Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, Pennsylvania, United States of America.
PLoS One. 2010 Feb 26;5(2):e9360. doi: 10.1371/journal.pone.0009360.
As Pandemic (H1N1) 2009 influenza spreads around the globe, it strikes school-age children more often than adults. Although there is some evidence of pre-existing immunity among older adults, this alone may not explain the significant gap in age-specific infection rates.
Based on a retrospective analysis of pandemic strains of influenza from the last century, we show that school-age children typically experience the highest attack rates in primarily naive populations, with the burden shifting to adults during the subsequent season. Using a parsimonious network-based mathematical model which incorporates the changing distribution of contacts in the susceptible population, we demonstrate that new pandemic strains of influenza are expected to shift the epidemiological landscape in exactly this way.
Our analysis provides a simple demographic explanation for the age bias observed for H1N1/09 attack rates, and suggests that this bias may shift in coming months. These results have significant implications for the allocation of public health resources for H1N1/09 and future influenza pandemics.
随着 2009 年甲型 H1N1 流感在全球范围内的传播，它比成年人更常袭击学龄儿童。尽管老年人中存在一定程度的预先存在的免疫，但仅凭这一点可能无法解释特定年龄组感染率的显著差异。
基于对上世纪大流行流感株的回顾性分析，我们表明，在主要为易感人群的情况下，学龄儿童通常经历最高的攻击率，而在随后的季节中，负担则转移到成年人身上。使用一种基于网络的简约数学模型，该模型结合了易感人群中接触者分布的变化，我们证明了新的大流行流感株预计会以这种方式改变流行病学格局。
我们的分析为 H1N1/09 攻击率所观察到的年龄偏见提供了一个简单的人口统计学解释，并表明这种偏见可能在未来几个月发生变化。这些结果对 H1N1/09 和未来流感大流行的公共卫生资源分配具有重要意义。
