Hepatitis1

 

Broadcast: Feb 4, 2003
By Mario Ritter

VOICE ONE:

This is Sarah Long.

VOICE TWO:

And this is Doug Johnson with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Today, we tell about five forms of hepatitis, a viral disease that attacks the liver.

VOICE ONE:

Very different viruses that spread through body waste or body fluids cause hepatitis. Different kinds of hepatitis can only be identified by tests that show infection-fighting molecules¹, called antibodies, in the blood. All hepatitis viruses attack and destroy liver cells.

At one time, only developing nations suffered severe health problems caused by the hepatitis viruses. Today, scientists have identified five viruses that cause hepatitis. These viral diseases have become a major health problem for all nations and social groups.

VOICE TWO:

Hepatitis A is a virus that infects people who come in contact with waste from an infected person. It is usually spread through human waste in food or water. It is believed to be one of the oldest known diseases. It is in the same group of viruses that causes polio. The hepatitis A virus causes fever, tiredness, and pain. It also causes problems with the stomach and intestines² making it difficult to eat or process food. The skin of a person infected with hepatitis A may turn yellow because the person's liver does not work normally.

Hepatitis A can spread quickly, affecting tens of thousands of people. However, the disease is deadly in less than one percent of cases. Many people can have the antibodies to this disease and yet never become sick from it. In the United States, hepatitis A is decreasing because of preventive measures. There is a vaccine³ medicine that can prevent the disease. Some states require that children be vaccinated⁴ for the disease.

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VOICE ONE:

The second form of the disease is hepatitis B. This virus is more dangerous than virus A. Hepatitis B is one of a group of viruses that include herpes and smallpox⁵. The hepatitis B virus also has been linked to liver cancer. For this reason, the World Health Organization considers the hepatitis B vaccine to be the first vaccine against a cancer in humans.

Hepatitis B is spread when blood or body fluids of an infected person enter the body of another person. The disease can spread quickly through sex. It also can spread among people who share needles to inject drugs into the blood. It also can be transferred through blood products. It can even be spread through fluids from the nose or mouth.

In the United States, children are now vaccinated against hepatitis B at an early age. This has helped to control the spread of the disease in this country. Around the world, however, three-hundred-fifty-million people are believed to be severely⁶ infected with the hepatitis B virus. About one-million people die from the disease every year.

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VOICE TWO:

A third form of hepatitis is even more deadly. Hepatitis C belongs to a group of viruses that includes yellow fever and West Nile virus. It is spread mainly by direct contact with infected human blood. Health experts say the main causes of infection have been infected blood given to patients during operations and medical needles that have not been cleaned correctly. People who share needles used to inject drugs into the blood can infect each other. The disease is also spread through sex.

Hepatitis C is dangerous because about eighty percent of those who become infected with the virus develop a severe form of the disease. More than ten percent of those who show effects of the disease develop severe liver damage. As many as five percent of those people develop liver cancer.

VOICE ONE:

There is no vaccine to prevent hepatitis C. Several blood tests can show if the virus is present. Hepatitis C has become a major problem in industrial and developing countries. The World Health Organization estimates that about one-hundred-seventy-million people are infected around the world. The highest infection rates are in Africa, the eastern Mediterranean⁷ and the western Pacific.

VOICE TWO:

In the United States, hepatitis C remains⁸ a great concern. Last year, the National Institutes of Health reported on developments in the treatment of the C virus. The report found that at least four-million Americans have the disease.

Hepatitis C was first observed in nineteen-seventy-four. At the time it was considered an unusual kind of hepatitis. The disease was not officially recognized until nineteen-eighty-nine.

The spread of the disease was largely brought under control by nineteen-ninety-two because of medical testing of blood and tissue products. Until that time, many people became infected when they received some kinds of blood products.

VOICE ONE:

The N-I-H study discovered high numbers of infected people in some groups, including homeless people and prisoners. Between fifteen and fifty percent of the people in these groups are believed to be infected.

