Mukabana Wolfgang R, Takken Willem, Killeen Gerry F, Knols Bart GJ
Department of Zoology, University of Nairobi, PO Box 30197, Nairobi, Kenya.
Malar J. 2004 Jan 29;3(1):1. doi: 10.1186/1475-2875-3-1.
Removal of exhaled air from total body emanations or artificially standardising carbon dioxide (CO2) outputs has previously been shown to eliminate differential attractiveness of humans to certain blackfly (Simuliidae) and mosquito (Culicidae) species. Whether or not breath contributes to between-person differences in relative attractiveness to the highly anthropophilic malaria vector Anopheles gambiae sensu stricto remains unknown and was the focus of the present study. METHODS: The contribution to and possible interaction of breath (BR) and body odours (BO) in the attraction of An. gambiae s.s. to humans was investigated by conducting dual choice tests using a recently developed olfactometer. Either one or two human subjects were used as bait. The single person experiments compared the attractiveness of a person's BR versus that person's BO or a control (empty tent with no odour). His BO and total emanations (TE = BR+BO) were also compared with a control. The two-person experiments compared the relative attractiveness of their TE, BO or BR, and the TE of each person against the BO of the other. RESULTS: Experiments with one human subject (P1) as bait found that his BO and TE collected more mosquitoes than the control (P = 0.005 and P < 0.001, respectively), as did his BO and the control versus his BR (P < 0.001 and P = 0.034, respectively). The TE of P1 attracted more mosquitoes than that of another person designated P8 (P < 0.021), whereas the BR of P8 attracted more mosquitoes than the BR of P1 (P = 0.001). The attractiveness of the BO of P1 versus the BO of P8 did not differ (P = 0.346). The BO from either individual was consistently more attractive than the TE from the other (P < 0.001). CONCLUSIONS: We demonstrated for the first time that human breath, although known to contain semiochemicals that elicit behavioural and/or electrophysiological responses (CO2, ammonia, fatty acids) in An. gambiae also contains one or more constituents with allomonal (~repellent) properties, which inhibit attraction and may serve as an important contributor to between-person differences in the relative attractiveness of humans to this important malaria vector.
先前的研究表明，去除人体全身散发物中的呼出空气或人工标准化二氧化碳（CO₂）排放量，可消除人类对某些蚋（蚋科）和蚊子（蚊科）物种的不同吸引力。呼出的气息是否会导致人与人之间对嗜人疟蚊冈比亚按蚊（学名：Anopheles gambiae sensu stricto）的相对吸引力存在差异，目前尚不清楚，这也是本研究的重点。
使用最近开发的嗅觉计进行双选测试，研究呼出气息（BR）和体臭（BO）对冈比亚按蚊吸引人类的作用及其可能的相互作用。以一名或两名人类受试者作为诱饵。单人实验比较了一个人的呼出气息与该人的体臭或对照物（无气味的空帐篷）的吸引力。还将他的体臭和全身散发物（TE = BR + BO）与对照物进行了比较。两人实验比较了他们的全身散发物、体臭或呼出气息的相对吸引力，以及每个人的全身散发物相对于另一个人的体臭的吸引力。
以一名人类受试者（P1）作为诱饵的实验发现，他的体臭和全身散发物吸引的蚊子比对照物更多（分别为P = 0.005和P < 0.001），他的体臭与对照物相比其呼出气息吸引的蚊子也更多（分别为P < 0.001和P = 0.034）。P1的全身散发物吸引的蚊子比另一名指定为P8的人更多（P < 0.021），而P8的呼出气息吸引的蚊子比P1更多（P = 0.001）。P1的体臭与P8的体臭的吸引力没有差异（P = 0.346）。任何一个人的体臭始终比另一个人的全身散发物更具吸引力（P < 0.001）。
我们首次证明，人类呼出的气息虽然已知含有能引起冈比亚按蚊行为和/或电生理反应的信息素（CO₂、氨、脂肪酸），但也含有一种或多种具有异种信息素（类似驱避剂）特性的成分，这些成分会抑制吸引力，可能是导致人与人之间对这种重要疟疾媒介的相对吸引力存在差异的重要因素。
