Centre for Immunization and Respiratory Infectious Diseases, Infectious Disease and Emergency Preparedness Branch, Public Health Agency of Canada, Ottawa, Ontario.
CMAJ. 2010 Mar 9;182(4):349-55. doi: 10.1503/cmaj.091823. Epub 2010 Feb 16.
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.
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.
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.
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.
我们描述了加拿大所有因大流行性（H1N1）流感住院的患者的疾病特征和结局，包括入住重症监护病房（ICU）和死亡的危险因素。
我们从 2009 年 4 月 26 日至 9 月 26 日期间，从加拿大公共卫生局报告的经实验室确诊的大流行性（H1N1）流感住院患者中获得了所有患者的数据。我们比较了患有非严重疾病的住院患者和患有严重疾病（如入住 ICU 或死亡）的住院患者。
在研究期间，共有 1479 名患者因确诊的大流行性（H1N1）流感住院。其中，1171 例（79.2％）无严重后果，236 例（16.0％）入住 ICU 并存活，72 例（4.9％）死亡。所有患者的中位年龄为 23 岁，无严重后果者为 18 岁，入住 ICU 并存活者为 34 岁，死亡者为 51 岁。有基础疾病和 20 岁及以上的患者发生严重后果的风险较高。症状出现至住院的中位时间每延迟一天，死亡风险增加 5.5％。在五个月的时间里，严重后果的风险相对保持不变。
在加拿大大流行的前五个月，经实验室确诊的大流行性（H1N1）流感住院的人群发病率较低。严重后果的风险与存在一种或多种基础疾病、20 岁及以上的年龄以及住院延迟有关。
