Malaria across borders: Measuring imported infections and contributions to local transmission in Uganda and Zimbabwe

跨境疟疾：衡量输入性感染及其对乌干达和津巴布韦当地传播的影响

• 批准号: 10280963
• 负责人: Isabel Rodríguez-Barraquer
• 金额: $ 70.45万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-16 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10280963
• 关键词: Adult; Africa South of the Sahara; Area; Behavioral; Cessation of life; Clinical Management; Collection; Data; Diagnosis; Epidemiology; Failure; Funding; Genomics; Geographic Locations; Geography; Health care facility; Household; Impact evaluation; Individual; Infection; Infrastructure; International; Interruption; Intervention; Longitudinal Studies; Malaria; Measures; Mozambique; Outcome; Parasites; Pattern; Plasmodium falciparum; Primary Infection; Recording of previous events; Reporting; Research; Residual state; Resources; Risk; Risk Factors; Role; Sampling; Site; Statistical Models; Surveillance Methods; Surveys; Testing; Travel; Uganda; United States National Institutes of Health; Zimbabwe; analytical method; base; design; epidemiologic data; genomic data; improved; international center; malaria infection; malaria transmission; predictive modeling; transmission process; vector control

PROJECT SUMMARY/ABSTRACT Malaria cases and deaths primarily caused by Plasmodium falciparum have declined significantly in sub- Saharan Africa as a result of the broad deployment of vector control and effective clinical management. In low to moderate-transmission settings slated for elimination, imported cases become an increasingly important epidemiological consideration. In these settings, imported cases may a) represent a high but poorly defined proportion of the overall malaria burden, b) result in secondary transmission that can impede local elimination efforts, and c) may require additional or alternative interventions than standard control measures. Imported cases, when currently evaluated at all, are operationally defined as infections acquired outside of a defined geographic area and identified based on travel history. However, lack of capture of asymptomatic infections together with variable quality of travel history collection limit the utility of this standard approach to identifying imported infections and quantifying their role in transmission. Further, there are no routinely collected data that would allow evaluation of the impact of imported cases on local transmission. In this proposal, we will collect detailed travel histories, perform active surveillance for asymptomatic infections, and generate parasite genomic data to more accurately define the role of imported infections in two representative border regions of sub-Saharan Africa (Tororo District, Uganda and Mutasa District, Zimbabwe) that leverage substantial surveillance infrastructure from the NIH-funded International Centers of Excellence for Malaria Research (ICEMR) network and will employ active (via a longitudinal study) and passive (via health facility surveillance) designs to capture asymptomatic and symptomatic infections. We propose the following Specific Aims.1) To quantify and characterize imported malaria infections. We will use a probabilistic approach to classify infections as imported or local via detailed travel and other behavioral survey data and determine the travel patterns and risk factors associated with importation. 2) To determine the impact of importation on local transmission and identify appropriate targeted interventions. We will use parasite genomics and epidemiological data to define local transmission and the impact of imported infections, taking advantage of dense sampling of symptomatic and asymptomatic infections in focused geographies. We will use a robust set of statistical modeling approaches, including Bayesian estimation of transmission networks incorporating all genomic and epidemiologic data. We will use these data to model the predicted impact of various combinations of targeted interventions. The expected outcome of the proposed research is evidence on appropriate surveillance methods for imported malaria infections and on the contribution of these infections to sustaining transmission. By identifying ways to better target interventions, these results will impact national and international malaria control efforts as they strive for elimination and require evidence on how to mitigate the risk of imported malaria infections.

项目摘要/摘要 主要由恶性疟原虫引起的疟疾病例和死亡人数在#年显著下降。 撒哈拉非洲由于广泛部署了病媒控制和有效的临床管理。处于低位 对于预定要消除的适度传播设置，输入病例变得越来越重要 流行病学方面的考虑。在这些设置中，导入的案例可能a)代表较高但定义不明确的 占疟疾总负担的比例，b)导致二次传播，可能阻碍当地消除 C)可能需要除标准控制措施之外的额外或替代干预措施。已导入 病例，当目前进行评估时，在操作上被定义为在定义的 地理区域，并根据旅行历史进行识别。然而，缺乏对无症状感染的捕获 再加上旅行历史收集的质量不稳定，限制了这种标准方法在识别 输入感染并量化其在传播中的作用。此外，没有常规收集的数据可以 将能够评估输入病例对当地传播的影响。在这份提案中，我们将收取 详细的旅行历史，对无症状感染进行主动监测，并产生寄生虫 基因组数据，以更准确地定义输入性感染在两个具有代表性的边境地区的作用 撒哈拉以南非洲(乌干达托罗罗区和津巴布韦穆塔萨区) 来自美国国立卫生研究院资助的国际疟疾研究英才中心的监测基础设施 (ICEMR)网络，并将采用主动(通过纵向研究)和被动(通过卫生设施监测) 旨在捕捉无症状和有症状的感染。我们建议以下具体目标1)以 量化和描述输入性疟疾感染情况。我们将使用概率方法对感染进行分类 通过详细的旅行和其他行为调查数据输入或本地，并确定旅行模式和 与进口有关的风险因素。2)确定输入对本地传播的影响以及 确定适当的针对性干预措施。我们将使用寄生虫基因组学和流行病学数据来确定 本地传播和输入性感染的影响，利用对症状的密集抽样 以及集中地区的无症状感染。我们将使用一组可靠的统计建模 方法，包括贝叶斯估计传输网络包括所有基因组和 流行病学数据。我们将使用这些数据对各种目标组合的预测影响进行建模 干预措施。拟议研究的预期结果是适当监督的证据。 关于输入性疟疾感染的方法以及这些感染对持续传播的贡献。 通过确定更好地针对干预措施的方法，这些结果将影响国家和国际疟疾。 在努力消除疟疾的同时进行控制努力，并要求提供证据说明如何减少输入性疟疾的风险 感染。