It's a devastating,

它是一种毁灭性的
frequently fatal infectious disease.

频繁发病的致命疾病
If smallpox occurred in your community,

如果你周围有人得了天花的话
about 30 percent of the people that acquire the disease

那么百分之三十的天花病人
would die from it;

会因此死亡
the other 70 percent could be disabled or permanently disfigured

剩下的百分之七十会成为残疾或永久毁容
as a result of the disease.

这都是天花造成的
It's an infectious disease; it is spread by--through the air.

它是一种传染病通过空气传播
So, it first infects you

所以只要吸入病原体
because you breathe in some of the infectious agent.

你就会被感染
Smallpox is a virus called variola, it's a virus that contains DNA.

天花是病毒引起的这种病毒含DNA
The name of the virus is variola.

病毒的名字叫天花病毒