BACKGROUND: We describe the disease characteristics and outcomes, including risk factors for admission to intensive care unit (ICU) and death, of all patients in Canada admitted to hospital with pandemic (H1N1) influenza during the first five months of the pandemic. METHODS: We obtained data for all patients admitted to hospital with laboratory-confirmed pandemic (H1N1) influenza reported to the Public Health Agency of Canada from Apr. 26 to Sept. 26, 2009. We compared inpatients who had nonsevere disease with those who had severe disease, as indicated by admission to ICU or death. RESULTS: A total of 1479 patients were admitted to hospital with confirmed pandemic (H1N1) influenza during the study period. Of these, 1171 (79.2%) did not have a severe outcome, 236 (16.0%) were admitted to ICU and survived, and 72 (4.9%) died. The median age was 23 years for all of the patients, 18 years for those with a nonsevere outcome, 34 years for those admitted to ICU who survived and 51 years for those who died. The risk of a severe outcome was elevated among those who had an underlying medical condition and those 20 years of age and older. A delay of one day in the median time between the onset of symptoms and admission to hospital increased the risk of death by 5.5%. The risk of a severe outcome remained relatively constant over the five-month period. INTERPRETATION: The population-based incidence of admission to hospital with laboratory-confirmed pandemic (H1N1) influenza was low in the first five months of the pandemic in Canada. The risk of a severe outcome was associated with the presence of one or more underlying medical conditions, age of 20 years or more and a delay in hospital admission.
BACKGROUND: We describe the disease characteristics and outcomes, including risk factors for admission to intensive care unit (ICU) and death, of all patients in Canada admitted to hospital with pandemic (H1N1) influenza during the first five months of the pandemic. METHODS: We obtained data for all patients admitted to hospital with laboratory-confirmed pandemic (H1N1) influenza reported to the Public Health Agency of Canada from Apr. 26 to Sept. 26, 2009. We compared inpatients who had nonsevere disease with those who had severe disease, as indicated by admission to ICU or death. RESULTS: A total of 1479 patients were admitted to hospital with confirmed pandemic (H1N1) influenza during the study period. Of these, 1171 (79.2%) did not have a severe outcome, 236 (16.0%) were admitted to ICU and survived, and 72 (4.9%) died. The median age was 23 years for all of the patients, 18 years for those with a nonsevere outcome, 34 years for those admitted to ICU who survived and 51 years for those who died. The risk of a severe outcome was elevated among those who had an underlying medical condition and those 20 years of age and older. A delay of one day in the median time between the onset of symptoms and admission to hospital increased the risk of death by 5.5%. The risk of a severe outcome remained relatively constant over the five-month period. INTERPRETATION: The population-based incidence of admission to hospital with laboratory-confirmed pandemic (H1N1) influenza was low in the first five months of the pandemic in Canada. The risk of a severe outcome was associated with the presence of one or more underlying medical conditions, age of 20 years or more and a delay in hospital admission.
Authors: S Hackett; L Hill; J Patel; N Ratnaraja; A Ifeyinwa; M Farooqi; U Nusgen; P Debenham; D Gandhi; N Makwana; E Smit; S Welch Journal: Lancet Date: 2009-08-22 Impact factor: 79.321
Authors: M G Baker; N Wilson; Q S Huang; S Paine; L Lopez; D Bandaranayake; M Tobias; K Mason; G F Mackereth; M Jacobs; C Thornley; S Roberts; C McArthur Journal: Euro Surveill Date: 2009-08-27
Authors: Donald R Olson; Richard T Heffernan; Marc Paladini; Kevin Konty; Don Weiss; Farzad Mostashari Journal: PLoS Med Date: 2007-08 Impact factor: 11.069
Authors: Danuta M Skowronski; Travis S Hottes; Naveed Z Janjua; Dale Purych; Suzana Sabaiduc; Tracy Chan; Gaston De Serres; Jennifer Gardy; Janet E McElhaney; David M Patrick; Martin Petric Journal: CMAJ Date: 2010-10-18 Impact factor: 8.262
Authors: Beth A Halperin; Donna MacKinnon-Cameron; Shelly McNeil; Jennifer Kalil; Scott A Halperin Journal: Hum Vaccin Immunother Date: 2014 Impact factor: 3.452
Authors: Deborah L Thompson; Jessica Jungk; Emily Hancock; Chad Smelser; Michael Landen; Megin Nichols; David Selvage; Joan Baumbach; Mack Sewell Journal: Am J Public Health Date: 2011-07-21 Impact factor: 9.308
Authors: Jessica Y Wong; Heath Kelly; Chung-Mei M Cheung; Eunice Y Shiu; Peng Wu; Michael Y Ni; Dennis K M Ip; Benjamin J Cowling Journal: Am J Epidemiol Date: 2015-07-18 Impact factor: 4.897
Authors: Luiz C Mostaço-Guidolin; Sherry M J Towers; David L Buckeridge; Seyed M Moghadas Journal: Am J Public Health Date: 2012-12-13 Impact factor: 9.308
Authors: Maria E Lorenzo; Andrea Hodgson; Dionne P Robinson; Jenifer B Kaplan; Andrew Pekosz; Sabra L Klein Journal: Vaccine Date: 2011-10-06 Impact factor: 3.641