What are the different means by which infectious diseases are spread?
The different means by which infectious diseases spread are: (a) Through air: They are also called air-borne diseases. The air carries bacteria, virus and the diseases that can be caused are: common cold, influenza, tuberculosis etc. (b) Through food and water: When one eats/drinks contaminated food/water, that contains bacteria, virus, worm etc. it can cause diseases like cholera typhoid, hepatitis. (c) Through contact: Many diseases spread by contact of infected person with the healthy person. Example, fungal infections, skin diseases, scabies etc. (d) By sexual contact: Many diseases can be transmitted, example, syphilis, AIDS. (e) By body fluids: Fluids like blood, semen, mother’s milk, when infected, can also cause diseases. Example, AIDS. (f) Vectors: The organism that spreads a disease by carrying pathogens from one place to another is called vector. Example, mosquitoes are vectors that carry pathogens like protozoa.
