Evaluating putative repellent ‘push’ and attractive ‘pull’ components for manipulating the odour orientation of host-seeking malaria vectors in the peri-domestic space

Parasites & Vectors

Sarah Moore¹  Adam Saddler¹  Ulrike Fillinger²  Margaret Mendi Njoroge³  Alexandra Hiscox⁴  Joop J. A. van Loon⁵  Willem Takken⁵ 

[1] Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 833, Basel, Switzerland;University of Basel, Petersplatz 1, Basel, Switzerland;Department of Environmental Health and Ecological Sciences, Ifakara Health Institute, P.O. Box 74, Bagamoyo, Tanzania;International Centre of Insect Physiology and Ecology (icipe), Human Health Theme, 00100, Nairobi, Kenya;International Centre of Insect Physiology and Ecology (icipe), Human Health Theme, 00100, Nairobi, Kenya;Laboratory of Entomology, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands;International Centre of Insect Physiology and Ecology (icipe), Human Health Theme, 00100, Nairobi, Kenya;Laboratory of Entomology, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands;London School of Hygiene and Tropical Medicine, ARCTEC, Keppel Street, WC1E 7HT, London, UK;Laboratory of Entomology, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands;

关键词: Malaria;    Vector control;    Outdoor-biting;    Spatial repellent;    PMD;    Citriodiol;    Transfluthrin;    GC-FID;    Semi-field study;   

DOI  :  10.1186/s13071-020-04556-7

来源: Springer

【 摘 要 】

BackgroundNovel malaria vector control approaches aim to combine tools for maximum protection. This study aimed to evaluate novel and re-evaluate existing putative repellent ‘push’ and attractive ‘pull’ components for manipulating the odour orientation of malaria vectors in the peri-domestic space.MethodsAnopheles arabiensis outdoor human landing catches and trap comparisons were implemented in large semi-field systems to (i) test the efficacy of Citriodiol® or transfluthrin-treated fabric strips positioned in house eave gaps as push components for preventing bites; (ii) understand the efficacy of MB5-baited Suna-traps in attracting vectors in the presence of a human being; (iii) assess 2-butanone as a CO2 replacement for trapping; (iv) determine the protection provided by a full push-pull set up. The air concentrations of the chemical constituents of the push–pull set-up were quantified.ResultsMicroencapsulated Citriodiol® eave strips did not provide outdoor protection against host-seeking An. arabiensis. Transfluthrin-treated strips reduced the odds of a mosquito landing on the human volunteer (OR 0.17; 95% CI 0.12–0.23). This impact was lower (OR 0.59; 95% CI 0.52–0.66) during the push-pull experiment, which was associated with low nighttime temperatures likely affecting the transfluthrin vaporisation. The MB5-baited Suna trap supplemented with CO2 attracted only a third of the released mosquitoes in the absence of a human being; however, with a human volunteer in the same system, the trap caught < 1% of all released mosquitoes. The volunteer consistently attracted over two-thirds of all mosquitoes released. This was the case in the absence (‘pull’ only) and in the presence of a spatial repellent (‘push-pull’), indicating that in its current configuration the tested ‘pull’ does not provide a valuable addition to a spatial repellent. The chemical 2-butanone was ineffective in replacing CO2. Transfluthrin was detectable in the air space but with a strong linear reduction in concentrations over 5 m from release. The MB5 constituent chemicals were only irregularly detected, potentially suggesting insufficient release and concentration in the air for attraction.ConclusionThis step-by-step evaluation of the selected ‘push’ and ‘pull’ components led to a better understanding of their ability to affect host-seeking behaviours of the malaria vector An. arabiensis in the peri-domestic space and helps to gauge the impact such tools would have when used in the field for monitoring or control.

【 授权许可】

CC BY