SCIENCE IN THE NEWS - Scientists Meet in Cameroon to Discuss

SCIENCE IN THE NEWS - Scientists Meet in Cameroon to Discuss Malaria¹
By Oliver Chanler and Caty Weaver²

Broadcast: Tuesday, November 22, 2005

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VOICE ONE:

This is SCIENCE IN THE NEWS in V.O.A. Special English. I'm Bob Doughty³.

VOICE TWO:

And I'm Pat Bodnar. Hundreds of scientists, health care experts and policy makers⁴ met in Cameroon last week to talk about the deadly disease malaria. Today, we tell about that conference. We also explain the causes of and treatments for malaria.

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VOICE ONE:

A group called the Multilateral Initiative⁵ on Malaria organized the conference in Yaounde, Cameroon. Sixty-five countries were represented at the six days of meetings.

 
Malaria conference
The representatives met in the continent most troubled by malaria. Each year, the disease kills more than one million people. Most of those killed are children in Africa. Health experts say malaria kills one African child every thirty seconds.

VOICE TWO:

A common insect, the mosquito, is responsible for the spread of malaria. The Anopheles mosquito carries the parasite⁶ that causes the disease. Very small parasites⁷ develop in the stomach of the mosquito. Parasites are organisms that live on or in another animal and get their food from that animal.

The general name for the malaria parasite is Plasmodium. Mosquitoes pass the parasites to people when they drink blood through the skin. However, only the female Anopheles mosquitoes drink blood. The males feed only on plant juices.

VOICE ONE:

 
 
The female Anopheles mosquito drinks blood from people and animals by breaking through the skin with its long, tube-like feeding device. The parasites enter the blood of the victim. The blood carries the parasites to the victim's liver. From there they invade cells and reproduce⁸.

After nine to sixteen days, the parasites return to the blood and enter the red blood cells. Then they reproduce again. As they do this, they destroy the blood cells. In a short time, the victim develops a high body temperature. The victim becomes weak and is unable to carry out normal activities.

Other signs of malaria include pain in the muscles or head and shaking. Patients with severe malaria may develop liver and kidney⁹ failure, seizures¹⁰ and become unable to communicate.

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VOICE TWO:

These signs of malaria have been observed since the beginning of history. Scientists examining bodies of ancient Egyptians have found evidence of the disease in people who lived at least three thousand years ago. And scientists have found mosquitoes in fossil¹¹ remains¹² millions of years old.

At one time, it was believed that malaria was caused by bad air. People believed this bad air came from areas of water that were not deep and did not move. It seemed that malaria was most common near these swamps¹³.

Ancient people suspected that mosquitoes were linked to malaria. The Greek historian¹⁴ Herodotus lived about two thousand four hundred years ago. He noted¹⁵ that in swampy¹⁶ areas of Egypt, some people slept in tall structures where mosquitoes could not go. Or they slept under special material called nets that mosquitoes could not go through.

VOICE ONE:

In eighteen seventy-six, British scientist Patrick Manson discovered that mosquitoes were responsible for passing the disease to human beings. More exactly, he found that insects carry the parasites and pass them to humans.

In eighteen eighty, a French doctor, Alphonse Laveran, discovered that the Plasmodium parasite causes the disease. In eighteen ninety-seven, a British scientist, Ronald Ross, found the malaria parasite in the Anopheles mosquito.

For his discovery of the cause of malaria and other work, Doctor Laveran received the Nobel Prize for Medicine in nineteen-oh-seven. Mister Ross received the Nobel Prize for Medicine in nineteen-oh-two for his work on malaria. The discoveries of the three scientists soon led to efforts to control malaria. Then, the discovery of the insect poison D-D-T led to efforts to end the disease completely.

VOICE TWO:

Between nineteen fifty-five and nineteen sixty-nine, the World Health Organization organized a series of campaigns against the disease. The goal was to use chemicals to kill mosquitoes inside homes around the world.

