Effects of larval exposure to sublethal doses of ivermectin on adult fitness and susceptibility to ivermectin in Anopheles gambiae s.s.

Parasites & Vectors

Research

Caroline Kiuru¹  Carlos Chaccour²  Lawrence Babu³  Caroline Wanjiku³  Martha Muturi³  Marta Ferreira Maia⁴  Kelly Ominde⁵ 

[1] Barcelona Institute for Global Health (ISGlobal), Hospital Clínic - Universitat de Barcelona, Rosello 132, 5ª 2ª, 08036, Barcelona, Spain;Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique;Barcelona Institute for Global Health (ISGlobal), Hospital Clínic - Universitat de Barcelona, Rosello 132, 5ª 2ª, 08036, Barcelona, Spain;Facultad de Medicina, Universidad de Navarra, 31008, Pamplona, Spain;Centro de Investigación Biomédica en Red de Enfermedades Infecciosas, Madrid, Spain;Department of Biosciences, KEMRI Wellcome Trust Research Programme (KWTRP), 230-80108, Kilifi, Kenya;Department of Biosciences, KEMRI Wellcome Trust Research Programme (KWTRP), 230-80108, Kilifi, Kenya;Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK;Department of Biosciences, KEMRI Wellcome Trust Research Programme (KWTRP), 230-80108, Kilifi, Kenya;Pwani University, Department of Biological Sciences and Pwani University Bioscience Research Centre (PUBReC), Kilifi, Kenya;

关键词: Ivermectin;    Mosquito larvae;    Adult fitness;    Anopheles gambiae;   

DOI  :  10.1186/s13071-023-05888-w

 received in 2023-03-01, accepted in 2023-07-18,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundThe effects of ivermectin (endectocide) on mosquito survival make it a potential new malaria vector control tool. The drug can be administered to mosquito disease vectors through blood hosts that include humans and livestock. Its increased use may cause contamination of larval habitats, either directly through livestock excreta or indirectly through leaching or run-off from contaminated soil, albeit in sublethal doses. However, the effects of such exposure on immature stages and the subsequent adults that emerge are poorly understood. This study was undertaken to evaluate the impact of ivermectin exposure on Anopheles gambiae s.s. larvae and its effects on fitness and susceptibility to ivermectin in the emerging adults.MethodsLaboratory-reared An. gambiae s.s. (Kilifi strain) larvae were exposed to five different ivermectin concentrations; 0, 0.00001, 0.0001, 0.001, and 0.01 ppm, and larval survival was monitored to determine the appropriate sub-lethal dose. Concentrations with survival > 50% (0.00001 and 0.0001 ppm) were selected and used as the sub-lethal doses. The fecundity, fertility, and susceptibility to ivermectin of adults emerging after larval exposure to the sub-lethal doses were examined.ResultsOverall, exposure of An. gambiae s.s. aquatic stages to ivermectin caused a dose-dependent reduction in larval survival irrespective of the stage at which the larvae were exposed. Exposure to ivermectin in the larval stage did not have an effect on either the number of eggs laid or the hatch rate. However, exposure of first/second-instar larvae to 0.0001 ppm and third/fourth-instar larvae to 0.001 ppm of ivermectin reduced the time taken to oviposition. Additionally, exposure to ivermectin in the larval stage did not affect susceptibility of the emerging adults to the drug.ConclusionsThis study shows that contamination of larval habitats with ivermectin affects An. gambiae s.s. larval survival and could potentially have an impact on public health. However, there are no carry-over effects on the fecundity, fertility, and susceptibility of the emerging adults to ivermectin. In addition, this study shows that environmental exposure to ivermectin in the larval habitats is unlikely to compromise the efficacy of ivermectin in the emerging adults.Graphical Abstract

【 授权许可】

CC BY   
© BioMed Central Ltd., part of Springer Nature 2023

【 图 表 】

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