Epidemiology

该项目的长期目标是为制定进一步减少南部非洲疟疾传播的可持续战略提供证据基础，并通过综合了解当地疟疾流行病学、病媒生物学、寄生虫种群结构以及社区和家庭一级的信仰和行动，评估消除疟疾的可行性。在位于赞比亚南部农村乔马区的约翰霍普金斯疟疾研究所实地站点作为疟疾研究的区域卓越中心的基础上，我们建议通过前瞻性的医院、临床和社区研究，在南部非洲三个反映疟疾控制不同阶段(成功-乔马、无效-挑战、复活-穆塔萨)的不同传播环境中研究疟疾流行病学的变化，以解决以下问题：目的1)测量南部非洲三个不同流行病学环境中疟疾寄生虫病时空模式的变化，并确定每个环境中有症状和无症状寄生虫病的个人、家庭和生态风险因素；目的2)在南部非洲三个不同的流行病学环境中，确定在高传播期和低传播期配子体携带的个人、家庭和生态危险因素；目的3)利用南部非洲三个地区的血清流行病学调查，测量特定年龄和抗体对恶性疟原虫免疫应答的时空变化；目的4)利用数学建模方法，以当地现有的调查和监测数据为基础，确定有针对性的、基于风险的疟疾控制策略组合，以优化决策算法。因此，详细了解疟疾在三种不同流行病学环境中的传播动态将有助于制定适合当地情况、成本效益高和社区支持的疟疾控制战略。 这些流行病学研究将与应对生态变化和疟疾控制努力的按蚊媒介和疟原虫种群结构的时空变化研究密切相关。这种综合的、以证据为基础的疟疾控制方法将构成南部非洲疟疾研究区域卓越中心的基础，也是区域消除疟疾的基础。

The long-term project goal is to provide the evidence-base for the development of sustainable strategies to further reduce malaria transmission in southern Africa and assess the feasibility of malaria elimination through an integrated understanding of local malaria epidemiology, vector biology, parasite populafion structure and community and household-level beliefs and actions. Building upon the Johns Hopkins Malaria Research Institute field site in Choma District in rural southern Zambia as a regional center of excellence in malaria research, we propose to invesfigate the changing epidemiology of malaria in three disfinct transmission settings in southern Africa reflecting different stages of malaria control (successful - Choma, ineffective - Nchelenge, resurgent - Mutasa) through prospective hospital, clinic and community-based studies to address the following: Aim 1) Measure changes in spafio-temporal patterns of malaria parasitemia in three disfinct epidemiological settings in southern Africa and identify individual, household and ecological risk factors for symptomafic and asymptomatic parasitemia in each setting; Aim 2) Identify individual, household and ecological risk factors for gametocyte carriage during high and low transmission seasons in three disfinct epidemiological settings in southern Africa; Aim 3) Measure spatio-temporal changes in agespecific anfibody responses to Plasmodium falciparium anfigens using sero-epidemiological surveys in the three regions of southern Africa; Aim 4) Idenfify targeted, risk-based combinations of malaria control strategies that are cost-effective and acceptable to the community using mathematical modeling approaches to optimize decision algorithms based on locally available survey and surveillance data. Detailed understanding of malaria transmission dynamics in three different epidemiological settings will thus inform the development of locally-adapted, cost-effective and community-supported strategies for malaria control. These epidemiological invesfigafions will be closely linked with studies of spafio-temporal changes in the anopheline vector and Plasmodium populafion structure in response to ecological changes and malaria control efforts. This integrated, evidence-based approach to malaria control will form the foundation for a regional center of excellence for malaria research in southern Africa and the foundation for regional malaria eliminafion.