谁最容易遭受新冠病毒重创？年龄不是唯一危险因素

Older people remain most at risk of dying from the new coronavirus disease, COVID-19. The majority of people who get COVID-19 have minor¹ or moderate sickness. But "majority" does not mean "all." So, who else should be concerned about contracting severe, even deadly, cases of COVID-19?

It may be months before scientists have enough data to say for sure who, aside from the old, is most at risk and why. But, medical experts have already learned some helpful information from numbers on early cases around the world.

Not just the old getting sick

In China, 80 percent of COVID-19 deaths were among people in their 60s or older.

This alone means some countries face higher percentages of deaths from the disease. Italy has the world's second oldest population after Japan. Italy has reported more than 80 percent of deaths in the country so far were among those 70 or older.

But, "the idea that this is purely² a disease that causes death in older people we need to be very, very careful with," said Dr. Mike Ryan. He is the World Health Organization's emergencies chief.

Between 10 and 15 percent of people under 50 have moderate to severe infections, he said last week.

"Young people are not invincible³," said the WHO's Maria Van Kerkhove. She noted⁴ that more information is needed about the disease in all age groups.

Italy reports 25 percent of its confirmed cases are among people ages 19 to 50. In Spain, about 33 percent are under the age of 44. In the U.S., the Centers for Disease Control and Prevention's first examination of cases found that 29 percent were ages 20 to 44.

Then there is the mystery of how the disease affects children. They have made up a small amount of the world's case counts to date. Most appear to get only mildly ill.

Another question is what part children play in spreading the virus. Researchers at Canada's Dalhousie University recently wrote in The Lancet Infectious Disease publication: "There is an urgent need for further investigation⁵ of the role children have in the chain of transmission."

Pre-existing conditions

Along with age, existing health conditions are a major predictor of who suffers most from COVID-19. In China, 40 percent of people who required critical care had health problems before they became infected. COVID-19 deaths in China were highest among people who already had heart disease, diabetes⁶ or chronic⁷ lung diseases.

Pre-existing health problems can also increase risk of infection. This includes people who have weak immune systems caused by things such as cancer treatment. Additional threats are likely to be discovered.

Italy reported that of the first nine people younger than 40 who died of COVID-19, seven were confirmed to have serious health issues such as heart disease.

Heart disease is a very general term. But, so far, it looks like those most at risk have serious cardiovascular disease such as congestive heart failure or severely⁸ blocked or hardened arteries⁹, said Dr. Trish Perl. She is infectious disease chief at UT Southwestern Medical Center.

Arteries are the largest tubes through which blood flows around the body.

Any sort of infection generally makes diabetes harder to control. But it is not clear why diabetics appear to be at greater risk with COVID-19.

As for preexisting breathing diseases, "this is really happening in people who have less lung capacity," Dr. Perl said.

Asthma¹⁰, a breathing condition that affects 300 million people worldwide, is also a special worry.

The gender¹¹ mystery

Several countries have observed that men are more likely to get severely sick from COVID-19. This is not a surprise to researchers. During the outbreaks of the coronavirus diseases SARS and MERS, scientists also found that men generally had more severe cases than women.

In China, a little more than half the COVID deaths have been among men. Some other parts of Asia report similar amounts. In Italy, men so far make up 58 percent of infections. And a report on Britain's first 200 coronavirus patients admitted to critical care said that about sixty-five percent were male.

One reason? Worldwide, men are more likely to have smoked more heavily and for longer periods than women. The European Center for Disease Prevention and Control is urging research into smoking's connection to COVID-19.

Sex hormones¹³ may be involved also. In 2017, American researchers who infected mice with SARS found that male mice were more likely to die. Estrogen -- a female sex hormone¹² -- seemed protective. When the mice had their ovaries removed, deaths among female mice increased.

Words in This Story

mild - n. not harsh or severe

invincible - adj. impossible to defeat or overcome

transmission - n. the act or process by which something is spread or passed from one person or thing to another

role - n. a part that someone or something has in a particular activity or situation

diabetes - n. a serious disease in which the body cannot properly control the amount of sugar in your blood because it does not have enough insulin

chronic - adj. continuing or occurring again and again for a long time

immune system - n. the system that protects your body from diseases and infections

asthma - n. a physical condition that makes it difficult for someone to breathe

hormones - n. natural substances produced in the body which influence the way the body grows or develops

ovary - n. one of usually two organs in women and female animals that produce eggs and female hormones

1 minor   

adj.较小(少)的，较次要的；n.辅修学科；vi.辅修

参考例句：

• The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
• I gave him a minor share of my wealth.我把小部分财产给了他。

2 purely   

adv.纯粹地，完全地

参考例句：

• I helped him purely and simply out of friendship.我帮他纯粹是出于友情。
• This disproves the theory that children are purely imitative.这证明认为儿童只会单纯地模仿的理论是站不住脚的。

3 invincible   

adj.不可征服的，难以制服的

参考例句：

• This football team was once reputed to be invincible.这支足球队曾被誉为无敌的劲旅。
• The workers are invincible as long as they hold together.只要工人团结一致，他们就是不可战胜的。

4 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。

5 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。

6 diabetes   

n.糖尿病

参考例句：

• In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。
• Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。

7 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

8 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。

9 arteries   

n.动脉( artery的名词复数 )；干线，要道

参考例句：

• Even grafting new blood vessels in place of the diseased coronary arteries has been tried. 甚至移植新血管代替不健康的冠状动脉的方法都已经试过。 来自《简明英汉词典》
• This is the place where the three main arteries of West London traffic met. 这就是伦敦西部三条主要交通干线的交汇处。 来自《简明英汉词典》

10 asthma   

n.气喘病，哮喘病

参考例句：

• I think he's having an asthma attack.我想他现在是哮喘病发作了。
• Its presence in allergic asthma is well known.它在过敏性气喘中的存在是大家很熟悉的。

11 gender   

n.（生理上的）性，（名词、代词等的）性

参考例句：

• French differs from English in having gender for all nouns.法语不同于英语，所有的名词都有性。
• Women are sometimes denied opportunities solely because of their gender.妇女有时仅仅因为性别而无法获得种种机会。

12 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。

13 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。