VOA慢速英语-SCIENCE IN THE NEWS - Six Different Liver Diseases,

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Steve Ember.

VOICE TWO:

And I'm Shirley Griffith. This week, we will tell about six diseases² of the liver³. The six diseases come from six different viruses. Doctors have one name for all of them: hepatitis.

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VOICE ONE:
　
A boy gets a hepatitis B vaccination⁴ in Lima, Peru, in April

The liver is in the upper right part of the stomach. This dark, red organ is big. It weighs more than one kilogram. And, it has a big job. The liver helps clean the blood and fight infection. It also helps break down food and store energy until the body needs it.

Hepatitis destroys liver cells. Some kinds of hepatitis are much more serious than others. Scientists have identified the six kinds of hepatitis with the letters A, B, C, D, E and G. Which kind a person has can only be known from tests for antibodies in the blood.

Antibodies are special proteins that the body's natural defenses against disease¹ produce in answer to a threat. Identify the antibody and you identify the threat.

VOICE TWO:

Hepatitis A is usually spread through human waste in water or food. It is in the same group of viruses as those that cause the disease polio.

The hepatitis A virus causes high body temperature, weakness and pain. It causes problems with the stomach and intestines⁵, making it difficult to eat or break down food. Also, the skin of a person with hepatitis may become yellow. This is a sign that the liver is not operating normally⁶.
　
Hand washing can prevent the spread of hepatitis A

To help prevent the spread of hepatitis A, people should wash their hands after they use the restroom or change a baby's diaper. People should also wash their hands before they eat or prepare food.

VOICE ONE:

Hepatitis A can spread quickly to hundreds or thousands of people. But the virus is deadly in less than one percent of cases. Many people infected with the virus never even get sick. But those who do generally recover within two months.

The World Health Organization says hepatitis A is often found in Africa, Asia and Central and South America. People who have had hepatitis A cannot get it again. There is a vaccine⁷ to prevent hepatitis A. America's Centers for Disease Control says the vaccine is the best way to protect against the disease.

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VOICE TWO:

The World Health Organization says as many as two billion people are infected with the hepatitis B virus. More than three hundred fifty million of those infected have lifelong infections. W.H.O. officials say an estimated⁸ six hundred thousand people die each year as a result of hepatitis B.

The virus is in the same group as the herpes and smallpox⁹ viruses. Hepatitis B vaccines¹⁰ have been given since the nineteen eighties. The W.H.O. says the vaccine is ninety five percent effective in preventing the development of infection in both children and adults.

VOICE ONE:

Hepatitis B spreads when blood from an infected person enters the body of another person. An infected mother can infect her baby. The virus can also spread through sexual¹¹ activity, and if people share injection¹² devices¹³.

Blood products from an infected person can spread hepatitis B. People also can get infected if they share personal-care products that might have blood on them. Examples include toothbrushes and hair-cutting instruments.

VOICE TWO:

Worldwide, most hepatitis B infections are found in children. Young children are the ones most likely to develop a lifelong, or chronic¹⁴, infection. The risk of such an infection is small for children older than four years.

About ninety percent of babies infected with hepatitis B during the first year develop chronic infections. Such persons are at high risk of death from liver disease or liver cancer. The hepatitis B vaccine is considered to be the first medicine that can protect people against liver cancer.

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VOICE ONE:

Hepatitis C is even more dangerous. Like hepatitis B, it spreads when blood from an infected person enters someone who is not infected.

The hepatitis C virus belongs to the same group of viruses as yellow fever and West Nile virus. Most people living with hepatitis C develop chronic infections, often without any signs. They are at high risk for liver disease and liver cancer.

The World Health Organization says about one hundred seventy million people are infected with hepatitis C. That is three percent of the population of the world! The W.H.O. also says that as many as four million more become infected each year. It warns that those infected may develop diseases of the liver, including liver cancer. The W.H.O. says the highest rates of infection are in Africa, Asia, and Central and South America.

