生活研究:哪種人是蚊子的最愛?

It is peak mosquito season, and while some lucky outdoor venturers seem unperturbed by the tiny insects, others appear to be relentlessly assaulted. Scientists are trying to understand what makes certain humans more attractive to the bugs. One expert, molecular vector biologist L.J. Zwiebel, a professor of biological sciences at Vanderbilt University, weighs in.
眼下正是蚊子活動的高峯期，有些在室外活動的幸運兒好像並不受這種小小昆蟲的侵擾，而另一些人則似乎不斷遭到它們的侵襲。科學家們就什麼原因導致某些人更吸引這些惱人的東西進行了探索。其中一名專家──範德堡大學(Vanderbilt University)生物學教授、分子載體生物學家L.J.茨維伯爾(L. J. Zwiebel)也加入了討論。

Sweet Smell of Success
人體氣味 Mosquitoes find their mammalian prey through sensing the heat and carbon dioxide mammals emit. Pregnant women and larger people are sometimes the victim of multiple attacks, since they exert more energy than the average person.
蚊子通過感知哺乳動物釋放出的熱量和二氧化碳來尋找它們的“獵物”。有時候，懷孕女性與體型較大的人會遭到蚊子多次侵襲，因爲他們會比普通人散發出更多能量。

Mosquitoes are also guided by their sense of smell. 'Despite what my grandmother told me, I don't have sweet blood,' says Dr. Zwiebel, since mosquitoes cannot distinguish blood quality. 'Mosquitoes are attracted to our human odor, and that is largely a consequence of the bacteria on our skin,' says Dr. Zwiebel. The 'flora and fauna on our skin' also smell appetizing to mosquitoes, says Dr. Zweibel, and these can increase when we sweat or spend a lot of time outdoors.
此外，蚊子也受到它們嗅覺的指引。茨維伯爾說：“不管我奶奶以前對我講過什麼，但是我的血肯定不香甜，”這是因爲蚊子並不能辨別血液的品質。他指出：“蚊子是被我們人類的氣味吸引的，這主要是因爲我們皮膚上有細菌。”他說，“我們皮膚上菌羣”的氣味也吸引蚊子，當我們出汗或在室外呆了很長時間後，這些菌羣的數量就會增加。

As far as Dr. Zwiebel knows, there is no scientific basis to prove that having high cholesterol or diabetes, despite what some websites claim, will keep bugs away. Nor will taking vitamin B supplements, eating garlic or taking specific medications.
就茨維伯爾所知，儘管某些網站報道稱高膽固醇或糖尿病可防範蚊子，但這一說法並無科學證明。此外，服用維生素B、吃大蒜或服用某些藥物可驅蚊的說法也沒有科學依據。

Skeeter Immunity
叮咬免疫力 After 20 years in labs with the biting bugs, Dr. Zwiebel says he can stick his arm into a container of mozzies and be bit hundreds of times, yet 'not have a hair out of place.' Children, who have been bitten far fewer times than adults, may have stronger reactions to bites, since their immune systems haven't matured fully. But adults who are convinced they are being victimized by the bloodsuckers usually are not. 'There are some people who have strong allergic responses to the bites which may make it seem like they're being bit more often, but they're probably not,' Dr. Zwiebel notes.
茨維伯爾在實驗室中與這種咬人的昆蟲呆了20年時間，他說他能把胳膊伸進一個裝有蚊子的容器中，被咬上幾百次也“毫髮無損”。兒童被蚊子叮咬的頻率低於成年人，但他們對叮咬的反應可能會更強烈，因爲他們的免疫系統尚未完全成熟。常常有些確信自己被這種“吸血蟲”侵害的成年人其實並沒遭到叮咬。茨維伯爾指出：“有些人會對叮咬產生強烈的過敏反應，這可能會使他們顯得更經常遭受叮咬，但也許事情並非如此。”Fighting Back
人體的反擊
For people covered in welts and itchy wounds, Dr. Zwiebel says to stop scratching: When the mosquito bites, it leaves behind some of its saliva, a substance that contains anticoagulants and a local anesthetic, among other things. The body recognizes it as a foreign invader and sends histamines in to counterattack. Scratching just spreads the saliva and encourages the release of more antibodies, and more itching -- a vicious cycle.
對於出現紅腫和發癢傷口的人，茨維伯爾建議他們不要抓撓傷口。蚊子在叮人時會留下一些唾液及其他物質，其中它的唾液含有抗凝血劑和一種局部麻醉成分。人體會把唾液認作外來入侵物，釋放出組胺來予以反擊。抓撓傷口只會使唾液擴散，引發身體釋放出更多抗體，讓傷口變得更癢，由此引發惡性循環。
Those who swell up and itch a lot when bitten 'should speak with their doctor about taking an over-the-counter antihistamine daily as a precaution,' says Dr. Zwiebel. The bugs will still bite, but you may not notice, since the drug prevents the allergic response that turns a painless bite into an itchy nuisance.
茨維伯爾建議，那些遭蚊蟲叮咬後傷口腫脹或傷口非常癢的人，“應與醫生談談，看看是否需要每天服用一種非處方抗組胺劑用於預防”。服用該藥物後，蚊子仍會咬你，不過你可能就注意不到了，因爲它可預防過敏反應，從而避免無痛的叮咬發展爲惱人的癢痛。

Cleaner Is Meaner
清潔抗菌
Female mosquitoes are driven to bite you as they need a blood meal to complete their reproductive cycle and produce fertile eggs, which takes a huge boost of protein. To reduce the chances of being bitten, wash with an antibacterial soap to reduce the volume of mosquito-attracting bacteria on your skin.
在需要吸血以完成它們的繁殖週期、產下幼卵（這需要大量補充蛋白質）時，雌蚊子便會去咬人。若要降低被蚊子叮咬的機率，可用抗菌香皂清洗身體以減少皮膚表面吸引蚊子的細菌的數量。
Other ways to dodge bites: Avoid the outdoors at dawn and dusk, when mosquitoes are most active. Set up an outdoor fan to shoo bugs away. And wear long trousers and shirts if it's not too hot. Dr. Zwiebel also suggests spraying your clothing with repellent that contains DEET, a chemical that acts to confuse the mosquito's olfactory receptors. 'It works, and until something better comes along, it's the best thing available to prevent bites,' he says.
其他可用來避開蚊蟲叮咬的方法有：避免在黎明與黃昏時分呆在室外，因爲蚊子在這些時間最爲活躍；安裝室外風機來驅趕蚊蟲；如果天氣不是太熱，可穿長褲和長袖衣服。茨維伯爾還建議，可在衣服上噴些含避蚊胺(DEET)的驅蚊劑，避蚊胺這種化學物可發揮功效迷惑蚊子的嗅覺受體。茨維伯爾說：“它很有效果，在更好的東西出現之前，它是目前可用的防蚊子叮咬的最佳產品。”