|Class 9 Biology Why Do We Fall Ill||Infectious disease|
The diseases caused due to the infections spread by microbes such as bacteria, virus, fungi, etc. are called infectious diseases.
For example, chicken pox, AIDS, dengue, fever, cold are caused by virus.
Fig. Chicken Pox
Typhoid, cholera, tuberculosis are caused by bacteria.
Malaria, kala azar are caused by protozoa.
These diseases are spread by the microbes.
They can be transferred from an infected person to a healthy by several means. Therefore, infectious diseases are also called communicable diseases.