CANWARD symposium
Prevalence of antimicrobial resistant pathogens from blood cultures from Canadian hospitals: results of the CANWARD 2007–2009 study

https://doi.org/10.1016/j.diagmicrobio.2010.10.026Get rights and content

Abstract

This study assessed the epidemiology and antimicrobial resistance of pathogens associated with bloodstream infections in Canadian hospitals between 2007 and 2009. Tertiary-care medical centers representing 8 of 10 Canadian provinces submitted bloodstream infection pathogens from patients attending hospital clinics, emergency rooms, medical/surgical wards, and intensive care units. Over 8,000 blood culture pathogens were collected. The 10 most common pathogens (representing 80.9% of all isolates) were Escherichia coli (1856 [22.6%]), Staphylococcus aureus (1457 [17.7%] including 1101 methicillin-susceptible Staphylococcus aureus and 356 methicillin-resistant Staphylococcus aureus), coagulase-negative staphylococci (907 [11.0%]), Klebsiella pneumoniae (600 [7.3%]), Streptococcus pneumoniae (470 [5.7%]), Enterococcus faecalis (360 [4.4%]), Pseudomonas aeruginosa (333 [4.0%]), viridans group streptococci (321 [3.9%]), Enterobacter cloacae (193 [2.3%]), and Streptococcus pyogenes (159 [1.9%]). The most active agents against Gram-negative bacilli were carbapenems (e.g., meropenem and ertapenem) and piperacillin-tazobactam, while for Gram-positive cocci, they were vancomycin, linezolid, and daptomycin.

Introduction

Bloodstream infections cause significant morbidity and mortality and result in substantial health care costs. Recent studies in the United States and England indicate a high incidence of bloodstream infections (200 000 cases per year in the United States; 189 cases per 100 000 population in England), with the highest burden observed in patients over 74 years of age (857 cases per 100 000 population) (Reimer et al., 1997, Wilson et al., 2010). Reported mortality rates range between 18% and 60% and vary based on a number of factors, including the causative agent (Reimer et al., 1997; Sligl et al., 2006).

Empiric antimicrobial therapy is commonly administered early in the course of bloodstream infections (Munson et al., 2003). The epidemiology of bloodstream infections and the antimicrobial susceptibility patterns of the causative agents vary over time (Decousser et al., 2009, Wilson et al., 2010). National surveillance studies that monitor the prevalence of pathogens and their antimicrobial susceptibility patterns are essential to determine appropriate empiric therapy (Decousser et al., 2009). This study assessed the epidemiology and antimicrobial resistance of pathogens associated with bloodstream infections in Canadian hospitals.

Section snippets

Isolates

Study isolates were obtained as part of the annual, ongoing Canadian Ward Surveillance Study (CANWARD) from 2007 to 2009, as previously described in this symposium (Zhanel et al., 2011). Of the 18 538 isolates collected throughout the study, 8228 (44.4%) were blood culture pathogens. Each month, the first 15–30 (2007: 30; 2008: 20; 2009: 15) clinically significant blood culture isolates were included in the study to assess the causes of bloodstream infections throughout the entire year, thereby

Demographics of the patients with bloodstream infections in CANWARD 2007–2009

Of the 8228 blood culture pathogens collected between 2007 and 2009 for which complete data were available, 4749 (57.7%) were received from males. There were 872 (10.6%), 3881 (47.2%), and 3475 (42.2%) isolates received from patients 0–17, 18–64, and ≥65 years of age, respectively. The geographical locations of the referring centers were as follows: 1495 (18.2%) from British Columbia/Alberta, 1484 (18.0%) from Manitoba/Saskatchewan, 2235 (27.2%) from Ontario, 2189 (26.6%) from Quebec, and 825

Discussion

Between 2007 and 2009, more than 8000 blood culture pathogens were studied as part of CANWARD. Most of the bloodstream infection pathogens were received from males (57.7%) and patients greater than 17 years of age (89.4%). The association of a greater incidence of bloodstream infections among males has been noted previously (Sligl et al., 2006, Wilson et al., 2010). Similarly, other recent studies have also revealed that the smallest percentage of blood culture isolates is received from

Acknowledgments

Funding and medical center (investigator) acknowledgements are provided in the first paper of this symposium (Hoban and Zhanel, 2011).

CANWARD data can also be found at www.can-r.ca, the official website of the Canadian Antimicrobial Resistance Alliance (CARA).

References (16)

There are more references available in the full text version of this article.

Cited by (35)

  • Staphylococcal Infections

    2022, Greene's Infectious Diseases of the Dog and Cat, Fifth Edition
  • Bacterial and fungal pathogens isolated from patients with bloodstream infection: frequency of occurrence and antimicrobial susceptibility patterns from the SENTRY Antimicrobial Surveillance Program (2012–2017)

    2020, Diagnostic Microbiology and Infectious Disease
    Citation Excerpt :

    Surveillance programs help guide clinicians to choose appropriate empirical therapy for patients suspected to have BSI by defining species distribution of pathogens and their resistance patterns. As a result, antimicrobial resistance surveillance programs have proliferated over the past 2 decades (Adam et al., 2011; Ammerlaan et al., 2013; Fuhrmeister and Jones, 2019; Langley et al., 2015; Nunez-Nunez et al., 2018; Rello et al., 2019; Sader et al., 2019; Sirijatuphat et al., 2018; Wisplinghoff et al., 2004). These programs provided useful information regarding pathogen distribution and resistance trends from a wide variety of infection sites (Diekema, et al., 2002; Fuhrmeister and Jones, 2019; Langley et al., 2015; Rello et al., 2019; Weiner et al., 2016).

  • Multifaceted antibiotic treatment analysis of methicillin-sensitive Staphylococcus aureus bloodstream infections

    2016, International Journal of Antimicrobial Agents
    Citation Excerpt :

    Staphylococcus aureus is an important cause of bloodstream infection (BSIs) and associated complications. It was the second most common pathogen found in more than 8,000 positive blood cultures in Canadian hospitals in the CANWARD 2007–2009 study [1]. A population surveillance study of S. aureus bloodstream infections (SA-BSIs) in Australia, Canada, Denmark, Finland and Sweden reported an overall incidence rate of 26.1 cases per 100,000 population, characterised by 24.2 cases of methicillin-sensitive S. aureus (MSSA) and 1.9 cases of methicillin-resistant S. aureus (MRSA) infections [2].

  • Incidence, risk factors, and outcomes for Enterococcus spp. blood stream infections: A population-based study

    2014, International Journal of Infectious Diseases
    Citation Excerpt :

    Twenty-five percent of enterococcal BSIs acquired in the nosocomial setting are due to E. faecium, comparable to 14-37% in prior studies2,5,7,10,14,15. We report higher vancomycin resistance rates than previously suggested in CHZ in 1999 (1.3%)5, but similar to a more recent Canadian study by Adam et al (4.6%)6. Our rates of vancomycin resistance were low compared to reports from the United Kingdom13, and significantly lower than what has been reported in India and the United States, where >10% of E. faecalis isolates and >80% of E. faecium isolates are resistant to vancomycin1,5,15,47.

  • Other β-Lactam Antibiotics

    2014, Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases
View all citing articles on Scopus
View full text