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Biomedical subjects

D B Gregson

Publications and source records attributed to D B Gregson.

9 recordsLinked to original sources
PubMed2006

Burden of community-onset bloodstream infection: a population-based assessment.

Although community-onset bloodstream infection (BSI) is recognized to be a major cause of morbidity and mortality, there is a paucity of population-based studies defining its overall burden. We conducted population-based laboratory surveillance for all community-onset BSI in the Calgary Health Region during 2000-2004. A total of 4467 episodes of community-onset BSI were identified for an overall annual incidence of 81.6/100,000. The three species, Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae were responsible for the majority of community-onset BSI; they occurred at annual rates of 25.8, 13.5, and 10.1/100,000, respectively. Overall 3445/4467 (77%) episodes resulted in hospital admission representing 0.7% of all admissions to major acute care hospitals. The subsequent hospital length of stay was a median of 9 (interquartile range, 5-15) days; the total days of acute hospitalization attributable to community-onset BSI was 51,146 days or 934 days/100,000 annually. Four hundred and sixty patients died in hospital for a case-fatality rate of 13%. Community-onset BSI is common and has a major patient and societal impact. These data support further efforts to reduce the burden of community-onset BSI.

Adolescent↗
PubMed2006

Cost of intensive care unit-acquired bloodstream infections.

Intensive care unit-acquired (ICU-acquired) bloodstream infections (BSI) are an important complication of critical illness. The objective of this study was to quantify the excess length of stay, mortality and cost attributable to ICU-acquired BSI. A matched cohort study was conducted in all adult ICUs in the Calgary Health Region between 1 May 2000 and 30 April 2003. One hundred and forty-four patients with ICU-acquired BSI were matched (1:1) to patients without ICU-acquired BSI. Patients with ICU-acquired BSI had a significantly increased median length of ICU stay {15.5 [interquartile range (IQR) 8-26] days vs 12 [IQR 7-18.5] days, P=0.003} and median costs of hospital care [85,137 dollars (IQR 45,740-131,412 dollars) vs 67,879 dollars (IQR 35,043-115,915 dollars, P=0.02) compared with patients without ICU-acquired BSI. The median excess length of ICU stay was two days and the median cost attributable to ICU-acquired BSI was 12,321 dollars per case. Sixty (42%) of the cases died compared with 37 (26%) of the controls [P=0.002, attributable mortality 16%, 95% confidence interval (CI) 5.9-26.0%]. Patients with ICU-acquired BSI were at increased risk for in-hospital death (odds ratio=2.64, 95%CI 1.40-5.29). Among survivor-matched pairs, the median excess lengths of ICU and hospital stay attributable to development of ICU-acquired BSI were two and 13.5 days, respectively, and the attributable cost due to ICU-acquired BSI was 25,155 dollars per case survivor. Critically ill patients who develop ICU-acquired BSI suffer excess morbidity and mortality, and incur significantly increased healthcare costs. These data support expenditures on infection prevention and control programmes and further research into reducing the impact of these infections.

Aged↗
PubMed2006

Population-based surveillance of invasive pyogenic streptococcal infection in a large Canadian region.

Pyogenic streptococci are a major cause of invasive infection. This study presents the results of a population-based laboratory surveillance for invasive pyogenic streptococcal infections among residents of the Calgary Health Region (population 1 million) between 1 July 1999 and 30 June 2004. The overall annual incidence rate was 18.65/100,000 population, with isolates belonging to the Streptococcus milleri group forming the most important aetiology (incidence of 8.65/100,000 population). Invasive infection with groups A, B, G and C streptococci occurred at annual rates of 4.27, 3.13, 1.83 and 0.41/100,000 population, respectively. There was a close relationship between increasing age and development of an invasive pyogenic streptococcal infection, and the incidence of infection was higher among males than among females. Differences in the seasonal occurrence and focus of infection occurred between the different groups.

Adolescent↗
PubMed2004

Intensive-care-unit-acquired bloodstream infections in a regional critically ill population.

Bloodstream infection (BSI) is a serious complication of critical illness but it is uncertain whether acquisition of BSI in the intensive care unit (ICU) increases the risk of death. A study was conducted among all Calgary health region (population approximately 1 million) adults admitted to ICUs for 48 h or more during a three-year period to investigate the occurrence, microbiology and risk factors for developing an ICU-acquired BSI and to determine whether these infections independently predict mortality. One hundred and ninety-nine ICU-acquired BSI episodes occurred during 4933 ICU admissions for a cumulative incidence of 4% and an incidence density of 5.4 per 1000 ICU days. The most common isolates were Staphylococcus aureus (18%), coagulase-negative staphylococci (11%), and Enterococcus faecalis (8%); 12% of infections were due to antimicrobial-resistant bacteria. Admission to the regional neurosurgery/trauma ICU [odds ratio (OR) 2.86; 95% confidence interval (CI) 2.10-3.90] and increasing Acute Physiology and Chronic Health Evaluation II (APACHE II) score (OR 1.05 per point, 95% CI 1.03-1.07) were associated with higher risk, whereas a surgical diagnosis (OR 0.69; 95% CI 0.52-0.93) was associated with lower risk of developing ICU-acquired BSI in logistic regression analysis. The crude in-hospital death rate was 45% for patients with ICU-acquired BSI compared with 21% for those without (P < 0.0001) Development of an ICU-acquired BSI was an independent risk factor for death (OR 1.79; 95% CI 1.3-2.5) and increases the risk of dying from critical illness.

