The spread of disease

• Direct


  Event
• Rated to
• Fungi


  Rose Hackspot
• Fungi


  • Spread by water and wind
  • Symptoms: purple or black spots on leaves, which turn yellow and drop early
  • Reduces a plant's ability to photosynthesise, affecting growth
• Protists


  Malaria
• Protists


  • Spread by mosquitos feeding on the blood of infected people and spread the protist when they feed on another person
  • Organisms that spread disease by carrying pathogens between people are called vectors
• Prevention and treatment


  1. Fungicides

  2. Affected leaves removed and destroyed
• Malaria


  • Symptoms: recurrent episodes of fever
  • Can be fatal
• Prevention and treatment


  1. Prevent mosquito vectors breeding

  2. Mosquito nets to prevent bites

  3. Anti-malarial medicine
• Communicable disease


  Infectious disease
• Ways to prevent the spread of communicable diseases

  • Hygiene: hand washing, disinfecting surfaces and machinery, keeping raw meat separate, covering mouth when coughing/sneezing
  • Isolation: isolation of infected individuals - people, animals, and plants
  • Controlling vectors: destroying or controlling the population of the vector
  • Vaccination: vaccination can protect large numbers of individuals against diseases
• Vaccination


  Injecting small quantities of dead or inactive forms of a pathogen into the body
• Herd immunity


  If a large proportion of a population is vaccinated against a disease, the disease is less likely to spread, even if there are some unvaccinated individuals
• This stimulates white blood cells to produce the correct antibodies for that pathogen
• If the same pathogen re-enters the body, the correct antibodies can be produced quickly to prevent infection
• Sexually transmitted disease (STD)