生活研究:哪种人是蚊子的最爱?

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.

眼下正是蚊子活动的高峰期，有些在室外活动的幸运儿好像并不受这种小小昆虫的侵扰，而另一些人则似乎不断遭到它们的侵袭。科学家们就什么原因导致某些人更吸引这些恼人的东西进行了探索。其中一名专家──范德堡大学(Vanderbilt University)生物学教授、分子载体生物学家L.J.茨维伯尔(L. J. Zwiebel)也加入了讨论。

Sweet Smell of Success

人体气味 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.

蚊子通过感知哺乳动物释放出的热量和二氧化碳来寻找它们的“猎物”。有时候，怀孕女性与体型较大的人会遭到蚊子多次侵袭，因为他们会比普通人散发出更多能量。

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，蚊子也受到它们嗅觉的指引。茨维伯尔说：“不管我奶奶以前对我讲过什么，但是我的血肯定不香甜，”这是因为蚊子并不能辨别血液的品质。他指出：“蚊子是被我们人类的气味吸引的，这主要是因为我们皮肤上有细菌。”他说，“我们皮肤上菌群”的气味也吸引蚊子，当我们出汗或在室外呆了很长时间后，这些菌群的数量就会增加。

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.

就茨维伯尔所知，尽管某些网站报道称高胆固醇或糖尿病可防范蚊子，但这一说法并无科学证明。此外，服用维生素B、吃大蒜或服用某些药物可驱蚊的说法也没有科学依据。

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.

茨维伯尔在实验室中与这种咬人的昆虫呆了20年时间，他说他能把胳膊伸进一个装有蚊子的容器中，被咬上几百次也“毫发无损”。儿童被蚊子叮咬的频率低于成年人，但他们对叮咬的反应可能会更强烈，因为他们的免疫系统尚未完全成熟。常常有些确信自己被这种“吸血虫”侵害的成年人其实并没遭到叮咬。茨维伯尔指出：“有些人会对叮咬产生强烈的过敏反应，这可能会使他们显得更经常遭受叮咬，但也许事情并非如此。”

Fighting Back

人体的反击

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.

对于出现红肿和发痒伤口的人，茨维伯尔建议他们不要抓挠伤口。蚊子在叮人时会留下一些唾液及其他物质，其中它的唾液含有抗凝血剂和一种局部麻醉成分。人体会把唾液认作外来入侵物，释放出组胺来予以反击。抓挠伤口只会使唾液扩散，引发身体释放出更多抗体，让伤口变得更痒，由此引发恶性循环。

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.

茨维伯尔建议，那些遭蚊虫叮咬后伤口肿胀或伤口非常痒的人，“应与医生谈谈，看看是否需要每天服用一种非处方抗组胺剂用于预防”。服用该药物后，蚊子仍会咬你，不过你可能就注意不到了，因为它可预防过敏反应，从而避免无痛的叮咬发展为恼人的痒痛。

Cleaner Is Meaner

清洁抗菌

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们的繁殖周期、产下幼卵（这需要大量补充蛋白质）时，雌蚊子便会去咬人。若要降低被蚊子叮咬的几率，可用抗菌香皂清洗身体以减少皮肤表面吸引蚊子的细菌的数量。

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.

其他可用来避开蚊虫叮咬的方法有：避免在黎明与黄昏时分呆在室外，因为蚊子在这些时间最为活跃；安装室外风机来驱赶蚊虫；如果天气不是太热，可穿长裤和长袖衣服。茨维伯尔还建议，可在衣服上喷些含避蚊胺(DEET)的驱蚊剂，避蚊胺这种化学物可发挥功效迷惑蚊子的嗅觉受体。茨维伯尔说：“它很有效果，在更好的东西出现之前，它是目前可用的防蚊子叮咬的最佳产品。”