Canadian Nosocomial Infection Surveillance Program: Antimicrobial resistance in Canadian hospitals

Abstract

Surveillance is essential to inform evidence-based policy and control measures that combat antimicrobial resistance (AMR). The Canadian Nosocomial Infection Surveillance Program (CNISP) collaborates with 88 sentinel hospitals across Canada to conduct prospective surveillance of infections and antimicrobial resistant organisms important to hospital infection prevention and control. This article aims to increase awareness of CNISP hospital-based surveillance activities. Since its inception in 1995, the scope of CNISP has expanded to include community-associated infections, outpatient Clostridioides difficile infections, viral respiratory infections such as coronavirus disease 2019, and emerging pathogens such as Candida auris. This change in scope, along with expansion to include rural, northern and community hospitals, has improved the generalizability of CNISP surveillance data. To generate actionable surveillance data, CNISP integrates demographic and clinical data abstracted from patient charts with molecular and microbiological data abstracted from laboratory testing. These data serve as a benchmark for participating hospitals and stakeholders to assess the burden of AMR in hospital and intervene as needed. Further, CNISP surveillance data are now available on a public-facing data blog that provides interactive visualizations and data syntheses sooner than peer-reviewed publications. Future directions of CNISP include the Simplified Dataset, which will capture aggregate AMR data from hospitals outside of the CNISP network, surveillance in long-term care facilities and a fourth point prevalence survey. Given its strengths and future directions, CNISP is well positioned to serve as the reference point for hospital-based AMR data in Canada.

Introduction

Antimicrobial resistance (AMR) is a threat to global public health. Surveillance is an essential pillar of the World Health Organization global action plan to combat AMR and a key component of the Pan-Canadian Framework for Action, which provides the context and foundation to guide a pan-Canadian response to combat AMR ^{Footnote 1 Footnote 2}. Both community and hospital-based surveillance are needed to inform evidence-based action, such as antimicrobial stewardship ^{Footnote 3}. We provide an overview of the Canadian Nosocomial Infection Surveillance Program (CNISP)—a hospital-based surveillance system. In describing its scope, functions and future directions, we aim to increase awareness of the CNISP hospital-based surveillance activities that contribute to combatting AMR in Canada.

Structure

Prompted by a World Health Organization recommendation focused on combatting AMR, Health Canada established and fully funded CNISP as a hospital-based surveillance system in 1995. CNISP is a collaboration between the Public Health Agency of Canada, including the National Microbiology Laboratory, the Association of Medical Microbiology and Infectious Disease Canada and sentinel hospitals across Canada.

Scope

In 1995, CNISP conducted active surveillance in 18 hospitals across seven provinces and reported on only one antibiotic-resistant organism (ARO): methicillin-resistant Staphylococcus aureus (MRSA). By 2022, CNISP has expanded to conduct surveillance on 12 different pathogens in 88 hospitals across 10 provinces and 1 territory. Figure 1 presents the complete list of pathogens CNISP conducts surveillance on, which includes healthcare-associated infections and AROs, along with the year surveillance of each started. CNISP also annually collects and analyzes data from Canadian hospitals on antimicrobial use (AMU), antibiogram, infection prevention and control (IPC) practises, laboratory practises and viral respiratory illness including coronavirus disease 2019 (COVID-19). Figure 2 presents the geographical distribution and characteristics of hospitals across Canada participating in CNISP surveillance in 2022.

