PMLS 2

Seite 1

CHAIN OF INFECTION

6-PART MODEL

Infectious Agent

Reservoir

Portal of exit

Mode of transmission

Portal of entry

Susceptibility host

3-PART MODEL

Source

Transmission

Host (susceptible)

Seite 2

6-PART MODEL

Infectious agent - Pathogenic microbe responsible for causing an infection

Examples:

viruses, bacteria, fungi, protozoa, and worms

2. Reservoir – Source of infectious agent

– Place where microbe can survive & grow or multiply

Examples:

humans, animals, food, water, soil, equipment

3. Portal of exit – A way an infectious agent is able to leave a reservoir host

Examples:

Secretions & exudates, tissue specimens, blood, feces, urine

4. Mode of transmission

Direct

~ Direct Contact - physical or sexual

~ Droplet transmission -

Indirect