Chain of Infection (U1) Flashcards
What is the chain of infection?
- Etiological/infection agent
- Reservoir
- Portal of Exit
- Method of transmission
- Portal of entry
- Susceptible host
Etiological/infection definition?
Disease causing MO
Reservoir
Place where MOs thrive and survive (host)
- Ex. water, food, skin
Portal of exit definition?
Any way for a MO to leave the reservoir
- Ex. nose, mouth
Method of transmission definition?
Way for MOs to spread (in)direct
Portal of entry definition?
The place where the MO enters the body
Susceptible host definition?
Person susceptible to infection
- Compromised host= increased risk
Chain of infection definition?
Mode to understand how infection spreads
- Each link must be present
What are the two methods of transmission (contact)?
Indirect and direct
What are the different methods of direct transmission?
Person to person, animal to person and mother to unborn child
What is person to person?
Direct bacteria/virus/germ from one person to another
What is animal to person?
Bitten/scratched by an infected animal
- Death= extreme cases
- Animal waste can be hazardous
What is mother to unborn child?
Pregnant women may pass infectious diseases onto fetus via placenta
- Can be during labour/delivery via birth canal passage
What are the different methods of indirect transmission?
Inanimate object, vector, food borne, droplet transmission, airborne/particle transmission
What is inanimate object?
Pathogens linger (fomites)
What is vector?
Living organism, indirect carriers
- Ex. fleas
What is food borne?
Infection via contaminated food
- Improper storage, handling, prep
What is droplet transmission?
Through cough/sneeze, expels droplets through air
- Travels three feet, too large to stay in air
- Contacts mouth/nose/eyes
- Crowded/indoor environment can promote chance of droplet transmission
What is airborne transmission?
Travels through air because they’re smaller than droplets
- Particles suspended in air extended periods of time and travel air currents
- Breathe in airborne pathogen
What is blood borne transmission
Indirect- transferred via blood transfusion, needlesticks/improper sterilized equipment
Direct- contaminated blood of person contacts another person with broken skin (mucous membrane/crossing placental barrier)
