Competing epidemics on complex networks
Competing epidemics on complex networks
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DOI：
10.1103/physreve.84.036106
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发表时间：
2011-09-09
影响因子：
2.4
通讯作者：
Newman, M. E. J.
中科院分区：
文献类型：
--
作者：
Karrer, Brian;Newman, M. E. J.
人类疾病通过个人之间的接触网络传播，最近的大量研究都集中在传播过程的动态上。在这里，我们研究了两种相互竞争的疾病同时在同一网络上传播的模型，其中感染了这两种疾病中的任何一种，个人随后都会对这两种疾病产生免疫力。使用解析和数值方法相结合的方法，我们得到了系统的相图，并估计了预期的最终感染每种疾病的人数。该系统显示出一种疾病的主导性和另一种主导性之间的不寻常的动态转变，这是它们相对增长率的函数。接近这一转变的最终结果显示，在增长的早期阶段，对随机波动的依赖性很强，这种依赖性随着网络规模的增加而减少，但这种依赖性足够慢，以至于在拥有数百万或数十亿人的系统中仍然很容易看到。在相图的大多数区域，我们发现一种疾病最终占主导地位，而另一种疾病只到达网络的一小部分，但系统也显示出显著的共存制度，其中两种疾病都达到了流行病的比例，并感染了网络的广泛部分。
Human diseases spread over networks of contacts between individuals and a substantial body of recent research has focused on the dynamics of the spreading process. Here we examine a model of two competing diseases spreading over the same network at the same time, where infection with either disease gives an individual subsequent immunity to both. Using a combination of analytic and numerical methods, we derive the phase diagram of the system and estimates of the expected final numbers of individuals infected with each disease. The system shows an unusual dynamical transition between dominance of one disease and dominance of the other as a function of their relative rates of growth. Close to this transition the final outcomes show strong dependence on stochastic fluctuations in the early stages of growth, dependence that decreases with increasing network size, but does so sufficiently slowly as still to be easily visible in systems with millions or billions of individuals. In most regions of the phase diagram we find that one disease eventually dominates while the other reaches only a vanishing fraction of the network, but the system also displays a significant coexistence regime in which both diseases reach epidemic proportions and infect an extensive fraction of the network.