VOA标准英语2011--Scientists Target Mosquito-Borne Illness

Scientists Target Mosquito-Borne Illnesses

Of all the disease-spreading insects in the world, the mosquito poses the greatest menace, according to the World Health Organization (WHO). As if to underscore that threat, two mosquito-borne viral diseases have begun to spread well beyond their points of origin. One is dengue fever, a potentially deadly illness, and the other is chikungunya, a debilitating¹ and painful disease from which most people can recover. There are no vaccines³ to prevent these diseases. But researchers are working hard to develop vaccines against dengue fever and chikungunya, and to control the mosquitoes that spread them.
Scientists have identified at least 3,000 different species of mosquitoes throughout the world. The Asian tiger mosquito is one that bites during the day.
The tiger mosquito's bite is more than annoying. It's responsible for infecting 20 million people a year with dengue fever, a flu-like illness that can result in hemorrhagic fever, shock syndrome⁴, and even death.
"It's almost completely spread throughout the tropics and subtropics throughout the world," said Weaver⁵.
Scott Weaver at the University of Texas Medical Branch confirms what other scientists are seeing, mosquitoes that can transmit dengue fever have spread though India, Southeast Asia and Latin America and are finding their way around the world. There were more than 12 confirmed cases this year in Florida, in the southeastern United States.
The tiger mosquito can also spread chikungunya, a debilitating disease that causes extreme joint⁶ pain and fever. The illness is spread as well by an African mosquito, which is also expanding its range. Professor Laura Harrington is an insect specialist at Cornell University. She says it's not just the mosquitoes' range that's changing:
"We're also seeing changes, particularly with the viruses; we're seeing changes in their genetic⁷ material which often can lead to increased virulence," Harrington noted⁸.
On top of that, mosquitoes can arrive in new destinations aboard planes and in cars.
"It's a virus that has the ability to travel on airplanes and in infected people very readily," Weaver added.
Weaver is working on a vaccine² for chikungunya that has successfully protected lab mice from getting the virus. At Cornell, Harrington is working to make the male mosquito infertile⁹.
"The idea is that these modified males that don't take a blood meal could be released, mate with the wild females, the females wouldn't reproduce, they wouldn't take a blood meal, and the population would be eliminated or reduced," Harrington explained.
Both scientists are concerned that if a way to control the spread of chikungunya and dengue fever is not found soon, both diseases will become established in the United States. Harrington says that techniques that prove successful against these illnesses might also be used to break the cycle of other mosquito-borne diseases, including malaria¹⁰.

1 debilitating   

a.使衰弱的

参考例句：

• The debilitating disease made him too weak to work. 这个令他衰弱的病，使他弱到没有办法工作。
• You may soon leave one debilitating condition or relationship forever. 你即将永远地和这段霉运说拜拜了。

2 vaccine   

n.牛痘苗，疫苗；adj.牛痘的，疫苗的

参考例句：

• The polio vaccine has saved millions of lives.脊髓灰质炎疫苗挽救了数以百万计的生命。
• She takes a vaccine against influenza every fall.她每年秋季接种流感疫苗。

3 vaccines   

疫苗，痘苗( vaccine的名词复数 )

参考例句：

• His team are at the forefront of scientific research into vaccines. 他的小组处于疫苗科研的最前沿。
• The vaccines were kept cool in refrigerators. 疫苗放在冰箱中冷藏。

4 syndrome   

n.综合病症；并存特性

参考例句：

• The Institute says that an unidentified virus is to blame for the syndrome. 该研究所表示,引起这种综合症的是一种尚未确认的病毒。
• Results indicated that 11 fetuses had Down syndrome. 结果表明有11个胎儿患有唐氏综合征。

5 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。

6 joint   

adj.联合的，共同的；n.关节，接合处；v.连接，贴合

参考例句：

• I had a bad fall,which put my shoulder out of joint.我重重地摔了一跤，肩膀脫臼了。
• We wrote a letter in joint names.我们联名写了封信。

7 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

8 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

9 infertile   

adj.不孕的；不肥沃的，贫瘠的

参考例句：

• Plants can't grow well in the infertile land.在贫瘠的土地上庄稼长不好。
• Nobody is willing to till this infertile land.这块薄田没有人愿意耕种。

10 malaria   

n.疟疾

参考例句：

• He had frequent attacks of malaria.他常患疟疾。
• Malaria is a kind of serious malady.疟疾是一种严重的疾病。