大流行（H1N1）2009 年第一波和第二波期间的住院和严重后果发生率。
Incidence of hospital admissions and severe outcomes during the first and second waves of pandemic (H1N1) 2009.
机构信息
Centre for Immunization and Respiratory Infectious Diseases, Public Health Agency of Canada, Ottawa, Ont., Canada.
出版信息
CMAJ. 2010 Dec 14;182(18):1981-7. doi: 10.1503/cmaj.100746. Epub 2010 Nov 8.
BACKGROUND
Canada experienced two distinct waves of pandemic (H1N1) influenza during the 2009 pandemic, one in the spring and the second in early fall 2009. We compared the incidence of hospital admissions and severe outcomes (admission to intensive care unit [ICU] and death) during the two waves.
METHODS
We reviewed data on all laboratory-confirmed cases of pandemic (H1N1) influenza that resulted in hospital admission, ICU admission or death reported to the Public Health Agency of Canada by all provinces and territories from Apr. 18, 2009, to Apr. 3, 2010.
RESULTS
A total of 8678 hospital admissions (including 1473 ICU admissions) and 428 deaths related to pandemic (H1N1) influenza were reported during the pandemic and post-peak period. There were 4.8 times more hospital admissions, 4.0 times more ICU admissions and 4.6 times more deaths in the second pandemic wave than in the first wave. ICU admissions and deaths as a proportion of hospital admissions declined in the second wave; there was a 16% proportional decline in ICU admissions and a 6% proportional decline in deaths compared with the first wave. Compared with patients admitted to hospital in the first wave, those admitted in the second wave were older (median age 30 v. 23 years) and more had underlying conditions (59.7% v. 47.5%). Pregnant women and Aboriginal people accounted for proportionally fewer patients who were admitted to hospital or who died in the second wave than in the first.
INTERPRETATION
The epidemiologic features of the first and second waves of the 2009 pandemic differed. The second wave was substantially larger and, although the patients admitted to hospital were older and more of them had underlying conditions, a smaller proportion had a severe outcome.
背景
加拿大在 2009 年大流行期间经历了两次截然不同的流感大流行（H1N1）浪潮，一次是在春季，另一次是在 2009 年早秋。我们比较了两次浪潮期间住院和严重后果（入住重症监护病房[ICU]和死亡）的发生率。
方法
我们回顾了 2009 年 4 月 18 日至 2010 年 4 月 3 日期间，所有省份和地区向加拿大公共卫生局报告的所有实验室确诊的大流行（H1N1）流感导致住院、入住 ICU 或死亡的病例数据。
结果
大流行和高峰期过后，共报告了 8678 例与大流行（H1N1）流感相关的住院治疗（包括 1473 例 ICU 入院）和 428 例死亡。第二波疫情的住院人数是第一波的 4.8 倍，ICU 入院人数是第一波的 4.0 倍，死亡人数是第一波的 4.6 倍。第二波 ICU 入院和死亡人数占住院人数的比例下降；与第一波相比，ICU 入院人数下降了 16%，死亡人数下降了 6%。与第一波入院的患者相比，第二波入院的患者年龄更大（中位数年龄 30 岁 vs. 23 岁），且更多合并基础疾病（59.7% vs. 47.5%）。孕妇和原住民在第二波中住院或死亡的比例较第一波有所下降。
结论
2009 年大流行的第一波和第二波的流行病学特征不同。第二波规模大得多，尽管入院患者年龄较大，合并基础疾病的比例较高，但严重后果的比例较小。
Zotero 插件