Chain of infection

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Diagram showing the chain of infection for germs

Germs (agent)

  • Bacteria
  • Viruses
  • Parasites

Where germs live (reservoir)

  • People
  • Animals/Pets (dogs, cats, reptiles)
  • Wild animals
  • Food
  • Soil
  • Water

How germs get out (portal of exit)

  • Mouth (vomit, saliva)
  • Cuts in the skin (blood)
  • During diapering and toileting stool

Germs get around (mode of transmission)

  • Contact (hands, toys, sand)
  • Droplets (when you speak, sneeze or cough)

How germs get in (portal of entry)

  • Mouth
  • Cuts in the skin
  • Eyes

Next sick person (susceptible host)

  • Babies
  • Children
  • Elderly
  • People with a weakened immune system
  • Unimmunized people
  • Anyone

Cycle repeats

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