APACHE↗
PubMed2004

New method for laboratory detection of AmpC beta-lactamases in Escherichia coli and Klebsiella pneumoniae.

A new cefoxitin-agar medium (CAM)-based assay was compared to the previously published modified three-dimensional (M3D) assay for the detection of AmpC production in Escherichia coli and Klebsiella pneumoniae. Clinical isolates of cefoxitin-resistant E. coli (n = 5) and K. pneumoniae (n = 7) and multiple control strains with and without AmpC enzymes were tested by both methods. The CAM method with 4 microg of cefoxitin/ml was equivalent to the M3D method for detecting AmpC production in E. coli and K. pneumoniae. This new method is easier to perform and interpret and allows for testing of multiple isolates on a single plate.

Agar↗
PubMed2000

Hospital- and community-based surveillance of methicillin-resistant Staphylococcus aureus: previous hospitalization is the major risk factor.

OBJECTIVE: The purpose of the study was to determine the incidence and risk factors for the acquisition of methicillin-resistant Staphylococcus aureus (MRSA) in our community. DESIGN: This study used a cross-sectional design to assess patients colonized or infected with MRSA. PATIENTS: The study population consisted of residents of London, Ontario, Canada, who were identified as MRSA-positive for the first time in 1997. SETTING: All acute- and chronic-care hospitals, long-term healthcare facilities, and community physicians' offices in the city of London participated in the study. MAIN OUTCOME MEASURE: Incidence of MRSA in the community, risk factors for acquisition, especially previous hospitalization over a defined period, and strain type were evaluated. RESULTS: In 1997, 331 residents of London were newly identified as MRSA-positive, representing an annual incidence of 100/100,000 persons (95% confidence interval, 88.8-110.7). Thirty-one (9.4%) individuals were not healthcare-facility patients in the previous month, and 11 (3.3%), 10 (3.0%), and 6 (1.8%) individuals had no such contact in the previous 3, 6, and 12 months, respectively. One hundred seventy-seven strains, including five of the isolates from patients with no healthcare-facility contact in the previous year, were typed. One hundred sixty (90.3%) of these isolates, including all typed strains from patients with no healthcare facility contact, belonged to a single clone. CONCLUSION: These findings demonstrate that the incidence of MRSA is higher than previously reported and that hospital contact is the single most important risk factor for the acquisition of MRSA in our community. Screening for MRSA in previously hospitalized patients at the time of hospitalization may reduce nosocomial spread and indirectly reduce the incidence of MRSA in the community.

Adult↗
PubMed1989

The prevalence of Campylobacter pylori gastritis among asymptomatic adults.

To determine the prevalence of Campylobacter pylori colonization in the healthy population we studied 54 asymptomatic volunteers and 65 patients referred because of gastrointestinal symptoms. All subjects underwent gastroscopy and gastric biopsy. C. pylori was isolated from 6 volunteers (11%) and 36 patients (55%). Histologic evidence of inflammation was present in 98% of the culture-positive subjects. Linear regression analysis revealed that the prevalence of C. pylori colonization increased with age. There was no difference in the isolation rate between the two groups when adjusted for age. Four of the six culture-positive volunteers underwent repeat endoscopy and gastric biopsy 1 year later; despite remaining asymptomatic, all still had positive culture results and histologic evidence of gastritis. We conclude that the prevalence of C. pylori-associated gastritis among symptomatic patients increases with age and that the organism may be present in the gastrointestinal tract for prolonged periods without symptoms or evidence of disease progression.

Adult↗
PubMed1988

Problems with rapid agglutination methods for identification of Staphylococcus aureus when Staphylococcus saprophyticus is being tested.

Six rapid agglutination tests for identification of Staphylococcus aureus were evaluated by using 62 strains of S. aureus, 63 strains of S. saprophyticus, and 67 strains of other coagulase-negative staphylococci. S. saprophyticus was responsible for 19 of 26 false-positive results and 20 uninterpretable reactions. Thus, urinary staphylococcal isolates that are positive by rapid agglutination tests may require other confirmatory tests for the identification of possible S. saprophyticus.

Hemagglutination Tests↗