Arm-in-cage testing of natural human-derived mosquito repellents

Malaria Journal

Research

Joshua Kemei¹  Nina M Stanczyk²  John A Pickett²  James G Logan³  Ahmed Hassanali⁴  Antônio EG Santana⁵  Karlos AL Ribeiro⁵  A Jennifer Mordue (Luntz)⁶ 

[1] Behavioural and Chemical Ecology Department, International Centre for Insect Physiology and Ecology, P.O. Box 30772, GPO 00100, Nairobi, Kenya;Biological Chemistry Department, Centre for Sustainable Pest and Disease Management, Rothamsted Research, AL5 2JQ, Harpenden, UK;Biological Chemistry Department, Centre for Sustainable Pest and Disease Management, Rothamsted Research, AL5 2JQ, Harpenden, UK;School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, AB24 2TZ, Aberdeen, UK;Chemistry Department, Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya;Behavioural and Chemical Ecology Department, International Centre for Insect Physiology and Ecology, P.O. Box 30772, GPO 00100, Nairobi, Kenya;Laboratório de Ecologia Química, Departamento de Química, Universidade Federal de Alagoas, 57072-970, Maceió, Alagoas, Brasil;School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, AB24 2TZ, Aberdeen, UK;

关键词: West Nile Virus;    Mosquito Species;    Protective Efficacy;    Deet;    Repellent Effect;   

DOI  :  10.1186/1475-2875-9-239

 received in 2010-05-11, accepted in 2010-08-20,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundIndividual human subjects are differentially attractive to mosquitoes and other biting insects. Previous investigations have demonstrated that this can be attributed partly to enhanced production of natural repellent chemicals by those individuals that attract few mosquitoes in the laboratory. The most important compounds in this respect include three aldehydes, octanal, nonanal and decanal, and two ketones, 6-methyl-5-hepten-2-one and geranylacetone [(E)-6,10-dimethylundeca-5,9-dien-2-one]. In olfactometer trials, these compounds interfered with attraction of mosquitoes to a host and consequently show promise as novel mosquito repellents.MethodsTo test whether these chemicals could provide protection against mosquitoes, laboratory repellency trials were carried out to test the chemicals individually at different concentrations and in different mixtures and ratios with three major disease vectors: Anopheles gambiae, Culex quinquefasciatus and Aedes aegypti.ResultsUp to 100% repellency was achieved depending on the type of repellent compound tested, the concentration and the relative composition of the mixture. The greatest effect was observed by mixing together two compounds, 6-methyl-5-hepten-2-one and geranylacetone in a 1:1 ratio. This mixture exceeded the repellency of DEET when presented at low concentrations. The repellent effect of this mixture was maintained over several hours. Altering the ratio of these compounds significantly affected the behavioural response of the mosquitoes, providing evidence for the ability of mosquitoes to detect and respond to specific mixtures and ratios of natural repellent compounds that are associated with host location.ConclusionThe optimum mixture of 6-methyl-5-hepten-2-one and geranylacetone was a 1:1 ratio and this provided the most effective protection against all species of mosquito tested. With further improvements in formulation, selected blends of these compounds have the potential to be exploited and developed as human-derived novel repellents for personal protection.

【 授权许可】

CC BY   
© Logan et al; licensee BioMed Central Ltd. 2010