SCIENCE IN THE NEWS - Malaria

SCIENCE IN THE NEWS -June 4, 2002: Malaria¹

By Oliver Chanler

VOICE ONE:
This is Bob Doughty².
VOICE TWO:
And this is Sarah Long with Science in the News, a VOA Special English program about recent developments in

Science. Today, we tell about malaria, a disease that affects millions of people around the world.
((THEME)
)
VOICE ONE:
Malaria is a common and serious disease that has affected³ people for thousands of years. Today, it continues to

be a major public health problem throughout the world. It is most common in developing countries, especially in

Africa, Asia, and Central and South America.
The World Health Organization estimates that as many as five-hundred-million cases of malaria develop each
year. More than one-million people die from the disease each year. Most of them are children in African
countries.

VOICE TWO:
Malaria is spread by a common insect, the mosquito. The Anopheles mosquito carries the parasite⁴ that causes the
disease. Very small parasites⁵ 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 male Anopheles mosquitoes feed
only on plant juices.

VOICE ONE:

The female Anopheles mosquito drinks blood from humans and animals by breaking through the skin with its
long, tube-like feeding device. The parasites enter the victim’s blood. The blood carries the parasites to the
victim’s liver. From there they invade cells and reproduce⁶.

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, headache, chills⁷ and shaking. Patients with severe malaria may develop liver and kidney⁸ failure,
seizures⁹ and coma¹⁰.

((MUSIC BRIDGE))

VOICE TWO:

These signs of malaria have been observed since the beginning of history. Researchers studying 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. However, the real cause of the disease
was unknown to ancient peoples.


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 the spread of malaria. 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 humans. More exactly, he discovered that insects carry the parasites and pass them to
humans.

In Eighteen-Eighty, 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 scientific 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 try to end the disease completely.

VOICE TWO:

Between Nineteen-Fifty-Five and Nineteen-Sixty-Nine, the World Health Organization’s Global Malaria

Eradication¹⁷ Program carried out 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 Soviet¹⁸ Union and some parts of Asia and South America. The spread of the disease in these
areas was halted.

However, the disease continued in Central America, some parts of South America,
and most Asian countries. The W-H-O program never was attempted in Africa. This
is because it was too difficult and costly¹⁹ for most African countries.

VOICE ONE:

In Nineteen-Sixty-Eight, malaria suddenly spread rapidly among people in Sri

Lanka, where it was believed the disease no longer existed. The disease also spread
in Central America and Southeast Asian countries, as well as 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.

((MUSIC BRIDGE))

VOICE TWO:

There are four different kinds of malaria. They are caused by four different kinds of parasites. Three kinds of
parasites 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.

(Picture -Nico Colombant/VOA)

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.

Well 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 researchers 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 of the world 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.

Although these drugs are effective in preventing malaria, great numbers of people still die every year from the
disease. In almost all cases, this is because of delayed treatment or no treatment at all. International health
organizations are increasing efforts to reduce the deaths from malaria in the next ten years.

((THEME))

VOICE ONE:

This SCIENCE IN THE NEWS program was written by Oliver Chanler. It was produced by George Grow. This
is Bob Doughty.

VOICE TWO:

And this is Sarah Long. Join us again next week for more news about science in Special English on the Voice of
America.

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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 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。

3 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

4 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。

5 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。

6 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。

7 chills   

寒冷( chill的名词复数 )； 冷漠； 扫兴； [冶金学]激冷

参考例句：

• These evening damps and chills play Old Harry with one's bronchial tubes. 夜晚的湿气与寒冷对支气管有害。
• The bitter wind chills one to the bone. 寒风彻骨。

8 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。

9 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

10 coma   

n.昏迷，昏迷状态

参考例句：

• The patient rallied from the coma.病人从昏迷中苏醒过来。
• She went into a coma after swallowing a whole bottle of sleeping pills.她吃了一整瓶安眠药后就昏迷过去了。

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 eradication   

n.根除

参考例句：

• The eradication of an established infestation is not easy. 根除昆虫蔓延是不容易的。
• This is often required for intelligent control and eradication. 这经常需要灵巧的控制与消除。

18 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。

19 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。