Pathogen - Disease causing organism [Transmissible Diseases]

Transmitted Through -

  1. Direct Contact - One host to another directly [Blood or semen]
  2. Indirect Contact - Pathogen leaves host and is carried to another
Methods Examples
Droplets In Air Common Cold, Flu
Food/Water Cholera, Typhoid
Touching Contaminated Surfaces Athletes Foot, Salmonella
Insect Bites Malaria, Dengue

Body’s Defense-

Mechanical Barriers - Structures that make it difficult to enter

  1. Skin - Covers almost all parts of body preventing infection, can heal itself [scabs]
  2. Hairs in the nose - Make it difficult for pathogens to get into the lungs

Chemical Barriers - Substances produced by the body that kill or trap pathogens before disease is caused

  1. Mucus - Traps pathogens and then get removed through coughing
  2. Stomach acid - Kills any pathogens ingested

Cells - White blood cells prevent pathogens from reaching area of the body they can replicate in

  1. Phagocytosis - Engulfing and digesting
  2. Antibodies - Clump pathogens so they cant move easily, releasing chemicals to mark destruction

Controlling The Spread Of Diseases -

Measure Explanation
Hygienic Food Preparation Cool food - Slows down bacteria and fungi reproduction

Prepare food hygienically - Avoid contamination [Clean foods, surfaces, utensils]

Cook food well - Temperature Kills bacteria

Cover foods - Stop flies from landing

Wash hands | | Personal Hygiene | Wash with soap - Removes pathogens

Use tissues - Prevents spread

Wash hands after bathrooms | | Waste Disposal | Dispose in a sealed container - Vectors cant feed off food

Rubbish should be stored before collection away from human habitation | | Sanitation | Plumbing - Remove faeces and waste with pathogens away

Raw sewage should be treated - Remove solid waste and kill pathogens |