Communicable Disease

• Pathogens


  Microorganisms that enter the body and cause disease
• Pathogens


  • Cause communicable (infectious) diseases that can easily spread
  • Can infect both plants and animals
• Bacteria


  Very small living cells that can reproduce rapidly inside the body and produce toxins that damage cells and tissues
• Viruses


  Not cells, much smaller than bacteria, live inside cells and replicate using the cell's machinery, then burst the cell causing damage
• Protists


  Single-celled eukaryotes, some are parasites that live on or inside other organisms and can be transferred by a vector
• Fungi


  • Can be single-celled or have a body made of hyphae (thread-like structures) that can penetrate skin and plant surfaces, produce spores that can spread
• How pathogens can be spread

  1. Water-borne (e.g. cholera)

  2. Air-borne (e.g. influenza)

  3. Direct contact (e.g. athlete's foot)
• Pathogens can be spread in many ways including water, air, and direct contact