Communicable diseases

• what are communicable diseases

  disease that can be passed onto others
• what causes communicable disease

  pathogens including

  • ciruses
  • bacteria
  • protisits
  • fungi
• viruses

  • very small
  • move into cells and use biochemistry of it to make copies of itself
  • leads to cell bursting and releasing copies into the bloodstream
  • damage to cells makes the host feel ill
• bacteria

  • small
  • multiply quickly through dividing by a process called binary fission
  • produce harmful toxins
• protists

  • some are parasitic meaning they use humans and animals as their hosts
• fungi

  • single celled or have thread-like structures (hyphae)
  • produce spores which can be spread to other organisms
• measles

  • symptoms = fever, red skin rash, pneumonia
  • spread = droplet infection
  • prevented = vaccinations for young children
• HIV

  • symptoms = flu-like, leads to AIDS
  • spread = sexual contact or exchange of bodily fluids such as blood
  • prevented = condoms, not sharing needles, screening blood, antiretroviral drugs
• tobacco mosaic virus (plant pathogen affecting species of plants)

  • symptoms = discolouration of leaves, affecting part cannot photosynthesise
  • spread = contact between diseased plants and healthy plants, insects act as vectors
  • prevented = good field hygiene, pest control, TMV resistant strains
• salmonella food poisoning

  • symptoms = fever, stomach cramps, vomiting, diarrhoea
  • spread = bacteria in raw meat and eggs, unhygienic conditions
  • prevented = poultry are vaccinated against salmonella, keep raw meat away from cooked food, wash hands and surfaces when handling raw poultry
• gonorrhoea

  • symptoms = thick yellow or green discharge from penis or vagina, pain when urinating
  • spread = unprotected sexual contact
  • prevented = contraception such as condoms and antibiotics
• rose black spot

  • symptoms = purple or black spots on leaves of rose plants, leaves turn yellow and drop early
  • spread = spores of fungus are spread in water
  • prevented = fungicides or stripping the plant of affected leaved (burnt)
• malaria

  • symptoms = fevers and shaking
  • spread = mosquito punctures skin to feed on the blood, protists enter human bloodstream via their saliva
  • prevented = insecticide coated insect nets while sleeping