Figure 1 - Text description

This figure shows the increase in Canadian Nosocomial Infection Surveillance Program (CNISP) surveillance activities and participating hospitals between 1995 and 2022. In 1995, CNISP started surveillance of methicillin-resistant Staphylococcus aureus bloodstream infections (MRSA BSI). In 1999, CNISP started surveillance of vancomycin-resistant Enterococcus (VRE) BSI. In 2000, CNISP started surveillance of cerebrospinal fluid (CSF) shunt surgical site infections (SSI). In 2006, CNISP started surveillance of central line-associated blood stream infections (CLABSI). In 2007, CNISP started surveillance of Clostridium difficile infection (CDI). In 2009, CNISP started collecting antimicrobial use data from participating hospital pharmacies. In 2010, CNISP started surveillance of carbapenemase-producing organisms (Enterobacterales and Acinetobacter), and paediatric cardiac SSI. In 2011, CNISP started surveillance of hip and knee SSI. In 2015, CNISP expanded CDI surveillance to included community-associated, recurrent and outpatient CDI infections. In 2017, CNISP started surveillance of methicillin-susceptible Staphylococcus aureus (MSSA) BSI and collecting antibiogram data. In 2019, CNISP started surveillance of Candida auris and viral respiratory illness, including COVID-19. In 2022, CNISP started surveillance pilots for adult cardiac SSI and the CDI simplified dataset. CNISP conducted periodic point prevalence surveys of healthcare-associated infections in 2002, 2009 and 2017. CNISP will conduct a fourth point prevalence survey in 2023. The number of hospitals participating in CNISP increased between 1995 and 2022: 18 in 1995, 39 in 2003, 52 in 2011, 78 in 2019 and 88 in 2022.