VOICE TWO:

Scientists have been working to develop a vaccine against hepatitis C. The virus was first observed in nineteen seventy-four. But it was not officially recognized as a new kind of hepatitis until nineteen eighty-nine.

The Centers for Disease Control says about three million Americans are infected with hepatitis C. It says that those especially at risk include persons who inject themselves with drugs and those who received blood or blood products before nineteen ninety.

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VOICE ONE:

Hepatitis D is spread through blood, but only infects people who already have hepatitis B. The hepatitis D virus greatly increases the chance of severe liver damage. Experts say the virus infects about fifteen million people around the world. They say it also appears in five percent of persons infected with hepatitis B.

Doctors say the best way to prevent hepatitis D is to get vaccine that protects against hepatitis B. Doctors can treat some cases of hepatitis B, C and D. The drugs used are costly¹⁵, however. But they are less costly than another treatment: getting a new liver.

VOICE TWO:

The fifth virus is hepatitis E. Experts say it spreads the same way as hepatitis A -- through infectious¹⁶ waste. Cases often result from polluted supplies of drinking water. Medical science recognized hepatitis E as a separate disease in nineteen eighty.

Hepatitis E is also found in animal waste. Studies have shown that the virus can infect many kinds of animals.

VOICE ONE:

The W.H.O. says many hepatitis E cases have been reported in Central and Southeast Asia, North and West Africa and Mexico. No vaccines or medicines are effective against hepatitis E. Most people recover, usually in several weeks or months. But the disease can cause liver damage. And, in some cases, hepatitis E can be deadly.

The virus is especially dangerous to pregnant¹⁷ women. Twenty percent of such women living with hepatitis E die in the last three months of pregnancy¹⁸.

VOICE TWO:

Scientists discovered yet another kind of hepatitis in the nineteen nineties. It has been named hepatitis G. The hepatitis G virus is totally different from any of the other hepatitis viruses.

Donald Poretz is an infectious disease specialist in Washington, D.C. He says the hepatitis G virus is spread through blood and blood products. But he says the virus has not been found to cause any real disease.

VOICE ONE:

The World Hepatitis Alliance¹⁹ works²⁰ to increase knowledge about the dangers of hepatitis. The group says people should know that the disease kills about one million five hundred thousand people each year. It also says one in twelve people worldwide are living with hepatitis B or hepatitis C. And, it says, most of those infected do not even know it.

Hepatitis cannot be cured. The only way to protect against infection is to receive vaccines against hepatitis A and B, and to avoid contact with the other viruses. And that may be difficult.

Remember that some kinds of hepatitis spread through sex or sharing needles. Blood products should be carefully tested for hepatitis. People in high-risk groups and those who have had hepatitis should not give blood. They also should not agree to provide their organs to others after they die. Donated organs can also spread hepatitis.

VOICE TWO:

Health experts say people can take other steps to protect themselves. These include always washing your hands with soap and water after using the restroom. Also, wash your hands after changing a baby's diaper and before preparing or eating food.

Experts say travelers should not drink water of unknown quality when visiting foreign or unknown areas. Visitors to such areas also should avoid eating uncooked fruits and vegetables. And, again, do not forget to wash your hands!

(MUSIC)

VOICE ONE:

This SCIENCE IN THE NEWS was written by Nancy Steinbach. Our producer was Brianna Blake. I'm Steve Ember.

VOICE TWO:

And I'm Shirley Griffith. Internet users²¹ can read our reports at voaspecialenglish.com. Listen again next week for more news about science in Special English on the Voice of America.

