Legrand J, Viboud C, Boelle P Y, Valleron A J, Flahault A
Epidemiology and Information Sciences, INSERM U444, CHU Saint-Antoine, Université Pierre et Marie Curie, 27 rue Chaligny, 75012 Paris, France.
Epidemiol Infect. 2004 Jan;132(1):19-25. doi: 10.1017/s0950268803001390.
Epidemiology and modelling are currently under pressure to build consistent scenarios of control in case of deliberate release of biological weapons. In order to assess the key parameters for the control of a smallpox outbreak in a large city (2 million inhabitants), we built a stochastic model to simulate the course of an epidemic controlled by ring vaccination and case isolation. Assuming a reference scenario with 100 index cases and implementation of intervention 25 days after the attack, the model forecasts an epidemic of 730 cases with an epidemic duration of 240 days. Setting intervention 20 days later would result in an almost fourfold increase in the epidemic size. A multivariate sensitivity analysis has selected three key parameters: the basic reproduction number (i.e. the number of secondary cases infected by one case in an entirely susceptible population, equal to 3 in the reference scenario), time to intervention, and proportion of traced and vaccinated contacts.
目前，流行病学和建模面临着压力，需要构建在生物武器蓄意释放情况下一致的控制方案。为了评估控制大城市（200万居民）天花疫情的关键参数，我们构建了一个随机模型来模拟通过环状疫苗接种和病例隔离控制的疫情过程。假设参考情景为有100例索引病例，并在袭击后25天实施干预，该模型预测疫情将有730例，疫情持续时间为240天。将干预时间推迟20天会导致疫情规模几乎增加四倍。多变量敏感性分析选择了三个关键参数：基本再生数（即在完全易感人群中一个病例感染的二代病例数，在参考情景中等于3）、干预时间以及追踪和接种疫苗的接触者比例。
