4.1.2 Transmission of Communicable Pathogens

Question 1

How can diseases be transmitted

Answer 1

• Physical contact
• Droplets in air
• Spores

HIV
- Exchange of bodily fluids
- Sexual intercourse
- Blood donation
- Sharing needles
- Mother to child across placenta
- Breast milk

TB
- Inhaling droplet
- Meat and milk in poor countries

Malaria
- Protist
- Mostquitos
- Also blood transfusions

Question 2

Factors affecting disease transmissions

Answer 2

• Genetics
• Eg. Heterozygous people for sickle cell allele have resistance to malaria
• High population
• Hygiene
• Farmers who use monocultures can experience large disease outbreaks
• Weather and climate (harbouring vectors)
  Eg. Mosquitos like rain, humidity and high temps

Question 3

Difference between resistance and immunity

Answer 3

• Immunity is having antibodies from previous encounters
• Resistance is where an individual is exposed to the pathogen for the first time but do not develop disease