Talbot Benoit, Alou Ludovic P Ahoua, Koffi Alphonsine A, Sih Colette, Dangbenon Edouard, Zoh Marius G, Camara Soromane, Assi Serge B, N'Guessan Raphael, Messenger Louisa A, Protopopoff Natacha, Cook Jackie, Kulkarni Manisha A
School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada.
Institut Pierre Richet (IPR)/Institut National de Santé Publique (INSP), Bouaké, Côte d'Ivoire.
Parasit Vectors. 2025 Aug 12;18(1):343. doi: 10.1186/s13071-025-06984-9.
Malaria is a mosquito-borne parasitic disease that causes significant morbidity and mortality in at-risk populations, especially in children in sub-Saharan Africa. Despite reductions in malaria burden owing to the scale-up of effective interventions, there are concerns that long-lasting insecticidal net (LLIN) effects may not be sustained owing to widespread insecticide resistance and differential impacts of LLIN on vector species. In this study, we aimed to test the effect of different LLIN products and other environmental factors on the ecological niche of three mosquito vector species using state-of-the-art ecological niche modelling approaches.
This study used data from a cluster randomized control trial that took place in Tiébissou, in Central Côte d'Ivoire. Anopheles mosquito density and Plasmodium falciparum vector infection data were available across 33 clusters. We used satellite remote sensing related to land cover, climate, topography and population density across the study area alongside vector species occurrence data to construct ecological niche models for An. coluzzi, An. gambiae s.s. and An. funestus s.s., and for P. falciparum-infected vectors, at baseline and 1-year post-LLIN intervention. We compared the projected habitat and habitat determinants for each species, and assessed the respective contributions of each intervention arm and environmental factors on the probability of species occurrence.
Minimal to considerable overall reductions in suitable habitat across the study area were observed for the three mosquito vector species (less than 1% to more than 60%), and considerable overall reduction was observed for P. falciparum-infected vectors (more than 50%). We did not detect an effect of intervention arm on the probability of occurrence of any vector species, while we found strong significant effects of a combination of land cover, climate, topography and/or population density variables on each of the three mosquito vector species and malaria-infected vectors. Our results suggest environmental factors may have facilitated or restricted changes in the probability of occurrence of vector species and infected vectors in the context of vector control interventions.
Our study highlights wide ecological differences across malaria vector species and supports the need to consider malaria vector species composition when deploying malaria vector control interventions in endemic settings.
疟疾是一种由蚊子传播的寄生虫病，在高危人群中导致严重的发病和死亡，尤其是撒哈拉以南非洲的儿童。尽管由于扩大有效干预措施，疟疾负担有所减轻，但人们担心，由于广泛的杀虫剂抗性以及长效驱虫蚊帐（LLIN）对病媒种类的不同影响，LLIN的效果可能无法持续。在本研究中，我们旨在使用最先进的生态位建模方法，测试不同LLIN产品和其他环境因素对三种蚊虫病媒种类生态位的影响。
本研究使用了在科特迪瓦中部的蒂比苏进行的一项整群随机对照试验的数据。在33个整群中可获得按蚊密度和恶性疟原虫病媒感染数据。我们使用与研究区域的土地覆盖、气候、地形和人口密度相关的卫星遥感数据以及病媒种类出现数据，为科氏按蚊、冈比亚按蚊指名亚种和富氏按蚊指名亚种以及感染恶性疟原虫的病媒构建基线和LLIN干预1年后的生态位模型。我们比较了每个物种的预测栖息地和栖息地决定因素，并评估了每个干预组和环境因素对物种出现概率的各自贡献。
观察到三种蚊虫病媒种类在整个研究区域的适宜栖息地总体减少幅度从极小到相当大（不到1%至超过60%），并且观察到感染恶性疟原虫的病媒总体减少幅度相当大（超过50%）。我们未检测到干预组对任何病媒种类出现概率的影响，而我们发现土地覆盖、气候、地形和/或人口密度变量的组合对三种蚊虫病媒种类和感染疟疾的病媒均有强烈的显著影响。我们的结果表明，在病媒控制干预的背景下，环境因素可能促进或限制了病媒种类和感染病媒出现概率的变化。
我们的研究突出了疟疾病媒种类之间广泛的生态差异，并支持在流行地区部署疟疾病媒控制干预措施时需要考虑疟疾病媒种类组成。
