Big city, small world: density, contact rates, and transmission of dengue across Pakistan.
Big city, small world: density, contact rates, and transmission of dengue across Pakistan.
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DOI：
10.1098/rsif.2015.0468
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发表时间：
2015-10-06
期刊：
影响因子：
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通讯作者：
Reiner RC Jr
中科院分区：
文献类型：
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作者：
Kraemer MU;Perkins TA;Cummings DA;Zakar R;Hay SI;Smith DL;Reiner RC Jr
对种群的宏观描述通常假定个体之间的接触是混合的；即每个个体与任何其他个体接触的机会都是平等的。然而，放松这一假设可能是具有挑战性的，因为很难获得关于遭遇的非随机性质的详细知识。在这里，我们将登革热病毒传播的数学模型与来自巴基斯坦的空间时间序列数据进行了拟合，并比较了在城乡梯度上分解数据时“混合参数”的最大似然估计。我们表明，这种梯度上的动力学不仅取决于不同的传输强度，而且还取决于由于混合的不同而产生的不同的非线性强度。通过合并两个细微尺度的、依赖于密度的协变量层来考虑流动性的差异，消除了混合的差异，但导致拉合尔大城市地区的估计传播潜力翻了一番。我们进一步表明，忽视混合中的空间差异可能会导致对通过疫苗或其他干预措施控制病原体所需的努力水平的严重低估。我们通过估计登革热传播强度与其他假定的环境驱动因素之间的关系来补充这一分析。
Macroscopic descriptions of populations commonly assume that encounters between individuals are well mixed; i.e. each individual has an equal chance of coming into contact with any other individual. Relaxing this assumption can be challenging though, due to the difficulty of acquiring detailed knowledge about the non-random nature of encounters. Here, we fitted a mathematical model of dengue virus transmission to spatial time-series data from Pakistan and compared maximum-likelihood estimates of ‘mixing parameters’ when disaggregating data across an urban–rural gradient. We show that dynamics across this gradient are subject not only to differing transmission intensities but also to differing strengths of nonlinearity due to differences in mixing. Accounting for differences in mobility by incorporating two fine-scale, density-dependent covariate layers eliminates differences in mixing but results in a doubling of the estimated transmission potential of the large urban district of Lahore. We furthermore show that neglecting spatial variation in mixing can lead to substantial underestimates of the level of effort needed to control a pathogen with vaccines or other interventions. We complement this analysis with estimates of the relationships between dengue transmission intensity and other putative environmental drivers thereof.