VOA慢速英语2011--Seeking a Better Way for African Farmers to Fight a Fever

Agriculture Report - Seeking a Better Way for African Farmers to Fight a Fever

农业报道 - 寻求对抗东海岸热疾病的更好办法

This is the VOA Special English Agriculture Report.

这里是美国之音慢速英语农业报道。

East Coast fever kills hundreds of thousands of cattle in eastern and central Africa every year. The animals become infected when they get bitten by ticks carrying the parasite¹ that causes the disease. A parasite is an organism that feeds on other organisms.

非洲东部和中部地区每年有数万头牛因“东海岸热”致死。当牛被携带了可以导致该疾病的寄生虫的蜱虫叮咬后就会感染。寄生虫是一种以其它生物为食的生物。

Donald Knowles directs the animal disease research unit in the Agricultural Research Service, part of the United States Department of Agriculture. The service is working with the International Livestock² Research Institute in Kenya to find better ways to prevent parasitic³ diseases in cattle. Dr. Knowles is also a professor at Washington State University.

唐纳德·诺尔斯（Donald Knowles）负责美国农业部下属的农业研究服务中心的疾病研究部门。该部门与肯尼亚国际牲畜研究所合作，寻找防止牛类寄生虫病的更好办法。诺尔斯博士还是美国华盛顿州立大学的一名教授。

He points out that East Coast fever is not a contagious⁴ disease, so animals cannot give it to each other.

他指出，东海岸热不是一种传染性疾病，所以动物间不会互相传染。

DONALD KNOWLES: "You need a tick to transmit from one infected cow to the other. They won’t transmit just by standing⁵ next to each other. You need a tick to move it between them."

诺尔斯：“被感染的牛传染给其它牛需要蜱虫来传播。这种疾病无法通过紧挨在一起的牛群直接传播，需要蜱虫将其传播至其它牛。”

Farmers in parts of Africa use a vaccination⁶ method against East Coast fever known as infect and treat. First they infect animals with live parasites⁷. Then they treat them with drugs to help them recover.

非洲部分地区的农民使用一种被称为先感染再治疗的疫苗接种方法对抗东海岸热。他们首先用活体寄生虫感染动物，然后通过药物治疗帮助动物康复。

That way, explains Dr. Knowles, the animal becomes immunized or vaccinated⁸ against a full case of the deadly fever. But there are problems with this method of vaccination. Uninfected ticks that bite the vaccinated animal can still get infected and spread the parasite to other animals.

诺尔斯博士解释到，通过这种方式，动物对各类致命发热都具备免疫力。但这种疫苗接种方法也有问题。未受感染的蜱虫叮咬接种过的动物后仍然会被感染，继而传播寄生虫到其它动物。

DONALD KNOWLES: "Once a cow is infected with this parasite, all the data indicates that the cow stays infected for life. And the consequences of that, the big deal about that is, that means that cow, even a cow that has been vaccinated, now it’s protected against the disease, but it can still transmit. See it’s infected for life. And so that animal is still a source of transmission."

诺尔斯：“一旦牛被这种寄生虫感染，所有数据都表明，这头牛会终生保持被感染状态。这意味着的最大的问题是，这头牛，即使是接种过疫苗，能够预防这种疾病，但却仍然可以传播疾病，它终生被感染。所以这头牛仍然是一个传染源。”

And that is not the only problem with this method of vaccination.

这还不是这种疫苗接种方法的唯一问题。

DONALD KNOWLES: "One of the things in using live vaccines¹⁰ is that they usually require cold storage. And that adds to the cost of it, and also adds to the difficulty of using it in places like Africa."

诺尔斯：“使用活性疫苗的问题之一就是它们通常需要冷藏。这增加了疫苗的使用成本，也增加了它在非洲这种地方使用的难度。”

For more than four years, American and Kenyan scientists have studied diseases carried by ticks. The scientists in the United States centered their work on the parasite that causes Texas cattle fever. This fever is common to the Americas.

四年多来，美国和肯尼亚科学家对蜱虫携带的疾病进行研究。美国科学家将工作重点放到了引发德州牛类发热的寄生虫上。这类发热在美洲很是常见。

This year, the scientists began a new study in Africa. The study is aimed at developing a new vaccine⁹ for the East Coast fever parasite. Dr. Knowles says their goal is a vaccine that does not require infecting and treating animals or the need for cold storage.

今年，科学家在非洲开始了一项新研究，目的是开发一种针对东海岸热的新型疫苗。诺尔斯博士表示，他们的目标是开发一种不需要先感染再治疗的疫苗，或不需要冷藏的疫苗。

And that’s the VOA Special English Agriculture Report, written by Jerilyn Watson. We have transcripts¹¹, MP3s and now PDFs for e-readers at voanews.cn -- VOA's daily source of news and information for people learning English. Find us on Facebook, Twitter and YouTube at VOA Learning English. I'm Doug Johnson.

1 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。

2 livestock   

n.家畜，牲畜

参考例句：

• Both men and livestock are flourishing.人畜两旺。
• The heavy rains and flooding killed scores of livestock.暴雨和大水淹死了许多牲口。

3 parasitic   

adj.寄生的

参考例句：

• Will global warming mean the spread of tropical parasitic diseases?全球变暖是否意味着热带寄生虫病会蔓延呢？
• By definition,this way of life is parasitic.从其含义来说，这是种寄生虫的生活方式。

4 contagious   

adj.传染性的，有感染力的

参考例句：

• It's a highly contagious infection.这种病极易传染。
• He's got a contagious laugh.他的笑富有感染力。

5 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

6 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。

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 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？

9 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。

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 transcripts   

n.抄本（ transcript的名词复数 ）；转写本；文字本；副本

参考例句：

• Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样，都是染色体DNA的转录产物。 来自辞典例句
• You can't take the transfer students'exam without your transcripts. 没有成绩证明书，你就不能参加转学考试。 来自辞典例句