Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of the Congo.
PLoS Negl Trop Dis. 2020 Oct 16;14(10):e0008270. doi: 10.1371/journal.pntd.0008270. eCollection 2020 Oct.
Over the past 20 years there has been a >95% reduction in the number of Gambian Human African trypanosomiasis (g-HAT) cases reported globally, largely as a result of large-scale active screening and treatment programmes. There are however still foci where the disease persists, particularly in parts of the Democratic Republic of the Congo (DRC). Additional control efforts such as tsetse control using Tiny Targets may therefore be required to achieve g-HAT elimination goals. The purpose of this study was to evaluate the impact of Tiny Targets within DRC. In 2015-2017, pre- and post-intervention tsetse abundance data were collected from 1,234 locations across three neighbouring Health Zones (Yasa Bonga, Mosango, Masi Manimba). Remotely sensed dry season data were combined with pre-intervention tsetse presence/absence data from 332 locations within a species distribution modelling framework to produce a habitat suitability map. The impact of Tiny Targets on the tsetse population was then evaluated by fitting a generalised linear mixed model to the relative fly abundance data collected from 889 post-intervention monitoring sites within Yasa Bonga, with habitat suitability, proximity to the intervention and intervention duration as covariates. Immediately following the introduction of the intervention, we observe a dramatic reduction in fly catches by > 85% (pre-intervention: 0.78 flies/trap/day, 95% CI 0.676-0.900; 3 month post-intervention: 0.11 flies/trap/day, 95% CI 0.070-0.153) which is sustained throughout the study period. Declines in catches were negatively associated with proximity to Tiny Targets, and while habitat suitability is positively associated with abundance its influence is reduced in the presence of the intervention. This study adds to the body of evidence demonstrating the impact of Tiny Targets on tsetse across a range of ecological settings, and further characterises the factors which modify its impact. The habitat suitability maps have the potential to guide the expansion of tsetse control activities in this area.
在过去的 20 年中，全球报告的冈比亚人类非洲锥虫病（g-HAT）病例数量减少了>95%，这主要是由于大规模的主动筛查和治疗计划。然而，疾病仍然存在一些焦点，特别是在刚果民主共和国（DRC）的部分地区。因此，可能需要使用 Tiny Targets 等采采蝇控制等额外的控制措施来实现 g-HAT 消除目标。本研究旨在评估 Tiny Targets 在 DRC 的影响。2015-2017 年，在三个邻近卫生区（Yasa Bonga、Mosango、Masi Manimba）的 1234 个地点收集了干预前后采采蝇丰度数据。将遥感旱季数据与 332 个地点的干预前采采蝇存在/不存在数据结合在物种分布建模框架中，生成了一个栖息地适宜性图。然后，通过拟合广义线性混合模型，将从 Yasa Bonga 内 889 个干预后监测点收集的相对苍蝇丰度数据评估 Tiny Targets 对采采蝇种群的影响，将栖息地适宜性、与干预的接近程度和干预持续时间作为协变量。在干预措施实施后不久，我们观察到苍蝇捕获量急剧减少了>85%（干预前：0.78 只/陷阱/天，95%CI 0.676-0.900；3 个月后干预：0.11 只/陷阱/天，95%CI 0.070-0.153），这一趋势在整个研究期间持续。捕获量的下降与靠近 Tiny Targets 呈负相关，尽管栖息地适宜性与丰度呈正相关，但在存在干预的情况下，其影响会降低。本研究增加了证据表明 Tiny Targets 在一系列生态环境中对采采蝇的影响，并进一步描述了影响其影响的因素。栖息地适宜性图有可能指导该地区采采蝇控制活动的扩展。
