A dynamic power-law sexual network model of gonorrhoea outbreaks
A dynamic power-law sexual network model of gonorrhoea outbreaks
复制标题
淋病暴发的动态幂律性网络模型
DOI：
10.1101/322875
复制
发表时间：
2018
影响因子：
4.3
通讯作者：
X. Didelot
中科院分区：
文献类型：
--
作者：
L. Whittles;P. White;X. Didelot
人类的性接触网络本质上是动态的，随着时间的推移，伙伴关系不断形成和破裂。性行为也具有高度的异质性，因此在一段时间内，个人报告的性伴侣数量通常呈幂律分布。性伙伴关系的动态性和异质性都可能对性传播疾病的传播模式产生影响。为了表示性网络的这两个基本特性，我们开发了一个动态伙伴关系形成和解散的随机过程，这导致了伙伴数量随时间的幂律。可以设置模型参数，以根据幂律分布指数、没有关系的个体数量和关系的平均持续时间来产生现实条件。以男同性性行为中抗生素耐药性淋病的爆发为例研究，我们表明，与常用的静态网络或均匀混合模型相比，我们的现实动态网络表现出不同的特性。我们还考虑了一个近似于动态网络模型的更简单的分支过程。我们估计了代时间分布和后代分布的参数，这些参数可以用于例如基于基因组数据的爆发重建。最后，我们调查了一系列针对淋病的干预措施的影响，包括增加避孕套的使用、更频繁的筛查和免疫接种，得出结论认为，后者显示出减轻淋病负担的巨大希望，即使疫苗只是部分有效或只适用于随机的人口子集。
Human networks of sexual contacts are dynamic by nature, with partnerships forming and breaking continuously over time. Sexual behaviours are also highly heterogeneous, so that the number of partners reported by individuals over a given period of time is typically distributed as a power-law. Both the dynamism and heterogeneity of sexual partnerships are likely to have an effect in the patterns of spread of sexually transmitted diseases. To represent these two fundamental properties of sexual networks, we developed a stochastic process of dynamic partnership formation and dissolution, which results in power-law numbers of partners over time. Model parameters can be set to produce realistic conditions in terms of the exponent of the power-law distribution, of the number of individuals without relationships and of the average duration of relationships. Using an outbreak of antibiotic resistant gonorrhoea amongst men have sex with men as a case study, we show that our realistic dynamic network exhibits different properties compared to the frequently used static networks or homogeneous mixing models. We also consider an approximation to our dynamic network model in terms of a much simpler branching process. We estimate the parameters of the generation time distribution and offspring distribution which can be used for example in the context of outbreak reconstruction based on genomic data. Finally, we investigate the impact of a range of interventions against gonorrhoea, including increased condom use, more frequent screening and immunisation, concluding that the latter shows great promise to reduce the burden of gonorrhoea, even if the vaccine was only partially effective or applied to only a random subset of the population.