Figure 2 - Text description

Hospital name	Province	City	Facility type	Bed category
Peter Lougheed Centre	Alberta	Calgary	Adult/Mixed	500+ beds
Rockyview General Hospital	Alberta	Calgary	Adult/Mixed	500+ beds
South Health Campus	Alberta	Calgary	Adult/Mixed	201–499 beds
Foothills Medical Centre	Alberta	Calgary	Adult/Mixed	500+ beds
University of Alberta Hospital	Alberta	Edmonton	Adult/Mixed	500+ beds
Alberta Children's Hospital	Alberta	Calgary	Paediatric	1–200 beds
Stollery Children's Hospital	Alberta	Edmonton	Paediatric	1–200 beds
Vancouver General Hospital (VGH)	British Columbia	Vancouver	Adult/Mixed	500+ beds
Richmond General Hospital	British Columbia	Richmond	Adult/Mixed	201–499 beds
UBC Hospital	British Columbia	Kelowna	Adult/Mixed	201–499 beds
Lion's Gate Hospital	British Columbia	North Vancouver	Adult/Mixed	500+ beds
Powell River General Hospital	British Columbia	Powell River	Adult/Mixed	1–200 beds
Sechelt Hospital (formerly St. Mary's)	British Columbia	Sechelt	Adult/Mixed	1–200 beds
Squamish General Hospital	British Columbia	Squamish	Adult/Mixed	1–200 beds
Victoria General Hospital	British Columbia	Victoria	Adult/Mixed	201–499 beds
Royal Jubilee Hospital	British Columbia	Victoria	Adult/Mixed	201–499 beds
Nanaimo Regional General Hospital	British Columbia	Nanaimo	Adult/Mixed	201–499 beds
BC Women's Hospital	British Columbia	Vancouver	Adult/Mixed	201–499 beds
Kelowna General Hospital	British Columbia	Kelowna	Adult/Mixed	201–499 beds
Penticton Regional Hospital	British Columbia	Penticton	Adult/Mixed	1–200 beds
University Hospital of Northern BC	British Columbia	Prince George	Adult/Mixed	201–499 beds
BC Children's Hospital	British Columbia	Vancouver	Paediatric	201–499 beds
Health Sciences Centre-Winnipeg	Manitoba	Winnipeg	Adult/Mixed	500+ beds
University of Manitoba Children's Hospital	Manitoba	Winnipeg	Paediatric	1–200 beds
The Moncton Hospital	New Brunswick	Moncton	Adult/Mixed	201–499 beds
General Hospital & Miller Centre	Newfoundland and Labrador	St. John's	Adult/Mixed	201–499 beds
Burin Peninsula Health Care Centre	Newfoundland and Labrador	Burin	Adult/Mixed	1–200 beds
Carbonear General Hospital	Newfoundland and Labrador	Carbonear	Adult/Mixed	1–200 beds
Dr. G.B. Cross Memorial Hospital	Newfoundland and Labrador	Clarenville	Adult/Mixed	1–200 beds
St. Clare's Mercy Hospital	Newfoundland and Labrador	St. John's	Adult/Mixed	1–200 beds
Western Memorial Regional Hospital	Newfoundland and Labrador	Corner Brook	Adult/Mixed	201–499 beds
Sir Thomas Roddick Hospital	Newfoundland and Labrador	Stephenville	Adult/Mixed	1–200 beds
Central Newfoundland Regional Health Centre	Newfoundland and Labrador	Grand Falls-Windsor	Adult/Mixed	1–200 beds
James Paton Memorial Hospital	Newfoundland and Labrador	Gander	Adult/Mixed	1–200 beds
Dr. Y.K.Jeon Kittiwake Health Centre	Newfoundland and Labrador	New-Wes-Valley	Adult/Mixed	1–200 beds
Fogo Island Health Centre	Newfoundland and Labrador	Fogo	Adult/Mixed	1–200 beds
Notre Dame Bay Memorial Health Centre	Newfoundland and Labrador	Twillingate	Adult/Mixed	1–200 beds
Connaigre Peninsula Health Centre	Newfoundland and Labrador	Harbour Breton	Adult/Mixed	1–200 beds
Green Bay Health Centre	Newfoundland and Labrador	Springdale	Adult/Mixed	1–200 beds
Baie Verte Peninsula Health Centre	Newfoundland and Labrador	Baie Verte	Adult/Mixed	1–200 beds
Janeway Children's Hospital and Rehabilitation Centre	Newfoundland and Labrador	St. John's	Paediatric	1–200 beds
A.M. Guy Health Centre	Newfoundland and Labrador	Buchans	Adult/Mixed	1–200 beds
Halifax Infirmary	Nova Scotia	Halifax	Adult/Mixed	500+ beds
Victoria General	Nova Scotia	Halifax	Adult/Mixed	500+ beds
Rehabilitation Centre	Nova Scotia	Halifax	Adult/Mixed	500+ beds
Veterans Memorial Building	Nova Scotia	Halifax	Adult/Mixed	500+ beds
Dartmouth General Hospital	Nova Scotia	Halifax	Adult/Mixed	500+ beds
IWK Health Centre	Nova Scotia	Halifax	Adult/Mixed	1–200 beds
Qikiqtani General Hospital	Nunavut	Iqaluit	Adult/Mixed	1–200 beds
Victoria Hospital	Ontario	London	Adult/Mixed	201–499 beds
University Hospital	Ontario	London	Adult/Mixed	500+ beds
Toronto General Hospital	Ontario	Toronto	Adult/Mixed	201–499 beds
Toronto Western Hospital	Ontario	Toronto	Adult/Mixed	201–499 beds
Princess Margaret Hospital	Ontario	Toronto	Adult/Mixed	201–499 beds
Mount Sinai Hospital	Ontario	Toronto	Adult/Mixed	201–499 beds
Hennick Bridgepoint Hospital	Ontario	Toronto	Adult/Mixed	201–499 beds
Sunnybrook Hospital	Ontario	Toronto	Adult/Mixed	500+ beds
Kingston General Hospital	Ontario	Kingston	Adult/Mixed	201–499 beds
McMaster Children's Hospital	Ontario	Hamilton	Adult/Mixed	201–499 beds
St Joseph's Healthcare	Ontario	Hamilton	Adult/Mixed	500+ beds
Jurvinski Hospital and Cancer Center	Ontario	Hamilton	Adult/Mixed	201–499 beds
HHS General Site	Ontario	Hamilton	Adult/Mixed	500+ beds
The Ottawa Hospital Civic Campus	Ontario	Ottawa	Adult/Mixed	500+ beds
The Ottawa Hospital General Campus	Ontario	Ottawa	Adult/Mixed	500+ beds
University of Ottawa Heart Institute	Ontario	Ottawa	Adult/Mixed	1–200 beds
North York General Hospital	Ontario	North York	Adult/Mixed	201–499 beds
St. Michael's Hospital	Ontario	Toronto	Adult/Mixed	201–499 beds
Sudbury Regional Hospital	Ontario	Sudbury	Adult/Mixed	201–499 beds
Children's Hospital of Western Ontario	Ontario	London	Paediatric	1–200 beds
The Hospital for Sick Children	Ontario	Toronto	Paediatric	201–499 beds
Children's Hospital of Eastern Ontario (CHEO)	Ontario	Ottawa	Paediatric	1–200 beds
Queen Elizabeth Hospital	Prince Edward Island	Charlottetown	Adult/Mixed	201–499 beds
Prince County Hospital	Prince Edward Island	Summerside	Adult/Mixed	1–200 beds
SMBD - Jewish General Hospital	Québec	Montréal	Adult/Mixed	500+ beds
Hôpital Maisonneuve-Rosemont	Québec	Montréal	Adult/Mixed	500+ beds
Hôtel-Dieu de Québec	Québec	Québec City	Adult/Mixed	201–499 beds
Montreal General Hospital	Québec	Montréal	Adult/Mixed	201–499 beds
Royal Victoria Hospital	Québec	Montréal	Adult/Mixed	201–499 beds
Montreal Neurological Institute	Québec	Montréal	Adult/Mixed	1–200 beds
Lachine General Hospital	Québec	Lachine	Adult/Mixed	1–200 beds
CHU Sainte-Justine	Québec	Montréal	Adult/Mixed	201–499 beds
Centre hospitalier de l'Université de Montréal (CHUM)	Québec	Montréal	Adult/Mixed	500+ beds
Montreal Children's Hospital	Québec	Montréal	Paediatric	1–200 beds
Royal University Hospital	Saskatchewan	Saskatoon	Adult/Mixed	201–499 beds
St. Paul's Hospital	Saskatchewan	Saskatoon	Adult/Mixed	201–499 beds
Regina General Hospital	Saskatchewan	Regina	Adult/Mixed	201–499 beds
Pasqua Hospital	Saskatchewan	Regina	Adult/Mixed	201–499 beds
Moose Jaw Hospital	Saskatchewan	Moose Jaw	Adult/Mixed	1–200 beds

