BioMed Central, 2013-06-05) Afra, Kevin; Laupland, Kevin; Leal, Jenine; Lloyd, Tracie; Gregson, Daniel B.
- ItemOpen AccessIncidence, susceptibility and outcomes of candidemia in adults living in Calgary, Alberta, Canada (2010–2018)(2023-02-20) Bourassa-Blanchette, Samuel; Biesheuvel, Marit M.; Lam, John C.; Kipp, Alexander; Church, Deirdre; Carson, Julie; Dalton, Bruce; Parkins, Michael D.; Barkema, Herman W.; Gregson, Daniel B.Abstract Background Candidemia is increasing in frequency and is associated with high mortality. We sought to determine the burden of illness, the population it affects and its resistance profile in our region. Methods The Calgary Zone (CZ) provides all care for residents of Calgary and surrounding communities (~ 1.69 million) via five tertiary hospitals each served by a common single laboratory for acute care microbiology. All adult patients in the CZ with at least one Candida spp.-positive blood culture between January 1, 2010, and December 31, 2018, were identified using microbiological data from Calgary Lab Services, the laboratory that processes > 95% of all blood culture samples in the CZ, were reviewed for the study. Results The overall annual incidence of candidemia among individuals living in the CZ was 3.8 per 100,000 persons (Median age 61 years (IQR 48–72) and 221/455 (47.4%) were female). C. albicans was the most common species (50.6%), followed by C. glabrata, (24.0%). No other species accounted for more than 7% of cases. Overall mortality at 30, 90, and 365 days was 32.2, 40.1, and 48.1% respectively. Mortality rate did not differ by Candida species. Of individuals who developed candidemia, more than 50% died within the next year. No new resistance pattern has emerged in the most common Candida species in Calgary, Alberta. Conclusions In Calgary, Alberta, the incidence of candidemia has not increased in the last decade. C. albicans was the most common species and it remains susceptible to fluconazole.
- ItemOpen AccessIncreasing incidence and antimicrobial resistance in Escherichia coli bloodstream infections: a multinational population-based cohort study(2021-09-06) MacKinnon, Melissa C.; McEwen, Scott A.; Pearl, David L.; Lyytikäinen, Outi; Jacobsson, Gunnar; Collignon, Peter; Gregson, Daniel B.; Valiquette, Louis; Laupland, Kevin B.Abstract Background Escherichia coli is an important pathogen in humans and is the most common cause of bacterial bloodstream infections (BSIs). The objectives of our study were to determine factors associated with E. coli BSI incidence rate and third-generation cephalosporin resistance in a multinational population-based cohort. Methods We included all incident E. coli BSIs (2014–2018) from national (Finland) and regional (Australia [Canberra], Sweden [Skaraborg], and Canada [Calgary, Sherbrooke, and western interior]) surveillance. Incidence rates were directly age and sex standardized to the European Union 28-country 2018 population. Multivariable negative binomial and logistic regression models estimated factors significantly associated with E. coli BSI incidence rate and third-generation cephalosporin resistance, respectively. The explanatory variables considered for inclusion in both models were year (2014–2018), region (six areas), age (< 70-years-old and ≥ 70-years-old), and sex (female and male). Results We identified 31,889 E. coli BSIs from 40.7 million person-years of surveillance. Overall and third-generation cephalosporin-resistant standardized rates were 87.1 and 6.6 cases/100,000 person-years, respectively, and increased 14.0% and 40.1% over the five-year study. Overall, 7.8% (2483/31889) of E. coli BSIs were third-generation cephalosporin-resistant. Calgary, Canberra, Sherbrooke, and western interior had significantly lower E. coli BSI rates compared to Finland. The significant association between age and E. coli BSI rate varied with sex. Calgary, Canberra, and western interior had significantly greater odds of third-generation cephalosporin-resistant E. coli BSIs compared to Finland. Compared to 2014, the odds of third-generation cephalosporin-resistant E. coli BSIs were significantly increased in 2016, 2017, and 2018. The significant association between age and the odds of having a third-generation cephalosporin-resistant E. coli BSI varied with sex. Conclusions Increases in overall and third-generation cephalosporin-resistant standardized E. coli BSI rates were clinically important. Overall, E. coli BSI incidence rates were 40–104% greater than previous investigations from the same study areas. Region, sex, and age are important variables when analyzing E. coli BSI rates and third-generation cephalosporin resistance in E. coli BSIs. Considering E. coli is the most common cause of BSIs, this increasing burden and evolving third-generation cephalosporin resistance will have an important impact on human health, especially in aging populations.
