西非三国埃博拉疫情防控措施效率的研究

发布时间：2018-09-12 07:42

【摘要】：从2014年2月开始,在西非几内亚爆发的埃博拉病,是近40年来爆发的一次最大规模的疫情,对西非及其他地区造成了严重威胁。西非三国(几内亚、利比里亚、塞拉利昂)是全球疫情最严重的区域,集中了全球99.9%以上的病例。在世界卫生组织及其他医疗团体的帮助下,西非三国疫情防控措施得以有效实施,为疫情的最终控制起到了关键性作用。本文在已有动力学模型的基础上,建立了符合西非埃博拉病毒传播实际情况的传染病动力学模型,分别从SEIR相关模型和具有隔离仓室的模型两个方面来研究和分析西非三国疫情防控措施的效率。本文的主要工作有以下几点:(1)基于SEIR模型,结合世界卫生组织公布的埃博拉数据,我们从模型中得到西非三国在埃博拉初期无控制状态下的传染率的取值。通过得到的数值结果,进而对疫情的发展趋势进行预测,结果体现了埃博拉防控工作的紧迫性和重要性。(2)鉴于埃博拉疫情不同时段的防控措施强度的差异,我们定义分段函数b(t)建立新的模型,得到三国控制因子k1和k2的取值。然后,我们对所得的数据进行横向比较,分析结果所反映的三国防控措施效率的差异,得到结论:利比里亚防控措施强度最大、塞拉利昂次之、几内亚最小,所得结果与实际情况相吻合,从而验证了所得结论的正确性。(3)基于埃博拉发病前后所采取的防控手段的不同,我们建立了能够较好地反映实际情况的SE_gE_qE_(gg)I_gI_qI_(gg)I_(gq)R模型和SE_gE_qI_gI_qI_(gq)R模型,得到模型中的未知参数a_1、a_2、c_1和c_2的取值。通过数据分析,我们对西非三国在具体分类下的预防措施和控制措施效果分别进行评估和横向整体比较。然后,我们进行综合评价,得到结论:利比里亚防控措施强度最大、塞拉利昂次之、几内亚最小。最后,我们对参数的敏感性进行了分析。我们从模型得到的结果与世界卫生组织公布的感染数据拟合度较高,而且评估结果也与实际相吻合,通过定量分析较好的揭示了三国疫情防控工作的效率。本文的研究对评定防控措施的有效性具有一定的借鉴意义,从而对如何采取较为有效的防控策略具有一定的指导意义。
[Abstract]:The Ebola outbreak in Guinea in West Africa, which began in February 2014, is the largest outbreak in nearly 40 years and poses a serious threat to West Africa and beyond. Three countries in West Africa (Guinea, Liberia, Sierra Leone) are the world's most severely affected regions, accounting for more than 99.9 percent of the world's cases. With the help of the World Health Organization (WHO) and other medical organizations, the prevention and control measures of the epidemic in West Africa have been effectively implemented, which has played a key role in the final control of the epidemic. Based on the existing kinetic models, the epidemic dynamics model of Ebola virus transmission in West Africa has been established in this paper. The efficiency of epidemic prevention and control measures in three West African countries was studied and analyzed from two aspects: SEIR model and model with isolation chamber. The main work of this paper is as follows: (1) based on the SEIR model and the Ebola data published by the World Health Organization, we get the transmission rate of the three West African countries in the initial stage of Ebola uncontrolled. The result shows the urgency and importance of Ebola prevention and control work. (2) considering the difference of the intensity of prevention and control measures in different period of Ebola epidemic situation, We define the piecewise function b (t) to establish a new model and obtain the values of the control factors K1 and K2 of the three countries. Then, we compare the data obtained horizontally, and analyze the differences in the efficiency of preventive and control measures among the three countries. The conclusion is: Liberia has the highest intensity of preventive and control measures, Sierra Leone is the second, Guinea is the smallest. The results are in agreement with the actual situation, which verifies the correctness of the conclusions. (3) based on the difference of prevention and control methods before and after Ebola onset, we have established the SE_gE_qE_ (gg) IgI _ (gg) I _ (gq) R model and SE_gE_qI_gI_qI_ (gq) R model, which can reflect the actual situation well. The values of the unknown parameters a _ S _ 1 / a _ 2C _ S _ 1 and C _ 2 in the model are obtained. Based on the data analysis, we evaluate and compare the effects of preventive measures and control measures in three West African countries respectively. Then, we conducted a comprehensive evaluation and concluded that Liberia has the greatest intensity of preventive and control measures, Sierra Leone second and Guinea the smallest. Finally, we analyze the sensitivity of the parameters. The results obtained from the model are in good agreement with the infection data published by the World Health Organization, and the evaluation results are in good agreement with the actual situation. The efficiency of epidemic prevention and control in the three countries is revealed by quantitative analysis. The research in this paper has certain reference significance to evaluate the effectiveness of prevention and control measures, thus has certain guiding significance to how to adopt more effective prevention and control strategy.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O175

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