People who inject illegal drugs are another high-risk group. So are people with the blood disease hemophilia who received blood products before nineteen-ninety-two. These groups have the highest percentage of infected people. Death documents suggest that as many as twelve-thousand people die of hepatitis C every year in America.

The N-I-H report states that treatment with two drugs used together appears to help infected patients. The drugs are ribavirin2 and interferon. Interferon is also known to fight some cancers. However, interferon and ribavirin are costly⁹ and require careful medical support.

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VOICE TWO:

Two other forms of hepatitis viruses have been linked to liver disease. Hepatitis D can only infect people who have already been infected with hepatitis B. It also spreads in the same way as hepatitis B. The hepatitis D virus greatly increases the chance of severe liver damage.

The World Health Organization says that ten-million people around the world are infected with hepatitis D. The organization says the disease is spreading in places where hepatitis B is present. However, medical scientists have not done much research on the virus because it has been identified only recently.

VOICE ONE:

The fifth kind of virus is hepatitis E. It is spread in the same way as hepatitis A -- through contact with infected human waste. This often happens when human waste pollutes water supplies. In developing countries, outbreaks of hepatitis caused by infected water are now suspected to be hepatitis E rather than hepatitis A.

Hepatitis E was first recognized as a separate disease from hepatitis A in nineteen-eighty.

VOICE TWO:

Studies have shown that the E virus shares qualities of several very different viruses. It can also infect many kinds of animals including pigs, cows and monkeys. It is possible that the disease can be spread from animals to humans.

There is no vaccine for hepatitis E. No medicine currently¹⁰ exists to treat the disease. Hepatitis E can cause liver damage like the other forms of hepatitis. It may cause death in up to four percent of severe cases. However, it is very dangerous for pregnant¹¹ women. The death rate among pregnant women is twenty percent. Hepatitis E is not known in the United States. But it has caused outbreaks in Asia, Africa, and Mexico.

(MUSIC)

VOICE ONE:

There is no cure for any form of hepatitis. Vaccination¹² can greatly reduce the risk of severe infection from the A and B virus. The only way to protect against infection is to avoid contact with the viruses. Experts say people should avoid any kind of injection with dirty needles or medical instruments. They should also avoid sexual¹³ contact with people who may be at risk. Food and water supplies should be protected from pollution by human waste.

Also, blood supplies must be tested for the viruses. People who are in high-risk groups or who have had the disease should not give blood or blood products. Experts say careful preventive measures are the only way to control the spread of the hepatitis viruses.

VOICE TWO:

This SCIENCE IN THE NEWS program was written by Mario Ritter. It was produced by George Grow. This is Doug Johnson.

VOICE ONE:

And this is Sarah Long. Join us again next week for more news about science in Special English on the Voice of America.
1. hepatitis [7hepE5taItIs] n. [医]肝炎
2. ribavirin  [9raIbE`vaILrIn] n. [药]三(氮)唑核苷,病毒唑(抗病毒药)

1 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

2 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

3 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。

4 vaccinated   

[医]已接种的，种痘的，接种过疫菌的

参考例句：

• I was vaccinated against tetanus. 我接种了破伤风疫苗。
• Were you vaccinated against smallpox as a child? 你小时候打过天花疫苗吗？

5 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？

6 severely   

adv.严格地；严厉地；非常恶劣地

参考例句：

• He was severely criticized and removed from his post.他受到了严厉的批评并且被撤了职。
• He is severely put down for his careless work.他因工作上的粗心大意而受到了严厉的批评。

7 Mediterranean   

adj.地中海的；地中海沿岸的

参考例句：

• The houses are Mediterranean in character.这些房子都属地中海风格。
• Gibraltar is the key to the Mediterranean.直布罗陀是地中海的要冲。

8 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。

9 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。

10 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。

11 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。

12 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。

13 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。