VOA慢速英语--禽流感感染率上升显示出快速变异的风险

Rise in Bird Flu Infections Show Risks of Fast-Changing Variants²

An increase in the number of people in China infected with bird flu this year is raising concern among experts. They say an earlier bird flu strain appears to have changed and may be more infectious to people.

The World Health Organization (WHO) says China has reported 21 human infections with the H5N6 strain of bird flu in 2021. That compares with only five reported cases last year.

The numbers are much lower than the hundreds infected with H7N9 in 2017. But the infections are serious, with many severely³ ill and at least six dead.

"The increase in human cases in China this year is of concern. It's a virus that causes high mortality," said Thijs Kuiken. He teaches at the Erasmus University Medical Center in Rotterdam, The Netherlands.

The WHO said in a statement earlier this month that most of those infected with the H5N6 virus had come into contact with poultry⁴. The WHO noted⁵ that there are no confirmed cases of human-to-human virus spread.

The statement added that further investigation⁶ was "urgently" required to understand the risk and the increase in human infections.

While human H5N6 cases have been reported, no outbreaks of H5N6 have been reported in poultry in China since February 2020.

China is the world's biggest poultry producer and top producer of ducks. These animals act as carriers for many flu viruses.

The Chinese Center for Disease Control and Prevention (CDC) could not be reached for comment on the rise in H5N6 human cases. But a study published on its website in September said the increasing spread of H5N6 is "a serious threat to the poultry industry and human health."

Bird flu viruses continuously spread in domestic and wild birds, but rarely infect people. However, the increase in changes of the viruses is a major concern. Experts worry that a variant¹ – or new version -- of the virus that spreads easily between people could cause a pandemic.

The largest number of H5N6 infections have been in China's southwestern Sichuan province. Cases have also been reported in neighboring Chongqing and Guangxi, as well as Guangdong, Anhui and Hunan.

At least 10 cases were caused by viruses very similar to the H5N8 virus that struck poultry farms across Europe last winter and killed wild birds in China. That suggests the latest H5N6 infections in China may be a new variant.

Thijs Kuiken said, "It could be that this variant is a little more infectious (to people)...or there could be more of this virus in poultry at the moment and that's why more people are getting infected."

Four of the people who developed the virus in Sichuan raised poultry at home and had been in contact with dead birds, according to a September report by China's CDC. Another had bought a duck from a live poultry market a week before developing signs of illness.

Filip Claes is with the Food and Agriculture Organization. He said China vaccinates⁷ poultry against bird flu. But he said the vaccine⁸ used last year may only partly protect against new viruses. He added that the vaccine may prevent large outbreaks, but still permit the virus to keep spreading.

China's Ministry⁹ of Agriculture and Rural Affairs did not respond to a Reuters request for comment.

Backyard farms in China are common, and many people still buy live chickens at markets.

In September, officials in Guilin city in the Guangxi area said trading of live poultry in 13 city markets had been suspended and that all trade would end within a year.

Words in This Story

strain – n. a group of closely related living things that look similar but possess one or more unique characteristics

poultry – n. birds such as chickens and ducks that are raised on farms for their eggs or meat

outbreak – n. a sudden start or increase of fighting or disease

domestic – adj. living with or under the care of human beings

province – n. any one of the large parts that some countries are divided into

backyard – n. an area in back of a house

1 variant   

adj.不同的，变异的；n.变体，异体

参考例句：

• We give professional suggestions according to variant tanning stages for each customer.我们针对每位顾客不同的日晒阶段，提供强度适合的晒黑建议。
• In a variant of this approach,the tests are data- driven.这个方法的一个变种，是数据驱动的测试。

2 variants   

n.变体( variant的名词复数 )；变种；变型；（词等的）变体

参考例句：

• Those variants will be preserved in the'struggle for existence". 这些变异将在“生存竞争”中被保留下来。 来自辞典例句
• Like organisms, viruses have variants, generally called strains. 与其他生物一样，病毒也有变种，一般称之为株系。 来自辞典例句

3 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。

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 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。

6 investigation   

n.调查，调查研究

参考例句：

• In an investigation,a new fact became known, which told against him.在调查中新发现了一件对他不利的事实。
• He drew the conclusion by building on his own investigation.他根据自己的调查研究作出结论。

7 vaccinates   

给…接种疫苗( vaccinate的第三人称单数 )； 注射疫苗，接种疫苗

参考例句：

• The coverage rates of BCG,DPT,measles and polio vaccinates are 99 42%,99 79%,99 26%,99 21%,respectively. 1995 年“四苗”单项接种率分别为BCG99.42% 、TOPV99.21% 、DPT99.79% 、MV99.26% , “四苗”全程率98.84% 。

8 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。

9 ministry   

n.(政府的)部；牧师

参考例句：

• They sent a deputation to the ministry to complain.他们派了一个代表团到部里投诉。
• We probed the Air Ministry statements.我们调查了空军部的记录。