Snail-Related Studies of Transmission & Control of Schistosomiasis in Kenya

项目总结/摘要 在继续折磨世界人口中“最底层10亿人”的被忽视的热带病中， 血吸虫病是最常见的疾病之一（目前有2.58亿例），也是最难控制的疾病。次 撒哈拉非洲现在支持世界上85%以上的血吸虫病病例，这种疾病长期以来一直是 它对感染者，通常是贫困儿童的影响被低估了。世卫组织呼吁， 到2025年消除人类血吸虫病这一公共卫生问题， 一种可用的药物吡喹酮仍将是这一努力的支柱，已达成共识， 如果我们要实现世界卫生组织雄心勃勃的目标， 目标.没有任何地方的血吸虫病控制的前景比非洲五大湖更令人生畏， 曼氏血吸虫在维多利亚湖和阿尔伯特湖繁殖， 栖息地至少有三个分类群的双脐螺。建立在与联合国 根据新墨西哥州大学和肯尼亚医学研究所的研究，我们假设， 这三种蜗牛类群之间的差异导致了与寄生虫和其他寄生虫的相容性的差异。 寄生虫，并为每个分类群创造不同的机会，控制幼虫阶段的S。曼索尼说， 可以在其中传播。我们提出了三个目标：目标1）揭示和剖析不同的角色， 双脐螺在传播沙门氏菌方面存在明显的生物学差异。mansoni in six代表 维多利亚湖盆地的传播点。这三个类群是B。苏丹（一个外交叉，海岸线， 栖息种），B. choanomphala（B. sudanica）和B. pfeifferi（一个自我- （2）确定和利用非生物多样性， 在维多利亚湖流域的一些双殖吸虫中，它们与S.曼氏菌感染 3）开发新的方法来控制蜗牛或幼虫的寄生虫， 像维多利亚湖这样的传播点。这些尝试将包括识别和测试可疑的- 耐药蜗牛和CRISPR/Cas技术与非洲双脐螺的发展， 知识最终可用于多种目的，包括控制蜗牛的新方法。我们 拟议的研究提供了发展钉螺控制的前景， 血吸虫病控制战略，开发当地资源，可以扩大规模，并在低技术应用 方法，并为美国和肯尼亚的年轻调查人员提供关键培训，以应对面临的挑战。 以蜗牛为中心的血吸虫病控制。

PROJECT SUMMARY/ABSTRACT Among the Neglected Tropical Diseases that continue to afflict the “bottom billion” of the world's population, schistosomiasis ranks as one of the most common (currently 258 million cases) and difficult to control. Sub- Saharan Africa now supports over 85% of the world's cases of schistosomiasis, a disease that has long been underestimated in its impact on the people it infects, often impoverished children. The WHO has called for the elimination of human schistosomiasis as a public health problem by 2025, and although chemotherapy with the one available drug praziquantel will remain the backbone of this effort, a consensus has emerged that integrated control approaches (including snail control) will be needed if we are to achieve the WHO's ambitious goals. Nowhere is the prospect for schistosomiasis control more daunting than in the African great lakes like Lake Victoria and Lake Albert in which Schistosoma mansoni thrives, being transmitted in and around such habitats by at least three taxa of Biomphalaria snails. Building on a long-standing partnership between the University of New Mexico and the Kenya Medical Research Institute, we hypothesize that inherent biological differences among the three snail taxa lead to differences in compatibility with schistosomes and other parasites, and create for each taxon distinct opportunities for controlling the larval stages of S. mansoni that can propagate within them. We propose three aims: Aim 1) To reveal and dissect the roles of different Biomphalaria taxa with marked biological differences in the transmission of S. mansoni in six representative transmission sites in the Lake Victoria basin. The three taxa are B. sudanica (an out-crossing, shoreline- inhabiting species), B. choanomphala (a deep water ecophenotype of B. sudanica) and B. pfeifferi (a self- fertilizing snail usually in streams leading into the lake); Aim 2) To define and exploit the biodiversity of non- schistosome digeneans in the Lake Victoria basin, to compete with and suppress S. mansoni infections within Biomphalaria; and Aim 3) To develop novel approaches for snail or larval schistosome control scalable to vast transmission sites like Lake Victoria. These attempts will include identification and testing of schistosome- resistant snails and development of CRISPR/Cas technology with African Biomphalaria snails such that the knowledge can eventually be exploited for multiple purposes, including novel approaches for snail control. Our proposed studies offer the prospect of developing snail control that can be synchronized with integrated schistosomiasis control strategies, exploit local resources that could be scaled up and applied in low tech ways, and provide key training for young investigators in both the U.S. and Kenya for the challenges that lie ahead for snail-centered schistosomiasis control.