892 Laboratory Confirmed Seasonal Influenza in Adults in a Network of Canadian Hospitals 2006-2009

Sunday, March 21, 2010
Grand Hall (Hyatt Regency Atlanta)
Krista D. Wilkinson, BSc , Public Health Agency of Canada, Ottawa, ON, Canada
Geoffrey Taylor, MD , University of Alberta Hospital, Edmonton, AB, Canada
Denise Gravel, MSc , Public Health Agency of Canada, Ottawa, ON, Canada
Charles Frenette, MD , McGill University Health Centre, Montreal, QC, Canada
Allison McGeer, MD , Mount Sinai Hospital, Toronto, ON, Canada
Dorothy Moore, MD, PhD , Montreal Children's Hospital, Montreal, QC, CANADA
Kathryn Suh, MD, MSc , The Ottawa Hospital, Ottawa, ON, Canada
Joseph Vayalumkal, MD , Alberta Children's Hospital, Calgary, AB, CANADA
Alice Wong, MD , Royal University Hospital, Saskatoon, SK, Canada
Agnes Tong , Mount Sinai Hospital, Toronto, ON, Canada
Barbara Amihod, RN , The Jewish General Hospital, Montrial, QC, Canada
Background: The Canadian Nosocomial Infection Surveillance Program (a collaboration between the Public Health Agency of Canada and the Association for Medical Microbiology and Infectious Diseases – Canada) is a sentinel network of 56 mainly large teaching hospitals in Canadian cities. CNISP has conducted surveillance for seasonal influenza (flu) in hospitalized adults since 2006

Objective: To describe the experience with seasonal flu in hospitalized adults for the 2008-09 year compared with the 2 previous seasons.

Methods: A case was defined as an inpatient in one of the participating hospitals with laboratory confirmed flu by any test method. Data were prospectively collected by the hospital infection control professional. Deaths before 30 days after diagnosis were reviewed. Cases occurring from 1/11/08-25/04/09 (before first cases of pandemic H1N1 occurred in Canada) were compared to cases from the ’06-’07 and ’07-’08 seasons

Results: In the 2008-09 season there were 11 participating hospitals. From 1/11/08 through 25/04/09 there were 100 identified flu cases (26% flu B 74% flu A), 54% male, mean age 57 years. The admission rate was 1.15/1000 admissions (range 0.27-2.80), significantly (p<0.001) lower than the 2007-2008 season (3.54/1000). 86% of ’08-’09 cases were vaccine eligible but only 56% of these where vaccine status was available, had been vaccinated. 82% were treated with antibacterial therapy and 42% with antiviral therapy. While 30 day mortality was unchanged compared to 2007-08 (8%) the ICU admission rate (30%) was higher than in either ’06-’07 or ’07-’08 (9%) (p<0.001). Mortality at 30 days was 11%; influenza was considered to be primary or contributing cause of death in 8 patients - 8% compared to 2.8% in ’07-’08 (p=0.009) .

Conclusions: Seasonal influenza in Canada in ‘08-‘09 resulted in a lower hospitalization rate than in ‘07-‘08 but a higher ICU admission rate and higher attributable mortality. There continues to be missed opportunities for vaccine prevention and antiviral therapy in this population