Identifying the effective concentration for spatial repellency of the dengue vector Aedes aegypti

Particle and Fibre Toxicology

John Grieco⁵  Joko Hendarto³  Suppaluck Polsomboon⁵  Theeraphap Chareonviryiphap¹  Nicholas Martin⁴  Philip Smith²  Penny Masuoka⁵  Nicole Achee⁵ 

[1] Department of Entomology, Faculty of Agriculture, Katsetsart University, Bangkok, 10900, Thailand;Department of Labor-Occupational Health and Safety Administration, Health Response Team, 8660 South Sandy Pkwy, Sandy, UT, USA;Department of Public Health and Preventive Medicine, Faculty of Medicine, Hasanuddin University, Makassar, 90245, Indonesia;Department, Infectious Diseases Directorate, Viral and Rickettsial Diseases, U. S. Naval Medical Research Center, 503 Robert Grant Ave, Silver Spring, MD, USA;Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd, Bethesda, MD, USA

关键词: Metofluthrin;    DDT;    Chemical concentration;    Experimental hut;    Mosquito behavior;    Aedes aegypti;    Air sampling;    Spatial repellency;   

Others  :  1228105
DOI  :  10.1186/1756-3305-5-300

 received in 2012-09-28, accepted in 2012-12-22,  发布年份 2012

【 摘 要 】

Background

Current efforts are underway to quantify the chemical concentration in a treated air space that elicits a spatial repellent (deterrent) response in a vector population. Such information will facilitate identifying the optimum active ingredient (AI) dosage and intervention coverage important for the development of spatial repellent tools – one of several novel strategies being evaluated for vector-borne disease control. This study reports initial findings from air sampling experiments conducted under field conditions to describe the relationship between air concentrations of repellent AIs and deterrent behavior in the dengue vector, Aedes aegypti.

Methods

Air samples were taken inside and outdoors of experimental huts located in Pu Tuey Village, Kanchanaburi Province, Thailand in conjunction with mosquito behavioral evaluations. A mark-release-recapture study design using interception traps was used to measure deterrency of Ae. aegypti against 0.00625% metofluthrin coils and DDT-treated fabric (2g/m²) within separate experimental trials. Sentinel mosquito cohorts were positioned adjacent to air sampling locations to monitor knock down responses to AI within the treated air space. Air samples were analyzed using two techniques: the U.S. Environmental Protection Agency (USEPA) Compendium Method TO-10A and thermal desorption (TD).

Results

Both the USEPA TO-10A and TD air sampling methods were able to detect and quantify volatized AIs under field conditions. Air samples indicated concentrations of both repellent chemicals below thresholds required for toxic responses (mortality) in mosquitoes. These concentrations elicited up to a 58% and 70% reduction in Ae. aegypti entry (i.e., deterrency) into treated experimental huts using metofluthrin coils and DDT-treated fabric, respectively. Minimal knock down was observed in sentinel mosquito cohorts positioned adjacent to air sampling locations during both chemical evaluations.

Conclusions

This study is the first to describe two air sampling methodologies that are appropriate for detecting and quantifying repellent chemicals within a treated air space during mosquito behavior evaluations. Results demonstrate that the quantity of AI detected by the mosquito vector, Ae. aegypti, that elicits repellency is far lower than that needed for toxicity. These findings have important implications for evaluation and optimization of new vector control tools that function through mosquito behavior modification as opposed to mortality.

【 授权许可】

   
2012 Achee et al.; licensee BioMed Central Ltd.

【 图 表 】

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【 参考文献 】

• [1]Alonso PL, Brown G, Arevalo-Herrera M, Binka F, Chitnis C, et al.: A Research Agenda to Underpin Malaria Eradication. PLoS Med 2010, 8(1):e1000406.
• [2]Achee NL, Bangs MJ, Farlow R, Killeen GF, Lindsay S, Logan JG, Moore SJ, Rowland M, Sweeney K, Torr SJ, Zwiebel L, Grieco JP: Spatial repellents: from discovery and development to evidence-based validation. Malar J 2012, 11(1):164. BioMed Central Full Text
• [3]Grieco JP, Achee NL, Chareonviriyaphap T, Suwonkerd W, Chauhan K, Sardelis MR, Roberts DR: A new classification system for the actions of IRS chemicals traditionally used for malaria control. PLoS One 2007, 2(8):e716.
• [4]Reinert JF, Harbach RE, Kitching IJ: Phylogeny and classification of tribe Aedini (Diptera: Culicidae). Zool J Linnean Soc 2009, 157:700-794.
• [5]WHO [World Health Organization]: WHO recommended insecticides for indoor residual spraying against malaria vectors. Geneva, Switzerland: World Health Organization; 2009. http://apps.who.int/malaria/cmc_upload/0/000/012/604/IRS/Insecticides.htm webcite. Accessed 2009 September 2
• [6]Chareonviriyaphap T, Grieco JP, Suwonkerd W, Prabaripai A, Polsomboon S, et al.: An improved experimental hut design for the study of Aedes aegypti (Diptera: Culicidae) movement patterns in Thailand. J Vector Ecol 2010, 35:428-431.
• [7]U.S. Environmental Protection Agency: Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air. 2nd edition. 1999. EPA/625/R-96/010b
• [8]Ogoma SB, Moore SJ, Maia MF: A systematic review of mosquito coils and passive emanators: defining recommendations for spatial repellency testing methodologies. Parasites Vectors 2012, 5:287. BioMed Central Full Text
• [9]Martin NJ, Smith PA, Brown CW, Achee NL, Delong GT: Dichlorodiphenyltrichloroethane determination in air by thermal desorption gas chromatography–mass spectrometry. Pest Manag Sci 2012.
• [10]Clement M, Arzel S, Le Bot B, Seux R, Millet M: Adsorption/thermal desorption-GC/MS for the analysis of pesticides in the atmosphere. Chemosphere 2000, 40:49-56.
• [11]Thanispong K, Sathantriphop S, Chareonviriyaphap T: Insecticide resistance of Aedes aegypti and Culex quinquefasciatus in Thailand. J Pestic Sci 2008, 33:351-356.
• [12]Suwannachote N, Grieco JP, Achee NL, Suwonkerd W, Wongtong S, Chareonviriyaphap T: Effect of environmental conditions on the movement patterns of Aedes aegypti (Diptera: Culicidae) into and out of experimental huts in Thailand. J Vector Ecol 2009, 34:267-275.
• [13]WHO [World Health Organization]: Guidelines for efficacy testing of insecticides for indoor and outdoor ground-applied space spray applications. WHO/CDS/NTD/WHOPES/2009.2
• [14]Ditzen M, Pellegrino M, Vosshall LB: Insect odorant receptors are molecular targets of the insect repellent DEET. Science 2008, 319:1838-1842.