 

1 disease   

n.疾病，弊端

参考例句：

• The doctors are trying to stamp out the disease.医生正在尽力消灭这种疾病。
• He fought against the disease for a long time.他同疾病做了长时间的斗争。

2 diseases   

n.疾病( disease的名词复数 )；弊端；恶疾；痼疾

参考例句：

• Smoking is a causative factor in several major diseases. 抽烟是引起几种严重疾病的病因。
• The illness frequently coexists with other chronic diseases. 这种病往往与其他慢性病同时存在。

3 liver   

n.肝；肝脏

参考例句：

• He has a weak liver.他的肝脏不好。
• The largest organ in the body is the liver.人体最大的器官是肝脏。

4 vaccination   

n.接种疫苗，种痘

参考例句：

• Vaccination is a preventive against smallpox.种痘是预防天花的方法。
• Doctors suggest getting a tetanus vaccination every ten years.医生建议每十年注射一次破伤风疫苗。

5 intestines   

n.肠( intestine的名词复数 )

参考例句：

• Perhaps the most serious problems occur in the stomach and intestines. 最严重的问题或许出现在胃和肠里。 来自辞典例句
• The traps of carnivorous plants function a little like the stomachs and small intestines of animals. 食肉植物的捕蝇器起着动物的胃和小肠的作用。 来自辞典例句

6 normally   

adv.正常地，通常地

参考例句：

• I normally do all my shopping on Saturdays.我通常在星期六买东西。
• My pulse beats normally.我脉搏正常。

7 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。

8 estimated   

adj．根据估计的

参考例句：

• She estimated the breadth of the lake to be 500 metres. 她估计湖面大约有500米宽。
• The man estimated for the repair of the car. 那人估算了修理汽车的费用。

9 smallpox   

n.天花

参考例句：

• In 1742 he suffered a fatal attack of smallpox.1742年，他染上了致命的天花。
• Were you vaccinated against smallpox as a child?你小时候打过天花疫苗吗？

10 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。

11 sexual   

adj.性的，两性的，性别的

参考例句：

• He was a person of gross sexual appetites.他是个性欲旺盛的人。
• It is socially irresponsible to refuse young people advice on sexual matters.拒绝向年轻人提供性方面的建议是对社会不负责任。

12 injection   

n.注射，注入；注射液

参考例句：

• Those drugs are given by injection as well as through the mouth.那些药品可以注射，也可以口服。
• She pressed the patient a bit too hard when she gave him an injection.她打针时手重了些。

13 devices   

n.设备；装置( device的名词复数 )；花招；（为实现某种目的的）计划；手段

参考例句：

• electrical labour-saving devices around the home 节省劳力的各种家用电器
• modern labour-saving devices such as washing machines and dishwashers 诸如洗衣机和洗碗机之类的现代化省力设备

14 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

15 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。

16 infectious   

adj.传染的，有传染性的，有感染力的

参考例句：

• Influenza is an infectious disease.流感是一种传染病。
• What an infectious laugh she has!她的笑声多么具有感染力啊！

17 pregnant   

adj.怀孕的，怀胎的

参考例句：

• She is a pregnant woman.她是一名孕妇。
• She is pregnant with her first child.她怀了第一胎。

18 pregnancy   

n.怀孕，怀孕期

参考例句：

• Early pregnancy is often accompanied by nausea.怀孕早期常有恶心的现象。
• Smoking during pregnancy increases the risk of miscarriage.怀孕期吸烟会增加流产的危险。

19 alliance   

n.同盟，同盟国，结盟，联姻

参考例句：

• China will not enter into alliance with any big power.中国不同任何大国结盟。
• The new alliance was very much in evidence.新的联盟上星期很引人注目。

20 works   

n.作品，著作；工厂，活动部件，机件

参考例句：

• We expect writers to produce more and better works.我们期望作家们写出更多更好的作品。
• The novel is regarded as one of the classic works.这篇小说被公认为是最优秀的作品之一。

21 users   

用户，使用者( user的名词复数 )

参考例句：

• The new software will prove a boon to Internet users. 这种新软件将会对互联网用户大有益处。
• Ramps should be provided for wheelchair users. 应该给轮椅使用者提供坡道。