Preventable H5N1 avian influenza epidemics in the British poultry industry network exhibit characteristic scales
Preventable H5N1 avian influenza epidemics in the British poultry industry network exhibit characteristic scales
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DOI：
10.1098/rsif.2009.0304
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发表时间：
2010-04-06
影响因子：
3.9
通讯作者：
Christley, R. M.
中科院分区：
文献类型：
--
作者：
Jonkers, A. R. T.;Sharkey, K. J.;Christley, R. M.
流行病经常在冗余连接的接触网络上模拟，这些网络在站点之间的链接比连接所有站点所需的最低限度要多得多。因此，模拟的病原体可以传播许多替代路线，使有效的遏制策略复杂化。此外，这些网络已被发现表现出“无标度”的属性和渗流，这表明对损害的弹性。然而，现实的H5 N1禽流感传播概率和遏制策略，在这里模拟英国家禽业网络，表明感染动态可以另外表示特征尺度。这些系统偏好的尺度构成了观察到的幂律分布内的小区域，其表现出比幂律本身更小的斜率，表明相对可能性略有增加。这些特征尺度在这里是由所谓的热点站点的网络普及的内联网产生的，这些热点站点在渗流阈值以下传播大的流行病。然而，这一内联网是极其脆弱的;英国家禽业网络中仅有3-6%（取决于纳入的生物安全措施）的有针对性的接种完全防止了大规模和中等规模的H5 N1爆发，这比以前提倡的影响连接最紧密的“枢纽”站点的战略提供了一个数量级的改进。换句话说，热点和枢纽是独立的功能实体，不一定重合，热点可以成为更有效的接种靶标。考虑到网络（流行病、互联网、电网、蛋白质相互作用）的普遍性和相关性，认识到其他地方的这种传播机制将表明对这种外科干预的类似不成比例的敏感性。
Epidemics are frequently simulated on redundantly wired contact networks, which have many more links between sites than are minimally required to connect all. Consequently, the modelled pathogen can travel numerous alternative routes, complicating effective containment strategies. These networks have moreover been found to exhibit 'scale-free' properties and percolation, suggesting resilience to damage. However, realistic H5N1 avian influenza transmission probabilities and containment strategies, here modelled on the British poultry industry network, show that infection dynamics can additionally express characteristic scales. These system-preferred scales constitute small areas within an observed power law distribution that exhibit a lesser slope than the power law itself, indicating a slightly increased relative likelihood. These characteristic scales are here produced by a network-pervading intranet of so-called hotspot sites that propagate large epidemics below the percolation threshold. This intranet is, however, extremely vulnerable; targeted inoculation of a mere 3-6% (depending on incorporated biosecurity measures) of the British poultry industry network prevents large and moderate H5N1 outbreaks completely, offering an order of magnitude improvement over previously advocated strategies affecting the most highly connected 'hub' sites. In other words, hotspots and hubs are separate functional entities that do not necessarily coincide, and hotspots can make more effective inoculation targets. Given the ubiquity and relevance of networks (epidemics, Internet, power grids, protein interaction), recognition of this spreading regime elsewhere would suggest a similar disproportionate sensitivity to such surgical interventions.