Viral diseases

• Measles:

  • Spread by inhalation of droplets from sneeze or cough
  • Develop red skin rash and fever
  • Can be fatal if complications arise - pneumonia, swelling of brain
  • Young children are vaccinated against measles
• HIV:

  • Spread by sexual contact or exchange of bodily fluids - e.g sharing needles when taking drugs

  1. Causes flu-like syptoms
  2. Unless controlled by antiretroviral drugs, virus attacks immune cells
  3. Late stage HIV or AIDS occurs when immune system is badly damaged and can no longer cope with other infections or cancers
• Tobacco mosaic virus:

  • Affects many species of plants e.g tomatoes
  • Causes mosaic pattern of discolouration on leaves
  • Affects growth of plant because of lack of photosynthesis