The expansion of CNISP to include rural, northern and community hospitals has improved the generalizability of its hospital-based surveillance data. As of 2022, one-third of CNISP participating hospitals (n=28/88, 32%) are non-teaching hospitals in the community, as defined by the Canadian Institute for Health Information ^{Footnote 4}. Further, the number of beds across the 88 hospitals participating in CNISP surveillance in 2022 ranged from 3 to 1,087 and 1 of 3 territories are represented. In addition to improvements in CNISP representativeness, the scope of CNISP has expanded. CNISP began collecting data on community-associated (CA) MRSA in 2010 and has since expanded to collect data on CA infections (e.g. CA Clostridioides difficile infections; CDI) and AROs (e.g. CA carbapenemase-producing Enterobacterales; CPE). Other areas in which CNISP has expanded its scope is with surveillance of outpatient CDI and emerging pathogens such as Candida auris.

Functions

Collect and analyze data

CNISP is the only national hospital sentinel system in Canada that actively collects AMR data via standardized methods. Definitions and protocols, which are publicly available online, facilitate this standardized data collection. CNISP analyzes demographic and clinical data abstracted from patient charts by trained IPC professionals, with linked molecular and microbiological data abstracted from centralized laboratory testing conducted by the National Microbiology Laboratory. A major strength of CNISP, relative to other surveillance systems, is its integration of these data. This comprehensive dataset has been essential in the monitoring of emerging AMR pathogens, including, for example, the hyper virulent C. difficile NAP1 (rt027) strain type, the emergence of CA-MRSA strain types (CMRSA10/USA300 and CMRSA7/USA400), vancomycin-resistant Enterococci (VRE) sequence type 1478 and CPE ^{Footnote 5 Footnote 6 Footnote 7 Footnote 8 Footnote 9}.

