Skip to main content Accessibility help

Healthcare-Associated Influenza in Canadian Hospitals from 2006 to 2012

  • Geoffrey Taylor (a1), Robyn Mitchell (a2), Allison McGeer (a3), Charles Frenette (a4), Kathryn N. Suh (a5), Alice Wong (a6), Kevin Katz (a7), Krista Wilkinson (a2), Barbara Amihod (a8), Denise Gravel (a2) and Canadian Nosocomial Infection Surveillance Program...



To determine trends, patient characteristics, and outcome of patients with healthcare-associated influenza in Canadian hospitals.


Prospective surveillance of laboratory-confirmed influenza among hospitalized adults was conducted from 2006 to 2012. Adults with positive test results at or after admission to the hospital were assessed. Influenza was considered to be healthcare associated if symptom onset was equal to or more than 96 hours after admission to a facility or if a patient was readmitted less than 96 hours after discharge or admitted less than 96 hours after transfer from another facility. Baseline characteristics of influenza patients were collected. Patients were reassessed at 30 days to determine the outcome.


Acute care hospitals participating in the Canadian Nosocomial Infection Surveillance Program.


A total of 570 (17.3%) of 3,299 influenza cases were healthcare associated; 345 (60.5%) were acquired in a long-term care facility (LTCF), and 225 (39.5%) were acquired in an acute care facility (ACF). There was year-to-year variability in the rate and proportion of cases that were healthcare associated and variability in the proportion that were acquired in a LTCF versus an ACF. Patients with LTCF-associated cases were older, had a higher proportion of chronic heart disease, and were less likely to be immunocompromised compared with patients with ACF-associated cases; there was no significant difference in 30-day all-cause and influenza-specific mortality.


Healthcare-associated influenza is a major component of the burden of disease from influenza in hospitals, but the proportion of cases that are healthcare associated varies markedly from year to year, as does the proportion of healthcare-associated infections that are acquired in an ACF versus an LTCF.


Corresponding author

2D3 05 WMC, University of Alberta, Edmonton, Alberta T6G 2B7, Canada (


Hide All

Members of the Canadian Nosocomial Infection Surveillance Program are listed at the end of the text.



Hide All
1. Saigado, CD, Farr, BM, Hall, KK, Hayden, FG. Influenza in the acute hospital setting. Lancet Infect Dis 2002;2:145155.
2. Bradley, SF. Prevention of influenza in long-term-care facilities. Long-Term Care Committee of the Society for Healthcare Epidemiology of America. Infect Control Hosp Epidemiol 1999; 20(9):629637.
3. Coles, FB, Balzano, GJ, Morse, DL. An outbreak of influenza A (H3N2) in a well immunized nursing home population. J Am Geriatr Soc 1992;40(6):589592.
4. Voirin, N, Barret, B, Metzger, MH, Vanhems, P. Hospital-acquired influenza: a synthesis using the Outbreak Reports and Intervention Studies of Nosocomial Infection (ORION) statement. J Hosp Infect 2009;71(1):114.
5. Morens, DM, Rash, VM. Lessons from a nursing home outbreak of influenza A. Infect Control Hosp Epidemiol 1995;16(5):275280.
6. Cohen, NJ, Morita, JY, Plate, DK, et al. Control of an outbreak due to an adamantine-resistant strain of influenza A (H3N2) in a chronic care facility. Infection 2008;36(5):458462.
7. Alexander, DC, Winter, AL, Eshaghi, A, et al. Transmission of influenza A pandemic (H1N1) 2009 virus in a long-term care facility in Ontario, Canada. Infect Control Hosp Epidemiol 2010; 31(12):13001302.
8. Enstone, JE, Myles, PR, Openshaw, PJM, et al. Nosocomial pandemic (H1N1) 2009, United Kingdom, 2009-2010. Emerg Infect Dis 2011;17:592598.
9. Khandaker, G, Rashid, H, Zurynski, Y, et al Nosocomial vs community-acquired pandemic influenza A (H1N1) 2009: a nested case-control study. J Hosp Infect 2012;82(2):94100.
10. Veenith, T, Sanfilippo, F, Ercole, A, et al Nosocomial H1N1 infection during 2010-2011 pandemic: a retrospective cohort study from a tertiary referral hospital. J Hosp Infect 2012;81(3): 202205.
11. Macesic, N, Kotsimbos, TC, Kelly, P, Cheng, AC. Hospital-acquired influenza in an Australian sentinel surveillance system. MJA 2013;198:370372.
12. Vanhems, P, Voirin, N, Roche, S, et al. Risk of influenza-like illness in an acute health care setting during community influenza epidemics in 2004-2005, 2005-2006, and 2006-2007. Arch Intern Med 2011;171(2):151157.
13. Wilkinson, K, Mitchell, R, Taylor, G, et al. Laboratory-confirmed pandemic H1N1 influenza in hospitalized adults: findings from the Canadian Nosocomial Infections Surveillance Program, 2009-2010. Infect Control Hosp Epidemiol 2012;33(10):10431046.
14. Harper, SA, Bradley, JS, Englund, JA, et al. Seasonal influenza in adults and children-diagnosis, treatment, chemoprophylaxis and institutional outbreak management: clinical practice guidelines of the Infectious Diseases Society of America. Clin Infect Dis 2009;48:10031032.
15. Skowronski, DM, Hottes, TS, McElhaney, JE, et al. Immuno-epidemiologic correlates of pandemie H1N1 surveillance observations: higher antibody and lower cell-mediated immune responses with advanced age. J Infect Dis 2011;203:158167.
16. Hall, WN, Goodman, RA, Noble, GR, Kendal, AP, Steece, RS. An outbreak of influenza B in an elderly population. J Infect Dis 1981;144(4):297302.
17. Aoki, F, Hayden, F. The beneficial effects of neuraminidase in hibitor drug therapy on severe patient outcomes during the 2009-2010 influenza A virus subtype H1N1 pandemic. J Infect Dis 2013;207:547549.
18. Bryce, E, Embree, J, Evans, G, et al. AMMI Canada position paper: mandatory influenza immunization of health care workers. Can J Infect Dis Med Microbiol 2012;23:e93e95.
19. Gardam, M, Lemieux, C. Mandatory influenza vaccination? first we need a better vaccine. CMAJ 2013;185:639640.


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed