Malaria incidence and entomological findings in an area targeted for a cluster-randomized controlled trial to prevent malaria in Ethiopia: results from a pilot study.
Malaria incidence and entomological findings in an area targeted for a cluster-randomized controlled trial to prevent malaria in Ethiopia: results from a pilot study.
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疟疾发生率和昆虫学发现，该区域是针对集群随机对照试验的，以防止埃塞俄比亚的疟疾：一项试点研究的结果。
DOI：
10.1186/s12936-016-1199-4
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发表时间：
2016-03-08
期刊：
影响因子：
3
通讯作者：
Lindtjørn B
中科院分区：
文献类型：
--
作者：
Gari T;Kenea O;Loha E;Deressa W;Hailu A;Balkew M;Gebre-Michael T;Robberstad B;Overgaard HJ;Lindtjørn B
这项研究是准备进行一项分组随机对照试验的工作的一部分，以评价室内滞留喷洒和长效驱虫蚊帐相结合对疟疾发病率的影响。进行了一项试点研究，结合昆虫标本收集和疟疾病媒对杀虫剂敏感性的评估，估计村庄之间疟疾发病率的变化。2013年8月至12月，在埃塞俄比亚中南部的996个家庭中，来自4个kebeles（最低的政府行政单位）的5309名居民被跟踪。通过手指针刺采集血样，用于疟疾感染的显微镜检查。应用多水平混合效应模型对疟疾发病的预测因子进行了分析。使用设置在室内靠近睡觉的人的灯光诱捕器、除虫菊喷雾片捕捉器和人工室外坑庇护所收集成蚊。酶联免疫吸附试验用于检测蚊子血餐的来源，而蚊子寿命估计的基础上胎次。世界卫生组织的试管生物测定试验被用来评估疟疾病媒对拟除虫菊酯和氨基甲酸酯的杀虫剂敏感性状况。疟疾发病率平均为每10 000人周观察4.6例。5 - 14岁年龄组（IRR = 2.7; 95%CI 1.1-6.6）和靠近湖泊或河流的小城镇（IRR = 14.2; 95%CI 3.1-64）与疟疾发病显著相关。只有271户（27.3%）拥有驱虫蚊帐。在采集的232只成蚊中，阿拉伯按蚊为优势种，占71.1%.安的平均寿命。arabiensis为14天（范围：7-25人血液指数天）。An的总体人体血液指数（0.69）。阿拉伯山羊血液指数高于牛血液指数（0.38）。在kebeles之间观察到按蚊丰度的统计学显著差异（P = 0.001）。阿拉伯按蚊对残杀威敏感，对拟除虫菊酯耐药。然而，安。pharoensis对所有测试的拟除虫菊酯和氨基甲酸酯敏感。这项研究表明，在kebeles之间，疟疾发病率和按蚊的变化很大。观察到的疟疾病媒对残杀威的敏感性证明了使用这种杀虫剂进行室内滞留喷洒的必要性，这项研究的结果将用作试验的基线。
This study was part of the work to prepare for a cluster-randomized controlled trial to evaluate the effect of combining indoor residual spraying and long-lasting insecticidal nets on malaria incidence. A pilot study was done to estimate the variations of malaria incidence among villages, combined with entomological collections and an assessment of susceptibility to insecticides in malaria vectors. A cohort of 5309 residents from four kebeles (the lowest government administrative unit) in 996 households was followed from August to December 2013 in south-central Ethiopia. Blood samples were collected by a finger prick for a microscopic examination of malaria infections. A multilevel mixed effect model was applied to measure the predictors of malaria episode. Adult mosquitoes were collected using light traps set indoors close to a sleeping person, pyrethrum spray sheet catches and artificial outdoor pit shelters. Enzyme-linked immunosorbent assays were used to detect the sources of mosquito blood meals, while mosquito longevity was estimated based on parity. The World Health Organization’s tube bioassay test was used to assess the insecticide susceptibility status of malaria vectors to pyrethroids and carbamates. The average incidence of malaria episode was 4.6 per 10,000 person weeks of observation. The age group from 5 to 14 years (IRR = 2.7; 95 % CI 1.1–6.6) and kebeles near a lake or river (IRR = 14.2, 95 % CI 3.1–64) were significantly associated with malaria episode. Only 271 (27.3 %) of the households owned insecticide-treated nets. Of 232 adult Anopheles mosquitoes collected, Anopheles arabiensis (71.1 %) was the predominant species. The average longevity of An. arabiensis was 14 days (range: 7–25 human blood index days). The overall human blood index (0.69) for An. arabiensis was higher than the bovine blood index (0.38). Statistically significant differences in Anopheline mosquitoes abundance were observed between the kebeles (P = 0.001). Anopheles arabiensis was susceptible to propoxur, but resistant to pyrethroids. However, An. pharoensis was susceptible to all pyrethroids and carbamates tested. This study showed a high variation in malaria incidence and Anopheles between kebeles. The observed susceptibility of the malaria vectors to propoxur warrants using this insecticide for indoor residual spraying, and the results from this study will be used as a baseline for the trial.