Harmful Microorganisms

Communicable Disease: A disease which can spread from one person to another is called communicable disease.

Infectious Disease: A disease which is caused by an attack from microbes is called infectious disease.

Pathogen

A microbe which causes disease is called a pathogen. Some examples of pathogens are as follows:

Pathogen	Disease	Mode of Transmission
Plasmodium	Malaria	Spreads through bite of female Anopheles mosquito.
Dengue virus	Dengue	Spreads through bite of Aedes mosquito.
Common cold virus	Common cold	Through air; when someone coughs or sneezes.
Many bacteria	Cholera, diarrhoea	Through contaminated food and water.
Hepatitis B virus	Hepatitis B	Through exchange body fluids.
HIV	AIDS	Through exchange of body fluids.
Bacillus anthracis	Anthrax (in animals)	Through contact.

Malaria and dengue spread through mosquitoes. So, breeding of mosquito should be prevented.
Don’t allow water to stagnate in surroundings because mosquitoes lay eggs in stagnant water.
Frequently clean the water in cooler.
Keep the overhead tank covered.
Keep the drains properly covered.
Fill any ditch with sand or soil.
Use mosquito repellant creams and mosquito nets to prevent mosquito bite.

Diseases caused by microbes in plants
Microbes	Disease	Mode of transmission
Bacteria	Citrus canker	Air
Fungi	Rust of wheat	Air, seeds
Virus	Yellow vein mosaic of Okra	Insects