epidemics
If there is an epidemic of a particular disease somewhere, it affects a very large number of people there and spreads quickly to other areas.
A flu epidemic is sweeping through Moscow.
一场流感正席卷莫斯科。
a killer epidemic of yellow fever.
一场致命的黄热病流行。
A UN study warns the AIDs epidemic is nowhere near its peak.
一份联合国的研究警告说艾滋病的流行还远未达到其顶峰。
If an activity that you disapprove of is increasing or spreading rapidly, you can refer to this as an epidemic of that activity.
an epidemic of serial killings.
连环杀人的猖獗。