我国边境疟疾传播扩散机制模型的研究

As one of the serious vector-borne diseases in the world, malaria's transmission and diffusion is affected by several factors, including biological, environmental, and socioeconomic factors. Existing malaria transmission models mainly have focused on Plasmodium falciparum malaria in high-transmission areas of Africa, while few studies on the transmission mechanism and relationship between human population and the infections with plasmodium parasites in low-transmission regions. Due to little investigation on issues in the increasing numbers of the imported malaria cases annually in the border area of Yunnan province as well as the association between population with the plasmodium parasite without symptoms and the force of infection in mosquito vectors, we are trying to conduct the epidemiological and biological studies based upon our previous research results on transmission models of infectious diseases, the mobility features of population and mosquito vectors, as well as historically databases of infected cases. Then, the determinates of malaria transmission and diffusion network in the border area of Yunnan province will be identified, and the malaria transmission mechanism model and diffusion network model will be developed on the line with the force of infection and mobility in infected population without symptom and mosquito vectors. Furthermore, the computational optimization problem of inferring the underlying diffusion network will be formulated under the view of temporal-spatial scales. Finally, the role of the force of infction in population and mosquito vectors in low-transmission area will be explored. The significance of this project lies in that it will provide theoretical foundations to understand and predict malaria transmission patterns and diffusion networks in the future, which will support the real-time surveillance system in the course of malaria elimination program along the border area in the country.

疟疾为全球最严重的虫媒传染病之一，传播扩散过程受环境、社会、生物等多种因素的影响。以往的疟疾传播机制数学模型研究大多集中在非洲高流行区恶性疟的研究，忽略了低流行区疟疾传播机制、人群与疟原虫感染之间关系的研究。本研究将针对云南边境地区跨国境输入性疟疾病例逐年增多而成为我国消除疟疾关键地区、以及无症状带虫者人群与蚊虫传染力相互关系的研究较少等问题，综合利用我们前期的传染病传播模型研究成果以及云南边境地区的人群与蚊虫流动性、历史疫情等数据，开展流行病学调查以及生物学实验研究，确定影响云南边境地区疟疾传播及扩散的因素，并以无症状带虫者人群与蚊虫感染力、人群与蚊虫流动性为核心，构建疟疾传播的机制模型和疟疾传播扩散网络模型，推演出随时空变化的疟疾传播潜在方式，阐明疟疾传播扩散过程中人群与蚊虫间传染力的作用，为预测疟疾传播和扩散方式提供理论依据，并为边境地区消除疟疾过程中实时监测疟疾扩散提供实践基础。

本研究针对了中国云南边境地区跨国境输入性疟疾病例逐年增多、以及无症状带虫者人群与蚊虫传染力相互关系的研究较少等问题，综合利用了我们前期的传染病传播模型研究成果以及云南边境地区的人群与蚊虫流动性、历史疫情等数据，开展了流行病学调查以及生物学实验研究，主要完成了以下研究工作：1）建立我国云南边境传播机制模型以及扩散网络模型的基础数据库；2）采用生物学实验等方法阐明疟疾传播机制与扩散网络模型中关键参数的研究；3）构建我国云南边境疟疾传播机制模型；4）人群与蚊虫流动性以及疟疾扩散网络的推演；5）云南边境地区疟疾传播以及扩散方式的分析。. 通过以上5个方面的研究工作，确定了影响云南边境地区疟疾传播及扩散的因素，并在掌握无症状带虫者人群与蚊虫感染力、人群与蚊虫流动性的基础上，构建疟疾传播的机制模型和疟疾传播扩散网络模型，推演出了随时空变化的疟疾传播潜在方式，阐明了疟疾传播扩散过程中人群与蚊虫间传染力的作用，为预测疟疾传播和扩散方式提供理论依据，并直接指导了边境地区消除疟疾过程中的实时监测疟疾关键技术。