Communicable diseases are the epidemic diseases that spread from infected living beings to the other healthy living beings. This occurs in human beings, animals and plants. Communicable diseases are caused by the microbes called pathogens. For example:
(i) Typhoid and Cholera are some communicable diseases caused in human beings due to microbes.
(ii) Rinderpest and foot and mouth disease are some communicable diseases caused in animals due to virus.
(iii) Rust of wheat and apple scab are some communicable diseases caused in plants due to fungus.