Division of Infectious Diseases, Department of Paediatrics, Program in Genetics & Genome Biology, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
Pediatrics. 2012 Sep;130(3):397-406. doi: 10.1542/peds.2011-3216. Epub 2012 Aug 29.
The extent to which pandemic H1N1 influenza (pH1N1) differed from seasonal influenza remains uncertain.
By using active surveillance data collected by the Immunization Monitoring Program, Active at 12 Canadian pediatric hospitals, we compared characteristics of hospitalized children with pH1N1 with those with seasonal influenza A. We compared demographics, underlying health status, ICU admission, and mortality during both pandemic waves versus the 2004/2005 through the 2008/2009 seasons; influenza-related complications and hospitalization duration during pH1N1 wave 1 versus the 2004/2005 through the 2008/2009 seasons; and presenting signs and symptoms during both pH1N1 waves versus the 2006/2007 through the 2008/2009 seasons.
We identified 1265 pH1N1 cases (351 in wave 1, 914 in wave 2) and 1319 seasonal influenza A cases (816 from 2006/2007 through 2008/2009). Median ages were 4.8 (pH1N1) and 1.7 years (seasonal influenza A); P < .0001. Preexisting asthma was overrepresented in pH1N1 relative to seasonal influenza A (13.8% vs 5.5%; adjusted P < .0001). Symptoms more often associated with pH1N1 wave 1 versus seasonal influenza A were cough, headache, and gastrointestinal symptoms (adjusted P < .01 for each symptom). pH1N1 wave 1 cases were more likely to have radiologically confirmed pneumonia (adjusted odds ratio = 2.1; 95% confidence interval = 1.1-3.8) and longer median length of hospital stay (4 vs 3 days; adjusted P = .003) than seasonal influenza A. Proportions of children requiring intensive care and deaths in both pH1N1 waves (14.6% and 0.6%, respectively) were not significantly different from the seasonal influenza A group (12.7% and 0.5%, respectively).
pH1N1 in children differed from seasonal influenza A in risk factors, clinical presentation, and length of hospital stay, but not ICU admission or mortality.
大流行 H1N1 流感（pH1N1）与季节性流感的不同之处仍不确定。
通过使用加拿大 12 家儿童医院免疫监测计划主动监测收集的数据，我们比较了 pH1N1 住院患儿与季节性流感 A 患儿的特征。我们比较了大流行期间（第 1 波和第 2 波）与 2004/2005 年至 2008/2009 年期间的人口统计学特征、基础健康状况、入住重症监护病房（ICU）和死亡率；第 1 波 pH1N1 与 2004/2005 年至 2008/2009 年期间的流感相关并发症和住院时间；以及两个 pH1N1 波与 2006/2007 年至 2008/2009 年期间的临床表现和症状。
我们确定了 1265 例 pH1N1 病例（第 1 波 351 例，第 2 波 914 例）和 1319 例季节性流感 A 病例（2006/2007 年至 2008/2009 年 816 例）。中位年龄分别为 4.8 岁（pH1N1）和 1.7 岁（季节性流感 A）；P<0.0001。与季节性流感 A 相比，pH1N1 中既往哮喘的比例更高（13.8%比 5.5%；调整后 P<0.0001）。与季节性流感 A 相比，pH1N1 第 1 波更常出现咳嗽、头痛和胃肠道症状（每个症状的调整后 P<0.01）。pH1N1 第 1 波的病例更有可能经影像学证实患有肺炎（调整后的优势比=2.1；95%置信区间=1.1-3.8），且中位住院时间更长（4 天比 3 天；调整后 P=0.003）。两个 pH1N1 波的儿童需要入住重症监护病房的比例（分别为 14.6%和 0.6%）与季节性流感 A 组（分别为 12.7%和 0.5%）无显著差异。
儿童中的 pH1N1 与季节性流感 A 在危险因素、临床表现和住院时间方面存在差异，但在入住重症监护病房或死亡率方面没有差异。
