中国基孔肯雅热暴发疫情关键控制措施效果模拟

A model for evaluation of key measures for control of chikungunya fever outbreak in China

目的 应用常微分方程（ODE）模型研究基孔肯雅热（CHIK）在社区暴发及流行的传播动力学规律,并评价灭蚊、病例隔离等关键控制措施的效果.方法 根据CHIK的疾病自然史建立适合CHIK暴发特点的ODE模型.收集中国CHIK暴发疫情数据,将模型与实际疫情数据拟合,获得模型关键参数,模拟无干预情况下的暴发疫情特点.然后加入灭蚊和隔离措施,评价不同干预措施的防控效果.结果 ODE模型显示,在无干预的情况下,在11 000人的社区中输入1例病例,累计发病人数将超过941人,罹患率超过8.55％.不同时间采取隔离措施,结果显示,由于病毒已经在蚊虫中持续存在了一定时间,隔离效果不理想,发病人数和自然状态相比虽有降低,但疫情持续时间却未见减少;不同时间采取灭蚊措施,防控效果显著,越早灭蚊,效果越好;＆quot;灭蚊＋隔离＆quot;措施的效果与只采取灭蚊措施的效果相同.结论 在CHIK的暴发疫情处置中,最重要的防控措施为灭蚊,但在不能杀灭所有蚊虫时需要采取病例防蚊隔离措施.

Objective To analyze the transmission pattern of Chikungunya （CHIK） fever in community and evaluate the effectiveness of mosquito control, case isolation and other key control measures by using ordinary differential equation （ODE） model.Methods According to natural history of CHIK, an ODE model for the epidemiological anaysis of CHIK outbreak was established.The key parameters of the model were obtained by fitting the model with reported outbreak data of the first CHIK outbreak in China.Then the outbreak characteristics without intervention, the effectiveness of mosquito control and case isolation were simulated.Results Without intervention, an imported case would cause an outbreak in a community with population of 11 000, and cumulative case number would exceed 941 when the total attack rate was 8.55%.The results of our simulation revealed that the effectiveness of case isolation was not perfect enough when it was implemented alone.Although the number of cases could be decreased by case isolation, the duration of outbreak would not be shortened.Differently, the effectiveness of mosquito control was remarkable.In addition, the earlier the measure was implemented, the better the effectiveness would be.The effectiveness of mosquito control plus case isolation was same with mosquito control.Conclusion To control a CHIK outbreak, mosquito control is the most recommended measures.However, case isolation is also necessary as the supplementation of mosquito control.