Communicable diseases

• Disease


  An illness or disorder of the body or mind that leads to poor health
• Communicable/infectious disease


  Disease caused by pathogens that can be spread between individuals within a population
• Non-infectious disease


  Long-term diseases that are not caused by pathogens
• Communicable diseases


  • Cholera
  • HIV/AIDS
  • Malaria
  • Tuberculosis
• Pathogen


  Microorganisms that can cause disease, including bacteria, viruses, fungi, and protoctists
• Bacteria


  • Diverse range of prokaryotic organisms
  • Some are non-pathogenic, others are pathogenic
  • Pathogenic bacteria do not always infect host cells, they can remain within body cavities or spaces
• Pathogenic bacteria


  • M. tuberculosis (causes tuberculosis in humans)
  • M. bovine (can transmit tuberculosis from cows to humans)
  • N. meningitidis (causes bacterial meningitis in humans)
• Viruses


  • Do not have a cellular structure
  • Cannot respire, produce ATP, replicate genetic material or synthesise protein
  • Infect host cells and hijack their machinery to replicate their own genetic material and proteins
• Viruses


  • Tobacco Mosaic Virus (TMV)
  • Influenza A, B, and C (cause the flu)
  • Human Immunodeficiency Virus (HIV)
• Protoctists


  • Unicellular eukaryotes
  • Plasmodium falciparum (causes severe malaria in humans)
  • P. infestans (causes potato blight)
• Fungi


  • Eukaryotic cells with cell walls and large central vacuoles
  • Their bodies consist of filaments known as hyphae that form a network and spread throughout a host/soil
  • Fungal diseases are much more common in plants than animals
• Common pathogens and related communicable diseases in humans


  • M. tuberculosis (tuberculosis)
  • M. bovis (tuberculosis)
  • N. meningitidis (bacterial meningitis)
  • Influenza A, B, C, and D viruses (influenza)
  • Human Immunodeficiency Virus (HIV/AIDS)
  • P. falciparum, P. Ovale, P. vivax, P. malariae (malaria)
  • T. verrucosum (cattle ringworm)
  • E. floccosum, T. rubrum, T. mentagrophytes (athlete's foot)
• Common pathogens and related communicable diseases in plants

  • Clavibacter michiganensis (ring rot in potato and tomato)
  • Tobacco mosaic virus (tobacco mosaic)
  • P. infestans (late blight in potato and tomato)
  • M. fijiensis (black sigatoka in bananas)