2007年VOA标准英语-Researchers in Kenya Discover New Weapon Agains

By Caroline Sawyer
Nairobi
09 August 2007

In Kenya, environmental researchers say they may have discovered a new, effective weapon to combat malaria¹.  The disease kills more than 1 million people worldwide each year.  Caroline Sawyer reports from our office in Nairobi that the weapon is a fish commonly found in Western Kenya.

Researchers hope the Nile Tilapia fish could help cut mosquito numbers in many areas of Africa plagued by Malaria

Researchers in Kisumu, on the shores of Lake Victoria, were studying insects and the environment when they discovered that by introducing a fish called the Nile Tilapia into ponds, mosquito numbers fell by more than 94 percent in less than a year.

These results are potentially life saving for local residents because malaria, which is spread through the bites of infected mosquitoes, kills more people here than any other disease.

According to the World Health Organization (WHO), approximately 40 percent of the world's population is at risk from the disease.  In sub-Saharan Africa, malaria, which is caused by a parasite², is responsible for over 3,000 deaths every day.  The majority of victims are children under five years old.

Malaria is spread by mosquitoes

Senior scientist from the International Center of Insect Physiology³ and Ecology, Dr. Francois Omlin is leading the Nile Tilapia study.  He is working in an area where 15 years ago, fish farming was a booming industry.  Omlin says the farming business collapsed⁴ leaving only stagnant⁵ water behind which is ideal for mosquito breeding.    

"We were shocked to see how many malaria larvae⁶ were there and felt it was critical to reactivate those fish ponds," he noted⁷.  "Of course, for that the ideal thing is to have a fish that is not only a good larvae eater, but also [the types] people like to eat, and the farmers can make an income [with]."

The number of people suffering from malaria has increased dramatically in the last 10 years.  Scientists say this is partly due to the parasite's ability to become resistant⁸ to drugs, but they add that population movements and climate change also contribute to the rise.  Researchers are working on a vaccine⁹, but progress has been slow.

The most effective way to prevent malaria is by sleeping under insecticide-treated bed nets, but many poor people in Sub-Saharan Africa cannot afford them.

Omlin's research on the Nile Tilapia published Thursday warns that this particular fish will not be able to help everyone.

"One has to operate with indigenous¹⁰ fish in order not to destroy or to affect the ecological¹¹ balance in the environment," he explained.  "One has to go local in a proper sense specific to find out which fish species are ideal and then make some very simple tests with that fish.  Is that fish useful to the people?  Do they like it for eating? Is it a good mosquito vacuum cleaner?"

Omlin says he hopes his work will encourage research on other indigenous fish that could help in other parts of the world.  The United Nations estimates that malaria costs African countries $12 billion annually¹².

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 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。

3 physiology   

n.生理学，生理机能

参考例句：

• He bought a book about physiology.他买了一本生理学方面的书。
• He was awarded the Nobel Prize for achievements in physiology.他因生理学方面的建树而被授予诺贝尔奖。

4 collapsed   

adj.倒塌的

参考例句：

• Jack collapsed in agony on the floor. 杰克十分痛苦地瘫倒在地板上。
• The roof collapsed under the weight of snow. 房顶在雪的重压下突然坍塌下来。

5 stagnant   

adj.不流动的，停滞的，不景气的

参考例句：

• Due to low investment,industrial output has remained stagnant.由于投资少，工业生产一直停滞不前。
• Their national economy is stagnant.他们的国家经济停滞不前。

6 larvae   

n.幼虫

参考例句：

• Larvae are parasitic on sheep.幼虫寄生在绵羊的身上。
• The larvae prey upon small aphids.这种幼虫以小蚜虫为食。

7 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。

8 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

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 indigenous   

adj.土产的，土生土长的，本地的

参考例句：

• Each country has its own indigenous cultural tradition.每个国家都有自己本土的文化传统。
• Indians were the indigenous inhabitants of America.印第安人是美洲的土著居民。

11 ecological   

adj.生态的，生态学的

参考例句：

• The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
• Each animal has its ecological niche.每种动物都有自己的生态位.

12 annually   

adv.一年一次，每年

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。
• They celebrate their wedding anniversary annually.他们每年庆祝一番结婚纪念日。