VOA慢速英语20060328b

SCIENCE IN THE NEWS - Preparing for a Bird Flu Pandemic: Waiting, Worrying and WonderingBy Karen Leggett

Broadcast: Tuesday, March 28, 2006

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VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty¹.

VOICE TWO:

And I'm Barbara Klein. Our subject this week is bird flu.

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VOICE ONE:

There are many kinds of avian influenza². The one that has many people concerned is caused by the virus h-five-n-one. This virus has killed birds in about forty countries. It is highly³ deadly to chickens, turkeys and other poultry⁴. But birds are not the only ones at risk.


Science in the News

The first known cases in humans appeared in nineteen ninety-seven in Hong Kong. Since two thousand three, the virus has been found in more than one hundred eighty people in at least eight countries. More than one hundred of them have died.

So far, experts say most of the victims have been infected directly from sick birds. But there is concern that the virus could change into a form that spreads easily from one person to another.

VOICE TWO:

Infections have been found in sixty kinds of wild birds. The part that migratory⁵ birds play in spreading the virus is still being studied. Experts still do not know exactly how the virus spread from Asia to Europe and Africa.

Migratory birds fly long distances between a winter home and a summer home. Some researchers say these birds are getting too much blame. But American scientist Robert Webster believes ducks are a big part of the problem. He says ducks might not get sick from bird flu but spread the disease⁶ easily to chickens.

Some experts think the virus could reach the United States in April or May. They say it could arrive when ducks and other wild birds from Asia reach Alaska. Government scientists are testing thousands of wild birds flying across the state.

VOICE ONE:

Animal health experts say people who want to protect chickens and other birds should keep them in closed areas, away from wild birds. Also, farm birds should not drink from water used by wild birds.

If the virus appears, people with special training and protective⁷ clothing should kill all the birds on the farm. The farm must be cleaned completely.

To help prevent an outbreak, people should clean their hands and shoes before and after they visit farms or markets where birds are kept. Washing clothes and equipment after contact with birds is also important.

Any equipment or supplies that are shared with people who keep birds should be cleaned after use. Experts say items made of materials like wood and fiber⁸ should not be shared because they are more difficult to disinfect.

VOICE TWO:

In many places, chickens are kept close to or inside people's homes. This can be an infection risk, especially when children play with them.


Science in the News

People should cover their face and hands when they work with farm birds or wild birds. Facial protection will reduce the risk of breathing dust that might carry the infection. To increase the protection, people should not eat, drink or smoke while working with birds.

Birds that get the virus often die within forty-eight hours. Other possible signs are lack of egg production, or eggs with soft shells; lack of energy; swelling⁹ in the eyes and neck; and a purple color around the legs.

Any suspected cases should be reported to animal health officials immediately.

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VOICE ONE:

You are listening to SCIENCE IN THE NEWS in VOA Special English.

In France, the h-five-n-one virus was found in a wild duck about one kilometer from the farm of a man named Daniel Clair. Soon his chickens also had the virus. But he did not believe the duck was responsible.

Mister¹⁰ Clair blamed reporters. He said they brought the virus to his farm on their shoes after they went to where the dead duck was found.

The infection can spread on shoes, tires, farm equipment, clothes and people's hands. And it can spread whenever birds are transported, either legally or illegally. Illegal trade is a concern because it can sabotage¹¹ efforts to stop an outbreak.

VOICE TWO:

Products made with bird waste are another concern. Bird waste is often used to make fertilizer¹². It is also used as food in fish farming. But untreated waste can spread the infection. In some cases wild birds are believed to have been infected by drinking water in fish farms. Experts say the virus can live in water for three weeks.

The World Health Organization says the virus can be killed in poultry products at a heat of seventy degrees Celsius¹³. The W.H.O. also has other rules for food safety: Wash your hands before eating. Disinfect all equipment and surfaces that are used to prepare food. And do not place uncooked meat next to cooked meat.

VOICE ONE:

There are no warnings to avoid countries with cases of bird flu. But officials do advise travelers not to visit bird farms or have other contact with birds before or during their travels.

Public health officials are trying to prevent a human pandemic. A pandemic is a worldwide outbreak of disease. Pandemics happen when people have no resistance¹⁴ to an aggressive new virus.

Flu pandemics happen from time to time. The worst known was the nineteen eighteen Spanish flu. Many researchers estimate¹⁵ the dead at between twenty million and fifty million. Some say the number could be as high as one hundred million.

Many scientists say the next flu pandemic is likely to be caused by the h-five-n-one virus. Others point out that there is no way to know.

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VOICE TWO:

Influenza viruses continually¹⁶ change. Scientists have to make new vaccines¹⁸ each year to protect people. It takes six months or more to develop a new flu vaccine¹⁷. And even in a normal flu season it takes time to produce enough to meet demand.

Scientists are now working on vaccines to protect people against a possible bird flu pandemic. There is no cure for bird flu, just like other kinds of influenza. Two anti-viral drugs, Tamiflu and Relenza, might help reduce the severity in some cases if taken very soon after a person gets sick.

But, sooner or later, medicines can lose their effectiveness as viruses and bacteria develop resistance. So doctors are being urged to limit the use of Tamiflu and Relenza now in case they are needed for a pandemic.

