Browsing by Author "Church, Deirdre L."

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    A 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.
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    A pragmatic randomized controlled trial of rapid on-site influenza and respiratory syncytial virus PCR testing in paediatric and adult populations
    (2022-11-16) Bibby, Helen L.; de Koning, Lawrence; Seiden-Long, Isolde; Zelyas, Nathan; Church, Deirdre L.; Berenger, Byron M.
    Abstract Background Rapid/point-of-care respiratory virus nucleic acid tests (NAT) may improve oseltamivir, antibiotic, diagnostic test, and hospital bed utilization. Previous randomized controlled trials (RCT) on this topic have not used standard procedures of an accredited healthcare and laboratory system. Methods We conducted a parallel RCT at two hospitals [paediatric = Alberta Children’s Hospital (ACH); primarily adult = Peter Lougheed Centre (PLC)]. Patients with a respiratory viral testing order were randomized to testing at either a central accredited laboratory (standard arm) or with a rapid polymerase chain reaction test at an on-site accredited laboratory followed by standard testing [rapid on-site test (ROST) arm] based on day of specimen receipt at the laboratory. Patients and clinicians were blinded to assignment. The primary outcome for ACH was inpatient length of stay (LOS) and for PLC was the proportion of inpatients prescribed oseltamivir. Results 706 patient encounters were included at ACH; 322 assigned to ROST (181 inpatients) and 384 to the standard arm (194 inpatients). 422 patient encounters were included at PLC; 200 assigned to ROST (157 inpatients) and 222 to the standard arm (175 inpatients). The rate of oseltamivir prescription and number of doses given was reduced in PLC inpatients negative for influenza in the ROST arm compared to standard arm [mean 14.9% (95% CI 9.87–21.9) vs. 27.5% (21.0–35.2), p = 0.0135; mean 2.85 doses (SEM 2.39–3.32) vs. 4.17 doses (3.85–4.49) p = 0.022, respectively]. ROST also significantly reduced oseltamivir use at ACH, reduced chest radiographs (ACH), and laboratory test ordering (PLC), but not antibiotic prescriptions. ROST also reduced the median turnaround time by > 24 h (ACH and PLC). The LOS at ACH was not significantly different between the ROST and standard arms [median 4.05 days (SEM 1.79–18.2) vs 4.89 days (2.07–22.9), p = 0.062, respectively]. No adverse events were reported. Conclusions In a RCT representing implementation of ROST in an accredited laboratory system, we found that a ROST improved oseltamivir utilization and is the first RCT to show reduced ancillary testing in both paediatric and adult populations. A larger study is required to assess reduction in paediatric LOS as ACH was underpowered. These findings help justify the implementation of rapid on-site respiratory virus testing for inpatients. Trial registration ISRCTN, number 10110119, Retrospectively Registered, 01/12/2021.
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    Clinical epidemiology and impact of Haemophilus influenzae airway infections in adults with cystic fibrosis
    (2024-10-27) Weyant, R. Benson; Waddell, Barbara J.; Acosta, Nicole; Izydorczyk, Conrad; Conly, John M.; Church, Deirdre L.; Surette, Michael G.; Rabin, Harvey R.; Thornton, Christina S.; Parkins, Michael D.
    Abstract Background Haemophilus influenzae is prevalent within the airways of persons with cystic fibrosis (pwCF). H. influenzae is often associated with pulmonary exacerbations (PEx) in pediatric cohorts, but in adults, studies have yielded conflicting reports around the impact(s) on clinical outcomes such as lung function decline. Accordingly, we sought to discern the prevalence, natural history, and clinical impact of H. influenzae in adult pwCF. Methods This single-centre retrospective cohort study reviewed all adult pwCF with H. influenzae sputum cultures between 2002 and 2016. From this cohort, persistently infected subjects (defined as: ≥2 samples with the same pulsotype and > 50% sputum culture-positive for H. influenzae in each year) were matched (1:2) to controls without H. influenzae. Demographic and clinical status (baseline health or during periods of PEx) were obtained at each visit that H. influenzae was cultured. Yearly biobank isolates were typed using pulsed-field gel electrophoresis (PFGE) to assess relatedness. Results Over the study period, 30% (n = 70/240) of pwCF were culture positive for H. influenzae, of which 38 (54%) were culture-positive on multiple occasions and 12 (17%) had persistent infection. One hundred and thirty-seven isolates underwent PFGE, with 94 unique pulsotypes identified. Two (1.5%) were serotype f with the rest non-typeable (98.5%). H. influenzae isolation was associated with an increased risk of PEx (RR = 1.61 [1.14–2.27], p = 0.006), however, this association was lost when we excluded those who irregularly produced sputum (i.e. only during a PEx). Annual lung function decline did not differ across cohorts. Conclusions Isolation of H. influenzae was common amongst adult pwCF but often transient. H. influenzae infection was not associated with acute PEx or chronic lung function decline.
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    Clinical 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.
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    The 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.
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    The 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.