Department of Epidemiology, University of Michigan - Ann Arbor, USA.
Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.
Epidemics. 2010 Sep;2(3):155-164. doi: 10.1016/j.epidem.2010.06.003. Epub 2010 Jun 19.
The risk of acquiring sexually transmitted infections (STIs) depends on individual behavior and the network of risky partnerships in which an individual participates. STI epidemics often spread rapidly and primarily among individuals central to transmission networks; and thus they often defy the mass-action principle since incidence is not proportional to the infectious fraction of the population. Here, we estimate the contact network structure for an Atlanta, Georgia community with heterogeneous sexual and drug-related risk behaviors and build a detailed transmission model for HIV through this population. We show that accurate estimation of epidemic incidence requires careful measurement and inclusion of diverse factors including concurrency (having multiple partners), the duration of partnerships, serosorting (preference for partners with matching disease state), and heterogeneity in the number and kinds of partners. In the focal population, we find that injection drug users (IDUs) do not directly cause many secondary infections; yet they bridge the heterosexual and men-who-have-sex-with-men (MSM) populations and are thereby indirectly responsible for extensive transmission.
性传播感染（STIs）的风险取决于个人行为和个人参与的风险伙伴关系网络。性传播感染疫情通常传播迅速，主要发生在传播网络中的核心个体中；因此，它们往往违背大规模行动原则，因为发病率与人群中的感染部分不成比例。在这里，我们估计了佐治亚州亚特兰大市具有不同性和与毒品相关的风险行为的社区的接触网络结构，并通过该人群构建了 HIV 的详细传播模型。我们表明，准确估计疫情发病率需要仔细测量和纳入多种因素，包括并发（拥有多个伴侣）、伴侣关系的持续时间、血清型选择（对具有匹配疾病状态的伴侣的偏好）以及伴侣数量和种类的异质性。在焦点人群中，我们发现注射吸毒者（IDUs）并没有直接导致许多二次感染；然而，他们将异性恋者和男男性行为者（MSM）群体联系起来，因此间接导致了广泛的传播。
