When a large number of people over much wider area become victims of an infectious disease it is called epidemic. Certain types of vims can cause epidemics.

Viral diseases affect mankind:

1. People loss their lives due to viral diseases.
2. Compared to general diseases, viral diseases spread faster and in a wider area.
3. Till date thousands have been victim of diseases like dengue, Ebola, Swine flu, Influenza, etc.
4. People get highly terrified on the spread of these diseases owing to innumerable deaths associates with such diseases.
5. For example, in earlier times, lakhs of people had become victims of plague.
6. With advanced cure methods, newly invented anti-viral serums and other medicines the world is now able to control such deadly diseases at a large extent.
7. For example, during the plague epidemic of Surat in September, 1994 and recent epidemic of swine flu and dengue many agencies took preventive steps and saved lives and several people.
8. However, the sad fact is that new vimses keep on affecting mankind and many a times they cannot be controlled with the existing medicines. This leads to mass deaths.