Pathogens

Pathogens

Pathogens are microorganisms (viruses, bacteria, protists, and fungi) that cause infectious disease.
There are various ways a disease can be spread in animals and plants:
- Direct contact: spread by physical contact
- Transfer of infected fluids: e.g. blood, saliva, semen
- Contaminated water: travels in unsterilised water
- Airborne: propelled through the air in tiny droplets of water through sneezing and coughing
- Food: pathogens in uncooked or spoiled food
- Via another animal: the animal is called a vector
The spread of disease can be reduced or prevented by:
- Sterilising water with chemicals or UV light
- Cooking food thoroughly and preparing it in hygienic conditions
- Disinfecting surfaces
- Treating infections, e.g. with antibiotics
- Vaccination
- Barrier method of contraception to prevent the spread of sexually transmitted diseases, e.g. condoms
Bacteria and viruses can reproduce rapidly inside the body.
- Bacteria can produce toxins that damage tissues and cause disease symptoms.
- Viruses live and reproduce inside cells, causing cell damage.

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