VOA慢速英语--研究表明病毒引起儿童麻痹性疾病

Scientists have found the strongest evidence yet that a virus is to blame for a mysterious illness that can quickly paralyze children.

The very rare condition, called acute flaccid myelitis or AFM, is similar to the polio disease. The first reports of the disease came from the American state of California in 2012. Since then, the U.S. has experienced an increasingly bigger outbreak every other year, from late summer into autumn.

Doctors have long believed that certain viruses known as enteroviruses caused AFM. But they did not have enough evidence to prove it.

So researchers tried something new. They checked patients' spinal¹ fluid for signs the immune system had fought an invading virus. Children who got sick had antibodies that target enteroviruses.

Dr. Michael Wilson is with the University of California, San Francisco. He helped lead the research. He said the evidence did not prove their idea. But it was a powerful sign enteroviruses cause AFM.

His team reported the findings in the publication Nature Medicine.

Study co-writer Dr. Riley Bove is with the same university as Wilson. Bove's son developed AFM at age four. He noted², "If you don't have a cause, you can't have a vaccine³." Bove added that Wilson developed "a good enough microscope, in a sense, to find things they suspected were there."

About 590 cases of the illness have been confirmed in the U.S. since 2014. Cases increased that year, in 2016 and in 2018. Only a few were reported in the years in between. So far, there have been 22 cases this year.

Bove's son Luca demonstrates the pattern. His whole family caught a cold in the summer of 2014. A few days later, Luca woke up with weakness in his neck that traveled down his shoulder. Within days, he had body-wide paralysis⁴ and trouble breathing. He recovered slowly. Today, he still has some paralysis in his neck, shoulder and arm.

Experts believe either a germ or the body's reaction to a germ damages nerves in the spinal cords of patients like Luca. They are preparing for another possible increase of cases next summer.

Words in This Story

antibodies – n. substances produced by the body to fight disease

germ – n. a very small living thing that causes disease

immune – adj. not capable of being affected⁵ by a disease

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

paralyze – v. to make a person or animal unable to move or feel all or part of the body

spinal – adj. of, relating to, or affecting the spine

1 spinal   

adj.针的，尖刺的，尖刺状突起的；adj.脊骨的，脊髓的

参考例句：

• After three days in Japan,the spinal column becomes extraordinarily flexible.在日本三天，就已经使脊椎骨变得富有弹性了。
• Your spinal column is made up of 24 movable vertebrae.你的脊柱由24个活动的脊椎骨构成。

2 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。

3 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。

4 paralysis   

n.麻痹(症)；瘫痪(症)

参考例句：

• The paralysis affects his right leg and he can only walk with difficulty.他右腿瘫痪步履维艰。
• The paralysis affects his right leg and he can only walk with difficulty.他右腿瘫痪步履维艰。

5 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。