The elimination of the vector Simulium neavei from the Itwara onchocerciasis focus in Uganda by ground larviciding
The elimination of the vector Simulium neavei from the Itwara onchocerciasis focus in Uganda by ground larviciding
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DOI：
10.1016/j.actatropica.2009.04.001
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发表时间：
2009-09-01
期刊：
影响因子：
2.7
通讯作者：
Amazigo, U. V.
中科院分区：
文献类型：
--
作者：
Garms, R.;Lakwo, T. L.;Amazigo, U. V.
伊特瓦拉盘尾丝虫病疫源地位于乌干达西部，位于波特尔堡以北约20公里处，占地约600公里。媒介是尼维西姆，它的幼虫和蛹生活在淡水蟹上的磷协会。伊特瓦拉疫源地的磷宿主是蟹类。在任何盘尾丝虫病控制之前，估计每年每个人感染幼虫的数量在4500到6500之间。纽氏链霉菌是一种非常有效的媒介，40%的产后苍蝇携带螺旋体盘尾丝虫的发育幼虫。经过4年的社区传播，伊维菌素的传播仍然很大，1995年开始在三个分病区中的第一个分病区对溪流进行每月用杀幼虫剂敌敌畏的治疗，并逐渐扩大到整个病区。咬人的S.neavei于1996年6月从第一个分焦点(Itwara Main)消失，最后一只出没的螃蟹是在1996年11月捕获的。在第二次分焦点治疗(SIISA)中，1995年底开始治疗，1997年3月捕获了最后一只叮咬苍蝇，但安全局势的恶化中断了方案(在第三次分重点治疗中只进行了三次治疗)。1998年9月，在第二和第三亚疫区(ASWA)重新开始每月治疗，2003年重新评估情况时，任何地方都没有发现叮咬苍蝇，苍蝇也没有再次侵入第一亚疫区，但在第二和第三亚疫区发现了受感染的螃蟹。最后一次治疗是在2003年4月至6月进行的，自那以来没有发现有感染的螃蟹。总而言之，自2003年6月以来，在疫源地的任何地方都没有发现感染新城疫的螃蟹，该媒介被认为从该日期起被消灭。然而，自2001年2月以来，传播已经停止。当最后一批咬人的苍蝇被收集起来的时候。到2016年，人类群体中的寄生虫库应该会消失。(C)2009爱思唯尔B.V.保留所有权利。
The Itwara focus of onchocerciasis covers an area of approximately 600 km(2) in western Uganda about 20 km north of Fort Portal. The vector is Simulium neavei, whose larvae and pupae live in a phoretic association on freshwater crabs. The phoretic host in the Itwara focus is the crab Potamonautes aloysiisabaudiae. Before any onchocerciasis control, ATPs were estimated to reach between 4500 and 6500 infective larvae per person per year. S. neavei was found to be a very efficient vector with 40% of parous flies harbouring developing larvae of Onchocerca volvulus. After 4 years of community-based distribution of ivermectin transmission was still considerable and in 1995 monthly treatment of streams with the larvicide temephos commenced in the first of three sub-foci, and was gradually extended to the whole focus. Biting S. neavei disappeared from the first sub-focus (Itwara main) in June 1996, and the last infested crab was caught in November 1996. In the second sub-focus (Siisa) treatment commenced towards the end of 1995, and the last biting fly was caught in March 1997, but a deterioration in the security situation interrupted the programme (after only three treatments in the third sub-focus). Monthly treatments restarted in the second and third sub-foci (Aswa) in September 1998, and when the situation was reassessed in 2003 no biting flies were found anywhere, and the flies had not reinvaded the first sub-focus, but infected crabs were found in the second and third sub-foci. The last treatments were carried out in April-June 2003, and since then no infested crabs have been found. In summary, no S. neavei-infested crabs have been found anywhere in the focus since June 2003 and the vector is considered eliminated from that date. However, transmission had already been halted since February 2001. when the last biting flies had been collected. The parasite reservoir should die out in the human population by 2016. (C) 2009 Elsevier B.V. All rights reserved.