CNN News: 病毒如何传播
- 参考译文
- 听力原文
How does a virus spread? There are plenty of ways. It could be - - a sneeze, a handshake, to name a few.
病毒是如何传播的?有很多方法。它可能是——一个喷嚏，一次握手，等等。
Then there's our habits -- washing our hands, not touching our face. Even the climate may play a role in determining how far and how fast an infection spreads.
还有我们的习惯——洗手，不摸脸。气候也可能在决定感染传播的距离和速度方面发挥作用。
Scientists have summed up how far an infection can spread with a number. It's called R0. A number greater than one indicates it'll grow, less than one indicates the outbreak will die out.
科学家们已经用数字总结出传染病可以传播多远。它叫做R0。大于1的数字表示疫情会扩大，小于1的数字表示疫情会消失。
Scientists determine the number with a formula that brings together all the environmental and biological factors.
科学家们将所有的环境和生物因素结合在一起，得出了这个数字。
This is how it looks in reality -- an infection is introduced to human from animal, let's say, the bigger the R0 number, the more people of virus can infect. So an R0 of two means that patients zero will on average infect two other people who in turn can infect another two people and so on.
这是在现实中的样子——假设感染从动物被引入到人类，R0值越大，病毒感染的人就越多。R0等于2意味着患者0平均会感染另外两个人，而这两个人又会感染另外两个人，以此类推。
An infection like measles sits higher of the spectrum with an R0 of between 12 and 18.
麻疹等感染的R0值在12到18之间，处于较高的范围。
At the lower end is something like Ebola with an R0 number of 1.5 to 2.5.
较低的是埃博拉病毒，R0值为1.5到2.5。
And while the flu varies from year to year, one study reports it averages to 1.2.
虽然流感每年都一样，但一项研究报告称，平均每年有1.2人感染。
But as various factors change, so too does the R0. Take SARS. When it first emerged, SARS spread rapidly with a high R0, but people were only contagious once symptoms started showing. Once people were informed about the symptoms, they started coming to the hospital earlier. People could check themselves into hospital before infecting other people, pushing the R0 number below one.
但是随着各种因素的变化，R0也在变化。当SARS刚出现时，它以高数值R0迅速传播，但人们只有在症状开始出现时才知道它具有传染性。一旦被告知这些症状，们可以在感染他人之前先到医院检查，将R0数值压到1以下。
And that is how a virus can spread.
这就是病毒传播的方式。
How does a virus spread? There are plenty of ways. It could be - - a sneeze, a handshake, to name a few.
Then there's our habits -- washing our hands, not touching our face. Even the climate may play a role in determining how far and how fast an infection spreads.
Scientists have summed up how far an infection can spread with a number. It's called R0. A number greater than one indicates it'll grow, less than one indicates the outbreak will die out.
Scientists determine the number with a formula that brings together all the environmental and biological factors.
This is how it looks in reality -- an infection is introduced to human from animal, let's say, the bigger the R0 number, the more people of virus can infect. So an R0 of two means that patients zero will on average infect two other people who in turn can infect another two people and so on.
An infection like measles sits higher of the spectrum with an R0 of between 12 and 18.
At the lower end is something like Ebola with an R0 number of 1.5 to 2.5.
And while the flu varies from year to year, one study reports it averages to 1.2.
But as various factors change, so too does the R0. Take SARS. When it first emerged, SARS spread rapidly with a high R0, but people were only contagious once symptoms started showing. Once people were informed about the symptoms, they started coming to the hospital earlier. People could check themselves into hospital before infecting other people, pushing the R0 number below one.
And that is how a virus can spread.