VOICE ONE:

The World Health Organization is telling all countries to have a plan in case of a pandemic. A good plan must include information about finding¹⁹ enough hospital space for sick people. There must be information about when to close schools or workplaces. And information about when to require people to stay home, and how to get medicine.

But officials say only about forty countries have a plan.

The United States said in January that it will provide three hundred thirty-four million dollars to help other countries deal with outbreaks.

International health officials have been meeting to work on a plan so all nations get vaccines and anti-viral medicines. About thirty countries are buying large amounts of medicine. But right now the W.H.O. says it believes most developing countries will not have enough supplies to deal with a pandemic.

Some medical experts see little chance that even the United States would have enough to prevent a pandemic within the next three years. Others, though, think people worry too much about the h-five-n-one virus.

VOICE TWO:

So why does the animal virus rarely spread from human to human? New reports in Science magazine and Nature offer an explanation. Two separate teams found that the virus is only able to enter cells deep in the lungs.

Human flu viruses attach to cells in the upper part of the breathing system. People then spread the infection from the nose and mouth when they cough and sneeze. The scientists, in the United States, Japan and the Netherlands, note that genetic²⁰ changes would be needed for the h-five-n-one virus to cause a pandemic.

VOICE ONE:

Before we go, here are three sites on the Internet to learn more about avian influenza. One is the Web site of the World Health Organization: who.int.

VOICE TWO:

The second is a United States government site: pandemicflu.gov.

VOICE ONE:

And the third is our Web site, www.unsv.com. You can find a link to the latest news about bird flu.

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VOICE TWO:

SCIENCE IN THE NEWS was written by Karen Leggett and produced by Cynthia Kirk. I'm Barbara Klein.

VOICE ONE:

And I'm Pat²¹ Bodnar. To send us e-mail, write to [email protected]. Listen next week for more news about science in Special English on the Voice of America.

1 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。

2 influenza   

n.流行性感冒，流感

参考例句：

• They took steps to prevent the spread of influenza.他们采取措施
• Influenza is an infectious disease.流感是一种传染病。

3 highly   

adv.高度地，极，非常；非常赞许地

参考例句：

• It is highly important to provide for the future.预先做好准备非常重要。
• The teacher speaks very highly of the boy's behaviour.老师称赞这个男孩的表现。

4 poultry   

n.家禽，禽肉

参考例句：

• There is not much poultry in the shops. 商店里禽肉不太多。
• What do you feed the poultry on? 你们用什么饲料喂养家禽?

5 migratory   

n.候鸟，迁移

参考例句：

• Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
• This does not negate the idea of migratory aptitude.这并没有否定迁移能力这一概念。

6 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。

7 protective   

adj.防护的，保护的

参考例句：

• A mother naturally feels protective towards her children.做母亲的天生要保护自己的孩子。
• We feel safe with a protective device in the house.我们因为家里有了防护装置而感到安全。

8 fiber   

n.纤维，纤维质

参考例句：

• The basic structural unit of yarn is the fiber.纤维是纱的基本结构单元。
• The material must be free of fiber clumps.这种材料必须无纤维块。

9 swelling   

n.肿胀

参考例句：

• Use ice to reduce the swelling. 用冰敷消肿。
• There is a marked swelling of the lymph nodes. 淋巴结处有明显的肿块。

10 mister   

n.(略作Mr.全称很少用于书面)先生

参考例句：

• Mister Smith is my good friend.史密斯先生是我的好朋友。
• He styled himself " Mister Clean ".他自称是“清廉先生”。

11 sabotage   

n.怠工，破坏活动，破坏；v.从事破坏活动，妨害，破坏

参考例句：

• They tried to sabotage my birthday party.他们企图破坏我的生日晚会。
• The fire at the factory was caused by sabotage.那家工厂的火灾是有人蓄意破坏引起的。

12 fertilizer   

n.肥料，化肥

参考例句：

• Fertilizer enriches the soil.肥料使土壤肥沃。
• Get some more fertilizer for the garden.给花园再多施些肥料。

13 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

14 resistance   

n.抵抗力，反抗，反抗行动；阻力，电阻；反对；adj.抵抗的

参考例句：

• Very little resistance was put up by the enemy.敌人没怎么进行抵抗。
• An aircraft has to overcome the resistance of the air.飞机须克服空气的阻力。

15 estimate   

n.估计，估量；评价，看法；vt.估计，估量

参考例句：

• We estimate the cost to be five thousand dollars.我们估计费用为5000美元。
• The lowest estimate would put the worth of the jewel at ＄200.按最低的评估这块宝石也值200美元。

16 continually   

adv.不间断地，不停地；多次重复地

参考例句：

• The other kids continually taunted him about his size.其他孩子不断地耻笑他的个头儿。
• The US is continually building up its armed forces.美军正持续加强它的三军。

17 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。

18 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。

19 finding   

n.发现，发现物；调查的结果

参考例句：

• The finding makes some sense.该发现具有一定的意义。
• That's an encouraging finding.这是一个鼓舞人心的发现。

20 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。

21 pat   

n.轻拍，拍打声；vt.轻拍，拍打；vi.轻跑，轻击；adv.适时，彻底；adj.油腔滑调的，恰好的，合适的

参考例句：

• Could you hear the pat?你能听到轻轻的拍击声吗？
• He gave her a reassuring pat on the shoulder. 他轻拍了一下她的肩膀让她放心。