Community-directed vector control to enhance mass drug administration for onchocerciasis elimination in Africa

摘要 盘尾丝虫病或河盲症是公认的被忽视的人类热带疾病之一。的 疾病是由丝虫寄生虫盘尾丝虫引起的，盘尾丝虫通过黑蝇（Simuelus）传播 spp）。在20世纪80年代，伊维菌素首次被证明是一种有效的杀微丝蚴剂。肠扭转作为 因此，国际计划开始控制或消除盘尾丝虫病，采用 向受影响社区大规模施用伊维菌素的战略。长期基于MDA 这些方案已使盘尾丝虫病从非洲的一些疫源地和非洲的几乎所有疫源地中消除。 拉美这些成功导致重点从疾病控制的目标， 《关于被忽视的热带气旋的伦敦宣言》 该计划确定了到2020年在非洲消除盘尾丝虫病的目标。尽管取得了这些成功， 单靠MDA可能不足以及时中断非洲许多地区的传播， 伦敦宣言的目标，可能无法中断在所有地方的传播媒介 密度很高。在这些领域，有必要以其他干预措施补充MDA。的 乌干达的经验表明，综合利用病媒控制和 伊维菌素MDA可阻断O.在该国的9个肠扭转 短短7年内就有17个病灶。然而，黑蝇控制传统上依赖于对病媒进行杀虫剂处理， 繁殖地点，这是一种昂贵且后勤困难的方法。在这里，我们提出了一个不同的 的黑蝇媒介的控制范例。肠扭转，即涉及患病社区， 这个过程这个项目是最近项目的产物（1）开发一个黑蝇陷阱，以取代 人类登陆收集的昆虫监测O。扭转传播，（2）发展一个 一种能够预测媒介黑蝇繁殖生境的遥感算法。第一个项目导致 在Esperanza Window Trap（EWT）的开发中， 廉价的材料，这等于或超过执行一个人类登陆队的收集载体 物种EWT可以成功地由当地居民操作，并已被证明显着 降低咬人率。在第二项努力中，我们进行了初步研究，证明 动员当地居民清除被发现的病媒滋生地的蔓生植物， 叮咬率超过80%在本项目中，将通过以下组合评估总体假设： 田间试验和数学建模研究的一个重要方面是，社区定向病媒控制努力 使用优化的诱捕器，局部减少繁殖栖息地或这些措施的某种组合将减少媒介 咬率达到一个点，O.肠扭转可以通过共同给予MDA来消除，即使在 其中矢量密度高。

ABSTRACT Onchocerciasis, or river blindness, is one of the recognized neglected tropical diseases of mankind. The disease is caused by the filarial parasite Onchocerca volvulus, which is spread by black flies (Simulium spp). In the 1980s, ivermectin was first shown to be a potent microfilaricide against O. volvulus. As a result, international programs were begun to either control or eliminate onchocerciasis, employing a strategy of mass drug administration (MDA) of ivermectin to afflicted communities. Long term MDA based programs have resulted in the elimination of onchocerciasis from some foci in Africa and almost all foci in Latin America. These successes have resulted in a change in focus from a goal of disease control of onchocerciasis to a goal of elimination, enshrined in the London Declaration on Neglected Tropical Diseases, which set a goal of eliminating onchocerciasis from Africa by 2020. Despite these successes, MDA alone will probably not be sufficient to interrupt transmission in many regions of Africa in time to meet the London Declaration goals, and may not be capable of interrupting transmission at all where vector densities are high. In such areas, it will be necessary to supplement MDA with other interventions. The experience of Uganda has demonstrated the power of utilizing a combination of vector control and ivermectin MDA, which has resulted in the interruption of transmission of O. volvulus in 9 of the country’s 17 foci in just 7 years. However, black fly control has traditionally relied upon insecticide treatment of vector breeding sites, an approach that is expensive and logistically difficult. Here we propose a different paradigm for the control of the black fly vectors of O. volvulus, that of involving the afflicted communities in this process. This project is an outgrowth of recent projects (1) to develop a black fly trap to replace human landing collections for entomological monitoring of O. volvulus transmission and, (2) to develop a remote sensing algorithm capable of predicting vector black fly breeding habitats. The first project resulted in the development of the Esperanza Window Trap (EWT), a platform constructed from locally available inexpensive materials, which equals or out performs a human landing team for the collection of vector species. The EWT can be successfully operated by local residents and has been shown to significantly reduce biting rates. In the second effort, we have conducted preliminary studies that demonstrate that enlisting local residents to remove trailing vegetation from detected vector breeding sites can reduce local biting rates by over 80%. The overall hypothesis that will be evaluated in this project through a combination of field experiments and mathematical modeling studies is that community directed vector control efforts using optimized traps, local reduction of breeding habitat or some combination of these will reduce vector biting rates to a point where O. volvulus may be eliminated by co-administration of MDA, even in areas where vector density is high.