Determinants of Schistosomiasis Re-emergence

描述（由申请人提供）：我们对中国日本血吸虫感染的传播和控制研究的广泛长期目标是开发设计特定地点控制计划的方法，以实现可持续的停止传播。最近在前控制县重新出现传播促使我们提出了这一提议，其中我们将我们的目标扩展到包括了解重新出现的决定因素，这将为设计监测计划提供依据，以便及早发现并最大限度地减少重新出现的规模和影响。我们研究的目的是 1. 检验重新出现是由两个村庄层面的因素驱动的假设：内部潜力（村庄支持传播的固有能力，包括蜗牛密度、人类和动物宿主以及农业实践）和连通性（与从流行地区引入寄生虫有关的因素），这可以从现有的历史记录和遥感中获得； 2. 使用病例对照研究，检验以下假设：村内和村外的个人层面的水接触可以预测重新出现的村庄的初始感染； 3. 利用重新出现传播的随机模型来探索偶然事件对有效监测系统设计的影响。与公共卫生的相关性：这项研究与公共卫生相关，因为它将增加我们对与传染病重新出现相关的因素的了解。通过这种理解，可以开发更好的监测方法来保护公众健康。

DESCRIPTION (provided by applicant): The broad long-term objectives of our research on the transmission and control of Schistosoma japonicum infections in China have been to develop methods for the design of site-specific control programs to achieve the sustainable cessation of transmission. The recent re-emergence of transmission in formerly controlled counties has prompted this proposal, in which we extend our objectives to include an understanding of the determinants of re-emergence, which will inform the design of surveillance programs for the early detection and minimization of the scale and impact of re-emergence. The aims of our research are to 1. Test the hypothesis that re-emergence is driven by two village-level factors: internal potential (a village's inherent ability to support transmission that includes snail density, human and animal hosts, and agricultural practices) and connectivity (factors related to the introduction of parasites from endemic areas), which can be obtained from existing historical records and remote sensing; 2. Using a case-control study, test the hypothesis that individual-level within-village and outside-village water contact is predictive of the initial infections in re-emergent villages; and 3. Utilize a stochastic model of re-emergent transmission to explore the effect of chance events on the design of an effective surveillance system. Relevance to public health: This research is relevant to public health, in that it will increase our knowledge of the factors related to infectious disease re-emergence. Through this understanding, better surveillance approaches can be developed to protect public health.