The effort was successful in large areas of North America, southern Europe, the former Soviet¹⁷ Union and some parts of Asia and South America. The spread of the disease in these areas was halted.

However, the disease remained in Central America, parts of South America, and some Asian countries. The W-H-O program never was attempted in Africa. This is because it was too difficult and costly¹⁸ for most African countries.

VOICE ONE:

In nineteen sixty-eight, malaria suddenly spread among people in Sri Lanka, where it was believed the disease no longer existed. The disease also spread in Central America, in Southeast Asian nations, and in parts of Africa.

Efforts to end malaria throughout the world were suspended in nineteen sixty-nine. Today, the W-H-O says that malaria control programs must be developed for local areas. It says such programs must involve everyone in each community -- citizens, health experts and people involved in development.

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VOICE TWO:

There are four different kinds of malaria. They are caused by four different kinds of parasites. Three of them cause victims to suffer high body temperatures, or fevers, every few days. But they do not cause death. However, the most common malaria parasite also is the most dangerous. This parasite causes infections that can lead to death.

The best way to prevent malaria is to avoid the mosquitoes that carry the malaria parasites. The female Anopheles mosquito takes blood from its victims mainly at night.

So, people can place special nets treated with insect poison over their beds at night while they sleep. People can also put anti-insect chemicals on their skin, on clothing and in sleeping areas. They also can wear clothes that cover most of the body.

VOICE ONE:

If the mosquitoes get past barriers used to block them, drugs are necessary for treatment. Drugs can destroy the malaria parasite as soon as it enters the human body. This prevents the parasites from entering the red blood cells and dividing.

Some drugs can prevent the parasite from establishing itself in the liver. However, malaria must be treated early for the treatment to be effective.

Before the fifteenth century, people in what is now Peru knew that the covering or bark from the cinchona tree was effective in treating the signs of malaria. In eighteen-twenty, two French scientists identified the substance in the bark as quinine. Until the twentieth century, quinine was the chief drug used to prevent and cure some forms of malaria.

Today, manufactured drugs are mostly effective in treating the disease. These drugs are designed to prevent the parasites from developing in the body and causing malaria.

VOICE TWO:

The most commonly used malaria prevention drug is chloroquine. It is suggested for use in Mexico, Central America, Haiti, the Dominican Republic, and the Middle East. Another drug, called mefloquine, is used in all other areas where malaria is a threat. Both drugs must be taken once a week on the same day each week. Another commonly used anti-malaria drug is doxycycline. It must be taken every day.

Scientists are currently¹⁹ testing a medicine to protect humans from malaria. In Cameroon, scientists said the medicine has protected children from the disease for as long eighteen months. One thousand four hundred children in Mozambique were involved in the study. The boys and girls were given the protective medicine, or vaccine²⁰, in two thousand three. They were then observed for a year and a half.

Doctors say the vaccine reduced the total number of malaria cases by thirty-five percent. They also said life threatening cases of malaria were cut by almost fifty percent. The drug company GlaxoSmithKline is developing the vaccine.

VOICE ONE:

Conference delegates²¹ discussed other ideas for malaria prevention and treatment. But they said much more work is needed. Aid groups have offered to help in those efforts.

The largest amount of new money for the fight against malaria was announced before the conference. The Bill and Melinda Gates Foundation said it would provide more than one hundred million dollars for continued research on the Glaxo-Smith-Kline vaccine. The rest will go to other malaria research and prevention methods.

 
Bill & Melinda Gates
Bill Gates is the richest man in the world. He told reporters that malaria can be defeated. And, he said it would be fought harder if the children dying from were in rich countries.

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VOICE TWO:

This program was written by Oliver Chanler and Caty Weaver. She also was the producer. I'm Pat Bodnar.

VOICE ONE:

And I'm Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.