Provide benchmarks

A key function of CNISP is to provide participating hospitals and knowledge users, such as IPC and antimicrobial stewardship professionals, with benchmarks for hospital-acquired infection, ARO and AMU rates. By comparing their own site-specific rates to regional and national rates, participating hospitals can assess their progress in AMR prevention and intervene as needed. To facilitate this for selected surveillance projects, such as AMU, CNISP has developed and automated a site-specific report that presents site-specific rates relative to the rates of comparable hospitals in the CNISP network (de-identified in the site-specific report). In addition, participating hospitals have access to visual analytics for CDI on the Canadian Network for Public Health Intelligence platform, the secure on-line platform where hospitals submit their data. The Canadian Network for Public Health Intelligence visual analytics offers CNISP hospitals the ability to compare their rates of CDI to hospitals similar in size, type (community vs. teaching) or services offered, and to regional, provincial and national rates. Hospitals can also view resistance profiles and molecular characteristics (e.g. ribotypes). Antimicrobial stewardship groups, administrators and IPC staff may further benefit by utilizing these hospital-based surveillance data to guide quality improvement initiatives that tackle AMR, such as reducing AMU or implementing bundled interventions to reduce the risk of infection.

Disseminate scientific evidence

Since 1995, in collaboration with the National Microbiology Laboratory and stakeholders from participating hospitals, CNISP has produced over 260 publications, including peer-reviewed articles, reports and conference abstracts. These provide scientific evidence to inform public health action to reduce AMR. CNISP annually publishes reports summarizing trends in healthcare-associated infections and AMR in the Canada Communicable Disease Report and on the Government of Canada website. To improve accessibility and uptake of CNISP surveillance data among the public and healthcare professionals outside of the CNISP network, in 2022, CNISP launched an interactive data blog on the Government of Canada website. These data are consistent with those reported in the Canada Communicable Disease Report and additionally include data pertaining to AMU in hospitals, demonstrating CNISP's progress towards achieving integrated AMR/AMU surveillance across Canadian hospitals. This publicly available interface provides timely data syntheses and interactive visualizations to inform strategies to combat AMR sooner than peer-reviewed publications.

Guide policy and practice

CNISP surveillance data informs evidence-based policy and guidelines within Canada and internationally. For example, the Manitoba provincial government applies CNISP standardized definitions in their CDI clinical management protocol ^{Footnote 10}. Further, CNISP hospital-based surveillance informed provincial guidelines for the prevention and control of AROs ^{Footnote 11}. The CNISP supports the collaborative work plan of the Public Health Agency of Canada as demonstrated by its international partnerships with the Transatlantic Taskforce on Antimicrobial Resistance and the World Health Organization Global Antimicrobial Resistance and Use Surveillance System. CNISP provides antibiogram data to the Global Antimicrobial Resistance and Use Surveillance System for incorporation into their international database and report, which provide insights into the global burden of AMR ^{Footnote 12}. In addition, CNISP contributes hospital-based AMR data to the Canadian Antimicrobial Resistance Surveillance System annual report, which presents human data from CNISP with data from the animal, environmental and food safety sectors ^{Footnote 13}.

Adapt to public health needs

At the start of the COVID-19 pandemic, CNISP leveraged its existing network of sentinel hospitals across Canada to expand the scope of its viral respiratory illness surveillance to include CA and healthcare-associated COVID-19. CNISP participating hospitals collect COVID-19 patient level data, including demographic, clinical, outcome, AMU and ARO co-infection data. Using these patient level data, CNISP published a peer-reviewed article describing the epidemiology of patients with COVID-19 admitted to CNISP participating hospitals ^{Footnote 14}. Currently, CNISP is analyzing the impact of COVID-19 on ARO rates calculated from CNISP hospital-based surveillance data to better understand how the burden of AMR in hospitals has changed in Canada. CNISP also demonstrated its adaptability to respond to new and emerging pathogens by way of its initiation of C. auris surveillance in 2019. Since then, CNISP has contributed to understanding the prevalence of C. auris in Canadian acute-care hospitals and preparedness for C. auris in CNISP participating hospitals ^{Footnote 15 Footnote 16}.

