10.1 - Communicable Disease & Pathogens

Pathogens

• A pathogen is a microorganism that causes disease.
• The diseases caused by pathogens can be passed from one host to another, so they're called transmissible diseases (also known as infectious or communicable diseases).
• Both animals and plants can be infected by pathogens.

How pathogens spread

• Pathogens spread from host to host in several general ways.
• The same routes apply to both animals and plants.

Routes of spread

• Air - Carried through the air, often in the tiny droplets released when an infected person coughs or sneezes
• Water and food - Picked up from contaminated water or food
• Direct contact - Passed by touching an infected organism
• Contaminated surfaces - Picked up indirectly by touching a surface or object that carries the pathogen
• Body fluids - Passed through contact with blood and other body fluids
• Animal vectors - Carried from host to host by animals such as insects, which transfer the pathogen without catching the disease themselves