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Attraction of Anopheles gambiae to odour baits augmented with heat and moisture

BACKGROUND: The search for a standard human surrogate in the form of a synthetic mosquito attractant has been the goal of many laboratories around the world. Besides alleviating the occupational risk subjected to volunteers participating in vector surveillance and control, discovery of potent attrac...

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Autores principales: Olanga, Evelyn A, Okal, Michael N, Mbadi, Phoebe A, Kokwaro, Elizabeth D, Mukabana, Wolfgang R
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2822790/
https://www.ncbi.nlm.nih.gov/pubmed/20051143
http://dx.doi.org/10.1186/1475-2875-9-6
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author Olanga, Evelyn A
Okal, Michael N
Mbadi, Phoebe A
Kokwaro, Elizabeth D
Mukabana, Wolfgang R
author_facet Olanga, Evelyn A
Okal, Michael N
Mbadi, Phoebe A
Kokwaro, Elizabeth D
Mukabana, Wolfgang R
author_sort Olanga, Evelyn A
collection PubMed
description BACKGROUND: The search for a standard human surrogate in the form of a synthetic mosquito attractant has been the goal of many laboratories around the world. Besides alleviating the occupational risk subjected to volunteers participating in vector surveillance and control, discovery of potent attractants underpins the development and deployment of mass trapping devices for controlling mosquito-borne diseases. METHODS: A dual-port olfactometer was used to assess behavioural responses of female Anopheles gambiae mosquitoes towards synthetic versus natural (whole human emanations and worn socks) attractants. The synthetic attractants included a standard blend consisting of ammonia, carbon dioxide and water; and Ifakara blend 1 (IB1) consisting of various aliphatic carboxylic acids. Natural attractants were obtained from two males known to be less and highly attractive (LA and HA, respectively) to the mosquitoes. Mosquito responses to the volunteers' worn socks were also investigated. The effect of heat (25-27°C) and moisture (75-85%) on the mosquito behavioural responses was determined. RESULTS: A significantly higher proportion of mosquitoes was attracted to each volunteer when compared to the standard blend. Whereas the proportion of mosquitoes attracted to person LA versus IB1 (49% versus 51%, respectively; P = 0.417) or his worn socks did not differ (61% versus 39%, respectively; P = 0.163), far more mosquitoes were attracted to person HA relative to IB1 (96% versus 4%; P = 0.001) or his worn socks (91% versus 9%; P = 0.001). Person HA attracted a significantly higher proportion of mosquitoes than his worn socks, the standard blend and IB1 when these were augmented with heat, moisture or both (P = 0.001). Similar results were obtained with person LA except that the proportion of mosquitoes attracted to him versus his worn sock augmented with heat (P = 0.65) or IB1 augmented with heat and moisture (P = 0.416) did not differ significantly. CONCLUSIONS: These findings indicate that olfactory cues are key mediators of the mosquito host-seeking process and that heat and moisture play a minor role. The need for a standard, highly stringent positive control for screening synthetic attractants is strongly highlighted.
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spelling pubmed-28227902010-02-17 Attraction of Anopheles gambiae to odour baits augmented with heat and moisture Olanga, Evelyn A Okal, Michael N Mbadi, Phoebe A Kokwaro, Elizabeth D Mukabana, Wolfgang R Malar J Research BACKGROUND: The search for a standard human surrogate in the form of a synthetic mosquito attractant has been the goal of many laboratories around the world. Besides alleviating the occupational risk subjected to volunteers participating in vector surveillance and control, discovery of potent attractants underpins the development and deployment of mass trapping devices for controlling mosquito-borne diseases. METHODS: A dual-port olfactometer was used to assess behavioural responses of female Anopheles gambiae mosquitoes towards synthetic versus natural (whole human emanations and worn socks) attractants. The synthetic attractants included a standard blend consisting of ammonia, carbon dioxide and water; and Ifakara blend 1 (IB1) consisting of various aliphatic carboxylic acids. Natural attractants were obtained from two males known to be less and highly attractive (LA and HA, respectively) to the mosquitoes. Mosquito responses to the volunteers' worn socks were also investigated. The effect of heat (25-27°C) and moisture (75-85%) on the mosquito behavioural responses was determined. RESULTS: A significantly higher proportion of mosquitoes was attracted to each volunteer when compared to the standard blend. Whereas the proportion of mosquitoes attracted to person LA versus IB1 (49% versus 51%, respectively; P = 0.417) or his worn socks did not differ (61% versus 39%, respectively; P = 0.163), far more mosquitoes were attracted to person HA relative to IB1 (96% versus 4%; P = 0.001) or his worn socks (91% versus 9%; P = 0.001). Person HA attracted a significantly higher proportion of mosquitoes than his worn socks, the standard blend and IB1 when these were augmented with heat, moisture or both (P = 0.001). Similar results were obtained with person LA except that the proportion of mosquitoes attracted to him versus his worn sock augmented with heat (P = 0.65) or IB1 augmented with heat and moisture (P = 0.416) did not differ significantly. CONCLUSIONS: These findings indicate that olfactory cues are key mediators of the mosquito host-seeking process and that heat and moisture play a minor role. The need for a standard, highly stringent positive control for screening synthetic attractants is strongly highlighted. BioMed Central 2010-01-06 /pmc/articles/PMC2822790/ /pubmed/20051143 http://dx.doi.org/10.1186/1475-2875-9-6 Text en Copyright ©2010 Olanga et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Olanga, Evelyn A
Okal, Michael N
Mbadi, Phoebe A
Kokwaro, Elizabeth D
Mukabana, Wolfgang R
Attraction of Anopheles gambiae to odour baits augmented with heat and moisture
title Attraction of Anopheles gambiae to odour baits augmented with heat and moisture
title_full Attraction of Anopheles gambiae to odour baits augmented with heat and moisture
title_fullStr Attraction of Anopheles gambiae to odour baits augmented with heat and moisture
title_full_unstemmed Attraction of Anopheles gambiae to odour baits augmented with heat and moisture
title_short Attraction of Anopheles gambiae to odour baits augmented with heat and moisture
title_sort attraction of anopheles gambiae to odour baits augmented with heat and moisture
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2822790/
https://www.ncbi.nlm.nih.gov/pubmed/20051143
http://dx.doi.org/10.1186/1475-2875-9-6
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