Infectious Diseases are caused by pathogens.

pathogens are micro-organisms that cause disease.
they include bacteria, protozoa, fungi and all viruses

Pathogens can spread in different ways:

Water

- some pathogens are picked up by drinking or bathing in dirty water.
- Cholera is a bacterial infection that causes diarrhoea and dehydration. It's spread when drinking water is contaminated with diarrhoea of other sufferers.

Food

- eating contaminated food.
- e,g Salmonella bacteria cause food poisoning and are found in food that has been kept too long or not cooked properly.

Air

- carried in air droplets when you cough or sneeze
E.g, the influenza virus that causes flu to spread this way.

Contact

-touching contaminated surfaces including the skin.
-E.g , athletes foot is a fungus which makes skin itch and flake off. it is spread by shower floors and towels.

Body Fluids

-blood
-sharing needles to inject drugs
-breast milk
-semen eg The HIV virus that causes AIDS.

Animal Vectors

-Vectors are animals that spread disease
- Anopheles mosquito- carries the protozen that causes malaria (damages the brain and kidneys)
- House Fly- carries bacterium that causes dysentery (severe diarrhoea).

	Created by daniifarrell over 10 years ago

GCSE Biology Core (Topic 3 Inter-relationships) Note on Disease and Cure, created by daniifarrell on 27/12/2013.

Disease and Cure