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Sentinel surveillance for influenza requiring hospital admission in Canadian adults

Status: Currently recruiting

Why are we doing this?

As members of the PCIRN Serious Outcomes Surveillance Network (SOS), a research network comprised of 40 hospitals in New Brunswick, Nova Scotia, Quebec, Ontario, Manitoba and British Columbia, we are participating in a study to monitor the effectiveness of seasonal influenza vaccines by tracking the incidence and severity of disease in adults hospitalized with influenza. The SOS Network also assesses the health and economic burden of influenza in Canadian adults, in order to best understand how vaccines can be used to prevent influenza disease in adults, and to understand risk factors for more severe disease. The research conducted by the Network can also be used to assess the effectiveness of new vaccines as they become available.

Study Objectives

  • To determine the effectiveness of trivalent influenza vaccination (TIV in general, and GSK TIV in particular) in preventing influenza-associated hospitalization in adults 65 years and older
  • To determine the effectiveness of influenza vaccination in preventing influenza-associated death in adults 65 years and older
  • To determine the effectiveness of influenza vaccination in preventing influenza-associated hospitalization and death in adults < 65 years old
  • To characterize the burden of disease, clinical outcomes, and resource utilization associated with influenza A and influenza B lineages
  • To examine clinical and immunologic factors impacting on severity of disease and influenza vaccine effectiveness in adults

Who is being asked to participate?

Any patients 16 years of age or older who are admitted to either of four Toronto hospitals participating in this study (Mount Sinai Hospital, North York General Hospital, William Osler Health System, Bramptom Civic Site and Toronto East General Hospital) with either of the following diagnosis or symptoms and had a nasal-phayngeal (NP) swabs, (a swab taken from far back in your nose), to test for influenza:

  • Community-acquired pneumonia (CAP)
  • Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) or asthma
  • Unexplained sepsis
  • Any  respiratory infection or diagnosis
  • Any respiratory or influenza-like symptom (eg shortness of breath, cough, sore throat, muscle or joint pain, or fever)
  • Any cardiac diagnosis (eg myocardial infarction (Heart attack), unstable angina, arrhythmias (irregular heat rhythm), myocarditis (inflamed heart muscle), or congestive heart failure) with temperature 37.5°C or higher
  • Stroke with temperature 37.5°C or higher

Based on the result of your influenza test, you will be asked to participate in the study as either a ‘case’ (positive influenza test) or a ‘control’ (negative influenza test).

You CANNOT participate if :

  • You are less than 16 years old
  • The reason for your admission to hospital was clearly unrelated to the presence of influenza (for example, patients admitted due to trauma, elective surgery, or patients who have an alternative diagnosis that is clearly not cardiac, respiratory, or neurologic, e.g. cellulitis, intra-abdominal process, or gastrointestinal bleeding)
  • You have a negative test for influenza (controls) but your immunization status cannot be determined (by verbal self report or another source eg. Family doctor or vaccination clinic) 

If I agree to participate, what will I need to do?

If you agree to participate you will be consenting to:

  • being interviewed for approximately 10-15 minutes about vaccination and possible risk factors for infection
  • being called by the study nurse about 1 month after discharge from the hospital to see how you are recovering since your illness
  • the release of information about you medical history from the hospital
  • the release of information about previous vaccinations and antibiotics from your family doctor and/or vaccination clinic
  • having any left over specimen from your nose swab sent to the study laboratory for possible future testing.

How long will the study last?

This study has been running since 2009 at Mount Sinai and since 2011 at North York General, Toronto East General and William Osler sites and is expected to be completed by May 2014.  We are currently enrolling for the 2012-2013 influenza season.

Are there any risks to participating in this study?

There are no risks for you in taking part in this study. You are not being given any medication and no change in your treatment will result from your participation. You may find the interviews or questions upsetting or distressing or you may not like all of the questions that you are asked. You may refuse to answer questions or stop the interview at any time if you are uncomfortable. We take every precaution to protect your personal information. Any information and left-over test sample you provide to the study is confidential and is identified only by a study code number. No one will be able to identify the study information or sample as belonging to you.

Who can I contact if I am interested in the study?   


  • Dr. Allison McGeer, Mount Sinai Hospital
  • Dr. David Richardson, William Osler Health System
  • Dr. Jeff Powis, Toronto East General Hospital
  • Dr. Kevin Katz, North York General Hospital
  • Dr. Shelly McNeil, Principal Investigator, Canadian Center for Vaccinology, Halifax


  • Dalhousie University


  • Public Health Agency of Canada (PHAC)
  • Canadian Institutes of Health Research (CIHR)
  • GlaxoSmithKline


This trial has been registered with (NCT01517191) and has been approved by the Research Ethics Boards at all participating hospitals.

Participating SOS Network Sites

Queen Elizabeth II Health Sciences Center, the IWK Health Centre and Dartmouth General Hospital in Halifax, NS, Mount Sinai Hospital, North York General Hospital,  and Toronto East General Hospital in Toronto, ON, William Osler Health System, Brampton Civic site  in Bramptom, ON, Hamilton Health Sciences Centre and St. Joseph’s Hospital in Hamilton, ON, The Ottawa Hospital (Civic Campus and General Campus) in Ottawa, ON, Foothills Medical Centre in Calgary, AB, Centre Hospitalier Universitaire de Quebec ( CHUQ-CHUL) Laval, Montreal General Hospital and Royal Victoria Hospital, Montreal, QuebecVancouver General Hospital, Vancouver BC, and Centre Hospitalier Universitaire de Sherbrooke, Hopital Fleurmont  in Sherbrooke, Quebec, St Boniface General Hospital, Winnipeg, Manitoba and the Toronto Invasive Bacterial Diseases Network, Toronto, Ontario. Additional adult acute care facilities will be recruited as feasible to provide more representative geographic distribution of sentinel sites within the Network and to provide more robust, region-specific data.

The SOS Network Coordinating Centre is located at the Canadian Center for Vaccinology in Halifax, NS.