Pathogens

• Communicable diseases are spread from person to person. They are infectious
• Communicable diseases are spread by pathogens
• Pathogens are microorganisms that cause infectious diseases
• What are some examples of pathogens?

  Viruses

  Bacteria

  Fungi

  Parasites
• Bacteria can release harmful chemicals called toxins
• Toxins damage tissues and makes us feel ill
• Viruses can not reproduce by themselves. They only reproduce once inside a host cell
• How do viruses damage cell

  The virus invades the cell

  The virus reproduces

  This is very damaging to the cell. When the virus leaves the cell, it can cause the cell to burst open and die
• How do pathogens spread?

  In the air

  In water

  Direct contact
• How can we reduce the spread of pathogens?

  washing hands

  Isolation

  Vaccines

  Pesticides