Discussion

For more than 20 years, CNISP has been a successful collaboration between the federal government, national organizations and sentinel hospitals across Canada. In the future, CNISP will seek to recruit hospitals from the Northwest Territories and provinces with currently low representation. To further increase participation and improve the representativeness of its hospital-based surveillance data, CNISP has launched a Simplified Dataset (SDS). The SDS uses CNISP standardized definitions and aims to capture data on healthcare-associated infections and AROs from acute-care hospitals outside of the CNISP network. While hospitals participating in CNISP active surveillance submit patient-level data, hospitals participating in the SDS submit aggregate data (annual number of cases, patient days and patient admissions). In combining both data sources, CNISP will be able to report national and regional rates of AMR from a greater number and more representative sample of Canadian hospitals. After successful pilot testing of the SDS for CDI surveillance, CNISP is seeking to recruit additional hospitals outside of the network to participate in the SDS for CDI surveillance.

To further describe the burden of AMR in Canadian hospitals, CNISP will be conducting a point prevalence survey in 2023, which aims to include acute-care hospitals within and outside of the CNISP network. This survey will build upon three-point prevalence surveys conducted in 2002, 2009 and 2017 by CNISP. For Canadian hospitals, these repeated surveys are widely utilized to benchmark hospital-acquired infection, ARO and AMU rates, measure changes in prevalence over time, provide information on AMR control programs and identify new targets for surveillance ^{Footnote 17 Footnote 18 Footnote 19}. CNISP also seeks to expand its use of whole-genome sequencing to enable a deeper analysis of the evolving molecular epidemiology and transmission of AMR pathogens in Canada. Data from whole-genome sequencing can support IPC and stewardship practises in hospitals, and ultimately enhance public health interventions for AMR and infectious diseases ^{Footnote 20}.

Because CNISP is a hospital-based surveillance system, its AMR and AMU data are not generalizable to settings such as primary and long-term care. To improve our understanding of AMR in Canada, future surveillance efforts should focus on ascertaining AMR and AMU data from these under-represented settings ^{Footnote 3 Footnote 21}. While CNISP captures data on CDI in outpatient settings and CA AROs, such as CA MRSA, CA CPE, CA VRE and CA CDI, there remains an important gap in our understanding of AMR and AMU in community settings ^{Footnote 3 Footnote 21}. To help address this, future expansion of CNISP also includes the initiation of AMR surveillance in long-term care. The scope and methodology for long-term care surveillance are currently under development.

Conclusion

Supported by the federal government, CNISP is a core national program that has monitored AMR in Canadian acute-care hospitals since 1995. Surveillance data from this network of urban and community hospitals across Western, Central, Eastern and Northern Canada is used to provide benchmarks and inform evidence-based action, such as antimicrobial stewardship. Given its achievements in recent years and future directions, CNISP is well positioned to serve as the reference point for hospital-based AMR data in Canada.

Authors' statement

Epidemiologists from Public Health Agency of Canada were responsible for the conception, interpretation, drafting and revision of the article. The National Microbiology Laboratory and CNISP co-chairs contributed to the interpretation and revision of the paper.

Competing interests

None.

