Gao Xiaolei, Wei Jianjian, Lei Hao, Xu Pengcheng, Cowling Benjamin J, Li Yuguo
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
Institute of Applied Mathematics, Academy of Mathematics and Systems Sciences, Chinese Academy of Sciences, Beijing, China.
PLoS One. 2016 Sep 9;11(9):e0162481. doi: 10.1371/journal.pone.0162481. eCollection 2016.
Emerging diseases may spread rapidly through dense and large urban contact networks, especially they are transmitted by the airborne route, before new vaccines can be made available. Airborne diseases may spread rapidly as people visit different indoor environments and are in frequent contact with others. We constructed a simple indoor contact model for an ideal city with 7 million people and 3 million indoor spaces, and estimated the probability and duration of contact between any two individuals during one day. To do this, we used data from actual censuses, social behavior surveys, building surveys, and ventilation measurements in Hong Kong to define eight population groups and seven indoor location groups. Our indoor contact model was integrated with an existing epidemiological Susceptible, Exposed, Infectious, and Recovered (SEIR) model to estimate disease spread and with the Wells-Riley equation to calculate local infection risks, resulting in an integrated indoor transmission network model. This model was used to estimate the probability of an infected individual infecting others in the city and to study the disease transmission dynamics. We predicted the infection probability of each sub-population under different ventilation systems in each location type in the case of a hypothetical airborne disease outbreak, which is assumed to have the same natural history and infectiousness as smallpox. We compared the effectiveness of controlling ventilation in each location type with other intervention strategies. We conclude that increasing building ventilation rates using methods such as natural ventilation in classrooms, offices, and homes is a relatively effective strategy for airborne diseases in a large city.
新发疾病可能会在密集且庞大的城市接触网络中迅速传播，尤其是在新型疫苗可用之前通过空气传播途径传播的疾病。随着人们前往不同的室内环境并与他人频繁接触，空气传播疾病可能会迅速传播。我们构建了一个针对拥有700万人口和300万个室内空间的理想城市的简单室内接触模型，并估算了一天内任意两个人之间接触的概率和持续时间。为此，我们使用了来自香港实际人口普查、社会行为调查、建筑调查和通风测量的数据来定义八个群体和七个室内场所类型。我们的室内接触模型与现有的流行病学易感、暴露、感染和康复（SEIR）模型相结合以估算疾病传播，并与韦尔斯-莱利方程相结合以计算局部感染风险，从而形成一个综合的室内传播网络模型。该模型用于估算城市中受感染个体感染他人的概率，并研究疾病传播动态。我们预测了在假设的空气传播疾病爆发情况下，每种场所类型在不同通风系统下每个亚群体的感染概率，假设该疾病具有与天花相同的自然史和传染性。我们将每种场所类型控制通风的有效性与其他干预策略进行了比较。我们得出结论，在大城市中，使用如教室、办公室和家庭中的自然通风等方法提高建筑物通风率是应对空气传播疾病的一种相对有效的策略。
