Prevalence and intensity of Onchocerca volvulus infection and efficacy of ivermectin in endemic communities in Ghana:: a two-phase epidemiological study
Prevalence and intensity of Onchocerca volvulus infection and efficacy of ivermectin in endemic communities in Ghana:: a two-phase epidemiological study
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DOI：
10.1016/s0140-6736(07)60942-8
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发表时间：
2007-06-16
期刊：
影响因子：
168.9
通讯作者：
Prichard, Roger K.
中科院分区：
文献类型：
--
作者：
Osei-Atweneboano, Mike Y.;Eng, Jeffrey K. L.;Prichard, Roger K.
背景：自1987年以来，伊维菌素一直用于控制盘尾丝虫病。由于这种药物的长期使用和其他线虫的耐药性的发展，我们评估了盘尾丝虫的负担、伊维菌素作为微丝杀虫剂的有效性及其对成年雌虫繁殖的影响。方法在研究的第一阶段，来自加纳19个每年接受6至18轮伊维菌素治疗的流行社区和1个伊维菌素初治社区的2501人，在2004年伊维菌素治疗前7天和治疗后30天，通过皮肤剪法评估伊维菌素的微丝虫载量，以评估伊维菌素的微丝虫杀灭作用。在第二阶段，在治疗后第90天和180天，从10个社区的342只微丝虫预处理评估阳性的个体中采集皮肤剪报，以确定伊维菌素对雌虫繁殖的影响，通过微丝虫的繁殖来评估。结果2501名受试者中微丝虫阳性487例（19%）。处理后群落微丝蚴流行率和群落微丝蚴载量分别为2.2% ~ 51.8%和0.06 ~ 2.85微丝蚴/条。尽管进行了治疗，2000年至2005年期间，两个社区的患病率翻了一番。伊维菌素治疗后30天的微丝虫评估显示，99%以上的人100%清除了微丝虫。处理后第90天，10个群落中有4个群落微丝虫量显著增加，从处理前的7.1%增加到21.1%，到第180天增加到53.9%。伊维菌素仍然是一种有效的微丝虫药。然而，我们的研究结果表明，对伊维菌素没有预期反应的耐药成年寄生虫种群正在出现。带有微丝虫病的皮肤的高繁殖率将允许寄生虫传播，可能与伊维菌素耐药的0扭转，这可能最终导致疾病复发。
Background Ivermectin has been used for onchocerciasis control since 1987. Because of the long-term use of this drug and the development of resistance in other nematodes, we have assessed Onchocerca volvulus burdens, effectiveness of ivermectin as a microfilaricide, and its effect on adult female worm reproduction.Methods For the first phase of the study, 2501 individuals in Ghana, from 19 endemic communities who had received six to 18 annual rounds of ivermectin and one ivermectin naive community, were assessed for microfilarial loads 7 days before the 2004 yearly ivermectin treatment, by means of skin snips, and 30 days after treatment to assess the ivermectin microfilaricidal action. For the second phase, skin snips were taken from 342 individuals from ten communities, who were microfilaria positive at pretreatment assessment, on days 90 and 180 after treatment, to identify the effects of ivermectin on female worm fertility, assessed by microfilaria repopulation.Findings 487 (19%) of the 2501 participants were microfilaria positive. The microfilaria prevalence and community microfilarial load in treated communities ranged from 2.2% to 51.8%, and 0.06 microfilariae per snip to 2.85 microfilariae per snip, respectively. Despite treatment, the prevalence rate doubled between 2000 and 2005 in two communities. Microfilaria assessment 30 days after ivermectin treatment showed 100% clearance of microfilaria in more than 99% of people. At day 90 after treatment, four of ten communities had significant microfilaria repopulation, from 7.1% to 21.1% of pretreatment counts, rising to 53.9% by day 180.Interpretation Ivermectin remains a potent microfilaricide. However, our results suggest that resistant adult parasite populations, which are not responding as expected to ivermectin, are emerging. A high rate of repopulation of skin with microfilariae will allow parasite transmission, possibly with ivermectin-resistant 0 volvulus, which could eventually lead to recrudescence of the disease.