- ItemOpen AccessMortality in Escherichia coli bloodstream infections: a multinational population-based cohort study(2021-06-25) MacKinnon, Melissa C.; McEwen, Scott A.; Pearl, David L.; Lyytikäinen, Outi; Jacobsson, Gunnar; Collignon, Peter; Gregson, Daniel B.; Valiquette, Louis; Laupland, Kevin B.Abstract Background Escherichia coli is the most common cause of bloodstream infections (BSIs) and mortality is an important aspect of burden of disease. Using a multinational population-based cohort of E. coli BSIs, our objectives were to evaluate 30-day case fatality risk and mortality rate, and determine factors associated with each. Methods During 2014–2018, we identified 30-day deaths from all incident E. coli BSIs from surveillance nationally in Finland, and regionally in Sweden (Skaraborg) and Canada (Calgary, Sherbrooke, western interior). We used a multivariable logistic regression model to estimate factors associated with 30-day case fatality risk. The explanatory variables considered for inclusion were year (2014–2018), region (five areas), age (< 70-years-old, ≥70-years-old), sex (female, male), third-generation cephalosporin (3GC) resistance (susceptible, resistant), and location of onset (community-onset, hospital-onset). The European Union 28-country 2018 population was used to directly age and sex standardize mortality rates. We used a multivariable Poisson model to estimate factors associated with mortality rate, and year, region, age and sex were considered for inclusion. Results From 38.7 million person-years of surveillance, we identified 2961 30-day deaths in 30,923 incident E. coli BSIs. The overall 30-day case fatality risk was 9.6% (2961/30923). Calgary, Skaraborg, and western interior had significantly increased odds of 30-day mortality compared to Finland. Hospital-onset and 3GC-resistant E. coli BSIs had significantly increased odds of mortality compared to community-onset and 3GC-susceptible. The significant association between age and odds of mortality varied with sex, and contrasts were used to interpret this interaction relationship. The overall standardized 30-day mortality rate was 8.5 deaths/100,000 person-years. Sherbrooke had a significantly lower 30-day mortality rate compared to Finland. Patients that were either ≥70-years-old or male both experienced significantly higher mortality rates than those < 70-years-old or female. Conclusions In our study populations, region, age, and sex were significantly associated with both 30-day case fatality risk and mortality rate. Additionally, 3GC resistance and location of onset were significantly associated with 30-day case fatality risk. Escherichia coli BSIs caused a considerable burden of disease from 30-day mortality. When analyzing population-based mortality data, it is important to explore mortality through two lenses, mortality rate and case fatality risk.
- ItemOpen AccessPlasmid mediated AmpC B-lactamases in E. coli clinical isolated in Calgary Health Region (CHR)(2005) Nasim, Khalida; Gregson, Daniel B.; Church, Deirdre
- ItemOpen AccessPopulation-Based Laboratory Surveillance of Imported Malaria in Metropolitan Calgary, 2000–2011(PLoS ONE, 2013-04-15) Lee, Clara S.; Gregson, Daniel B.; Church, Deirdre; Laupland, Kevin B.; Eckhardt, Rose; Ross, Terry; Chan, Wilson; Pillai, Dylan R.
- ItemOpen AccessThe Validation of a Novel Surveillance System for Monitoring Bloodstream Infections in the Calgary Zone(2016-06-07) Leal, Jenine R.; Gregson, Daniel B.; Church, Deirdre L.; Henderson, Elizabeth A.; Ross, Terry; Laupland, Kevin B.Background. Electronic surveillance systems (ESSs) that utilize existing information in databases are more efficient than conventional infection surveillance methods. The objective was to assess an ESS for bloodstream infections (BSIs) in the Calgary Zone for its agreement with traditional medical record review. Methods. The ESS was developed by linking related data from regional laboratory and hospital administrative databases and using set definitions for excluding contaminants and duplicate isolates. Infections were classified as hospital-acquired (HA), healthcare-associated community-onset (HCA), or community-acquired (CA). A random sample of patients from the ESS was then compared with independent medical record review. Results. Among the 308 patients selected for comparative review, the ESS identified 318 episodes of BSI of which 130 (40.9%) were CA, 98 (30.8%) were HCA, and 90 (28.3%) were HA. Medical record review identified 313 episodes of which 136 (43.4%) were CA, 97 (30.9%) were HCA, and 80 (25.6%) were HA. Episodes of BSI were concordant in 304 (97%) cases. Overall, there was 85.5% agreement between ESS and medical record review for the classification of where BSIs were acquired (kappa = 0.78, 95% Confidence Interval: 0.75–0.80). Conclusion. This novel ESS identified and classified BSIs with a high degree of accuracy. This system requires additional linkages with other related databases.