Yu Duo, Lin Qianying, Chiu Alice Py, He Daihai
Department of Applied Mathematics, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (SAR), China.
Department of Biostatistics, School of Public Health, University of Texas, Health Science Center at Houston, Houston, United States of America.
PLoS One. 2017 Jul 12;12(7):e0180545. doi: 10.1371/journal.pone.0180545. eCollection 2017.
The 1918 influenza pandemic was characterized by multiple epidemic waves. We investigated reactive social distancing, a form of behavioral response where individuals avoid potentially infectious contacts in response to available information on an ongoing epidemic or pandemic. We modelled its effects on the three influenza waves in the United Kingdom. In previous studies, human behavioral response was modelled by a Power function of the proportion of recent influenza mortality in a population, and by a Hill function, which is a function of the number of recent influenza mortality. Using a simple epidemic model with a Power function and one common set of parameters, we provided a good model fit for the observed multiple epidemic waves in London boroughs, Birmingham and Liverpool. We further applied the model parameters from these three cities to all 334 administrative units in England and Wales and including the population sizes of individual administrative units. We computed the Pearson's correlation between the observed and simulated for each administrative unit. We found a median correlation of 0.636, indicating that our model predictions are performing reasonably well. Our modelling approach is an improvement from previous studies where separate models are fitted to each city. With the reduced number of model parameters used, we achieved computational efficiency gain without over-fitting the model. We also showed the importance of reactive behavioral distancing as a potential non-pharmaceutical intervention during an influenza pandemic. Our work has both scientific and public health significance.
1918年流感大流行的特点是出现多波疫情。我们研究了反应性社交距离，这是一种行为反应形式，个体根据有关正在发生的疫情或大流行的现有信息，避免与可能具有传染性的人接触。我们模拟了其对英国三次流感疫情波的影响。在先前的研究中，人类行为反应是通过人群中近期流感死亡率比例的幂函数以及近期流感死亡人数的希尔函数来建模的。使用一个具有幂函数和一组通用参数的简单疫情模型，我们对伦敦各区、伯明翰和利物浦观察到的多波疫情提供了良好的模型拟合。我们进一步将这三个城市的模型参数应用于英格兰和威尔士的所有334个行政单位，并纳入了各个行政单位的人口规模。我们计算了每个行政单位观察值与模拟值之间的皮尔逊相关性。我们发现中位数相关性为0.636，表明我们的模型预测表现相当不错。我们的建模方法是对先前研究的改进，先前研究是为每个城市分别拟合模型。通过减少使用的模型参数数量，我们在不过度拟合模型的情况下提高了计算效率。我们还展示了反应性行为距离作为流感大流行期间潜在非药物干预措施的重要性。我们的工作具有科学和公共卫生意义。
