VOA慢速英语2021--科学家发现抗药性疟疾的证据

Scientists Find Evidence of Drug-Resistant¹ Form of Malaria²

Researchers in Uganda have discovered evidence of a drug-resistant form of malaria.

Health officials fear the finding could make the top drug used against the disease useless if the resistant form keeps spreading.

Scientists in Uganda examined blood samples from patients treated with artemesinin, the main medicine used for malaria in Africa in combination with other drugs.

They found that by 2019, nearly 20 percent of the samples had genetic³ changes suggesting the treatment was ineffective. Lab tests showed it took much longer for those patients to get rid of the organisms that cause malaria.

Drug-resistant forms of malaria have previously⁴ been found in Asia. So, health officials were watching for signs in Africa, which makes up more than 90 percent of the world's malaria cases. Some drug-resistant forms of malaria have also shown up in Rwanda.

"Our findings suggest a potential risk of cross-border spread across Africa," the researchers wrote in a study recently published in the New England Journal of Medicine.

The scientists examined 240 blood samples over a three-year period. They found evidence that the drug-resistant forms first appeared in Uganda rather than being imported from elsewhere.

Malaria is spread by mosquito bites and kills more than 400,000 people every year. Most of the victims are children under age 5 and pregnant women.

Dr. Philip Rosenthal is a professor of medicine at the University of California, San Francisco. He told The Associated Press that the new findings in Uganda -- following the past results in Rwanda -- "prove that resistance really now has a foothold in Africa."

Rosenthal, who was not involved in the new study, said there is likely undiscovered drug resistance elsewhere on the continent. He said drug-resistant versions of malaria appeared in Cambodia years ago and have now spread across Asia. He predicted a similar path for the disease in Africa, with possibly deadlier results because of the heavy presence of malaria in Africa.

Dr. Nicholas White is a professor of medicine at Mahidol University in Bangkok, Thailand. He wrote a commentary on the results that appeared with the study. He described the findings about a drug resistant malaria as "unequivocal."

Based on the results, White suggested a change in the treatment method for malaria. He said that instead of combining artemisinin with one or two other drugs, doctors should now use three. This same method is often used to treat tuberculosis⁵ and HIV.

White urged public health officials to take steps now to reduce the spread of drug-resistant malaria. Among other measures, he suggested increased monitoring and support for research into new drugs.

"We shouldn't wait until the fire is burning to do something," he said. But, he added: "That is not what generally happens in global health." As an example, he pointed⁶ to recent failures to stop the worldwide spread of COVID-19.

Words in This Story

sample – n. a small amount of something that gives you information about the thing it was taken from

potential – adj. having or showing the capacity to become or develop into something in the future

mosquito – n. a small flying insect that feeds of the blood of people and animals

foothold – n. a safe position from which you can make more progress

unequivocal – n. clear and certain

monitor – v. to watch something carefully and record the results

1 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。

2 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。

3 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。

4 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

5 tuberculosis   

n.结核病，肺结核

参考例句：

• People used to go to special health spring to recover from tuberculosis.人们常去温泉疗养胜地治疗肺结核。
• Tuberculosis is a curable disease.肺结核是一种可治愈的病。

6 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。