Human mobility and the spatial transmission of influenza in the United States.
Human mobility and the spatial transmission of influenza in the United States.
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DOI：
10.1371/journal.pcbi.1005382
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发表时间：
2017-02
影响因子：
4.3
通讯作者：
Viboud C
中科院分区：
文献类型：
--
作者：
Charu V;Zeger S;Gog J;Bjørnstad ON;Kissler S;Simonsen L;Grenfell BT;Viboud C
季节性流感流行为研究部分免疫人群中病原体的入侵和再入侵波提供了独特的机会。然而，由于缺乏详细的疾病数据，详细的传播模式仍然难以捉摸。在这里，我们对大量城市级医疗索赔数据和人员流动代理进行建模，以探索 2002 年至 2010 年期间美国流感传播的驱动因素。尽管传播速度和途径因季节而异，但八种流行病中有七种可能起源于美国南部。每次流行病都与 1-5 次早期远距离传播事件相关，其中一半引发了进一步传播。重力模型估计表明，随着感染城市和易感城市之间距离的增加，流感传播急剧衰减，这与以工作通勤而非空中交通为主的传播相一致。与抗原新颖性相关的两个早发季节具有特别局部化的传播模式，这表明新毒株可能以比之前预期更局部化的方式传播。决定季节性流感空间传播的基本机制仍然知之甚少，部分原因是缺乏空间分辨的疾病数据来量化传播模式。在本文中，我们通过分析美国约 300 个地点八个季节流感类疾病的细粒度保险索赔数据来解决这个问题。通过统计方法，我们发现八种流行病中有七种可能起源于美国南部，流感空间传播以城市之间的局部交通为主，新型流感病毒传播的季节具有特别放射状、局部化的空间结构。这些发现与流行的流感空间传播理论形成鲜明对比，该理论认为低湿度环境有利于传播，并且传播主要由人口稠密的枢纽之间的空中交通主导。
Seasonal influenza epidemics offer unique opportunities to study the invasion and re-invasion waves of a pathogen in a partially immune population. Detailed patterns of spread remain elusive, however, due to lack of granular disease data. Here we model high-volume city-level medical claims data and human mobility proxies to explore the drivers of influenza spread in the US during 2002–2010. Although the speed and pathways of spread varied across seasons, seven of eight epidemics likely originated in the Southern US. Each epidemic was associated with 1–5 early long-range transmission events, half of which sparked onward transmission. Gravity model estimates indicate a sharp decay in influenza transmission with the distance between infectious and susceptible cities, consistent with spread dominated by work commutes rather than air traffic. Two early-onset seasons associated with antigenic novelty had particularly localized modes of spread, suggesting that novel strains may spread in a more localized fashion than previously anticipated. The underlying mechanisms dictating the spatial spread of seasonal influenza remain poorly understood, in part because of the lack of spatially resolved disease data to quantify patterns of spread. In this paper, we address this issue by analyzing fine-grain insurance claims data on influenza-like-illnesses over eight seasons in ~300 locations throughout the United States. Using statistical methods, we found that seven of eight epidemics likely originated in the Southern US, that influenza spatial transmission is dominated by local traffic between cities, and that seasons marked by novel influenza virus circulation had a particularly radial, localized spatial structure. These findings are in stark contrast to prevailing theories of influenza spatial transmission that suggest that transmission is favored in low humidity environments and that spread is a dominated by air traffic between populous hubs.