Acknowledgements

We gratefully acknowledge the contribution of the physicians, epidemiologists, infection control practitioners and laboratory staff at each participating hospital: Vancouver General Hospital (VGH), Vancouver, British Columbia (BC); Richmond General Hospital, Richmond, BC; UBC Hospital, Vancouver, BC; Lion's Gate, North Vancouver, BC; Powell River General Hospital, Powell River, BC; Sechelt Hospital (formerly St. Mary's), Sechelt, BC; Squamish General Hospital, Squamish, BC; BC Children's Hospital, Vancouver, BC; Peter Lougheed Centre, Calgary, Alberta (AB); Rockyview General Hospital, Calgary, AB; South Health Campus, Calgary, AB; Foothills Medical Centre, Calgary, AB; Alberta Children's Hospital, Calgary, AB; University of Alberta Hospital, Edmonton, AB; Stollery Children's Hospital, Edmonton, AB; Health Sciences Centre-Winnipeg, Winnipeg, Manitoba (MB); University of Manitoba Children's Hospital, Winnipeg, MB; Children's Hospital of Western Ontario, London, Ontario (ON); St. Michael's Hospital, Toronto, ON; Victoria Hospital, London, ON; University Hospital, London, ON; Toronto General Hospital, Toronto, ON; Toronto Western Hospital, Toronto, ON; Princess Margaret, Toronto, ON; Mount Sinai Hospital, Toronto, ON; Bridgepoint Active Healthcare, Toronto, ON; Sunnybrook Hospital, Toronto, ON; Kingston General Hospital, Kingston, ON; SMBD - Jewish General Hospital, Montréal, Québec (QC); Lachine General Hospital, Lachine, QC; The Moncton Hospital, Moncton, New Brunswick (NB); Halifax Infirmary, Halifax, Nova Scotia (NS); Victoria General, Halifax, NS; Rehabilitation Centre, Halifax, NS; Veterans Memorial Building, Halifax, NS; Dartmouth General Hospital, Halifax, NS; IWK Health Centre, Halifax, NS; Hospital for Sick Children, Toronto, ON; Montréal Children's Hospital, Montréal, QC; Royal University Hospital, Saskatoon, Saskatchewan (SK); Moose Jaw Hospital, SK; St. Paul's Hospital, Saskatoon, SK; General Hospital & Miller Centre, St. John's, Newfoundland and Labrador (NL); Burin Peninsula Health Care Centre, Burin, NL; Carbonear General Hospital, Carbonear, NL; Dr. G.B. Cross Memorial Hospital, Clarenville, NL; Janeway Children's Hospital and Rehabilitation Centre, St. John's, NL; St. Clare's Mercy Hospital, St. John's, NL; Sir Thomas Roddick Hospital, Stephenville, NL; McMaster Children's Hospital, Hamilton, ON; St. Joseph's Healthcare, Hamilton, ON; Jurvinski Hospital and Cancer Center, Hamilton, ON; General Site, Hamilton, ON; Civic Campus, Ottawa, ON; General Campus, Ottawa, ON; University of Ottawa Heart Institute, Ottawa, ON; Hôpital Maisonneuve-Rosemont, Montréal, QC; Victoria General Hospital, Victoria, BC; Royal Jubilee, Victoria, BC; Nanaimo Regional General Hospital, Nanaimo, BC; Children's Hospital of Eastern Ontario (CHEO), Ottawa, ON; BC Women's Hospital, Vancouver, BC; Hôtel-Dieu de Québec, QC; Centre hospitalier de l'Université de Montréal, Montréal, QC; Montréal General Hospital, Montréal, QC; Centre Hospitalier Universitaire Sainte-Justine, Montréal, QC; Royal Victoria Hospital, Montréal, QC; Montréal Neurological Institute, Montréal, QC; North York General Hospital, Toronto, ON; Kelowna General Hospital, Kelowna, BC; Queen Elizabeth Hospital, Charlottetown, Prince Edward Island (PE); Prince County Hospital, Summerside, PE; Western Memorial Regional Hospital, Corner Brook, NL; Regina General Hospital, Regina, SK; Pasqua Hospital, Regina, SK; Sudbury Regional Hospital, Sudbury, ON; University Hospital of Northern BC, Prince George, BC; Qikiqtani General Hospital, Nunavut.

Thank you to the staff at Public Health Agency of Canada in the Centre for Communicable Diseases and Infection Control, Ottawa, ON (L Pelude, R Mitchell, KB Choi, A Silva, J Cayen, JB Bartoszko, D Lee, W Rudnick and C McClellan) and the National Microbiology Laboratory, Winnipeg, MB (G Golding, M Mulvey, J Campbell, T Du, M McCracken, L Mataseje, A Bharat, R Edirmanasinghe, R Hizon, S Ahmed, K Fakharuddin, D Spreitzer and D Boyd).

Funding

This work was supported by Public Health Agency of Canada.