1 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。

2 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。

3 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

4 makers   

n.制造者，制造商（maker的复数形式）

参考例句：

• The makers of the product assured us that there had been no sacrifice of quality. 这一产品的制造商向我们保证说他们没有牺牲质量。
• The makers are about to launch out a new product. 制造商们马上要生产一种新产品。 来自《简明英汉词典》

5 initiative   

n.主动性，首创精神，主动权（的行动），倡议

参考例句：

• He went to see the headmaster on his own initiative.他主动去看望校长。
• His employer had described him as lacking in initiative and drive.雇主说他缺乏进取心和干劲。

6 parasite   

n.寄生虫；寄生菌；食客

参考例句：

• The lazy man was a parasite on his family.那懒汉是家里的寄生虫。
• I don't want to be a parasite.I must earn my own way in life.我不想做寄生虫，我要自己养活自己。

7 parasites   

寄生物( parasite的名词复数 )； 靠他人为生的人； 诸虫

参考例句：

• These symptoms may be referable to virus infection rather than parasites. 这些症状也许是由病毒感染引起的，而与寄生虫无关。
• Kangaroos harbor a vast range of parasites. 袋鼠身上有各种各样的寄生虫。

8 reproduce   

v.生育，繁殖，复制，重做

参考例句：

• The machine can reproduce a key in two minutes.这机器能在两分钟内复制一把钥匙。
• The picture will reproduce well.这照片会印得很清楚。

9 kidney   

n.肾，腰子，类型

参考例句：

• Several of the patients had received kidney transplant.病人中有几位已接受了肾移植手术。
• The operation to transplant a kidney is now fairly routine.肾脏移植手术如今已相当常见。

10 seizures   

n.起获( seizure的名词复数 )；没收；充公；起获的赃物

参考例句：

• Seizures of illicit drugs have increased by 30% this year. 今年违禁药品的扣押增长了30%。 来自《简明英汉词典》
• Other causes of unconsciousness predisposing to aspiration lung abscess are convulsive seizures. 造成吸入性肺脓肿昏迷的其他原因，有惊厥发作。 来自辞典例句

11 fossil   

n.化石，食古不化的人，老顽固

参考例句：

• At this distance of time it is difficult to date the fossil.时间隔得这么久了，很难确定这化石的年代。
• The man is a fossil.那人是个老顽固。

12 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

13 swamps   

沼泽（地）( swamp的名词复数 )

参考例句：

• On the floor of the basins lie deserts, lakes and swamps. 这几个盆地的底部有沙漠、湖泊和沼泽。
• The lowest parts of the flood plain may form "back-swamps". 河漫滩最低的部分可以形成河漫滩沼泽。

14 historian   

n.历史学家，编史家

参考例句：

• As a historian,he was most typical of the times in which he lived.作为历史学家，他是他所处时代最有代表性的人物。
• He calls himself a historian,but his books are a mere journalism.他自称为历史学家，但是他的书都是些肤浅的通俗作品。

15 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。

16 swampy   

adj.沼泽的，湿地的

参考例句：

• Malaria is still rampant in some swampy regions.疟疾在一些沼泽地区仍很猖獗。
• An ox as grazing in a swampy meadow.一头牛在一块泥泞的草地上吃草。

17 Soviet   

adj.苏联的，苏维埃的；n.苏维埃

参考例句：

• Zhukov was a marshal of the former Soviet Union.朱可夫是前苏联的一位元帅。
• Germany began to attack the Soviet Union in 1941.德国在1941年开始进攻苏联。

18 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

19 currently   

adv.通常地，普遍地，当前

参考例句：

• Currently it is not possible to reconcile this conflicting evidence.当前还未有可能去解释这一矛盾的例证。
• Our contracts are currently under review.我们的合同正在复查。

20 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。

21 delegates   

代表，代表团成员( delegate的名词复数 )

参考例句：

• The conference was attended by delegates from 56 countries. 此次会议有来自56个国家的代表出席。
• Delegates expressed strong opposition to the plans. 代表强烈反对这些计划。