VOA慢速英语2021--From Epidemic to Pandemic to Endemic

 

The World Health Organization (WHO) declared the coronavirus crisis a "pandemic" on March 11 of 2020. The WHO's Director-General Tedros Adhanom Ghebreyesus said that day, "Pandemic is not a word to use lightly or carelessly." He was reminding people that the word is used only for the most extreme and dangerous spreads of disease.

Since the start of the pandemic, Johns Hopkins University reports, there have been more than 228 million confirmed cases of COVID-19 among the almost eight billion people on the planet. The number of deaths from the disease is about 4.7 million.

At the same time, new versions, or variants², of the SARS-CoV-2 virus that causes COVID-19 are developing and spreading very fast. In the United States, the Centers for Disease Control and Prevention (CDC) said the Delta³ variant¹ is the main cause of new COVID infections.

Governments and health officials around the world reacted to the crisis by establishing the largest vaccination⁴ program in history. Data collected by the Bloomberg company shows that by September, more than 5.9 billion shots of vaccine⁵ have been administered to people across 184 countries.

Many scientists, however, believe that the new coronavirus is here to stay. The science publication Nature recently reported the results of a poll it did with more than 100 scientists. Eighty-nine percent said they believed SARS-CoV-2 virus will become endemic, meaning it will continue to exist in some areas for years to come.

Michael Osterholm is an expert on epidemics⁷ at the University of Minnesota in Minneapolis. He told Nature that ending the existence of the virus right now is unrealistic. He compared it to trying to build "a stepping-stone pathway to the Moon."

Epidemic⁶ or pandemic

The World Health Organization defines pandemics, epidemics, and endemics based on a disease's rate of spread.

For example, the Ebola outbreak that spread within West African countries from 2014-2016 was called an epidemic.

In 2016, the world's health agency declared that the Zika virus was a "Public Health Emergency of International Concern." The insects called mosquitos pass the disease to humans when they bite them. Zika was first discovered in Africa and Asia before spreading to Brazil and other South American countries.

Some considered Zika an epidemic while others view it as a pandemic like the current coronavirus health crisis.

The difference between an epidemic and a pandemic is not in the severity of the disease, but the degree to which it has spread. A pandemic means a disease has spread to several countries around the world. Epidemic is used to mean disease spreads in smaller areas.

Researchers from Columbia University's School of Public Health wrote, "while an epidemic is large, it is also generally contained or expected in its spread, while a pandemic is international and out of control."

From pandemic to endemic

The word endemic came from the Greek word endēmos, meaning "in the population." In public health, it is used to describe a disease outbreak that is present and limited to an area. This makes the disease spread and rates easier to control.

Malaria⁸, for example, is considered an endemic in many warm, wet areas across countries in Asia, Africa, and South America. The H1N1 influenza⁹ virus is also endemic.

More than one-third of the scientists Nature polled thought it would be possible to end the COVID-19 pandemic from some countries while it continued to exist in others.

Christopher Dye studies epidemics at Britain's University of Oxford¹⁰. He said, "I guess COVID will be eliminated from some countries, but with a continuing (and maybe seasonal) risk of reintroduction from places where vaccine coverage¹¹ and public-health measures have not been good enough."

Laura Herrero and Eugene Madzokere are researchers from Australia's Griffith University. They wrote about the disease in the online news site The Conversation. The scientists said that with face coverings and vaccination, the COVID-19 pandemic "could disappear like smallpox¹² or polio did...." But they said the disease could also become endemic over time.

They said viruses are more likely to become endemic if they are adapted to "a local environment" of people with "low or zero immunity¹³." And vaccination rates will affect the progress of the disease. A low vaccine rate could permit the virus to continue at an epidemic level for longer, they wrote.

The scientists said once we see an unchanging level of SARS-CoV-2 passage in an area, we will know the pandemic has ended and the virus is endemic.

Words in This Story

poll - n. an activity in which several or many people are asked a question or a series of questions in order to get information about what most people think about something

guess - v. chiefly US, informal. to suppose or think (something) — usually used following the pronoun I

eliminate - v. to remove (something that is not wanted or needed) : to get rid of (something)

reintroduce - v. to return (an animal, disease, or plant) to the area where it used to live

adapt - v. to change your behavior so that it is easier to live in a particular place or situation

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 delta   

n.（流的）角洲

参考例句：

• He has been to the delta of the Nile.他曾去过尼罗河三角洲。
• The Nile divides at its mouth and forms a delta.尼罗河在河口分岔，形成了一个三角洲。

4 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。

5 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。

6 epidemic   

n.流行病；盛行；adj.流行性的，流传极广的

参考例句：

• That kind of epidemic disease has long been stamped out.那种传染病早已绝迹。
• The authorities tried to localise the epidemic.当局试图把流行病限制在局部范围。

7 epidemics   

n．流行病

参考例句：

• Reliance upon natural epidemics may be both time-consuming and misleading. 依靠天然的流行既浪费时间，又会引入歧途。
• The antibiotic epidemics usually start stop when the summer rainy season begins. 传染病通常会在夏天的雨季停止传播。

8 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。

9 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。

10 Oxford   

n.牛津（英国城市）

参考例句：

• At present he has become a Professor of Chemistry at Oxford.他现在已是牛津大学的化学教授了。
• This is where the road to Oxford joins the road to London.这是去牛津的路与去伦敦的路的汇合处。

11 coverage   

n.报导，保险范围，保险额，范围，覆盖

参考例句：

• There's little coverage of foreign news in the newspaper.报纸上几乎没有国外新闻报道。
• This is an insurance policy with extensive coverage.这是一项承保范围广泛的保险。

12 smallpox   

n.天花

参考例句：

• In 1742 he suffered a fatal attack of smallpox.1742年，他染上了致命的天花。
• Were you vaccinated against smallpox as a child?你小时候打过天花疫苗吗？

13 immunity   

n.优惠；免除；豁免，豁免权

参考例句：

• The law gives public schools immunity from taxation.法律免除公立学校的纳税义务。
• He claims diplomatic immunity to avoid being arrested.他要求外交豁免以便避免被捕。